[ { "doi": "10.3389/FRSEN.2021.748362", "year": 2021, "title": "Atmospheric Correction of DSCOVR EPIC: Version 2 MAIAC Algorithm", "abstract": "The Earth Polychromatic Imaging Camera (EPIC) onboard the Deep Space Climate Observatory (DSCOVR) provides multispectral images of the sunlit disk of Earth since 2015 from the L1 orbit, approximately 1.5 million km from Earth toward the Sun. The NASAs Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm has been adapted for DSCOVR/EPIC data providing operational processing since 2018. Here, we describe the latest version 2 (v2) MAIAC EPIC algorithm over land that features improved aerosol retrieval with updated regional aerosol models and new atmospheric correction scheme based on the ancillary bidirectional reflectance distribution function (BRDF) model of the Earth from MAIAC MODIS. The global validation of MAIAC EPIC aerosol optical depth (AOD) with AERONET measurements shows a significant improvement over v1 and the mean bias error MBE = 0.046, RMSE = 0.159, and\r\n R\r\n = 0.77. Over 66.7% of EPIC AOD retrievals agree with the AERONET AOD to within (0.1 + 0.1AOD). We also analyze the role of surface anisotropy, particularly important for the backscattering view geometry of EPIC, on the result of atmospheric correction. The retrieved BRDF-based bidirectional reflectance factors (BRF) are found higher than the Lambertian reflectance by 815% at 443 nm and 12% at 780 nm for EPIC observations near the local noon. Due to higher uncertainties, the atmospheric correction at UV wavelengths of 340, 388 nm is currently performed using a Lambertian approximation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2021WR030612", "year": 2022, "title": "A Bayesian Fuzzy Clustering Approach for Design of Precipitation Gauge Network Using Merged Remote Sensing and Ground\u2010based Precipitation Products", "abstract": "A two-level clustering approach is proposed for optimal design/expansion of a ground-based precipitation monitoring network (GPN). It harnesses the advantages of Infinite Bayesian fuzzy clustering in the first level to partition the study area into homogeneous precipitation zones by considering structural/statistical characteristics and temporal variability of the observed precipitation. In the second level, an ensemble of hierarchical and partitional clustering techniques is considered in the time domain to effectively partition each zone into groups by considering weighted inter-site dissimilarities of precipitation. The dissimilarities account for correlation, temporal dynamics, and fuzzy mutual information of precipitation at existing stations and possible new gauge locations. Key station's location in each group is identified by a proposed ranking procedure that accounts for population density, land-use/landcover, and fuzzy marginal entropy of precipitation. For use with the approach, information on precipitation was derived for fine resolution ungauged grids covering the study area using random forest-based regression relationships developed for gauged grids between merged multiple satellite-based precipitation products (CHIRPS, IMERG) and ground-based precipitation measurements. The potential of the proposed approach over other clustering-based procedures is illustrated through a case study on a GPN comprising 1,128 gauges in Karnataka state (191,791 km2) of India. Potential locations for installing new gauges and areas where there is scope for relocating existing stations are identified. The proposed methodology appears promising and could be extended to design networks monitoring various other hydrometeorological variables.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/JTECH-D-20-0005.1", "year": 2020, "title": "The RELAMPAGO lightning mapping array: Overview and initial comparison with the geostationary lightning mapper", "abstract": "Abstract During November 2018April 2019, an 11-station very high frequency (VHF) Lightning Mapping Array (LMA) was deployed to Cordoba Province, Argentina. The purpose of the LMA was validation of the Geostationary Lightning Mapper (GLM), but the deployment was coordinated with two field campaigns. The LMA observed 2.9 million flashes ( five sources) during 163 days, and level-1 (VHF locations), level-2 (flashes classified), and level-3 (gridded products) datasets have been made public. The networks performance allows scientifically useful analysis within 100 km when at least seven stations were active. Careful analysis beyond 100 km is also possible. The LMA dataset includes many examples of intense storms with extremely high flash rates (>1 s1), electrical discharges in overshooting tops (OTs), as well as anomalously charged thunderstorms with low-altitude lightning. The modal flash altitude was 10 km, but many flashes occurred at very high altitude (1520 km). There were also anomalous and stratiform flashes near 57 km in altitude. Most flashes were small (<50 km2 area). Comparisons with GLM on 14 and 20 December 2018 indicated that GLM most successfully detected larger flashes (i.e., more than 100 VHF sources), with detection efficiency (DE) up to 90%. However, GLM DE was reduced for flashes that were smaller or that occurred lower in the cloud (e.g., near 6-km altitude). GLM DE also was reduced during a period of OT electrical discharges. Overall, GLM DE was a strong function of thunderstorm evolution and the dominant characteristics of the lightning it produced.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019MS001916", "year": 2020, "title": "The Community Earth System Model Version 2 (CESM2)", "abstract": "An overview of the Community Earth System Model Version 2 (CESM2) is provided, including a discussion of the challenges encountered during its development and how they were addressed. In addition, an evaluation of a pair of CESM2 long preindustrial control and historical ensemble simulations is presented. These simulations were performed using the nominal 1\u00b0 horizontal resolution configuration of the coupled model with both the \"low-top\" (40 km, with limited chemistry) and \"high-top\" (130 km, with comprehensive chemistry) versions of the atmospheric component. CESM2 contains many substantial science and infrastructure improvements and new capabilities since its previous major release, CESM1, resulting in improved historical simulations in comparison to CESM1 and available observations. These include major reductions in low-latitude precipitation and shortwave cloud forcing biases; better representation of the Madden-Julian Oscillation; better El Ni\u00f1o-Southern Oscillation-related teleconnections; and a global land carbon accumulation trend that agrees well with observationally based estimates. Most tropospheric and surface features of the low- and high-top simulations are very similar to each other, so these improvements are present in both configurations. CESM2 has an equilibrium climate sensitivity of 5.1-5.3 \u00b0C, larger than in CESM1, primarily due to a combination of relatively small changes to cloud microphysics and boundary layer parameters. In contrast, CESM2's transient climate response of 1.9-2.0 \u00b0C is comparable to that of CESM1. The model outputs from these and many other simulations are available to the research community, and they represent CESM2's contributions to the Coupled Model Intercomparison Project Phase 6.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.2151/SOLA.2022-025", "year": 2022, "title": "Diurnal Variation of Surface Wind Divergence in the Maritime Continent Using ASCAT and SeaWinds Observations and ERA5 Reanalysis Data", "abstract": "This study investigates the diurnal variation of surface wind divergence in the seas of the Maritime Continent by using satellite scatterometer observations and atmospheric reanalysis data. This is the first study to demonstrate the distribution and seasonal variation of the diurnally varying surface winds in the Maritime Continent in terms of wind divergence. Wind divergence develops from the coasts of the islands toward the center of the seas and dominates during the afternoon and evening hours. Wind convergence dominates over the seas during the nighttime and morning hours. The offshore extensions of the wind divergence and convergence from the coast differ regionally and thus show the asymmetric patterns with respect to the center of the seas. In particular, strong wind divergence develops from the southern coasts of the Java Sea and the Arafura Sea to extend northward beyond the center of the seas. The diurnal amplitudes of wind divergence vary seasonally and reach a peak in September in most of the seas. The switching times between wind divergence and convergence are almost fixed throughout the year regardless of the monsoon reversal.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.OCEMOD.2021.101850", "year": 2021, "title": "Blending drifters and altimetric data to estimate surface currents: Application in the Levantine Mediterranean and objective validation with different data types", "abstract": "An improved estimation of the surface currents in the Levantine Basin of the Mediterranean sea is crucial for a wide range of applications, including pollutants transport and nutrients distribution. This estimation remains challenging due to the scarcity or shortcomings of various data types used for this purpose. In this paper, we present an objective validation of a variational assimilation algorithm that blends geostrophic velocities derived from altimetry, wind-induced velocities, and drifter positions, to continuously obtain velocity corrections. The assessment of the validation impact was based on available independent in-situ data (current meters, gliders, and independent drifters) and satellite ocean color images. In all cases, the improvement was shown either qualitatively (position of the eddies) or quantitatively.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JAG.2021.102307", "year": 2021, "title": "Combining simulated hyperspectral EnMAP and Landsat time series for forest aboveground biomass mapping", "abstract": "Forest aboveground biomass (AGB) is a critical measure of ecosystem structure and plays a key role in global carbon cycling. Due to its widespread availability, optical remotely sensed data are key for regional- and global-scale AGB assessment, and with the planned and recent launches of spaceborne imaging spectroscopy missions such as the Environmental Mapping and Analysis Program (EnMAP), understanding the benefit of added spectral information for AGB mapping is important. We used simulated EnMAP imagery derived from Airborne Visible InfraRed Imaging Spectrometer (AVIRIS) imagery acquired over Sonoma County, California, USA in combination with Landsat time series to map forest AGB. A Gaussian Process Regression model was implemented to estimate forest AGB from one- and two-date (April and June) EnMAP imagery. A lidar-based reference AGB map was used as base data for training and validation sample extraction. As a comparison, we used corresponding Landsat Best Available Pixel (BAP) composites as well as a year-long 16-day interpolated Landsat time series (TS) for 2013. EnMAP imagery was able to effectively map forest AGB, with the two-date model (RMSE = 97.5 Mg/ha) outperforming the two single date models. All EnMAP models outperformed the corresponding Landsat BAP models, the best of which was the two-date model (RMSE = 108.8 Mg/ha). The added temporal dimension of the Landsat time series resulted in the best Landsat-based AGB map (RMSE = 102.3 Mg/ha). Combining the two datasets further improved AGB mapping efforts, with 2-date EnMAP + 2013 Landsat TS providing the best overall AGB maps (RMSE = 86.0 Mg/ha). This study demonstrates not only the added value of hyperspectral imagery for forest AGB mapping, but also the possible synergies between hyperspectral and multispectral data sources and hence between spectrally and temporally dense information. It can be expected that with the next generation of spaceborne hyperspectral sensors, the combination of dense spectral and temporal data will work to further improve global efforts for mapping forest AGB from optical Earth observation data.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.118160", "year": 2021, "title": "Towards a regional dust modeling system in the central Middle East: Evaluation, uncertainties and recommendations", "abstract": "This study aims towards an accurate regional dust modeling system in the central Middle East area (CME), through the implementation of the state-of-art dust parameterizations. The modeling system consists of the natural emission model NEMO, the meteorological model WRF and the chemistry transport model CAMx. An extensive evaluation of 16 different configurations has been realized, incorporating all the combinations of the components utilized in the state-of-art dust modeling approaches, namely the drag partition, the sandblasting efficiency, the horizontal mass flux, as well two commonly used soil particle size distributions. Daily mean PM10 measurements in Doha, as well the satellite AOD products of MODIS have been used for the quantitative and the qualitative assessment of the simulations. Noteworthy, each of these assessments did not yield to the exact same ranking of the configurations (e.g. best five) but they assisted on identifying clear patterns. For example, a consistent overestimation of the daily mean PM10, when the MacKinnon's drag partition scheme is utilized, was found. On the other hand, the assessments led to best three performing configurations, with common components the Raupach's drag partition scheme and Alfaro and Gomes sandblasting efficiency. Although their overall performance is good, several issues were found i.e. on individual dust events and a mean underestimation during the studied period, ranging from 49 to 75 g/m3. One cause of this underestimation could be the aerodynamic entrainment, a mechanism usually neglected from the dust modeling approaches. Another cause could be missed regional and/or local sources or underestimation of their emission rates.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JHYDROL.2020.125186", "year": 2020, "title": "A unified framework of water balance models for monthly, annual, and mean annual timescales", "abstract": "At present, many conceptual water balance models have been proposed on monthly, annual, and mean annual timescales. With the increasing applications of these models, an emerging question is whether the water balance models on different timescales have some commonalities and can be integrated. To this end, this study established and applied a practical unified framework of water balance models that can be applied to different timescales. The framework was first developed on monthly timescale, where the water balance was captured by combining the abcd model and Budyko hypothesis with four parameters. Then, this framework was extended to annual and mean annual timescales under which certain parameters can be eliminated or assumed to be certain values. To be specific, on the annual timescale, the water balance was simulated by a Budyko-type model incorporating the water storage change; on the mean annual timescale the water balance was further simplified into a Budyko-type model which neglects the water storage change. Thus, all of the three typical water balance models on different timescales were unified to a general framework. The models were applied to 437 catchments in the contiguous United States with satisfying results achieved. Considering the water storage changes can improve the performance of annual water balance models in regions with clear interannual carrying water storage. Furthermore, the water balance models on different timescales share common supply and demand limits which is similar to Budyko hypothesis.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2018GL080976", "year": 2018, "title": "Lake level and surface topography measured with spaceborne GNSS\u2010reflectometry from CYGNSS mission: Example for the lake Qinghai", "abstract": "This paper demonstrates inland water altimetry of spaceborne Global Navigation Satellite System-Reflectometry (GNSS-R) using the Cyclone GNSS (CYGNSS) mission data. From 12 tracks of raw data overpassing the Lake Qinghai, the bistatic group delay and carrier phase delay are extracted from the quasi-specular GNSS reflections. The water levels derived from the group delay observations are consistent with the Cryosat-2 and in situ gauge measurements. The surface topography profiles from the phase delay measurements show good self-consistence along the coincident tracks. Decimeter-level surface height anomalies are resolved with the phase delay measurements, which can be associated with the accuracy degradation of the geoid model in this region. Systematic errors remain in both group delay and phase delay altimetry measurements, which are attributed to the receiver orbit errors and ionospheric correction residuals. These limitations can be eliminated in further GNSS-R missions dedicated to altimetry applications.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.RSE.2018.12.031", "year": 2019, "title": "Coupled estimation of 500 m and 8-day resolution global evapotranspiration and gross primary production in 2002\u20132017", "abstract": "Accurate quantification of terrestrial evapotranspiration (ET) is essential to understand the Earth's energy and water budgets under climate change. However, despite water and carbon cycle coupling, there are few diagnostic global evapotranspiration models that have complete carbon constraint on water flux run at a high spatial resolution. Here we estimate 8-day global ET and gross primary production (GPP) at 500 m resolution from July 2002 to December 2017 using a coupled diagnostic biophysical model (called PML-V2) that, built using Google Earth Engine, takes MODIS data (leaf area index, albedo, and emissivity) together with GLDAS meteorological forcing data as model inputs. PML-V2 is well calibrated against 8-day measurements at 95 widely-distributed flux towers for 10 plant functional types, indicated by Root Mean Square Error (RMSE) and Bias being 0.69 mm d1 and 1.8% for ET respectively, and being 1.99 g C m2 d1 and 4.2% for GPP. Compared to that performance, the cross-validation results are slightly degraded, with RMSE and Bias being 0.73 mm d1 and 3% for ET, and 2.13 g C m2 d1 and 3.3% for GPP, which indicates robust model performance. The PML-V2 products are noticeably better than most GPP and ET products that have a similar spatial resolution, and suitable for assessing the influence of carbon-induced impacts on ET. Our estimates show that global ET and GPP both significantly (p ", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ENVC.2021.100359", "year": 2021, "title": "A Topological Data Analysis approach for retrieving Local Climate Zones patterns in satellite data", "abstract": "In the context of geospatial studies, meaningful information may be hidden in the aspects of form and connectivity inscribed in the measurements. Therefore, here is proposed the use of H0 Persistent Homology (PH), a Topological Data Analysis tool to automatically summarize and quantify relevant spatial features in satellite data. With that aim, we extend the algebraic concepts of cubical complexes to the satellite data perspective and describe homology groups portrayal. As a proof by example, we present an inter-site comparison of Enhanced Vegetation Index from MODerate-resolution Imaging Spectroradiometer over fifteen regions worldwide. There, the Local Climate Zone (LCZ) framework is used to examine the outcomes of the PH filtration. Then, the features from every region that were encapsulated by the PH were compared against each other with the aid of the Bottleneck Distance metric. After that, it was performed a dimensionality reduction with a multi-dimensional scaling to build a 2-D geometry of the level of similarity among them. Thereby, the common aspects of the regions became explicit by their coordinates proximity in space. Then, with the use of the K-means algorithm, we were able to cluster those areas belonging to the same LCZ class. The results indicate that the proposed methods are robust to missing data in the satellite data and insensitive to a certain level of inhomogeneity in the spatial subsetting of data. Furthermore, the outcomes provide insights on several viable applications for future research.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1109/LGRS.2021.3058956", "year": 2022, "title": "Monthly Surface Elevation Changes of the Greenland Ice Sheet From ICESat-1, CryoSat-2, and ICESat-2 Altimetry Missions", "abstract": "The Greenland Ice Sheet (GrIS) mass balance shows significant variabilities over a range of time scales. As geodetic records lengthen over time, it becomes insufficient to characterize the temporal evolution of the ice sheet by using a best-fit linear trend over a given observation period. This study investigates the joint analysis of laser and radar satellite altimeter measurements for estimating GrIS surface elevation changes (SECs) with a 30-day resolution. We first apply a crossover analysis to assess the precisions of the surface elevations measured by ICESat-1/2 laser altimeters and CryoSat-2 radar altimeter over the GrIS, which are needed for assigning weights for each data set in the joint analysis. Then, based on a modified repeat-track approach, we analyze the surface elevation measurements of ICESat-1/2 and CryoSat-2 to produce monthly SEC estimates for the past two decades, together with their associated uncertainties. The multimission SEC estimates are further assessed by using IceBridge airborne laser measurements, showing differences with a median value of 12 cm 60 cm. The monthly SEC time series reveal important variations over a range of time scales across different parts of the GrIS and would facilitate the investigation of complex spatiotemporal patterns of GrIS changes.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-19-3307-2019", "year": 2019, "title": "Multi-satellite retrieval of single scattering albedo using the OMI\u2013MODIS algorithm", "abstract": "Abstract. Single scattering albedo (SSA) represents a unique identification of aerosol type and can be a determinant factor in the estimation of aerosol radiative forcing. However, SSA retrievals are highly uncertain due to cloud contamination and aerosol composition. The recent improvement in the SSA retrieval algorithm has combined the superior cloud-masking technique of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the higher sensitivity of the Ozone Monitoring Instrument (OMI) to aerosol absorption. The combined OMIMODIS algorithm has only been validated over a small spatial and temporal scale. The present study validates the algorithm over global oceans for the period from 2008 to 2012. The geographical heterogeneity in the aerosol type and concentration over the Atlantic Ocean, the Arabian Sea and the Bay of Bengal was useful to delineate the effect of aerosol type on the retrieval algorithm. We also noted that OMI overestimated SSA when absorbing aerosols were present closer to the surface. We attribute this overestimation to data discontinuity in the aerosol height climatology derived from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. OMI uses predefined aerosol heights over regions where CALIPSO climatology is not present, leading to the overestimation of SSA. The importance of aerosol height was also studied using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model. The results from the joint retrievals were validated using cruise-based measurements. It was seen that OMIMODIS SSA retrievals performed better than the OMI only retrieval over the Bay of Bengal during winter, when the aerosols are present closer to the surface. Discrepancy between satellite retrievals and cruise measurements was seen when elevated aerosols were present which might not have been detected by the cruise instruments.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JAFREARSCI.2021.104377", "year": 2021, "title": "Estimating gravity field and quasi-geoid in Cameroon (CGM20)", "abstract": "In this paper, the computation of the new gravimetric quasi-geoid of Cameroon based on some recent global geopotential models and a detailed Digital Terrain Model (DTM) of the area is presented. Besides gravity data supplied by the Bureau Gravimetrique International (BGI) new data have been collected by the National Institute of Cartography (NIC) of Cameroon and used in the computation. Three different quasi-geoid models have been obtained based on three different global models, namely GOCE-dir5, EGM2008 and XGM2019e_2159. The well-known remove-compute-restore technique has been applied and Fast Collocation has been used for estimating the residual quasi-geoid component from gridded gravity data. The comparisons with Global Navigation Satellite System/levelling (GNSS/levelling) data distributed over the Cameroon territory show that some improvements have been obtained either with respect to the global model solutions and to previous local estimates computed in the past.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.RSE.2020.112191", "year": 2021, "title": "Remotely sensed ensembles of the terrestrial water budget over major global river basins: An assessment of three closure techniques", "abstract": "Remote sensing is a useful tool for observing the water cycle. However, combining remote sensing products over any major river basin will result in a residual error in the overall water balance. Previous studies have either quantified this error without correcting it, or have merged observations together with land surface models (LSMs) to produce a single best estimate of the water balance. Here, we present a new approach in which combinations of remote sensing and in situ observations are constrained to enforce water balance closure. Rather than a single estimate, this produces an ensemble of unique water balance estimates intended to characterize uncertainty and to avoid biases implicit in LSMs. We evaluate three techniques of varying complexity to enforce water balance closure for individual ensemble members over 24 global basins from Oct. 2002 - Dec. 2014, resulting in as many as 60 realizations of the monthly water budget, contingent upon data availability. Compared with a published climate data record, the ensemble shows strong agreement for precipitation, evapotranspiration and changes in storage (R2: 0.910.95), with less agreement for streamflow (R2: 0.420.47), which may be indicative of LSM biases in the climate data record. Water balance residual errors resulting from combinations of raw products vary significantly (p ", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019JD030911", "year": 2020, "title": "Fifty Years of Research on the MaddenJulian Oscillation: Recent Progress, Challenges, and Perspectives", "abstract": "Since its discovery in the early 1970s, the crucial role of the Madden-Julian Oscillation (MJO) in the global hydrological cycle and its tremendous influence on high-impact climate and weather extremes have been well recognized. The MJO also serves as a primary source of predictability for global Earth system variability on subseasonal time scales. The MJO remains poorly represented in our state-of-the-art climate and weather forecasting models, however. Moreover, despite the advances made in recent decades, theories for the MJO still disagree at a fundamental level. The problems of understanding and modeling the MJO have attracted significant interest from the research community. As a part of the AGU's Centennial collection, this article provides a review of recent progress, particularly over the last decade, in observational, modeling, and theoretical study of the MJO. A brief outlook for near-future MJO research directions is also provided.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/2150704X.2019.1602790", "year": 2019, "title": "Statistical and visual quality assessment of nearly-global and continental digital elevation models of Trentino, Italy", "abstract": "Nearly-global digital elevation models (DEMs) Shuttle Radar Topography Mission DEM (SRTM1 DEM), Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM), and Advanced Land Observing Satellite World 3D digital surface model (AW3D30 DSM) are widely used in geosciences. A nearly-continental European DEM (EU-DEM) is also publicly available. We assess statistical accuracy and artefact occurrence of the latest versions of these models for Trentino, Italian Alps. We used a set of 111 geodetic network points and a lidar-based reference DEM. Statistically, AW3D30 DSM has the highest accuracy, while EU-DEM is marked by the worst characteristics. To visualize the spatial distribution of errors, we calculated residuals between the reference and validated DEMs. Voids abound in SRTM1 DEM that makes problematic its application in the Alpine region. Randomly distributed, grain-like artefacts are common for ASTER GDEM. AW3D30 DSM includes artefacts caused by to the Gibbs phenomenon. Retaining defects of SRTM1 DEM and ASTER GDEM, EU-DEM has artefacts caused by its hydrological correction. Usual statistical evaluation of DEM accuracy is not capable to describe completely DEM quality. A robust spatial analysis, including interactive visual inspection, should be adopted for a quality control of DEMs.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-17-11541-2017", "year": 2017, "title": "Reanalysis comparisons of upper troposphericlower stratospheric jets and multiple tropopauses", "abstract": "Abstract. The representation of upper troposphericlower stratospheric (UTLS) jet and tropopause characteristics is compared in five modern high-resolution reanalyses for 1980 through 2014. Climatologies of upper tropospheric jet, subvortex jet (the lowermost part of the stratospheric vortex), and multiple tropopause frequency distributions in MERRA (Modern-Era Retrospective analysis for Research and Applications), ERA-I (ERA-Interim; the European Centre for Medium-Range Weather Forecasts, ECMWF, interim reanalysis), JRA-55 (the Japanese 55-year Reanalysis), and CFSR (the Climate Forecast System Reanalysis) are compared with those in MERRA-2. Differences between alternate products from individual reanalysis systems are assessed; in particular, a comparison of CFSR data on model and pressure levels highlights the importance of vertical grid spacing. Most of the differences in distributions of UTLS jets and multiple tropopauses are consistent with the differences in assimilation model grids and resolution for example, ERA-I (with coarsest native horizontal resolution) typically shows a significant low bias in upper tropospheric jets with respect to MERRA-2, and JRA-55 (the Japanese 55-year Reanalysis) a more modest one, while CFSR (with finest native horizontal resolution) shows a high bias with respect to MERRA-2 in both upper tropospheric jets and multiple tropopauses. Vertical temperature structure and grid spacing are especially important for multiple tropopause characterizations. Substantial differences between MERRA and MERRA-2 are seen in mid- to high-latitude Southern Hemisphere (SH) winter upper tropospheric jets and multiple tropopauses as well as in the upper tropospheric jets associated with tropical circulations during the solstice seasons; some of the largest differences from the other reanalyses are seen in the same times and places. Very good qualitative agreement among the reanalyses is seen between the large-scale climatological features in UTLS jet and multiple tropopause distributions. Quantitative differences may, however, have important consequences for transport and variability studies. Our results highlight the importance of considering reanalyses differences in UTLS studies, especially in relation to resolution and model grids; this is particularly critical when using high-resolution reanalyses as an observational reference for evaluating global chemistryclimate models.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5334/DSJ-2017-004", "year": 2017, "title": "Enhancing interoperability and capabilities of earth science data using the Observations Data Model 2 (ODM2)", "abstract": "Earth Science researchers require access to integrated, cross-disciplinary data in order to answer critical research questions. Partially due to these science drivers, it is common for disciplinary data systems to expand from their original scope in order to accommodate collaborative research. The result is multiple disparate databases with overlapping but incompatible data. In order to enable more complete data integration and analysis, the Observations Data Model Version 2 (ODM2) was developed to be a general information model, with one of its major goals to integrate data collected by in situ sensors with those by ex-situ analyses of field specimens. Four use cases with different science drivers and disciplines have adopted ODM2 because of benefits to their users. The disciplines behind the four cases are diverse hydrology, rock geochemistry, soil geochemistry, and biogeochemistry. For each case, we outline the benefits, challenges, and rationale for adopting ODM2. In each case, the decision to implement ODM2 was made to increase interoperability and expand data and metadata capabilities. One of the common benefits was the ability to use the flexible handling and comprehensive description of specimens and data collection sites in ODM2s sampling feature concept. We also summarize best practices for implementing ODM2 based on the experience of these initial adopters. The descriptions here should help other potential adopters of ODM2 implement their own instances or to modify ODM2 to suit their needs.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/JTECH-D-14-00080.1", "year": 2015, "title": "An improved near-surface specific humidity and air temperature climatology for the SSM/I satellite period", "abstract": "Abstract A near-surface specific humidity (Qa) and air temperature (Ta) climatology on daily and 0.25 grids was constructed by the objectively analyzed airsea fluxes (OAFlux) project by objectively merging two recent satellite-derived high-resolution analyses, the OAFlux existing 1 analysis, and atmospheric reanalyses. The two satellite products include the multi-instrument microwave regression (MIMR) Qa and Ta analysis and the Goddard Satellite-Based Surface Turbulent Fluxes, version 3 (GSSTF3), Qa analysis. This study assesses the degree of improvement made by OAFlux using buoy time series measurements at 137 locations and a global empirical orthogonal function (EOF) analysis. There are a total of 130 855 collocated daily values for Qa and 283 012 collocated daily values for Ta in the buoy evaluation. It is found that OAFlux Qa has a mean difference close to 0 and a root-mean-square (RMS) difference of 0.73 g kg1, and Ta has a mean difference of 0.03C and an RMS difference of 0.45C. OAFlux shows no major systematic bias with respect to buoy measurements over all buoy locations except for the vicinity of the Gulf Stream boundary current, where the RMS difference exceeds 1.8C in Ta and 1.2 g kg1 in Qa. The buoy evaluation indicates that OAFlux represents an improvement over MIMR and GSSTF3. The global EOF-based intercomparison analysis indicates that OAFlux has a similar spatialtemporal variability pattern with that of three atmospheric reanalyses including MERRA, NCEP-1, and ERA-Interim, but that it differs from GSSTF3 and the Climate Forecast System Reanalysis (CFSR).", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ESSD-12-647-2020", "year": 2020, "title": "A Fundamental Climate Data Record of SMMR, SSM/I, and SSMIS brightness temperatures", "abstract": "Abstract. The Fundamental Climate Data Record (FCDR) of Microwave Imager Radiances from the Satellite Application Facility on Climate Monitoring (CM SAF)\ncomprises inter-calibrated and homogenized brightness temperatures from the Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor\nMicrowave/Imager (SSM/I), and the Special Sensor Microwave Imager/Sounder SSMIS radiometers. It covers the time period from October 1978 to\nDecember 2015 including all available data from the SMMR radiometer aboard Nimbus-7 and all SSM/I and SSMIS radiometers aboard the Defense\nMeteorological Satellite Program (DMSP) platforms. SMMR, SSM/I, and SSMIS data are used for a variety of applications, such as analyses of the\nhydrological cycle, remote sensing of sea ice, or as input into reanalysis projects. The improved homogenization and inter-calibration procedure\nensures the long-term stability of the FCDR for climate-related applications. All available raw data records from different sources have been\nreprocessed to a common standard, starting with the calibration of the raw Earth counts, to ensure a completely homogenized data record. The data\nprocessing accounts for several known issues with the instruments and corrects calibration anomalies due to along-scan inhomogeneity, moonlight\nintrusions, sunlight intrusions, and emissive reflector. Corrections for SMMR are limited because the SMMR raw data records were not available.\nFurthermore, the inter-calibration model incorporates a scene dependent inter-satellite bias correction and a non-linearity correction in the\ninstrument calibration. The data files contain all available original sensor data (SMMR: Pathfinder level 1b) and metadata to provide a completely\ntraceable climate data record. Inter-calibration and Earth incidence angle normalization offsets are available as additional layers within the data\nfiles in order to keep this information transparent to the users. The data record is complemented with noise-equivalent temperatures (NeT),\nquality flags, surface types, and Earth incidence angles. The FCDR together with its full documentation, including evaluation results, is freely\navailable at: https://doi.org/10.5676/EUM_SAF_CM/FCDR_MWI/V003 (Fennig et al., 2017).", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-8-4561-2015", "year": 2015, "title": "Quality assessment and improvement of the EUMETSAT Meteosat surface albedo climate data record", "abstract": "Abstract. Surface albedo has been identified as an important parameter for understanding and quantifying the Earth's radiation budget. EUMETSAT generated the Meteosat Surface Albedo (MSA) Climate Data Record (CDR) currently comprising up to 24 years (19822006) of continuous surface albedo coverage for large areas of the Earth. This CDR has been created within the Sustained, Coordinated Processing of Environmental Satellite Data for Climate Monitoring (SCOPE-CM) framework. The long-term consistency of the MSA CDR is high and meets the Global Climate Observing System (GCOS) stability requirements for desert reference sites. The limitation in quality due to non-removed clouds by the embedded cloud screening procedure is the most relevant weakness in the retrieval process. A twofold strategy is applied to efficiently improve the cloud detection and removal. The first step consists of the application of a robust and reliable cloud mask, taking advantage of the information contained in the measurements of the infrared and visible bands. Due to the limited information available from old radiometers, some clouds can still remain undetected. A second step relies on a post-processing analysis of the albedo seasonal variation together with the usage of a background albedo map in order to detect and screen out such outliers. The usage of a reliable cloud mask has a double effect. It enhances the number of high-quality retrievals for tropical forest areas sensed under low view angles and removes the most frequently unrealistic retrievals on similar surfaces sensed under high view angles. As expected, the usage of a cloud mask has a negligible impact on desert areas where clear conditions dominate. The exploitation of the albedo seasonal variation for cloud removal has good potentialities but it needs to be carefully addressed. Nevertheless it is shown that the inclusion of cloud masking and removal strategy is a key point for the generation of the next MSA CDR release.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS12233930", "year": 2020, "title": "Variational Retrievals of High Winds Using Uncalibrated CyGNSS", "abstract": "This study presents a new retrieval approach for obtaining wind speeds from CyGNSS level-1 observables. Unlike other existing approaches, (1) this one is a variational technique that is based on a physical forward model, (2) it uses uncalibrated bin raw counts observables, (3) the geophysical information content comes from only one pixel of the broader delay-Doppler map, finest achievable resolution in level-1 products over the sea, and (4) calibrates them against track-wise polynomial adjustments to a background numerical weather prediction model. Through comparisons with the background model, other spaceborne sensors (SMAP, SMOS, ASCAT-A/B), and CyGNSS wind retrievals by other organizations, the study shows that this approach has skills to infer wind speeds, including hurricane force winds. For example, the Pearsons correlation coefficient between these CyGNSS retrievals and ERA5 is 0.884, 0.832 with NOAA CyGNSS results, and 0.831 with respect to SMAP co-located measurements. Furthermore, the variational retrieval algorithm is a simplified version of the more general equations that are used in data assimilation, and the calibration scheme could also be integrated in the assimilation process. Therefore, this approach is also a good tool for analyzing the potential performance of ingesting uncalibrated level-1 single-pixel observables into NWP.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/2016GL068462", "year": 2016, "title": "Skill improvement of dynamical seasonal Arctic sea ice forecasts", "abstract": "We explore the error and improve the skill of the outcome from dynamical seasonal Arctic sea ice reforecasts using different bias correction and ensemble calibration methods. These reforecasts consist of a five-member ensemble from 1979 to 2012 using the general circulation model EC-Earth. The raw model reforecasts show large biases in Arctic sea ice area, mainly due to a differently simulated seasonal cycle and long term trend compared to observations. This translates very quickly (1-3 months) into large biases. We find that (heteroscedastic) extended logistic regressions are viable ensemble calibration methods, as the forecast skill is improved compared to standard bias correction methods. Analysis of regional skill of Arctic sea ice shows that the Northeast Passage and the Kara and Barents Sea are most predictable. These results show the importance of reducing model error and the potential for ensemble calibration in improving skill of seasonal forecasts of Arctic sea ice.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS14030497", "year": 2022, "title": "Ancillary Data Uncertainties within the SeaDAS Uncertainty Budget for Ocean Colour Retrievals", "abstract": "Atmospheric corrections introduce uncertainties in bottom-of-atmosphere Ocean Colour (OC) products. In this paper, we analyse the uncertainty budget of the SeaDAS atmospheric correction algorithm. A metrological approach is followed, where each of the error sources are identified in an uncertainty tree diagram and briefly discussed. Atmospheric correction algorithms depend on ancillary variables (such as meteorological properties and column densities of gases), yet the uncertainties in these variables were not studied previously in detail. To analyse these uncertainties for the first time, the spread in the ERA5 ensemble is used as an estimate for the uncertainty in the ancillary data, which is then propagated to uncertainties in remote sensing reflectances using a Monte Carlo approach and the SeaDAS atmospheric correction algorithm. In an example data set, wind speed and relative humidity are found to be the main contributors (among the ancillary parameters) to the remote sensing reflectance uncertainties.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-15-4063-2022", "year": 2022, "title": "On the influence of underlying elevation data on Sentinel-5 Precursor TROPOMI satellite methane retrievals over Greenland", "abstract": "Abstract. The Sentinel-5 Precursor (S5P) mission was launched on October 2017 and has since provided data with high spatio-temporal resolution using its remote sensing instrument, the TROPOspheric Monitoring Instrument (TROPOMI). The latter is a nadir viewing passive grating imaging spectrometer. The mathematical inversion of the TROPOMI data yields retrievals of different trace gas and aerosol data products. The column-averaged dry-air mole fraction of methane (XCH4) is the product of interest to this study. The daily global coverage of the atmospheric methane mole fraction data enables the analysis of the methane distribution and variation on large scales and also to estimate surface emissions. The spatio-temporal high-resolution satellite data are potentially particularly valuable in remote regions, such as the Arctic, where few ground stations and in situ measurements are available. In addition to the operational Copernicus S5P total-column-averaged dry-air mole fraction methane data product developed by SRON, the scientific TROPOMI/WFMD algorithm data product v1.5 (WFMD product) was generated at the Institute of Environmental Physics at the University of Bremen. In this study we focus on the assessment of both S5P XCH4 data products over Greenland and find that spatial maps of both products show distinct features along the coastlines. Anomalies up to and exceeding 100 ppb are observed and stand out in comparison to the otherwise smooth changes in the methane distribution. These features are more pronounced for the operational product compared to the WFMD product. The spatial patterns correlate with the difference between the GMTED2010 digital elevation model (DEM) used in the retrievals and a more recent topography dataset, indicating that inaccuracies in the assumed surface elevation are the origin of the observed features. These correlations are stronger for the WFMD product. In order to evaluate the impact of the topography dataset on the retrieval we reprocess the WFMD product with updated elevation data. We find that a significant reduction of the localized features when GMTED2010 is replaced by recent topography data over Greenland based on ICESat-2 data. This study shows the importance of the chosen topography data for retrieved dry-air mole fractions. The use of a DEM that is as accurate and as up to date as possible is advised for all S5P data products as well as for future missions which rely on a DEM as input data. A modification based on this study is planned to be introduced in the next version of the WFMD data product.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019JD031400", "year": 2020, "title": "Evaluation of OCO2 X Variability at Local and Synoptic Scales using Lidar and In Situ Observations from the ACTAmerica Campaigns", "abstract": "With nearly 1 million observations of column-mean carbon dioxide concentration (XCO2) per day, the Orbiting Carbon Observatory 2 (OCO-2) presents exciting possibilities for monitoring the global carbon cycle, including the detection of subcontinental column CO2 variations. While the OCO-2 data set has been shown to achieve target precision and accuracy on a single-sounding level, the validation of XCO2 spatial gradients on subcontinental scales remains challenging. In this work, we investigate the use of an integrated path differential absorption (IPDA) lidar for evaluation of OCO-2 observations via NASA's Atmospheric Carbon and Transport (ACT)-America project. The project has completed eight clear-sky underflights of OCO-2 with the Multifunctional Fiber Laser Lidar (MFLL)\u2014along with a suite of in situ instruments\u2014giving a precisely colocated, high-resolution validation data set spanning nearly 3,800 km across four seasons. We explore the challenges and opportunities involved in comparing the MFLL and OCO-2 XCO2 data sets and evaluate their agreement on synoptic and local scales. We find that OCO-2 synoptic-scale gradients generally agree with those derived from the lidar, typically to \u00b10.1 ppm per degree latitude for gradients ranging in strength from 0 to 1 ppm per degree latitude. CO2 reanalysis products also typically agree to \u00b10.25 ppm per degree when compared with an in situ-informed CO2 \"curtain.\" Real XCO2 features at local scales, however, remain challenging to observe and validate from space, with correlation coefficients typically below 0.35 between OCO-2 and the MFLL. Even so, ACT-America data have helped investigate interesting local XCO2 patterns and identify systematic spurious cloud-related features in the OCO-2 data set.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-15-605-2022", "year": 2022, "title": "Differential absorption lidar measurements of water vapor by the High Altitude Lidar Observatory (HALO): retrieval framework and first results", "abstract": "Abstract. Airborne differential absorption lidar (DIAL) offers a uniquely capable solution to the problem of measuring water vapor (WV) with high precision, accuracy, and resolution throughout the troposphere and lower stratosphere. The High Altitude Lidar Observatory (HALO) airborne WV DIAL was recently developed at NASA Langley Research Center and was first deployed in 2019. It uses four wavelengths near 935 nm to achieve sensitivity over a wide dynamic range and simultaneously employs 1064 nm backscatter and 532 nm high-spectral-resolution lidar (HSRL) measurements for aerosol and cloud profiling. A key component of the WV retrieval framework is flexibly trading resolution for precision to achieve optimal datasets for scientific objectives across scales. An approach to retrieving WV in the lowest few hundred meters of the atmosphere using the strong surface return signal is also presented. The five maiden flights of the HALO WV DIAL spanned the tropics through midlatitudes with a wide range of atmospheric conditions, but opportunities for validation were sparse. Comparisons to dropsonde WV profiles were qualitatively in good agreement, though statistical analysis was impossible due to systematic error in the dropsonde measurements. Comparison of HALO to in situ WV measurements aboard the aircraft showed no substantial bias across 3 orders of magnitude, despite variance (R2=0.66) that may be largely attributed to spatiotemporal variability. Precipitable water vapor measurements from the spaceborne sounders AIRS and IASI compared very well to HALO with R2>0.96 over ocean.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS13183581", "year": 2021, "title": "Digital elevation models: Terminology and definitions", "abstract": "Digital elevation models (DEMs) provide fundamental depictions of the three-dimensional shape of the Earths surface and are useful to a wide range of disciplines. Ideally, DEMs record the interface between the atmosphere and the lithosphere using a discrete two-dimensional grid, with complexities introduced by the intervening hydrosphere, cryosphere, biosphere, and anthroposphere. The treatment of DEM surfaces, affected by these intervening spheres, depends on their intended use, and the characteristics of the sensors that were used to create them. DEM is a general term, and more specific terms such as digital surface model (DSM) or digital terrain model (DTM) record the treatment of the intermediate surfaces. Several global DEMs generated with optical (visible and near-infrared) sensors and synthetic aperture radar (SAR), as well as single/multi-beam sonars and products of satellite altimetry, share the common characteristic of a georectified, gridded storage structure. Nevertheless, not all DEMs share the same vertical datum, not all use the same convention for the area on the ground represented by each pixel in the DEM, and some of them have variable data spacings depending on the latitude. This paper highlights the importance of knowing, understanding and reflecting on the sensor and DEM characteristics and consolidates terminology and definitions of key concepts to facilitate a common understanding among the growing community of DEM users, who do not necessarily share the same background.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.GLOENVCHA.2021.102291", "year": 2021, "title": "Scenario archetypes reveal risks and opportunities for global mountain futures", "abstract": "Mountain social-ecological systems (MtSES) are transforming rapidly due to changes in multiple environmental and socioeconomic drivers. However, the complexity and diversity of MtSES present challenges for local communities, researchers and decision makers seeking to anticipate change and promote action towards sustainable MtSES. Participatory scenario planning can reveal potential futures and their interacting dynamics, while archetype analysis aggregates insights from site-based scenarios. We combined a systematic review of the global MtSES participatory scenarios literature and archetype analysis to identify emergent MtSES archetypal configurations. An initial sample of 1983 rendered 42 articles that contained 142 scenarios within which were 852 futures states. From these future states within the scenarios, we identified 59 desirable and undesirable futures that were common across studies. These common futures were grouped into four clusters that correlated significantly with three social-ecological factors (GDP per capita, income inequality, and mean annual temperature). Using these clusters and their associated significant factors, we derived four MtSES scenario archetypal configurations characterized by similar key adaptation strategies, assumptions, risks, and uncertainties. We called these archetypes: (1) revitalization through effective institutions and tourism; (2) local innovations in smallholder farming and forestry; (3) upland depopulation and increased risk of hazards; and (4) regulated economic and ecological prosperity. Results indicate risks to be mitigated, including biodiversity loss, ecosystem degradation, cultural heritage change, loss of connection to the land, weak leadership, market collapse, upland depopulation, increased landslides, avalanches, mudflows and rock falls, as well as climate variability and change. Transformative opportunities lie in adaptive biodiversity conservation, income diversification, adaptation to market fluxes, improving transport and irrigation infrastructure, high quality tourism and preserving traditional knowledge. Despite the uncertainties arising from global environmental changes, these archetypes support better targeting of evidence-informed actions across scales and sectors in MtSES.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/W10070901", "year": 2018, "title": "Performance assessment of MOD16 in evapotranspiration evaluation in Northwestern Mexico", "abstract": "Evapotranspiration (ET) is the second largest component of the water cycle in arid and semiarid environments, and, in fact, more than 60% of the precipitation on earth is returned to the atmosphere through it. MOD16 represents an operational source of ET estimates with adequate spatial resolution for several applications, such as water resources planning, at a regional scale. However, the use of these estimates in routine applications will require MOD16 evaluation and validation using accurate ground-based measurements. The main objective of this study was to evaluate the performance of the MOD16A2 product by comparing it with eddy covariance (EC) systems. Additional objectives were the analysis of the limitations, uncertainties, and possible improvements of the MOD16-estimated ET. The EC measurements were acquired for five sites and for a variety of land covers in northwestern Mexico. The indicators used for the comparison were: root mean square error (RMSE), bias (BIAS), concordance index (d), and determination coefficient (R2) of the correlation, comparing measured and modelled ET. The best performance was observed in Rayon (RMSE = 0.77 mmday1, BIAS = 0.46 mmday1, d = 0.88, and R2 = 0.86); El Mogor and La Paz showed errors and coefficients of determination comparable to each other (RMSE = 0.39 mmday1, BIAS = 0.04 mmday1, R2 = 0.46 and RMSE = 0.42 mmday1, BIAS = 0.18 mmday1, R2 = 0.45, respectively). In most cases, MOD16 underestimated the ET values.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01490419.2017.1333549", "year": 2017, "title": "Extension of satellite Altimetry Jason-2 sea level anomalies towards the red sea coast using polynomial harmonic techniques", "abstract": "Satellite altimetry data are facing big challenges near the coasts. These challenges arise due to the fundamental difficulties of correction and land contamination in the foot print, which result in rejection of these data near the coast. Several studies have been carried out to extend these data towards the coast. Over the Red Sea, altimetry data consist of gaps, which extend to about 3050 km from the coast. Two methods are used for processing and extending Jason-2 satellite altimetry sea level anomalies (SLAs) towards the Red Sea coast; Fourier Series Model (FSM), and the polynomial sum of sine model (SSM). FSM model technique uses Fourier series and statistical analysis reflects strong relationship with both the observation and AVISO data, with strong and positive correlation. The second prediction technique, SSM model, depends on the polynomial sum of sine, and does not reflect any relationship with the observations and AVISO data close to the coast and the correlation coefficient (CC) is weak and negative. The FSM model output results in SLA data significantly better and more accurate than the SSM model output.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-11-4273-2018", "year": 2018, "title": "Parameterizing cloud top effective radii from satellite retrieved values, accounting for vertical photon transport: quantification and correction of the resulting bias in droplet concentration and liquid water path retrievals", "abstract": "Abstract. Droplet concentration (Nd) and liquid water path (LWP) retrievals from passive satellite retrievals of cloud optical depth () and effective radius (re) usually assume the model of an idealized cloud in which the liquid water content (LWC) increases linearly between cloud base and cloud top (i.e. at a fixed fraction of the adiabatic LWC). Generally it is assumed that the retrieved re value is that at the top of the cloud. In reality, barring re retrieval biases due to cloud heterogeneity, the retrieved re is representative of smaller values that occur lower down in the cloud due to the vertical penetration of photons at the shortwave-infrared wavelengths used to retrieve re. This inconsistency will cause an overestimate of Nd and an underestimate of LWP (referred to here as the penetration depth bias), which this paper quantifies via a parameterization of the cloud top re as a function of the retrieved re and . Here we estimate the relative re underestimate for a range of idealized modelled adiabatic clouds using bispectral retrievals and plane-parallel radiative transfer. We find a tight relationship between gre=recloud top/reretrieved and and that a 1-D relationship approximates the modelled data well. Using this relationship we find that gre values and hence Nd and LWP biases are higher for the 2.1 m channel re retrieval (re2.1) compared to the 3.7 m one (re3.7). The theoretical bias in the retrieved Nd is very large for optically thin clouds, but rapidly reduces as cloud thickness increases. However, it remains above 20 % for <19.8 and <7.7 for re2.1 and re3.7, respectively. We also provide a parameterization of penetration depth in terms of the optical depth below cloud top (d) for which the retrieved re is likely to be representative. The magnitude of the Nd and LWP biases for climatological data sets is estimated globally using 1 year of daily MODIS (MODerate Imaging Spectroradiometer) data. Screening criteria are applied that are consistent with those required to help ensure accurate Nd and LWP retrievals. The results show that the SE Atlantic, SE Pacific and Californian stratocumulus regions produce fairly large overestimates due to the penetration depth bias with mean biases of 3235 % for re2.1 and 1517 % for re3.7. For the other stratocumulus regions examined the errors are smaller (2428 % for re2.1 and 1012 % for re3.7). Significant time variability in the percentage errors is also found with regional mean standard deviations of 1937 % of the regional mean percentage error for re2.1 and 3256 % for re3.7. This shows that it is important to apply a daily correction to Nd for the penetration depth error rather than a timemean correction when examining daily data. We also examine the seasonal variation of the bias and find that the biases in the SE Atlantic, SE Pacific and Californian stratocumulus regions exhibit the most seasonality, with the largest errors occurring in the December, January and February (DJF) season. LWP biases are smaller in magnitude than those for Nd (8 to 11 % for re2.1 and 3.6 to 6.1 % for re3.7). In reality, and especially for more heterogeneous clouds, the vertical penetration error will be combined with a number of other errors that affect both the re and , which are potentially larger and may compensate or enhance the bias due to vertical penetration depth. Therefore caution is required when applying the bias corrections; we suggest that they are only used for more homogeneous clouds.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1609/AAAI.V34I01.5379", "year": 2020, "title": "Lightweight and robust representation of economic scales from satellite imagery", "abstract": "Satellite imagery has long been an attractive data source providing a wealth of information regarding human-inhabited areas. While high-resolution satellite images are rapidly becoming available, limited studies have focused on how to extract meaningful information regarding human habitation patterns and economic scales from such data. We present READ, a new approach for obtaining essential spatial representation for any given district from high-resolution satellite imagery based on deep neural networks. Our method combines transfer learning and embedded statistics to efficiently learn the critical spatial characteristics of arbitrary size areas and represent such characteristics in a fixed-length vector with minimal information loss. Even with a small set of labels, READ can distinguish subtle differences between rural and urban areas and infer the degree of urbanization. An extensive evaluation demonstrates that the model outperforms state-of-the-art models in predicting economic scales, such as the population density in South Korea (R2=0.9617), and shows a high use potential in developing countries where district-level economic scales are unknown.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1088/1748-9326/AC4D4F", "year": 2022, "title": "A 30 m global map of elevation with forests and buildings removed", "abstract": "Abstract\r\n Elevation data are fundamental to many applications, especially in geosciences. The latest global elevation data contains forest and building artifacts that limit its usefulness for applications that require precise terrain heights, in particular flood simulation. Here, we use machine learning to remove buildings and forests from the Copernicus Digital Elevation Model to produce, for the first time, a global map of elevation with buildings and forests removed at 1 arc second (30 m) grid spacing. We train our correction algorithm on a unique set of reference elevation data from 12 countries, covering a wide range of climate zones and urban extents. Hence, this approach has much wider applicability compared to previous DEMs trained on data from a single country. Our method reduces mean absolute vertical error in built-up areas from 1.61 to 1.12 m, and in forests from 5.15 to 2.88 m. The new elevation map is more accurate than existing global elevation maps and will strengthen applications and models where high quality global terrain information is required.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/SD.1647", "year": 2017, "title": "The Imperatives of Sustainable Development", "abstract": "AbstractThe United Nations sustainable development goals are under fire. By attempting to cover all that is good and desirable in society, these targets have ended up as vague, weak, or meaningless. We suggest a model for sustainable development based on three moral imperatives: satisfying human needs, ensuring social equity, and respecting environmental limits. The model reflects Our Common Future's central message, moral imperatives laid out in philosophical texts on needs and equity, and recent scientific insights on environmental limits. The model is in conflict with the popular threepillar model of sustainable development, which seeks to balance social, environmental, and economic targets. Rather, we argue that sustainable development constitutes a set of constraints on human behaviour, including constraints on economic activity. By identifying indicators, and thresholds, we illustrate that different regions or groups of countries face different challenges. Copyright 2016 John Wiley & Sons, Ltd and ERP Environment", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/GMD-13-1999-2020", "year": 2020, "title": "The first Met Office Unified ModelJULES Regional Atmosphere and Land configuration, RAL1", "abstract": "Abstract. In this paper we define the first Regional Atmosphere and Land (RAL) science configuration for kilometre-scale modelling using the Unified Model (UM) as the basis for the atmosphere and the Joint UK Land Environment Simulator (JULES) for the land. RAL1 defines the science configuration of the dynamics and physics schemes of the atmosphere and land. This configuration will provide a model baseline for any future weather or climate model developments to be described against, and it is the intention that from this point forward significant changes to the system will be documented in the literature. This reproduces the process used for global configurations of the UM, which was first documented as a science configuration in 2011. While it is our goal to have a single defined configuration of the model that performs effectively in all regions, this has not yet been possible. Currently we define two sub-releases, one for mid-latitudes (RAL1-M) and one for tropical regions (RAL1-T). The differences between RAL1-M and RAL1-T are documented, and where appropriate we define how the model configuration relates to the corresponding configuration of the global forecasting model.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1111/RSP3.12441", "year": 2021, "title": "Nighttimelights satellite imagery reveals hotspots of second home mobility in rural Russia (a case study of Yaroslavl Oblast)", "abstract": "AbstractSecond home mobility is a wellknown phenomenon in many countries, but is widely prominent in Russia, where millions of city dwellers move to rural areas during the summertime. Combating longterm economic decline and depopulation, second home mobility creates a promising opportunity to revitalize the countryside. While this phenomenon is largely neglected by official statistics, we suggest using satellite imagery of nighttime lights to investigate its spatial and temporal patterns. We did this with the example of Yaroslavl Oblast in Russia. This region neighbors the Moscow Capital Region. It experiences a significant inflow of second home residents. By tracking the seasonal pixelwise changes of nighttime light radiance in monthly composites of satellite imagery from 2015 to 2019, we located hotspots of second homes and factors determining their spatial spread in rural areas. The results were evaluated with field research. Our results confirmed earlier conclusions that second homes locations in rural areas are largely determined by their proximity to Moscow, natural conditions, and transport accessibility. City dwellers often choose small and even fully abandoned villages for their second homes, which stresses the important role of second home mobility in preserving cultural landscapes. The proposed data and methods are limited by missing data for the northern regions during summer months and are more suitable for areas beyond the urban fringe where nighttimelights data are not biased by the overglow of large cities.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ISPRSJPRS.2020.01.011", "year": 2020, "title": "All-sky longwave downward radiation from satellite measurements: General parameterizations based on LST, column water vapor and cloud top temperature", "abstract": "Remotely sensed surface longwave downward radiation (LWDR) plays an essential role in studying the surface energy budget and greenhouse effect. Most existing satellite-based methods or products depend on variables that are not readily available from space such as, liquid water path, air temperature, vapor pressure and/or cloud-base temperature etc., which seriously restrict the wide applications of satellite data. In this paper, new nonlinear parameterizations and a machine learning-based model for deriving all-sky LWDR are proposed based only on land surface temperature (LST), column water vapor and cloud-top temperature (CTT), that are relatively readily available day and night for most satellite missions. It is the first time to incorporate the CTT in the parameterizations for estimating LWDR under the cloudy-sky conditions. The results reveal that the new models work well and can derive all-sky global LWDR with reasonable accuracies (RMSE <23 W/m2, bias <2.0 W/m2). The convenience of input data makes the new models easy to use, and thus will definitely expand the applicability of remotely sensed measurements in radiation budget fields and many land applications.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.AGRFORMET.2021.108806", "year": 2022, "title": "Evaluation of evapotranspiration estimation under cloud impacts over", "abstract": "Evapotranspiration (ET) is an important component of the hydrological cycle and energy balance in a land-atmosphere system. Satellite remote sensing has been widely used to estimate regional and global ET, but most previous methods depend on optical measurements that are limited to cloud-free conditions. This makes ET estimation challenging under cloudy sky. Currently, evaluations of satellite ET estimation under various cloud conditions remain lacking at the regional scale. Owing to the ability to penetrate clouds, satellite passive microwave measurements are powerful tools for retrieving ET under clouds. This study evaluated a satellite microwave-based daily ET method under all sky conditions over the part of China between 18\u00b0N and 50\u00b0N from 2003 to 2010, using microwave emissivity difference vegetation index (EDVI) as the proxy of vegetation water content (VWC). Validations using the surface water balance method found that the estimated ET (EDVI-ET) had an overall small bias (6.18%) in eight river basins. EDVI-ET displayed consistent spatiotemporal patterns with global MOD16 ET, with high spatial correlation (R>0.71) and monthly temporal correlation (R>0.82) throughout four seasons. Their differences were also small (<0.56mmday-1) in forests, savannas, grass/shrubs, and croplands. Furthermore, cloud impacts on the regional ET were found to be significant and spatiotemporally heterogeneous. Both EDVI-ET and in-situ observations at seven flux towers indicated that cloud-induced reduction in daily ET could exceed 30% when the cloud cover increased by 60% (R2 of 0.42, fitting line slope of 0.80, p<0.001). Under increased cloud conditions in summer, the changes in net radiation dominated the ET over dense vegetation in southern China, while the roles of air temperature and humidity increased over water-stressed barrens and short vegetation in northwest China. VWC affected EDVI-ET under clouds in temperate transitional zones from flatlands to highlands. This study highlighted the importance of cloud impacts in satellite ET estimation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.AGRFORMET.2013.04.003", "year": 2013, "title": "An efficient method for global parameter sensitivity analysis and its applications to the Australian community land surface model (CABLE)", "abstract": "State-of-the-art global land surface models (LSMs) have a large number (i.e. a few hundred) of parameters. Many of those parameters are poorly constrained and are therefore very uncertain. Usually only a few of the parameters are responsible for changes in the model output of interest. Identifying those parameters that have a significant effect on the model output is an important step before applying parameter estimation methods using observations. However this has not been done systematically for any global LSMs yet, because of the computational costs involved. Here, we introduce a global sensitivity analysis method that is widely used in chemical engineering. This method includes two steps: a screening step that ranks all model parameters by their importance on model output in order to select the potentially important parameters and a second step that aims to quantify the contribution to the variance of model output by each of the pre-selected parameters and by their interactions. This method can be readily applied to any model. Here we apply this method to the Australian community land surface model (CABLE) as an example, and find that the two-step approach is efficient as only 690 model simulations are required to identify the few important parameters amongst the 22 parameters for each of the 10 plant functional types (PFTs) in the first step. Another 256 model simulations are required for the variance based analysis in the second step. We find that the leaf maximum carboxylation rate (vcmax) is by far the most important parameter for global annual gross primary productivity (GPP) across all PFTs. However, if focusing on annual latent heat flux (LE) the importance of the parameters is very much PFT dependent. We suggest that this two-step approach should be used to identify important parameters in global LSMs, so that observations to constrain parameters can be used more efficiently in a subsequent parameter estimation step.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/JCLI-D-18-0605.1", "year": 2019, "title": "Temperature and salinity variability in the SODA3, ECCO4r3, and ORAS5 ocean reanalyses, 1993\u20132015", "abstract": "Abstract This study extends recent ocean reanalysis comparisons to explore improvements to several next-generation products, the Simple Ocean Data Assimilation, version 3 (SODA3); the Estimating the Circulation and Climate of the Ocean, version 4, release 3 (ECCO4r3); and the Ocean Reanalysis System 5 (ORAS5), during their 23-yr period of overlap (19932015). The three reanalyses share similar historical hydrographic data, but the forcings, forward models, estimation algorithms, and bias correction methods are different. The study begins by comparing the reanalyses to independent analyses of historical SST, heat, and salt content, as well as examining the analysis-minus-observation misfits. While the misfits are generally small, they still reveal some systematic biases that are not present in the reference Hadley Center EN4 objective analysis. We next explore global trends in temperature averaged into three depth intervals: 0300, 3001000, and 10002000 m. We find considerable similarity in the spatial structure of the trends and their distribution among different ocean basins; however, the trends in global averages do differ by 30%40%, which implies an equivalent level of disagreement in net surface heating rates. ECCO4r3 is distinct in having quite weak warming trends while ORAS5 has stronger trends that are noticeable in the deeper layers. To examine the performance of the reanalyses in the Arctic we explore representation of Atlantic Water variability on the Atlantic side of the Arctic and upper-halocline freshwater storage on the Pacific side of the Arctic. These comparisons are encouraging for the application of ocean reanalyses to track ocean climate variability and change at high northern latitudes.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-22-245-2022", "year": 2022, "title": "OClO as observed by TROPOMI: a comparison with meteorological parameters and polar stratospheric cloud observations", "abstract": "Abstract. Chlorine dioxide (OClO) is a by-product of the ozone-depleting halogen chemistry in the stratosphere. Although it is rapidly photolysed at low solar zenith angles (SZAs), it plays an important role as an indicator of the chlorine activation in polar regions during polar winter and spring at twilight conditions because of the nearly linear dependence of its formation on chlorine oxide (ClO). Here, we compare slant column densities (SCDs) of chlorine dioxide (OClO) retrieved by means of differential optical absorption spectroscopy (DOAS) from spectra measured by the TROPOspheric Monitoring Instrument (TROPOMI) with meteorological data for both Antarctic and Arctic regions for the first three winters in each of the hemispheres (November 2017October 2020). TROPOMI, a UVVisNIRSWIR instrument on board of the Sentinel-5P satellite, monitors the Earth's atmosphere in a near-polar orbit at an unprecedented spatial resolution and signal-to-noise ratio and provides daily global coverage at the Equator and thus even more frequent observations at polar regions. The observed OClO SCDs are generally well correlated with the meteorological conditions in the polar winter stratosphere; for example, the chlorine activation signal appears as a sharp gradient in the time series of the OClO SCDs once the temperature drops to values well below the nitric acid trihydrate (NAT) existence temperature (TNAT). Also a relation of enhanced OClO values at lee sides of mountains can be observed at the beginning of the winters, indicating a possible effect of lee waves on chlorine activation. The dataset is also compared with CALIPSO Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) polar stratospheric cloud (PSC) observations. In general, OClO SCDs coincide well with CALIOP measurements for which PSCs are detected. Very high OClO levels are observed for the northern hemispheric winter 2019/20, with an extraordinarily long period with a stable polar vortex being even close to the values found for southern hemispheric winters. An extraordinary winter in the Southern Hemisphere was also observed in 2019, with a minor sudden stratospheric warming at the beginning of September. In this winter, similar OClO values were measured in comparison to the previous (usual) winter till that event but with a OClO deactivation that was 12 weeks earlier.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-13-2257-2020", "year": 2020, "title": "A machine-learning-based cloud detection and thermodynamic-phase classification algorithm using passive spectral observations", "abstract": "Abstract. We trained two Random Forest (RF) machine learning models for cloud mask and cloud thermodynamic-phase detection using spectral observations from Visible Infrared Imaging Radiometer Suite (VIIRS) on board Suomi National Polar-orbiting Partnership (SNPP). Observations from Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) were carefully selected to provide reference labels. The two RF models were trained for all-day and daytime-only conditions using a 4-year collocated VIIRS and CALIOP dataset from 2013 to 2016. Due to the orbit difference, the collocated CALIOP and SNPP VIIRS training samples cover a broad-viewing zenith angle range, which is a great benefit to overall model performance. The all-day model uses three VIIRS infrared (IR) bands (8.6, 11, and 12 m), and the daytime model uses five Near-IR (NIR) and Shortwave-IR (SWIR) bands (0.86, 1.24, 1.38, 1.64, and 2.25 m) together with the three IR bands to detect clear, liquid water, and ice cloud pixels. Up to seven surface types, i.e., ocean water, forest, cropland, grassland, snow and ice, barren desert, and shrubland, were considered separately to enhance performance for both models. Detection of cloudy pixels and thermodynamic phase with the two RF models was compared against collocated CALIOP products from 2017. It is shown that, when using a conservative screening process that excludes the most challenging cloudy pixels for passive remote sensing, the two RF models have high accuracy rates in comparison to the CALIOP reference for both cloud detection and thermodynamic phase. Other existing SNPP VIIRS and Aqua MODIS cloud mask and phase products are also evaluated, with results showing that the two RF models and the MODIS MYD06 optical property phase product are the top three algorithms with respect to lidar observations during the daytime. During the nighttime, the RF all-day model works best for both cloud detection and phase, particularly for pixels over snow and ice surfaces. The present RF models can be extended to other similar passive instruments if training samples can be collected from CALIOP or other lidars. However, the quality of reference labels and potential sampling issues that may impact model performance would need further attention.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1109/CISCE55963.2022.9851159", "year": 2022, "title": "A Convolution Neural Network-based Method for Sea Ice Remote Sensing using GNSS-R Data", "abstract": "Sea ice remote sensing is of great significance to the understanding of polar climate change. At present, the global navigation satellite system reflector (GNSS-R) technology has been applied to the study of sea ice remote sensing and achieved good results. In this paper, a convolution neural network (CNN) based method for sea ice recognition (SIR) and estimation of sea ice concentration (SIC) using GNSS-R data is proposed. Specifically, a CNN model is designed to solve the classification problem of SIR and the regression problem of SIC estimation. In the stage of data set construction, first, the global GNSS-R data (TDS-l), in a certain period of time, is spatiotemporally matched with the relatively reliable sea ice data (NSIDC), and then the matched GNSS-R data is extracted to balance the amount of seawater data and sea ice data. In the stage of CNN model construction, the feature learning ability of the model is enhanced by adding convolution layer, pooling layer and full connection layer. Simulation results show that the proposed CNN -based scheme has a higher prediction accuracy of SIR and lower estimation error of SIC than other existing methods.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ESSD-12-611-2020", "year": 2020, "title": "Replacing missing values in the standard Multi-angle Imaging SpectroRadiometer (MISR) radiometric camera-by-camera cloud mask (RCCM) data product", "abstract": "Abstract. The Multi-angle Imaging SpectroRadiometer (MISR) is one of the five instruments hosted on board the NASA Terra platform, launched on 18 December 1999. This instrument has been operational since 24 February 2000 and is still acquiring Earth observation data as of this writing. The primary mission of the MISR is to document the state and properties of the atmosphere, in particular the clouds and aerosols it contains, as well as the planetary surface, on the basis of 36 data channels collectively gathered by its nine cameras (pointing in different directions along the orbital track) in four spectral bands (blue, green, red and near-infrared). The radiometric camera-by-camera cloud mask (RCCM) is derived from the calibrated measurements at the nominal top of the atmosphere and is provided separately for each of the nine cameras. This RCCM data product is permanently archived at the NASA Atmospheric Science Data Center (ASDC) in Hampton, VA, USA, and is openly accessible (Diner et al., 1999b, and https://doi.org/10.5067/Terra/MISR/MIRCCM_L2.004). For various technical reasons described in this paper, this RCCM product exhibits missing data, even though an estimate of the clear or cloudy status of the environment at each individual observed location can be deduced from the available measurements. The aims of this paper are (1) to describe how to replace over 99 % of the missing values by estimates and (2) to briefly describe the software to replace missing RCCM values, which is openly available to the community from the GitHub website, https://github.com/mmverstraete/MISR\\ RCCM/ (last access: 12 March 2020), or https://doi.org/10.5281/ZENODO.3240017 (Verstraete, 2019e). Two additional sets of resources are also made available on the research data repository of GFZ Data Services in conjunction with this paper. The first set (A; Verstraete et al., 2020; https://doi.org/10.5880/fidgeo.2020.004) includes three items: (A1) a compressed archive, RCCM_Out.zip, containing all intermediary, final and ancillary outputs created while generating the figures of this paper; (A2) a user manual, RCCM_Out.pdf, describing how to install, uncompress and explore those files; and (A3) a separate input MISR data archive, RCCM_input_68050.zip, for Path 168, Orbit 68050. This latter archive is usable with (B), the second set (Verstraete and Vogt, 2020; https://doi.org/10.5880/fidgeo.2020.008), which includes (B1), a stand-alone, self-contained, executable version of the RCCM correction codes, RCCM_Soft_Win.zip, using the IDL Virtual Machine technology that does not require a paid IDL license, as well as (B2), a user manual, RCCM_Soft_Win.pdf, to explain how to install, uncompress and use this software.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS14061418", "year": 2022, "title": "An Algorithm to Bias-Correct and Transform Arctic SMAP-Derived Skin Salinities into Bulk Surface Salinities", "abstract": "An algorithmic approach, based on satellite-derived sea-surface (skin) salinities (SSS), is proposed to correct for errors in SSS retrievals and convert these skin salinities into comparable in-situ (bulk) salinities for the top-5 m of the subpolar and Arctic Oceans. In preparation for routine assimilation into operational ocean forecast models, Soil Moisture Active Passive (SMAP) satellite Level-2 SSS observations are transformed using Argo float data from the top-5 m of the ocean to address the mismatch between the skin depth of satellite L-band SSS measurements (1 cm) and the thickness of top model layers (typically at least 1 m). Separate from the challenge of Argo float availability in most of the subpolar and Arctic Oceans, satellite-derived SSS products for these regions currently are not suitable for assimilation for a myriad of other reasons, including erroneous ancillary air-sea forcing/flux products. In the subpolar and Arctic Oceans, the root-mean-square error (RMSE) between the SMAP SSS product and several in-situ salinity observational data sets for the top-5 m is greater than 1.5 pss (Practical Salinity Scale), which can be larger than their temporal variability. Thus, we train a machine-learning algorithm (called a Generalized Additive Model) on in-situ salinities from the top-5 m and an independent air-sea forcing/flux product to convert the SMAP SSS into bulk-salinities, correct biases, and quantify their standard errors. The RMSE between these corrected bulk-salinities and in-situ measurements is less than 1 pss in open ocean regions. Barring persistently problematic data near coasts and ice-pack edges, the corrected bulk-salinity data are in better agreement with in-situ data than their SMAP SSS equivalent.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/MWR-D-22-0145.1", "year": 2022, "title": "A Microphysics-scheme Consistent Snow Optical Parameterization for the Community Radiative Transfer Model", "abstract": "Abstract The satellite observational data assimilation community requires consistent hydrometer descriptionsincluding mass-size relation and particle size distributionto be used in both the forecast model and observation operator. We develop a microphysics scheme-consistent snow and graupel single-scattering property database to meet this requirement. In this database, snowflakes are modeled as a mixture of small column and large aggregated ice particles, the mixing ratios of which may be adjusted to satisfy a given mass-size relation. Snow single-scattering properties are computed for four different mass-size relations. Subsequently, the snow description in the Thompson microphysics scheme is used as an example to demonstrate how microphysics scheme-consistent snow bulk optical properties are derived. The Thompson scheme-consistent snow bulk optical properties are added to the Community Radiative Transfer Model (CRTM) version 2.4.0. With CloudSat Cloud Profiling Radar (CPR) snow and liquid precipitation retrievals as the inputs, CRTM simulations are performed over global oceans and compared with four collocated Global Precipitation Measurement (GPM) Microwave Imager (GMI) high-frequency channel observations. The CRTM simulated brightness temperatures show agreement with the GMI observed brightness temperatures in cases of light-to-moderate precipitation over extratropical and polar ice-free oceans, with root mean square errors (RMSEs) of 4.3, 13.0, 1.8, and 3.3 K in the 166 GHz (vertical polarization), 166 GHz (horizontal polarization), 1833 GHz (vertical polarization), and 1837 GHz (vertical polarization) channels, respectively. The result demonstrates the potential of using the newly developed microphysics scheme-consistent snow optical parameterization in data assimilation applications.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/978-3-030-46133-1_40", "year": 2020, "title": "An aggregate learning approach for interpretable semi-supervised population prediction and disaggregation using ancillary data", "abstract": "Census data provide detailed information about population characteristics at a coarse resolution. Nevertheless, fine-grained, high-resolution mappings of population counts are increasingly needed to characterize population dynamics and to assess the consequences of climate shocks, natural disasters, investments in infrastructure, development policies, etc. Disaggregating these census is a complex machine learning, and multiple solutions have been proposed in past research. We propose in this paper to view the problem in the context of the aggregate learning paradigm, where the output value for all training points is not known, but where it is only known for aggregates of the points (i.e. in this context, for regions of pixels where a census is available). We demonstrate with a very simple and interpretable model that this method is on par, and even outperforms on some metrics, the state-of-the-art, despite its simplicity.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019WR026621", "year": 2020, "title": "Groundwater Storage Loss Associated With Land Subsidence in Western", "abstract": "Land subsidence caused by groundwater extraction has numerous negative consequences, such as loss of groundwater storage and damage to infrastructure. Understanding the magnitude, timing, and locations of land subsidence, as well as the mechanisms driving it, is crucial to implementing mitigation strategies, yet the complex, nonlinear processes causing subsidence are difficult to quantify. Physical models relating groundwater flux to aquifer compaction exist but require substantial hydrological data sets and are time consuming to calibrate. Land deformation can be measured using interferometric synthetic aperture radar (InSAR) and GPS, but the former is computationally expensive to estimate at scale and is subject to tropospheric and ionospheric errors, and the latter leaves many temporal and spatial gaps. In this study, we apply for the first time a machine learning approach that quantifies the relationships of various widely available input data, including evapotranspiration, land use, and sediment thickness, with land subsidence. We apply this method over the Western United States and estimate that from 2015 to 2016, ~2.0 km3/yr of groundwater storage was lost due to groundwater pumping-induced compaction of sediments. Subsidence is concentrated in the Central Valley of California, and the state of California accounts for 75% of total subsidence in the Western United States. Other significant areas of subsidence occur in cultivated regions of the Basin and Range province. This study demonstrates that widely available ancillary data can be used to estimate subsidence at a larger scale than has been previously possible.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS12182933", "year": 2020, "title": "Application of Machine Learning to Debris Flow Susceptibility Mapping along the China\u2013Pakistan Karakoram Highway", "abstract": "The ChinaPakistan Karakoram Highway is an important land route from China to South Asia and the Middle East via Pakistan. Due to the extremely hazardous geological environment around the highway, landslides, debris flows, collapses, and subsidence are frequent. Among them, debris flows are one of the most serious geological hazards on the Karakoram Highway, and they often cause interruptions to traffic and casualties. Therefore, the development of debris flow susceptibility mapping along the highway can potentially facilitate its safe operation. In this study, we used remote sensing, GIS, and machine learning techniques to map debris flow susceptibility along the Karakoram Highway in areas where observation data are scarce and difficult to obtain by field survey. First, the distribution of 544 catchments which are prone to debris flow were identified through visual interpretation of remote sensing images. The factors influencing debris flow susceptibility were then analyzed, and a total of 17 parameters related to geomorphology, soil materials, and triggering conditions were selected. Model training was based on multiple common machine learning methods, including Ensemble Methods, Gaussian Processes, Generalized Linear models, Navies Bayes, Nearest Neighbors, Support Vector Machines, Trees, Discriminant Analysis, and eXtreme Gradient Boosting. Support Vector Classification (SVC) was chosen as the final model after evaluation; its accuracy (ACC) was 0.91, and the area under the ROC curve (AUC) was 0.96. Among the factors involved in SVC, the Melton Ratio (MR) was the most important, followed by drainage density (DD), Hypsometric Integral (HI), and average slope (AS), indicating that geomorphic conditions play an important role in predicting debris flow susceptibility in the study area. SVC was used to map debris flow susceptibility in the study area, and the results will potentially facilitate the safe operation of the highway.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.GEOMORPH.2020.107451", "year": 2021, "title": "Major geomorphic events and natural hazards during monsoonal precipitation 2018 in the Kali Gandaki Valley, Nepal Himalaya", "abstract": "Highest geomorphic activity in the central Nepal Himalayas is mainly driven by monsoonal precipitation. In contrast, the northern flanks of the Nepal Himalaya lay in the relative dry rain shadow of the mountain range. During the monsoon 2018, major floods and geomorphic events occurred in the Kali Gandaki (KG) valley impacting both the monsoon-affected and the dry parts of the catchments. We analyze the events and its triggers based on field observations, multiple satellite image interpretation, climatological analysis using Global Precipitation Measurement and MODIS snow cover data, hydrological analysis and media analysis. The hydro-meteorological triggers are complex. Exceptional precipitation in April and May 2018 occurred in the entire study area, followed by a rather dry period. Precipitation in August was exceptional in the northern part whereas below average in the South. We argue that dynamics of snow accumulation and delayed melting contributed significantly to flooding and increased geomorphic activity in the southern part in August whereas flooding in the northern part was mainly triggered by rainfalls. We thus define 2018 as an abnormal (pre-)monsoon year with less rainfall than average but being more catastrophic. Sediment dynamics in the study area are still controlled by the Dhampu rock avalanche dam and the braided river floodplain north of this knickpoint, where sediment pulses delivered from tributaries are rarely connected from the main river. During the monsoon floods 2018 sediment connectivity was given for most tributaries due to the steepness of the catchments. The study area is subject to major human impact. Mostly in the south, numerous hillslopes have been undercut by road construction, leading to higher geomorphic sensitivity. Severe landslides might thus be triggered in future even by less intense rainfall events. Magnitude and frequency of such abnormal (pre-)monsoon precipitation are highly relevant for sediment flux and natural hazards studies.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ECOINF.2021.101305", "year": 2021, "title": "Evaluating the effect of ecological policies from the pattern change of persistent green patches\u2013A case study of Yan'an in China's Loess Plateau", "abstract": "Evaluation from landscape pattern change can comprehensively reflect the impact of ecological policies on the ecosystem service function. However, previous assessments based on landscape patterns only considered land cover type and ignored the quality of vegetation cover, which could hardly reflect regional differences in restoration durability and sustainability. Based on the temporal phase characteristics of the vegetation index, this study proposes the concept of Persistent Green Patches (PGPs). Taking Yan'an, a key area for the implementation of ecological projects in the Loess Plateau, as a study area, the effect of ecological policies was evaluated from the pattern change of PGPs from 2000 to 2017 through Morphological Spatial Pattern Analysis (MSPA). It is found that (1) the area of PGPs was increased from 14.45% to 44.26% in Yan'an since the implementation of the ecological projects; (2) the Grain for Green projects can hardly form a short-term increase of PGPs; while the Natural Forest Protection projects can quickly increase the PGPs area, its effect would tend to be saturated or even decrease in the long term; (3) the fragmentation and connectivity of the landscape show that the ecological projects promote the connection between different green patches, and improves the overall connectivity of the PGPs. This study provides a new perspective on evaluating the effect of ecological projects, which is expected to provide a reference for the future optimization of relevant ecological policies and regional sustainable development.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/GEA.21866", "year": 2021, "title": "Human-environment interactions in a Bahamian dune landscape: A", "abstract": "Investigations were undertaken following the discovery of two Lucayan burials in an Atlantic coast sand dune on Long Island, The Bahamas (site LN\u2011101), in the aftermath of Hurricane Joaquin in 2015. The dune burials were the first of their kind to be documented and systematically excavated, and they were associated with uncommon Atlantic coast Lucayan sites. We describe the first systematic archaeological prospection and investigation of coastal geomorphology in the region, applying grain\u2011size analysis to assess the dune's natural history; basic geochemical analysis to detect anthropogenic impacts and determine agricultural potential; radiocarbon dating as a chronological anchor for reconstructing dune development; drone mapping and georeferencing to document landscape trajectories; and the potential of clay\u2011like soils with respect to pottery production. Significantly, the dune was relatively stable during and after Lucayan occupation, before Hurricane Joaquin stripped about 10 m from the dune face. The results contribute to refined modeling of past and future impacts, especially those attributed to modern climate change, by linking changes in geomorphology to human activities that began over 1000 years ago. The study contributes to a growing body of Caribbean research into the deep\u2011time impacts of sea\u2011level change, coastal geomorphology, erosion, climate change, and hurricane activity.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/ESSD-14-4445-2022", "year": 2022, "title": "HMRFS-TP: long-term daily gap-free snow cover products over the Tibetan", "abstract": "Abstract. Snow cover plays an essential role in climate change and\nthe hydrological cycle of the Tibetan Plateau. The widely used Moderate\nResolution Imaging Spectroradiometer (MODIS) snow products have two major\nissues: massive data gaps due to frequent clouds and relatively low estimate\naccuracy of snow cover due to complex terrain in this region. Here we\ngenerate long-term daily gap-free snow cover products over the Tibetan\nPlateau at 500 m resolution by applying a hidden Markov random field (HMRF)\ntechnique to the original MODIS snow products over the past two decades. The\ndata gaps of the original MODIS snow products were fully filled by optimally\nintegrating spectral, spatiotemporal, and environmental information within\nHMRF framework. The snow cover estimate accuracy was greatly increased by\nincorporating the spatiotemporal variations of solar radiation due to\nsurface topography and sun elevation angle as the environmental contextual\ninformation in HMRF-based snow cover estimation. We evaluated our snow\nproducts, and the accuracy is 98.29 % in comparison with in situ observations, and\n91.36 % in comparison with high-resolution snow maps derived from Landsat\nimages. Our evaluation also suggests that the incorporation of\nspatiotemporal solar radiation as the environmental contextual information\nin HMRF modeling, instead of the simple use of surface elevation as the\nenvironmental contextual information, results in the accuracy of the snow\nproducts increases by 2.71 % and the omission error decreases by 3.59 %.\nThe accuracy of our snow products is especially improved during snow\ntransitional period, and over complex terrains with high elevation and\nsunny slopes. The new products can provide long-term and spatiotemporally\ncontinuous information of snow cover distribution, which is critical for\nunderstanding the processes of snow accumulation and melting, analyzing its\nimpact on climate change, and facilitating water resource management in\nTibetan Plateau. This dataset can be freely accessed from the National\nTibetan Plateau Data Center at https://doi.org/10.11888/Cryos.tpdc.272204\n(Huang and Xu, 2022).", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.RSE.2020.111680", "year": 2020, "title": "Soil moisture experiment in the Luan River supporting new satellite mission opportunities", "abstract": "The Soil Moisture Experiment in the Luan River (SMELR) was conducted from 2017 to 2018 in the semi-arid Luan River watershed located in the North of China. One of the objectives of SMELR is to serve as an assessment tool and demonstration for a new Terrestrial Water Resources Satellite (TWRS) concept with one-dimensional synthetic aperture microwave techniques, for which soil moisture retrieval under variable satellite observing configurations (mainly in terms of incidence angels) is the greatest challenge. This proposed mission is targeted to provide continuity for the current satellite L-band microwave observations, and further improve the accuracy and spatial resolution of soil moisture mapping through the synergistic use of active, passive and optical remote sensing data. Multi-resolution, multi-angle and multi-spectral airborne data were obtained four times over a 70 km by 12 km area in the Shandian River basin, and one time over a 165 km by 5 km area that includes the Xiaoluan River basin. The near surface soil moisture (0 cm5 cm) was measured extensively on the ground in fifty 1 km by 2 km quadrats (targeted to compare with the airborne radiometer), and two hundred and fifty 200 m by 200 m quadrats corresponding to radar observations. Two networks were established for continuous measurement of the soil moisture and temperature profile (3 cm, 5 cm, 10 cm, 20 cm, 50 cm) and precipitation in the Shandian and Xiaoluan River basin, respectively. Supporting ground measurements also included ground temperature, vegetation water content, surface roughness, continuous measurement of microwave emission and backscatter at a pasture site, reflectance of various land cover types, evapotranspiration and aerosol observations. Preliminary results within the experimental area indicate that (1) the near surface soil moisture spatial variability at a 200 m scale was up to ~0.1 cm3/cm3 at an intermediate value of ~0.35 cm3/cm3. (2) The difference of soil and vegetation temperature in grass and croplands reach its maximum of 11 K around solar noon time, and the soil temperature gradient is largest at around 15 P.M. (3) Both the airborne and ground measurements cover a wide range of conditions. The L-band active and passive observations exhibit a large variation of ~30 dB and ~80 K, respectively, corresponding to soil moisture range from 0.1 cm3/cm3 to 0.5 cm3/cm3. The sensitivity of both active and passive data to soil moisture is compared at corresponding spatial resolutions and show high information complementarity for better accuracy and resolution soil moisture retrieval.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1175/JHM-D-15-0157.1", "year": 2016, "title": "Assimilation of gridded GRACE terrestrial water storage estimates in the North American Land Data Assimilation System", "abstract": "Abstract The objective of the North American Land Data Assimilation System (NLDAS) is to provide best-available estimates of near-surface meteorological conditions and soil hydrological status for the continental United States. To support the ongoing efforts to develop data assimilation (DA) capabilities for NLDAS, the results of Gravity Recovery and Climate Experiment (GRACE) DA implemented in a manner consistent with NLDAS development are presented. Following previous work, GRACE terrestrial water storage (TWS) anomaly estimates are assimilated into the NASA Catchment land surface model using an ensemble smoother. In contrast to many earlier GRACE DA studies, a gridded GRACE TWS product is assimilated, spatially distributed GRACE error estimates are accounted for, and the impact that GRACE scaling factors have on assimilation is evaluated. Comparisons with quality-controlled in situ observations indicate that GRACE DA has a positive impact on the simulation of unconfined groundwater variability across the majority of the eastern United States and on the simulation of surface and root zone soil moisture across the country. Smaller improvements are seen in the simulation of snow depth, and the impact of GRACE DA on simulated river discharge and evapotranspiration is regionally variable. The use of GRACE scaling factors during assimilation improved DA results in the western United States but led to small degradations in the eastern United States. The study also found comparable performance between the use of gridded and basin-averaged GRACE observations in assimilation. Finally, the evaluations presented in the paper indicate that GRACE DA can be helpful in improving the representation of droughts.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2018JG004799", "year": 2019, "title": "Seasonal Precipitation Legacy Effects Determine the Carbon Balance of a Semiarid Grassland", "abstract": "Semiarid grasslands are water-limited ecosystems where precipitation (PPT) controls the onset and duration of the growing season; however, this variable does not fully explain interannual variability of productivity at temporal scales. We examined the relationship between PPT and carbon (C) fluxes in a semiarid grassland at both seasonal and interannual scales, as well as the role of lagged effects of PPT and asymmetric sensitivities of net ecosystem carbon exchange to PPT and its components (gross ecosystem exchange [GEE] and ecosystem respiration [ER]). Six years of continuous net ecosystem C exchange data measured with the eddy covariance technique and GEE estimated with 15 years of enhanced vegetation index and the gross primary productivity of Moderate Resolution Imaging Spectroradiometer were used. The semiarid grassland was a C source and a C sink among contrasting PPT years (114 to -107 g C\u00b7m-2\u00b7year-1). At seasonal scale, PPT relationship with the 15 years of GEE derived from enhanced vegetation index and gross primary productivity was sigmoidal. Moreover, PPT legacies of the previous dry season determined the C balance of the grassland by affecting the C uptake and ecosystem respiration of the following growing season, but productivity was more sensitive to PPT changes than respiration. Models of climate change for semiarid grasslands in North America predict up to 30% reduction of winter-spring PPT and slight summer PPT decrease. Thus, our results suggest that future changes in PPT may have a strong impact on the C uptake capacity of this ecosystem due to weakened legacy effects in summer C uptake.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1590/0001-3765202220211352", "year": 2022, "title": "Landslides associated with recent road constructions in the R\u00edo Lucma catchment, eastern Cordillera Blanca, Peru", "abstract": "Abstract Extensive road construction works recently took place in the remote eastern part of the Peruvian Cordillera Blanca, aiming at a better connection of isolated mountain communities with regional administrative centres. Here we document and characterize landslides associated with these road construction efforts in the Rio Lucma catchment, Peru. We show that a total area of 321,332 m2 has been affected by landslides along the 47.1 km of roads constructed between 2015 and 2018. While landslides downslope the roads (48.2%) and complex landslides crossing the roads (46.4%) were the most frequent landslide types in relation to the position of the road; slide-type movement (60.7%) prevails over the flow-type movement (39.3%). Timewise, we found that 75.0% of landslides were observed simultaneously with road construction work, while the remaining 25.0% occurred up to seven months after the roads had been constructed. We plotted the lagged occurrence of these subsequent landslides against precipitation data, showing that 85.7% of them were observed during the wet season (November to April). We conclude that the majority of mapped landslides were directly associated with road constructions and that the road constructions also may set preconditions for landslides, which mainly occurred during the subsequent wet season.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS14153629", "year": 2022, "title": "Phenological Responses to Snow Seasonality in the Qilian Mountains Is a Function of Both Elevation and Vegetation Types", "abstract": "In high-elevation mountains, seasonal snow cover affects land surface phenology and the functioning of the ecosystem. However, studies regarding the long-term effects of snow cover on phenological changes for high mountains are still limited. Our study is based on MODIS data from 2003 to 2021. First, the NDPI was calculated, time series were reconstructed, and an SG filter was used. Land surface phenology metrics were estimated based on the dynamic thresholding method. Then, snow seasonality metrics were also estimated based on snow seasonality extraction rules. Finally, correlation and significance between snow seasonality and land surface phenology metrics were tested. Changes were analyzed across elevation and vegetation types. Results showed that (1) the asymmetry in the significant correlation between the snow seasonality and land surface phenology metrics suggests that a more snow-prone non-growing season (earlier first snow, later snowmelt, longer snow season and more snow cover days) benefits a more flourishing vegetation growing season in the following year (earlier start and later end of growing season, longer growing season). (2) Vegetation phenology metrics above 3500 m is sensitive to the length of the snow season and the number of snow cover days. The effect of first snow day on vegetation phenology shifts around 3300 m. The later snowmelt favors earlier and longer vegetation growing season regardless of the elevation. (3) The sensitivity of land surface phenology metrics to snow seasonality varied among vegetation types. Grass and shrub are sensitive to last snow day, alpine vegetation to snow season length, desert to number of snow cover days, and forest to first snow day. In this study, we used a more reliable NDPI at high elevations and confirmed the past conclusions about the impact of snow seasonality metrics. We also described in detail the curves of snow seasonal metrics effects with elevation change. This study reveals the relationship between land surface phenology and snow seasonality in the Qilian Mountains and has important implications for quantifying the impact of climate change on ecosystems.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.RSE.2020.111668", "year": 2020, "title": "Improvement of operational airborne gamma radiation snow water equivalent estimates using SMAP soil moisture", "abstract": "Knowledge of snow water equivalent (SWE) magnitude and spatial distribution are keys to improving snowmelt flood predictions. Since the 1980s, the operational National Oceanic and Atmospheric Administration's (NOAA) airborne gamma radiation soil moisture (SM) and SWE survey has provided over 20,000 SWE observations to regional National Weather Service (NWS) River Forecast Centers (RFCs). Because the gamma SWE algorithm is based on the difference in natural gamma emission measurements from the soil between bare (fall) and snow-covered (winter) conditions, it requires a baseline fall SM for each flight line. The operational approach assumes the fall SM remains constant throughout that winter's SWE survey. However, early-winter snowmelt and rainfall events after the fall SM surveys have the potential to introduce large biases into airborne gamma SWE estimates. In this study, operational airborne gamma radiation SWE measurements were improved by updating the baseline fall SM with Soil Moisture Active Passive (SMAP) enhanced SM measurements immediately prior to winter onset over the north-central and eastern United States and southern Canada from September 2015 to April 2018. The operational airborne gamma SM had strong agreement with the SMAP SM (Pearson's correlation coefficient, R = 0.69, unbiased root mean square difference, ubRMSD = 0.057 m3/m3), compared to the Advanced Microwave Scanning Radiometer 2 (AMSR2) SM (R = 0.45, ubRMSD = 0.072 m3/m3) and the North American Land Data Assimilation System Phase 2 (NLDAS-2) Mosaic SM products (R = 0.53, ubRMSD = 0.069 m3/m3) in non-forested regions. The SMAP-enhanced gamma SWE was evaluated with satellite-based SWE (R = 0.57, ubRMSD = 34 mm) from the Special Sensor Microwave Imager Sounder (SSMIS) and in-situ SWE (R = 0.710.96) from the Soil Climate Analysis Network and United States Army Corps of Engineer (USACE) St. Paul District, which had better agreement than the operational gamma SWE (R = 0.48, ubRMSD = 36 mm for SSMIS and R = 0.650.75 for in-situ SWE). The results contribute to improving snowmelt flood predictions as well as the accuracy of the NOAA SNOw Data Assimilation System.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S41748-021-00213-W", "year": 2021, "title": "Investigating decadal changes of multiple hydrological products and land-cover changes in the Mediterranean Region for 2009\u20132018", "abstract": "Land-cover change is a critical concern due to its climatic, ecological, and socioeconomic consequences. In this study, we used multiple variables including precipitation, vegetation index, surface soil moisture, and evapotranspiration obtained from different satellite sources to study their association with land-cover changes in the Mediterranean region. Both observational and modeling data were used for climatology and correlation analysis. Famine Early Warning Systems Network (FEWS NET) Land Data Assimilation System (FLDAS) and Global Land Data Assimilation System (GLDAS) were used to extract surface soil moisture and evapotranspiration data. Intercomparing the results of FLDAS and GLDAS suggested that FLDAS data had better accuracy compared to GLDAS for its better coherence with observational data. Climate Hazards Group Infra-Red Precipitation with Station Data (version 2.0 final) (CHIRPS Pentad) were used to extract precipitation data while Moderate Resolution Imaging Spectroradiometer (MODIS) products were used to extract the vegetation indices used in this study. The land-cover change detection was demonstrated during the 20092018 period using MODIS Land-Cover data. Some of the barren and crop lands in Euphrates-Tigris and Algeria have converted to low-vegetated shrublands over the time, while shrublands and barren areas in Egypts southwestern Delta region became grasslands. These observations were well explained by changing trends of hydrological variables which showed that precipitation and soil moisture had higher values in the countries located to the east of the Mediterranean region compared to the ones on the west. For evapotranspiration, the countries in the north had lower values except for countries in Europe such as Bosnia, Romania, Slovenia, and countries in Africa such as Egypt and Libya. The enhanced vegetation index appeared to be decreasing from north to south, with countries in the north such as Germany, Romania, and Czechia having higher values, while countries in the south such as Libya, Egypt, and Iraq having lower trends. Time series analysis for selected countries was also done to understand the change in hydrological parameters, including Enhanced Vegetation Index, evapotranspiration, and soil moisture, which showed alternating drop and rise as well as stagnant values for different parameters in each country.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS13173531", "year": 2021, "title": "Projecting Future Vegetation Change for Northeast China Using CMIP6 Model", "abstract": "Northeast China lies in the transition zone from the humid monsoonal to the arid continental climate, with diverse ecosystems and agricultural land highly susceptible to climate change. This region has experienced significant greening in the past three decades, but future trends remain uncertain. In this study, we provide a quantitative assessment of how vegetation, indicated by the leaf area index (LAI), will change in this region in response to future climate change. Based on the output of eleven CMIP6 global climates, Northeast China is likely to get warmer and wetter in the future, corresponding to an increase in regional LAI. Under the medium emissions scenario (SSP245), the average LAI is expected to increase by 0.27 for the mid-century (20412070) and 0.39 for the late century (20712100). Under the high emissions scenario (SSP585), the increase is 0.40 for the mid-century and 0.70 for the late century, respectively. Despite the increase in the regional mean, the LAI trend shows significant spatial heterogeneity, with likely decreases for the arid northwest and some sandy fields in this region. Therefore, climate change could pose additional challenges for long-term ecological and economic sustainability. Our findings could provide useful information to local decision makers for developing effective sustainable land management strategies in Northeast China.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS13030347", "year": 2021, "title": "Spatial Distribution of Soil Moisture in Mongolia Using SMAP and MODIS", "abstract": "Soil moisture is one of the essential variables of the water cycle, and plays a vital role in agriculture, water management, and land (drought) and vegetation cover change as well as climate change studies. The spatial distribution of soil moisture with high-resolution images in Mongolia has long been one of the essential issues in the remote sensing and agricultural community. In this research, we focused on the distribution of soil moisture and compared the monthly precipitation/temperature and crop yield from 2010 to 2020. In the present study, Soil Moisture Active Passive (SMAP) and Moderate Resolution Imaging Spectroradiometer (MODIS) data were used, including the MOD13A2 Normalized Difference Vegetation Index (NDVI), MOD11A2 Land Surface Temperature (LST), and precipitation/temperature monthly data from the Climate Research Unit (CRU) from 2010 to 2020 over Mongolia. Multiple linear regression methods have previously been used for soil moisture estimation, and in this study, the Autoregressive Integrated Moving Arima (ARIMA) model was used for soil moisture forecasting. The results show that the correlation was statistically significant between SM-MOD and soil moisture content (SMC) from the meteorological stations at different depths (p < 0.0001 at 020 cm and p < 0.005 at 050 cm). The correlation between SM-MOD and temperature, as represented by the correlation coefficient (r), was 0.80 and considered statistically significant (p < 0.0001). However, when SM-MOD was compared with the crop yield for each year (20102019), the correlation coefficient (r) was 0.84. The ARIMA (12, 1, 12) model was selected for the soil moisture time series analysis when predicting soil moisture from 2020 to 2025. The forecasting results are shown for the 95 percent confidence interval. The soil moisture estimation approach and model in our study can serve as a valuable tool for confident and convenient observations of agricultural drought for decision-makers and farmers in Mongolia.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/LAND11060808", "year": 2022, "title": "Potential Variation of Evapotranspiration Induced by Typical Vegetation Changes in Northwest China", "abstract": "Evapotranspiration (ET), as a key eco-hydrological parameter, plays an important role in understanding sustainable ecosystem development. Each plant category has a unique functional trait on transpiration and photosynthesis, with ET implying that water cycle and energy transformation is linked with vegetation type. Changes in surface vegetation directly alter biophysical land surface properties, hence affecting energy and ET transfer. With the rapid increase in land surface changes, there is a need to further understand and quantify the effects of vegetation change on ET, especially over the vulnerable water-cycle region in the arid and semi-arid regions of Northwest China. We adopted the GlobalLand30 land cover and MOD16A2 in 2010 and 2020 to investigate, discuss the spatio-temporal characteristics of annual and seasonal ET of cultivated land, grassland, and forests in Northwest China, and quantify the impact on vegetation changes with absolute and relative changes from different climatic subecoregions on ET. Our results show the following: (1) Forest ET was generally the highest at 688 mm, followed by cultivated land and grassland with 200400 mm in arid climatic subecoregions. (2) Returning cultivated land to forests and cultivated land expansion potentially enhances ET by 90110 mm/10a, with the relative rate of change increasing by 22.1% and 45.8%, respectively, away from unchanged vegetation within identical subecoregions. (3) The ET of most investigated areas gains the highest value in summer, followed by spring, autumn, and winter. This study provides reference for sustainable ecosystem development and the reasonable utilization of limited water resources in Northwest China.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2021JG006568", "year": 2022, "title": "Quantification of Urban Forest and Grassland Carbon Fluxes Using Field Measurements and a Satellite\u2010Based Model in Washington DC/Baltimore Area", "abstract": "Cities are taking the lead on climate change mitigation with ambitious goals to reduce carbon dioxide (CO2) emissions. The implementation of effective mitigation policies will require accurate measurements to guide policy decisions and monitor their efficacy. Here, we present a comprehensive CO2 inventory of an urban temperate forest and unmanaged grassland using field observations. We estimate the annual storage of CO2 by vegetation and soils and place our biogenic flux estimates in the context of local fossil fuel (FF) emissions to determine when, where, and by how much biogenic fluxes alter net CO2 flux dynamics. We compare our hourly estimates of biogenic fluxes in the forest site to modeled estimates using a modified version of Urban-Vegetation Photosynthesis and Respiration Model (Urban-VPRM) in Washington DC/Baltimore area presenting the first urban evaluation of this model. We estimate that vegetation results in a net biogenic uptake of -2.62 \u00b1 1.9 Mg C ha-1 yr-1 in the forest site. FF emissions, however, drive patterns in the net flux resulting in the region being a net source of CO2 on daily and annual timescales. In the summer afternoons, however, the net flux is dominated by the uptake of CO2 by vegetation. The Urban-VPRM closely approximates hourly forest inventory based estimates of gross ecosystem exchange but overestimates ecosystem respiration in the dormant season by 40%. Our study highlights the importance of including seasonal dynamics in biogenic CO2 fluxes when planning and testing the efficacy of CO2 emission reduction polices and development of monitoring programs.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.158819", "year": 2023, "title": "Soil moisture drives the spatiotemporal patterns of asymmetry in vegetation productivity responses across China", "abstract": "Increasingly drastic global change is expected to cause hydroclimatic changes, which will influence vegetation productivity and pose a threat to the terrestrial carbon sink. Asymmetry represents an imbalance between vegetation growth and loss of growth during dry and wet periods, respectively. However, the mechanisms of asymmetric plant responses to hydrological changes remain poorly understood. Here, we examined the spatiotemporal patterns of asymmetric responses of vegetation productivity across terrestrial ecosystems in China. We analyzed several observational and satellite-based datasets of plant productivity and several reanalyzed datasets of hydroclimatic variables from 2001 to 2020, and used a random forest model to assess the importance of hydroclimatic variables for these responses. Our results showed that the productivity of >50 % of China's vegetated areas showed a more positive asymmetry (2.3 9.4 %) over the study period, which were distributed broadly in northwest China (mainly grasslands and sparse vegetation ecosystems). Negative asymmetries were most common in forest ecosystems in northeast China. We demonstrated that one-third of vegetated areas tended to exhibit significant changes in asymmetry during 20012020. The trend towards stronger positive asymmetry (0.95 % yr1) was higher than that towards stronger negative asymmetry (0.55 % yr1), which is beneficial for the carbon sink. We further showed that in China, soil moisture was a more important driver of spatiotemporal changes in asymmetric productivity than precipitation. We identified thresholds of surface soil moisture (2030 %, volume water content) and root-zone soil moisture (200350 mm, equivalent water height) that were associated with changes in asymmetry. Our findings highlight the necessity of considering the dynamic responses of vegetation to hydrological factors in order to fully understand the physiological growth processes of plants and avoid the possible loss of productivity due to future climate change.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/IJERPH18020416", "year": 2021, "title": "Quantifying Grass Coverage Trends to Identify the Hot Plots of Grassland Degradation in the Tibetan Plateau during 2000\u20132019", "abstract": "Grassland covers 54% of the Tibetan Plateau (TP) and suffered overgrazing and degradation problems during past decades. To alleviate these problems, a series of policy measures have been implemented during recent two decades and inevitably caused changes of the grassland. To this end, this study quantitatively analyzed the grassland changes and the effects of reduced grazing intensity, and identified the hot plots of grassland degradation in the TP during 20002019. The grassland status was indicated by the Fractional Vegetation Cover in the green grass period (GP), i.e., FVCGP, and its changes and spatial variations were detected by analyzing the FVCGP trends and their distribution, using the MannKendal, Sens Slope, and ArcGIS buffering methods, and data of the MOD13Q1 Collection 6 products and other sources. The results showed that 62.12% of the grasslands were significantly increased in the FVCGP, and 28.34% had no apparent changes. The remaining 9.54% of the grassland significantly decreased in the FVCGP, mainly occurring in the areas nearby roads, rivers, and lakes, and distributed mostly in a point pattern. Of the total FVCGP decreased grassland area, 27.03% was clustered and identified as the hot plots of grassland degradation in six main regions. Decreased grazing intensity and increased precipitation contributed to the increase of grassland FVC in the TP, while local overgrazing could be the main cause of the FVC decrease. To strength the grassland restoration in the TP, the government supports and supervision should be enhanced to further mitigate the grassland pressure of animal grazing, particularly in the hot plot areas of degradation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1175/JAMC-D-18-0219.1", "year": 2019, "title": "Variations in surface albedo arising from flooding and desiccation cycles on the Bonneville Salt Flats, Utah", "abstract": "Abstract Desert playas, such as those in northern Utah, form a landscape often in stark contrast to surrounding mountain ranges due to their minimal topographic relief, lack of vegetation, and saline soils. Dry highly reflective halite surfaces, which make up many of the desert playas in northern Utah, are generally characterized by a surface albedo over 40%. However, their albedo can be reduced abruptly to less than 20% by flooding due to rainfall, runoff from surrounding higher terrain, or surface winds transporting shallow water across the playas. A weather station installed during September 2016 to study the Bonneville Salt Flats (BSF) in northern Utah provides estimates of surface albedo that can be related to cycles of flooding and desiccation of the halite surface. The normalized difference water index (NDWI) derived from the MODIS MOD09A1 land surface reflectance product estimates the fractional coverage of surface water over the BSF. NDWI values computed over 8-day periods from 2000 to 2018 highlight year-to-year and seasonal variations in playa flooding events over the BSF. Periods of playa flooding were observed with both ground-based observations and NDWI with sharp reductions in albedo when the surface is flooded.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/SOIL-7-217-2021", "year": 2021, "title": "SoilGrids 2.0: producing soil information for the globe with quantified spatial uncertainty", "abstract": "Abstract. SoilGrids produces maps of soil properties for the entire globe at medium spatial resolution (250 m cell size) using state-of-the-art machine learning methods to generate the necessary models. It takes as inputs soil observations from about 240 000 locations worldwide and over 400 global environmental covariates describing vegetation, terrain morphology, climate, geology and hydrology. The aim of this work was the production of global maps of soil properties, with cross-validation, hyper-parameter selection and quantification of spatially explicit uncertainty, as implemented in the SoilGrids version 2.0 product incorporating state-of-the-art practices and adapting them for global digital soil mapping with legacy data. The paper presents the evaluation of the global predictions produced for soil organic carbon content, total nitrogen, coarse fragments, pH (water), cation exchange capacity, bulk density and texture fractions at six standard depths (up to 200 cm). The quantitative evaluation showed metrics in line with previous global, continental and large-region studies. The qualitative evaluation showed that coarse-scale patterns are well reproduced. The spatial uncertainty at global scale highlighted the need for more soil observations, especially in high-latitude regions.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.14712/23361980.2022.5", "year": 2022, "title": "Current Global Land Systems Classifications: Comparison of Methods and Outputs", "abstract": "The anthropogenic impact on the functioning of natural systems and the concept of Anthropocene as a period of the human domination of the Earth has been widely discussed in literature in the past few decades. Consequently, several land systems classifications have been developed on a global scale to capture the diversity, intensity, and spatial distribution of the human suppression of natural stratification. This review presents the comparison of the most widely used complex global classifications, incorporating both natural conditions and the human influence on nature. Methods, input data, the number and type of output categories as well as their geographical extent and distribution are described and compared. The review will help potential users to find differences between available classifications and choose the right one for a particular use.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1002/LDR.3494", "year": 2020, "title": "A novel similar habitat potential model based on sliding-window technique for vegetation restoration potential mapping", "abstract": "Vegetation restoration potential mapping (VRPM) is of great importance for regional ecosystem restoration planning after long\u2011term land degradation or short\u2011term disasters. However, there are some problems to be solved in the current models for evaluating the potential of vegetation restoration. First, the models for VRPM are mostly established based on a knowledge\u2011driven index system. Although this kind of model is logically rigorous, it relies too much on expert knowledge and is relatively inefficient, especially for large\u2011area vegetation restoration assessments. Second, because of the spatial heterogeneity, as well as the absence of important indicators, the traditional global\u2011based evaluation models are difficult to adapt to the entire study area. In this study, an improved data\u2011driven approach, that is, a sliding\u2011window based similar habitat potential model, is developed for VRPM. The advantages of the new model include: (a) it is more efficient in determining the importance of each influencing factor without resorting to expert knowledge; (b) it is more locally adaptive than the global model because it performs sample training, rule building, and vegetation restoration potential calculation in each current local window. We provide a case\u2011study to show the modeling process and result interpretation of the new model.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/HESS-26-6311-2022", "year": 2022, "title": "Simulating carbon and water fluxes using a coupled process-based terrestrial biosphere model and joint assimilation of leaf area index and surface soil \u2026", "abstract": "Abstract. Reliable modeling of carbon and water fluxes is essential for understanding the terrestrial carbon and water cycles and informing policy strategies aimed at constraining carbon emissions and improving water use efficiency. We designed an assimilation framework (LPJ-Vegetation and soil moisture Joint Assimilation, or LPJ-VSJA) to improve gross primary production (GPP) and evapotranspiration (ET) estimates globally. The integrated model, LPJ-PM (LPJ-PT-JPLSM Model) as the underlying model, was coupled from the LundPotsdamJena Dynamic Global Vegetation Model (LPJ-DGVM version 3.01) and a hydrology module (i.e., the updated PriestleyTaylor Jet Propulsion Laboratory model, PT-JPLSM). Satellite-based soil moisture products derived from the Soil Moisture and Ocean Salinity (SMOS) and Soil Moisture Active and Passive (SMAP) and leaf area index (LAI) from the Global LAnd and Surface Satellite (GLASS) product were assimilated into LPJ-PM to improve GPP and ET simulations using a proper orthogonal decomposition (POD)-based ensemble four-dimensional variational assimilation method (PODEn4DVar). The joint assimilation framework LPJ-VSJA achieved the best model performance (with an R2 ( coefficient of determination) of 0.91 and 0.81 and an ubRMSD (unbiased root mean square deviation) reduced by 40.3 % and 29.9 % for GPP and ET, respectively, compared with those of LPJ-DGVM at the monthly scale). The GPP and ET resulting from the assimilation demonstrated a better performance in the arid and semi-arid regions (GPP: R2 = 0.73, ubRMSD = 1.05 g C m2 d1; ET: R2 = 0.73, ubRMSD = 0.61 mm d1) than in the humid and sub-dry humid regions (GPP: R2 = 0.61, ubRMSD = 1.23 g C m2 d1; ET: R2 = 0.66; ubRMSD = 0.67 mm d1). The ET simulated by LPJ-PM that assimilated SMAP or SMOS data had a slight difference, and the SMAP soil moisture data performed better than SMOS data. Our global simulation modeled by LPJ-VSJA was compared with several global GPP and ET products (e.g., GLASS GPP, GOSIF GPP, GLDAS ET, and GLEAM ET) using the triple collocation (TC) method. Our products, especially ET, exhibited advantages in the overall error distribution (estimated error (): 3.4 mm per month; estimated standard deviation of : 1.91 mm per month). Our research showed that the assimilation of multiple datasets could reduce model uncertainties, while the model performance differed across regions and plant functional types. Our assimilation framework (LPJ-VSJA) can improve the model simulation performance of daily GPP and ET globally, especially in water-limited regions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/LDR.4338", "year": 2022, "title": "A novel framework for evaluating the effect of vegetation restoration via the grazing\u2010exclusion\u2010by\u2010fencing project: a case study from the Qinghai\u2010Tibet Plateau", "abstract": "Grazing exclusion by fencing (GEF) has been implemented to prevent the deterioration of grassland ecosystems in China since the beginning of this century; meanwhile, the effects have attracted widespread attention from the academic community. However, due to the simultaneity of different factors, it is difficult to separate the effect of different policies from natural resource endowments and identify the independent role of each policy. In this study, a novel framework was established based on spatiotemporal statistics. First, an indicator\u2011denoted vegetation restoration potential achievement degree (VRPAD) was introduced to lessen the impact of resource endowment conditions. Second, a double\u2011difference model of both space and time was developed to reflect the net improvement of VRPAD brought by GEF. The case study showed that 15 out of the 17 fenced\u2011off enclosures achieved positive VRPAD growth since the GEF implementation, while only 58.8% showed a much faster improvement or a slower degeneration than their adjacent areas. It was also found GEF effect presented apparent administrative differences in terms of spatial distribution. The number of effective fences accounted for 75% in Mami Town, but it was 0 in Chabu Town. It is concluded that the role of GEF may be overestimated, multi\u2011pronged approaches are more conducive to vegetation restoration, and strengthening grassroots management and self\u2011policing of fences is important to improve GEF efficiency. This research provides a novel framework for distinguishing policy effect and is expected to inspire new ideas and methodological support for policy formulation and evaluation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12524-020-01195-4", "year": 2020, "title": "Increased Surface Broadband Emissivity Driven by Denser Vegetation on the Tibetan Plateau Grassland Area", "abstract": "Global changes are profoundly affecting the global terrestrial ecosystems, especially for the vegetation. Simultaneously, the affected vegetation gives feedback to the climates. The Tibetan Plateau (TP), one of the most sensitive areas to global changes, has undergone extraordinary changes on its ecosystem processes. In the multitudinous land surface ecosystem processes affecting the climate, the process of land surface energy balance affecting by vegetation activity is one of the most important and still has not been well recognized. The spatial and temporal patterns of the broadband emissivity (BBE) on the TP and its relations to the vegetation activity and land surface temperature were examined in this research. We find that elevated BBE is regulated by increasing vegetation activity for grasslands over the TP from 2000 to 2015. The spatial patterns of BBE and its interannual changes are highly correlated with vegetation activity. The BBE changing rate generally declines along rising elevation, due to the shrunk effects from vegetation activity. A greater sensitivity of BBE to vegetation activity occurs in the sparse vegetation area or high elevation zone than in the dense vegetation area or low elevation zone. Increasing BBE has a cooling effect on the land surface, especially at night. This cooling effect is related to wind speed. The growing season BBE trend as regulated by vegetation activity highlights the importance to take mounting notice of the growing season long-wave energy fluxes of surface energy balance studies in the future.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.159064", "year": 2023, "title": "Spatial patterns and climatic drivers of leaf spring phenology of maple in eastern North America", "abstract": "The resurgent frequency of extreme weather events and their strongly distinctive spatial patterns lead to a growing interest in phenology as an indicator of tree susceptibility. Using a long-term chronology of observations collected in situ, we predicted and investigated the spatial patterns and environmental drivers of spring leaf phenology across maple stand polygons dominated by Acer saccharum Marsh. and/or Acer rubra L. in eastern North America for 20002018. Model calibration was based on Bayesian ordinal regressions relating the timing of the phenological events' observations to the MODIS vegetation indices EVI, NDVI and LAI. DAYMET data have been extracted to compute temperature and precipitation during spring phenology. Model accuracy increased as the season progressed, with prediction uncertainty spanning from 9 days for bud swelling to 4 days for leaf unfolding. NDVI and LAI were the best predictors for the onset and ending of spring phenology, respectively. Bud swelling occurred at the end of March in the early stands and at the onset of May in the late stands, while leaf unfolding was completed at the beginning of April for the early and in mid-June for the late stands. Early and late stands polarized towards a south-westnorth-east gradient. In the south-western regions, which are also the driest, total precipitation and minimum temperature explained respectively 73 % and 25 % of the duration of spring phenology. In the north-eastern regions, precipitation and minimum temperature explained 62 % and 26 % of the duration of spring phenology. Our results suggest high vulnerability to extreme weather events in stands located in the south-west of the species distribution. The increasing incidence of drought in these locations might affect spring phenology, decreasing net primary production in these stands. Warmer nights might expose the buds to late frosts, events that are expected to become more frequent in the coming years.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.154761", "year": 2022, "title": "Sedimentary organic carbon storage of thermokarst lakes and ponds across Tibetan permafrost region", "abstract": "Sedimentary soil organic carbon (SOC) stored in thermokarst lakes and ponds (hereafter referred to as thaw lakes) across high-latitude/altitude permafrost areas is of global significance due to increasing thaw lake numbers and their high C vulnerability under climate warming. However, to date, little is known about the SOC storage in these lakes, which limits our better understanding of the fate of these active carbon in a warming future. Here, by combining large-scale field observation data and published deep (e.g., 0300 cm) permafrost SOC data with a random forest (RF) machine learning technique, we provided the first comprehensive estimation of thaw lake SOC stocks to 3 m depth on the Tibetan Plateau. This study demonstrated that combining multiple environmental factors with the RF model could effectively predict the spatial distributions of the thaw lake SOC density values (SOCDs). The model results revealed that the soil respiration, normalized difference vegetation index (NDVI), and mean annual precipitation (MAP) were the most influential factors for predicting thaw lake SOCDs. In total, the sedimentary SOC stocks in the thaw lakes were approximately 52.62 Tg in the top 3 m, with 53% of the SOC stored in the upper layers (0100 cm). The SOCDs generally exhibited high values in eastern Tibetan Plateau, and low values in mid- and western Tibetan Plateau, which were similar to the patterns of the land cover types that affected the SOCDs. We further found that the SOCDs of thaw lakes were generally higher than those of their surrounding permafrost soils at different layer depths, which could be ascribed to the erosion of soil particles or leaching solution from the thawing permafrost soils to lakes and/or enhanced vegetation growth at the lake bottom. This research highlights the necessity of explicitly considering the thaw lake SOC stocks in Earth system models for more comprehensive future projections of the carbon dynamics on the plateau.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1635/053.166.0118", "year": 2020, "title": "Deciphering the many maps of the Xingu River Basin\u2013an assessment of land cover classifications at multiple scales", "abstract": "Remote sensing is an invaluable tool to objectively illustrate the rapid decline in habitat extents worldwide. The many operational Earth Observation platforms provide options for the generation of land cover maps, each with unique characteristics and considerable semantic differences in the definition of classes. As a result, differences in baseline estimates are inevitable. Here we compare forest cover and surface water estimates over four time periods spanning three decades (19892018) for 1.3 million km2 encompassing the Xingu River Basin, Brazil, from published, freely accessible remotely sensed land cover classifications. While all showed a decrease in forest extent over time, the total deforested area reported by each ranged widely for all time periods. The greatest differences ranged from 9% to 17% (116,958 to 219,778 km2) deforestation of the total area for year 2000 and 20142018 time period, respectively. We also show the high sensitivity of forest fragmentation metrics (entropy and foreground area density) to data quality and spatial resolution, with cloud cover and sensor artefacts resulting in errors. Surface water classifications must be chosen carefully because sources differ greatly in location and mapped area of surface water. After operationalization of the Belo Monte dam complex, the large reservoirs are notably absent from several of the classifications illustrating land cover. Freshwater ecosystem health is influenced by the land cover surrounding water bodies (e.g., riparian zones). Understanding differences between the many remotely sensed baselines is fundamentally important to avoid information misuse, and to objectively choose the most appropriate classification for ecological studies, conservation, or policy making. The differences between the classifications examined here are not a failure of the technology, but due to different interpretations of forest cover and characteristics of the input data (e.g., spatial resolution). Our findings demonstrate the importance of transparency in the generation of remotely sensed classifications and the need for users to familiarize themselves with the characteristics and limitations of each data set.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1080/01431161.2019.1641758", "year": 2019, "title": "Spatio-temporal quality distribution of MODIS vegetation collections 5 and 6: implications for forest-non-forest separability", "abstract": "Moderate Resolution Imaging Spectroradiometer (MODIS) has been employed for continuous monitoring of land surface dynamics to facilitate the examination of spatial aspects of the environment. Periodical generation of MODIS products enables temporal analysis, and the interpretation of temporal patterns requires information about image quality. The MODIS Scientific Data Set (SDS) provides information on image properties. Some research has utilized the SDS to assist in analysis and interpretation, particularly in supporting time series forecasting and estimating invalid data from near-dates observation. Our research compares the usability and reliability information provided in the MODIS SDS for collections 5 and 6 to describe the spatio-temporal distribution of image quality. This research compared the ability of the MODIS collections to identify the extent of water and to differentiate forest from non-forest. Four sites representing tropical and temperate regions were selected in Brazil, Congo, Colorado (United States of America), and the European Alps. The robustness of usability and reliability information for assessing MODIS vegetation collections 5 and 6 was compared over these sites by using 16-day composite products over a year of observations (2015). The spatio-temporal distribution of invalid pixels and gaps derived from usability and reliability information were assessed by using TiSeG (Time series Generator) and GeoDa. Morans I indicated a large number of invalid pixels and temporal gaps were clustered in a few areas. Collection 6 appears more consistent in the identification of waterbodies, either for inland water or ocean, but the error detection of ice fractions in two tropical sites tends to increase. Masking data by using Quality Assurance (QA)-SDS information improved the separability between forest and non-forest. This research demonstrated that evaluating the quality of image products using the SDS assisted the selection of period and location to better differentiate forest and non-forest. The seasonal fluctuation of separability metrics showed the importance of exploring temporal pattern for better understanding of the dynamics of forest cover.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.CATENA.2018.05.008", "year": 2018, "title": "The spatial distribution of critical wind erosion centers according to the dust event in Hormozgan province (south of Iran)", "abstract": "Wind erosion and its consequent dust storms has become one of the environmental risks in today's world, which has annually caused non-compensable destruction in environment and human health. Since wind erosion is one of the main factors of desertification which could result in dust storms, studying and locating the wind erosion centers in southern parts of Iran is of crucial importance. The aim of this study is to determine the spatial distribution of wind erosion centers associated to local dust event in Hormozgan province (south of Iran). Different factors such as soil features, climate, surface roughness, vegetation cover, topography and the length wind exposure should be investigated for zoning the potential wind erosion regions. Studies showed that many of these factors are relatively uniform for the study region. Therefore, zoning based on all of the above-mentioned factors is not efficient. For this reason, soil texture along with vegetation cover and topography were studied in the current study to zone wind erosion. First, satellite data of soil texture, normalized differential vegetation index (NDVI), and topography were used to address the potential regions of wind erosion in warm and cold periods of the year by ArcGIS. Then, the data of 14 synoptic stations in Hormozgan province were utilized to plot the maps of dust event occurrences. Finally, by combination of the satellite and synoptic data, the map of land sensitivity toward wind erosion was provided, and the obtained results were compared with observations of Forest, Ranges and Watershed Organization (FRWO) of Hormozgan province. The results indicated that there are potential regions for wind erosion and dust sources in the study region. In a way that coastal areas have the highest probability to become wind erosion centers. In this regard, Jask, Bandarabbas and Bandar Lengeh are the first three regions in terms of wind erosion; while Abu Musa has the lowest priority in terms of possessing wind erosion centers. Also, it was revealed that sensitivity to wind erosion and dust storms was higher in warm periods of the year as compared with the cold seasons. The results of this study are in agreement with the observations of FRWO of Hormozgan province. Therefore, desert greening measures and actions to prevent wind erosion can control many of dust storms in the regions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/2017JG004073", "year": 2017, "title": "A Newly Identified Role of the Deciduous Forest Floor in the Timing of Green-Up", "abstract": "Plant phenology studies rarely consider controlling factors other than air temperature. We evaluate here the potential significance of physical and chemical properties of soil (edaphic factors) as additional important controls on phenology. More specifically, we investigate causal connections between satellite-observed green-up dates of small forest watersheds and soil properties in the Adirondack Mountains of New York, USA. Contrary to the findings of previous studies, where edaphic controls of spring phenology were found to be marginal, our analyses show that at least three factors manifest themselves as significant controls of seasonal patterns of variation in vegetated land surfaces observed from remote sensing: (1) thickness of the forest floor, (2) concentration of exchangeable soil potassium, and (3) soil acidity. For example, a thick forest floor appears to delay the onset of green-up. Watersheds with elevated concentrations of potassium are associated with early surface greening. We also found that trees growing in strongly acidified watersheds demonstrate delayed green-up dates. Overall, our work demonstrates that, at the scale of small forest watersheds, edaphic factors can explain a significant percentage of the observed spatial variation in land surface phenology that is comparable to the percentage that can be explained by climatic and landscape factors. We conclude that physical and chemical properties of forest soil play important roles in forest ecosystems as modulators of climatic drivers controlling the rate of spring soil warming and the transition of trees out of winter dormancy.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41598-022-17787-8", "year": 2022, "title": "Abiotic and biotic factors controlling the dynamics of soil respiration in a coastal dune ecosystem in western Japan", "abstract": "In this study, we examined the abiotic and biotic factors controlling the dynamics of soil respiration (Rs) while considering the zonal distribution of plant species in a coastal dune ecosystem in western Japan, based on periodic Rs data and continuous environmental data. We set four measurement plots with different vegetation compositions: plot 1 on bare sand; plot 2 on a cluster of young Vitex rotundifolia seedlings; plot 3 on a mixture of Artemisia capillaris and V. rotundifolia; and plot 4 on the inland boundary between the coastal vegetation zone and a Pinus thunbergii forest. Rs increased exponentially along with the seasonal rise in soil temperature, but summer drought stress markedly decreased Rs in plots 3 and 4. There was a significant positive correlation between the natural logarithm of belowground plant biomass and Rs in autumn. Our findings indicate that the seasonal dynamics of Rs in this coastal dune ecosystem are controlled by abiotic factors (soil temperature and soil moisture), but the response of Rs to drought stress in summer varied among plots that differed in dominant vegetation species. Our findings also indicated that the spatial dynamics of Rs are mainly controlled by the distribution of belowground plant biomass and autotrophic respiration.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS11242949", "year": 2019, "title": "Analysis of groundwater and total water storage changes in Poland using GRACE observations, in-situ data, and various assimilation and climate models", "abstract": "The Gravity Recovery and Climate Experiment (GRACE) observations have provided global observations of total water storage (TWS) changes at monthly intervals for over 15 years, which can be useful for estimating changes in GWS after extracting other water storage components. In this study, we analyzed the TWS and groundwater storage (GWS) variations of the main Polish basins, the Vistula and the Odra, using GRACE observations, in-situ data, GLDAS (Global Land Data Assimilation System) hydrological models, and CMIP5 (the World Climate Research Programmes Coupled Model Intercomparison Project Phase 5) climate data. The research was conducted for the period between September 2006 and October 2015. The TWS data were taken directly from GRACE measurements and also computed from four GLDAS (VIC, CLM, MOSAIC, and NOAH) and six CMIP5 (FGOALS-g2, GFDL-ESM2G, GISS-E2-H, inmcm4, MIROC5, and MPI-ESM-LR) models. The GWS data were obtained by subtracting the model TWS from the GRACE TWS. The resulting GWS values were compared with in-situ well measurements calibrated using porosity coefficients. For each time series, the trends, spectra, amplitudes, and seasonal components were computed and analyzed. The results suggest that in Poland there has been generally no major TWS or GWS depletion. Our results indicate that when comparing TWS values, better compliance with GRACE data was obtained for GLDAS than for CMIP5 models. However, the GWS analysis showed better consistency of climate models with the well results. The results can contribute toward selection of an appropriate model that, in combination with global GRACE observations, would provide information on groundwater changes in regions with limited or inaccurate ground measurements.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/VZJ2.20163", "year": 2021, "title": "A parametric sensitivity analysis for prioritizing regolith knowledge needs for modeling water transfers in the West African critical zone", "abstract": "Hard rock aquifers (HRAs) in West Africa (WA) are located within a thick regolith layer. The representation of thick tropical regolith in integrated hydrological models lacks consensus on aquifer geometries and parameter ranges. Our main objective was to determine the knowledge requirements on saturated hydraulic conductivity (Ks) to model the critical zone (CZ) of HRAs in WA. A parametric sensitivity analysis with a focus on the representation of the Ks heterogeneity of the regolith was conducted with a critical zone model (Parflow\u2011CLM [Community Land Model]) of the Upper Ou\u00e9m\u00e9 catchment in Benin (14,000 km2) at a 1\u2011 \u00d7 1\u2011km2 resolution. The impact of parameter changes in the near subsurface (0.3\u2011to\u20115\u2011m depth) and in the deeper regolith aquifer (24\u2011 and 48\u2011m maximum depth) was assessed in five modeling experiments. Streamflow was largely dependent on Ks and on clay distribution in the near subsurface and less on the properties of the deeper subsurface. Groundwater table depths and amplitudes were controlled by vegetation and topography as observed on instrumented hillslopes and for Ks within the literature range. Experiments with higher Ks suggested a Ks threshold where dynamics become less determined by one\u2011dimensional vertical and more determined by lateral processes. Such heterogeneity impacts from smaller scales need to be accounted for when hydrological models are upscaled to larger domains (1\u2011 \u00d7 1\u2011km2 resolution or coarser). Our findings highlight the need for a new conceptual approach to represent clay distribution in order to develop catchment\u2011scale CZ models of HRAs in WA that capture the observed processes.Core Ideas Simulated water balance components for a catchment in West Africa were confirmed by observations. Subsurface (0.3\u2011to\u20115\u2011m depth) exerts stronger control on streamflow than deeper regolith. Ks magnitude determines transition from topography\u2011 to recharge\u2011controlled water table dynamics. We identified a limit of Ks where the impact of one\u2011dimensional processes on water table dynamics ceases. A high\u2011permeability fissured zone at the bottom shows little impact on the simulations.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2018EF000937", "year": 2018, "title": "Future Global Soil Respiration Rates Will Swell Despite Regional Decreases in Temperature Sensitivity Caused by Rising Temperature", "abstract": "Between 1960 and 2014, the global soil respiration (RSG) flux increased at a rate of 0.05 Pg C year-1; however, future increase is uncertain due to variations in projected temperature and regional heterogeneity. Regional differences in the sensitivity of soil respiration (RS) to temperature may alter the overall increase in rates of RS because the RS rates of some regions may decelerate while others continue to rise. Using monthly global RS data, we modeled the relationship between RS and temperature for the globe and eight climate regions and estimated RSG between 1961and 2100 using historical (1961-2014) and future (2015-2100) temperature data [Representative Concentration Pathways (RCP2.6 and RCP8.5)]. Importantly, our approach allowed for estimation of regional sensitivity, where respiration rates may peak or decline as temperature rises. Estimated historical RSG increase (0.05 Pg C year-1) was similar to the RSG increase of previous estimates. However, under the RCP8.5 scenario, which estimates approximately 3 \u00b0C of warming globally, the forecasted acceleration of RSG increased to an average of 0.12 Pg C year-1. Under RCP8.5, the temperature sensitivity of RS declined in the arid, winter-dry temperate, and tropic. These regional declines were offset by increased RS sensitivity and fluxes from the boreal and polar regions. In contrast, under RCP2.6 RSG decelerated slightly from current rates. If rising greenhouse gas emission remains unmitigated, future increases in RSG will be much faster than current and historical rates, thereby possibly enhancing future losses of soil carbon and contributing to positive feedback loops of climate change.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.ISPRSJPRS.2020.11.019", "year": 2020, "title": "Land surface phenology as indicator of global terrestrial ecosystem dynamics: A systematic review", "abstract": "Vegetation phenology is considered an important biological indicator in understanding the behaviour of ecosystems and how it responds to environmental cues. Changes in vegetation dynamics have been strongly linked to the variability of climate patterns and may have an important impact on the ecological processes of ecosystems, such as the land surface-atmosphere exchange of water and carbon, energy flows and interaction between different species. Land surface phenology (LSP) is the study of seasonal patterns in plant phenophases based on time series from vegetation indices (VI) or biophysical variables derived from satellite data, and has played an essential role in monitoring the response of terrestrial ecosystems to environmental changes from local to global scales. The goal of this systematic literature review is to provide a detailed synthesis of the main contributions of the global LSP research to the development of environmental knowledge and remote sensing science and technology, identifying possible gaps that could be addressed in the coming years. This systematic review found that the number of LSP studies has grown exponentially since the 1980s, although the analysis of phenological metrics or phenometrics derived from satellite data (i.e. proxies for the biological phenophases of plants) has focused specifically on ecosystems located in the mid- and high-altitude in the Northern Hemisphere (e.g. boreal forest/taiga, evergreen, deciduous or mixed temperate forest). LSP studies use different satellite dataset and methods to estimate phenometrics. These studies identified an advance in spring and a delay in autumn phenophases as general trends. Although these trends were associated mainly to changes in temperature and precipitation, phenological cycle dynamics might be related to other drivers, such as photoperiod, soil moisture or organic carbon content, among others. Therefore, this interaction between different climatic and non-climatic drivers make phenology modelling a difficult task. Hence, in the coming years, a greater integration of LSP data into ecological process modelling could provide a more complete overview on the terrestrial ecosystems functioning. Furthermore, different technical and methodological aspects (e.g. greater temporal coverage of recent high-spatial-resolution satellites, advances in remote-sensing technology or improved efficiency in the computational processing of geospatial data) may also contribute to improve our understanding of Earths ecosystem dynamics and their environmental drivers.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2021WR031565", "year": 2022, "title": "Leveraging Pre\u2010Storm Soil Moisture Estimates for Enhanced Land Surface Model Calibration in Ungauged Hydrologic Basins", "abstract": "Despite long-standing efforts, hydrologists still lack robust tools for calibrating land surface model (LSM) streamflow estimates within ungauged basins. Using surface soil moisture estimates from the Soil Moisture Active Passive Level 4 Soil Moisture (L4_SM) product, precipitation observations, and streamflow gauge measurements for 617 medium-scale (200-10,000 km2) basins in the contiguous United States, we measure the temporal (Spearman) rank correlation between antecedent (i.e., pre-storm) surface soil moisture (ASM) and the storm-scale runoff coefficient (RC; the fraction of storm-scale precipitation accumulation converted into streamflow). In humid and semi-humid basins, this rank correlation is shown to be sufficiently strong to allow for the substitution of storm-scale RC observations (available only in basins that are both lightly regulated and gauged) with high-quality ASM values (available quasi-globally from L4_SM) in streamflow calibration procedures. Using this principle, we define a new, basin-wise LSM streamflow calibration approach based on L4_SM alone and successfully apply it to identify LSM configurations that produce a high rank correlation with observed RC. However, since the approach cannot detect RC bias, it is less successful in identifying LSM configurations with low mean-absolute error.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1126/SCIENCE.AAA7185", "year": 2016, "title": "Empirical evidence of contrasting soil moisture\u2013precipitation feedbacks across the United States", "abstract": "The effects of rainfall on rainfall\r\n Soil moisture, which is controlled in part by past rainfall, can affect the probability of future rainfall over large areas. This is because the water contained in soils helps determine how sunlight is converted into latent heat (evaporation) and sensible heat (which increases overlying air temperatures). Tuttle and Salvucci used data collected for the contiguous United States over 10 years to study this relationship. The feedback between soil moisture and rainfall is generally positive in the western United States but negative in the east. This regional dependence could be a function of large-scale differences in aridity.\r\n \r\n Science\r\n , this issue p.\r\n 825\r\n \r\n , \r\n Past rainfall can affect the probability of future rainfall over large areas.\r\n , \r\n Soil moisture influences fluxes of heat and moisture originating at the land surface, thus altering atmospheric humidity and temperature profiles. However, empirical and modeling studies disagree on how this affects the propensity for precipitation, mainly owing to the difficulty in establishing causality. We use Granger causality to estimate the relationship between soil moisture and occurrence of subsequent precipitation over the contiguous United States using remotely sensed soil moisture and gauge-based precipitation observations. After removing potential confounding effects of daily persistence, and seasonal and interannual variability in precipitation, we find that soil moisture anomalies significantly influence rainfall probabilities over 38% of the area with a median factor of 13%. The feedback is generally positive in the west and negative in the east, suggesting dependence on regional aridity.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2022.128096", "year": 2022, "title": "Revising precipitation water storages vegetation signatures with GRACE-based data assimilation", "abstract": "The availability of freshwater is highly influenced by climate change, extreme climate events and by anthropogenic use. Countries where a large part of the population depends on the agricultural sector, such as South Africa, are strongly affected by changes in climate, which emphasizes that water is an essential source for food production and drinking water. To analyze changes in surface and subsurface water, model simulations and in situ data are commonly used. However, both have limitations, for example, the models rely on potentially erroneous forcing data and insufficient process representations and the in situ data do not represent the larger-scale weather and climate due to spatial and temporal heterogeneity. This can be mitigated by assimilating remote-sensed satellite data into models. In this research, we build a realistic picture of the water and its propagation (measured between peak times) from fluxes as precipitation, to its way through the storages and its impact on vegetation at the 50 km scale by using observation-based data. The observations are derived from MODIS remote-sensing and integrating GRACE total water storage anomaly (TWSA) observations into a hydrological model via data assimilation. Our objective is to identify shortcomings in model simulations by confronting them with the (synthesized) observations. Moreover, we demonstrate the importance of integrating observations into the models. We base these comparisons on signatures or sub-signals (e.g., temporal lags and annual amplitudes) that we derive via regression analysis, principal component analysis, sensitivity analysis and correlation analysis from the synthetic data and the model output. Our main results show that correlations and signatures in real observations are found weaker as compared to what is simulated in the model, e.g. for the contribution of precipitation to groundwater. Lag times between precipitation and surface and groundwater storage peaks are observed to be longer than in the model. The observed propagation of soil water from storages to vegetation is often shorter than in the model, while for groundwater it is longer. We believe our findings will be highly relevant for modelers; the gained knowledge can be used to improve models. In addition, we feel our study underlines the potential of GRACE assimilation into hydrological models.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ENVSOFT.2022.105467", "year": 2022, "title": "Multi-modal temporal CNNs for live fuel moisture content estimation", "abstract": "Live fuel moisture content (LFMC) is an important environmental indicator used to measure vegetation conditions and monitor for high fire risk conditions. However, LFMC is challenging to measure on a wide scale, thus reliable models for estimating LFMC are needed. Therefore, this paper proposes a new deep learning architecture for LFMC estimation. The architecture comprises an ensemble of temporal convolutional neural networks that learn from year-long time series of meteorological and reflectance data, and a few auxiliary inputs including the climate zone. LFMC estimation models are designed for two training and evaluation scenarios, one for sites where historical LFMC measurements are available (within-site), the other for sites without historical LFMC measurements (out-of-site). The models were trained and evaluated using a large database of LFMC samples measured in the field from 2001 to 2017 and achieved an RMSE of 20.87% for the within-site scenario and 25.36% for the out-of-site scenario.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1109/TGRS.2022.3174807", "year": 2022, "title": "Satellite Retrievals of Probabilistic Freeze-Thaw Conditions from SMAP and AMSR Brightness Temperatures", "abstract": "The freeze-thaw (FT) status of soil regulates ecological and hydrologic processes and is, therefore, a vital component of land surface models. This study utilizes a hidden Markov model (HMM) to retrieve surface FT status from L-band [Soil Moisture Active Passive (SMAP)] and Ka-band [Advanced Microwave Scanning Radiometer (AMSR)] satellite microwave brightness temperatures in cold-constrained lands north of $45 ^\\circ \\textN$ . The HMM, parameterized on a per-gridcell basis such that there are two possible states and emissions probabilities are assumed to be a two-component Gaussian Mixture, produces the posterior probability (a continuous variable between 0 and 1) that the surface is frozen given the radiometer input. HMM classification accuracy, averaged over five core validation networks, is acceptable (Ap > 80%) when judged against in situ air and soil temperature measurements from individual validation sites and is comparable to that of current FT products that produce a discrete state. Patterns in performance across variable land class, open water fraction, and elevation are assessed from 91 sparse network weather stations within 87 gridcells in the domain. The resulting satellite data record provides a continuous variable estimate of the daily probability of frozen conditions over northern land areas experiencing widespread thawing of permafrost and a shrinking frozen season due to global warming.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS13132491", "year": 2021, "title": "An Improved Method for Pan-Tropical Above-Ground Biomass and Canopy", "abstract": "An improved method for retrieving Above-ground Biomass (AGB) and Canopy Height (CH) based on an observable from Cyclone Global Navigation Satellite System (CYGNSS), soil moisture from Soil Moisture Active Passive (SMAP) and location is proposed. The observable derived from CYGNSS is more sensitive to vegetation. The CYGNSS observable, soil moisture and the location are used as the input features of an Artificial Neural Network (ANN) to retrieve AGB and CH. The sensitivity analysis of the CYGNSS observable to target parameters shows that the proposed observable is more sensitive to AGB/CH than the conventional observable. The AGB/CH retrievals of the improved method show that it has better performance than that of the traditional method, especially in the areas with AGB in the range of 0 to100 Mg/ha and CH in the range of 0 to10 m. For AGB retrievals, the root mean square error (RMSE) and correlation coefficient are 64.84 Mg/ha and 0.80 in the range of 0 to 550 Mg/ha. Compared with the traditional method, the RMSE is decreased by 11.63%, while the correlation coefficient is increased by 5.26%. For CH retrievals, the RMSE and correlation coefficient are 5.97 m and 0.83 in the range of 0 to 45 m. The RMSE is decreased by 12.59%, while the correlation coefficient is increased by 5.06%. The analysis of the improved method in different areas shows that the performance of the improved method over the area with high vegetation is better than the area with low vegetation. The results obtained here further strengthens the capability of GNSS-R for global AGB/CH retrievals as well as different land cover areas.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/BG-19-2465-2022", "year": 2022, "title": "Modelling temporal variability of in situ soil water and vegetation isotopes reveals ecohydrological couplings in a riparian willow plot", "abstract": "Abstract. The partitioning of water fluxes in the critical zone is of great interest due to the implications for understanding water cycling and quantifying water availability for various ecosystem services. We used the tracer-aided ecohydrological model EcH2O-iso to use stable water isotopes to help evaluate water, energy, and biomass dynamics at an intensively monitored study plot under two willow trees, a riparian species, in Berlin, Germany. Importantly, we assessed the value of in situ soil and plant water isotope data in helping to quantify xylem water sources and transit times, with coupled estimates of the temporal dynamics and ages of soil and root uptake water. The willows showed high water use through evapotranspiration, with limited percolation of summer precipitation to deeper soil layers due to the dominance of shallow root uptake (>80 % in the upper 10 cm, 70 %78 % transpiration/evapotranspiration). Lower evapotranspiration under grass (52 %55 % transpiration/evapotranspiration) resulted in higher soil moisture storage, greater soil evaporation, and more percolation of soil water. Biomass allocation was predominantly foliage growth (57 % in grass and 78 % in willow). Shallow soil water age under grass was estimated to be similar to under willows (1517 d). Considering potential xylem transit times showed a substantial improvement in the model's capability to simulate xylem isotopic composition and water ages and demonstrates the potential value of using in situ data to aid ecohydrological modelling. Root water uptake was predominately derived from summer precipitation events (56 %) and had an average age of 35 d, with xylem transport times taking at least 6.28.1 d. By evaluating isotope mass balances along with water partitioning, energy budgets, and biomass allocation, the EcH2O-iso model proved a useful tool for assessing water cycling within the critical zone at high temporal resolution, particularly xylem water sources and transport, which are all necessary for short- and long-term assessment of water availability for plant growth.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/IJERPH19137719", "year": 2022, "title": "Land Use and Climate Change Altered the Ecological Quality in the Luanhe River Basin", "abstract": "Monitoring and assessing ecological quality (EQ) can help to understand the status and dynamics of the local ecosystem. Moreover, land use and climate change increase uncertainty in the ecosystem. The Luanhe River Basin (LHRB) is critical to the ecological security of the BeijingTianjinHebei region. To support ecosystem protection in the LHRB, we evaluated the EQ from 2001 to 2020 based on the Remote Sensing Ecological Index (RSEI) with the Google Earth Engine (GEE). Then, we introduced the coefficient of variation, TheilSen analysis, and MannKendall test to quantify the variation and trend of the EQ. The results showed that the EQ in LHRB was relatively good, with 61.08% of the basin rated as good or excellent. The spatial distribution of EQ was low in the north and high in the middle, with strong improvement in the north and serious degradation in the south. The average EQ ranged from 0.58 to 0.64, showing a significant increasing trend. Furthermore, we found that the expansion of construction land has caused degradation of the EQ, whereas climate change likely improved the EQ in the upper and middle reaches of the LHRB. The results could help in understanding the state and trend of the eco-environment in the LHRB and support decision-making in land-use management and climate change.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.RSE.2020.111728", "year": 2020, "title": "Satellite footprint data from OCO-2 and TROPOMI reveal significant spatio-temporal and inter-vegetation type variabilities of solar-induced fluorescence yield in the US \u2026", "abstract": "Solar-induced chlorophyll fluorescence (SIF) measured from space has been increasingly used to quantify plant photosynthesis at regional and global scales. Apparent canopy SIF yield (SIFyield apparent), determined by fluorescence yield (F) and escaping ratio (fesc), together with absorbed photosynthetically active radiation (APAR), is crucial in driving spatio-temporal variability of SIF. While strong linkages between SIFyield apparent and plant physiological responses and canopy structure have been suggested, spatio-temporal variability of SIFyield apparent at regional scale remains largely unclear, which limits our understanding of the spatio-temporal variability of SIF and its relationship with photosynthesis. In this study, we utilized recent SIF data with high spatial resolution from two satellite instruments, OCO-2 and TROPOMI, together with multiple other datasets. We estimated SIFyield apparent across space, time, and different vegetation types in the U.S. Midwest during crop growing season (May to September) from 2015 to 2018. We found that SIFyield apparent of croplands was larger than non-croplands during peak season (JulyAugust). However, SIFyield apparent between corn (C4 crop) and soybean (C3 crop) did not show a significant difference. SIFyield apparent of corn, soybean, forest, and grass/pasture show clear seasonal and spatial patterns. The spatial variability of precipitation during the growing season could explain the overall spatial pattern of SIFyield apparent. Further analysis by decomposing SIFyield apparent into F and fesc using near-infrared reflectance of vegetation (NIRV) suggests that fesc may be the major driver of the observed variability of SIFyield apparent.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.RSASE.2021.100466", "year": 2021, "title": "Disentangling the effects of hydro-climatic factors and land use intensification on wetland vegetation dynamics in the Lower Delta of the Paran\u00e1 River", "abstract": "The non-insular portion of the Lower Delta of the Parana River is part of the largest mosaic of wetlands in Argentina. However, it is being altered by intensification of cattle grazing and the increasingly rapid implementation of water management infrastructure. In this context, studying the relationship between hydro-climatic variables and vegetation growth is urgent to ensure sound management and conservation. To overcome the limitation of high cloud cover in the area which has hampered the construction of regularly spaced high-resolution time series, we implemented the recently developed spatio-temporal vegetation index image fusion model (STVIFM). In order to understand the relationship between vegetation growth and hydro-climatic factors, we performed pixel-wise correlation analyses between the newly synthesized monthly (30m) NDVI time series and hydro-climatic variables. Then, we tested whether water control infrastructure alters these relationships. Based on the accurate performance of STVIFM, we provide quantitative and spatially accurate evidence on the positive, complementary and heterogeneous relationships between vegetation growth, temperature, rainfall and the flood pulse. Our results show that water management infrastructure decouples certain areas from its natural hydrological regime, decreasing water availability and altering vegetation growth dynamics. In this context, urgent action is needed aimed towards implementing land planning measures that consider the natural variability and hydrologic regime of the system while balancing production and conservation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/IJGI9060364", "year": 2020, "title": "An Integrated Approach for Detection and Prediction of Greening", "abstract": "The combined study of vegetation coverage (VC) and land use change provides important scientific guidance for the restoration and protection of arid regions. Taking Hongjian Nur (HJN) Lake in the desert region as a case study, the VC of this area was calculated using a normalized difference vegetation index (NDVI), which is based on a mixed pixel decomposition method. A grey forecasting model (GM) (1, 1) was used to predict future VC. The driving factors of VC and land use change were analyzed. The results indicate that the average VC of the whole watershed showed a gradual increase from 0.29 to 0.49 during 20002017. The prediction results of the GM VC showed that the greening trend is projected to continue until 2027. The area of farmland in the watershed increased significantly and its area was mainly converted from unused land, grassland, and forest. The reason for increased VC may be that the combination of the exploitation of unused land and climate change, which is contrary to the countrys sustainable development goals (SDG; goal 15). Therefore, the particularities of the local ecological environment in Chinas desert area needs to be considered in the development of ecological engineering projects.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/LDR.2633", "year": 2017, "title": "THE RESILIENCE OF ETHIOPIAN CHURCH FORESTS: INTERPRETING AERIAL", "abstract": "Church forests collectively represent the only surviving remnants of the original montane forest, serving as critical sanctuaries for many of Ethiopia's endangered and endemic plant and invertebrate taxa. Modern inventories of church forests suggest that they are vulnerable to degradation because of their small size and isolation. The aim of this study is to use historical air photos from the period of the Italian occupation of Ethiopia (1935\u20131941) to measure changes to church forests over a ~80\u2011year time span. We find little evidence that church forests in the study region around Debra Tabor in the northern Ethiopia highlands are declining in size. Rather, church forests have proven to be remarkably resilient on the landscape despite decades of dramatic change to the world around them. Our findings, therefore, highlight the effectiveness of religion\u2011based forest stewardship. Results also indicate, however, that while many church forests used to be buffered from intensive agricultural activity (e.g., cultivation and pasture) today, they find themselves significantly more isolated and vulnerable to edge effects as a result of a general decrease of trees and bushlands surrounding the forests. Copyright", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/IJGI11080451", "year": 2022, "title": "Assessing Multi-Temporal Global Urban Land-Cover Products Using", "abstract": "In recent years, the availability of multi-temporal global land-cover datasets has meant that they have become a key data source for evaluating land cover in many applications. Due to the high data volume of the multi-temporal land-cover datasets, probability sampling is an efficient method for validating multi-temporal global urban land-cover maps. However, the current accuracy assessment methods often work for a single-epoch dataset, and they are not suitable for multi-temporal data products. Limitations such as repeated sampling and inappropriate sample allocation can lead to inaccurate evaluation results. In this study, we propose the use of spatio-temporal stratified sampling to assess thematic mappings with respect to the temporal changes and spatial clustering. The total number of samples in the two stages, i.e., map and pixel, was obtained by using a probability sampling model. Since the proportion of the area labeled as no change is large while that of the area labeled as change is small, an optimization algorithm for determining the sample sizes of the different strata is proposed by minimizing the sum of variance of the users accuracy, producers accuracy, and proportion of area for all strata. The experimental results show that the allocation of sample size by the proposed method results in the smallest bias in the estimated accuracy, compared with the conventional sample allocation, i.e., equal allocation and proportional allocation. The proposed method was applied to multi-temporal global urban land-cover maps from 2000 to 2010, with a time interval of 5 years. Due to the spatial aggregation characteristics, the local pivotal method (LPM) is adopted to realize spatially balanced sampling, leading to more representative samples for each stratum in the spatial domain. The main contribution of our research is the proposed spatio-temporal sampling approach and the accuracy assessment conducted for the multi-temporal global urban land-cover product.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ECOLMODEL.2016.12.009", "year": 2017, "title": "Environmental accounting for ecosystem conservation: Linking societal and ecosystem metabolisms", "abstract": "This paper proposes an approach to environmental accounting useful for studying the feasibility of socio-economic systems in relation to the external constraints posed by ecological compatibility. The approach is based on a multi-scale analysis of the metabolic pattern of ecosystems and societies and it provides an integrated characterization of the resulting interaction. The text starts with a theoretical part explaining (i) the implicit epistemological revolution implied by the notion of ecosystem metabolism and the fund-flow model developed by Georgescu-Roegen applied to environmental accounting, and (ii) the potentials of this approach to create indicators to assess ecological integrity and environmental impacts. This revolution also makes it possible to carry out a multi-scale integrated assessment of ecosystem and societal metabolisms at the territorial level. In the second part, two applications of this approach using an indicator of the negentropic cost show the possibility to characterize in quantitative and qualitative terms degrees of alteration (crop cultivation, tree plantations) for different biomes (tropical and boreal forests). Also, a case study for land use scenarios has been included. The proposed approach represents an integrated multi-scale tool for the analysis of nature conservation scenarios and strategies.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1098/RSTB.2015.0312", "year": 2016, "title": "Ecosystem services from southern African woodlands and their future under global change", "abstract": "Miombo and mopane woodlands are the dominant land cover in southern Africa. Ecosystem services from these woodlands support the livelihoods of 100 M rural people and 50 M urban dwellers, and others beyond the region. Provisioning services contribute $9 2 billion yr1 to rural livelihoods; 76% of energy used in the region is derived from woodlands; and traded woodfuels have an annual value of $780 M. Woodlands support much of the region's agriculture through transfers of nutrients to fields and shifting cultivation. Woodlands store 1824 PgC carbon, and harbour a unique and diverse flora and fauna that provides spiritual succour and attracts tourists. Longstanding processes that will impact service provision are the expansion of croplands (0.1 M km2; 20002014), harvesting of woodfuels (93 M tonnes yr1) and changing access arrangements. Novel, exogenous changes include large-scale land acquisitions (0.07 M km2; 20002015), climate change and rising CO2. The net ecological response to these changes is poorly constrained, as they act in different directions, and differentially on trees and grasses, leading to uncertainty in future service provision. Land-use change and socio-political dynamics are likely to be dominant forces of change in the short term, but important land-use dynamics remain unquantified.This article is part of the themed issue Tropical grassy biomes: linking ecology, human use and conservation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/978-3-030-33157-3_3", "year": 2020, "title": "Scaling functional traits from leaves to canopies", "abstract": "Abstract\r\n In this chapter, we begin by exploring the relationship between plant functional traits and functional diversity and how this relates to the characterization and monitoring of global plant biodiversity. We then discuss the connection between leaf functional traits and their resulting optical properties (i.e., reflectance, transmittance, and absorption) and how this related to remote sensing (RS) of functional diversity. Building on this, we briefly discuss the history of RS of functional traits using spectroscopy and imaging spectroscopy data. We include a discussion of the key considerations with the use of imaging spectroscopy data for scaling and mapping plant functional traits across diverse landscapes. From here we provide a review of the general methods for scaling and mapping functional traits, including empirical and radiative transfer model (RTM) approaches. We complete the chapter with a discussion of other key considerations, such as field sampling protocols, as well as current caveats and future opportunities.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/ANI11113291", "year": 2021, "title": "Molecular Detection and Characterization of Intestinal and Blood", "abstract": "Wild chimpanzee populations in West Africa (Pan troglodytes verus) have dramatically decreased as a direct consequence of anthropogenic activities and infectious diseases. Little information is currently available on the epidemiology, pathogenic significance, and zoonotic potential of protist species in wild chimpanzees. This study investigates the occurrence and genetic diversity of intestinal and blood protists as well as filariae in faecal samples (n = 234) from wild chimpanzees in the Dindefelo Community Nature Reserve, Senegal. PCR-based results revealed the presence of intestinal potential pathogens (Sarcocystis spp.: 11.5%; Giardia duodenalis: 2.1%; Cryptosporidium hominis: 0.9%), protist of uncertain pathogenicity (Blastocystis sp.: 5.6%), and commensal species (Entamoeba dispar: 18.4%; Troglodytella abrassarti: 5.6%). Entamoeba histolytica, Enterocytozoon bieneusi, and Balantioides coli were undetected. Blood protists including Plasmodium malariae (0.4%), Trypanosoma brucei (1.3%), and Mansonella perstans (9.8%) were also identified. Sanger sequencing analyses revealed host-adapted genetic variants within Blastocystis, but other parasitic pathogens (C. hominis, P. malariae, T. brucei, M. perstans) have zoonotic potential, suggesting that cross-species transmission between wild chimpanzees and humans is possible in areas where both species overlap. Additionally, we explored potential interactions between intestinal/blood protist species and seasonality and climate variables. Chimpanzees seem to play a more complex role on the epidemiology of pathogenic and commensal protist and nematode species than initially anticipated.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.CSR.2020.104219", "year": 2020, "title": "Flow structures over mesophotic coral ecosystems in the eastern Gulf of Mexico", "abstract": "Simultaneous time series of current velocity profiles are used to characterize flow structures over intermediate-depth coral ecosystems in the eastern Gulf of Mexico. Understanding of temporal variability and spatial coherence in flow is necessary to establish connectivity among these ecosystems. Time series were collected at Pulley Ridge (the westernmost site), Northern Dry Tortugas, and Southern Dry Tortugas. Overlapping data spanned the period from March 22, 2013 to June 20, 2015. The strongest currents were approximately 1 m s-1 southeastward at Pulley Ridge. Subtidal velocities from the three sites were decomposed into real-vector, concatenated empirical orthogonal functions (EOFs). Results from EOFs indicated that Mode 1, which explained 63% of the subtidal variance, was roughly in the same direction at each of the three sites. Mode 1 directionality indicated potential interconnectivity between Pulley Ridge and Southern Dry Tortugas, and between Northern Dry Tortugas and Pulley Ridge. Mode 1 also suggested limited to no connectivity between the two Dry Tortugas sites as the flows over the two sites were parallel. Mode 2 explained close to 24% of the variance and showed incoherence among the three sites. Wavelet analysis of EOF coefficients indicated dominance of >1 week variability in this region. Flow variability may be associated with wind forcing and Loop Current variability as confirmed by satellite altimetry. Wind forcing caused part of the intra-monthly (<1 month) periodicity in flows. Sea level in the area of the Loop Current, as derived from EOF application on altimetry data during the period of velocity measurements, was related to Mode 1 of the currents at sub-monthly (>1 month) periods. The relationship was more robust, but inverse, when comparing sea level off the northwestern coast of Cuba to the Mode 1 of the currents. These results characterize physical connectivity among South Florida coral ecosystems and have biophysical implications for coral fish populations.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/EAP.1467", "year": 2017, "title": "From pest data to abundance-based risk maps combining eco-physiological knowledge, weather, and habitat variability", "abstract": "Noxious species, i.e., crop pest or invasive alien species, are major threats to both natural and managed ecosystems. Invasive pests are of special importance, and knowledge about their distribution and abundance is fundamental to minimize economic losses and prioritize management activities. Occurrence models are a common tool used to identify suitable zones and map priority areas (i.e., risk maps) for noxious species management, although they provide a simplified description of species dynamics (i.e., no indication on species density). An alternative is to use abundance models, but translating abundance data into risk maps is often challenging. Here, we describe a general framework for generating abundance\u2011based risk maps using multi\u2011year pest data. We used an extensive data set of 3968 records collected between 2003 and 2013 in Wisconsin during annual surveys of soybean aphid (SBA), an exotic invasive pest in this region. By using an integrative approach, we modelled SBA responses to weather, seasonal, and habitat variability using generalized additive models (GAMs). Our models showed good to excellent performance in predicting SBA occurrence and abundance (TSS = 0.70, AUC = 0.92; R2 = 0.63). We found that temperature, precipitation, and growing degree days were the main drivers of SBA trends. In addition, a significant positive relationship between SBA abundance and the availability of overwintering habitats was observed. Our models showed aphid populations were also sensitive to thresholds associated with high and low temperatures, likely related to physiological tolerances of the insects. Finally, the resulting aphid predictions were integrated using a spatial prioritization algorithm (\"Zonation\") to produce an abundance\u2011based risk map for the state of Wisconsin that emphasized the spatiotemporal consistency and magnitude of past infestation patterns. This abundance\u2011based risk map can provide information on potential foci of pest outbreaks where scouting efforts and prophylactic measures should be concentrated. The approach we took is general, relatively simple, and can be applied to other species, habitats and geographical areas for which species abundance data and biotic and abiotic data are available.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.ECSS.2020.107098", "year": 2021, "title": "Estuarine conditions more than pH modulate the physiological flexibility", "abstract": "Coasts and their marine biota are exposed to major environmental heterogeneity as a consequence of natural drivers and anthropogenic stressors. Here, individuals of the mussel Perumytilus purpuratus from two different geographical populations exposed to contrasting environmental conditions (i.e. estuarine versus open coastal conditions) were used in a reciprocal transplant and a laboratory experiment with the aim of determining the grade of of local adaptation to their native sites, as well as their sensibility to ocean acidification. After characterizing environmentally the coastal habitats, a set of life-history traits and a phenotypic plasticity index were determined for both mussel populations. From the reciprocal transplant experiment, we observed that mussels originally coming from the estuarine habitat exhibited a distinctive performance pattern usually associated with physiological stress (i.e. higher metabolic rates, lower calcification and growth rates) leading to important physiological trade-offs and higher levels of phenotypic plasticity. Alternatively, mussels originating from the open coastal site showed lower physiological phenotypic plasticity suggesting a high grade of local adaptation to their habitat. In addition, both populations responded very similarly to lower pH conditions (i.e. increased metabolic rates with no important effects on growth and calcification, and lower physiological phenotypic plasticity). The study results indicated that overall estuarine conditions more than isolated pH changes would be modulating the performance and the level of phenotypic plasticity of the two P. purpuratus geographical populations studied. Our study also emphasizes the necessity of characterizing phenotypic plasticity under multiple-driver environments to cast more accurate predictions about the susceptibility of marine biota to future climate stressors such as ocean acidification.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2021GL093738", "year": 2021, "title": "Contribution of marine phytoplankton and bacteria to alkalinity: an uncharacterized component", "abstract": "The contributions of phytoplankton and bacteria cells to alkalinity (AT) were measured in seawater samples obtained from 205 locations including the East Sea, the North Pacific Ocean, the Bering Sea, the Chukchi Sea, and the Arctic Ocean. We attributed the differences in AT values measured for unfiltered versus filtered samples to AT components contributed by phytoplankton (retained on a 0.7 \u03bcm filter) and by phytoplankton and bacteria combined (AT\u2212BIO; retained on a 0.45 \u03bcm filter). The AT\u2212BIO values reached 10-19 \u03bcmol kg\u22121 in the East Sea and the North Pacific Ocean, and progressively decreased to a level of 1 \u03bcmol kg\u22121 with distance toward the Arctic Ocean. The study shows that the AT\u2212BIO values are non-negligible in coastal and open ocean environments and need to be considered when assessing the accuracy of carbon parameters calculated using the thermodynamic models that use measured AT as an input parameter.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3389/FMARS.2021.669415", "year": 2021, "title": "Long-Term Trends and Impact of SARS-CoV-2 COVID-19 Lockdown on the Primary Productivity of the North Indian Ocean", "abstract": "COrona VIrus Disease (COVID) 2019 pandemic forced most countries to go into complete lockdown and India went on complete lockdown from 24th March 2020 to 8th June 2020. To understand the possible implications of lockdown, we analyze the long-term distribution of Net Primary Productivity (NPP) in the North Indian Ocean (NIO) and the factors that influence NPP directly and indirectly, for the period 20032019 and 2020 separately. There exists a seasonal cycle in the relationship between Aerosol Optical Depth (AOD), Chlorophyll-a (Chl-a) and NPP in agreement with the seasonal transport of aerosols and dust into these oceanic regions. In Arabian Sea (AS), the highest Chl-a (0.58 mg/m3), NPP (696.57 mg/C/m2/day) and AOD (0.39) are observed in June, July, August, and September (JJAS). Similarly, maximum Chl-a (0.48 mg/m3) and NPP (486.39 mg/C/m2/day) are found in JJAS and AOD (0.27) in March, April, and May (MAM) in Bay of Bengal. The interannual variability of Chl-a and NPP with wind speed and Sea Surface Temperature (SST) is also examined, where the former has a positive and the latter has a negative feedback to NPP. The interannual variability of NPP reveals a decreasing trend in NPP, which is interlinked with the increasing trend in SST and AOD. The analysis of wind, SST, Chl-a, and AOD for the pre-lockdown, lockdown, and post lockdown periods of 2020 is employed to understand the impact of COVID-19 lockdown on NPP. The assessment shows the reduction in AOD, decreased wind speeds, increased SST and reduced NPP during the lockdown period as compared to the pre-lockdown, post-lockdown and climatology. This analysis is expected to help to understand the impact of aerosols on the ocean biogeochemistry, nutrient cycles in the ocean biogeochemical models, and to study the effects of climate change on ocean ecosystems.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.160699", "year": 2023, "title": "Fine-scale dynamics of calcite precipitation in a large hardwater lake", "abstract": "In hardwater lakes, calcite precipitation is an important yet poorly understood process in the lacustrine carbon cycle, in which catchment-derived alkalinity (Alk) is both transformed and translocated. While the physico-chemical conditions supporting the supersaturation of water with respect to calcite are theoretically well described, the magnitude and conditions underlying calcite precipitation at fine temporal and spatial scales are poorly constrained. In this study, we used high frequency, depth-resolved (030 m) data collected over 18 months (June 2019 November 2020) in the deeper basin of Lake Geneva to describe the dynamics of calcite precipitation fluxes at a fine temporal resolution (day to season) and to scale them to carbon fixation by primary production. Calcite precipitation occurred during the warm stratified periods when surface water CO2 concentrations were below atmospheric equilibrium. Seasonally, the extent of Alk loss due to calcite precipitation (i.e., [3042] g C m2) depended upon the level of Alk in surface waters. Moreover, interannual variability in seasonal calcite precipitation depended on the duration of stratification, which determined the volume of the water layer susceptible to calcite precipitation. At finer timescales, calcite precipitation was characterized by marked daily variability with dynamics strongly related to that of planktonic autotrophic metabolism. Increasing daily calcite precipitation rates (i.e., maximum values 9 mmol C m3 d1) coincided with increasing net ecosystem production (NEP) during periods of enhanced water column stability. In these conditions, calcite precipitation could remove as much inorganic carbon from the productive layers as NEP. This study provides mechanistic insights into the conditions driving pelagic calcite precipitation, and quantifies its essential contribution to the coupling of organic and inorganic carbon cycling in lakes.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1371/JOURNAL.PONE.0273897", "year": 2022, "title": "Global change differentially modulates Caribbean coral physiology", "abstract": "Global change driven by anthropogenic carbon emissions is altering ecosystems at unprecedented rates, especially coral reefs, whose symbiosis with algal symbionts is particularly vulnerable to increasing ocean temperatures and altered carbonate chemistry. Here, we assess the physiological responses of three Caribbean coral (animal host + algal symbiont) species from an inshore and offshore reef environment after exposure to simulated ocean warming (28, 31C), acidification (3003290 atm), and the combination of stressors for 93 days. We used multidimensional analyses to assess how a variety of coral physiological parameters respond to ocean acidification and warming. Our results demonstrate reductions in coral health in Siderastrea siderea and Porites astreoides in response to projected ocean acidification, while future warming elicited severe declines in Pseudodiploria strigosa. Offshore S. siderea fragments exhibited higher physiological plasticity than inshore counterparts, suggesting that this offshore population was more susceptible to changing conditions. There were no plasticity differences in P. strigosa and P. astreoides between natal reef environments, however, temperature evoked stronger responses in both species. Interestingly, while each species exhibited unique physiological responses to ocean acidification and warming, when data from all three species are modelled together, convergent stress responses to these conditions are observed, highlighting the overall sensitivities of tropical corals to these stressors. Our results demonstrate that while ocean warming is a severe acute stressor that will have dire consequences for coral reefs globally, chronic exposure to acidification may also impact coral physiology to a greater extent in some species than previously assumed. Further, our study identifies S. siderea and P. astreoides as potential winners on future Caribbean coral reefs due to their resilience under projected global change stressors, while P. strigosa will likely be a loser due to their sensitivity to thermal stress events. Together, these species-specific responses to global change we observe will likely manifest in altered Caribbean reef assemblages in the future.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/DDI.13271", "year": 2021, "title": "Analytical guidelines to increase the value of community science data:", "abstract": "AimEcological data collected by the general public are valuable for addressing a wide range of ecological research and conservation planning, and there has been a rapid increase in the scope and volume of data available. However, data from eBird or other large\u2011scale projects with volunteer observers typically present several challenges that can impede robust ecological inferences. These challenges include spatial bias, variation in effort and species reporting bias.InnovationWe use the example of estimating species distributions with data from eBird, a community science or citizen science (CS) project. We estimate two widely used metrics of species distributions: encounter rate and occupancy probability. For each metric, we critically assess the impact of data processing steps that either degrade or refine the data used in the analyses. CS data density varies widely across the globe, so we also test whether differences in model performance are robust to sample size.Main conclusionsModel performance improved when data processing and analytical methods addressed the challenges arising from CS data; however, the degree of improvement varied with species and data density. The largest gains we observed in model performance were achieved with 1) the use of complete checklists (where observers report all the species they detect and identify, allowing non\u2011detections to be inferred) and 2) the use of covariates describing variation in effort and detectability for each checklist. Occupancy models were more robust to a lack of complete checklists. Improvements in model performance with data refinement were more evident with larger sample sizes. In general, we found that the value of each refinement varied by situation and we encourage researchers to assess the benefits in other scenarios. These approaches will enable researchers to more effectively harness the vast ecological knowledge that exists within CS data for conservation and basic research.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2017JG004241", "year": 2018, "title": "Primary Production and Calcification Rates of Algae-Dominated Reef Flat and Seagrass Communities", "abstract": "Monitoring variability in coral reef primary production and calcification is needed to understand changes over time and between reef systems, which helps separate differences due to natural and/or anthropogenic factors happening now and in the future. This study measured net productivity and calcification for two reef systems at Shark Bay, Heron Reef in the southern Great Barrier Reef and Saipan Lagoon, Commonwealth of the Northern Mariana Islands. Net primary productivity and calcification were strongly correlated for reef flats with an adjusted R2 = 0.66. Night time dissolution occurred at Shark Bay reef flat with an average of \u221212.66 mmol CaCO3 \u00b7 m\u22122 \u00b7 hr\u22121, while calcification increased at night for the Saipan reef flat. For both reef flat sites, net productivity from oxygen flux was much lower than rates calculated from change in dissolved inorganic carbon. This study provided the first baseline estimates of net productivity and calcification for a reef flat and seagrass community in Saipan Lagoon. The seagrass community had the lowest productivity of all sites. However, the high presence of calcareous algae at the site highlights the need for more research on the carbonate chemistry of these habitats. All sites had high net productivity that was most likely associated with the dominant presence of algae.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2022JC019063", "year": 2022, "title": "Oxygen variability in the offshore northern Benguela Upwelling System from glider data", "abstract": "Despite their role in modulating the marine ecosystem, variability and drivers of low-oxygen events in the offshore northern Benguela Upwelling System (BenUS) have been rarely investigated due to the events' episodicity which is difficult to resolve using shipboard measurements. We address this issue using 4 months of high-resolution glider data collected between February and June 2018, 100 km offshore at 18\u00b0S. We find that oxygen (O2) concentrations in the offshore northern Benguela are determined by the subsurface alternation of low-oxygen Angola-derived water and oxygenated water from the south at 100-500 m depth. We observe intermittent hypoxia (O2 < 60 \u03bcmol kg-1) which occurs on average for \u223c30% of the 4 months deployment and is driven by the time-varying subsurface pulses of Angola-derived tropical water. Hypoxic events are rather persistent at depths of 300-450 m, while they are more sporadic and have weekly duration at shallower depths (100-300 m). We find extreme values of hypoxia, with O2 minima of 16 \u03bcmol kg-1, associated with an anticyclonic eddy spinning from the undercurrent flowing on the BenUS shelf and showing no surface signature. Fine-scale patchiness and water mass mixing are associated with cross-frontal stirring by a large anticyclone recirculating tropical water into the northern BenUS. The dominance of physical drivers and their high variability on short time scales reveal a dynamic coupling between Angola and Benguela, calling for long-term and high-resolution measurements and studies focusing on future changes of both tropical O2 minima and lateral fluxes in this region.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/ECOG.05545", "year": 2021, "title": "Testing Bergmann's rule in marine copepods", "abstract": "Macroecological relationships provide insights into rules that govern ecological systems. Bergmann's rule posits that members of the same clade are larger at colder temperatures. Whether temperature drives this relationship is debated because several other potential drivers covary with temperature. We conducted a near\u2011global comparative analysis on marine copepods (97 830 samples, 388 taxa) to test Bergmann's rule, considering other potential drivers. Supporting Bergmann's rule, we found temperature better predicted size than did latitude or oxygen, with body size decreasing by 43.9% across the temperature range (\u20111.7 to 30\u00baC). Body size also decreased by 26.9% across the range in food availability. Our results provide strong support for Bergman's rule in copepods, but emphasises the importance of other drivers in modifying this pattern. As the world warms, smaller copepod species are likely to emerge as 'winners', potentially reducing rates of fisheries production and carbon sequestration.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/BG-18-1203-2021", "year": 2021, "title": "The seasonal phases of an Arctic lagoon reveal the discontinuities of pH variability and CO2 flux at the airsea interface", "abstract": "Abstract. The western Arctic Ocean, including its shelves and coastal habitats, has become a focus in ocean acidification research over the past decade as the colder waters of the region and the reduction of sea ice appear to promote the uptake of excess atmospheric CO2. Due to seasonal sea ice coverage, high-frequency monitoring of pH or other carbonate chemistry parameters is typically limited to infrequent ship-based transects during ice-free summers. This approach has failed to capture year-round nearshore carbonate chemistry dynamics which is modulated by biological metabolism in response to abundant allochthonous organic matter to the narrow shelf of the Beaufort Sea and adjacent regions. The coastline of the Beaufort Sea comprises a series of lagoons that account for > 50 % of the landsea interface. The lagoon ecosystems are novel features that cycle between open and closed phases (i.e., ice-free and ice-covered, respectively). In this study, we collected high-frequency pH, salinity, temperature, and photosynthetically active radiation (PAR) measurements in association with the Beaufort Lagoon Ecosystems Long Term Ecological Research program for an entire calendar year in Kaktovik Lagoon, Alaska, USA, capturing two open-water phases and one closed phase. Hourly pH variability during the open-water phases are some of the fastest rates reported, exceeding 0.4 units. Baseline pH varied substantially between the open phase in 2018 and open phase in 2019 from 7.85 to 8.05, respectively, despite similar hourly rates of change. SalinitypH relationships were mixed during all three phases, displaying no correlation in the 2018 open phase, a negative correlation in the 2018/19 closed phase, and a positive correlation during the 2019 open phase. The high frequency of pH variability could partially be explained by photosynthesisrespiration cycles as correlation coefficients between daily average pH and PAR were 0.46 and 0.64 for 2018 and 2019 open phases, respectively. The estimated annual daily average CO2 efflux (from sea to atmosphere) was 5.9 19.3 mmolm-2d-1, which is converse to the negative influx of CO2 estimated for the coastal Beaufort Sea despite exhibiting extreme variability. Considering the geomorphic differences such as depth and enclosure in Beaufort Sea lagoons, further investigation is needed to assess whether there are periods of the open phase in which lagoons are sources of carbon to the atmosphere, potentially offsetting the predicted sink capacity of the greater Beaufort Sea.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ISPRSJPRS.2018.07.016", "year": 2018, "title": "Improvements of the MODIS Gross Primary Productivity model based on a comprehensive uncertainty assessment over the Brazilian Amazonia", "abstract": "Tropical forests and savannas are responsible for the largest proportion of global Gross Primary Productivity (GPP), a major component of the global carbon cycle. However, there are still deficiencies in the spatial and temporal information of tropical photosynthesis and its relations with environmental controls. The MOD17 product, based on the Light Use Efficiency (LUE) concept, has been updated to provide GPP estimates around the globe. In this research, the MOD17 GPP collections 5.0, 5.5 and 6.0 and their sources of uncertainties were assessed by using measurements of meteorology and eddy covariance GPP from eight flux towers in Brazilian tropical ecosystems, from 2000 to 2006. Results showed that the MOD17 collections tend to overestimate GPP at low productivity sites (bias between 111% and 584%) and underestimate it at high productivity sites (bias between 2% and 18%). Overall, the MOD17 product was not able to capture the GPP seasonality, especially in the equatorial sites. Recalculations of MOD17 GPP using site-specific meteorological data, corrected land use/land cover (LULC) classification, and tower-based LUE parameter showed improvements for some sites. However, the improvements were not sufficient to estimate the GPP seasonality in the equatorial forest sites. The use of a new soil moisture constraint on the LUE, based on the Evaporative Fraction, just showed improvements in water-limited sites. Modifications in the algorithm to account for separate LUE for cloudy and clear sky days presented noticeably improved GPP estimates in the tropical ecosystems investigated, both in magnitude and in seasonality. The results suggest that the high cloudiness makes the diffuse radiation an important factor to be considered in the LUE control, especially over dense forests. Thus, the MOD17 GPP algorithm needs more updates to accurately estimate productivity in tropical ecosystems.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/GEB.13304", "year": 2021, "title": "Effectively and accurately mapping global biodiversity patterns for", "abstract": "AimThe aim was to understand the representativeness and accuracy of expert range maps and to explore alternative methods for mapping species distributions accurately.LocationGlobal.Time periodContemporary.Major taxa studiedTerrestrial vertebrates and Odonata.MethodsWe analysed the biases in 50,768 animal International Union for Conservation of Nature, Global Assessment of Reptile Distributions and BirdLife species maps and assessed the links between these maps and existing political boundaries and various non\u2011ecological boundaries to assess their accuracy for certain types of analyses. We cross\u2011referenced each species map with data from the Global Biodiversity Information Facility to assess whether maps captured the whole range of a species and what percentage of occurrence points fell within the assessed range of the species. In addition, we used a number of different methods to map diversity patterns and compared these with high\u2011resolution models of distribution patterns.ResultsOn average, 20\u201330% of the non\u2011coastal range boundaries of species overlapped with administrative national boundaries. In total, 60% of areas with the highest spatial turnover in species (high densities of species range boundaries marking high levels of shift in the community of species present) occurred at political boundaries, which was especially common in Southeast Asia. Different biases existed for different taxa, with gridded analysis in reptiles, river basins in Odonata (except the Americas) and county boundaries for amphibians in the USA. On average, up to half (25\u201346%) of the recorded range points of species fell outside their mapped distributions. Filtered minimum convex polygons performed better than expert range maps in reproducing modelled diversity patterns.Main conclusionsExpert range maps showed high bias at administrative borders in all taxa, but this was highest at the transition from tropical to subtropical regions. The methods used were inconsistent across space, time and taxa, and the ranges mapped did not match species distribution data. Alternative approaches can reconstruct patterns of distribution better than expert maps, and data\u2011driven approaches are needed to provide reliable alternatives to gain a better understanding of species distributions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/ECE3.3569", "year": 2017, "title": "Energy determines broad pattern of plant distribution in Western Himalaya", "abstract": "Several factors describe the broad pattern of diversity in plant species distribution. We explore these determinants of species richness in Western Himalayas using high\u2011resolution species data available for the area to energy, water, physiography and anthropogenic disturbance. The floral data involves 1279 species from 1178 spatial locations and 738 sample plots of a national database. We evaluated their correlation with 8\u2011environmental variables, selected on the basis of correlation coefficients and principal component loadings, using both linear (structural equation model) and nonlinear (generalised additive model) techniques. There were 645 genera and 176 families including 815 herbs, 213 shrubs, 190 trees, and 61 lianas. The nonlinear model explained the maximum deviance of 67.4% and showed the dominant contribution of climate on species richness with a 59% share. Energy variables (potential evapotranspiration and temperature seasonality) explained the deviance better than did water variables (aridity index and precipitation of the driest quarter). Temperature seasonality had the maximum impact on the species richness. The structural equation model confirmed the results of the nonlinear model but less efficiently. The mutual influences of the climatic variables were found to affect the predictions of the model significantly. To our knowledge, the 67.4% deviance found in the species richness pattern is one of the highest values reported in mountain studies. Broadly, climate described by water\u2013energy dynamics provides the best explanation for the species richness pattern. Both modeling approaches supported the same conclusion that energy is the best predictor of species richness. The dry and cold conditions of the region account for the dominant contribution of energy on species richness.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2021JG006606", "year": 2022, "title": "Increasing functional diversity in a global land surface model illustrates uncertainties related to parameter simplification", "abstract": "Simulations of the land surface carbon cycle typically compress functional diversity into a small set of plant functional types (PFT), with parameters defined by the average value of measurements of functional traits. In most earth system models, all wild plant life is represented by between five and 14 PFTs and a typical grid cell (\u2248100 \u00d7 100 km) may contain a single PFT. Model logic applied to this coarse representation of ecological functional diversity provides a reasonable proxy for the carbon cycle, but does not capture the non-linear influence of functional traits on productivity. Here we show through simulations using the Energy Exascale Land Surface Model in 15 diverse terrestrial landscapes, that better accounting for functional diversity markedly alters predicted total carbon uptake. The shift in carbon uptake is as great as 30% and 10% in boreal and tropical regions, respectively, when compared to a single PFT parameterized with the trait means. The traits that best predict gross primary production vary based on vegetation phenology, which broadly determines where traits fall within the global distribution. Carbon uptake is more closely associated with specific leaf area for evergreen PFTs and the leaf carbon to nitrogen ratio in deciduous PFTs.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41477-020-0659-6", "year": 2020, "title": "Genomic history and ecology of the geographic spread of rice", "abstract": "Rice (Oryza sativa) is one of the worlds most important food crops, and is comprised largely of japonica and indica subspecies. Here, we reconstruct the history of rice dispersal in Asia using whole-genome sequences of more than 1,400 landraces, coupled with geographic, environmental, archaeobotanical and paleoclimate data. Originating around 9,000 yr ago in the Yangtze Valley, rice diversified into temperate and tropical japonica rice during a global cooling event about 4,200 yr ago. Soon after, tropical japonica rice reached Southeast Asia, where it rapidly diversified, starting about 2,500 yr bp. The history of indica rice dispersal appears more complicated, moving into China around 2,000 yr bp. We also identify extrinsic factors that influence genome diversity, with temperature being a leading abiotic factor. Reconstructing the dispersal history of rice and its climatic correlates may help identify genetic adaptations associated with the spread of a key domesticated species.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ACP-21-831-2021", "year": 2021, "title": "Linking marine phytoplankton emissions, meteorological processes, and downwind particle properties with FLEXPART", "abstract": "Abstract. Marine biogenic particle contributions to atmospheric aerosol concentrations are not well understood though they are important for determining cloud optical and cloud-nucleating properties. Here we examine the relationship between marine aerosol measurements (with satellites and model fields of ocean biology) and meteorological variables during the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES). NAAMES consisted of four field campaigns between November 2015 and April 2018 that aligned with the four major phases of the annual phytoplankton bloom cycle. The FLEXible PARTicle (FLEXPART) Lagrangian particle dispersion model is used to spatiotemporally connect these variables to ship-based aerosol and dimethyl sulfide (DMS) observations. We find that correlations between some aerosol measurements with satellite-measured and modeled variables increase with increasing trajectory length, indicating that biological and meteorological processes over the air mass history are influential for measured particle properties and that using only spatially coincident data would miss correlative connections that are lagged in time. In particular, the marine non-refractory organic aerosol mass correlates with modeled marine net primary production when weighted by 5 d air mass trajectory residence time (r=0.62). This result indicates that non-refractory organic aerosol mass is influenced by biogenic volatile organic compound (VOC) emissions that are typically produced through bacterial degradation of dissolved organic matter, zooplankton grazing on marine phytoplankton, and as a by-product of photosynthesis by phytoplankton stocks during advection into the region. This is further supported by the correlation of non-refractory organic mass with 2 d residence-time-weighted chlorophyll a (r=0.39), a proxy for phytoplankton abundance, and 5 d residence-time-weighted downward shortwave forcing (r=0.58), a requirement for photosynthesis. In contrast, DMS (formed through biological processes in the seawater) and primary marine aerosol (PMA) concentrations showed better correlations with explanatory biological and meteorological variables weighted with shorter air mass residence times, which reflects their localized origin as primary emissions. Aerosol submicron number and mass negatively correlate with sea surface wind speed. The negative correlation is attributed to enhanced PMA concentrations under higher wind speed conditions. We hypothesized that the elevated total particle surface area associated with high PMA concentrations leads to enhanced rates of condensation of VOC oxidation products onto PMA. Given the high deposition velocity of PMA relative to submicron aerosol, PMA can limit the accumulation of secondary aerosol mass. This study provides observational evidence for connections between marine aerosols and underlying ocean biology through complex secondary formation processes, emphasizing the need to consider air mass history in future analyses.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/JMSE11010068", "year": 2023, "title": "Persistency and Surface Convergence Evidenced by Two Maker Buoys in the Great Pacific Garbage Patch", "abstract": "The accumulation of plastic debris on land and coastlines and in waterways and garbage patches is one of the greatest ecological concerns of the 21st century. In that context, the sources and pathways of plastic marine debris (PMD) have been increasingly studied in the past ten years. The purpose of this communication was to analyze, thanks to the tracks of two drifting buoys released in MayJune 2019 in the North-East Pacific, two features encountered within the Great Pacific Garbage Patch (GPGP): a surface convergence, which could lead to the formation of plastic hotspots, and the persistency of the floating material in this area of the ocean. The evolution of the distance between the buoys was compared with the local circulation field divergence, a Lagrangian plastic dispersal model and sea-level anomalies (SLAs). These analyses highlighted the link between the converging behavior of the drifters and a persistent negative velocity divergence as well as a higher than average-encountered modelled plastic surface density (MPSD). The persistence of the material within the GPGP was observed thanks to the trajectory of the longest persisting drifter in comparison with the trajectory of the GPGP center and extent.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1111/ELE.13983", "year": 2022, "title": "Cascading effects of a disease outbreak in a remote protected area", "abstract": "Disease outbreaks induced by humans increasingly threaten wildlife communities worldwide. Like predators, pathogens can be key top\u2011down forces in ecosystems, initiating trophic cascades that may alter food webs. An outbreak of mange in a remote Andean protected area caused a dramatic population decline in a mammalian herbivore (the vicu\u00f1a), creating conditions to test the cascading effects of disease on the ecological community. By comparing a suite of ecological measurements to pre\u2011disease baseline records, we demonstrate that mange restructured tightly linked trophic interactions previously driven by a mammalian predator (the puma). Following the mange outbreak, scavenger (Andean condor) occurrence in the ecosystem declined sharply and plant biomass and cover increased dramatically in predation refuges where herbivory was historically concentrated. The evidence shows that a disease\u2011induced trophic cascade, mediated by vicu\u00f1a density, could supplant the predator\u2011induced trophic cascade, mediated by vicu\u00f1a behaviour, thereby transforming the Andean ecosystem.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/GCB.16121", "year": 2022, "title": "Satellite observations document trends consistent with a boreal forest", "abstract": "AbstractThe boreal forest biome is a major component of Earth's biosphere and climate system that is projected to shift northward due to continued climate change over the coming century. Indicators of a biome shift will likely first be evident along the climatic margins of the boreal forest and include changes in vegetation productivity, mortality, and recruitment, as well as overall vegetation greenness. However, the extent to which a biome shift is already underway remains unclear because of the local nature of most field studies, sparsity of systematic groundbased ecological monitoring, and reliance on coarse resolution satellite observations. Here, we evaluated early indicators of a boreal forest biome shift using four decades of moderate resolution (30 m) satellite observations and biogeoclimatic spatial datasets. Specifically, we quantified interannual trends in annual maximum vegetation greenness using an ensemble of vegetation indices derived from Landsat observations at 100,000 sample sites in areas without signs of recent disturbance. We found vegetation greenness increased (greened) at 38 [29, 42] % and 22 [15, 26] % of sample sites from 1985 to 2019 and 2000 to 2019, whereas vegetation greenness decreased (browned) at 13 [9, 15] % and 15 [13, 19] % of sample sites during these respective periods [95% Monte Carlo confidence intervals]. Greening was thus 3.0 [2.6, 3.5] and 1.5 [0.8, 2.0] times more common than browning and primarily occurred in cold sparsely treed areas with high soil nitrogen and moderate summer warming. Conversely, browning primarily occurred in the climatically warmest margins of both the boreal forest biome and major forest types (e.g., evergreen conifer forests), especially in densely treed areas where summers became warmer and drier. These macroecological trends reflect underlying shifts in vegetation productivity, mortality, and recruitment that are consistent with early stages of a boreal biome shift.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.MARPOLBUL.2020.110944", "year": 2020, "title": "CO2-driven ocean acidification repressed the growth of adult sea urchin Strongylocentrotus intermedius by impairing intestine function", "abstract": "Strongylocentrotus intermedius cultured in the northern Yellow Sea in China was utilized to evaluate the effects of chronic CO2-driven ocean acidification (OA) on adult sea urchins. Based on the projection of the Intergovernmental Panel on Climate Change (IPCC), present natural seawater conditions (pHNBS = 8.10 0.03) and three laboratory-controlled OA conditions (OA1, pHNBS = 0.3 units; OA2, pHNBS = 0.4 units; OA3, pHNBS = 0.5 units) were employed. After 60-day incubation, our results showed that (1) OA significantly repressed the growth of adult S. intermedius; (2) food consumption tended to be decreased with pH decline; (3) intestinal morphology was changed, and activities of intestinal cellulase and lipase were decreased under acidified conditions; (4) expression levels of two immune-related genes (SiTNF14 and SiTGF-) were altered; (5) rate-limiting enzyme activities of the glycolytic pathway and tricarboxylic acid cycle (TAC) were changed in all OA treatments compared to those of controls.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2019PA003766", "year": 2019, "title": "Rapid Loss of CO\n 2\n From the South Pacific Ocean During the Last Glacial Termination", "abstract": "During the termination of the last ice age, atmospheric CO2 rose ~80 ppm, but the origin of this carbon has not been fully resolved. Here we present novel constraints on the patterns and processes of deglacial CO2 release using three marine sediment cores from the southwest Pacific. Carbon isotopes (\u03b413C) and boron to calcium ratios (B/Ca) of benthic foraminiferal calcite provide records of the \u03b413C of total dissolved inorganic carbon (DIC) and carbonate ion concentrations ([CO32\u2212]) in seawater, respectively. Together these properties indicate enhanced storage of respired CO2 between 1.2\u2011 and 2.5\u2011km water depth during the Last Glacial Maximum (19\u201323 thousand years ago, ka). The first major rise in atmospheric CO2 during the last deglaciation, at the time of Heinrich Stadial 1, was accompanied by increases in \u03b413C and [CO32\u2212] at all core depths. The initial increases could be attributed to southward shifted westerly winds driving increased upwelling in the Southern Ocean, sending a signal of enhanced ventilation northward into the Pacific. Our results confirm that southern Pacific interior water masses served as an important reservoir for CO2 during the last glacial period, likely extracted from the atmosphere via the biologic pump. Some abrupt changes in Pacific carbon storage coincide with changes in Southern Ocean pH (Rae et al., 2018, https://doi.org/10.1038/s41586\u2011018\u20110614\u20110), upwelling indicators (Anderson et al., 2009, https://doi.org/10.1126/science.1167441), and pCO2 (Monnin et al., 2001, https://doi.org/10.1126/science.291.5501.112), indicating that portions of the deep Pacific carbon pool can be ventilated rapidly to the atmosphere via the Southern Ocean.Key Points The southwest Pacific Ocean stored more respired CO2 during the Last Glacial Maximum than during the Holocene Carbonate ion concentration of intermediate water initially increases in tandem with inferred early deglacial Southern Ocean upwelling Release of respired CO2 from the interior Pacific Ocean contributed to the deglacial rise in atmospheric CO2", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/GCB.15776", "year": 2021, "title": "Divergent climate change effects on widespread dryland plant communities driven by climatic and ecohydrological gradients", "abstract": "AbstractPlant community response to climate change will be influenced by individual plant responses that emerge from competition for limiting resources that fluctuate through time and vary across space. Projecting these responses requires an approach that integrates environmental conditions and species interactions that result from future climatic variability. Dryland plant communities are being substantially affected by climate change because their structure and function are closely tied to precipitation and temperature, yet impacts vary substantially due to environmental heterogeneity, especially in topographically complex regions. Here, we quantified the effects of climate change on big sagebrush (Artemisia tridentataNutt.) plant communities that span 76 million ha in the western United States. We used an individualbased plant simulation model that represents intra and interspecific competition for water availability, which is represented by a processbased soil water balance model. For dominant plant functional types, we quantified changes in biomass and characterized agreement among 52 future climate scenarios. We then used a multivariate matching algorithm to generate finescale interpolated surfaces of functional type biomass for our study area. Results suggest geographically divergent responses of big sagebrush to climate change (changes in biomass of 20% to +27%), declines in perennial C3grass and perennial forb biomass in most sites, and widespread, consistent, and sometimes large increases in perennial C4grasses. The largest declines in big sagebrush, perennial C3grass and perennial forb biomass were simulated in warm, dry sites. In contrast, we simulated no change or increases in functional type biomass in cold, moist sites. There was high agreement among climate scenarios on climate change impacts to functional type biomass, except for big sagebrush. Collectively, these results suggest divergent responses to warming in moisturelimited versus temperaturelimited sites and potential shifts in the relative importance of some of the dominant functional types that result from competition for limiting resources.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/GCB.14677", "year": 2019, "title": "Effects of 21st-century climate, land use, and disturbances on ecosystem carbon balance in California", "abstract": "AbstractTerrestrial ecosystems are an important sink for atmospheric carbon dioxide (CO2), sequestering ~30% of annual anthropogenic emissions and slowing the rise of atmospheric CO2. However, the future direction and magnitude of the land sink is highly uncertain. We examined how historical and projected changes in climate, land use, and ecosystem disturbances affect the carbon balance of terrestrial ecosystems in California over the period 20012100. We modeled 32 unique scenarios, spanning 4 land use and 2 radiative forcing scenarios as simulated by four global climate models. Between 2001 and 2015, carbon storage in California's terrestrial ecosystems declined by 188.4 Tg C, with a mean annual flux ranging from a source of 89.8 Tg C/year to a sink of 60.1 Tg C/year. The large variability in the magnitude of the state's carbon source/sink was primarily attributable to interannual variability in weather and climate, which affected the rate of carbon uptake in vegetation and the rate of ecosystem respiration. Under nearly all future scenarios, carbon storage in terrestrial ecosystems was projected to decline, with an average loss of 9.4% (432.3 Tg C) by the year 2100 from current stocks. However, uncertainty in the magnitude of carbon loss was high, with individual scenario projections ranging from 916.2 to 121.2 Tg C and was largely driven by differences in future climate conditions projected by climate models. Moving from a high to a low radiative forcing scenario reduced net ecosystem carbon loss by 21% and when combined with reductions in landuse change (i.e., moving from a high to a low landuse scenario), net carbon losses were reduced by 55% on average. However, reconciling large uncertainties associated with the effect of increasing atmospheric CO2 is needed to better constrain models used to establish baseline conditions from which ecosystembased climate mitigation strategies can be evaluated.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/1365-2664.12282", "year": 2014, "title": "The devil is in the dispersers: predictions of landscape connectivity change with demography", "abstract": "Summary Concern about the effects of habitat fragmentation has led to increasing interest in dispersal and connectivity modelling. Most modern techniques for connectivity modelling have resistance surfaces as their foundation. However, resistance surfaces for animal movement are frequently estimated without considering dispersal, despite being the principal natural mechanism by which organisms move between populations. We collected Global Positioning System data over 10 years from 50 African lions Panthera leo (11 male natal dispersers, 20 adult males and 19 adult females) and used a path level analysis to parameterize demographic\u2011specific resistance surfaces for the Kavango Zambezi Transfrontier Conservation Area (KAZA) in Southern Africa. Lion path selection varied according to demographic grouping: adult females were most averse to risky landscapes such as agro\u2011pastoral lands, towns, areas of high human density and highways. Male natal dispersers were the least\u2011risk averse suggesting they are potentially the most prone demographic to human\u2013lion conflict. Adults of both sexes selected bushed grassland and shrubland habitats and avoided woodland. Male natal dispersers displayed the opposite trend suggesting con\u2011specific avoidance and/or suboptimal habitat use. We used the resistance surfaces to calculate factorial least\u2011cost path networks for each demographic\u2011specific resistance surface and present results that show substantial differences between predicted patterns of connectivity for male natal dispersers, adult females and adult males. Synthesis and applications. Resistance surfaces are widely used to create connectivity models, which are promoted for use by conservation managers. Our results suggest that the demographic category used to parameterize resistance surfaces may lead to radically different conclusions about connectivity. Failure to include dispersing individuals when parameterizing resistance surfaces intended for connectivity modelling may lead to erroneous conclusions about connectivity and potentially unsound management strategies. Resistance surfaces are widely used to create connectivity models, which are promoted for use by conservation managers. Our results suggest that the demographic category used to parameterize resistance surfaces may lead to radically different conclusions about connectivity. Failure to include dispersing individuals when parameterizing resistance surfaces intended for connectivity modelling may lead to erroneous conclusions about connectivity and potentially unsound management strategies.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S43247-020-00083-6", "year": 2021, "title": "Direct measurements reveal instabilities and turbulence within large amplitude internal solitary waves beneath the ocean", "abstract": "Internal solitary waves are ubiquitous in coastal regions and marginal seas of the worlds oceans. As the waves shoal shoreward, they lose the energy obtained from ocean tides through globally significant turbulent mixing and dissipation and consequently pump nutrient-rich water to nourish coastal ecosystem. Here we present fine-scale, direct measurements of shoaling internal solitary waves in the South China Sea, which allow for an examination of the physical processes triggering the intensive turbulent mixing in their interior. These are convective breaking in the wave core and the collapse of KelvinHelmholtz billows in the wave rear and lower periphery of the core, often occurring simultaneously. The former takes place when the particle velocity exceeds the waves propagating velocity. The latter is caused by the instability induced by the strong velocity shear overcoming the stratification. The instabilities generate turbulence levels four orders of magnitude larger than that in the open ocean.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/SREP14947", "year": 2015, "title": "Microplastics in Arctic polar waters: the first reported values of particles in surface and sub-surface samples", "abstract": "Plastic, as a form of marine litter, is found in varying quantities and sizes around the globe from surface waters to deep-sea sediments. Identifying patterns of microplastic distribution will benefit an understanding of the scale of their potential effect on the environment and organisms. As sea ice extent is reducing in the Arctic, heightened shipping and fishing activity may increase marine pollution in the area. Microplastics may enter the region following ocean transport and local input, although baseline contamination measurements are still required. Here we present the first study of microplastics in Arctic waters, south and southwest of Svalbard, Norway. Microplastics were found in surface (top 16 cm) and sub-surface (6 m depth) samples using two independent techniques. Origins and pathways bringing microplastic to the Arctic remain unclear. Particle composition (95% fibres) suggests they may either result from the breakdown of larger items (transported over large distances by prevailing currents, or derived from local vessel activity), or input in sewage and wastewater from coastal areas. Concurrent observations of high zooplankton abundance suggest a high probability for marine biota to encounter microplastics and a potential for trophic interactions. Further research is required to understand the effects of microplastic-biota interaction within this productive environment.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1111/JPY.12855", "year": 2019, "title": "The physiological response of marine diatoms to ocean acidification:", "abstract": "Although increasing the pCO2 for diatoms will presumably down\u2011regulate the CO2\u2011concentrating mechanism (CCM) to save energy for growth, different species have been reported to respond differently to ocean acidification (OA). To better understand their growth responses to OA, we acclimated the diatoms Thalassiosira pseudonana, Phaeodactylum tricornutum, and Chaetoceros muelleri to ambient (pCO2 400 \u03bcatm, pH 8.1), carbonated (pCO2 800 \u03bcatm, pH 8.1), acidified (pCO2 400 \u03bcatm, pH 7.8), and OA (pCO2 800 \u03bcatm, pH 7.8) conditions and investigated how seawater pCO2 and pH affect their CCMs, photosynthesis, and respiration both individually and jointly. In all three diatoms, carbonation down\u2011regulated the CCMs, while acidification increased both the photosynthetic carbon fixation rate and the fraction of CO2 as the inorganic carbon source. The positive OA effect on photosynthetic carbon fixation was more pronounced in C. muelleri, which had a relatively lower photosynthetic affinity for CO2, than in either T. pseudonana or P. tricornutum. In response to OA, T. pseudonana increased respiration for active disposal of H+ to maintain its intracellular pH, whereas P. tricornutum and C. muelleri retained their respiration rate but lowered the intracellular pH to maintain the cross\u2011membrane electrochemical gradient for H+ efflux. As the net result of changes in photosynthesis and respiration, growth enhancement to OA of the three diatoms followed the order of C. muelleri > P. tricornutum > T. pseudonana. This study demonstrates that elucidating the separate and joint impacts of increased pCO2 and decreased pH aids the mechanistic understanding of OA effects on diatoms in the future, acidified oceans.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S10530-022-02838-Y", "year": 2022, "title": "The rise and fall of an alien: why the successful colonizer Littorina saxatilis failed to invade the Mediterranean Sea", "abstract": "Understanding what determines range expansion or extinction is crucial to predict the success of biological invaders. We tackled this long-standing question from an unparalleled perspective using the failed expansions in Littorina saxatilis and investigated its present and past habitat suitability in Europe through Ecological Niche Modelling. This intertidal snail is a typically successful Atlantic colonizer and the earliest confirmed alien species in the Mediterranean Sea, where, however, it failed to thrive despite its high dispersal ability and adaptability. We explored the environmental constraints affecting its biogeography, identified potential glacial refugia in Europe that fuelled its post-glacial colonisations and tested whether the current gaps in its distribution are linked to local ecological features. Our results suggested that L. saxatilis is unlikely to be a glacial relict in the Mediterranean basin. Multiple Atlantic glacial refugia occurred in the Last Glacial Maximum, and abiotic environmental features such as salinity and water temperature have influenced the past and current distributions of this snail and limited its invasion of the Mediterranean Sea. The snail showed a significant overlap in geographic space and ecological niche with Carcinus maenas, the Atlantic predator, but distinct from Pachygrapsus marmoratus, the Mediterranean predator, further pointing to Atlantic-like habitat requirements for this species. Abiotic constrains during introduction rather than dispersal abilities have shaped the past and current range of L. saxatilis and help explaining why some invasions have not been successful. Our findings contribute to clarifying the processes constraining or facilitating shifts in species distributions and biological invasions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/CP-18-147-2022", "year": 2022, "title": "Variations in export production, lithogenic sediment transport and iron fertilization in the Pacific sector of the Drake Passage over the past 400 kyr", "abstract": "Abstract. Changes in Southern Ocean export production have broad biogeochemical and climatic implications. Specifically, iron fertilization likely increased subantarctic nutrient utilization and enhanced the efficiency of the biological pump during glacials. However, past export production in the subantarctic southeastern Pacific is poorly documented, and its connection to Fe fertilization, potentially related to Patagonian Ice Sheet dynamics, is unknown. We report biological productivity changes over the past 400 kyr, based on a combination of 230Thxs-normalized and stratigraphy-based mass accumulation rates of biogenic barium, organic carbon, biogenic opal and calcium carbonate as indicators of paleo-export production in a sediment core upstream of the Drake Passage (57.5 S, 70.3 W). In addition, we use fluxes of iron and lithogenic material as proxies for terrigenous input, and thus potential micronutrient supply. Stratigraphy-based mass accumulation rates are strongly influenced by bottom-current dynamics, which result in variable sediment focussing or winnowing at our site. Carbonate is virtually absent in the core, except during peak interglacial intervals of the Holocene, and Marine Isotope Stages (MIS) 5 and 11, likely caused by transient decreases in carbonate dissolution. All other proxies suggest that export production increased during most glacial periods, coinciding with high iron fluxes. Such augmented glacial iron fluxes at the core site were most likely derived from glaciogenic input from the Patagonian Ice Sheet promoting the growth of phytoplankton. Additionally, glacial export production peaks are also consistent with northward shifts of the Subantarctic and Polar Fronts, which positioned our site south of the Subantarctic Front and closer to silicic acid-rich waters of the Polar Frontal Zone. However, glacial export production near the Drake Passage was lower than in the Atlantic and Indian sectors of the Southern Ocean, which may relate to complete consumption of silicic acid in the study area. Our results underline the importance of micro-nutrient fertilization through lateral terrigenous input from South America rather than eolian transport and exemplify the role of frontal shifts and nutrient limitation for past productivity changes in the Pacific entrance to the Drake Passage.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.7717/PEERJ.9449", "year": 2020, "title": "Treating coral bleaching as weather: a framework to validate and", "abstract": "Few coral reefs remain unscathed by mass bleaching over the past several decades, and much of the coral reef science conducted today relates in some way to the causes, consequences, or recovery pathways of bleaching events. Most studies portray a simple cause and effect relationship between anomalously high summer temperatures and bleaching, which is understandable given that bleaching rarely occurs outside these unusually warm times. However, the statistical skill with which temperature captures bleaching is hampered by many false alarms, times when temperatures reached nominal bleaching levels, but bleaching did not occur. While these false alarms are often not included in global bleaching assessments, they offer valuable opportunities to improve predictive skill, and therefore understanding, of coral bleaching events. Here, I show how a statistical framework adopted from weather forecasting can optimize bleaching predictions and validate which environmental factors play a role in bleaching susceptibility. Removing the 1 C above the maximum monthly mean cutoff in the typical degree heating weeks (DHW) definition, adjusting the DHW window from 12 to 9 weeks, using regional-specific DHW thresholds, and including an El Nino threshold already improves the model skill by 45%. Most importantly, this framework enables hypothesis testing of other factors or metrics that may improve our ability to forecast coral bleaching events.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ECOLMODEL.2005.11.022", "year": 2006, "title": "Formulating and parameterizing the allocation of net primary productivity for modeling overmature stands in boreal forest ecosystems", "abstract": "In process-based models of forest ecosystems, carbon allocation is a key process that partitions the net primary productivity (NPP) among different biomass components and thus affects forest growth patterns at different stages of the forest's growth. Common allocation models usually express the carbon allocation as linear or monotonic functions of time. These models are acceptable for a limited growth period, but inadequate for simulating long-term development of a forest. To improve the usefulness of these models and simplify the model structure, we developed an analytical solution to partition NPP that considers the effects of litterfall and growth rate. We derived NPP allocation functions based on functions for the net growth rate (dry mass) and based on empirical growth curves estimated from normal yield tables for northern Ontario, Canada. The improved allocation reflects growth restrictions that arise in overmature stands according to different site classes across landscape. The details of the derivation and parameterization are presented and discussed. We validated the new NPP allocation functions for black spruce ( Picea mariana) in the boreal forest of northern Ontario. The improved NPP allocation simulated the NPP dynamics of forest ecosystems more accurately over the course of stand development, and the results were biologically realistic.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S12224-022-09411-4", "year": 2022, "title": "Assessing the impact of climate change on threatened endemic vascular plants of Argentina", "abstract": "Biodiversity loss due to climate change is one of the most critical current environmental problems. Global warming is causing substantial species-range shifts and local extirpations, especially for species with restricted distribution ranges. Studies of impact of the climate change on species ranges and environmental suitability have become a fundamental tool for evaluating conservation strategies. However, one important limitation of these approaches is that only species with an adequate number of spatially distinct occurrence records can be modelled, generally excluding threatened rare species from the analyses, a situation referred to as the rare species modelling paradox. To overcome this limitation, we analysed the effect of climate change on the richness of threatened endemic plants of Argentina employing a macroecological modelling approach, using three different modelling techniques (generalized linear mixed models GLMM, generalized additive models GAM, and boosted regression trees BRT), four general circulation models, two representative CO2 concentration pathways (RCPs), and two time periods (2050 and 2070). We identified grid cells with the greatest decline in numbers of threatened endemics, determined species composition in these cells and characterized their vulnerability using three indices. A loss of species richness is observed in ca 83% of the cells, and both protected areas and hotspots of threatened species show significant decrease in future species richness. We identified 32 most affected cells under future climatic projections, including a total of 370 threatened endemic species and exhibiting high beta diversity values (high dissimilarity) among most of the cells. Cells with the highest vulnerability were located along the Central Andes of northwestern Argentina, along the Southern Andean Yungas, High Monte and Central Andean Puna ecoregions, and including a total of 118 threatened endemics (15% of those registered for Argentina) with greater representation of Asteraceae, Apocynaceae, Cactaceae and Iridaceae. However, coverage of protected area network is less than 5% for each of these cells. Our results highlight the urgent need for both in situ and ex situ conservation policies and strategies for the vascular flora of Argentina.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/GMD-15-3121-2022", "year": 2022, "title": "Predicting global terrestrial biomes with the LeNet convolutional neural network", "abstract": "Abstract. A biome is a major regional ecological community characterized by distinctive life forms and principal plants. Many empirical schemes such as the Holdridge life zone (HLZ) system have been proposed and implemented to predict the global distribution of terrestrial biomes. Knowledge of physiological climatic limits has been employed to predict biomes, resulting in more precise simulation; however, this requires different sets of physiological limits for different vegetation classification schemes. Here, we demonstrate an accurate and practical method to construct empirical models for biome mapping: a convolutional neural network (CNN) was trained by an observation-based biome map, as well as images depicting air temperature and precipitation. Unlike previous approaches, which require assumption(s) of environmental constrain for each biome, this method automatically extracts non-linear seasonal patterns of climatic variables that are relevant in biome classification. The trained model accurately simulated a global map of current terrestrial biome distribution. Then, the trained model was applied to climate scenarios toward the end of the 21st century, predicting a significant shift in global biome distribution with rapid warming trends. Our results demonstrate that the proposed CNN approach can provide an efficient and objective method to generate preliminary estimations of the impact of climate change on biome distribution. Moreover, we anticipate that our approach could provide a basis for more general implementations to build empirical models of other climate-driven categorical phenomena.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1098/RSOS.201154", "year": 2022, "title": "Connectivity conservation at the crossroads: protected areas versus payments for ecosystem services in conserving connectivity for Colombian carnivores", "abstract": "Protected areas (PAs) constitute one of the main tools for global landscape conservation. Recently, payments for environmental services (PES) have attracted interest from national and regional governments and are becoming one of the leading conservation policy instruments in tropical countries. However, the degree to which areas designated for PES overlap with areas that are critical for maintaining species' landscape connectivity is rarely evaluated. We estimated habitat distributions and connectivity for 16 of the 22 mammalian carnivores occurring in the Caribbean region of Colombia, and identified the overlap between existing PAs and areas identified as being important for connectivity for these species. We also evaluated the potential impact of creation of new PAs versus new PES areas on conserving connectivity for carnivores. Our results show that PAs cover only a minor percentage of the total area that is important for maintaining connectivity (x=26.8%20.2 s.d.). On the other hand, PES, if implemented extensively, could contribute substantially to mammalian carnivores connectivity (x=45.4%12.8 s.d.). However, in a more realistic scenario with limited conservation investment in which fewer areas are set aside, a strategy based on implementing new PAs seems superior to PES. We argue that prioritizing designation of new PAs will be the most efficient means through which to maintain connectivity.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ECOINF.2022.101900", "year": 2022, "title": "A new synergistic approach for Sentinel-1 and PALSAR-2 in a machine learning framework to predict aboveground biomass of a dense mangrove forest", "abstract": "Mangroves are well-recognized for their very high carbon sequestration potential. However, studies on their role in global carbon cycling and climate change are hindered due to lack of operational methodologies to model and map their biophysical properties. This study establishes a robust methodological protocol for aboveground biomass (AGB) estimation using i) field measurements, ii) a generic (in the absence of species-specific) allometric equation, iii) multi-sensor/polarization SAR data and derived variables thereof, and iv) machine learning models; that demonstrated high prediction accuracy (R2 = 0.93) and low uncertainty (mean 3% and median 1.5%) for a mangrove forest. Following stratified random sampling and on-field accessibility criteria, we laid out 314 elementary sampling points of 0.04 ha each at Bhitarkanika wildlife sanctuary (BWS), India and measured circumference at breast height (CBH) and canopy tree height for 18 species. The estimated AGB range of a generic allometric equation was 9474 Mg/ha for BWS, with a major representation of 9347 Mg/ha. We utilized Sentinel-1 and ALOS-2/PALSAR-2 and derived their variables for AGB prediction. Compared to single sensor-based model, we observed higher prediction accuracy for combined sensor data (R2 = 0.63, 0.87, 0.93; RMSE = 66.75, 39.95, 28.35 Mg/ha; MAE = 52.63, 24.21, 19.55 Mg/ha; and Bias = 3.42, 0.22, 2.15 Mg/ha for C, L and C & L bands respectively using a Generalized Additive Model (GAM) over Random Forest (RF), Gradient Boosting Machines (GBM) and Support Vector Regression (SVR). The higher uncertainty pixels represented seasonal grassland and scrubs in the swampy areas and along the fringes of the creeks that experience diurnal tidal fluctuations. This robust methodology can be replicated for AGB estimates in other mangrove ecosystems to meet the operational carbon accounting requirements of various entities.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S00338-022-02309-9", "year": 2022, "title": "Priority coral conservation areas under global warming in the Amami Islands, Southern Japan", "abstract": "Coral reef ecosystems are highly sensitive to climate change. The Amami Islands in Southern Japan were selected as the study area. It is important to select areas that should be given priority for conservation and subsequently direct resources there. The objective of this study was to identify locations with low bleaching potential against future increases in water temperature, as well as high larval recruitment from other areas and high larval supply capacity to other areas based on connectivity. We simulated the coral bleaching rate and larval connectivity under historical (2000s) and future (RCP2.6 and RCP8.5 in the 2090s) climate conditions using a high-resolution (1/30 1/50) future ocean regional projection dataset. From the model simulation, coral bleaching did not occur in most areas in the 2000s. However, the bleaching frequency would increase significantly under RCP8.5 in the 2090s, and it is projected that mass coral bleaching events will occur in more than half of the years of that decade. Larval dispersion simulation shows that some particles released from the Amami Islands remain in the same area. However, fluctuations in both the sink strength and the source strength among the islands were larger than those within each island, and differences in connectivity between scenarios were not apparent. Grid cells that have a low bleaching rate and high potential for a larval sink and source under each scenario were selected. Since our results can identify priority conservation areas, it is important to conduct conservation and/or adaptation strategies according to the specific characteristics of each island.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.159918", "year": 2023, "title": "Seasonal controlling factors of CO2 exchange in a semiarid shrubland in the Chihuahuan Desert, Mexico", "abstract": "The still significant uncertainties associated with the future capacity of terrestrial systems to mitigate climate change are linked to the lack of knowledge of the biotic and abiotic processes that regulate CO2 net ecosystem exchange (NEE) in space/time. Mainly, rates and controls of CO2 exchange from arid ecosystems, despite dominating the global trends in interannual variability of the terrestrial CO2 sink capacity, are probably the most poorly understood of all. We present a study on rates and controls of CO2 exchange measured with the eddy covariance (EC) technique in the Chihuahuan Desert in the Northeast of Mexico, to understand how the environmental controls of the NEE switch throughout the year using a multilevel approach. Since this is a water-limited ecosystem, the hydroecological year, based on the last precipitation and the decay of air temperature, was used to compare the wet (from May 16 to October 30, 2019) and dry (November 1, 2019 to May 15, 2020) seasons' controlling mechanisms, both at diurnal and nocturnal times. Annual NEE was 303.5 g C m2, with a cumulative Reco of 537.7 g C m2 and GPP of 841.3 g C m2. NEE showed radiation, temperature, and soil moisture sensitivity along the day, however, shifts in these controls along the year and between seasons were identified. The winter precipitations during the dry season led to fast C release followed by lagged C uptake. Despite this flux pulse, the ecosystem was a net sink throughout most of the year because the local vegetation is well adapted to grow and uptake C under these arid conditions, even during the dry season. Understanding the controls of the sink-source shifts is relevant since the predictions for future climate include changes in the precipitation patterns.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-21-15589-2021", "year": 2021, "title": "Uncertainties in eddy covariance CO2 fluxes in a semiarid sagebrush ecosystem caused by gap-filling approaches", "abstract": "Abstract. Gap-filling eddy covariance CO2 fluxes is challenging at dryland sites due to small CO2 fluxes. Here, four machine learning (ML) algorithms including artificial neural network (ANN), k-nearest neighbors (KNNs), random forest (RF), and support vector machine (SVM) are employed and evaluated for gap-filling CO2 fluxes over a semiarid sagebrush ecosystem with different lengths of artificial gaps. The ANN and RF algorithms outperform the KNN and SVM in filling gaps ranging from hours to days, with the RF being more time efficient than the ANN. Performances of the ANN and RF are largely degraded for extremely long gaps of 2 months. In addition, our results suggest that there is no need to fill the daytime and nighttime net ecosystem exchange (NEE) gaps separately when using the ANN and RF. With the ANN and RF, the gap-filling-induced uncertainties in the annual NEE at this site are estimated to be within 16 g C m2, whereas the uncertainties by the KNN and SVM can be as large as 27 g C m2. To better fill extremely long gaps of a few months, we test a two-layer gap-filling framework based on the RF. With this framework, the model performance is improved significantly, especially for the nighttime data. Therefore, this approach provides an alternative in filling extremely long gaps to characterize annual carbon budgets and interannual variability in dryland ecosystems.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1371/JOURNAL.PONE.0273670", "year": 2022, "title": "Comparison of species-specific qPCR and metabarcoding methods to detect small pelagic fish distribution from open ocean environmental DNA", "abstract": "Environmental DNA (eDNA) is increasingly used to noninvasively monitor aquatic animals in freshwater and coastal areas. However, the use of eDNA in the open ocean (hereafter referred to OceanDNA) is still limited because of the sparse distribution of eDNA in the open ocean. Small pelagic fish have a large biomass and are widely distributed in the open ocean. We tested the performance of two OceanDNA analysis methodsspecies-specific qPCR (quantitative polymerase chain reaction) and MiFish metabarcoding using universal primersto determine the distribution of small pelagic fish in the open ocean. We focused on six small pelagic fish species (Sardinops melanostictus, Engraulis japonicus, Scomber japonicus, Scomber australasicus, Trachurus japonicus, and Cololabis saira) and selected the Kuroshio Extension area as a testbed, because distribution of the selected species is known to be influenced by the strong frontal structure. The results from OceanDNA methods were compared to those of net sampling to test for consistency. Then, we compared the detection performance in each target fish between the using of qPCR and MiFish methods. A positive correlation was evident between the qPCR and MiFish detection results. In the ranking of the species detection rates and spatial distribution estimations, comparable similarity was observed between results derived from the qPCR and MiFish methods. In contrast, the detection rate using the qPCR method was always higher than that of the MiFish method. Amplification bias on non-target DNA and low sample DNA quantity seemed to partially result in a lower detection rate for the MiFish method; the reason is still unclear. Considering the ability of MiFish to detect large numbers of species and the quantitative nature of qPCR, the combined usage of the two methods to monitor quantitative distribution of small pelagic fish species with information of fish community structures was recommended.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ENVRES.2022.114991", "year": 2023, "title": "High spatial resolution solar-induced chlorophyll fluorescence and its relation to rainfall precipitation across Brazilian ecosystems", "abstract": "The detection of Solar-Induced chlorophyll Fluorescence (SIF) by remote sensing has opened new perspectives on ecosystem studies and other related aspects such as photosynthesis. In general, fluorescence high-resolution studies were limited to proximal sensors, but new approaches were developed to improve SIF resolution by combining OCO-2 with MODIS orbital observations, improving its resolution from 0.5 to 0.05 on a global scale. Using a high-resolution dataset and rainfall data some SIF characteristics of the satellite were studied based across 06 contrasting ecosystems in Brazil: Amazonia, Caatinga, Cerrado, Atlantic Forest, Pampa, and Pantanal, from years 20152018. SIF spatial variability in each biome presented significant spatial variability structures with high R2 values (>0.6, Gaussian models) in all studied years. The rainfall maps were positively and similar related to SIF spatial distribution and were able to explain more than 40% of SIF's spatial variability. The Amazon biome presented the higher SIF values (>0.4 W m2 sr1 m1) and also the higher annual rainfall precipitation (around 2000 mm), while Caatinga had the lowest SIF values and precipitations (<0.1 W m2 sr1 m1, precipitation around 500 mm). The linear relationship of SIF to rainfall across biomes was mostly significant (except in Pantanal) and presented contrasting sensitivities as in Caatinga SIF was mostly affected while in the Amazon, SIF was lesser affected by precipitation events. We believe that the features presented here indicate that SIF could be highly affected by rainfall precipitation changes in some Brazilian biomes. Combining rainfall with SIF allowed us to detect the differences and similarities across Brazil's biomes improving our understanding on how these ecosystems could be affected by climate change and severe weather conditions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1071/MF18309", "year": 2019, "title": "Ecoregions and stream types help us understand ecological variability in Neotropical reference streams", "abstract": "Stream site classification is a fundamental step in defining reference conditions for freshwater bioassessments globally. Landscape regionalisation and stream typology approaches have both been used to determine classes that reduce inherent environmental variation and to show classes with ecological meaning. We evaluated the applicability of ecoregion and stream typology approaches in a river basin located between the Neotropical Savanna and the Atlantic Forest biomes in south-eastern Brazil. We delimited two ecoregions and assessed whether stream types within each ecoregion would further reduce environmental and macroinvertebrate assemblage variability. In addition, we determined indicator taxa for each of the reference condition classes. Our results confirm the importance of defining ecoregions a priori and for using a nested a posteriori stream typology approach for further explaining macroinvertebrate assemblage variation. Geology and natural vegetation physiognomy were the key ecoregion factors likely to influence macroinvertebrate assemblages, and stream dimension attributes best delimited meaningful stream types. Although stream classification is a very important step in any monitoring, management or restoration program, it has been widely neglected in many tropical regions. In this study we demonstrated how it can be conducted to determine macroinvertebrate assemblage potentials even with a relatively limited number of sites.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2022JD037217", "year": 2022, "title": "Evaluation of Environmental Controls on Terrestrial Net Ecosystem Exchange of CO\n 2\n : A Global Perspective From the FLUXNET Sites", "abstract": "Net ecosystem exchange (NEE) of CO2 is a key process modulating carbon exchanges between terrestrial ecosystems and the atmosphere; however, it remains a grand challenge to elucidate how the interactions of NEE with environmental variables vary among ecosystems and climate regimes across timescales. The FLUXNET and AmeriFlux data sets were used to diagnose the environmental controls on NEE. Based on the sites with long-term observations (\u22657 years), the results showed that the couplings between NEE and surrounding environments were stronger at daily and monthly scales than at annual scales, highlighting the temporal dependence of environmental variables influencing NEE. Moreover, the boosted regression tree method was applied to quantify the relative impacts of environmental controls on daily NEE variations. It revealed that leaf area index (LAI) and shortwave radiation (Rs) were the major divers of daily NEE variations at most sites with the average contribution of 35.5% and 27.8%, respectively. Particularly, LAI was the principal control in deciduous broadleaf forested, non-forested, and arid sites, while Rs was the leading factor in evergreen forested sites. Meanwhile, air temperature (Ta), soil water content (SWC), and vapor pressure deficit (VPD) exerted smaller influences with the average contribution of 14.6%, 13.2%, and 8.9%, respectively. The relative impacts of LAI, Rs, SWC, and VPD also varied with aridity index, and mean annual precipitation and Ta. Furthermore, NEE was more sensitive to vegetation dynamics in drier climate regions. This study provides additional understanding of how environmental factors regulate NEE dynamics across diverse land surface and climatic conditions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.DSR2.2020.104782", "year": 2020, "title": "Variability in fin whale (Balaenoptera physalus) occurrence in the Bering Strait and southern Chukchi Sea in relation to environmental factors", "abstract": "Fin whales (Balaenoptera physalus) are common summer visitors to the Pacific Arctic, migrating through the Bering Strait and into the southern Chukchi Sea to feed on seasonally-abundant prey. The abundance and distribution of fin whales in the Chukchi Sea varies from year-to-year, possibly reflecting fluctuating environmental conditions. We hypothesized that fin whale calls were most likely to be detected in years and at sites where productive water masses were present, indicated by low temperatures and high salinities, and where strong northward water and wind velocities, resulting in increased prey advection, were prevalent. Using acoustic recordings from three moored hydrophones in the Bering Strait region from 20092015, we identified fin whale calls during the open-water season (JulyNovember) and investigated potential environmental drivers of interannual variability in fin whale presence. We examined near-surface and near-bottom temperatures (T) and salinities (S), wind and water velocities through the strait, water mass presence as estimated using published T/S boundaries, and satellite-derived sea surface temperatures and sea-ice concentrations. Our results show significant interannual variability in the acoustic presence of fin whales with the greatest detections of calls in years with contrasting environmental conditions (2012 and 2015). Colder temperatures, lower salinities, slower water velocities, and weak southward winds prevailed in 2012 while warmer temperatures, higher salinities, faster water velocities, and moderate southward winds prevailed in 2015. Most detections (96%) were recorded at the mooring site nearest the confluence of the nutrient-rich Anadyr and Bering Shelf water masses, ~35 km north of Bering Strait, indicating that productive water masses may influence the occurrence of fin whales. The disparity in environmental conditions between 2012 and 2015 suggests there may be multiple combinations of environmental factors or other unexamined variables that draw fin whales into the Pacific Arctic.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/GCB.15297", "year": 2020, "title": "Parasitoids indicate major climate\u2010induced shifts in arctic communities", "abstract": "AbstractClimatic impacts are especially pronounced in the Arctic, which as a region is warming twice as fast as the rest of the globe. Here, we investigate how mean climatic conditions and rates of climatic change impact parasitoid insect communities in 16 localities across the Arctic. We focus on parasitoids in a widespread habitat, Dryas heathlands, and describe parasitoid community composition in terms of larval host use (i.e., parasitoid use of herbivorous Lepidoptera vs. pollinating Diptera) and functional groups differing in their closeness of host associations (koinobionts vs. idiobionts). Of the latter, we expect idiobiontsas being less finetuned to host developmentto be generally less tolerant to cold temperatures, since they are confined to attacking hosts pupating and overwintering in relatively exposed locations. To further test our findings, we assess whether similar climatic variables are associated with host abundances in a 22 year time series from Northeast Greenland. We find sites which have experienced a temperature rise in summer while retaining cold winters to be dominated by parasitoids of Lepidoptera, with the reverse being true for the parasitoids of Diptera. The rate of summer temperature rise is further associated with higher levels of herbivory, suggesting higher availability of lepidopteran hosts and changes in ecosystem functioning. We also detect a matching signal over time, as higher summer temperatures, coupled with cold early winter soils, are related to high herbivory by lepidopteran larvae, and to declines in the abundance of dipteran pollinators. Collectively, our results suggest that in parts of the warming Arctic, Dryas is being simultaneously exposed to increased herbivory and reduced pollination. Our findings point to potential drastic and rapid consequences of climate change on multitrophiclevel community structure and on ecosystem functioning and highlight the value of collaborative, systematic sampling effort.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.151508", "year": 2022, "title": "Benefits of satellite XCO2 and newly proposed atmospheric CO2 observation network over India in constraining regional CO2 fluxes", "abstract": "Top-down modeling estimates are among the most reliable information available on the CO2 fluxes of the earth system. The inadequate coverage of CO2 observing stations over the tropical regions adds a limitation to this estimate, especially when the satellite XCO2 is strictly screened for cloud contamination, aerosol, dust, etc. In this study, we investigated the potential benefit of a global ground-based observing station network, 17 newly proposed stations over India, and global satellite XCO2 in reducing the uncertainty of terrestrial biospheric fluxes of Tropical Asia-Eurasia in TransCom cyclo-stationary inversion. The data from selected 80 global ground-based CO2 observation stations, together with two additional stations from India (i.e., Cape Rama and Sinhagad) and satellite XCO2, helps to reduce the temperate Eurasian terrestrial flux uncertainty by 23.8%, 26.4%, and 36.2%, respectively. This further improved to 54.7% by adding the newly proposed stations over India into the inversion. By separating the Indian sub-continent from temperate Eurasia (as inspired by the heterogeneity in the terrestrial ecosystems, prevailing meteorological conditions, and the orography of this vast region), the inversion evinces the capacity of existing CO2 observations to reduce the Indian terrestrial flux uncertainty by 20.5%. The largest benefit (70% reduction of annual mean uncertainty) for estimating Indian terrestrial fluxes could be achieved by combining these global observations with data from the newly proposed stations over India. The existing two stations from India suggest Temperate Eurasia as a mild source of CO2 (0.33 0.57 Pg C yr1), albeit with prominent anthropogenic influences visible in these two stations during the dry seasons. This implies that the proposed new stations should be cautiously placed to avoid such effects. The study also finds that the newly proposed stations over India also have an impact in constraining nearby oceanic CO2 fluxes.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2021GB007032", "year": 2022, "title": "The changing CO2 sink in the western Arctic Ocean from 1994 to 2019", "abstract": "The Arctic Ocean has turned from a perennial ice-covered ocean into a seasonally ice-free ocean in recent decades. Such a shift in the air-ice-sea interface has resulted in substantial changes in the Arctic carbon cycle and related biogeochemical processes. To quantitatively evaluate how the oceanic CO2 sink responds to rapid sea ice loss and to provide a mechanistic explanation, here we examined the air-sea CO2 flux and the regional CO2 sink in the western Arctic Ocean from 1994 to 2019 by two complementary approaches: observation-based estimation and a data-driven box model evaluation. The pCO2 observations and model results showed that summer CO2 uptake significantly increased by about 1.4 \u00b1 0.6 Tg C decade-1 in the Chukchi Sea, primarily due to a longer ice-free period, a larger open area, and an increased primary production. However, no statistically significant increase in CO2 sink was found in the Canada Basin and the Beaufort Sea based on both observations and modeled results. The reduced sea ice coverage in summer in the Canada Basin and the enhanced wind speed in the Beaufort Sea potentially promoted CO2 uptake, which was, however, counteracted by a rapidly decreased air-sea pCO2 gradient therein. Therefore, the current and future Arctic Ocean CO2 uptake trends cannot be sufficiently reflected by the air-sea pCO2 gradient alone because of the sea ice variations and other environmental factors.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2020JC016591", "year": 2021, "title": "Upper Ocean Stratification in the Eastern Pacific during the SPURS\u20102 Field Campaign", "abstract": "The region between a shallow mixed layer and a deep isothermal layer resulting from salinity stratification is called a barrier layer (BL). Since BLs hinder the surface heat and momentum exchange with the ocean subsurface, they play an important role in air sea interaction. Synoptic features and formation of BLs and associated temperature inversions (TIs) in the Eastern Pacific Fresh Pool (EPFP) were investigated using shipboard observations. BLs and TIs were found in the high precipitation EPFP, a frontal transition zone (FTZ) and in the sea surface salinity (SSS) front during a 2016 boreal summer cruise. During a 2017 boreal autumn cruise, BLs and TIs were found from the southern part of the EPFP to the SSS front. The BLs in the SSS front and the FTZ were meridionally displaced from the precipitation maximum during both the 2016 and 2017 cruises. Freshening and cooling by tilting of both the isohalines and isotherms of the SSS front occurred via Ekman and geostrophic flow during both cruises, and also within the EPFP during 2016. The SSS front was a dominant contributor to the density gradient in the horizontal plane. A high dissolved oxygen content observed within BLs confirmed that the surface flow plays an important role in the BL and TI formation through the tilting process. Patchy distribution of freshening and cooling by tilting implies an intermittent BL and TI formation with short time scales.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-20-881-2020", "year": 2020, "title": "Air pollution slows down surface warming over the Tibetan Plateau", "abstract": "Abstract. The Tibetan Plateau (TP) plays a vital role in regional and global climate change. The TP has been undergoing significant surface warming starting from 1850, with an air temperature increase of 1.39 K and surface solar dimming resulting from decreased incident solar radiation. The causes and impacts of solar dimming on surface warming are unclear. In this study, long-term (from 1850 to 2015) surface downward radiation datasets over the TP are developed by integrating 18 Coupled Model Intercomparison Project phase 5 (CMIP5) models and satellite products. The validation results from two ground measurement networks show that the generated downward surface radiation datasets have a higher accuracy than the mean of multiple CMIP5 datasets and the fused datasets of reanalysis and satellite products. After analyzing the generated radiation data with four air temperature datasets, we found that downward shortwave radiation (DSR) remained stable before 1950 and then declined rapidly at a rate of 0.53 W m2 per decade, and that the fastest decrease in DSR occurs in the southeastern TP. Evidence from site measurements, satellite observations, reanalysis, and model simulations suggested that the TP solar dimming was primarily driven by increased anthropogenic aerosols. The TP solar dimming is stronger in summer, at the same time that the increasing magnitude of the surface air temperature is the smallest. The cooling effect of solar dimming offsets surface warming on the TP by 0.800.28 K (48.617.3 %) in summer since 1850. It helps us understand the role of anthropogenic aerosols in climate warming and highlights the need for additional studies to be conducted to quantify the influence of air pollution on regional climate change over the TP.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.MARCHEM.2021.104020", "year": 2021, "title": "Sea surface CO2 fugacity in the southwestern South Atlantic Ocean: An evaluation based on satellite-derived images", "abstract": "The South Atlantic Ocean is historically less sampled than the North Atlantic Ocean. Recent efforts have improved our understanding of the carbonate system variable distribution, mainly on sea surface CO2 fugacity (fCO2). However, these studies have been regionally and temporally restricted. Hence, in this research we developed seasonal algorithms of sea surface fCO2 to investigate the CO2 dynamics along the southwestern South Atlantic Ocean during spring-summer and fall-winter periods. The studied region includes the continental shelf areas of the Abrolhos-Campos Region (an area under the influence of central water upwelling), the South Brazil Bight (a large embayment affected by the mesoscale variability in a westward boundary current), the Southern Brazilian Shelf (a coastal zone influenced by freshwater discharge from continent and water mass entrainment), and offshore waters in the open ocean domain of the southwestern South Atlantic Ocean. Monthly satellite images of sea surface temperature, salinity, and chlorophyll-a, which were concomitantly available from August 2011 to June 2015, were used to reconstruct and evaluate the sea surface fCO2 seasonal field. The predicted fields of sea surface fCO2 enabled an investigation of the main drivers that change this variable over the distinct biogeochemical provinces in the region. As expected, the sea surface temperature was the main driver of seasonal changes in sea surface fCO2, but total dissolved inorganic carbon (DIC) and total alkalinity changes were also relevant, mainly in the biogeochemical provinces under the influence of continental freshwater input or central water upwelling. The latter can play an unpredictable role in CO2 dynamics due to nutrient- and DIC-rich water transport close to the surface. Finally, the use of satellite-derived images is a powerful tool to increase biogeochemical knowledge of relatively undersampled ocean regions, while the development of seasonal sea surface fCO2 algorithms allows a better spatiotemporal comprehension of the CO2 distribution, dynamics, and drivers in the southwestern South Atlantic Ocean a key region for improving the understanding of the global carbon cycle.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JAS-D-20-0172.1", "year": 2020, "title": "Anomalous dynamics of QBO disruptions explained by 1D theory with external triggering", "abstract": "Abstract The quasi-biennial oscillation (QBO) is an alternating, descending pattern of zonal winds in the tropical stratosphere with a period averaging 28 months. The QBO was disrupted in 2016, and arguably again in 2020, by the formation of an anomalous easterly shear zone, and unprecedented stagnation and ascent of shear zones aloft. Several mechanisms have been implicated in causing the 2016 disruption, most notably triggering by horizontal eddy momentum flux divergence, but also anomalous upwelling and wave stress. In this paper, the 1D theory of the QBO is used to show how seemingly disparate features of disruptions follow directly from the dynamics of the QBO response to triggering. The perturbed QBO is interpreted using a heuristic version of the 1D model, which establishes that 1) stagnation of shear zones aloft resulted from wave dissipation in the shear zone formed by the triggering, and 2) ascent of shear zones aloft resulted from climatological upwelling advecting the stagnant shear zones. Obstacles remain in the theory of triggering. In the 1D theory, the phasing of the triggering is key to determining the response, but the dependence on magnitude is less steep. Yet in MERRA-2, there are triggering events only 20% weaker than the 2016 triggering and equal to the 2020 triggering that did not lead to disruptions. Complicating matters further, MERRA-2 has record-large analysis tendencies during the 2016 disruption, reducing confidence in the resolved momentum budget.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S13762-021-03900-3", "year": 2022, "title": "Trend analysis of land surface temperature over Iran based on land cover and topography", "abstract": "The relationship between the features of the land surface and the atmosphere is well identified by its temperature. This parameter is a key tool in investigations of relevant energy equilibrium variations. The purpose of this research is to identify and analyze Land Surface Temperature (LST) variations over Iran using MODIS Aqua data. The modified non-parametric MannKendall test is used for examination of trend significance, and Sens slope is used in the calculation of changes rate and direction. The results demonstrated that environmental factors including land cover and elevation have significant effects on LST trend. For inland waters and swamps, positive daytime trends have occurred during the warm months of the year, and negative nighttime trends have occurred during the cold months. The highest frequency of variation per decade corresponds to that between 5 and + 5 degrees Celsius per decade (C/Decade). The mountainous regions have experienced severe positive daytime variations in the cold months and similar changes in the warm months. The findings also indicate that changes in land cover and use have resulted in LST variations. There have been greater daytime than nighttime such variations, and have occurred at far higher rates for four land covers: the bodies of water, cropland, urban areas, and barren land. The overall results of the research demonstrated that MODIS Aqua LST data are capable of accurately monitoring spatiotemporal variations over Iran.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2020GL087770", "year": 2020, "title": "Wintertime Airborne Measurements of Ice Nucleating Particles in the High Arctic: A Hint to a Marine, Biogenic Source for Ice Nucleating Particles", "abstract": "Ice nucleating particles (INPs) affect the radiative properties of cold clouds. Knowledge concerning their concentration above ground level and their potential sources is scarce. Here we present the first highly temperature resolved ice nucleation spectra of airborne samples from an aircraft campaign during late winter in 2018. Most INP spectra featured low concentration levels (<3 \u00b7 10-4 L-1 at -15\u00b0C). However, we also found INP concentrations of up to 1.8\u00b710-2 L-1 at -15\u00b0C and freezing onsets as high as -7.5\u00b0C for samples mainly from the marine boundary layer. Shape and onset temperature of the ice nucleation spectra of those samples as well as heat sensitivity hint at biogenic INP. Colocated measurements additionally indicate a local marine influence rather than long-range transport. Our results suggest that even in late winter above 80\u00b0N a local marine source for biogenic INP, which can efficiently nucleate ice at high temperatures, is present.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S00382-019-04816-Y", "year": 2019, "title": "Diagnosing the development of seasonal stratification using the potential energy anomaly in the North Pacific", "abstract": "Upper-ocean seasonal stratification (seasonal pycnocline and/or transition layer) is a ubiquitous feature and its vertical structure has large spatial variability. The density stratification regulates the stability of the upper ocean and thus can affect the oceanic response to atmospheric forcing and biogeochemical processes by modulating vertical mixing. In this study, we described the development of the seasonal stratification in terms of the stability of the water column, using the potential energy anomaly (PEA) as a metric based on Argo profiles. PEA budget analysis reveals that over most of the North Pacific, seasonal stratification develops under a vertical one-dimensional energy balance between an increase in PEA (i.e., a strengthening of the stratification) driven by atmospheric buoyancy forcing and a decrease in PEA associated with vertical mixing within the water column. Horizontal advection of PEA plays a significant role in the seasonal development of the stratification only in the regions of the western boundary current and equatorial current system south of 10N. We find that, in addition to the total magnitude of the oceanic buoyancy gain, the balance between compositions of the atmospheric forcing (non-penetrating surface buoyancy forcing and penetrating radiative heating) is also important in explaining regional differences in the development of the seasonal stratification. The vertical diffusivity in the seasonal stratification estimated from the residual of the PEA budget is in the range from 5 105 m2 s1 to 5 104 m2 s1 and shows spatial and seasonal variability associated with local wind forcing.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/NCLIMATE3250", "year": 2017, "title": "Local temperature response to land cover and management change driven by non-radiative processes", "abstract": "Following a land cover and land management change (LCMC), local surface temperature responds to both a change in available energy and a change in the way energy is redistributed by various non-radiative mechanisms. However, the extent to which non-radiative mechanisms contribute to the local direct temperature response for different types of LCMC across the world remains uncertain. Here, we combine extensive records of remote sensing and in situ observation to show that non-radiative mechanisms dominate the local response in most regions for eight of nine common LCMC perturbations. We find that forest cover gains lead to an annual cooling in all regions south of the upper conterminous United States, northern Europe, and Siberiareinforcing the attractiveness of re-/afforestation as a local mitigation and adaptation measure in these regions. Our results affirm the importance of accounting for non-radiative mechanisms when evaluating local land-based mitigation or adaptation policies.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JAS-D-15-0350.1", "year": 2016, "title": "Tropical waves and the quasi-biennial oscillation in a 7-km global climate simulation", "abstract": "Abstract This study investigates tropical waves and their role in driving a quasi-biennial oscillation (QBO)-like signal in stratospheric winds in a global 7-km-horizontal-resolution atmospheric general circulation model. The Nature Run (NR) is a 2-yr global mesoscale simulation of the Goddard Earth Observing System Model, version 5 (GEOS-5). In the tropics, there is evidence that the NR supports a broad range of convectively generated waves. The NR precipitation spectrum resembles the observed spectrum in many aspects, including the preference for westward-propagating waves. However, even with very high horizontal resolution and a healthy population of resolved waves, the zonal force provided by the resolved waves is still too low in the QBO region and parameterized gravity wave drag is the main driver of the NR QBO-like oscillation (NR-QBO). The authors suggest that causes include coarse vertical resolution and excessive dissipation. Nevertheless, the very-high-resolution NR provides an opportunity to analyze the resolved wave forcing of the NR-QBO. In agreement with previous studies, large-scale Kelvin and small-scale waves contribute to the NR-QBO driving in eastward shear zones and small-scale waves dominate the NR-QBO driving in westward shear zones. Waves with zonal wavelength < 1000 km account for up to half of the small-scale (<3300 km) resolved wave forcing in eastward shear zones and up to 70% of the small-scale resolved wave forcing in westward shear zones of the NR-QBO.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-17-13049-2017", "year": 2017, "title": "In situ measurements of cloud microphysics and aerosol over coastal Antarctica during the MAC campaign", "abstract": "Abstract. During austral summer 2015, the Microphysics of Antarctic Clouds (MAC) field campaign collected unique and detailed airborne and ground-based in situ measurements of cloud and aerosol properties over coastal Antarctica and the Weddell Sea. This paper presents the first results from the experiment and discusses the key processes important in this region, which is critical to predicting future climate change. The sampling was predominantly of stratus clouds, at temperatures between 20 and 0 C. These clouds were dominated by supercooled liquid water droplets, which had a median concentration of 113 cm3 and an interquartile range of 86 cm3. Both cloud liquid water content and effective radius increased closer to cloud top. The cloud droplet effective radius increased from 4 2 m near cloud base to 8 3 m near cloud top. Cloud ice particle concentrations were highly variable with the ice tending to occur in small, isolated patches. Below approximately 1000 m, glaciated cloud regions were more common at higher temperatures; however, the clouds were still predominantly liquid throughout. When ice was present at temperatures higher than 10 C, secondary ice production most likely through the HallettMossop mechanism led to ice concentrations 1 to 3 orders of magnitude higher than the number predicted by commonly used primary ice nucleation parameterisations. The drivers of the ice crystal variability are investigated. No clear dependence on the droplet size distribution was found. The source of first ice in the clouds remains uncertain but may include contributions from biogenic particles, blowing snow or other surface ice production mechanisms. The concentration of large aerosols (diameters 0.5 to 1.6 m) decreased with altitude and were depleted in air masses that originated over the Antarctic continent compared to those more heavily influenced by the Southern Ocean and sea ice regions. The dominant aerosol in the region was hygroscopic in nature, with the hygroscopicity parameter having a median value for the campaign of 0.66 (interquartile range of 0.38). This is consistent with other remote marine locations that are dominated by sea salt/sulfate.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/NHESS-22-3585-2022", "year": 2022, "title": "Using high-resolution global climate models from the PRIMAVERA project", "abstract": "Abstract. PRIMAVERA (process-based climate simulation: advances in high-resolution modelling and European climate risk assessments) was a European Union Horizon 2020 project whose primary aim was to generate advanced and well-evaluated high-resolution global climate\nmodel datasets for the benefit of governments, business and society in general. Following consultation with members of the insurance industry, we\nhave used a PRIMAVERA multi-model ensemble to generate a European winter windstorm event set for use in insurance risk analysis, containing\napproximately 1300 years of windstorm data. The data are available at https://doi.org/10.5281/zenodo.6492182. To create the storm footprints for the event set, the storms in the PRIMAVERA models are identified through tracking. A method is developed to\nseparate the winds from storms occurring in the domain at the same time. The wind footprints are bias corrected and converted to 3 s gusts\nonto a uniform grid using quantile mapping. The distribution of the number of model storms per season as a function of estimated loss is consistent\nwith re-analysis, as are the total losses per season, and the additional event set data greatly reduce uncertainty on return period magnitudes. The\nevent set also reproduces the temporally clustered nature of European windstorms. Since the event set is generated from global climate models, it can help to quantify the non-linear relationship between large-scale climate indices\nsuch as the North Atlantic Oscillation (NAO) and windstorm damage. Although we find only a moderate positive correlation between extended winter NAO\nand storm damage in northern European countries (consistent with re-analysis), there is a large change in risk of extreme seasons between negative and positive NAO states. The intensities of the most severe storms in the event set are, however, sensitive to the gust conversion and bias correction method used, so care should be taken when interpreting the expected damages for very long return periods.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2022GL099796", "year": 2022, "title": "Impact of warmer sea surface temperature on the global pattern of intense convection: insights from a global storm resolving model", "abstract": "Intense convection (updrafts exceeding 10 m s-1) plays an essential role in severe weather and Earth's energy balance. Despite its importance, how the global pattern of intense convection changes in response to warmed climates remains unclear, as simulations from traditional climate models are too coarse to simulate intense convection. Here we use a kilometer-scale global storm resolving model (GSRM) and conduct year-long simulations of a control run, forced by analyzed sea surface temperature (SST), and one with a 4 K increase in SST. Comparisons show that the increased SST enhances the frequency of intense convection globally with large spatial and seasonal variations. Changes in the spatial pattern of intense convection are associated with changes in planetary circulation. Increases in the intense convection frequency do not necessarily reflect increases in convective available potential energy. The GSRM results are also compared with previously published traditional climate model projections.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JCLI-D-17-0303.1", "year": 2018, "title": "Seasonal and regional variations of long-term changes in upper-tropospheric jets from reanalyses", "abstract": "Abstract Long-term changes in upper-tropospheric jet latitude, altitude, and strength are assessed for 19802014 using five modern reanalyses: MERRA, MERRA-2, ERA-Interim, JRA-55, and NCEP CFSR. Changes are computed from jet locations evaluated daily at each longitude to analyze regional and seasonal variations. The changes in subtropical and polar (eddy driven) jets are evaluated separately. Good agreement among the reanalyses in many regions and seasons provides confidence in the robustness of the diagnosed trends. Jet shifts show strong regional and seasonal variations, resulting in changes that are not robust in zonal or annual means. Robust changes in the subtropical jet indicate tropical widening over Africa except during Northern Hemisphere (NH) spring, and tropical narrowing over the eastern Pacific in NH winter. The Southern Hemisphere (SH) polar jet shows a robust poleward shift, while the NH polar jet shifts equatorward in most regions/seasons. Both subtropical and polar jet altitudes typically increase; these changes are more robust in the NH than in the SH. Subtropical jet wind speeds have generally increased in winter and decreased in summer, whereas polar jet wind speeds have weakened (strengthened) over Africa and eastern Asia (elsewhere) during winter in both hemispheres. The Asian monsoon has increased in area and appears to have shifted slightly westward toward Africa. The results herein highlight the importance of understanding regional and seasonal variations when quantifying long-term changes in jet locations, the mechanisms for those changes, and their potential human impacts. Comparison of multiple reanalyses is a valuable tool for assessing the robustness of jet changes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/S41467-018-07813-7", "year": 2018, "title": "Emerging negative impact of warming on summer carbon uptake in northern ecosystems", "abstract": "Most studies of the northern hemisphere carbon cycle based on atmospheric CO2 concentration have focused on spring and autumn, but the climate change impact on summer carbon cycle remains unclear. Here we used atmospheric CO2 record from Point Barrow (Alaska) to show that summer CO2 drawdown between July and August, a proxy of summer carbon uptake, is significantly negatively correlated with terrestrial temperature north of 50N interannually during 19792012. However, a refined analysis at the decadal scale reveals strong differences between the earlier (19791995) and later (19962012) periods, with the significant negative correlation only in the later period. This emerging negative temperature response is due to the disappearance of the positive temperature response of summer vegetation activities that prevailed in the earlier period. Our finding, together with the reported weakening temperature control on spring carbon uptake, suggests a diminished positive effect of warming on high-latitude carbon uptake.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1088/1748-9326/AC0661", "year": 2021, "title": "Drivers and projections of global surface temperature anomalies at the", "abstract": "Abstract\r\n \r\n More than half of the worlds population now lives in urban areas, and trends in rural-to-urban migration are expected to continue through the end of the century. Although cities create efficiencies that drive innovation and economic growth, they also alter the local surface energy balance, resulting in urban temperatures that can differ dramatically from surrounding areas. Here we introduce a global 1 km resolution data set of seasonal and diurnal anomalies in urban surface temperatures relative to their rural surroundings. We then use satellite-observable parameters in a simple model informed by the surface energy balance to understand the dominant drivers of present urban heating, the heat-related impacts of projected future urbanization, and the potential for policies to mitigate those damages. At present, urban populations live in areas with daytime surface summer temperatures that are 3.21\r\n \r\n C (3.97, 9.24, 5th95th percentiles) warmer than surrounding rural areas. If the structure of cities remains largely unchanged, city growth is projected to result in additional daytime summer surface temperature heat anomalies of 0.19\r\n \r\n C (0.01, 0.47) in 2100in addition to warming due to climate change. This is projected to raise the urban population living under extreme surface temperatures by approximately 20% compared to current distributions. However we also find a significant potential for mitigation: 82% of all urban areas have below average vegetation and/or surface albedo. Optimizing these would reduce urban daytime summer surface temperatures for the affected populations by an average of 0.81\r\n \r\n C (2.55, 0.05).", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/B978-0-323-85195-4.00006-8", "year": 2021, "title": "Climate risk information as a basis for adaptive spatial planning: A case study from Thailand", "abstract": "Spatial planning has an important role to play in climate change adaptation and disaster risk reduction. Particularly in growing urban regions, cities are expanding into hazard-prone areas and lack of planning is leading to increased vulnerability of people and structures and is exacerbating hazards. Gathering and understanding information about the determinants of climate riskhazard, exposure, and vulnerabilityand how physical climate and environmental changes interact with the human socioeconomic system, is an important basis for spatial planning that reduces risk. Using the case study of the Andaman Coast of Thailand, this paper provides an example of the determinants of climate risk and how they are relevant to spatial planning. The paper highlights the importance of considering not just climate-related hazards but also how human settlements are exposed and vulnerable to these hazards.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/SDATA.2016.130", "year": 2017, "title": "High-resolution African population projections from radiative forcing and socio-economic models, 2000 to 2100", "abstract": "For its fifth assessment report, the Intergovernmental Panel on Climate Change divided future scenario projections (20052100) into two groups: Socio-Economic Pathways (SSPs) and Representative Concentration Pathways (RCPs). Each SSP has country-level urban and rural population projections, while the RCPs are based on radiative forcing caused by greenhouse gases, aerosols and associated land-use change. In order for these projections to be applicable in earth system models, SSP and RCP population projections must be at the same spatial scale. Thus, a gridded population dataset that takes into account both RCP-based urban fractions and SSP-based population projection is needed. To support this need, an annual (20002100) high resolution (approximately 1km at the equator) gridded population dataset conforming to both RCPs (urban land use) and SSPs (population) country level scenario data were created.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1002/2017EF000595", "year": 2017, "title": "Assessment of Coastal Governance for Climate Change Adaptation in Kenya", "abstract": "The coastline of Kenya already experiences effects of climate change, adding to existing pressures such as urbanization. Integrated coastal management (ICM) is increasingly recognized as a key policy response to deal with the multiple challenges facing coastal zones, including climate change. It can create an enabling governance environment for effective local action on climate change by facilitating a structured approach to dealing with coastal issues. It encompasses the actions of a wide range of actors, including local governments close to people and their activities affected by climate change. Functioning ICM also offers opportunities for reducing risks and building resilience. This article applied a modified capitals approach framework (CAF), consisting of five \"capitals,\" to assess the status of county government capacity to respond to climate change within the context of coastal governance in three county governments in Kenya. The baseline was defined in terms of governance relating to the implementation of the interrelated policy systems of ICM and coastal climate change adaptation (CCA). The CAF framework provided a systematic approach to building a governance baseline against which to assess the progress of county governments in responding to climate change. It identified gaps in human capacity, financial resource allocation to adaptation and access to climate change information. Furthermore, it showed that having well-developed institutions, including regulatory frameworks at the national level can facilitate but does not automatically enable adaptation at the county level.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.EPSL.2020.116518", "year": 2020, "title": "Improving the estimate of the secular variation of Greenland ice mass in the recent decades by incorporating a stochastic process", "abstract": "The irregular interannual variations observed in the Greenland ice sheet (GrIS) mass balance can be interpreted as stochastic. These variations often have large amplitudes, and, if not accounted for correctly in the mass change model parameterization, could have profound impacts on the estimate of the secular trend and acceleration. Here we propose a new mass trajectory model that includes both the conventional deterministic components and a stochastic component. This new model simultaneously estimates the secular rate and acceleration, seasonal components, and the stochastic component of mass changes. Simulations show that this new model improves estimates of model parameters, especially accelerations, over the conventional model without stochastic component. Using this new model, we estimate an acceleration of 1.6 1.3 Gt/yr2 in mass change (minus means mass loss) for 2003-2017 using the Gravity Recovery and Climate Experiment (GRACE) data and an acceleration of 1.1 1.3 Gt/yr2 using the modeled surface mass balance plus observed ice discharge. The corresponding rates are estimated to be 288.2 12.7 Gt/yr and 274.9 13.0 Gt/yr. The greatest discrepancies between the new and the conventional model parameter determinations are found in the acceleration estimates, 1.6 Gt/yr2 vs. 7.5 Gt/yr2 from the GRACE data. The estimated accelerations using the new method are apparently smaller than those estimated by other studies in terms of mass loss. Our quantitative analysis elucidates that the acceleration estimate using the conventional method is the lower bound (i.e., 7.5 Gt/yr2 for 20032017) while the acceleration estimated by the new method lies in the middle of the possible ranges. It is also found that these discrepancies between the new and the conventional methods diminish with sufficiently long (>20 yr) observation records.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2022GL100973", "year": 2023, "title": "Link between the time\u2010space behavior of rainfall and 3D dynamical structures of equatorial waves in global convection\u2010permitting simulations", "abstract": "Equatorial waves (EWs) control a considerable portion of tropical rainfall variability but numerical models often struggle to capture them. Increased computing power now enables global simulations with resolved deep convection, which is believed to produce more realistic EWs. Here we identify EWs in global ICON simulations with varying horizontal resolution by (a) filtering rainfall based on space-time spectral analysis and (b) projecting wind and geopotential onto theoretical wave patterns. The simulations demonstrate that Kelvin, mixed-Rossby gravity and equatorial Rossby waves are consistently represented, regardless of model resolution and convective treatment. For smaller-scale inertio-gravity waves, however, explicit convection appears to be a prerequisite. Surprisingly, the associated rainfall signals are not accompanied by corresponding wind patterns but appear to be connected to mesoscale convective systems. This demonstrates the importance of analyzing rainfall and dynamical aspects of EWs jointly for a robust assessment.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JCLI-D-17-0632.1", "year": 2018, "title": "Large-scale environmental conditions related to midsummer extreme rainfall events around Japan in the TRMM region", "abstract": "Abstract The precipitation characteristics of extreme events in August determined from 13 years of satellite data around Japan in the TRMM observation region and their relationship with large-scale environmental conditions are examined. Two types of extreme events, extreme rainfall and extreme convective events, are defined in each analysis grid box using maximum near-surface rainfall and maximum 40-dBZ echo-top height in each event, respectively. There are clear differences in precipitation characteristics between the two types of extreme events. Extreme rainfall events are more organized precipitation systems than the extreme convective events, with relatively lower echo-top heights and very low lightning activity. There are also clear differences in the related environmental conditions, where the environments related to the extreme rainfall events are somewhat convectively stable and very humid in almost the entire troposphere. These facts are consistent with our previous studies and reinforce the importance of warm-rain processes in extremely intense precipitation productions. The environments related to the extreme rainfall events exhibit a zonally extended moist anomaly in the free troposphere from southern China to the east of Japan, indicating that the excessive moisture transported from the west by a large-scale flow may partially play a role in producing environmental conditions favorable for extreme rainfall. On the other hand, the environments related to extreme convective events are not associated with free-tropospheric moisture inflow. The relationships with the tropical cyclones and upper-tropospheric dynamical fields are also examined, and are found to be clearly different between the extreme rainfall events and extreme convective events.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSMA.2021.101796", "year": 2021, "title": "Sea surface pCO2 variability and air-sea CO2 exchange in the coastal Sudanese Red Sea", "abstract": "The dynamics of sea surface pCO2 (pCO2w) and airsea CO2 exchange of the Sudanese coastal Red Sea has for the first time been studied over a full annual cycle (October 2014October 2015) based on semi-continuous measurements from moored autonomous sensors. pCO2w showed a seasonal amplitude of approximately 70 atm, overlaid by a high frequency (3-4 days) signal of around 10 atm. The highest values, of about 440 atm occurred during summer and fall, while the lowest values of about 370 atm occurred during winter. The monthly pCO2w change was primarily driven by temperature, i.e., heating and cooling of the water surface. Additionally, Dissolved Inorganic Carbon (DIC) and Total Alkalinity (AT) contributed significantly to the observed change in pCO2w as a consequence of along-coast advection and upwelling of CO2-rich deep water, and likely biological production, and uptake of atmospheric CO2. The area is a net annual source for atmospheric CO2 of 0.180 0.009 mol CO2 m2 y1. Based on a compilation of historic and our new data, altogether covering the years 1977 to 2015, long term trends of pCO2w were determined for the seasons winterspring (1.75 0.72 atm y1) and summer -fall (180 0.41 atm y1), both weaker than the atmospheric trend (1.96 0.02 atm y1). We are suggesting that the study region has transformed from being a source of CO2 to the atmosphere throughout the year to becoming a sink of CO2 during parts of the year. The long term pCO2w trend was to a large degree driven by increasing DIC, but increasing AT and temperature also played a role.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S00382-022-06260-X", "year": 2022, "title": "Southern Ocean sea ice concentration budgets of five ocean-sea ice reanalyses", "abstract": "In this study, sea ice concentration (SIC) budgets were calculated for five ocean-sea ice reanalyses (CFSR, C-GLORSv7, GLORYS12v1, NEMO-EnKF and ORAS5), in the Southern Ocean and compared with observations. Benefiting from the assimilation of SIC, the reanalysis products display a realistic representation of sea ice extent as well as sea ice area. However, when applying the SIC budget diagnostics to decompose the changes in SIC into contributions from advection, divergence, thermodynamics, deformation and data assimilation, we find that both atmospheric and oceanic forcings and model configurations are significant contributors on the budget differences. For the CFSR, the primary source of deviation compared to other reanalyses is the stronger northward component of ice velocity, which results in stronger sea ice advection and divergence. Anomalous surface currents in the CFSR are proposed to be the main cause of the ice velocity anomaly. Furthermore, twice the mean ice thickness in the CFSR compared to other reanalyses makes it more susceptible to wind and oceanic stresses under Coriolis forces, exacerbating the northward drift of sea ice. The C-GLORSv7, GLORYS12v1 and NEMO-EnKF have some underestimation of the contribution of advection and divergence to changes in SIC in autumn, winter and spring compared to observations, but are more reasonable in summer. ORAS5, although using the same coupled model and atmospheric forcing as C-GLORSv7 and GLORYS12v1, has a more significant underestimation of advection and divergence to changes in SIC compared to these two reanalyses. The results of the SIC budgets of five ocean-sea ice reanalyses in the Southern Ocean suggest that future reanalyses should focus on improving the modelling of sea ice velocities, for example through assimilation of sea ice drift observations.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/JMSE9101048", "year": 2021, "title": "General and Local Characteristics of Current Marine Heatwave in the Red Sea", "abstract": "In the ocean, heat waves are vital climatic extremes that can destroy the ecosystem together with ensuing socioeconomic consequences. Marine heat waves (MHW) recently attracted public interest, as well as scientific researchers, which motivates us to analyze the current heat wave events over the Red Sea and its surrounding sea region (Gulf of Aden). First, a comprehensive evaluation of how the extreme Red Sea surface temperature has been changing is presented using 0.25 daily gridded optimum interpolation sea surface temperature (OISST, V2.1) data from 1982 to 2020. Second, an analysis of the MHWs general behavior using four different metrics over the study area, together with a study of the role of climate variability in MHW characteristics, is presented. Finally, the main spatiotemporal characteristics of MHWs were analyzed based on three different metrics to describe MHWs local features. Over the studied 39 years, the current results showed that the threshold of warm extreme sea surface temperature events (90th percentile) is 30.03 C, providing an additional average thermal restriction to MHW threshold values (this value is changed from one grid to another). The current analysis discovered 28 separate MHW events over the Red+, extending from 1988 to 2020, with the four longest events being chosen as a study case for future investigation. For the effect of climate variability, our results during the chosen study cases prove that ENSO and ISMI do not play a significant role in controlling MHW characteristics (except the MHW intensity, which has a clear relation with ENSO/ISMI) on Red+. Moreover, the chlorophyll concentration decreases more significantly than its climatic values during MHW events, showing the importance of the MHW effect on biological Red Sea features. In general, the MHW intensity and duration exhibit a meridional gradient, which increases from north to south over the Red Sea, unlike the MHW frequency, which decreases meridionally.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S00382-020-05188-4", "year": 2020, "title": "Mid-level clouds over the Sahara in a convection-permitting regional model", "abstract": "The simulation of Saharan mid tropospheric clouds is investigated with the weather research and forecasting (WRF) regional atmospheric model at convection permitting (4 km) horizontal grid-spacing. We identify two potential problems in such simulations: one that affects cloud cover, and another that affects the mean and geographic patterns of both cloud and precipitation. Our simulations show that using a vertical grid typical of GCMs (38 levels) inhibits the formation of Saharan mid-level clouds. In particular, it underestimates the supercooled water content that often resides at the top of these clouds, in favour of ice which falls out of the cloud quickly. When the vertical resolution becomes high enough to allow layers of supercooled water and ice to exist separately, the simulation of the Saharan mid-level clouds improves significantly. Additional improvement is achieved by using realistic high resolution surface albedo, which also shows that low albedo areas favour the formation of mid-level clouds much more than high albedo ones. The simulation of precipitation on the northern edge of the Sahel is also improved with the use of realistic surface albedo. Overall, despite the disagreement of the simulated and the observed clouds, our results show that using increased resolution and realistic surface albedo seems to fully reproduce their observed radiative effect.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2019WR025310", "year": 2019, "title": "A Precipitation Recycling Network to Assess Freshwater Vulnerability: Challenging the Watershed Convention", "abstract": "Water resources and water scarcity are usually regarded as local aspects for which a watershed-based management appears adequate. However, precipitation, as a main source of freshwater, may depend on moisture supplied through land evaporation from outside the watershed. This notion of evaporation as a local \"green water\" supply to precipitation is typically not considered in hydrological water assessments. Here we propose the concept of a watershed precipitation recycling network, which establishes atmospheric pathways and links land surface evaporation as a moisture supply to precipitation, hence contributing to local but also remote freshwater resources. Our results show that up to 74% of summer precipitation over European watersheds depends on moisture supplied from other watersheds, which contradicts the conventional consideration of autarkic watersheds. The proposed network approach illustrates atmospheric pathways and enables the objective assessment of freshwater vulnerability and water scarcity risks under global change. The illustrated watershed interdependence emphasizes the need for global water governance to secure freshwater availability.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1175/WCAS-D-18-0035.1", "year": 2019, "title": "\u201cCan you take the heat?\u201d Heat-induced health symptoms are associated with protective behaviors", "abstract": "Abstract The risks associated with extreme heat are increasing as heat waves become more frequent and severe across larger areas. As people begin to experience heat waves more often and in more places, how will individuals respond? Measuring experience with heat simply as exposure to extreme temperatures may not fully capture how people subjectively experience those temperatures or their varied impacts on human health. These impacts may also influence an individuals response to heat and motivate risk-reduction behaviors. If subjectively experiencing negative health effects from extreme heat promotes protective actions, these effects could be used alongside temperature exposure to more accurately measure extreme heat experience and inform risk prevention and communication strategies according to local community needs. Using a multilevel regression model, this study analyzes georeferenced national survey data to assess whether Americans exposure to extreme heat and experience with its health effects are associated with self-reported protective behaviors. Subjective experience with heat-related health symptoms strongly predicted all reported protective behaviors while measured heat exposure had a much weaker influence. Risk perception was strongly associated with some behaviors. This study focuses particularly on the practice of checking on family, friends, and neighbors during a heat wave, which can be carried out by many people. For this behavior, age, race/ethnicity, gender, and income, along with subjective experience and risk perception, were important predictors. Results suggest that the subjective experience of extreme heat influences health-related behavioral responses and should therefore be considered when designing or improving local heat protection plans.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.5194/ACP-20-5093-2020", "year": 2020, "title": "The effects of cloud\u2013aerosol interaction complexity on simulations of presummer rainfall over southern China", "abstract": "Abstract. Convection-permitting simulations are used to understand the effects of cloudaerosol interactions in a case of heavy rainfall over southern China. The simulations are evaluated using radar observations from the Southern China Monsoon Rainfall Experiment (SCMREX) and remotely sensed estimates of precipitation, clouds and radiation. We focus on the effects of complexity in cloudaerosol interactions, especially the depletion and transport of aerosol material by clouds. In particular, simulations with aerosol concentrations held constant are compared with a fully cloudaerosol-interacting system to investigate the effects of two-way coupling between aerosols and clouds on a line of organised deep convection. It is shown that the cloud processing of aerosols can change the vertical structure of the storm by using up aerosols within the core of line, thereby maintaining a relatively clean environment which propagates with the heaviest rainfall. This induces changes in the statistics of surface rainfall, with a cleaner environment being associated with less-intense but more-frequent rainfall. These effects are shown to be related to a shortening of the timescale for converting cloud droplets to rain as the aerosol number concentration is decreased. The simulations are compared to satellite-derived estimates of surface rainfall, a condensed-water path and the outgoing flux of short-wave radiation. Simulations for fewer aerosol particles outperform the more polluted simulations for surface rainfall but give poorer representations of top-of-atmosphere (TOA) radiation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1109/ICOIACT53268.2021.9564013", "year": 2021, "title": "Utilization of remote sensing data for thermal comfort estimation in the coastal urban of Jakarta", "abstract": "Remote sensing has been completing limitation of meteorological data observed on the station. Meteorological data of temperature and humidity is necessary to estimate thermal comfort. As a coastal urban area, Jakarta has been experiencing rapid urbanization that leads to densely populated and built-up area. The objective of this study is to measure thermal comfort by estimating Discomfort Index. MODIS land surface temperature (LST) used to obtain air temperature. The temperature dew point data was derived from ERA5 climate data. The data was validated by meteorological station data, afterward were computed and classified based on the Thom's discomfort index. Seasonal analysis for thermal comfort was represented by 4 seasonal period included DJF (December, January, February), MAM (March, April, May), JJA (June, July, August), and SON (September, October, November). The results show that discomfort index values were varied by season. Generally, the dry season (JJA) tends to be less discomfort than the rainy season (SON and MAM). JJA is the peak of dry season which is characterized by lower temperature and lower humidity. MAM and SON are the transition season which is characterized by higher temperature and higher humidity.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3389/FMARS.2021.602991", "year": 2021, "title": "Future Changes in Oceanography and Biogeochemistry Along the Canadian", "abstract": "Model projections of ocean circulation and biogeochemistry are used to investigate large scale climate changes under moderate mitigation (RCP 4.5) and high emissions (RCP 8.5) scenarios along the continental shelf of the Canadian Pacific Coast. To reduce computational cost, an approach for dynamical downscaling of climate projections was developed that uses atmospheric climatologies with augmented winds to simulate historical (19862005) and future (20462065) periods separately. The two simulations differ in initial and lateral open boundary conditions. For each simulation, the daily climatology of surface winds in the driving model was augmented with high-frequency variability from an atmospheric reanalysis product. The time-slice approach was able to reproduce the observed climate state for the historical period. Sensitivity tests confirmed that the high frequency wind variability plays an essential role in freshwater distribution in this region. Projections suggest that sea surface temperature will increase by 1.82.4C and surface salinity will decrease between 0.08 and 0.23 depending on whether a moderate or high emissions scenario is used. Stratification increases throughout the region and there is some evidence of nutrient limitation near the surface. Primary production and phytoplankton productivity (chlorophyll) also increase. Density surfaces are relocated deeper in the water column and this change is mainly driven by surface heating and freshening. Changes in saturation state are mainly due to anthropogenic CO\r\n 2\r\n with minor contributions from solubility, remineralization and advection. There is little difference between RCP 4.5 and RCP 8.5 with regard to projections of deoxygenation and acidification. The depths of the aragonite saturation state and the oxygen minimum zone are projected to become shallower by 100 and 75 m respectively. Extreme states of temperature, oxygen and acidification are projected to become more frequent and more extreme, with the frequency of occurrence of\r\n \r\n \r\n \r\n [\r\n \r\n \r\n \r\n \r\n O\r\n \r\n \r\n \r\n 2\r\n \r\n \r\n \r\n ]\r\n \r\n <\r\n 60\r\n \r\n mmol\r\n \r\n \r\n \r\n \r\n m\r\n \r\n \r\n \r\n -\r\n 3\r\n \r\n \r\n \r\n \r\n expected to approximately double under either scenario.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2020JD032557", "year": 2020, "title": "Roles of Sea Surface Temperature Warming and Loss of Arctic Sea Ice in the Enhanced Summer Wetting Trend Over Northeastern Siberia During Recent Decades", "abstract": "The water cycle over middle- to high-latitude regions has experienced rapid changes in recent decades. The sea surface temperature (SST) and Arctic sea ice influence the water cycle over these regions, but the relative roles of SST warming and the loss of Arctic sea ice remain unclear. We identify an enhanced change in the summer (June-August) water cycle over northeastern Siberia (55-70\u00b0N, 100-170\u00b0E) during the last three decades. The driving force of this enhanced wetting trend is investigated using both observations and model simulations. An increasing trend of low-level southerly winds and a decrease in sea-level pressure are observed over northeastern Siberia during summer, leading to stronger lower tropospheric moisture convergence and ascending motion, which favor an increase in precipitation. The wetting trend and the associated atmospheric features are successfully reproduced by an atmospheric model driven by the observed Arctic sea ice concentrations and SSTs, whereas the model driven solely by the Arctic sea ice concentrations simulates a negligible increase in precipitation. This is primarily due to the absence of the stronger southerly winds that transport moisture from the Pacific Ocean. The modeling evidence suggests that SST changes in recent decades have a stronger influence on the intensified precipitation than does sea ice. An atmospheric bridge mechanism links the strengthened southerly winds to an upper-level Rossby wave train originating from the North Atlantic. Another atmospheric simulation forced only by Atlantic SST warming recreates the observed enhanced wetting trend in northeastern Siberia and supports the hypothesized atmospheric bridge mechanism.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2018JD028864", "year": 2018, "title": "Representing Cloud Water Content of Extensive Cloud Systems Over Land", "abstract": "We proposed a method to estimate cloud water content (CWC) over land using satellite-based passive microwave brightness temperatures (TBs) at multiple-kilometer resolutions with land and atmosphere assimilation to overcome the challenges associated with estimating the CWC of broad cloud systems over land. This method enables estimation of broad cloud systems over land using multifrequency TBs, which have different sensitivities to land and cloud, by concurrently optimizing land emissions and CWC estimates from models. Estimated CWC was validated using vertical two-dimensional CloudSat products (2B-CWC-RVOD and 2C-ICE). The results were in good accordance with 2B-CWC-RVOD in terms of cloud water path and the vertical distribution of CWC but represented underestimates in comparison to 2C-ICE. We performed sensitivity analysis of CWC estimates of TBs and cloud top height. The results suggested that the error in TBs is not large uncertainty, and that cloud top height affects the estimated CWC more sensitively than TBs. The addition of cloud top height information, as determined from CloudSat products as a constraint of optimization, allows further improvement of the vertical distributions of CWC in case studies. Sensitivity analysis indicated that it is effective to utilize cloud top height data from other satellites, such as next-generation geostationary meteorological satellites, within an error of about \u00b1600 m for further development of our method. This study revealed that the proposed method has great potential to provide unprecedented data for cloud water path and CWC that are continuously distributed over land and ocean with adequate accuracy.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1088/1748-9326/AAAA99", "year": 2018, "title": "Changing population dynamics and uneven temperature emergence combine to exacerbate regional exposure to heat extremes under 1.5 C and 2 C of warming", "abstract": "Understanding how continuing increases in global mean temperature will exacerbate societal exposure to extreme weather events is a question of profound importance. However, determining population exposure to the impacts of heat extremes at 1.5\u2009\u00b0C and 2\u2009\u00b0C of global mean warming requires not only (1) a robust understanding of the physical climate system response, but also consideration of (2) projected changes to overall population size, as well as (3) changes to where people will live in the future. This analysis introduces a new framework, adapted from studies of probabilistic event attribution, to disentangle the relative importance of regional climate emergence and changing population dynamics in the exposure to future heat extremes across multiple densely populated regions in Southern Asia and Eastern Africa (SAEA). Our results reveal that, when population is kept at 2015 levels, exposure to heat considered severe in the present decade across SAEA will increase by a factor of 4.1 (2.4-9.6) and 15.8 (5.0-135) under a 1.5\u00b0- and 2.0\u00b0-warmer world, respectively. Furthermore, projected population changes by the end of the century under an SSP1 and SSP2 scenario can further exacerbate these changes by a factor of 1.2 (1.0-1.3) and 1.5 (1.3-1.7), respectively. However, a large fraction of this additional risk increase is not related to absolute increases in population, but instead attributed to changes in which regions exhibit continued population growth into the future. Further, this added impact of population redistribution will be twice as significant after 2.0\u2009\u00b0C of warming, relative to stabilisation at 1.5\u2009\u00b0C, due to the non-linearity of increases in heat exposure. Irrespective of the population scenario considered, continued African population expansion will place more people in locations where emergent changes to future heat extremes are exceptionally severe.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2019JC015898", "year": 2020, "title": "Estimating Southern Ocean Storm Positions With Seismic Observations", "abstract": "Surface winds from Southern Ocean cyclones generate large waves that travel over long distances (>1,000 km). Wave generation regions are often colocated with enhanced air-sea fluxes and upper ocean mixing. Ocean wave spectra contain information about storm wind speed, fetch size, and intensity at their generation site. Two years of seismic observations on the Ross Ice shelf, combined with modern optimization (machine learning) techniques, are used to trace the origins of wave events in the Southern Ocean with an accuracy of \u00b1110 km and \u00b12 hr from a hypothetical point source. The observed spectral energy attenuated within sea ice and in the ice shelf but retains characteristics that can be compared to parametric wave models. Comparison with the Modern-Era Retrospective Analysis for Research and Applications, Version 2, and ERA5 reanalyses suggests that less than 45% of ocean swell events can be associated with individual Southern Ocean storms, while the majority of the observed wave events cannot be matched with Southern Ocean high wind events. Reanalysis cyclones and winds are often displaced by about 350 km or 10 hr in Modern-Era Retrospective Analysis for Research and Applications, Version 2, and ERA5 compared to the most likely positions inferred from the seismic spectra. This high fraction of displaced storms in reanalysis products over the South Pacific can be explained by the limited availability of remote sensing observations, primarily caused by the presence of sea ice. Deviation of wave rays from their great circle path by wave-current interaction plays a minor role.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/SU8030285", "year": 2016, "title": "Paradise Islands? Island States and Environmental Performance", "abstract": "Island states have been shown to outperform continental states on a number of large-scale coordination-related outcomes, such as levels of democracy and institutional quality. The argument developed and tested in this article contends that the same kind of logic may apply to islands environmental performance, too. However, the empirical analysis shows mixed results. Among the 105 environmental outcomes that we analyzed, being an island only has a positive impact on 20 of them. For example, island states tend to outcompete continental states with respect to several indicators related to water quality but not in aspects related to biodiversity, protected areas, or environmental regulations. In addition, the causal factors previously suggested to make islands outperform continental states in terms of coordination have weak explanatory power in predicting islands environmental performance. We conclude the paper by discussing how these interesting findings can be further explored.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.QUASCIREV.2022.107613", "year": 2022, "title": "Late Quaternary hydroclimate of the Levant: The leaf wax record from the Dead Sea", "abstract": "The eastern Mediterranean is projected to experience increases in drought and extreme rainfall in response to rising greenhouse gas emissions. Paleoclimate records from this region are crucial to further constrain the response of the water cycle to a globally warmer climate. Of these, the Dead Sea lacustrine record, collected by the Dead Sea Deep Drilling Project (DSDDP), provides a detailed history of climate change over the past 200,000 years and documents large-magnitude changes in regional water balance. Here, we analyze leaf wax isotopes (Dwax, 13Cwax) on DSDDP 5017-1 and compare results to other proxies analyzed on the same core. The Dwax record closely resembles the speleothem 18O record from nearby Soreq Cave, suggesting that both record a regionally coherent signature of glacial-interglacial cycles and the interplay between winter season rainfall and large-scale expansion and contraction of the Afro-Asian monsoon system. Principal components analysis of the pollen and core lithology shows that the first-order driver of variability in the Dead Sea paleoclimate record is global temperature, which controls effective moisture by modulating atmospheric evaporative demand. Leaf wax, pollen, and core lithology all suggest radical changes in the annual cycle of precipitation during the peak of the Last Interglacial. We hypothesize that the Dead Sea Basin experienced a dual-rainfall regime during this time, with intensified winter storms and a summer monsoon season. While these changes were driven by the Earth's precessional cycle, model simulations suggest a similar expansion of the African monsoon domain into the Arabian Peninsula under elevated CO2 levels. The Last Interglacial climate of the DSB provides a glimpse of what future climate in the southeastern Mediterranean region could look like.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JCLI-D-21-0803.1", "year": 2022, "title": "Comparison between Large-scale Circulation Anomalies Associated with Interannual Variability and Decadal Change of Summer Arctic Sea Ice", "abstract": "Abstract Arctic sea ice in summer shows both interannual and long-term variations, and atmospheric circulation anomalies are known to play an important role. This study compares the summertime large-scale circulation anomalies associated with Arctic sea ice on interannual and decadal time scales. The results indicate that the circulation anomalies associated with decreased sea ice on an interannual time scale are characterized by a barotropic anticyclonic anomaly in the central Arctic, and the thermodynamic process is important for the circulationsea ice coupling. On one hand, the descending adiabatic warming in low levels associated with the central Arctic anticyclonic anomaly leads to decreased sea ice by enhancing the downwelling longwave radiation. On the other hand, the anticyclonic anomaly also induces more moisture in low levels. The enhanced moisture and temperature (coupled with each other) further favor the reduction of sea ice by emitting more downwelling longwave radiation. By contrast, associated with the decadal sea ice decline, there is an anticyclonic anomaly over Greenland and a cyclonic anomaly over northern Siberia, and the wind-driven sea ice drift dominates the sea ice decline. The transpolar circulation anomalies between the anticyclonic and cyclonic anomalies promote transport of the ice away from the coasts of Siberia toward the North Pole, and drive the ice out of the Arctic Ocean to the North Atlantic. These circulation anomalies also induce sea ice decline through thermodynamic process, but it is not as significant as that on an interannual time scale.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1088/1748-9326/AC19DC", "year": 2021, "title": "Temperature emergence at decision-relevant scales", "abstract": "Abstract\r\n \r\n Signal-to-noise (S/N) ratios are a useful method to assess the significance of future climate change relative to past experiences. Most assessments of climate change emergence have focused on S/N ratios of annual mean temperatures. However, averaging the daily experiences of weather across space or time removes the climate variability actually felt by individuals, and thus presents a less informative view of the speed of current climate change. For example, S/N ratios of annual-mean temperatures experienced by the global population after only 1 C of warming are larger than emergent changes in daily temperatures after 3 C of warming, and generally four times more significant when comparing the same warming threshold. Here, I examine the emergence of S/N ratios in temperature at decision-relevant scales, with a focus on daily temperatures where people live. I find that 2 C of global warming will lead to between 30% and >90% of the global population experiencing the emergence of unusual daily temperatures (>1\r\n \r\n ), while it is very unlikely (90% confidence) that more than 60% of the global population will also experience the emergence of unfamiliar daily temperatures (>2\r\n \r\n ).", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.WORLDDEV.2019.104699", "year": 2020, "title": "The impact of climate change on incomes and convergence in Africa", "abstract": "Climate change is projected to detrimentally affect African countries economic development, while income inequalities across economies is among the highest on the planet. However, it is projected that income levels would converge on the continent. Hitherto there is limited evidence on how climate change could affect projected income convergence, accelerating, slowing down, or even reversing this process. Here, we analyze convergence considering climate-change damages, by employing an economic model embedding the three dimensions of risks at the country-level: exposure, vulnerability and hazards. The results show (1) with historical mean climate-induced losses between 10 and 15 percent of GDP per capita growth, the majority of African economies are poorly adapted to their current climatic conditions, (2) Western and Eastern African countries are projected to be the most affected countries on the continent and (3) As a consequence of these heightened impacts on a number of countries, inequalities between countries are projected to widen in the high warming scenario compared to inequalities in the low and without warming scenarios. To mitigate the impacts of economic development and inequalities across countries, we stress (1) the importance of mitigation ambition and Africas leadership in keeping global mean temperature increase below 1.5 C, (2) the need to address the current adaptation deficit as soon as possible, (3) the necessity to integrate quantitatively climate risks in economic and development planning and finally (4) we advocate for the generalization of a special treatment for the most vulnerable countries to access climate-related finance. The analysis raises issues on the ability of African countries to reach their SDGs targets and the potential increasing risk of instability, migration across African countries, of decreased trade and economic cooperation opportunities as a consequence of climate change exacerbating its negative consequences.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1029/2018JD029161", "year": 2018, "title": "TerrainEnhanced Precipitation Processes Above the Melting Layer: Results From OLYMPEX", "abstract": "Enhancement of precipitation processes aloft over complex terrain is documented using reflectivity data from an S-band scanning radar (NPOL) that was deployed on the west coast of Washington State during the Olympic Mountains Experiment (OLYMPEX). From November 2015 through mid-January 2016, NPOL obtained high-resolution data within sectors over the ocean and over the windward slopes of the Olympic Mountains. Contoured Frequency by Altitude Diagrams of radar reflectivity highlight a higher frequency of occurrence of larger reflectivities for all heights between 2 and 8 km over land compared to ocean, with the largest difference in the 4- to 6-km range indicating a robust signature of enhancement aloft over the windward slopes. This enhancement pattern is found to some degree under all environmental conditions considered but is especially pronounced during periods of high vapor transport, high melting level height, southwest low-level winds, and neutral stability. These conditions are generally associated with warm sectors of midlatitude cyclones and atmospheric rivers. Past studies have postulated that a secondary enhancement in reflectivity aloft was an intrinsic part of atmospheric river type systems. However, these results show that further significant enhancement of this signature occurs as deep moist-neutral, high water vapor content flow is lifted when it encounters a mountain range. Reflectivity data from the dual-precipitation radar aboard the Global Precipitation Measurement satellite also documents this reflectivity increase aloft over the Olympic Mountains compared to the adjacent ocean, showing the potential for Global Precipitation Measurement to provide reliable estimates of precipitation structure over remote mountainous regions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/GMD-14-4617-2021", "year": 2021, "title": "Model intercomparison of COSMO 5.0 and IFS 45r1 at kilometer-scale grid spacing", "abstract": "Abstract. The increase in computing power and recent model developments allow for the use of global kilometer-scale weather and climate models for routine forecasts. At these scales, deep convective processes can be partially resolved explicitly by the model dynamics. Next to horizontal resolution, other aspects such as the applied numerical methods, the use of the hydrostatic approximation, and time step size are factors that might influence a model's ability to resolve deep convective processes. In order to improve our understanding of the role of these factors, a model intercomparison between the nonhydrostatic COSMO model and the hydrostatic Integrated Forecast System (IFS) from ECMWF has been conducted. Both models have been run with different spatial and temporal resolutions in order to simulate 2 summer days over Europe with strong convection. The results are analyzed with a focus on vertical wind speed and precipitation. Results show that even at around 3 km horizontal grid spacing the effect of the hydrostatic approximation seems to be negligible. However, time step proves to be an important factor for deep convective processes, with a reduced time step generally allowing for higher updraft velocities and thus more energy in vertical velocity spectra, in particular for shorter wavelengths. A shorter time step is also causing an earlier onset and peak of the diurnal cycle. Furthermore, the amount of horizontal diffusion plays a crucial role for deep convection with more diffusion generally leading to larger convective cells and higher precipitation intensities. The study also shows that for both models the parameterization of deep convection leads to lower updraft and precipitation intensities and biases in the diurnal cycle with a precipitation peak which is too early.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/JCLI-D-20-0722.1", "year": 2021, "title": "Stratospheric and Tropospheric Flux Contributions to the Polar Cap Energy Budgets", "abstract": "Abstract The flux of moist static energy into the polar regions plays a key role in the energy budget and climate of the polar regions. While usually studied from a vertically integrated perspective (Fwall), this analysis examines its vertical structure, using the NASA-MERRA-2 reanalysis to compute climatological and anomalous fluxes of sensible, latent, and potential energy across 70N and 65S for the period 19802016. The vertical structure of the climatological flux is bimodal, with peaks in the middle to lower troposphere and middle to upper stratosphere. The near-zero flux at the tropopause defines the boundary between stratospheric (Fstrat) and tropospheric (Ftrop) contributions to Fwall. Especially at 70N, Fstrat is found to be important to the climatology and variability of Fwall, contributing 20.9 W m2 to Fwall (19% of Fwall) during the winter and explaining 23% of the variance of Fwall. During winter, an anomalous poleward increase in Fstrat preceding a sudden stratospheric warming is followed by an increase in outgoing longwave radiation anomalies, with little influence on the surface energy budget of the Arctic. Conversely, a majority of the energy input by an anomalous poleward increase in Ftrop goes toward warming the Arctic surface. Overall, Ftrop is found to be a better metric than Fwall for evaluating the influence of atmospheric circulations on the Arctic surface climate.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-21-2191-2021", "year": 2021, "title": "Ice injected into the tropopause by deep convection Part 2: Over the Maritime Continent", "abstract": "Abstract. The amount of ice injected into the tropical tropopause layer has a strong radiative impact on climate. A companion paper (Part 1) used the amplitude of the diurnal cycle of ice water content (IWC) as an estimate of ice injection by deep convection, showed that the Maritime Continent (MariCont) region provides the largest injection to the upper troposphere (UT; 146 hPa) and to the tropopause level (TL; 100 hPa). This study focuses on the MariCont region and extends that approach to assess the processes, the areas and the diurnal amount and duration of ice injected over islands and over seas during the austral convective season. The model presented in the companion paper is again used to estimate the amount of ice injected (IWC) by combining ice water content (IWC) measured twice a day by the Microwave Limb Sounder (MLS; Version 4.2) from 2004 to 2017 and precipitation (Prec) measurements from the Tropical Rainfall Measurement Mission (TRMM; Version 007) binned at high temporal resolution (1 h). The horizontal distribution of IWC estimated from Prec (IWCPrec) is presented at 22 horizontal resolution over the MariCont. IWC is also evaluated by using the number of lightning events (Flash) from the TRMM-LIS instrument (Lightning Imaging Sensor, from 2004 to 2015 at 1 h and 0.25 0.25 resolution). IWCPrec and IWC estimated from Flash (IWCFlash) are compared to IWC estimated from the ERA5 reanalyses (IWCERA5) with the vertical resolution degraded to that of MLS observations (IWCERA5). Our study shows that the diurnal cycles of Prec and Flash are consistent with each other in phase over land but different over offshore and coastal areas of the MariCont. The observational IWC range between IWCPrec and IWCFlash, interpreted as the uncertainty of our model in estimating the amount of ice injected, is smaller over land (where IWCPrec and IWCFlash agree to within 22 %) than over ocean (where differences are up to 71 %) in the UT and TL. The impact of the MLS vertical resolution on the estimation of IWC is greater in the TL (difference between IWCERA5 and IWCERA5 of 32 % to 139 %, depending on the study zone) than in the UT (difference of 9 % to 33 %). Considering all the methods, in the UT, estimates of IWC span 4.2 to 10.0 mg m3 over land and 0.4 to 4.4 mg m3 over sea, and in the TL estimates of IWC span 0.5 to 3.9 mg m3 over land and 0.1 to 0.7 mg m3 over sea. Finally, based on IWC from MLS and ERA5, Prec and Flash, this study highlights that (1) at both levels, IWC estimated over land can be more than twice that estimated over sea and (2) small islands with high topography present the largest IWC (e.g., island of Java).", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-10-8821-2010", "year": 2010, "title": "The spatial distribution of mineral dust and its shortwave radiative forcing over North Africa: modeling sensitivities to dust emissions and aerosol size treatments", "abstract": "Abstract. A fully coupled meteorology-chemistry-aerosol model (WRF-Chem) is applied to simulate mineral dust and its shortwave (SW) radiative forcing over North Africa. Two dust emission schemes (GOCART and DUSTRAN) and two aerosol models (MADE/SORGAM and MOSAIC) are adopted in simulations to investigate the modeling sensitivities to dust emissions and aerosol size treatments. The modeled size distribution and spatial variability of mineral dust and its radiative properties are evaluated using measurements (ground-based, aircraft, and satellites) during the AMMA SOP0 campaign from 6 January to 3 February of 2006 (the SOP0 period) over North Africa. Two dust emission schemes generally simulate similar spatial distributions and temporal evolutions of dust emissions. Simulations using the GOCART scheme with different initial (emitted) dust size distributions require ~40% difference in total emitted dust mass to produce similar SW radiative forcing of dust over the Sahel region. The modal approach of MADE/SORGAM retains 25% more fine dust particles (radius<1.25 m) but 8% less coarse dust particles (radius>1.25 m) than the sectional approach of MOSAIC in simulations using the same size-resolved dust emissions. Consequently, MADE/SORGAM simulates 11% higher AOD, up to 13% lower SW dust heating rate, and 15% larger (more negative) SW dust radiative forcing at the surface than MOSAIC over the Sahel region. In the daytime of the SOP0 period, the model simulations show that the mineral dust heats the lower atmosphere with an average rate of 0.8 0.5 K day1 over the Niamey vicinity and 0.5 0.2 K day1 over North Africa and reduces the downwelling SW radiation at the surface by up to 58 W m2 with an average of 22 W m2 over North Africa. This highlights the importance of including dust radiative impact in understanding the regional climate of North Africa. When compared to the available measurements, the WRF-Chem simulations can generally capture the measured features of mineral dust and its radiative properties over North Africa, suggesting that the model is suitable for more extensive simulations of dust impact on regional climate over North Africa.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.2151/JMSJ.2019-058", "year": 2019, "title": "The detection of mesoscale convective systems by the GPM Ku-band spaceborne radar", "abstract": "The Global Precipitation Measurement (GPM) core observatory satellite launched in 2014 features more extended latitudinal coverage (65S-65N) than its predecessor Tropical Rainfall Measuring Mission (TRMM, 35S-35N). The Ku-band radar onboard of the GPM is known to be capable of characterizing the 3D structure of deep convection globally. In this study, GPMs capability for detecting mesoscale convective systems (MCSs) is evaluated. Extreme convective echoes seen by GPM are compared against an MCS database that tracks convective entities over the contiguous US. The tracking is based on geostationary satellite and ground-based Next Generation Radar (NEXRAD) network data obtained during the 2014-2016 warm seasons. Results show that more than 70 % of the GPM-detected Deep-Wide Convective Core (DWC) and Wide Convective Core (WCC) objects are part of NEXRAD identified MCSs, indicating that GPM-classified DWCs and WCCs correlate well with typical MCSs containing large convective features. By applying this method to the rest of the world, a global view of MCS distribution is obtained. This work reveals GPMs potential in MCS detection at the global scale, particularly over remote regions without dense observation network.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.MARCHEM.2015.06.015", "year": 2015, "title": "Quantifying anthropogenic carbon inventory changes in the Pacific sector of the Southern Ocean", "abstract": "The Southern Ocean plays a major role in mediating the uptake, transport, and long-term storage of anthropogenic carbon dioxide (CO2) into the deep ocean. Examining the magnitude and spatial distribution of this oceanic carbon uptake is critical to understanding how the earth's carbon system will react to continued increases in this greenhouse gas. Here, we use the extended multiple linear regression technique to quantify the total and anthropogenic change in dissolved inorganic carbon (DIC) along the S04P and P16S CLIVAR/U.S. Global Ocean Carbon and Repeat Hydrography Program lines south of 67S in the Pacific sector of the Southern Ocean between 1992 and 2011 using discrete bottle measurements from repeat occupations. Along the S04P section, which is located in the seasonal sea ice zone south of the Antarctic Circumpolar Current in the Pacific, the anthropogenic component of the DIC increase from 1992 to 2011 is mostly found in the Antarctic Surface Water (AASW, upper 100m), while the increase in DIC below the mixed layer in the Circumpolar Deep Water can be primarily attributed to either a slowdown in circulation or decreased ventilation of deeper, high CO2 waters. In the AASW we calculate an anthropogenic increase in DIC of 1218molkg1 and an average storage rate of anthropogenic CO2 of 0.100.02molm2yr1 for this region compared to a global average of 0.50.2molm2yr1. In surface waters this anthropogenic CO2 uptake results in an average pH decrease of 0.00220.0004pH unitsyr1, a 0.470.10%yr1 decrease in the saturation state of aragonite (Aragonite) and a 2.00.7myr1 shoaling of the aragonite saturation horizons (calculated for the Aragonite=1.3 contour).", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JCLI-D-19-0674.1", "year": 2020, "title": "The effect of atmospheric transmissivity on model and observational estimates of the sea ice albedo feedback", "abstract": "Abstract The sea ice-albedo feedback (SIAF) is the product of the ice sensitivity (IS), that is, how much the surface albedo in sea ice regions changes as the planet warms, and the radiative sensitivity (RS), that is, how much the top-of-atmosphere radiation changes as the surface albedo changes. We demonstrate that the RS calculated from radiative kernels in climate models is reproduced from calculations using the approximate partial radiative perturbation method that uses the climatological radiative fluxes at the top of the atmosphere and the assumption that the atmosphere is isotropic to shortwave radiation. This method facilitates the comparison of RS from satellite-based estimates of climatological radiative fluxes with RS estimates across a full suite of coupled climate models and, thus, allows model evaluation of a quantity important in characterizing the climate impact of sea ice concentration changes. The satellite-based RS is within the model range of RS that differs by a factor of 2 across climate models in both the Arctic and Southern Ocean. Observed trends in Arctic sea ice are used to estimate IS, which, in conjunction with the satellite-based RS, yields an SIAF of 0.16 0.04 W m2 K1. This Arctic SIAF estimate suggests a modest amplification of future global surface temperature change by approximately 14% relative to a climate system with no SIAF. We calculate the global albedo feedback in climate models using model-specific RS and IS and find a model mean feedback parameter of 0.37 W m2 K1, which is 40% larger than the IPCC AR5 estimate based on using RS calculated from radiative kernel calculations in a single climate model.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.ASR.2021.04.009", "year": 2021, "title": "Satellite-observed lightning hotspots in India and lightning variability over tropical South India", "abstract": "Lightning characteristics in India are examined with satellite-based Lightning Imaging Sensor (LIS) and ground-based Indian Lightning Detection Network (ILDN). LIS observations indicated that synoptic weather systems are major contributors of lightning in Indian hotspots. Western disturbances (mid-tropospheric systems with extratropical origin) were the greatest contributor of lightning in the Himalayas (93%), tropical cyclonic storms and low-pressure systems (oceanic in origin) were key lightning contributors in parts of eastern India (43%), and lower tropospheric troughs were major contributors in other hotspots. For the first time, this study reported the occurrence of significantly high lightning activity before active monsoon spells in the Central India region (6587 E, 1827 N). Consequently, satellite-based lightning observations could be used to predict active monsoon spells. Harmonic analysis was used to study diurnal lightning-flash density. The maximum observed standardized diurnal amplitude of lightning activity was 0.35, and maximum explained diurnal variation was 15%. Also, for the first time, we compared the ILDN data and LIS observations, and found good agreement regarding lightning variability. LIS data showed an increase in annual lightning activity in tropical South-western India (SWI), and the results also suggested that during El Nino and negative Indian Ocean Dipole periods, SWI experiences above-average lightning activity.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-16-1603-2016", "year": 2016, "title": "Aqueous-phase mechanism for secondary organic aerosol formation from isoprene: application to the southeast United States and co-benefit of SO2 emission controls", "abstract": "Abstract. Isoprene emitted by vegetation is an important precursor of secondary organic aerosol (SOA), but the mechanism and yields are uncertain. Aerosol is prevailingly aqueous under the humid conditions typical of isoprene-emitting regions. Here we develop an aqueous-phase mechanism for isoprene SOA formation coupled to a detailed gas-phase isoprene oxidation scheme. The mechanism is based on aerosol reactive uptake coefficients () for water-soluble isoprene oxidation products, including sensitivity to aerosol acidity and nucleophile concentrations. We apply this mechanism to simulation of aircraft (SEAC4RS) and ground-based (SOAS) observations over the southeast US in summer 2013 using the GEOS-Chem chemical transport model. Emissions of nitrogen oxides (NOx NO + NO2) over the southeast US are such that the peroxy radicals produced from isoprene oxidation (ISOPO2) react significantly with both NO (high-NOx pathway) and HO2 (low-NOx pathway), leading to different suites of isoprene SOA precursors. We find a mean SOA mass yield of 3.3 % from isoprene oxidation, consistent with the observed relationship of total fine organic aerosol (OA) and formaldehyde (a product of isoprene oxidation). Isoprene SOA production is mainly contributed by two immediate gas-phase precursors, isoprene epoxydiols (IEPOX, 58 % of isoprene SOA) from the low-NOx pathway and glyoxal (28 %) from both low- and high-NOx pathways. This speciation is consistent with observations of IEPOX SOA from SOAS and SEAC4RS. Observations show a strong relationship between IEPOX SOA and sulfate aerosol that we explain as due to the effect of sulfate on aerosol acidity and volume. Isoprene SOA concentrations increase as NOx emissions decrease (favoring the low-NOx pathway for isoprene oxidation), but decrease more strongly as SO2 emissions decrease (due to the effect of sulfate on aerosol acidity and volume). The US Environmental Protection Agency (EPA) projects 20132025 decreases in anthropogenic emissions of 34 % for NOx (leading to a 7 % increase in isoprene SOA) and 48 % for SO2 (35 % decrease in isoprene SOA). Reducing SO2 emissions decreases sulfate and isoprene SOA by a similar magnitude, representing a factor of 2 co-benefit for PM2.5 from SO2 emission controls.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1093/CVR/CVAA288", "year": 2020, "title": "Regional and global contributions of air pollution to risk of death from COVID-19", "abstract": "The risk of mortality from the coronavirus disease that emerged in 2019 (COVID-19) is increased by comorbidity from cardiovascular and pulmonary diseases. Air pollution also causes excess mortality from these conditions. Analysis of the first severe acute respiratory syndrome coronavirus (SARS-CoV-1) outcomes in 2003, and preliminary investigations of those for SARS-CoV-2 since 2019, provide evidence that the incidence and severity are related to ambient air pollution. We estimated the fraction of COVID-19 mortality that is attributable to the long-term exposure to ambient fine particulate air pollution.We characterized global exposure to fine particulates based on satellite data, and calculated the anthropogenic fraction with an atmospheric chemistry model. The degree to which air pollution influences COVID-19 mortality was derived from epidemiological data in the USA and China. We estimate that particulate air pollution contributed 15% (95% confidence interval 733%) to COVID-19 mortality worldwide, 27% (13 46%) in East Asia, 19% (841%) in Europe, and 17% (639%) in North America. Globally, 5060% of the attributable, anthropogenic fraction is related to fossil fuel use, up to 7080% in Europe, West Asia, and North America.Our results suggest that air pollution is an important cofactor increasing the risk of mortality from COVID-19. This provides extra motivation for combining ambitious policies to reduce air pollution with measures to control the transmission of COVID-19.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/MIN11111158", "year": 2021, "title": "Mg/Ca Ratios in Synthetic Low-Magnesium Calcite: An Experimental", "abstract": "The work presented sought to determine the effects of Mg/Ca ratios in solution have on Mg partitioning (KMg) between precipitated abiotic low-Mg calcite and solution. Experiments were set up so that Mg/Ca in precipitated abiotic calcite would match the Mg/Ca in planktonic foraminifera. This research intended to investigate the effect of Mg/Ca(Fluid) on KMg when the molar value of Mg/Ca(Fluid) was below 0.5, which is below the previously reported Mg/Ca range. The values of pH, salinity, and aqueous Mg/Ca were monitored during calcite precipitation, and Mg/Ca of calcite was determined at the end of experiments. Partition coefficients of Mg were evaluated as a ratio of Mg/Ca in calcite to the averaged ratio of aqueous Mg/Ca for each experiment.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1080/15481603.2022.2026640", "year": 2022, "title": "Spatiotemporal inhomogeneity of total column NO2 in a polluted urban area inferred from TROPOMI and Pandora intercomparisons", "abstract": "The spatiotemporal inhomogeneity of the total column NO2 amounts (TCN) in the Seoul Metropolitan Area (SMA), Korea, was quantitatively assessed through year-round (October 2019May 2021) TROPOMI and ground-based Pandora measurements. The average TCN over the SMA was comparable to that of major Chinese megacities, being consistently high (> 0.8 DU; Dobson Unit) during the daytime (1017 local standard time). The autocorrelation scores of the Pandora-measured TCNs demonstrated high temporal variability attributed to the spatial inhomogeneity of NO2 emissions within the SMA and near-surface advection. Accordingly, the adequate temporal collocation range for Pandora measurements for the intercomparison with the satellite sensors was considered to be 5 min to avoid significant uncertainty from the temporal variability (RMSE < 0.1 DU, R2 > 0.96). TROPOMI showed better agreement with conventionally collocated Pandora measurements (0.73 < R2 < 0.76, 2629% negative bias) than the other two satellite sensors (OMI and OMPS) attributed to its highest spatial resolution. The application of the wind-based collocation revealed that the TROPOMI showed a greater negative bias on the upwind side, which was less affected by anthropogenic emissions from the urban area, than the downwind side, and the increasing distance of the TROPOMI pixel from Pandora was the most critical factor deteriorating the intercomparison scores. The FRESCO-S TROPOMI cloud algorithm update to FRESCO-wide yielded a general increase in TROPOMI TCN, especially in the partially cloudy pixels, leaving only 11% (downwind) and 29% (upwind) negative bias from coincident Pandora measurements. Furthermore, the wind-based collocation method revealed the spatial distribution pattern of NOX (NO + NO2) emissions in the SMA, with significant emission sources in the northeastern and southeastern sides of the ground-based Pandora site in Seoul.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1080/08929882.2017.1318561", "year": 2017, "title": "Economic losses from a fire in a dense-packed US spent fuel pool", "abstract": "In 2013, the staff of the U.S. Nuclear Regulatory Commission estimated the reduction of the off-site economic losses from a fire in a drained U.S. spent fuel pool if fuel that had cooled for more than five years were transferred to dry cask storagean option it called expedited transfer. In this article, it is shown that the savings would be much higher than the NRC estimated. Savings increase to about $2 trillion if: losses beyond 50 miles are included; the land-contamination threshold for long-term population relocation is changed to that used for the Chernobyl and Fukushima accidents and recommended by the U.S. Environmental Protection Agency; and, based on the experience of Japan, decontamination of land areas to levels acceptable for population return is assumed to take at least four years. If expedited transfer were implemented, the off-site economic losses would be reduced by about 98%.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119521", "year": 2022, "title": "Investigating Southeast Asian biomass burning by the WRF-CMAQ two-way coupled model: Emission and direct aerosol radiative effects", "abstract": "Southeast Asia (SEA) is one of the world's major sources of biomass burning (BB). In this study, the recently released Weather Research and Forecasting-Community Multiscale Air Quality (WRF-CMAQ) two-way coupled model was used with the Global Fire Emissions Database Version 4, to investigate the effect of BB emissions on the meteorology and air quality over SEA in March and April 2015. The results show that the model performance was improved by considering BB emissions. When BB pollutants reach the free troposphere, they can be transported by westerly and southwesterly winds to downstream regions. The contributions of BB were up to 48.4 and 35.5 ppbv to surface O3 concentrations and 251.0 and 104.4 g/m3 to surface PM2.5 concentrations in March and April, respectively. The BB emission caused aerosol direct radiative effect (DRE) on the monthly mean clear-sky downward shortwave flux at the ground surface to decrease by 65.4 and 33.6 W/m2 in March and April, respectively. The surface temperature decreased over the land (by a maximum of 0.24 C in March) and increased over the sea, while the temperature at higher levels tended to increase (to a maximum of 0.12 C in March). The BB aerosol DRE caused the planetary boundary layer height (PBLH) to decrease by a maximum of 91.2 m in March. Surface O3 concentrations decreased generally owing to variations in the shortwave flux and temperature. Moreover, the decreased PBLH worsened the diffusion condition within the PBL but also caused larger amounts of BB emissions to penetrate the free atmosphere. This led to a decrease in surface PM2.5 concentrations in southern Indochina and an increase in Myanmar. These findings highlight the key effects of BB emissions on local and downwind meteorology and air quality over SEA and demonstrate the practical applications of the WRF-CMAQ coupled model.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2020GL091913", "year": 2021, "title": "Asian Emissions Explain Much of the Arctic Black Carbon Events", "abstract": "There is ample evidence that Black Carbon (BC) is harmful to the Arctic. BC can darken the otherwise highly reflective surfaces of snow and ice and increase atmospheric and ice surface temperatures. Because of the importance of BC to the Arctic, this work was designed to resolve the most significant source regions of Arctic BC as measured by monitoring stations in the Arctic. Using a bottom up approach, it is shown for the first time that there is one particular BC transport pathway from lower latitudes into the Arctic that registers at all but one of the Arctic surface monitoring stations included in this study. Through this pathway, pollutants are transported from the Indo Gangetic plane over Central Asia into the high Arctic in as little as 7 days. The measurement sites and BC pathways in this study are shown to be well representative of the Arctic as a whole.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2019GB006467", "year": 2020, "title": "A Global Model for Iodine Speciation in the Upper Ocean", "abstract": "An ocean iodine cycling model is presented, which predicts upper ocean iodine speciation. The model comprises a three-layer advective and diffusive ocean circulation model of the upper ocean and an iodine cycling model embedded within this circulation. The two primary reservoirs of iodine are represented, iodide and iodate. Iodate is reduced to iodide in the mixed layer in association with primary production, linked by an iodine to carbon (I:C) ratio. A satisfactory model fit with observations cannot be obtained with a globally constant I:C ratio, and the best fit is obtained when the I:C ratio is dependent on sea surface temperature, increasing at low temperatures. Comparisons with observed iodide distributions show that the best model fit is obtained when oxidation of iodide back to iodate is associated with mixed layer nitrification. Sensitivity tests, where model parameters and processes are perturbed, reveal that primary productivity, mixed layer depth, oxidation, advection, surface freshwater flux, and the I:C ratio all have a role in determining surface iodide concentrations, and the timescale of iodide in the mixed layer is sufficiently long for nonlocal processes to be important. Comparisons of the modeled iodide surface field with parameterizations by other authors show good agreement in regions where observations exist but significant differences in regions without observations. This raises the question of whether the existing parameterizations are capturing the full range of processes involved in determining surface iodide and shows the urgent need for observations in regions where there are currently none.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-21-13729-2021", "year": 2021, "title": "Heterogeneity and chemical reactivity of the remote troposphere defined", "abstract": "Abstract. The NASA Atmospheric Tomography (ATom) mission built a\nphotochemical climatology of air parcels based on in situ measurements with\nthe NASA DC-8 aircraft along objectively planned profiling transects through\nthe middle of the Pacific and Atlantic oceans. In this paper we present and\nanalyze a data set of 10 s (2 km) merged and gap-filled observations of the\nkey reactive species driving the chemical budgets of O3 and CH4\n(O3, CH4, CO, H2O, HCHO, H2O2, CH3OOH,\nC2H6, higher alkanes, alkenes, aromatics, NOx, HNO3,\nHNO4, peroxyacetyl nitrate, other organic nitrates), consisting of\n146 494 distinct air parcels from ATom deployments 1 through 4. Six models\ncalculated the O3 and CH4 photochemical tendencies from this\nmodeling data stream for ATom 1. We find that 80 %90 % of the total\nreactivity lies in the top 50 % of the parcels and 25 %35 % in the top\n10 %, supporting previous model-only studies that tropospheric chemistry\nis driven by a fraction of all the air. In other words, accurate simulation\nof the least reactive 50 % of the troposphere is unimportant for global\nbudgets. Surprisingly, the probability densities of species and reactivities\naveraged on a model scale (100 km) differ only slightly from the 2 km ATom\ndata, indicating that much of the heterogeneity in tropospheric chemistry\ncan be captured with current global chemistry models. Comparing the ATom\nreactivities over the tropical oceans with climatological statistics from\nsix global chemistry models, we find excellent agreement with the loss of\nO3 and CH4 but sharp disagreement with production of O3. The\nmodels sharply underestimate O3 production below 4 km in both Pacific\nand Atlantic basins, and this can be traced to lower NOx levels than\nobserved. Attaching photochemical reactivities to measurements of chemical\nspecies allows for a richer, yet more constrained-to-what-matters, set of\nmetrics for model evaluation.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.IJGGC.2020.103152", "year": 2020, "title": "Comparison and suggestion of indicators of concentrations associated with CO2 in seawater considering biological activity", "abstract": "Carbon dioxide capture and storage is expected to reduce large amount of CO2 emissions from pointwise large sources, such as coal power plants, by 2030 in Japan. For offshore CO2 storage, it is necessary to monitor concentrations associated with CO2 in seawater to ensure safe storage. To do so, it is also necessary to know the baseline concentrations in the target seas. However, such concentrations have large regional and seasonal variations, mainly because of biological activity. In this study, we compared various indicators of CO2 dissolved in seawater, using the seawater off Tomakomai, Japan, observed between 2013 and 2018. Among the indicators, we found very strong correlations between [nDIC + kDO] and T and between [DIC 0.5TA + kDO] and T. These indicators are thought to be effective for investigating the possibility of unexpected leakage of CO2 stored in sub-seabed geological formations. However, data always contain a degree of scattering, even when their correlation is very high. In the case of the seawater off Tomakomai, the data that exceeded a criteria based on the residual standard deviation of some indicators were not necessarily the same as those of the other indicators. Therefore, it is suggested that two or more, different types of indicators should be used, such as pCO2-[DO saturation] and [nDIC + kDO]-T or [DIC 0.5TA + kDO]-T.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.ATMOSENV.2019.116883", "year": 2019, "title": "Simulation of airborne trace metals in fine particulate matter over North America", "abstract": "Trace metal distributions are of relevance to understand sources of fine particulate matter (PM2.5), PM2.5-related health effects, and atmospheric chemistry. However, knowledge of trace metal distributions is lacking due to limited ground-based measurements and model simulations. This study develops a simulation of 12 trace metal concentrations (Si, Ca, Al, Fe, Ti, Mn, K, Mg, As, Cd, Ni and Pb) over continental North America for 2013 using the GEOS-Chem chemical transport model. Evaluation of modeled trace metal concentrations with observations indicates a spatial consistency within a factor of 2. The spatial distribution of trace metal concentrations reflects their primary emission sources. Crustal element (Si, Ca, Al, Fe, Ti, Mn, K) concentrations are enhanced over the central US from anthropogenic fugitive dust and over the southwestern U.S. due to natural mineral dust. Heavy metal (As, Cd, Ni and Pb) concentrations are high over the eastern U.S. from industry. K is abundant in the southeast from biomass burning. High concentrations of Mg are observed along the coast from sea spray. The spatial pattern of PM2.5 mass is most strongly correlated with Pb, Ni, As and K due to their signature emission sources. Challenges remain in accurately simulating observed trace metal concentrations. Halving anthropogenic fugitive dust emissions in the 2011 National Air Toxic Assessment (NATA) inventory and doubling natural dust emissions in the default GEOS-Chem simulation was necessary to reduce biases in crustal element concentrations. A fivefold increase of anthropogenic emissions of As and Pb was necessary in the NATA inventory to reduce the national-scale bias versus observations by more than 80%, potentially reflecting missing sources.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/RS13214252", "year": 2021, "title": "Interannual Variability of the Lena River Plume Propagation in 1993-2020", "abstract": "The Lena River plume significantly affects the thermohaline, optical and chemical properties of the eastern Arctic seas. We use sea surface salinity (SSS), temperature (SST), and altimetry measurements to study features of the Lena plume propagation during 19932020. A comparison of Soil Moisture Active Passive (SMAP) SSS measurements with in situ data obtained using the flow-through system in oceanographic surveys in 20182019 demonstrates good coincidence with correlation ~ 0.96 and RMSD ~ 1 psu. The SMAP data were used to reconstruct the plume evolution in 20152020 and to identify three main types of Lena plume propagation, which are mainly related to the variability of dominant zonal wind direction: northernthe plume moves to the north from the delta up to 78 N; easternthe plume moves eastward along the Siberian coast up to 180 E; mixed between two main types. Brackish plume waters were characterized by increased temperature and sea level, which provides the opportunity for studying the Lena plume dynamics using satellite altimetry and infrared measurements. These data were analyzed to study the interannual variability of plume propagation during the ice-free period of 19932020. The obtained results show that the northern type is observed twice more often than the eastern one, but the eastern type has intensified since 2010.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/RS12233956", "year": 2020, "title": "Modeling Gross Primary Production of Midwestern US Maize and Soybean", "abstract": "Gross primary production (GPP) is a useful metric for determining trends in the terrestrial carbon cycle. To estimate daily GPP, the cloud-adjusted light use efficiency model (LUEc) was developed by adapting a light use efficiency (LUE, ) model to include in situ meteorological data and biophysical parameters. The LUEc uses four scalars to quantify the impacts of temperature, water stress, and phenology on . This study continues the original investigation in using the LUEc, originally limited to three AmeriFlux sites (US-Ne1, US-Ne2, and US-Ne3) by applying gridded meteorological data sets and remotely sensed green leaf area index (gLAI) to estimate daily GPP over a larger spatial extent. This was achieved by including data from four additional AmeriFlux locations in the U.S. Corn Belt for a total of seven locations. Results show an increase in error (RMSE = 3.5 g C m2 d1) over the original study in which in situ data were used (RMSE = 2.6 g C m2 d1). This is attributed to poor representation of gridded weather inputs (vapor pressure and incoming solar radiation) and application of gLAI algorithms to sites in Iowa, Minnesota, and Illinois, calibrated using data from Nebraska sites only, as well as uncertainty due to climatic variation. Despite these constraints, the study showed good correlation between measured and LUEc-modeled GPP (R2 = 0.80 and RMSE of 3.5 g C m2 d1). The decrease in model accuracy is somewhat offset by the ability to function with gridded weather datasets and remotely sensed biophysical data. The level of acceptable error is dependent upon the scope and objectives of the research at hand; nevertheless, the approach holds promise in developing regional daily estimates of GPP.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.IJHYDENE.2021.08.142", "year": 2021, "title": "Evaluating the economic fairways for hydrogen production in Australia", "abstract": "Assessments of hydrogen project viability typically focus on evaluating specific sites for development, or providing generic cost-estimates that are independent of location. In reality, the success of hydrogen projects will be intimately linked to the availability of local energy resources, access to key infrastructure and water supplies, and the distance to export ports and energy markets. In this paper, we present an economic model that incorporates assessments of these regional factors to identify areas of high economic potential for hydrogen production the so-called Economic Fairways for such projects. In doing so, the model provides a tool that can be used to inform investors and policy makers on the available opportunities for hydrogen development and their infrastructure requirements. The model includes analysis of the regional economic potential for both blue and green hydrogen projects. It accounts for hydrogen production from renewable (wind and solar) sources, as well as non-renewable sources (steam-methane reformation and coal gasification) combined with carbon capture and storage. Results from case studies conducted with the tool are presented, illustrating the potential for hydrogen production across Australia.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-18-14493-2018", "year": 2018, "title": "Atmospheric oxidation in the presence of clouds during the Deep Convective Clouds and Chemistry (DC3) study", "abstract": "Abstract. Deep convective clouds are critically important to the distribution of atmospheric constituents throughout the troposphere but are difficult environments to study. The Deep Convective Clouds and Chemistry (DC3) study in 2012 provided the environment, platforms, and instrumentation to test oxidation chemistry around deep convective clouds and their impacts downwind. Measurements on the NASA DC-8 aircraft included those of the radicals hydroxyl (OH) and hydroperoxyl (HO2), OH reactivity, and more than 100 other chemical species and atmospheric properties. OH, HO2, and OH reactivity were compared to photochemical models, some with and some without simplified heterogeneous chemistry, to test the understanding of atmospheric oxidation as encoded in the model. In general, the agreement between the observed and modeled OH, HO2, and OH reactivity was within the combined uncertainties for the model without heterogeneous chemistry and the model including heterogeneous chemistry with small OH and HO2 uptake consistent with laboratory studies. This agreement is generally independent of the altitude, ozone photolysis rate, nitric oxide and ozone abundances, modeled OH reactivity, and aerosol and ice surface area. For a sunrise to midday flight downwind of a nighttime mesoscale convective system, the observed ozone increase is consistent with the calculated ozone production rate. Even with some observed-to-modeled discrepancies, these results provide evidence that a current measurement-constrained photochemical model can simulate observed atmospheric oxidation processes to within combined uncertainties, even around convective clouds. For this DC3 study, reduction in the combined uncertainties would be needed to confidently unmask errors or omissions in the model chemical mechanism.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.RESCONREC.2021.105865", "year": 2021, "title": "Underreporting and open burning\u2013the two largest challenges for sustainable waste management in India", "abstract": "The total waste generation in India reported for 2015 is highly uncertain (51300 Tgy1), primarily because observational data from rural regions within India is lacking. This makes it difficult to constrain rural waste generation rates. Official government data (51 Tg) denies the existence of rural waste generation in India. The rural data gap makes it difficult to construct accurate open waste burning emission inventories and plan waste management infrastructure. Our study presents activity data from understudied rural regions across India and establishes a relationship between waste generation and household income for both urban and rural India. We use this relationship to create a 0.1 x 0.1 gridded waste generation and waste treatment dataset and construct an open waste burning emission inventory for India (OWBEII) for the year 2020, after segregating both the rural and urban population into 5 income group with the help of socioeconomic data from the national health surveys. We find that out of 192 (102231) Tgy1 waste generated in 2020, 74 (3092) Tgy1 was burned in the open. Open waste burning is a widely established practice of waste disposal in developing nations and emits particulate matter (2851401 Ggy1 PM2.5 and 3221486 Ggy1 PM10), a suite of carcinogens (1982 Ggy1 benzene) and very reactive VOCs, which act as precursors to tropospheric ozone and secondary aerosol formation. The anthropogenic emissions of formaldehyde (a Group 1 carcinogen) from this source are 5.7 times larger than India's currently recognized total anthropogenic budget of formaldehyde in the EDGARv4.3.2 emission inventory.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11356-021-17139-5", "year": 2021, "title": "Variation patterns and driving factors of regional atmospheric CO2 anomalies in China", "abstract": "Atmospheric CO2 anomaly (XCO2) is essential in evaluating regional carbon balance. However, it is difficult to understand XCO2 variation characteristics due to regional differences. This paper explored the inter-annual and inter-monthly variation patterns of XCO2 in different regions of China based on satellite observations. The relation model between regional XCO2 and anthropogenic emissions, gross primary productivity (GPP), wind speed, upwind regions emission, and upwind regions CO2 concentration was established. Results show that the annual average XCO2 in the northwest and southeast regions is stable at around 0 and 12 ppm, respectively. Some municipalities directly under the central government and the southern coastal areas showed relatively intense inter-annual fluctuations. Four inter-monthly XCO2 variation patterns were observed: the northern region has a stable change, the northeast region has the lowest in summer, the southwest region has the highest in summer, and the central region has no obvious change rule. Furthermore, XCO2 in most areas can be explained by the emissionabsorptiontransportation model. Significant positive XCO2 in the southern coastal region in summer may be related to the stable GPP seasonal variation and increased power generation. In the southwestern plateau region, it may be related to the low wind speed and increased soil emission with rising temperature. The stability of the plateau carbon sink and inter-regional cooperation cannot be ignored for improving regional atmospheric environments.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-20-13091-2020", "year": 2020, "title": "Long-term observational constraints of organic aerosol dependence on inorganic species in the southeast US", "abstract": "Abstract. Organic aerosol (OA), with a large biogenic fraction in the summertime southeast US, adversely impacts air quality and human health. Stringent air\nquality controls have recently reduced anthropogenic pollutants including sulfate, whose impact on OA remains unclear. Three filter measurement\nnetworks provide long-term constraints on the sensitivity of OA to changes in inorganic species, including sulfate and ammonia. The 20002013\nsummertime OA decreases by 1.7 % yr11.9 % yr1 with little month-to-month variability, while sulfate\ndeclines rapidly with significant monthly difference in the early 2000s. In contrast, modeled OA from a chemical-transport model (GEOS-Chem) decreases\nby 4.9 % yr1 with much larger monthly variability, largely due to the predominant role of acid-catalyzed reactive uptake of\nepoxydiols (IEPOX) onto sulfate. The overestimated modeled OA dependence on sulfate can be improved by implementing a coating effect and assuming\nconstant aerosol acidity, suggesting the needs to revisit IEPOX reactive uptake in current models. Our work highlights the importance of secondary\nOA formation pathways that are weakly dependent on inorganic aerosol in a region that is heavily influenced by both biogenic and anthropogenic\nemissions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/NCOMMS15611", "year": 2017, "title": "River plastic emissions to the world's oceans", "abstract": "Plastics in the marine environment have become a major concern because of their persistence at sea, and adverse consequences to marine life and potentially human health. Implementing mitigation strategies requires an understanding and quantification of marine plastic sources, taking spatial and temporal variability into account. Here we present a global model of plastic inputs from rivers into oceans based on waste management, population density and hydrological information. Our model is calibrated against measurements available in the literature. We estimate that between 1.15 and 2.41 million tonnes of plastic waste currently enters the ocean every year from rivers, with over 74% of emissions occurring between May and October. The top 20 polluting rivers, mostly located in Asia, account for 67% of the global total. The findings of this study provide baseline data for ocean plastic mass balance exercises, and assist in prioritizing future plastic debris monitoring and mitigation strategies.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.5194/PIAHS-376-83-2018", "year": 2018, "title": "Socio-Hydrological Approach to the Evaluation of Global Fertilizer Substitution by Sustainable Struvite Precipitants from Wastewater", "abstract": "Abstract. Despite Africa controlling the vast majority of the global phosphate it also faces the greatest food shortages partially due to a lack of access to the fertilizer market. A more accessible source of phosphorus comes from wastewater flows, which is currently lost through the discharge to open surface waters. Analysing the potential phosphorus production of urban and livestock wastewater in meeting partial agricultural demand for phosphorus can improve food security, reduce consumption of unrenewable phosphorus, reduce pollution, and aid the transitioning to a circular economy. In this study, a global overview is provided where a selection of P-production and P-consumption sites have been determined using global spatial data. Distances, investment costs and associated carbon footprints are then considered in modelling a simple, alternative trade network of struvite phosphorus flows. The network reveals potential for increasing the phosphorus security through phosphorus recycling in particularly the South Africa, Lake Victoria and Nigeria regions. Given Africa's rapid urbanization, phosphorus recovery from wastewater will prove an important step in creating sustainable communities, protecting the environment while improving food security, and so contributing to the United Nations 2030 Agenda for Sustainable Development.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1029/2019JD030528", "year": 2020, "title": "Constraining Fossil Fuel CO2 Emissions From Urban Area Using OCO-2 Observations of Total Column CO2", "abstract": "Satellite observations of the total column dry-air CO2 (XCO2) are expected to support the quantification and monitoring of fossil fuel CO2 (ffCO2) emissions from urban areas. We evaluate the utility of the Orbiting Carbon Observatory 2 (OCO-2) XCO2 retrievals to optimize whole-city emissions, using a Bayesian inversion system and high-resolution transport modeling. The uncertainties of constrained emissions related to transport model, satellite measurements, and local biospheric fluxes are quantified. For the first two uncertainty sources, we examine cities of different landscapes: \"plume city\" located in relatively flat terrain, represented by Riyadh and Cairo; and \"basin city\" located in basin terrain, represented by Los Angeles (LA). The retrieved scaling factors of emissions and their uncertainties show prominent variabilities from track to track, due to the varying meteorological conditions and relative locations of the tracks transecting plumes. To explore the performance of multiple tracks in retrieving emissions, pseudo data experiments are carried out. The estimated least numbers of tracks required to constrain the total emissions for Riyadh (<10% uncertainty), Cairo (<10%), and LA (<5%) are 8, 5, and 7, respectively. Additionally, to evaluate the impact of biospheric fluxes on derivation of the ffXCO2 enhancements, we conduct simulations for Pearl River Delta metropolitan area. Significant fractions of local XCO2 enhancements associated with local biospheric XCO2 variations are shown, which potentially lead to biased estimates of ffCO2 emissions. We demonstrate that satellite measurements can be used to improve urban ffCO2 emissions with a sufficient amount of measurements and appropriate representations of the uncertainty components.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1371/JOURNAL.PONE.0227764", "year": 2020, "title": "Spatial variation in fertilizer prices in Sub-Saharan Africa", "abstract": "Low crop yields in Sub-Saharan Africa are associated with low fertilizer use. To better understand patterns of, and opportunities for, fertilizer use, location specific fertilizer price data may be relevant. We compiled local market price data for urea fertilizer, a source of inorganic nitrogen, in 1729 locations in eighteen countries in two regions (West and East Africa) from 20102018 to understand patterns in the spatial variation in fertilizer prices. The average national price was lowest in Ghana (0.80 USD kg-1), Kenya (0.97 USD kg-1), and Nigeria (0.99 USD kg-1). Urea was most expensive in three landlocked countries (Burundi: 1.51, Uganda: 1.49, and Burkina Faso: 1.49 USD kg-1). Our study uncovers considerable spatial variation in fertilizer prices within African countries. We show that in many countries this variation can be predicted for unsampled locations by fitting models of prices as a function of longitude, latitude, and additional predictor variables that capture aspects of market access, demand and environmental conditions. Predicted within-country urea price variation (as a fraction of the median price) was particularly high in Kenya (0.771.12), Nigeria (0.831.34), Senegal (0.731.40), Tanzania (0.901.29) and Uganda (0.931.30), but much lower in Burkina Faso (0.961.04), Burundi (0.951.05), and Togo (0.941.05). The correlation coefficient of the country level models was between 0.17 to 0.83 (mean 0.52) and the RMSE varies from 0.005 to 0.188 (mean 0.095). In 10 countries, predictions were at least 25% better than a null-model that assumes no spatial variation. Our work indicates new opportunities for incorporating spatial variation in prices into efforts to understand the profitability of agricultural technologies across rural areas in Sub-Saharan Africa.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1126/SCIENCE.ADE2315", "year": 2022, "title": "Tackling unlit and inefficient gas flaring", "abstract": "Emissions from flaring threaten the global climate and the health of local communities\r\n , \r\n \r\n Because of the outsized warming potential of methane, it is essential to limit this superpollutant to mitigate the worsening global climate emergency. More than 120 nations have signed the Global Methane Pledge to cut emissions by 30% by 2030 (\r\n \r\n 1\r\n \r\n ). Some 80 oil and gas (O&G) companies have joined the Oil and Gas Methane Partnership, which aims to establish a reporting framework for methane emissions (\r\n \r\n 2\r\n \r\n ), such as those from flaringthe practice of burning off unwanted gas. The World Bank has enlisted public and private stakeholders to commit to zero routine flaring by 2030 (\r\n \r\n 3\r\n \r\n ). On page 1566 of this issue, Plant\r\n et al.\r\n (\r\n \r\n 4\r\n \r\n ) report an average methane destruction removal efficiency of 87 to 94% by flaring in US-based O&G facilities. This number is much lower than what was previously assumed, and the authors attribute this to inefficient and unlit flares.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/AMT-15-459-2022", "year": 2022, "title": "A systematic re-evaluation of methods for quantification of bulk particle-phase organic nitrates using real-time aerosol mass spectrometry", "abstract": "Abstract. Organic nitrate (RONO2) formation in the atmosphere represents a sink of NOx (NOx = NO + NO2) and termination of the NOx/HOx (HOx = HO2 + OH) ozone formation and radical propagation cycles, can act as a NOx reservoir transporting reactive nitrogen, and contributes to secondary organic aerosol formation. While some fraction of RONO2 is thought to reside in the particle phase, particle-phase organic nitrates (pRONO2) are infrequently measured and thus poorly understood. There is an increasing prevalence of aerosol mass spectrometer (AMS) instruments, which have shown promise for determining the quantitative total organic nitrate functional group contribution to aerosols. A simple approach that relies on the relative intensities of NO+ and NO2+ ions in the AMS spectrum, the calibrated NOx+ ratio for NH4NO3, and the inferred ratio for pRONO2 has been proposed as a way to apportion the total nitrate signal to NH4NO3 and pRONO2. This method is increasingly being applied to field and laboratory data. However, the methods applied have been largely inconsistent and poorly characterized, and, therefore, a detailed evaluation is timely. Here, we compile an extensive survey of NOx+ ratios measured for various pRONO2 compounds and mixtures from multiple AMS instruments, groups, and laboratory and field measurements. All data and analysis presented here are for use with the standard AMS vaporizer. We show that, in the absence of pRONO2 standards, the pRONO2 NOx+ ratio can be estimated using a ratio referenced to the calibrated NH4NO3 ratio, a so-called Ratio-of-Ratios method (RoR = 2.75 0.41). We systematically explore the basis for quantifying pRONO2 (and NH4NO3) with the RoR method using ground and aircraft field measurements conducted over a large range of conditions. The method is compared to another AMS method (positive matrix factorization, PMF) and other pRONO2 and related (e.g., total gas + particle RONO2) measurements, generally showing good agreement/correlation. A broad survey of ground and aircraft AMS measurements shows a pervasive trend of higher fractional contribution of pRONO2 to total nitrate with lower total nitrate concentrations, which generally corresponds to shifts from urban-influenced to rural/remote regions. Compared to ground campaigns, observations from all aircraft campaigns showed substantially lower pRONO2 contributions at midranges of total nitrate (0.010.1 up to 25 g m3), suggesting that the balance of effects controlling NH4NO3 and pRONO2 formation and lifetimes such as higher humidity, lower temperatures, greater dilution, different sources, higher particle acidity, and pRONO2 hydrolysis (possibly accelerated by particle acidity) favors lower pRONO2 contributions for those environments and altitudes sampled.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/2016JD025568", "year": 2016, "title": "Using satellite-based measurements to explore spatiotemporal scales and", "abstract": "New particle formation (NPF) can potentially alter regional climate by increasing aerosol particle (hereafter particle) number concentrations and ultimately cloud condensation nuclei. The large scales on which NPF is manifest indicate potential to use satellite-based (inherently spatially averaged) measurements of atmospheric conditions to diagnose the occurrence of NPF and NPF characteristics. We demonstrate the potential for using satellite-based measurements of insolation (UV), trace gas concentrations (sulfur dioxide (SO2), nitrogen dioxide (NO2), ammonia (NH3), formaldehyde (HCHO), and ozone (O3)), aerosol optical properties (aerosol optical depth (AOD) and \u00c5ngstr\u00f6m exponent (AE)), and a proxy of biogenic volatile organic compound emissions (leaf area index (LAI) and temperature (T)) as predictors for NPF characteristics: formation rates, growth rates, survival probabilities, and ultrafine particle (UFP) concentrations at five locations across North America. NPF at all sites is most frequent in spring, exhibits a one-day autocorrelation, and is associated with low condensational sink (AOD \u00d7 AE) and HCHO concentrations, and high UV. However, there are important site-to-site variations in NPF frequency and characteristics, and in which of the predictor variables (particularly gas concentrations) significantly contribute to the explanatory power of regression models built to predict those characteristics. This finding may provide a partial explanation for the reported spatial variability in skill of simple generalized nucleation schemes in reproducing observed NPF. In contrast to more simple proxies developed in prior studies (e.g., based on AOD, AE, SO2, and UV), use of additional predictors (NO2, NH3, HCHO, LAI, T, and O3) increases the explained temporal variance of UFP concentrations at all sites.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-12-2067-2019", "year": 2019, "title": "OMI total bromine monoxide (OMBRO) data product: Algorithm, retrieval and measurement comparisons", "abstract": "Abstract. This paper presents the retrieval algorithm for the operational Ozone Monitoring Instrument (OMI) total bromine monoxide (BrO) data product (OMBRO) developed at the Smithsonian Astrophysical Observatory (SAO) and shows comparisons with correlative measurements and retrieval results. The algorithm is based on direct nonlinear least squares fitting of radiances from the spectral range 319.0347.5 nm. Radiances are modeled from the solar irradiance, attenuated by contributions from BrO and interfering gases, and including rotational Raman scattering, additive and multiplicative closure polynomials, correction for Nyquist undersampling and the average fitting residual spectrum. The retrieval uses albedo- and wavelength-dependent air mass factors (AMFs), which have been pre-computed using a single mostly stratospheric BrO profile. The BrO cross sections are multiplied by the wavelength-dependent AMFs before fitting so that the vertical column densities (VCDs) are retrieved directly. The fitting uncertainties of BrO VCDs typically vary between 4 and 71012 molecules cm2 (10 %20 % of the measured BrO VCDs). Additional fitting uncertainties can be caused by the interferences from O2-O2 and H2CO and their correlation with BrO. AMF uncertainties are estimated to be around 10 % when the single stratospheric-only BrO profile is used. However, under conditions of high tropospheric concentrations, AMF errors due to this assumption of profile can be as high as 50 %. The retrievals agree well with GOME-2 observations at simultaneous nadir overpasses and with ground-based zenith-sky measurements at Harestua, Norway, with mean biases less than -0.221.131013 and 0.120.761013 molecules cm2, respectively. Global distribution and seasonal variation of OMI BrO are generally consistent with previous satellite observations. Finally, we confirm the capacity of OMBRO retrievals to observe enhancements of BrO over the US Great Salt Lake despite the current retrieval setup considering a stratospheric profile in the AMF calculations. OMBRO retrievals also show significant BrO enhancements from the eruption of the Eyjafjallajokull volcano, although the BrO retrievals are affected under high SO2 loading conditions by the sub-optimum choice of SO2 cross sections.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1088/1748-9326/ABC9E1", "year": 2020, "title": "Country-scale trends in air pollution and fossil fuel CO2 emissions during 2001\u20132018: confronting the roles of national policies and economic growth", "abstract": "Abstract\r\n \r\n Fossil fuel (FF) burning, the main energy source of the modern worlds economy, remains the major source of anthropogenic carbon dioxide (CO\r\n 2\r\n ) and pollutants in the atmosphere. Based on 18 years (20012018) of aerosol optical depth (AOD) data from Moderate Resolution Imaging Spectroradiometer satellite, FFCO\r\n 2\r\n emissions from the Open-Data Inventory for Anthropogenic Carbon dioxide, and gross domestic product (GDP) data from the World Bank, we found that air quality, FF consumption, and economy are strongly bonded at the continental scale but decoupled at the national level under favorable policies. The comparison of AOD vs PM\r\n 2.5\r\n and NO\r\n 2\r\n over urbanized areas shows that the pollutants leading to the AOD load can vary significantly by country. A strong connection between GDP and FFCO\r\n 2\r\n emissions indicates that economic growth deeply replies on FF consumption in most countries. Meanwhile, air pollution is more associated with the growing trend than the level of development of a country. With more mature technologies and renewable energy, economies can keep growing without compromising their environment and population health.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/2016JD025482", "year": 2016, "title": "Substantial contribution of northern high-latitude sources to mineral", "abstract": "In the Arctic, impurities in the atmosphere and cryosphere can strongly affect the atmospheric radiation and surface energy balance. While black carbon has hence received much attention, mineral dust has been in the background. Mineral dust is not only transported into the Arctic from remote regions but also, possibly increasingly, generated in the region itself. Here we study mineral dust in the Arctic based on global transport model simulations. For this, we have developed a dust mobilization scheme in combination with the Lagrangian particle dispersion model FLEXPART. A model evaluation, based on measurements of surface concentrations and annual deposition at a number of stations and aircraft vertical profiles, shows the suitability of this model to study global dust transport. Simulations indicate that about 3% of global dust emission originates from high-latitude dust sources in the Arctic. Due to limited convection and enhanced efficiency of removal, dust emitted in these source regions is mostly deposited closer to the source than dust from for instance Asia or Africa. This leads to dominant contributions of local dust sources to total surface dust concentrations ( 85%) and dust deposition ( 90%) in the Arctic region. Dust deposition from local sources peaks in autumn, while dust deposition from remote sources occurs mainly in spring in the Arctic. With increasing altitude, remote sources become more important for dust concentrations as well as deposition. Therefore, total atmospheric dust loads in the Arctic are strongly influenced by Asian ( 38%) and African ( 32%) dust, whereas local dust contributes only 27%. Dust loads are thus largest in spring when remote dust is efficiently transported into the Arctic. Overall, our study shows that contributions of local dust sources are more important in the Arctic than previously thought, particularly with respect to surface concentrations and dust deposition.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-11-12437-2011", "year": 2011, "title": "Emission controls versus meteorological conditions in determining aerosol concentrations in Beijing during the 2008 Olympic Games", "abstract": "Abstract. A series of emission control measures were undertaken in Beijing and the adjacent provinces in China during the 2008 Beijing Olympic Games on 824 August 2008. This provides a unique opportunity for investigating the effectiveness of emission controls on air pollution in Beijing. We conducted a series of numerical experiments over East Asia for the period of July to September 2008 using a coupled meteorology-chemistry model (WRF-Chem). Model can generally reproduce the observed variation of aerosol concentrations. Consistent with observations, modeled concentrations of aerosol species (sulfate, nitrate, ammonium, black carbon, organic carbon, total particulate matter) in Beijing were decreased by 3050% during the Olympic period compared to the other periods in July and August in 2008 and the same period in 2007. Model results indicate that emission controls were effective in reducing the aerosol concentrations by comparing simulations with and without emission controls. In addition to emission controls, our analysis suggests that meteorological conditions (e.g. wind direction and precipitation) were also important in producing the low aerosol concentrations appearing during the Olympic period. Transport from the regions surrounding Beijing determined the daily variation of aerosol concentrations in Beijing. Based on the budget analysis, we suggest that to improve the air quality over Beijing, emission control strategy should focus on the regional scale instead of the local scale.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2022JD036618", "year": 2022, "title": "Impacts of the Desiccation of the Aral Sea on the Central Asian Dust LifeCycle", "abstract": "The formation of the Aralkum (Aral Desert), following the severe desiccation of the former Aral Sea since the 1960s, has created what may be regarded as one of the world's most significant anthropogenic dust sources. In this paper, focusing on dust emission and transport patterns from the Aralkum, the dust life-cycle has been simulated over Central Asia using the aerosol transport model COSMO-MUSCAT (COnsortium for Small-scale MOdelling-MUltiScale Chemistry Aerosol Transport Model), making use of the Global Surface Water data set to take into account the sensitivity to changes in surface water coverage over the region between the 1980s (the \"past\") and the 2010s (the \"present\"). Over a case study 1-year period, the simulated dust emissions from the Aralkum region increased from 14.3 to 27.1 Tg year-1 between the past and present, an increase driven solely by the changes in the surface water environment. Of these simulated modern emissions, 14.5 Tg are driven by westerly winds, indicating that regions downwind to the east may be worst affected by Aralkum dust. However a high degree of interannual variability in the prevailing surface wind patterns ensures that these transport patterns of Aralkum dust do not occur every year. Frequent cloud cover poses substantial challenges for observations of Central Asian dust: in the Aralkum, over two-thirds of the yearly emissions are emitted under overcast skies, dust which may be impossible to observe using traditional satellite or ground-based passive remote sensing techniques. Furthermore, it is apparent that the pattern of dust transport from the Aralkum under clear-sky conditions is not representative of the pattern under all-sky conditions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-12-129-2019", "year": 2019, "title": "Evaluation of version 3.0B of the BEHR OMI NO2 product", "abstract": "Abstract. Version 3.0B of the Berkeley High Resolution (BEHR) Ozone Monitoring Instrument (OMI) NO2 product is designed to accurately retrieve daily variation in the high-spatial-resolution mapping of tropospheric column NO2 over continental North America between 25 and 50 N. To assess the product, we compare against in situ aircraft profiles and Pandora vertical column densities (VCDs). We also compare the WRF-Chem simulation used to generate the a priori NO2 profiles against observations. We find that using daily NO2 profiles improves the VCDs retrieved in urban areas relative to low-resolution or monthly a priori NO2 profiles by amounts that are large compared to current uncertainties in NOx emissions and chemistry (of the order of 10 % to 30 %). Based on this analysis, we offer suggestions to consider when designing retrieval algorithms and validation procedures for upcoming geostationary satellites.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-15-7685-2015", "year": 2015, "title": "Estimates of black carbon emissions in the western United States using the GEOS-Chem adjoint model", "abstract": "Abstract. We estimate black carbon (BC) emissions in the western United States for JulySeptember 2006 by inverting surface BC concentrations from the Interagency Monitoring of Protected Visual Environments (IMPROVE) network using a global chemical transport model (GEOS-Chem) and its adjoint. Our best estimate of the BC emissions is 49.9 Gg at 2 2.5 (a factor of 2.1 increase) and 47.3 Gg at 0.5 0.667 (1.9 times increase). Model results now capture the observed major fire episodes with substantial bias reductions (~ 35 % at 2 2.5 and ~ 15 % at 0.5 0.667). The emissions are ~ 2050 % larger than those from our earlier analytical inversions (Mao et al., 2014). The discrepancy is especially drastic in the partitioning of anthropogenic versus biomass burning emissions. The August biomass burning BC emissions are 4.66.5 Gg and anthropogenic BC emissions 8.612.8 Gg, varying with the model resolution, error specifications, and subsets of observations used. On average both anthropogenic and biomass burning emissions in the adjoint inversions increase 2-fold relative to the respective {a priori} emissions, in distinct contrast to the halving of the anthropogenic and tripling of the biomass burning emissions in the analytical inversions. We attribute these discrepancies to the inability of the adjoint inversion system, with limited spatiotemporal coverage of the IMPROVE observations, to effectively distinguish collocated anthropogenic and biomass burning emissions on model grid scales. This calls for concurrent measurements of other tracers of biomass burning and fossil fuel combustion (e.g., carbon monoxide and carbon isotopes). We find that the adjoint inversion system as is has sufficient information content to constrain the total emissions of BC on the model grid scales.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2020JD033651", "year": 2021, "title": "Evaluation of Aerosol Properties Observed by DSCOVR/EPIC Instrument From the Earth\u2010Sun Lagrange 1 Orbit", "abstract": "Frequent observations of aerosols from space are essential for studying aerosol effects on climate and air quality applications. We present results of aerosol properties derived from observations made by the Earth Polychromatic Imaging Camera (EPIC) sensor onboard the Deep Space Climate Observatory satellite. EPIC's near-hourly measured radiances at 340 and 388 nm from sun rise to sunset have been used as input to the EPIC near-UV aerosol algorithm (EPICAERUV) for retrieving aerosol extinction optical depth (AOD), single scattering albedo (SSA), above-cloud aerosol optical depth (ACAOD), and ultraviolet Aerosol Index. Comparisons of AERONET and EPIC daily mean AOD values at eight selected representative sites yield correlation coefficients in the range from 0.68 to 0.89 and root mean square errors from 0.10 to 0.31. A similar comparison of EPIC-retrieved SSA against the AERONET inverted SSA product revealed nearly 51% (76%) of matchups in agreement within \u00b10.03 (\u00b10.05). Furthermore, the retrievals of ACAOD are also found to compare reasonably well, with 50%-70% of matchups falling within expected uncertainty against the direct airborne measurements acquired during the ObseRvations of Aerosols above CLouds and their intEractionS campaign. Using the EPICAERUV aerosol product, we analyzed the spatial and temporal patterns of specific smoke events caused by wildfires over North America over the last four years.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.147899", "year": 2021, "title": "Satellite-detected ammonia changes in the United States: Natural or anthropogenic impacts", "abstract": "Ammonia (NH3) is the most abundant alkaline component and can react with atmospheric acidic species to form aerosols that can lead to numerous environmental and health issues. Increasing atmospheric NH3 over agricultural regions in the US has been documented. However, spatiotemporal changes of NH3 concentrations over the entire US are still not thoroughly understood, and the factors that drive these changes remain unknown. Herein, we applied the Atmospheric Infrared Sounder (AIRS) monthly NH3 dataset to explore spatiotemporal changes in atmospheric NH3 and the empirical relationships with synthetic N fertilizer application, livestock manure production, and climate factors across the entire US at both regional and pixel levels from 2002 to 2016. We found that, in addition to the US Midwest, the Mid-South and Western regions also experienced striking increases in NH3 concentrations. NH3 released from livestock manure during warmer winters contributed to increased annual NH3 concentrations in the Western US. The influence of temperature on temporal evolution of NH3 concentrations was associated with synthetic N fertilizer use in the Northern Great Plains. With a strong positive impact of temperature on NH3 concentrations in the US Midwest, this region could possibly become an atmospheric NH3 hotspot in the context of future warming. Our study provides an essential scientific basis for US policy makers in developing mitigation strategies for agricultural NH3 emissions under future climate change scenarios.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2020GL090542", "year": 2021, "title": "Weakened aerosol\u2010PBL interaction during COVID\u201019 lockdown in northern China", "abstract": "Anthropogenic emissions were greatly constrained during COVID 19 lockdown in China. Nevertheless, observations still showed high loadings of fine particles (PM2.5) over northern China with secondary aerosols increasing by 15 \u03bcg/m3 yet a \u223c10% drop in light absorbing black carbon (BC). Such a chemical transition in aerosol composition tended to make the atmosphere more scattering, indicated by satellite retrieved aerosol absorption optical depth falling by 60%. Comparison between weather forecast and radiosonde observations illustrated that, without upper level heating induced by BC, the stabilized stratification diminished, which was conducive for planetary boundary layer (PBL) mixing and thus near surface pollution dispersion. Furthermore, coupled dynamic chemistry simulations estimated that emission reduction during the lockdown weakened aerosol PBL interaction and thus a reduction of 25 \u03bcg/m3 (\u223c50%) in PM2.5 enhancement. Based on the unique natural experiment, this work observationally confirmed and numerically quantified the importance of BC induced meteorological feedback, further highlighting the priority of BC control in haze mitigation.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2020JD033015", "year": 2020, "title": "Measurements of Tropospheric Bromine Monoxide Over Four Halogen Activation Seasons in the Canadian High Arctic", "abstract": "Bromine explosions and corresponding ozone depletion events are common in the Arctic spring. The snowpack on sea ice and sea salt aerosols (SSA) are both thought to release bromine, but the relative contribution of each source is not yet known. Furthermore, the role of atmospheric conditions is not fully understood. Long-term measurements of bromine monoxide (BrO) provide useful insight into the underlying processes of bromine activation. Here we present a 4-year data set (2016-2019) of springtime BrO partial columns retrieved from Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) measurements in Eureka, Canada (80.1\u00b0N, 86.4\u00b0W, 610 m asl). Due to the elevation of the measurement site, the instrument often measures BrO in the free troposphere, except during strong wind episodes and storms that generate a deep boundary layer. Enhanced vertical mixing due to strong winds leads to increasing BrO values and reduced ozone depletion. We find that BrO enhancements show two modes differentiated by local wind direction and air mass history. Longer time spent by the airmass in first-year sea ice areas corresponds to increased BrO for one of these modes only. Furthermore, we argue that snow on multiyear ice might also contribute to bromine release. High aerosol optical depth is required to maintain lofted BrO, and we show that the presence of coarse-mode aerosols (>0.5 \u03bcm, likely SSA) is a necessary and sufficient condition for observing BrO at our elevated measurement site in Eureka. This work highlights the importance of considering variable local conditions when characterizing bromine activation.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1186/S12940-018-0430-X", "year": 2018, "title": "Associations of greenness, greyness and air pollution exposure with children's health: a cross-sectional study in Southern Italy", "abstract": "Due to the complex interplay among different urban-related exposures, a comprehensive approach is advisable to estimate the health effects. We simultaneously assessed the effect of green, grey and air pollution exposure on respiratory/allergic conditions and general symptoms in schoolchildren.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/ESSD-13-4175-2021", "year": 2021, "title": "Land-use harmonization datasets for annual global carbon budgets", "abstract": "Abstract. Land-use change has been the dominant source of anthropogenic carbon emissions for most of the historical period and is currently one of the largest and most uncertain components of the global carbon cycle. Advancing the scientific understanding on this topic requires that the best data be used as input to state-of-the-art models in well-organized scientific assessments. The Land-Use Harmonization 2 dataset (LUH2), previously developed and used as input for simulations of the 6th Coupled Model Intercomparison Project (CMIP6), has been updated annually to provide required input to land models in the annual Global Carbon Budget (GCB) assessments. Here we discuss the methodology for producing these annual LUH2-GCB updates and extensions which incorporate annual wood harvest data updates from the Food and Agriculture Organization (FAO) of the United Nations for dataset years after 2015 and the History Database of the Global Environment (HYDE) gridded cropland and grazing area data updates (based on annual FAO cropland and grazing area data updates) for dataset years after 2012, along with extrapolations to the current year due to a lag of 1 or more years in the FAO data releases. The resulting updated LUH2-GCB datasets have provided global, annual gridded land-use and land-use-change data relating to agricultural expansion, deforestation, wood harvesting, shifting cultivation, regrowth and afforestation, crop rotations, and pasture management and are used by both bookkeeping models and dynamic global vegetation models (DGVMs) for the GCB. For GCB 2019, a more significant update to LUH2 was produced, LUH2-GCB2019 (https://doi.org/10.3334/ORNLDAAC/1851, Chini et al., 2020b), to take advantage of new data inputs that corrected cropland and grazing areas in the globally important region of Brazil as far back as 1950. From 1951 to 2012 the LUH2-GCB2019 dataset begins to diverge from the version of LUH2 used for the World Climate Research Programme's CMIP6, with peak differences in Brazil in the year 2000 for grazing land (difference of 100 000 km2) and in the year 2009 for cropland (difference of 77 000 km2), along with significant sub-national reorganization of agricultural land-use patterns within Brazil. The LUH2-GCB2019 dataset provides the base for future LUH2-GCB updates, including the recent LUH2-GCB2020 dataset, and presents a starting point for operationalizing the creation of these datasets to reduce time lags due to the multiple input dataset and model latencies.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/GMD-15-3281-2022", "year": 2022, "title": "Development and evaluation of an advanced National Air Quality Forecasting Capability using the NOAA Global Forecast System version 16", "abstract": "Abstract. A new dynamical core, known as the Finite-Volume Cubed-Sphere (FV3) and developed at both NASA and NOAA, is used in NOAA's Global Forecast System (GFS) and in limited-area models for regional weather and air quality applications. NOAA has also upgraded the operational FV3GFS to version 16 (GFSv16), which includes a number of significant developmental advances to the model configuration, data assimilation, and underlying model physics, particularly for atmospheric composition to weather feedback. Concurrent with the GFSv16 upgrade, we couple the GFSv16 with the Community Multiscale Air Quality (CMAQ) model to form an advanced version of the National Air Quality Forecasting Capability (NAQFC) that will continue to protect human and ecosystem health in the US. Here we describe the development of the FV3GFSv16 coupling with a state-of-the-science CMAQ model version 5.3.1. The GFSCMAQ coupling is made possible by the seminal version of the NOAA-EPA AtmosphereChemistry Coupler (NACC), which became a major piece of the next operational NAQFC system (i.e., NACC-CMAQ) on 20 July 2021. NACC-CMAQ has a number of scientific advancements that include satellite-based data acquisition technology to improve land cover and soil characteristics and inline wildfire smoke and dust predictions that are vital to predictions of fine particulate matter (PM2.5) concentrations during hazardous events affecting society, ecosystems, and human health. The GFS-driven NACC-CMAQ model has significantly different meteorological and chemical predictions compared to the previous operational NAQFC, where evaluation of NACC-CMAQ shows generally improved near-surface ozone and PM2.5 predictions and diurnal patterns, both of which are extended to a 72 h (3 d) forecast with this system.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/S41612-018-0040-X", "year": 2018, "title": "Short Black Carbon lifetime inferred from a global set of aircraft observations", "abstract": "Black Carbon (BC) aerosols substantially affect the global climate. However, accurate simulation of BC atmospheric transport remains elusive, due to shortcomings in modeling and a shortage of constraining measurements. Recently, several studies have compared simulations with observed vertical concentration profiles, and diagnosed a global-mean BC atmospheric residence time of <5 days. These studies have, however, been focused on limited geographical regions, and used temporally and spatially coarse model information. Here we expand on previous results by comparing a wide range of recent aircraft measurements from multiple regions, including the Arctic and the Atlantic and Pacific oceans, to simulated distributions obtained at varying spatial and temporal resolution. By perturbing BC removal processes and using current best-estimate emissions, we confirm a constraint on the global-mean BC lifetime of <5.5 days, shorter than in many current global models, over a broader geographical range than has so far been possible. Sampling resolution influences the results, although generally without introducing major bias. However, we uncover large regional differences in the diagnosed lifetime, in particular in the Arctic. We also find that only a weak constraint can be placed in the African outflow region over the South Atlantic, indicating inaccurate emission sources or model representation of transport and microphysical processes. While our results confirm that BC lifetime is shorter than predicted by most recent climate models, they also cast doubt on the usability of the concept of a global-mean BC lifetime for climate impact studies, or as an indicator of model skill.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-7-1193-2007", "year": 2007, "title": "The influence of African air pollution on regional and global tropospheric ozone", "abstract": "Abstract. We investigate the influence of African biomass burning, biogenic, lightning and anthropogenic emissions on the tropospheric ozone over Africa and globally using a coupled global chemistry climate model. Our model studies indicate that surface ozone concentration may rise by up to 50 ppbv in the burning region during the biomass burning seasons. Biogenic emissions yield between 530 ppbv increase in the near surface ozone concentration over tropical Africa. The impact of lightning on surface ozone is negligible, while anthropogenic emissions yield a maximum of 7 ppbv increase in the annual-mean surface ozone concentration over Nigeria, South Africa and Egypt. Our results show that biogenic emissions are the most important African emission source affecting total tropospheric ozone. The influence of each of the African emissions on the global tropospheric ozone burden (TOB) of 384 Tg yields about 9.5 Tg, 19.6 Tg, 9.0 Tg and 4.7 Tg for biomass burning, biogenic, lightning and anthropogenic emissions emitted in Africa respectively. The impact of each of these emission categories on African TOB of 33 Tg is 2.5 Tg, 4.1 Tg, 1.75 Tg and 0.89 Tg respectively, which together represents about 28% of the total TOB calculated over Africa. Our model calculations also suggest that more than 70% of the tropospheric ozone produced by each of the African emissions is found outside the continent, thus exerting a noticeable influence on a large part of the tropical troposphere. Apart from the Atlantic and Indian Ocean, Latin America experiences the largest impact of African emissions, followed by Oceania, the Middle East, Southeast and south-central Asia, northern North America (i.e. the United States and Canada), Europe and north-central Asia, for all the emission categories.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-22-7905-2022", "year": 2022, "title": "Record-breaking dust loading during two mega dust storm events over northern China in March 2021: aerosol optical and radiative properties and meteorological drivers", "abstract": "Abstract. Although a remarkable reduction in the frequency of sand and dust storms (SDSs) in the past several decades has been reported over northern China (NC), two unexpected mega SDSs occurred on 1520 and 2729 March 2021 (abbreviated as the 3.15 and 3.27 SDS events), which has reawakened widespread concern. This study characterizes the optical, microphysical, and radiative properties of aerosols and their meteorological drivers during these two SDS events using the Sun photometer observations in Beijing and a comprehensive set of multiple satellite (including MODIS, VIIRS, CALIOP, and Himawari-8) and ground-based observations (including the CMA visibility network and AD-Net) combined with atmospheric reanalysis data. Moreover, a long-term (20002021) dust optical depth (DOD) dataset retrieved from MODIS measurements was also utilized to evaluate the historical ranking of the dust loading in NC during dust events. During the 3.15 and 3.27 events, the invasion of dust plumes greatly degraded the visibility over large areas of NC, with extreme low visibility of 50 and 500 m recorded at most sites on 15 and 28 March, respectively. Despite the shorter duration of the 3.27 event relative to the 3.15 event, sun photometer and satellite observations in Beijing recorded a larger peak AOD (2.5) in the former than in the latter (2.0), which was mainly attributed to the short-term intrusion of coarse-mode dust particles with larger effective radii (1.9 m) and volume concentrations (2.0 m3 m2) during the 3.27 event. The shortwave direct aerosol radiative forcing induced by dust was estimated to be 92.1 and 111.4 W m2 at the top of the atmosphere, 184.7 and 296.2 W m2 at the surface, and +92.6 and +184.8 W m2 in the atmosphere in Beijing during the 3.15 and 3.27 events, respectively. CALIOP observations show that during the 3.15 event the dust plume was lifted to an altitude of 48 km, and its range of impact extended from the dust source to the eastern coast of China. In contrast, the lifting height of the dust plume during the 3.27 event was lower than that during the 3.15 event, which was also confirmed by ground-based lidar observations. The MODIS-retrieved DOD data registered these two massive SDS events as the most intense episode in the same period in history over the past 2 decades. These two extreme SDS events were associated with both atmospheric circulation extremes and local meteorological anomalies that favored enhanced dust emissions in the Gobi Desert (GD) across southern Mongolia and NC. Meteorological analysis revealed that both SDS events were triggered by an exceptionally strong Mongolian cyclone generated at nearly the same location (along the central and eastern plateau of Inner Mongolia) in conjunction with a surface-level cold high-pressure system at the rear, albeit with differences in magnitude and spatial extent of impact. In the GD, the early melting of spring snow caused by near-surface temperature anomalies over dust source regions, together with negative soil moisture anomalies induced by decreased precipitation, formed drier and barer soil surfaces, which allowed for increased emissions of dust into the atmosphere by strongly enhanced surface winds generated by the Mongolian cyclone.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ENVPOL.2018.09.026", "year": 2018, "title": "Using MAIAC AOD to verify the PM2. 5 spatial patterns of a land use regression model", "abstract": "Accurate spatial information of PM2.5 is critical for air pollution control and epidemiological studies. Land use regression (LUR) models have been widely used for predicting spatial distribution of ground PM2.5. However, the predicted PM2.5 spatial patterns of a LUR model has not been adequately examined due to limited ground observations. The increasing aerosol optical depth (AOD) products might be an approximation of spatially continuous observation across large areas. This study established the relationship between seasonal 1 km 1 km MAIAC AOD and observed ground PM2.5 in Beijing, and then seasonal PM2.5 maps were predicted based on AOD. Seasonal LUR models were also developed, and both the AOD and LUR models were validated by hold-out monitoring sites. Finally, the spatial patterns of LUR models were comprehensively verified by the above AOD PM2.5 maps. The results showed that AOD alone could be used directly to predict the spatial distribution of ground PM2.5 concentration at seasonal level (R2 0.53 in model fitting and testing), which was comparable with the capability of LUR models (R2 0.81 in model fitting and testing). PM2.5 maps derived from the two methods showed similar spatial trend and coordinated variations near traffic roads. Large discrepancies could be observed at urban-rural transition areas where land use characters varied quickly. Variable and buffer size selection was critical for LUR model as they dominated the spatial patterns of predicted PM2.5. Incorporating AOD into LUR model could improve model performance in spring season and provide more reliable results during testing.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ECOLIND.2021.108287", "year": 2021, "title": "Determining the contribution of environmental factors in controlling dust pollution during cold and warm months of western Iran using different data mining \u2026", "abstract": "Dust pollution is one of the major environmental crises in the arid regions of Iran and there is a need to predict dust pollution and identify its controlling factors to help reduce its adverse effects on the livelihood of residents of these areas. Although deep neural networks (DNN) are powerful tools in the modelling of environmental phenomena, they are recognized as being challenging to interpret due to their black-box nature. To address this issue and understand the importance of each environmental control on dust pollution, game theory (i.e., Shapley values) was used to better understand the performance and interpretability of DNN models. Here, monthly mean values of precipitation, air temperature, surface wind speed, potential evapotranspiration, normalized difference vegetation index, normalized difference salinity index, Palmer drought severity index, soil heat flux, and surface pressure were selected as explanatory variables. The dust storm index (DSI), an indicator of dust pollution, was the predicted response variable for the cold and warm months. The results showed that the accuracies of the DNN model in predicting cold months DSI (CMDSI) and warm months DSI (WMDSI) were higher compared to other traditional machine learning algorithms. DNN model increased the R2 by 13% and 15% for predicting CMDSI and WMDSI, respectively, compared to the Random Forest model, which was the second most effective approach. According to the Shapley values, the most important controls on the occurrence of dust storms during the cold months of the study period (20002018) were wind speed, soil heat flux, and precipitation. During the warm months, wind speed was the most important controlling factor and was followed by precipitation, soil heat flux, and potential evapotranspiration. Overall, the results demonstrate the effectiveness of the DNN model and game theory in identifying the factors affecting dust pollution, which may help mitigate its impacts on the residents of western Iran.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2020JD032974", "year": 2020, "title": "The Vulcan Version 3.0 High\u2010Resolution Fossil Fuel CO2 Emissions for the United States", "abstract": "Estimates of high-resolution greenhouse gas (GHG) emissions have become a critical component of climate change research and an aid to decision makers considering GHG mitigation opportunities. The \"Vulcan Project\" is an effort to estimate bottom-up carbon dioxide emissions from fossil fuel combustion and cement production (FFCO2) for the U.S. landscape at space and time scales that satisfy both scientific and policy needs. Here, we report on the Vulcan version 3.0 which quantifies emissions at a resolution of 1 km2/hr for the 2010-2015 time period. We estimate 2011 FFCO2 emissions of 1,589.9 TgC with a 95% confidence interval of 1,367/1,853 TgC (-14.0%/+16.6%), implying a one-sigma uncertainty of ~ \u00b18%. Per capita emissions are larger in states dominated by electricity production and industrial activity and smaller where onroad and building emissions dominate. The U.S. FFCO2 emissions center of mass (CoM) is located in the state of Missouri with mean seasonality that moves on a near-elliptical NE/SW path. Comparison to ODIAC, a global gridded FFCO2 emissions estimate, shows large total emissions differences (100.4 TgC for year 2011), a spatial correlation of 0.68 (R2), and a mean absolute relative difference at the 1 km2 scale of 104.3%. The Vulcan data product offers a high-resolution estimate of FFCO2 emissions in every U.S. city, obviating costly development of self-reported urban inventories. The Vulcan v3.0 annual gridded emissions data product can be downloaded from the Oak Ridge National Laboratory Distributed Active Archive Center (Gurney, Liang, et al., 2019, https://doi.org/10.3334/ORNLDAAC/1741).", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S11783-019-1202-8", "year": 2020, "title": "PM2. 5 over North China based on MODIS AOD and effect of meteorological elements during 2003\u20132015", "abstract": "Over the past 40 years, PM2.5 pollution in North China has become increasingly serious and progressively exposes the densely populated areas to pollutants However, due to limited ground data, it is challenging to estimate accurate PM2.5 exposure levels, further making it unfavorable for the prediction and prevention of PM2.5 pollutions. This paper therefore uses the mixed effect model to estimate daily PM2.5 concentrations of North China between 2003 and 2015 with ground observation data and MODIS AOD satellite data. The tempo-spatial characteristics of PM2.5 and the influence of meteorological elements on PM2.5 is discussed with EOF and canonical correlation analysis respectively. Results show that overall R2 is 0.36 and the root mean squared predicted error was 30.1 g/m3 for the model prediction. Our time series analysis showed that, the Taihang Mountains acted as a boundary between the high and low pollution areas in North China; while the northern part of Henan Province, the southern part of Hebei Province and the western part of Shandong Province were the most polluted areas. Although, in 2004, 2009 and dates after 2013, PM2.5 concentrations were relatively low. Meteorological/topography conditions, that include high surface humidity of area in the range of 3440N and 119124E, relatively low boundary layer heights, and southerly and easterly winds from the east and north area were common factors attributed to haze in the most polluted area. Overall, the spatial distribution of increasingly concentrated PM2.5 pollution in North China are consistent with the local emission level, unfavorable meteorological conditions and topographic changes.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/RS13040758", "year": 2021, "title": "Estimating the Daily NO2 Concentration with High Spatial Resolution in the Beijing\u2013Tianjin\u2013Hebei Region Using an Ensemble Learning Model", "abstract": "Nitrogen dioxide (NO2) is an important pollutant related to human activities, which has short-term and long-term effects on human health. An ensemble learning model was constructed and applied to estimate daily NO2 concentrations in the BeijingTianjinHebei region between 2010 and 2016. A variety of predictive variables included satellite-based troposphere NO2 vertical column concentration, meteorology, elevation, gross domestic product (GDP), population, land-use variables, and road network. The ensemble learning model achieved two things: a 0.01 0.01 grid resolution and the estimation of historical data for the years 20102013. The ensemble model showed good performance, whereby the R2 of tenfold cross-validation was 0.72 and the R2 of test validation was 0.71. Meteorological hysteretic effects were incorporated into the model, where the one-day lagged boundary layer height contributed the most. The annual NO2 estimation showed little change from 2010 to 2016. The seasonal NO2 estimation from highest to lowest occurred in winter, autumn, spring, and summer. In the annual maps and seasonal maps, the NO2 estimations in the northwest region were lower than those in the southeast region, and there was a heavily polluted band in the south of the Taihang Mountains. In coastal areas, the annual NO2 estimations were higher than the NO2 monitored values. The drawback of the model is underestimation at high values and overestimation at low values. This study indicates that the ensemble learning model has excellent performance in the simulation of NO2 with high spatial and temporal resolution. Furthermore, the research framework in this study can be a generally applied for drawing implications for other regions, especially for other cities in China.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-13-4841-2020", "year": 2020, "title": "1.5 years of TROPOMI CO measurements: comparisons to MOPITT and ATom", "abstract": "Abstract. We have analyzed TROPOspheric Monitoring Instrument (TROPOMI) carbon monoxide (CO) data acquired between November 2017 and March 2019 with respect to other satellite (MOPITT, Measurement Of Pollution In The Troposphere) and airborne (ATom, Atmospheric Tomography mission) datasets to better understand TROPOMI's contribution to the global tropospheric CO record (2000 to present). MOPITT and TROPOMI are two of only a few satellite instruments to ever derive CO from solar-reflected radiances. Therefore, it is particularly important to understand how these two datasets compare. Our results indicate that TROPOMI CO retrievals over land show excellent agreement with respect to MOPITT: relative biases and their SD (i.e., accuracy and precision) are on average -3.73%11.51%, -2.24%12.38%, and -3.22%11.13% compared to the MOPITT TIR (thermal infrared), NIR (near infrared), and TIR + NIR (multispectral) products, respectively. TROPOMI and MOPITT data also show good agreement in terms of temporal and spatial patterns. Despite depending on solar-reflected radiances for its measurements, TROPOMI can also retrieve CO over bodies of water if clouds are present by approximating partial columns under cloud tops using scaled, model-based reference CO profiles. We quantify the bias of TROPOMI total column retrievals over bodies of water with respect to colocated in situ ATom CO profiles after smoothing the latter with the TROPOMI column averaging kernels (AKs), which account for signal attenuation under clouds (relative bias and its SD =3.25%11.46 %). In addition, we quantify enull (the null-space error), which accounts for differences between the shape of the TROPOMI reference profile and that of the ATom true profile (enull=2.16%2.23 %). For comparisons of TROPOMI and MOPITT retrievals over open water we compare TROPOMI total CO columns to their colocated MOPITT TIR counterparts. Relative bias and its SD are 2.98 %15.71 % on average. We investigate the impact of discrepancies between the a priori and reference CO profiles (used by MOPITT and TROPOMI, respectively) on CO retrieval biases by applying a null-space adjustment (based on the MOPITT a priori) to the TROPOMI total column values. The effect of this adjustment on MOPITT and TROPOMI biases is minor, typically 12 percentage points.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-19-327-2019", "year": 2019, "title": "Quantification and evaluation of atmospheric pollutant emissions from open biomass burning with multiple methods: a case study for the Yangtze River Delta \u2026", "abstract": "Abstract. Air pollutant emissions from open biomass burning (OBB) in the Yangtze River Delta (YRD) were estimated for 20052015 using three (traditional bottom-up, fire radiative power (FRP), and constraining) approaches, and the differences among those methods and their sources were analyzed. The species included PM10, PM2.5, organic carbon (OC), elemental carbon (EC), CH4, non-methane volatile organic compounds (NMVOCs), CO, CO2, NOx, SO2 and NH3. The interannual trends in emissions with FRP-based and constraining methods were similar to the fire counts in 20052012, while those with the traditional method were not. For most years, emissions of all species estimated with the constraining method were smaller than those with the traditional method except for NMVOCs, while they were larger than those with the FRP-based method except for EC, CH4 and NH3. Such discrepancies result mainly from different masses of crop residue burned in the field (CRBF) estimated in the three methods. Chemistry transport modeling (CTM) was applied using the three OBB inventories. The simulated PM10 concentrations with constrained emissions were closest to the available observations, implying that the constraining method provided the best emission estimates. CO emissions in the three methods were compared with other studies. Similar temporal variations were found for the constrained emissions, FRP-based emissions, GFASv1.0 and GFEDv4.1s, with the largest and the lowest emissions estimated for 2012 and 2006, respectively. The temporal variations in the emissions based on the traditional method, GFEDv3.0, and the method of Xia et al. (2016) were different. The constrained CO emissions in this study were commonly smaller than those based on the traditional bottom-up method and larger than those based on burned area or FRP in other studies. In particular, the constrained emissions were close to GFEDv4.1s that contained emissions from small fires. The contributions of OBB to two particulate pollution events in 2010 and 2012 were analyzed with the brute-force method. Attributed to varied OBB emissions and meteorology, the average contribution of OBB to PM10 concentrations in 814 June 2012 was estimated at 37.6 % (56.7 g m3), larger than that in 1724 June 2010 at 21.8 % (24.0 g m3). Influences of diurnal curves of OBB emissions and meteorology on air pollution caused by OBB were evaluated by designing simulation scenarios, and the results suggested that air pollution caused by OBB would become heavier if the meteorological conditions were unfavorable and that more attention should be paid to the OBB control at night. Quantified with Monte Carlo simulation, the uncertainty of the traditional bottom-up inventory was smaller than that of the FRP-based one. The percentages of CRBF and emission factors were the main source of uncertainty for the two approaches. Further improvement on CTM for OBB events would help better constrain OBB emissions.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-22-1131-2022", "year": 2022, "title": "Contribution of traffic-originated nanoparticle emissions to regional and local aerosol levels", "abstract": "Abstract. Sub-50 nm particles originating from traffic emissions pose risks to human health due to their high lung deposition efficiency and potentially harmful chemical composition. We present a modeling study using an updated European Aerosol Cloud Climate and Air Quality Interactions (EUCAARI) number emission inventory, incorporating a more realistic, empirically justified particle size distribution (PSD) for sub-50 nm particles from road traffic as compared with the previous version. We present experimental PSDs and CO2 concentrations, measured in a highly trafficked street canyon in Helsinki, Finland, as an emission factor particle size distribution (EFPSD), which was then used in updating the EUCAARI inventory. We applied the updated inventory in a simulation using the regional chemical transport model PMCAMx-UF over Europe for May 2008. This was done to test the effect of updated emissions at regional and local scales, particularly in comparison with atmospheric new particle formation (NPF). Updating the inventory increased the simulated average total particle number concentrations by only 1 %, although the total particle number emissions were increased to a 3-fold level. The concentrations increased up to 11 % when only 1.33 nm sized particles (nanocluster aerosol, NCA) were considered. These values indicate that the effect of updating overall is insignificant at a regional scale during this photochemically active period. During this period, the fraction of the total particle number originating from atmospheric NPF processes was 91 %; thus, these simulations give a lower limit for the contribution of traffic to the aerosol levels. Nevertheless, the situation is different when examining the effect of the update closer spatially or temporally or when focusing on the chemical composition or the origin of the particles. For example, the daily average NCA concentrations increased by a factor of several hundred or thousand in some locations on certain days. Overall, the most significant effects reaching several orders of magnitude from updating the inventory are observed when examining specific particle sizes (especially 720 nm), particle components, and specific urban areas. While the model still has a tendency to predict more sub-50 nm particles compared to the observations, the most notable underestimations in the concentrations of sub-10 nm particles are now overcome. Additionally, the simulated distributions now agree better with the data observed at locations with high traffic densities. The findings of this study highlight the need to consider emissions, PSDs, and composition of sub-50 nm particles from road traffic in studies focusing on urban air quality. Updating this emission source brings the simulated aerosol levels, particularly in urban locations, closer to observations, which highlights its importance for calculations of human exposure to nanoparticles.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/NGEO2482", "year": 2015, "title": "Amplified melt and flow of the Greenland ice sheet driven by late-summer cyclonic rainfall", "abstract": "Intense rainfall events significantly affect Alpine and Alaskan glaciers through enhanced melting, ice-flow acceleration and subglacial sediment erosion, yet their impact on the Greenland ice sheet has not been assessed. Here we present measurements of ice velocity, subglacial water pressure and meteorological variables from the western margin of the Greenland ice sheet during a week of warm, wet cyclonic weather in late August and early September 2011. We find that extreme surface runoff from melt and rainfall led to a widespread acceleration in ice flow that extended 140 km into the ice-sheet interior. We suggest that the late-season timing was critical in promoting rapid runoff across an extensive bare ice surface that overwhelmed a subglacial hydrological system in transition to a less-efficient winter mode. Reanalysis data reveal that similar cyclonic weather conditions prevailed across southern and western Greenland during this time, and we observe a corresponding ice-flow response at all land- and marine-terminating glaciers in these regions for which data are available. Given that the advection of warm, moist air masses and rainfall over Greenland is expected to become more frequent in the coming decades, our findings portend a previously unforeseen vulnerability of the Greenland ice sheet to climate change.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S41063-018-0045-Z", "year": 2018, "title": "New insights into sea ice changes over the past 2.2 kyr in Disko Bugt, West Greenland", "abstract": "Past sea ice conditions and open water phytoplankton production were reconstructed from a sediment core taken in Disko Bugt, West Greenland, using the sea ice biomarker IP25 and other specific phytoplankton biomarker (i.e., brassicasterol, dinosterol, HBI III) records. Our biomarker record indicates that Disko Bugt experienced a gradual expansion of seasonal sea ice during the last 2.2 kyr. Maximum sea ice extent was reached during the Little Ice Age around 0.2 kyr BP. Superimposed on this longer term trend, we find short-term oscillations in open water primary production and terrigenous input, which may be related to the Atlantic Multidecadal Oscillation and solar activity changes as potential climatic trigger mechanisms. A direct sample-to-sample multiproxy comparison of our new biomarker record with microfossil (i.e., benthic foraminifera, dinocysts, and diatoms) and other geochemical records (i.e., alkenone biomarkers) indicates that different proxies are influenced by the complex environmental system with pronounced seasonal changes and strong oceanographic gradients, e.g., freshwater inflow from the Greenland Ice Sheet. Differences in sea ice reconstructions may indicate that the IP25 record reflects only the relatively short sea ice season (spring), whereas other microfossil reconstructions may reflect a longer (springautumn) interval.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-4473-2022", "year": 2022, "title": "A comparison between Envisat and ICESat sea ice thickness in the Southern Ocean", "abstract": "Abstract. The crucial role that Antarctic sea ice plays in the global climate system is strongly linked to its thickness. While field observations are too sparse in the Southern Ocean to determine long-term trends of the Antarctic sea ice thickness (SIT) on a hemispheric scale, satellite radar altimetry data can be applied with a promising prospect. The European Space Agency's Sea Ice Climate Change Initiative project (ESA SICCI) generates sea ice thickness derived from Envisat, covering the entire Southern Ocean year-round from 2002 to 2012. In this study, the SICCI Envisat Antarctic SIT is first compared with an Ice, Cloud, and land Elevation Satellite (ICESat) SIT product retrieved with a modified ice density algorithm. Both data sets are compared to SIT estimates from upward-looking sonar (ULS) in the Weddell Sea, showing mean differences (MDs) and standard deviations (SDs, in parentheses) of 1.29 (0.65) m for Envisat ULS ( denotes minus and the same below), while we find 1.11 (0.81) m for ICESat ULS. The inter-comparisons are conducted for all seasons except for winter, based on the ICESat operating periods. According to the results, the differences between Envisat and ICESat SIT reveal significant temporal and spatial variations. More specifically, the smallest seasonal SIT MD (SD) of 0.00 m (0.39 m) for Envisat ICESat is found in spring (OctoberNovember), while a larger MD (SD) of 0.52 (0.68 m) and 0.57 m (0.45 m) exists in summer (FebruaryMarch) and autumn (MayJune). It is also shown that from autumn to spring, mean Envisat SIT decreases while mean ICESat SIT increases. Our findings suggest that both overestimation of Envisat sea ice freeboard potentially caused by radar backscatter originating from inside the snow layer and the Advanced Microwave Scanning Radiometer for EOS (AMSR-E, where EOS stands for Earth Observing System) snow depth biases and sea ice density uncertainties can possibly account for the differences between Envisat and ICESat SIT.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1038/S41598-022-15440-Y", "year": 2022, "title": "Total isostatic response to the complete unloading of the Greenland and Antarctic Ice Sheets", "abstract": "The land surface beneath the Greenland and Antarctic Ice Sheets is isostatically suppressed by the mass of the overlying ice. Accurate computation of the land elevation in the absence of ice is important when considering, for example, regional geodynamics, geomorphology, and ice sheet behaviour. Here, we use contemporary compilations of ice thickness and lithospheric effective elastic thickness to calculate the fully re-equilibrated isostatic response of the solid Earth to the complete removal of the Greenland and Antarctic Ice Sheets. We use an elastic plate flexure model to compute the isostatic response to the unloading of the modern ice sheet loads, and a self-gravitating viscoelastic Earth model to make an adjustment for the remaining isostatic disequilibrium driven by ice mass loss since the Last Glacial Maximum. Feedbacks arising from water loading in areas situated below sea level after ice sheet removal are also taken into account. In addition, we quantify the uncertainties in the total isostatic response associated with a range of elastic and viscoelastic Earth properties. We find that the maximum change in bed elevation following full re-equilibration occurs over the centre of the landmasses and is +783 m in Greenland and +936 m in Antarctica. By contrast, areas around the ice margins experience up to 123 m of lowering due to a combination of sea level rise, peripheral bulge collapse, and water loading. The computed isostatic response fields are openly accessible and have a number of applications for studying regional geodynamics, landscape evolution, cryosphere dynamics, and relative sea level change.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ENVSCI.2021.09.005", "year": 2021, "title": "Using Decision Making under Deep Uncertainty (DMDU) approaches to support climate change adaptation of Swiss Ski Resorts", "abstract": "Climate change threatens winter tourism in the Alps severely, and ski resorts are struggling to cope under uncertain climate change. We aim to identify under what conditions physical and economic tipping points for ski resorts may occur under changing climate in six Swiss ski resorts representing low, medium, and high elevation in the Alps. We use exploratory modeling (EMA) to assess climate change impacts on ski resorts under a range of futures adaptation options: (1) snowmaking and (2) diversifying the ski resorts' activities throughout the year. High-resolution climate projections (CH2018) were used to represent climate uncertainty. To improve the coverage of the uncertainty space and account for the climate models' intra-annual variability, we produced new climate realizations using resampling techniques. We demonstrate the importance of five factors, namely climate scenarios (RCPs), intra-annual climate variability, snow processes model, and two adaptation options, in ski resorts survival under a wide range of future scenarios. In six ski resorts, strong but highly variable decreases in the future number of days with good snow conditions for skiing (GSD) are projected. However, despite the different characteristics of the resorts, responses are similar and a shrunk of up to 31, 50, and 62 days in skiing season (Dec-April) is projected for the near-future (20202050), mid-future (20502080), and far-future (20702100), respectively. Similarly, in all cases, the number of days with good conditions for snowmaking (GDSM) will reduce up to 30, 50, and 74 days in the skiing season in the near-, mid-, and far-future horizons, respectively. We indicate that all ski resorts will face a reduction of up to 13%, 33%, and 51% of their reference period (19812010) revenue from winter skiing activities in the near-, mid-, and far-future horizons. Based on the outcomes of the EMA, we identify Dynamic Adaptive Policy Pathways (DAPP) and determine the adaptation options that ski resorts could implement to avoid tipping points in the future. We highlight the advantages of adaptive planning in a first of its kind application of DMDU techniques to winter tourism. We specify the possible adaptation options ranging from \"low revenue diversification and moderate snowmaking\" to \"high revenue diversification and large snowmaking\" and demonstrate when an adaptation action fails and a change to a new plan is needed. By the end of the century, we show that only ski resorts with ski lines above 18002000 m elevation will survive regardless of the climate scenarios. Our approach to decision-making is highly flexible and can easily be extended to other ski resorts and account for additional adaptation options.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1017/JOG.2016.77", "year": 2016, "title": "Changes in ice-shelf buttressing following the collapse of Larsen A Ice Shelf, Antarctica, and the resulting impact on tributaries", "abstract": "The dominant mass-loss process on the Antarctic Peninsula has been ice-shelf collapse, including the Larsen A Ice Shelf in early 1995. Following this collapse, there was rapid speed up and thinning of its tributary glaciers. We model the impact of this ice-shelf collapse on upstream tributaries, and compare with observations using new datasets of surface velocity and ice thickness. Using a two-horizontal-dimension shallow shelf approximation model, we are able to replicate the observed large increase in surface velocity that occurred within Drygalski Glacier, Antarctic Peninsula. The model results show an instantaneous twofold increase in flux across the grounding line, caused solely from the reduction in backstress through ice shelf removal. This demonstrates the importance of ice-shelf buttressing for flow upstream of the grounding line and highlights the need to explicitly include lateral stresses when modelling real-world settings. We hypothesise that further increases in velocity and flux observed since the ice-shelf collapse result from transient mass redistribution effects. Reproducing these effects poses the next, more stringent test of glacier and ice-sheet modelling studies.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1038/S41561-022-01097-9", "year": 2023, "title": "Episodic dynamic change linked to damage on the thwaites glacier ice tongue", "abstract": "The stability and dynamics of Thwaites Glacier depend on the structural properties of its marine terminus; however, the relationship between these variables on the floating ice tongue is poorly understood. Here we present a six-year record of ice speed, derived from satellite observations starting in 2015, showing two large-magnitude (approximately 3045%) and prolonged (approximately one to two years) cycles of speed variation across the ice tongue. Using an automated, deep learning-based method of extracting high-resolution fracture maps from satellite imagery, we detail periods of increasing fracture development and subsequent reconsolidation in the ice tongue shear margin that coincide with the observed speed changes. Inverse modelling using the BISICLES ice-sheet model indicates that the variation in ice speed can be accounted for by these observed changes to the spatial pattern of fracturing. This study provides further evidence of direct coupling between fracturing and dynamic variability in West Antarctica but indicates that increased fracturing and associated speed changes are reversible on one- to two-year timescales. We suggest that fracturing does not necessarily lead to positive feedback with glacier acceleration on these timescales and that damage process modelling is important for accurately predicting the evolution of the Antarctic Ice Sheet.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3189/2013AOG64A110", "year": 2013, "title": "Subglacial bathymetry and sediment layer distribution beneath the Pine", "abstract": "Abstract\r\n Pine Island Glacier (PIG), West Antarctica, has been experiencing acceleration in its flow speed and mass loss for nearly two decades, driven in part by an increase in the delivery of relatively warm Circumpolar Deep Water (CDW). However, at present, the configuration of the sub-ice-shelf cavity and bed conditions beneath the PIG ice shelf that dictate such oceanic influences remain poorly understood. Here, we use aerogravity data and ocean bottom depths measured by an autonomous underwater vehicle (AUV) to model the bathymetry and sediment layer thickness beneath the PIG ice shelf. Results reveal that the deep basins, previously found by AUV on both landward and seaward sides of a submarine ridge, extend substantially to the north and south. The water column thickness of the basins reaches 400-550 m on the landward side of the ridge and 500-600 m on the seaward side. The sediment layer covers the whole expanse of the seabed beneath the ice shelf, and the thickness is in the range 200-1000 m. The thinnest sediments (<200 m) are found on the seaward slope of the submarine ridge, suggesting that erosion by advancing ice may have been concentrated in the lee of the topographic high.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-17-175-2023", "year": 2023, "title": "Snow stratigraphy observations from Operation IceBridge surveys in Alaska using S and C band airborne ultra-wideband FMCW (frequency-modulated continuous wave) radar", "abstract": "Abstract. During the concluding phase of the NASA Operation\nIceBridge (OIB), we successfully completed two airborne measurement\ncampaigns (in 2018 and 2021, respectively) using a compact S and C band radar\ninstalled on a Single Otter aircraft and collected data over Alaskan\nmountains, ice fields, and glaciers. This paper reports seasonal snow depths\nderived from radar data. We found large variations in seasonal\nradar-inferred depths with multi-modal distributions assuming a constant\nrelative permittivity for snow equal to 1.89. About 34 % of the snow\ndepths observed in 2018 were between 3.2 and 4.2 m, and close to 30 % of the\nsnow depths observed in 2021 were between 2.5 and 3.5 m. We observed snow\nstrata in ice facies, combined percolation and wet-snow facies, and dry-snow facies from\nradar data and identified the transition areas from wet-snow facies to ice\nfacies for multiple glaciers based on the snow strata and radar\nbackscattering characteristics. Our analysis focuses on the measured strata\nof multiple years at the caldera of Mount Wrangell (K'elt'aeni) to estimate the local\nsnow accumulation rate. We developed a method for using our radar readings\nof multi-year strata to constrain the uncertain parameters of interpretation\nmodels with the assumption that most of the snow layers detected by the\nradar at the caldera are annual accumulation layers. At a 2004 ice core and\n2005 temperature sensor tower site, the locally estimated average snow\naccumulation rate is 2.89 m w.e. a1 between the years\n2003 and 2021. Our estimate of the snow accumulation rate between 2005 and\n2006 is 2.82 m w.e. a1, which matches closely to the 2.75 m w.e. a1 inferred from independent ground-truth measurements made the same\nyear. The snow accumulation rate between the years 2003 and 2021 also showed\na linear increasing trend of 0.011 m w.e. a2. This trend is\ncorroborated by comparisons with the surface mass balance (SMB) derived for\nthe same period from the regional atmospheric climate model MAR (Modele\nAtmospherique Regional). According to MAR data, which show an\nincrease of 0.86 C in this area for the period of 20032021, the\nlinear upward trend is associated with the increase in snowfall and rainfall\nevents, which may be attributed to elevated global temperatures. The\nfindings of this study confirmed the viability of our methodology, as well\nas its underlying assumptions and interpretation models.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S11442-019-1585-2", "year": 2019, "title": "Glacier and snow variations and their impacts on regional water resources in mountains", "abstract": "Glaciers and snow are major constituents of solid water bodies in mountains; they can regulate the stability of local water sources. However, they are strongly affected by climate change. This study focused on the Tianshan Mountains, using glacier and snow datasets to analyse variations in glaciers, snow, water storage, and runoff. Three typical river basins (Aksu, Kaidou, and Urumqi Rivers) were selected to interpret the impacts of glacier and snow changes on regional water resources in the Tianshan Mountains. The results exhibited a nonlinear functional relationship between glacial retreat rate and area, demonstrating that small glacial retreat is more sensitive under climate change. Further, the glacial retreat rate at the low-middle elevation zone was seen to be faster than that at the high elevation zone. The regional average terrestrial water storage (TWS) decrease rate in the Tianshan Mountains was0.71.53 cm/a during 20032015. The highest TWS deficit region was located in the central part of the Tianshan Mountains, which was closely related to sharp glacial retreats. The increases in glacier and snow meltwater led to an increase in runoff in the three typical river basins, especially that of the Aksu River (0.4108 m3/a). The decreasing and thinning of areas, and increasing equilibrium line altitude (ELV) of glaciers have been the major causes for the decrease in runoff in the three river basins since the mid-1990s. Therefore, the results reveal the mechanisms causing the impacts of glaciers and snow reduction in mountains on regional water resources under climate change, and provide a reference for water resources management in the mountainous river basins.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2016JC012089", "year": 2016, "title": "The phenology of\n A\n rctic\n O\n cean surface warming", "abstract": "In this work, we explore the seasonal relationships (i.e., the phenology) between sea ice retreat, sea surface temperature (SST), and atmospheric heat fluxes in the Pacific Sector of the Arctic Ocean, using satellite and reanalysis data. We find that where ice retreats early in most years, maximum summertime SSTs are usually warmer, relative to areas with later retreat. For any particular year, we find that anomalously early ice retreat generally leads to anomalously warm SSTs. However, this relationship is weak in the Chukchi Sea, where ocean advection plays a large role. It is also weak where retreat in a particular year happens earlier than usual, but still relatively late in the season, primarily because atmospheric heat fluxes are weak at that time. This result helps to explain the very different ocean warming responses found in two recent years with extreme ice retreat, 2007 and 2012. We also find that the timing of ice retreat impacts the date of maximum SST, owing to a change in the ocean surface buoyancy and momentum forcing that occurs in early August that we term the Late Summer Transition (LST). After the LST, enhanced mixing of the upper ocean leads to cooling of the ocean surface even while atmospheric heat fluxes are still weakly downward. Our results indicate that in the near-term, earlier ice retreat is likely to cause enhanced ocean surface warming in much of the Arctic Ocean, although not where ice retreat still occurs late in the season.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2016JF003971", "year": 2016, "title": "Tidally induced variations in vertical and horizontal motion on Rutford Ice Stream, West Antarctica, inferred from remotely sensed observations", "abstract": "To better understand the influence of stress changes over floating ice shelves on grounded ice streams, we develop a Bayesian method for inferring time-dependent 3-D surface velocity fields from synthetic aperture radar (SAR) and optical remote sensing data. Our specific goal is to observe ocean tide-induced variability in vertical ice shelf position and horizontal ice stream flow. Thus, we consider the special case where observed surface displacement at a given location can be defined by a 3-D secular velocity vector, a family of 3-D sinusoidal functions, and a correction to the digital elevation model used to process the SAR data. Using nearly 9 months of SAR data collected from multiple satellite viewing geometries with the COSMO-SkyMed 4-satellite constellation, we infer the spatiotemporal response of Rutford Ice Stream, West Antarctica, to ocean tidal forcing. Consistent with expected tidal uplift, inferred vertical motion over the ice shelf is dominated by semidiurnal and diurnal tidal constituents. Horizontal ice flow variability, on the other hand, occurs primarily at the fortnightly spring-neap tidal period (Msf). We propose that periodic grounding of the ice shelf is the primary mechanism for translating vertical tidal motion into horizontal flow variability, causing ice flow to accelerate first and most strongly over the ice shelf. Flow variations then propagate through the grounded ice stream at a mean rate of \u223c29 km/d and decay quasi-linearly with distance over \u223c85 km upstream of the grounding zone.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-3619-2022", "year": 2022, "title": "Evaluation of six geothermal heat flux maps for the Antarctic LambertAmery glacial system", "abstract": "Abstract. Basal thermal conditions play an important role in ice sheet dynamics, and they are sensitive to geothermal heat flux (GHF). Here we estimate the basal thermal conditions, including basal temperature, basal melt rate, and friction heat underneath the LambertAmery Glacier system in eastern Antarctica, using a combination of a forward model and an inversion from a 3D ice flow model. We assess the sensitivity and uncertainty of basal thermal conditions using six different GHF maps. We evaluate the modelled results using all observed subglacial lakes. The different GHF maps lead to large differences in simulated spatial patterns of temperate basal conditions. The two recent GHF fields inverted from aerial geomagnetic observations have the highest GHF, produce the largest warm-based area, and match the observed distribution of subglacial lakes better than the other GHFs. The modelled basal melt rate reaches 10 to hundreds of millimetres per year locally in the Lambert, Lepekhin, and Kronshtadtskiy glaciers feeding the Amery Ice Shelf and ranges from 05 mm yr1 on the temperate base of the vast inland region.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2016JB013841", "year": 2017, "title": "Uplift and tilting of the Shackleton Range in East Antarctica driven by", "abstract": "Unravelling the long-term evolution of the subglacial landscape of Antarctica is vital for understanding past ice sheet dynamics and stability, particularly in marine-based sectors of the ice sheet. Here we model the evolution of the bedrock topography beneath the Recovery catchment, a sector of the East Antarctic Ice Sheet characterized by fast-flowing ice streams that occupy overdeepened subglacial troughs. We use 3-D flexural models to quantify the effect of erosional unloading and mechanical unloading associated with motion on border faults in driving isostatic bedrock uplift of the Shackleton Range and Theron Mountains, which are flanked by the Recovery, Slessor, and Bailey ice streams. Inverse spectral (free-air admittance) and forward modeling of topography and gravity anomaly data allow us to constrain the effective elastic thickness of the lithosphere (Te) in the Shackleton Range region to 20 km. Our models indicate that glacial erosion, and the associated isostatic rebound, has driven 40-50% of total peak uplift in the Shackleton Range and Theron Mountains. A further 40-50% can be attributed to motion on normal fault systems of inferred Jurassic and Cretaceous age. Our results indicate that the flexural effects of glacial erosion play a key role in mountain uplift along the East Antarctic margin, augmenting previous findings in the Transantarctic Mountains. The results suggest that at 34 Ma, the mountains were lower and the bounding valley floors were close to sea level, which implies that the early ice sheet in this region may have been relatively stable.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1017/JOG.2016.138", "year": 2017, "title": "Asynchronous behavior of outlet glaciers feeding Godth\u00e5bsfjord (Nuup Kangerlua) and the triggering of Narsap Sermia's retreat in SW Greenland", "abstract": "We assess ice loss and velocity changes between 1985 and 2014 of three tidewater and five-land terminating glaciers in Godthabsfjord (Nuup Kangerlua), Greenland. Glacier thinning accounted for 43.8 0.2 km3 of ice loss, equivalent to 0.10 mm eustatic sea-level rise. An additional 3.5 0.3 km3 was lost to the calving retreats of Kangiata Nunaata Sermia (KNS) and Narsap Sermia (NS), two tidewater glaciers that exhibited asynchronous behavior over the study period. KNS has retreated 22 km from its Little Ice Age (LIA) maximum (1761 AD), of which 0.8 km since 1985. KNS has stabilized in shallow water, but seasonally advects a 2 km long floating tongue. In contrast, NS began retreating from its LIA moraine in 200406 (0.6 km), re-stabilized, then retreated 3.3 km during 201014 into an over-deepened basin. Velocities at KNS ranged 56 km a1, while at NS they increased from 1.5 to 5.5 km a1 between 2004 and 2014. We present comprehensive analyses of glacier thinning, runoff, surface mass balance, ocean conditions, submarine melting, bed topography, ice melange and conclude that the 201014 NS retreat was triggered by a combination of factors but primarily by an increase in submarine melting.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S12040-021-01788-8", "year": 2022, "title": "Hydrological mass balance study of Siachen glacier, East Karakoram", "abstract": "The Himalayan cryosphere system is a major source of freshwater supply for the Indian subcontinent. The rivers originating from the Himalaya are strongly influenced by the behaviour of glaciers depending upon the regional climatic variables. Therefore, understanding the mass budget of glaciers is important. In the present study, we discuss the hydrological mass balance of the largest Siachen glacier in the Karakoram range. The computations of runoff and other parameters on such a large glacier are challenging due to data scarcity, difficult accessibility and complex topography of the region. The snowmelt runoff model (SRM) coupled with in-situ and remotely sensed information was used to simulate the glacier runoff for the past three decades (19862018). The accumulation in the form of snowfall and ablation in the form of snowmelt and evaporation were used as inputs for the estimation of hydrological mass balance. The SRM has well estimated the discharge of Siachen glacier with the coefficient of determination (R2) 0.92 and average volume difference (Dv) 4.4% for the validation period. The study revealed that the Siachen glacier experienced few marginally mass gain episodes before 2000 but after that, a rapid and continuous mass loss has been observed. The average mass balance during the past three decades was found to be 0.11 0.24 m w.e./year. This suggests that glaciers of East Karakoram have started losing mass; still, it is not as significant as generally observed in other parts of the Hindu Kush Himalaya.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.JHAZMAT.2021.125971", "year": 2021, "title": "Importance of seasonal sea ice in the western Arctic ocean to the Arctic and global microplastic budgets", "abstract": "Arctic sea ice entraps microplastics (MP) from seawater and atmosphere and is recognized as sink and transport vector of MPs. However, ice-trapped fraction in the global MP budget, contribution of atmospheric input, and linkage among Arctic basins remain unclear. To assess them, we investigated the number- and mass-based data separated by size and shape geometry for MPs in sea ice, snow, and melt pond water from the western Arctic Ocean (WAO). A significant dependency of MP data on measured cutoff size and geometry was found. For the same size range and geometry, sea ice MPs in WAO ((11.4 9.12) 103 N m-3 for 100 m) were within comparable levels with those in other Arctic basins, but showed closer similarity in polymer and shape compositions between WAO and Arctic Central Basin, indicating the strong linkage of the two basins by the Transpolar Drift. Our budgeting shows that a significant amount of plastic particles ((3.4 2.6) 1016 N; 280 701 kilotons), which are missed from the global inventory, is trapped in WAO seasonal sea ice, with ", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1109/TGRS.2020.3043954", "year": 2022, "title": "Greenland Ice Sheet subsurface temperature estimation using ultrawideband microwave radiometry", "abstract": "Ice sheet subsurface temperature is important for understanding glacier dynamics, yet existing methods to obtain the temperature of the ice sheet column are limited to in situ sources at present. The ultrawideband software-defined microwave radiometer (UWBRAD) has been developed to investigate the remote sensing of ice sheet internal temperatures. UWBRAD measures brightness temperature spectra from 0.5 to 2 GHz using 12 subchannels and employs a sophisticated algorithm for detection and mitigation of radio frequency interference (RFI). The instrument was deployed during a flight over northwestern Greenland in September 2017 and acquired the first wideband low-frequency brightness temperature spectra over the ice sheet and coastal regions. The results reveal strong spatial and spectral variations that correlate well with internal ice sheet temperature information. In this article, the section of the flight path ranging from the Camp Century to NEEM to NGRIP boreholes is used for subsurface temperature estimation. A partially coherent forward model is applied along with a Robin model for the temperature profile and a two-scale model of ice sheet density variations to describe measured brightness temperatures. Using this model, vertical temperature profiles are retrieved along the flight path using a sequential Bayesian estimator; borehole measurements at the three campsites are used to obtain Bayesian priors. The retrieved temperature profiles show reasonable behaviors and demonstrate the potential of ultrawideband microwave radiometry for remotely sensing internal ice sheet temperatures.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1038/S41467-022-33231-X", "year": 2022, "title": "The unquantified mass loss of Northern Hemisphere marine-terminating glaciers from 20002020", "abstract": "In the Northern Hemisphere, ~1500 glaciers, accounting for 28% of glacierized area outside the Greenland Ice Sheet, terminate in the ocean. Glacier mass loss at their ice-ocean interface, known as frontal ablation, has not yet been comprehensively quantified. Here, we estimate decadal frontal ablation from measurements of ice discharge and terminus position change from 2000 to 2020. We bias-correct and cross-validate estimates and uncertainties using independent sources. Frontal ablation of marine-terminating glaciers contributed an average of 44.47 6.23 Gt a1 of ice to the ocean from 2000 to 2010, and 51.98 4.62 Gt a1 from 2010 to 2020. Ice discharge from 2000 to 2020 was equivalent to 2.10 0.22 mm of sea-level rise and comprised approximately 79% of frontal ablation, with the remainder from terminus retreat. Near-coastal areas most impacted include Austfonna, Svalbard, and central Severnaya Zemlya, the Russian Arctic, and a few Alaskan fjords.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S13131-017-0992-4", "year": 2017, "title": "Arctic sea ice volume export through the Fram Strait from combined satellite and model data: 19792012", "abstract": "By combing satellite-derived ice motion and concentration with ice thickness fields from a popular model PIOMAS we obtain the estimates of ice volume flux passing the Fram Strait over the 19792012 period. Since current satellite and field observations for sea ice thickness are limited in time and space, the use of PIOMAS is expected to fill the gap by providing temporally continued ice thickness fields. Calculated monthly volume flux exhibits a prominent annual cycle with the peak record in March (roughly 145 km3/month) and the trough in August (10 km3/month). Annual ice volume flux (1 132 km3) is primarily attributable to winter (October through May) outflow (approximately 92%). Uncertainty in annual ice volume export is estimated to be 55 km3 (or 5.7%). Our results also verified the extremely large volume flux appearing between late 1980s and mid- 1990s. Nevertheless, no clear trend was found in our volume flux results. Ice motion is the primary factor in the determination of behavior of volume flux. Ice thickness presented a general decline trend may partly enhance or weaken the volume flux trend. Ice concentration exerted the least influences on modulating trends and variability in volume flux. Moreover, the linkage between winter ice volume flux and three established Arctic atmospheric schemes were examined. Compared to NAO, the DA and EOF3 mechanism explains a larger part of variations of ice volume flux across the strait.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-3649-2022", "year": 2022, "title": "High-resolution imaging of supraglacial hydrological features on the Greenland Ice Sheet with NASA's Airborne Topographic Mapper (ATM) instrument suite", "abstract": "Abstract. Seasonal meltwater pools on the surface of the Greenland Ice Sheet (GrIS) during late spring and summer in lakes on the surface and transforms the ice sheet's surface into a wet environment in the ablation zone below the equilibrium line. These supraglacial lakes in topographic lows on the ice surface are connected by a dendritic pattern of meandering streams and channels that together form a hydrological system consisting of supra-, en-, and subglacial components. Here, we use lidar data from NASA's Airborne Topographic Mapper (ATM) instrument suite and high-resolution optical imagery collected as part of Operation IceBridge (OIB) in spring 2019 over the GrIS to develop methods for the study of supraglacial hydrological features. While airborne surveys have a limited temporal and spatial coverage compared to imaging spaceborne sensors, their high footprint density and high-resolution imagery reveal a level of detail that is currently not obtainable from spaceborne measurements. The accuracy and resolution of airborne measurements complement spaceborne measurements, can support calibration and validation of spaceborne methods, and provide information necessary for high-resolution process studies of the supraglacial hydrological system on the GrIS that currently cannot be achieved from spaceborne observations alone.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1017/JOG.2022.59", "year": 2022, "title": "Application of visual stratigraphy from line-scan images to constrain chronology and melt features of a firn core from coastal Antarctica", "abstract": "Abstract\r\n Establishing an accurate chronology is crucial for interpretation of ice core-based climatic records. While high snow accumulation rates characterise coastal Antarctica, thus enabling recovery of highly resolved climatic records, summertime melting at such low-elevation sites offers challenges in establishing a reliable chronological framework through traditional approaches using the seasonality of stable water isotope and ionic proxy records. Here, we assess visual stratigraphy (VS) obtained from line-scan images as a proxy for annual layer counting in firn section (top 50 m) of the IND-36/B9 ice core (dated 19192016 CE) from the Djupranen Ice Rise in central Dronning Maud Land, East Antarctica. We also used these images to obtain melt history for the site and found that traditional thickness-based quantification of melt proportion results in significant overestimations. Since density has dominant control on VS profile over the firn section, we first used circulant single-spectrum analysis to remove the secular trend and then we extracted the seasonal VS signals attributed to dust and sea-salt inclusions. We find that melt layers do not significantly alter the VS records if masked during pre-processing. The agedepth model based on the reconstructed VS profile revealed an excellent match with identified time-markers within an uncertainty of 2 years.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2014PA002764", "year": 2015, "title": "First records of winter sea ice concentration in the southwest Pacific", "abstract": "We use a Generalized Additive Model (GAM) to provide the first winter sea ice concentration record from two cores located within the southwest Pacific sector of the Southern Ocean. To compliment the application of GAM, a time series analysis on satellite records of sea ice concentration data was used to extend the standard 13.25 year time series used for paleoceanography. After comparing GAM sea ice estimates with previously published paleo sea ice data we then focus on a new paleo winter sea ice record for marine sediment core E27-23 (59\u00b037.1'S, 155\u00b014.3'E), allowing us to provide a more comprehensive view of winter sea ice dynamics for the southwest Pacific Ocean. The paleo winter sea ice concentration estimates provide the first suggestion that winter sea ice within the southwestern Pacific might have expanded during the Antarctic Cold Reversal. Throughout the Holocene, core E27-23 documents millennial scale variability in paleo winter sea ice coverage within the southwest Pacific. Holocene winter sea ice expansion may have resulted from the Laurentide Ice Sheet deglaciation, increased intensity of the westerly winds, as well as a northern migration of the Subtropical and/or Sub-Antarctic Fronts. Brief consideration is given to the development of a paleo summer sea ice proxy. We conclude that there is no evidence that summer sea ice ever existed at core sites SO136-111 and E27-23 over the last 220 and 52,000 years, respectively.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/RS14010062", "year": 2021, "title": "Temporal Variability of Surface Reflectance Supersedes Spatial Resolution in Defining Greenlands Bare-Ice Albedo", "abstract": "Ice surface albedo is a primary modulator of melt and runoff, yet our understanding of how reflectance varies over time across the Greenland Ice Sheet remains poor. This is due to a disconnect between point or transect scale albedo sampling and the coarser spatial, spectral and/or temporal resolutions of available satellite products. Here, we present time-series of bare-ice surface reflectance data that span a range of length scales, from the 500 m for Moderate Resolution Imaging Spectrometers MOD10A1 product, to 10 m for Sentinel-2 imagery, 0.1 m spot measurements from ground-based field spectrometry, and 2.5 cm from uncrewed aerial drone imagery. Our results reveal broad similarities in seasonal patterns in bare-ice reflectance, but further analysis identifies short-term dynamics in reflectance distribution that are unique to each dataset. Using these distributions, we demonstrate that areal mean reflectance is the primary control on local ablation rates, and that the spatial distribution of specific ice types and impurities is secondary. Given the rapid changes in mean reflectance observed in the datasets presented, we propose that albedo parameterizations can be improved by (i) quantitative assessment of the representativeness of time-averaged reflectance data products, and, (ii) using temporally-resolved functions to describe the variability in impurity distribution at daily time-scales. We conclude that the regional melt model performance may not be optimally improved by increased spatial resolution and the incorporation of sub-pixel heterogeneity, but instead, should focus on the temporal dynamics of bare-ice albedo.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2015JC010903", "year": 2016, "title": "Sea ice circulation around the Beaufort Gyre: The changing role of wind forcing and the sea ice state", "abstract": "Sea ice drift estimates from feature tracking of satellite passive microwave data are used to investigate seasonal trends and variability in the ice circulation around the Beaufort Gyre, over the multidecadal period 1980-2013. Our results suggest an amplified response of the Beaufort Gyre ice circulation to wind forcing, especially during the late 2000s. We find increasing anticyclonic ice drift across all seasons, with the strongest trend in autumn, associated with increased ice export out of the southern Beaufort Sea (into the Chukchi Sea). A flux gate analysis highlights consistency across a suite of drift products. Despite these seasonal anticyclonic ice drift trends, a significant anticyclonic wind trend occurs in summer only, driven, in-part, by anomalously anticyclonic winds in 2007. Across all seasons, the ice drift curl is more anticyclonic than predicted from a linear relationship to the wind curl in the 2000s, compared to the 1980s/1990s. The strength of this anticyclonic ice drift curl amplification is strongest in autumn and appears to have increased since the 1980s (up to 2010). In spring and summer, the ice drift curl amplification occurs mainly between 2007 and 2010. These results suggest nonlinear ice interaction feedbacks (e.g., a weaker, more mobile sea ice pack), enhanced atmospheric drag, and/or an increased role of the ocean. The results also show a weakening of the anticyclonic wind and ice circulation since 2010.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-14-3487-2020", "year": 2020, "title": "Surface velocity of the Northeast Greenland Ice Stream (NEGIS):", "abstract": "Abstract. The Northeast Greenland Ice Stream (NEGIS) extends around\n600 km upstream from the coast to its onset near the ice divide in interior\nGreenland. Several maps of surface velocity and topography of interior\nGreenland exist, but their accuracy is not well constrained by in situ\nobservations. Here we present the results from a GPS mapping of surface\nvelocity in an area located approximately 150 km from the ice divide near\nthe East Greenland Ice-core Project (EastGRIP) deep-drilling site. A GPS\nstrain net consisting of 63 poles was established and observed over the\nyears 20152019. The strain net covers an area of 35 km by 40 km, including\nboth shear margins. The ice flows with a uniform surface speed of\napproximately 55 m a1 within a central flow band with longitudinal and\ntransverse strain rates on the order of 104 a1 and increasing by\nan order of magnitude in the shear margins. We compare the GPS results to\nthe Arctic Digital Elevation Model and a list of satellite-derived surface\nvelocity products in order to evaluate these products. For each velocity\nproduct, we determine the bias in and precision of the velocity compared to the\nGPS observations, as well as the smoothing of the velocity products needed\nto obtain optimal precision. The best products have a bias and a precision\nof 0.5 m a1. We combine the GPS results with\nsatellite-derived products and show that organized patterns in flow and\ntopography emerge in NEGIS when the surface velocity exceeds\napproximately 55 m a1 and are related to bedrock topography.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.OCEMOD.2021.101872", "year": 2021, "title": "Sensitivity of Arctic sea ice to melt pond processes and atmospheric forcing: A model study", "abstract": "Melt ponds are pools of meltwater forming principally on Arctic sea ice during the melt season. The albedo of melt ponds is a key component of the surface energy balance. For this reason, various melt pond schemes have been developed for climate models. These schemes require assumptions on the physical processes governing melt ponds as well as a knowledge of the atmospheric state, which are not perfectly known. In this study, we investigate the effects of the sources of uncertainty from the prescribed atmospheric surface state, the melt pond scheme definition and the refreezing formulation of melt ponds on the simulated Arctic sea ice and melt pond properties with the NEMO-LIM3 oceansea ice general circulation model. We find that the simulated melt pond state is largely controlled by the freezing point of melt ponds. The representation of melt ponds is in better agreement with observations when using the freezing point of 0.15C compared to the value of 2.00C, in our model set-up. All the simulations feature positive trends in melt pond area fraction over the past decades. However, only 3 out of 8 simulations have significant positive trends in melt pond volume per sea ice area. This suggests an influence of the sea ice state for melt ponds over the last 30 years. Overall, we find that the simulated sea ice state, and in particular sea ice volume, is more affected by changes in the prescribed atmospheric forcing than by changes in the prescribed melt pond scheme or refreezing formulation. Including explicit melt pond schemes in large-scale sea-ice models offer the possibility to improve the representation of the surface energy balance in climate general circulation models. Our results underline that, in parallel to these efforts in model developments, improved estimates of surface atmospheric conditions will be required to achieve more realistic sea ice states.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-15-897-2021", "year": 2021, "title": "The cooling signature of basal crevasses in a hard-bedded region of the Greenland Ice Sheet", "abstract": "Abstract. Temperature sensors installed in a grid of nine full-depth boreholes drilled in the southwestern ablation zone of the Greenland Ice Sheet recorded cooling in discrete sections of ice over time within the lowest third of the ice column in most boreholes. Rates of temperature change outpace cooling expected from vertical conduction alone. Additionally, observed temperature profiles deviate significantly from the site-average thermal profile that is shaped by all thermomechanical processes upstream. These deviations imply recent, localized changes to the basal thermal state in the boreholes. Although numerous heat sources exist to add energy and warm ice as it moves from the central divide towards the margin such as strain heat from internal deformation, latent heat from refreezing meltwater, and the conduction of geothermal heat across the icebedrock interface, identifying heat sinks proves more difficult. After eliminating possible mechanisms that could cause cooling, we find that the observed cooling is a manifestation of previous warming in near-basal ice. Thermal decay after latent heat is released from freezing water in basal crevasses is the most likely mechanism resulting in the transient evolution of temperature and the vertical thermal structure observed at our site. We argue basal crevasses are a viable englacial heat source in the basal ice of Greenland's ablation zone and may have a controlling influence on the temperature structure of the near-basal ice.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.GCA.2018.12.035", "year": 2019, "title": "Unravelling the high-altitude Nansen blue ice field meteorite trap (East Antarctica) and implications for regional palaeo-conditions", "abstract": "Antarctic blue ice zones, the most productive locations for meteorite recovery on Earth, contain old ice that is easily accessible and available in large quantities. However, the mechanisms behind these meteorite traps remain a topic of ongoing debate. Here, we propose an interdisciplinary approach to improve our understanding of a meteorite trap in Dronning Maud Land (East Antarctica) on the Nansen blue ice field meteorite trap (26003100 m above sea level), where more than half of the Asuka meteorites have been collected. Based on 185 surface blue ice samples, one of the largest observed spatial patterns in oxygen isotopic variation to date is found. Relying on meteorites for which the terrestrial ages are determined using 14C and 36Cl, this surface ice is interpreted to date from the Last Interglacial up to the present-day. By combining state-of-the-art satellite derived surface velocities, surface mass balance modelling and ice flow modelling, we estimate that about 7585% of the meteorites found on the ice field were supplied by ice flow after entering the ice sheet in an accumulation area of a few hundred square kilometres located south (upstream) of the ice field. Less than 0.4 new meteorites per year are supplied to the ice field through ice flow, suggesting that the hundreds of meteorites found 25 years after the first visit to this ice field mostly represent meteorites that were previously not found, rather than newly supplied meteorites. By combining these findings, the infall rate of meteorites from space is estimated, which is in line with values from the literature, but situated at the higher end of the range. A comparison of the oxygen isotopic variation of the surface blue ice to that of the European Project for Ice Coring in Antarctica (EPICA), Dronning Maud Land (EDML) ice core (located 750 km to the west, at the same elevation), suggests that the regional changes in topography have been relatively limited since the Last Interglacial, supporting theories of an overall stable East Antarctic Ice Sheet (EAIS) over this time period.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 3, "name": "Cryospheric Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/TC-14-3215-2020", "year": 2020, "title": "Towards understanding the pattern of glacier mass balances in High", "abstract": "Abstract. Glaciers in High Mountain Asia (HMA) provide an important water\nresource for communities downstream, and they are markedly impacted by global\nwarming, yet there is a lack of understanding of the observed glacier mass\nbalances and their spatial variability. In particular, the glaciers in the\nwestern Kunlun Shan and Karakoram (WKSK) ranges show neutral to positive\nmass balances despite global warming. Using models of the regional climate\nand glacier mass balance, we reproduce the observed patterns of glacier mass\nbalance in High Mountain Asia of the last decades within uncertainties. We\nshow that low temperature sensitivities of glaciers and an increase in\nsnowfall, for a large part caused by increases in evapotranspiration from\nirrigated agriculture, result in positive mass balances in the WKSK. The pattern\nof mass balances in High Mountain Asia can thus be understood from the\ncombination of changes in climatic forcing and glacier properties, with an\nimportant role for irrigated agriculture.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.RSE.2018.03.025", "year": 2018, "title": "Quantifying vulnerability of Antarctic ice shelves to hydrofracture using microwave scattering properties", "abstract": "Recent ice shelf disintegrations on the Antarctic Peninsula and subsequent increases in ice sheet mass loss have highlighted the importance of tracking ice shelf stability with respect to surface melt ponding and hydrofracture. In this study, we use active microwave scatterometry in time-series to estimate melt season duration, and winter backscatter levels as a proxy for relative concentration of refrozen ice lenses in Antarctic ice shelf firn. We demonstrate a physical relationship between melt days and firn/ice backscatter using scatterometry and field data from Greenland, and apply the observed relationship to derive and map a vulnerability index for Antarctica's ice shelves. The index reveals that some remaining Antarctic Peninsula ice shelves have already reached a firn state that is vulnerable to hydrofracture. We also show that the progression of an ice shelf towards vulnerability is affected by many factors, such as surface mass balance, internal stresses, and ice shelf geometry.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/ECS2.3977", "year": 2022, "title": "Potential microbial enzyme activity in seasonal snowpack is high and", "abstract": "Microbes in snow and ice ecosystems in polar regions contribute substantially to C, N, and P cycling, but few studies have explored microbial activity in seasonal snow. The purpose of this study was to explore the relative importance of snow microbial processing of C, N, and P compounds in atmospheric deposition and litter and detect elemental limitations of snow microbes in Rocky Mountain conifer forests. Enzyme activity in snow was orders of magnitude greater than activity reported for lentic and lotic waters in similar environments. Proportions of C/P\u2011 and C/N\u2011acquiring enzymes suggest that snow samples were P limited, or C and P co\u2011limited, while lentic and lotic waters were more N limited. As such, microbes in seasonal snow may change the composition of nutrients and carbon, but these processes are vulnerable to changes in atmospheric deposition and snow extent and duration, which could affect nutrient processing across large areas.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2020GL089037", "year": 2020, "title": "Trends in Winter Light Environment Over the Arctic Ocean: A Perspective", "abstract": "The last few decades have seen a decrease in Arctic ice cover, leading to changes in the structure and function of marine ecosystems. Yet sustained long-term observations of the marine environment are difficult to acquire. Harsh environments limit in situ measurements, while low light and high solar angles hinder ocean color observations from satellite. Here we use masks of valid-invalid ocean color pixels to diagnose ocean conditions and find strong positive trends in the Arctic open-water season close to the ice sheet, generally consistent with sea ice products from satellites. The North East Atlantic with no seasonal ice cover shows weaker, but significant trends indicative of decreasing winter cloud cover. Decreases in both sea ice and cloud cover will increase light availability at the sea surface and potentially enhance phytoplankton growth. Our method allows the winter light conditions to be studied at temporal and spatial scales relevant for phytoplankton dynamics.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ESSD-12-1367-2020", "year": 2020, "title": "Greenland Ice Sheet solid ice discharge from 1986 through March 2020", "abstract": "Abstract. We present a 1986 through March 2020 estimate of Greenland Ice Sheet ice discharge. Our data include all discharging ice that flows faster than 100 m yr1 and are generated through an automatic and adaptable method, as opposed to conventional handpicked gates. We position gates near the present-year termini and estimate problematic bed topography (ice thickness) values where necessary. In addition to using annual time-varying ice thickness, our time series uses velocity maps that begin with sparse spatial and temporal coverage and end with near-complete spatial coverage and 12 d updates to velocity. The 2010 through 2019 average ice discharge through the flux gates is 48749 Gt yr1. The 10 % uncertainty stems primarily from uncertain ice bed location (ice thickness). We attribute the 50 Gt yr1 differences among our results and previous studies to our use of updated bed topography from BedMachine v3. Discharge is approximately steady from 1986 to 2000, increases sharply from 2000 to 2005, and then is approximately steady again. However, regional and glacier variability is more pronounced, with recent decreases at most major glaciers and in all but one region offset by increases in the northwest region through 2017 and in the southeast from 2017 through March 2020. As part of the journal's living archive option and our goal to make an operational product, all input data, code, and results from this study will be updated as needed (when new input data are available, as new features are added, or to fix bugs) and made available at https://doi.org/10.22008/promice/data/ice_discharge (Mankoff, 2020a) and at https://github.com/mankoff/ice_discharge (last access: 6 June 2020, Mankoff, 2020e).", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/RS14194730", "year": 2022, "title": "Estimating Regional Snow Line Elevation Using Public Webcam Images", "abstract": "Snow cover is of high relevance for the Earths climate system, and its variability plays a key role in alpine hydrology, ecology, and socioeconomic systems. Measurements obtained by optical satellite remote sensing are an essential source for quantifying snow cover variability from a local to global scale. However, the temporal resolution of such measurements is often affected by persistent cloud coverage, limiting the application of high resolution snow cover mapping. In this study, we derive the regional snow line elevation in an alpine catchment area using public webcams. We compare our results to the snow line information derived from the Moderate-Resolution Imaging Spectroradiometer (MODIS) and Sentinel-2 snow cover products and find our results to be in good agreement therewith. Between October 2017 and the end of June 2018, snow lines derived from webcams lie on average 55.8 m below and 33.7 m above MODIS snow lines using a normalized-difference snow index (NDSI) of 0.4 and 0.1, respectively, and are on average 53.1 m below snow lines derived from Sentinel-2. We further analyze the superior temporal resolution of webcam-based snow cover information and demonstrate its effectiveness in filling temporal gaps in satellite-based measurements caused by cloud cover. Our findings show the ability of webcam-based snow line elevation retrieval to complement and improve satellite-based measurements.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-17-1-2023", "year": 2023, "title": "Weekly to monthly terminus variability of Greenland's marine-terminating outlet glaciers", "abstract": "Abstract. Seasonal terminus-position variability of Greenland's marine-terminating outlet glaciers is superimposed on multidecadal trends of glacier retreat. To characterize this seasonal variability, we manually digitized terminus positions for 219 marine-terminating glaciers in Greenland from January 2015 through December 2021 using Sentinel-1 synthetic aperture radar (SAR) mosaics. We digitized at a monthly frequency for 199 glaciers and at a 6 d frequency for 20 glaciers. We found that nearly 80 % of glacier termini in Greenland vary significantly on a seasonal basis. For these seasonally varying glaciers, on average, seasonal retreat typically begins in mid-May, and seasonal advance generally commences in early October. The timing of the initiation of the retreat period may be related to the timing of the onset of ice-sheet surface melt. The rate of retreat events peaks in late summer and reaches a minimum in late winter and early spring. The median magnitude of terminus-position seasonality, the difference between glacier length at the dates of peak advance and retreat, is about 220 m. We find a stronger correlation between this magnitude and glacier velocity than between magnitude and glacier width. Terminus-position seasonality can influence longer-term glacier dynamics and, consequently, ice-sheet mass balance. This study contributes to our understanding of terminus-position seasonality for individual glaciers and collectively for glaciers around the entire Greenland Ice Sheet.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-259-2022", "year": 2022, "title": "Retrieval and parameterisation of sea-ice bulk density from airborne multi-sensor measurements", "abstract": "Abstract. Knowledge of sea-ice thickness and volume depends on freeboard observations from satellite altimeters and in turn on information of snow mass and sea-ice density required for the freeboard-to-thickness conversion. These parameters, especially sea-ice density, are usually based on climatologies constructed from in situ observations made in the 1980s and earlier while contemporary and representative measurements are lacking. Our aim with this paper is to derive updated sea-ice bulk density estimates suitable for the present Arctic sea-ice cover and a range of ice types to reduce uncertainties in sea-ice thickness remote sensing. Our sea-ice density measurements are based on over 3000 km of high-resolution collocated airborne sea-ice and snow thickness and freeboard measurements in the western Arctic Ocean in 2017 and 2019. Sea-ice bulk density is derived assuming isostatic equilibrium for different ice types. Our results show higher average bulk densities for both first-year ice (FYI) and especially multi-year ice (MYI) compared to previous studies. In addition, we find a small difference between deformed and possibly unconsolidated FYI and younger MYI. We find a negative-exponential relationship between sea-ice bulk density and sea-ice freeboard and apply this parameterisation to one winter of monthly gridded CryoSat-2 sea-ice freeboard data. We discuss the suitability and the impact of the derived FYI and MYI bulk densities for sea-ice thickness retrievals and the uncertainty related to the indirect method of measuring sea-ice bulk density. The results suggest that retrieval algorithms be adapted to changes in sea-ice density and highlight the need of future studies to evaluate the impact of density parameterisation on the full sea-ice thickness data record.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2022JF006599", "year": 2022, "title": "Glacier surface speed variations on the Kenai Peninsula, Alaska, 2014\u20132019", "abstract": "To characterize the spatiotemporal variations of glacier surface speed on the Kenai Peninsula, Alaska (\u223c3,900 km2), we derived 92 surface speed fields between October 2014 and December 2019 using intensity offset tracking on Sentinel-1 data. On average, speeds are 50% greater in spring (March-May) than the annual mean (69 m a\u22121) while winter speeds are close to the annual mean. While marine-terminating glaciers have their maximum speed near the terminus, both land- and lake-terminating glaciers flow fastest around the median glacier elevation. On average, the lake-terminating and tidewater glaciers flow 1.7 and 2.3 times faster than the land-terminating glaciers, respectively. Monthly variations over the 5-year period are strikingly synchronous regardless of terminus type suggesting that regional-scale meteorological drivers govern the temporal variability. Mean annual speeds fluctuate roughly \u00b110% of the period mean without an apparent trend. At lake-terminating Bear Glacier, a short-term tripling in ice speed in fall 2019 over the area below an ice-dammed lake coincides with an observed glacier lake outburst flood (GLOF). An earlier GLOF caused a persistent breach of the beach barrier between the proglacial lake and ocean which likely led to overall speed-up of the lower glacier part throughout 2019. A significant speedup was also observed at the lower part of the lake-terminating Ellsworth Glacier and attributed to rapid glacier retreat and lake expansion, probably further amplified by the terminus area becoming buoyant and a large tabular iceberg breaking off. Our results highlight the impact of GLOFs and proglacial characteristics in spatial and temporal glacier speed variations.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2015JD023712", "year": 2015, "title": "Atmospheric conditions in the central Arctic Ocean through the melt seasons of 2012 and 2013: Impact on surface conditions and solar energy deposition into the ice-ocean system", "abstract": "Spectral Radiation Buoys and ice mass balance buoys were deployed on first-year ice near the North Pole in April 2012 and 2013, collecting in-band (350-800 nm) solar radiation and ice and snow mass balance data over the complete summer melt seasons. With complementary European ERA-Interim reanalysis, National Centers for Environmental Prediction (NCEP) Climate forecast system version 2 (CFSv2) analysis and satellite passive microwave data, we examine the evolution of atmospheric and surface melt conditions in the two differing melt seasons. Prevailing atmospheric conditions contributed to a longer and more continuous melt season in summer 2012 than in 2013, which was corroborated by in situ observations. ERA-Interim reanalysis data showed that longwave radiation likely played a key role in delaying the snowmelt onset in 2013. The earlier melt onset in 2012 reduced the albedo, providing a positive ice-albedo feedback at a time when solar insolation was high. Due to earlier melt onset and later freeze-up in 2012, more solar heat was deposited into the ice-ocean system than in 2013. Summer 2013 was characterized by later melt onset, intermittent freezing events and an earlier fall freeze-up, resulting in considerably fewer effective days of surface melt and a higher average albedo. Calculations for idealized seasonal albedo evolution show that moving the melt onset just 1 week earlier in mid-June increases the total absorbed solar radiation by nearly 14% for the summer season. Therefore, the earlier melt onset may have been one of the most important factors driving the more dramatic melt season in 2012 than 2013, though atmospheric circulation patterns, e.g., cyclone in early August 2012, likely contributed as well.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-12-2821-2018", "year": 2018, "title": "Persistent tracers of historic ice flow in glacial stratigraphy near Kamb Ice Stream, West Antarctica", "abstract": "Abstract. Variations in properties controlling ice flow (e.g., topography, accumulation\nrate, basal friction) are recorded by structures in glacial stratigraphy.\nWhen anomalies that disturb the stratigraphy are fixed in space, the\nstructures they produce advect away from the source and can be used to trace\nflow pathways and reconstruct ice-flow patterns of the past. Here we provide\nan example of one of these persistent tracers: a prominent unconformity in\nthe glacial layering that originates at Mt. Resnik, part of a subglacial\nvolcanic complex near Kamb Ice Stream in central West Antarctica. The\nunconformity records a change in the regional thinning behavior seemingly\ncoincident (3440117 a) with stabilization of grounding-line\nretreat in the Ross Sea Embayment. We argue that this feature records both\nthe flow and thinning history far upstream of the Ross Sea grounding line,\nindicating a limited influence of observed ice-stream stagnation cycles on\nlarge-scale ice-sheet routing over the last 5700 years.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2022GL100082", "year": 2022, "title": "How Well do Global Snow Products Characterize Snow Storage in High Mountain Asia?", "abstract": "Accurate characterization of peak snow water storage in High Mountain Asia (HMA) is essential for assessing the water supply to over 1 billion downstream residents. Currently, such characterization still relies on modeling due to measurement scarcity. Here, eight global snow products were examined over HMA using a newly developed High Mountain Asia Snow Reanalysis (HMASR) data set as a reference. The focus of intercomparison was on peak annual snow storage, the first-order determinant of warm-season water availability in snow-dominated basins. Across eight products the climatological peak storage over HMA was found to be 161 \u00b1 102 km3 with an average 33% underestimation relative to HMASR. The inter-product variability in cumulative snowfall (335 \u00b1 148 km3) explains the majority (>80%) of peak snow storage uncertainty, while significant accumulation-season snowfall loss to ablation (51% \u00b1 9%) also reveals the critical role of ablation processes on peak snow storage.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-3123-2022", "year": 2022, "title": "Surge dynamics of Shisper Glacier revealed by time-series correlation of optical satellite images and their utility to substantiate a generalized sliding law", "abstract": "Understanding fast ice flow is key to assessing the future of glaciers. Fast ice flow is controlled by sliding at the bed, yet that sliding is poorly understood. A growing number of studies show the relationship between sliding and basal shear stress transitions from an initially rate-strengthening behavior to a rate-independent or rate-weakening behavior. Studies that have tested a glacier sliding law with data remain rare. Surging glaciers, as we show in this study, can be used as a natural laboratory to inform sliding laws because a single glacier shows extreme velocity variations at a subannual timescale. The present study has two main goals: (1) we introduce a new workflow to produce velocity maps with a high spatiotemporal resolution from remote-sensing data, combining Sentinel-2 (S2) and Landsat 8 (L8) and using the results to describe the recent surge of Shisper Glacier, and (2) we present a generalized sliding law and substantiate the sliding-law behavior using the remote sensing dataset. The quality and spatiotemporal resolution of the velocity time series allow us to identify a gradual amplification of spring speed-up velocities in the 2 years leading up to the surge that started in November 2017. We also find that surface velocity patterns during the surge can be decomposed into three main phases, and each phase appears to be associated with hydraulic changes. Using this dataset, we are able to highlight the rate-independent and rate-weakening relationships between resistive stress and sliding during the surge. We then discuss the importance of the generalized sliding relationship to reconcile observations of fast ice flow, and in particular, different surge behaviors. The approach used in this study remains qualitative, but if coupled with better bed-elevation data and numerical modeling could lead to the widespread quantification of sliding-law parameters.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/RS12223793", "year": 2020, "title": "Dark Glacier Surface of Greenland's Largest Floating Tongue Governed by", "abstract": "Surface melt, driven by atmospheric temperatures and albedo, is a strong contribution of mass loss of the Greenland Ice Sheet. In the past, black carbon, algae and other light-absorbing impurities were suggested to govern albedo in Greenlands ablation zone. Here we combine optical (MODIS/Sentinel-2) and radar (Sentinel-1) remote sensing data with airborne radar and laser scanner data, and engage firn modelling to identify the governing factors leading to dark glacier surfaces in Northeast Greenland. After the drainage of supraglacial lakes, the former lake ground is a clean surface represented by a high reflectance in Sentinel-2 data and aerial photography. These bright spots move with the ice flow and darken by more than 20% over only two years. In contrast, sites further inland do not exhibit this effect. This finding suggests that local deposition of dust, rather than black carbon or cryoconite formation, is the governing factor of albedo of fast-moving outlet glaciers. This is in agreement with a previous field study in the area which finds the mineralogical composition and grain size of the dust comparable with that of the surrounding soils.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-10-597-2016", "year": 2016, "title": "Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbr\u00e6", "abstract": "Abstract. Observations over the past 2 decades show substantial ice loss associated with the speed-up of marine-terminating glaciers in Greenland. Here we use a regional three-dimensional outlet glacier model to simulate the behaviour of Jakobshavn Isbr (JI) located in western Greenland. Our approach is to model and understand the recent behaviour of JI with a physical process-based model. Using atmospheric forcing and an ocean parametrization we tune our model to reproduce observed frontal changes of JI during 19902014. In our simulations, most of the JI retreat during 19902014 is driven by the ocean parametrization used and the glacier's subsequent response, which is largely governed by bed geometry. In general, the study shows significant progress in modelling the temporal variability of the flow at JI. Our results suggest that the overall variability in modelled horizontal velocities is a response to variations in terminus position. The model simulates two major accelerations that are consistent with observations of changes in glacier terminus. The first event occurred in 1998 and was triggered by a retreat of the front and moderate thinning of JI prior to 1998. The second event, which started in 2003 and peaked in the summer 2004, was triggered by the final break-up of the floating tongue. This break-up reduced the buttressing at the JI terminus that resulted in further thinning. As the terminus retreated over a reverse bed slope into deeper water, sustained high velocities over the last decade have been observed at JI. Our model provides evidence that the 1998 and 2003 flow accelerations are most likely initiated by the ocean parametrization used but JI's subsequent dynamic response was governed by its own bed geometry. We are unable to reproduce the observed 20102012 terminus retreat in our simulations. We attribute this limitation to either inaccuracies in basal topography or to misrepresentations of the climatic forcings that were applied. Nevertheless, the model is able to simulate the previously observed increase in mass loss through 2014.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2022GL100629", "year": 2022, "title": "Ice Shelf Basal Melt Rates in the Amundsen Sea at the End of the 21st Century", "abstract": "Antarctic Ice Sheet projections show the highest sensitivity to increased basal melting in the Amundsen Sea. However, little is known about the processes that control future increase in melt rates. We build an ensemble of three ocean-sea-ice-ice-shelf simulations for both the recent decades and the late 21st century, constrained by regional atmosphere simulations and the multi-model mean climate change of the fifth Climate Model Intercomparison Project under the RCP8.5 scenario. The ice-shelf melt rates are typically multiplied by 1.4-2.2 from present day to future, for a total basal mass loss increased by 346 Gt yr-1 on average. This is equally explained by advection of warmer water from remote locations and regional changes in Ekman downwelling and in the ice-shelf melt-induced circulation, while increased iceberg melt plays no significant role. Our simulations suggest that high-end melt projections previously used to constrain recent sea level projections may have been significantly overestimated.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.GEOMORPH.2019.02.015", "year": 2019, "title": "Evolution of debris flow and moraine failure in the Gangotri Glacier region, Garhwal Himalaya: Hydro-geomorphological aspects", "abstract": "A debris flow occurred in the foreland of Gangotri Glacier by its former tributary, Meru (Bamak) Glacier between 16 and 19 July 2017. We investigated the debris flow using pre- and post-event field observations; hydro-meteorological data along with remote sensing assessments to understand the mechanism and evolution of the debris flow. A large volume of sediments (7.9 106 m3 0.1 106 m3) moved from the Meru Bamak and adjoining Neela Taal (4380 m a.s.l) during the debris flow, depositing 6.5 106 m3 0.1 106 m3 of sediments in the frontal region (4050 m a.s.l) of the Gangotri Glacier. This event transported sediments up to 1.5 km downstream, as a debris flow fan-type feature. During the event, ~18% of the sediments were transferred by the meltwater stream. The stream of the Meru Bamak completely dissected and exposed the ice-cored left lateral moraine of the Gangotri Glacier. This event comprehensively reworked the morainic material and entirely changed the morphology of the pro-glacial area. A small pro-glacial lake (area: 5075 m2) is also observed at the snout of Gangotri Glacier because of the blockage by morainic material and sediments. A sharp increase in the concentration of suspended sediments (SSC), reaching 11,370 and 10,605 mg/l on July 18 and 19, respectively was recorded at Bhojwasa (~3 km downstream). Multiple factors such as recession of Gangotri Glacier, degraded ice-cored moraine, loose sediments at the front of the Meru Bamak, and continuous rainfall created favourable conditions for the debris flow. Therefore, geomorphic hazards associated with glacial retreat need to be investigated intensively in the Himalaya especially, in areas where significant glacial retreat is observed, lateral moraines are exposed, and the unstable slopes are occupied by the tributary glaciers.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/CP-15-2031-2019", "year": 2019, "title": "A 120 000-year record of sea ice in the North Atlantic?", "abstract": "Abstract. Although it has been demonstrated that the speed and magnitude of the recent Arctic sea ice decline is unprecedented for the past 1450 years, few records are available to provide a paleoclimate context for Arctic sea ice extent. Bromine enrichment in ice cores has been suggested to indicate the extent of newly formed sea ice areas. Despite the similarities among sea ice indicators and ice core bromine enrichment records, uncertainties still exist regarding the quantitative linkages between bromine reactive chemistry and the first-year sea ice surfaces. Here we present a 120 000-year record of bromine enrichment from the RECAP (REnland ice CAP) ice core, coastal east Greenland, and interpret it as a record of first-year sea ice. We compare it to existing sea ice records from marine cores and tentatively reconstruct past sea ice conditions in the North Atlantic as far north as the Fram Strait (5085 N). Our interpretation implies that during the last deglaciation, the transition from multi-year to first-year sea ice started at 17.5 ka, synchronously with sea ice reductions observed in the eastern Nordic Seas and with the increase in North Atlantic ocean temperature. First-year sea ice reached its maximum at 12.411.8 ka during the Younger Dryas, after which open-water conditions started to dominate, consistent with sea ice records from the eastern Nordic Seas and the North Icelandic shelf. Our results show that over the last 120 000 years, multi-year sea ice extent was greatest during Marine Isotope Stage (MIS) 2 and possibly during MIS 4, with more extended first-year sea ice during MIS 3 and MIS 5. Sea ice extent during the Holocene (MIS 1) has been less than at any time in the last 120 000 years.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1038/S41561-021-00841-X", "year": 2021, "title": "Recent strengthening of snow and ice albedo feedback driven by Antarctic sea-ice loss", "abstract": "The decline of the Arctic cryosphere during recent decades has lowered the regions surface albedo, reducing its ability to reflect solar radiation back to space. It is not clear what role the Antarctic cryosphere plays in this regard, but new remote-sensing-based techniques and datasets have recently opened the possibility to investigate its role. Here, we leverage these to show that the surface albedo reductions from sustained post-2000 losses in Arctic snow and ice cover equate to increasingly positive snow and ice albedo feedback relative to a 19821991 baseline period, with a decadal trend of +0.08 0.04 W m2 decade1 between 1992 and 2015. During the same period, the expansion of the Antarctic sea-ice pack generated a negative feedback, with a decadal trend of 0.06 0.02 W m2 decade1. However, substantial Antarctic sea-ice losses during 20162018 completely reversed the trend, increasing the three-year mean combined Arctic and Antarctic snow and ice albedo feedback to +0.26 0.15 W m2. This reversal highlights the importance of Antarctic sea-ice loss to the global snow and ice albedo feedback. The 19922018 mean feedback is equivalent to approximately 10% of anthropogenic CO2 emissions over the same period; the share may rise markedly should 20162018 snow and ice conditions become common, although increasing long-wave emissions will probably mediate the impact on the total radiative-energy budget.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2021JF006287", "year": 2021, "title": "Controls on water storage and drainage in crevasses on the Greenland Ice Sheet", "abstract": "Surface crevasses on the Greenland Ice Sheet (GrIS) capture nearly half of the seasonal runoff, yet their role in transferring meltwater to the bed has received little attention relative to that of supraglacial lakes and moulins. Here, we present observations of crevasse ponding and investigate controls on their hydrological behavior at a fast-moving, marine-terminating sector of the GrIS. We map surface meltwater, crevasses, and surface-parallel stress across a \u223c2,700 km2 region using satellite data and contemporaneous uncrewed aerial vehicle (UAV) surveys. From 2017 to 2019 an average of 26% of the crevassed area exhibited ponding at locations that remained persistent between years despite rapid advection. We find that the spatial distribution of ponded crevasses does not relate to previously proposed controls on the distribution of supraglacial lakes (elevation and topography) or crevasses (von Mises stress thresholds), suggesting the operation of some other physical control(s). Ponded crevasse fields were preferentially located in regions of compressive surface-parallel mean stress, which we interpret to result from the hydraulic isolation of these systems. This contrasts with unponded crevasse fields, which we suggest are readily able to transport meltwater into the wider supraglacial and englacial network. UAV observations show that ponded crevasses can drain episodically and rapidly, likely through hydrofracture. We therefore propose that the surface stress regime influences a spatially heterogeneous transfer of meltwater through crevasses to the bed of ice sheets, with consequences for processes, such as subglacial drainage and the heating of ice via latent heat release by refreezing meltwater.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ESSD-14-3573-2022", "year": 2022, "title": "Elevation change of the Antarctic Ice Sheet: 1985 to 2020", "abstract": "Abstract. The largest uncertainty in future projections of sea level change comes from the uncertain response of the Antarctic Ice Sheet to the warming oceans and atmosphere. The ice sheet gains roughly 2000 km3 of ice from precipitation each year and loses a similar amount through solid ice discharge into the surrounding oceans. Numerous studies have shown that the ice sheet is currently out of long-term equilibrium, losing mass at an accelerated rate and increasing sea level rise. Projections of sea level change rely on accurate estimates of the contribution of land ice to the contemporary sea level budget. The longest observational record available to study the mass balance of the Earth's ice sheets comes from satellite altimeters. This record, however, consists of multiple satellite missions with different life spans and inconsistent measurement types (radar and laser) of varying quality. To fully utilize these data, measurements from different missions must be cross-calibrated and integrated into a consistent record of change. Here, we present a novel approach for generating such a record that implies improved topography removal, cross-calibration, and normalization of seasonal amplitudes from different mission. We describe in detail the advanced geophysical corrections applied and the processes needed to derive elevation change estimates. We processed the full archive record of satellite altimetry data, providing a seamless record of elevation change for the Antarctic Ice Sheet that spans the period 1985 to 2020. The data are produced and distributed as part of the NASA MEaSUREs ITS_LIVE (Making Earth System Data Records for Use in Research Environments Inter-mission Time Series of Land Ice Velocity and Elevation) project (Nilsson et al., 2021, DOI: https://doi.org/10.5067/L3LSVDZS15ZV).", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/RS14122738", "year": 2022, "title": "Sensing the Nighttime EconomyHousing Imbalance from a Mobile Phone Data Perspective: A Case Study in Shanghai", "abstract": "Sensing the nighttime economyhousing imbalance is of great importance for urban planning and commerce. As an efficient tool of social sensing and human observation, mobile phone data provides an effective way to address this issue. In this paper, an indicator, mobile phone data-based nighttime economyhousing imbalance intensity, is proposed to measure the degree of the nighttime economyhousing imbalance. This indicator can distinguish vitality variations between sleep periods and nighttime activity periods, which are highly related to the nighttime economyhousing imbalance. The spatial pattern of the nighttime economyhousing imbalance was explored, and its association with the built environment was investigated through city-scale geographical regression analysis in Shanghai, China. The results showed that the sub-districts of Shanghai with high-positive-imbalance intensities displayed structures with superimposed rings and striped shapes, and the sub-districts with negative imbalance intensities were distributed around high positive-intensity areas. There were significant linear correlations between imbalance intensity and the built environment. The multiple influences of built environment factors and related mechanisms were explored from a geographical perspective. Our study utilized the social sensing data to provide a more comprehensive understanding of the nighttime economyhousing imbalance. These findings will be useful for fostering the nighttime economy and supporting urban renewal.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/S43247-021-00326-0", "year": 2021, "title": "Strategic Forest Reserves can protect biodiversity in the western United States and mitigate climate change", "abstract": "Forest preservation is crucial for protecting biodiversity and mitigating climate change. Here we assess current forest preservation in the western United States using spatial data and find that beyond the 18.9% (17.5 Mha) currently protected, an additional 11.1% (10.3 Mha) is needed to achieve 30% preservation by 2030 (30 30). To help meet this regional preservation target, we developed a framework that prioritizes forestlands for preservation using spatial metrics of biodiversity and/or carbon within each ecoregion. We show that meeting this preservation target would lead to greater protection of animal and tree species habitat, current carbon stocks, future carbon accumulation, and forests that are important for surface drinking water. The highest priority forestlands are primarily owned by the federal government, though substantial areas are also owned by private entities and state and tribal governments. Establishing Strategic Forest Reserves would help protect biodiversity and carbon for climate adaptation and mitigation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 6, "name": "Ecosystems" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.IJDRR.2022.103338", "year": 2023, "title": "Physics-based simulations of multiple natural hazards for risk-sensitive planning and decision making in expanding urban regions", "abstract": "Rapid urban expansion in many parts of the world is leading to increased exposure to natural hazards, exacerbated by climate change. The use of physics-based models of natural hazards in risk-informed planning and decision-making frameworks may provide an improved understanding of site-specific hazard scenarios, allowing various decision makers to more accurately consider the consequences of their decisions on risks in future development. We present results of physics-based simulations of flood, earthquake, and debris flow scenarios in a virtual urban testbed. The effect of climate change, in terms of increasing rainfall intensity, is also incorporated into some of the considered hazard scenarios. We use our results to highlight the importance of using physics-based models applied to high-resolution urban plans to provide dynamic hazard information at the building level for different development options. Furthermore, our results demonstrate that including building elevations into digital elevation models is crucial for predicting the routing of hazardous flows through future urban landscapes. We show that simulations of multiple, independent hazards can assist with the identification of developing urban regions that are vulnerable to potential multi-hazard events. This information can direct further modelling to provide decision-makers with insights into potential multi-hazard events. Finally, we reflect on how information derived from physics-based hazard models can be effectively used in risk-sensitive planning and decision-making.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCS.2019.101652", "year": 2019, "title": "Spatial distribution and opportunity mapping: Applicability of evidence-based policy implications in Punjab using remote sensing and global products", "abstract": "Evidence-based policy-making generally applies scientifically rigorous methods to arrive at location-based decisions for public service facilities. The provision of equal opportunities is becoming increasingly difficult due to urbanization. Most studies examined the inequality in context with social indicators and few empirical studies focused on the distribution of opportunities in the form of opportunity indices. This study aims to examine the spatial distribution of public facilities in 36 districts of Punjab province, Pakistan. We develop a composite opportunity index from various social indicators retrieved from household surveys. Using global and local Moran's indices, we analyzed the social indicators along three lines, i.e., health, education, and civic facilities. We investigated inequalities in opportunities through its various factors derived from NOAA nighttime light data and other global data sets. Results reveal that the allocation of facilities is clustered in north and north-eastern regions of Punjab while southern areas are having large inequality of opportunities in accessing basic services. The inequalities are driven particularly in terms of poverty, road accessibility, and urban infrastructure depicted through nighttime data, while it is not driven by population. The evidence-based method in this research will help implicate policies through prioritizing resource allocation in terms of space and equal opportunities.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/LAND11050698", "year": 2022, "title": "Identification of Priority Areas for Improving Urban Ecological Carrying Capacity: Based on SupplyDemand Matching of Ecosystem Services", "abstract": "As the most concentrated area of human activities, cities consume many natural resources and discharge a large amount of waste into the natural environment, which has a huge environmental impact. Most of the ecological and environmental problems, such as environmental pollution, global climate change, and loss of biodiversity, are related to urban systems. How to coordinate urban development with the urban ecological carrying capacity is related to the destiny of the city itself, and also to whether its surrounding areas can successfully achieve the goal of high environmental quality and sustainable development. At present, the theory and methods of urban ecological carrying capacity research are relatively new, which has caused problems for policy makers in practical applications. This paper proposes a theoretical framework for urban ecological carrying capacity assessment based on the analysis of ecosystem services supply and demand. Combined with multi-source spatial data and spatial model methods, the supply and demand of ecosystem services were spatially quantified. The capital city of China, Beijing, was the case study area for this research. The spatial differentiation of the supplydemand relationship of ecosystem services is formed. The priority areas for ecological carrying capacity improvement at pixel scale and at the administrative level are obtained, respectively. The results show that the first priority area is concentrated in the center of the urban area, accounting for 31.11% of the total area of Beijing. According to the secondary zone and the specific ecosystem service type, the ecological carrying capacity improvement strategy of different zones is proposed. This study provides a new perspective for investigating urban ecological carrying capacity and for identifying the priority areas for ecological carrying capacity improvement, and helps the policy-makers to design tailored policy actions.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ACP-21-8413-2021", "year": 2021, "title": "Global and regional impacts of land cover changes on isoprene emissions", "abstract": "Abstract. Among the biogenic volatile organic compounds (BVOCs) emitted by plant foliage, isoprene is by far the most important in terms of both global\nemission and atmospheric impact. It is highly reactive in the air, and its degradation favours the generation of ozone (in the presence of\nNOx) and secondary organic aerosols. A critical aspect of BVOC emission modelling is the representation of land use and land\ncover (LULC). The current emission inventories are usually based on land cover maps that are either modelled and dynamic or satellite-based and\nstatic. In this study, we use the state-of-the-art Model of Emissions of Gases and Aerosols from Nature (MEGAN) model coupled with the canopy model MOHYCAN (Model for Hydrocarbon emissions by the CANopy) to generate and evaluate emission inventories\nrelying on satellite-based LULC maps at annual time steps. To this purpose, we first intercompare the distribution and evolution (20012016) of\ntree coverage from three global satellite-based datasets, MODerate resolution Imaging Spectroradiometer (MODIS), ESA Climate Change Initiative Land Cover (ESA CCI-LC), and the Global Forest Watch (GFW), and from\nnational inventories. Substantial differences are found between the datasets; e.g. the global areal coverage of trees ranges from 30 to\n50106 km2, with trends spanning from 0.26 to +0.03 % yr1 between 2001 and 2016. At the national level, the increasing\ntrends in forest cover reported by some national inventories (in particular for the US) are contradicted by all remotely sensed datasets. To a great\nextent, these discrepancies stem from the plurality of definitions of forest used. According to some local censuses, clear cut areas and seedling or\nyoung trees are classified as forest, while satellite-based mappings of trees rely on a minimum height. Three inventories of isoprene emissions are\ngenerated, differing only in their LULC datasets used as input: (i) the static distribution of the stand-alone version of MEGAN, (ii) the\ntime-dependent MODIS land cover dataset, and (iii) the MODIS dataset modified to match the tree cover distribution from the GFW database. The mean\nannual isoprene emissions (350520 Tg yr1) span a wide range due to differences in tree distributions, especially in isoprene-rich\nregions. The impact of LULC changes is a mitigating effect ranging from 0.04 to 0.33 % yr1 on the positive trends\n(0.94 % yr1) mainly driven by temperature and solar radiation. This study highlights the uncertainty in spatial distributions of and\ntemporal variability in isoprene associated with remotely sensed LULC datasets. The interannual variability in the emissions is evaluated against\nspaceborne observations of formaldehyde (HCHO), a major isoprene oxidation product, through simulations using the global chemistry transport model\n(CTM) IMAGESv2. A high correlation (R > 0.8) is found between the observed and simulated interannual variability in HCHO columns in most\nforested regions. The implementation of LULC change has little impact on this correlation due to the dominance of meteorology as a driver of\nshort-term interannual variability. Nevertheless, the simulation accounting for the large tree cover declines of the GFW database over several\nregions, notably Indonesia and Mato Grosso in Brazil, provides the best agreement with the HCHO column trends observed by the Ozone Monitoring Instrument (OMI). Overall, our study\nindicates that the continuous tree cover fields at fine resolution provided by the GFW database are our preferred choice for constraining LULC (in\ncombination with discrete LULC maps such as those of MODIS) in biogenic isoprene emission models.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S40808-020-01002-6", "year": 2021, "title": "Multi-criteria modeling for land suitability evaluation of the urban greenbelts in Iran", "abstract": "In this study, a multi-criteria model was considered for land suitability evaluation (LSE) of the urban greenbelt (UGB) in 25 major cities of Iran. On this basis, the greenbelt suitability index (SI) and the environmental change index (Y) of the urban sprawl were estimated for the present and future periods. The research modeling was constructed based on some global datasets and factors (i.e., elevation, slope, soil, land use, land cover, agriculture, precipitation, river and road networks, and settlement sprawl) to evaluate greenbelt suitability. Spatial modeling revealed the highest greenbelt suitability (with SI values above 0.8) for the hinterlands of eight cities, including Hamadan, Zanjan, Sanandaj, Rasht, Sari, Gorgan, Qazvin, and Kermanshah. Results also revealed the estimated Y values of the urban sprawl between 0.07 and 2.32 for all case studies, relating to a mean sprawl disturbance (X) of 0.27 in the status quo (2018). In the probable future time (2030), the Y values were estimated between 0.68 and 5.89 with a mean sprawl disturbance (X) of 0.73 for all case studies, revealing a large increase in the thresholds of the environmental change index. The increase of the Y values in the future time indicates the necessity of new suitable UGB plans with new regulation and optimum to curb the urban land use degradation during future developments.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.UFUG.2018.12.010", "year": 2019, "title": "Relationships between urban development level and urban vegetation states: A global perspective", "abstract": "Urban development exerts both benign and malignant impacts on urban vegetation. Mixed results have been reported regarding the responses of urban vegetation to urbanization. However, these results are limited by both sample size and location. It is essential to conduct global-scale research in urban areas with various development levels in order to acquire a more comprehensive understanding of the relationship between urban development and vegetation states. Thus, we firstly created an urban development score to quantify the development intensity of 68,651 urban areas across 14 biomes through using nighttime light and population density data. We then classified each urban area into a relative development level according to the score and biome. Based on the urban development scores and levels, we determined the relationship between urban development and vegetation states, as represented by the remote-sensed vegetation index. Findings suggested that four distinct types of relationships exist across biomes, namely positive, convex (positive then negative), non-significant, and negative. The positive corrections were commonly found between urban development and vegetation states especially in less-productive biomes such as deserts and open shrublands. However, the positive correlations diminished and eventually turned negative as urban areas became more developed and/or were located in more productive biomes. Turning points of the relationship between urban development and vegetation states were detected in four biomes that have moderate productivity. Completely negative relationships were only found in highly productive tropical and temperate biomes. The results of this study call for a closer examination of the altered urban vegetation states as the result of human engineering.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1186/1750-0680-7-12", "year": 2012, "title": "Total carbon accumulation in a tropical forest landscape", "abstract": "Regrowing tropical forests worldwide sequester important amounts of carbon and restore part of the C emissions emitted by deforestation. However, there are large uncertainties concerning the rates of carbon accumulation after the abandonment of agricultural and pasture land. We report here accumulation of total carbon stocks (TCS) in a chronosequence of secondary forests at a mid-elevation landscape (900-1200 m asl) in the Andean mountains of Colombia.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS14020395", "year": 2022, "title": "An Improved Forest Structure Data Set for Europe", "abstract": "Today, European forests face many challenges but also offer opportunities, such as climate change mitigation, provision of renewable resources, energy and other ecosystem services. Large-scale analyses to assess these opportunities are hindered by the lack of a consistent, spatial and accessible forest structure data. This study presents a freely available pan-European forest structure data set. Building on our previous work, we used data from six additional countries and consider now ten key forest stand variables. Harmonized inventory data from 16 European countries were used in combination with remote sensing data and a gap-filling algorithm to produce this consistent and comparable forest structure data set across European forests. We showed how land cover data can be used to scale inventory data to a higher resolution which in turn ensures a consistent data structure across sub-regional, country and European forest assessments. Cross validation and comparison with published country statistics of the Food and Agriculture Organization (FAO) indicate that the chosen methodology is able to produce robust and accurate forest structure data across Europe, even for areas where no inventory data were available.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JENVMAN.2022.115705", "year": 2022, "title": "Superfund cleanup time and community characteristics: A survival analysis", "abstract": "This paper investigates the correlation of socioeconomic characteristics of communities close to Superfund sites with the duration of cleanup using spatial survival analysis with frailty effects. Census-tract-level data is used to achieve a more accurate representation of affected areas. We find evidence of slower cleanup in areas with higher minority population, particularly when controlling for EPA Region. Additionally, sites that are more costly, have high assessed hazards, and have a Community Action Group are associated with longer cleanup times, while sites which are federally owned and have low assessed hazards are associated with shorter cleanup times.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1680/JENER.17.00025", "year": 2018, "title": "Review of the sub-Saharan African small hydropower situation", "abstract": "The significance of renewable energy sources, such as generation of viable output from small hydropower (SHP), has been of great concern with several measures being taken to alleviate the serious shortfall of electricity supply in rural areas of sub-Saharan Africa. SHP can play very important roles in the electrification of rural areas. The potential for SHP is typically found away from the more populous areas and is a very suitable energy source for the purpose of rural electrification. It can be used either as standalone power source or as a hybrid system with other energy sources. Depletion of fossil fuels and inability to meet the rising demand for electricity are among the hindrances to the economic development of sub-Saharan Africa. This paper focuses on SHP situation in sub-Saharan Africa, especially off-the-grid areas where the central grid is inaccessible. There is a need to establish widespread SHP turbines to overcome this situation. This paper draws conclusions on the importance of designing and implementing SHP turbines for sub-Saharan Africa. It also highlights small-scale hydropower as one of the most cost-effective energy technologies to be considered for electrification, and proposes guidelines to help future implementation of this technology in a better way.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1088/1748-9326/11/8/084003", "year": 2016, "title": "Spatially explicit global population scenarios consistent with the Shared Socioeconomic Pathways", "abstract": "The projected size and spatial distribution of the future population are important drivers of global change and key determinants of exposure and vulnerability to hazards. Spatial demographic projections are widely used as inputs to spatial projections of land use, energy use, and emissions, as well as to assessments of the impacts of extreme events, sea level rise, and other climate-related outcomes. To date, however, there are very few global-scale, spatially explicit population projections, and those that do exist are often based on simple scaling or trend extrapolation. Here we present a new set of global, spatially explicit population scenarios that are consistent with the new Shared Socioeconomic Pathways (SSPs) developed to facilitate global change research. We use a parameterized gravity-based downscaling model to produce projections of spatial population change that are quantitatively consistent with national population and urbanization projections for the SSPs and qualitatively consistent with assumptions in the SSP narratives regarding spatial development patterns. We show that the five SSPs lead to substantially different spatial population outcomes at the continental, national, and sub-national scale. In general, grid cell-level outcomes are most influenced by national-level population change, second by urbanization rate, and third by assumptions about the spatial style of development. However, the relative importance of these factors is a function of the magnitude of the projected change in total population and urbanization for each country and across SSPs. We also demonstrate variation in outcomes considering the example of population existing in a low-elevation coastal zone under alternative scenarios.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1111/1365-2745.13513", "year": 2021, "title": "Nitrogen\u2010fixing trees have no net effect on forest growth in the coterminous United States", "abstract": "Nitrogen (N)\u2011fixing trees fulfil a unique and important biogeochemical role in forests through their ability to convert atmospheric N2 gas to plant\u2011available N. Due to their high N fixation rates, it is often assumed that N\u2011fixing trees facilitate neighbouring trees and enhance forest growth. This assumption is supported by some local studies but contradicted by others, leaving the overall effect of N\u2011fixing trees on forest growth unresolved. Here we use the US Forest Service's Forest Inventory and Analysis database to evaluate the effects of N\u2011fixing trees on plot\u2011scale basal area change and individual\u2011scale neighbouring tree demography across the coterminous US. First we discuss the average trends. At the plot and individual scales, N\u2011fixing trees do not affect the relative growth rates of neighbouring trees, but they facilitate recruitment and inhibit survival rates, suggesting that they are drivers of tree turnover in the coterminous US. At the plot scale, N\u2011fixing trees facilitate the basal area change of non\u2011fixing neighbours. In addition to the average trends, there is wide variation in the effect of N\u2011fixing trees on forest growth, ranging from strong facilitation to strong inhibition. This variation does not show a clear geographical pattern, though it does vary with certain local factors. N\u2011fixing trees facilitate forest growth when they are likely to be less competitive: under high N deposition and high soil moisture or when neighbouring trees occupy different niches (e.g. high foliar C:N trees and non\u2011fixing trees). Synthesis. N\u2011fixing trees have highly variable effects on forest growth and neighbour demographics across the coterminous US. This suggests that the effect of N\u2011fixing trees on forest development and carbon storage depends on local factors, which may help reconcile the conflicting results found in previous localized studies on the effect of N\u2011fixing trees on forest growth.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1186/S13021-019-0126-8", "year": 2019, "title": "Evaluating spatial coverage of data on the aboveground biomass in undisturbed forests in the Brazilian Amazon", "abstract": "Brazilian Amazon forests contain a large stock of carbon that could be released into the atmosphere as a result of land use and cover change. To quantify the carbon stocks, Brazil has forest inventory plots from different sources, but they are unstandardized and not always available to the scientific community. Considering the Brazilian Amazon extension, the use of remote sensing, combined with forest inventory plots, is one of the best options to estimate forest aboveground biomass (AGB). Nevertheless, the combination of limited forest inventory data and different remote sensing products has resulted in significant differences in the spatial distribution of AGB estimates. This study evaluates the spatial coverage of AGB data (forest inventory plots, AGB maps and remote sensing products) in undisturbed forests in the Brazilian Amazon. Additionally, we analyze the interconnection between these data and AGB stakeholders producing the information. Specifically, we provide the first benchmark of the existing field plots in terms of their size, frequency, and spatial distribution.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41467-022-32961-2", "year": 2022, "title": "Forest expansion dominates China's land carbon sink since 1980", "abstract": "Carbon budget accounting relies heavily on Food and Agriculture Organization land-use data reported by governments. Here we develop a new land-use and cover-change database for China, finding that differing historical survey methods biased Chinas reported data causing large errors in Food and Agriculture Organization databases. Land ecosystem model simulations driven with the new data reveal a strong carbon sink of 8.9 0.8 Pg carbon from 1980 to 2019 in China, which was not captured in Food and Agriculture Organization data-based estimations due to biased land-use and cover-change signals. The land-use and cover-change in China, characterized by a rapid forest expansion from 1980 to 2019, contributed to nearly 44% of the national terrestrial carbon sink. In contrast, climate changes (22.3%), increasing nitrogen deposition (12.9%), and rising carbon dioxide (8.1%) are less important contributors. This indicates that previous studies have greatly underestimated the impact of land-use and cover-change on the terrestrial carbon balance of China. This study underlines the importance of reliable land-use and cover-change databases in global carbon budget accounting.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1126/SCIENCE.1244693", "year": 2013, "title": "High-Resolution Global Maps of 21st-Century Forest Cover Change", "abstract": "Forests in Flux\r\n \r\n Forests worldwide are in a state of flux, with accelerating losses in some regions and gains in others.\r\n \r\n Hansen\r\n et al.\r\n \r\n (p.\r\n 850\r\n ) examined global Landsat data at a 30-meter spatial resolution to characterize forest extent, loss, and gain from 2000 to 2012. Globally, 2.3 million square kilometers of forest were lost during the 12-year study period and 0.8 million square kilometers of new forest were gained. The tropics exhibited both the greatest losses and the greatest gains (through regrowth and plantation), with losses outstripping gains.\r\n \r\n , \r\n Landsat data reveals details of forest losses and gains across the globe on an annual basis from 2000 to 2012.\r\n , \r\n Quantification of global forest change has been lacking despite the recognized importance of forest ecosystem services. In this study, Earth observation satellite data were used to map global forest loss (2.3 million square kilometers) and gain (0.8 million square kilometers) from 2000 to 2012 at a spatial resolution of 30 meters. The tropics were the only climate domain to exhibit a trend, with forest loss increasing by 2101 square kilometers per year. Brazils well-documented reduction in deforestation was offset by increasing forest loss in Indonesia, Malaysia, Paraguay, Bolivia, Zambia, Angola, and elsewhere. Intensive forestry practiced within subtropical forests resulted in the highest rates of forest change globally. Boreal forest loss due largely to fire and forestry was second to that in the tropics in absolute and proportional terms. These results depict a globally consistent and locally relevant record of forest change.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS12172813", "year": 2020, "title": "Assessing the Influence of Tourism-Driven Activities on Environmental", "abstract": "Tourism is a primary socio-economic factor on many coastal islands. Tourism contributes to the livelihoods of the residents, but also influences natural resources and energy consumption and can become a significant driver of land conversion and environmental change. Understanding the influence of tourist-related activities is vital for sustainable tourism development. We chose Hainan Island in South China as a research area to study the influence of tourist-driven activities on environmental variables (as Land Surface Temperatures (LST) and related ecosystem variables) during the period of 2000 to 2019. In Hainan, the local economy relies heavily on tourism, with an ever-growing influx of tourists each year. We categorised location-based points of interest (POIs) into two classes, non-tourism sites and tourism-related sites, and utilised satellite data from the cloud-based platform Google Earth Engine (GEE) to extract LST and Normalized Difference Vegetation Index (NDVI) data. We analysed the LST variations, NDVI changes and the land use/land cover (LULC) changes and compared the relative difference in LST and NDVI between the tourism-related sites and non-tourism-related sites. The main findings of this study were: (1) The median LST in the tourism-related sites was relatively higher (1.3) than the LST in the non-tourism-related sites for the 20 years. Moreover, every annual mean LST of tourism-related sites was higher than the LST values in non-tourism-related sites, with an average difference of 1.2 C for the 20 years and a maximum difference of 1.7 C. We found higher annual LST anomalies for tourist-related sites compared to non-tourism sites after 2010, which indicated the likely positive differences in LST above the average LST during 20 years for tourism-related sites when compared against the non-tourism related sites, thus highlighting the potential influence of tourism activities on LST. (2) The annual mean NDVI value for tourism-related sites was significantly lower than for non-tourism places every year, with an average NDVI difference of 0.26 between the two sites. (3) The land cover changed significantly: croplands and forests reduced by 3.5% and 2.8% respectively, while the areas covered by orchards and urban areas increased by 2% and 72.3% respectively. These results indicate the influence of the tourism-driven activities includes the relatively high LST, vegetation degradation and land-use conversion particular to urban cover type. The outcome of this work provides a method that combines cloud-based satellite-derived data with location-based POIs data for quantifying the long-term influence of tourism-related activities on sensitive coastal ecosystems. It contributes to designing evidence-driven management plans and policies for the sustainable tourism development in coastal areas.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS14225790", "year": 2022, "title": "Analyzing Satellite-Derived 3D Building Inventories and Quantifying", "abstract": "Earth observation (EO) data can provide large scale, high-resolution, and transferable methodologies to quantify the sprawl and vertical development of cities and are required to inform disaster risk reduction strategies for current and future populations. We synthesize the evolution of Bishkek, Kyrgyzstan, which experiences high seismic hazard, and derive new datasets relevant for seismic risk modeling. First, the urban sprawl of Bishkek (19792021) was quantified using built-up area land cover classifications. Second, a change detection methodology was applied to a declassified KeyHole Hexagon (KH-9) and Sentinel-2 satellite image to detect areas of redevelopment within Bishkek. Finally, vertical development was quantified using multi-temporal high-resolution stereo and tri-stereo satellite imagery, which were used in a deep learning workflow to extract buildings footprints and assign building heights. Our results revealed urban growth of 139 km2 (92%) and redevelopment of ~26% (59 km2) of the city (19792021). The trends of urban growth were not reflected in all the open access global settlement footprint products that were evaluated. Building polygons that were extracted using a deep learning workflow applied to high-resolution tri-stereo (Pleiades) satellite imagery were most accurate (F1 score = 0.70) compared to stereo (WorldView-2) imagery (F1 score = 0.61). Similarly, building heights extracted using a Pleiades-derived digital elevation model were most comparable to independent measurements obtained using ICESat-2 altimetry data and field-measurements (normalized absolute median deviation < 1 m). Across different areas of the city, our analysis suggested rates of building growth in the region of 200010,700 buildings per year, which when combined with a trend of urban growth towards active faults highlights the importance of up-to-date building stock exposure data in areas of seismic hazard. Deep learning methodologies applied to high-resolution imagery are a valuable monitoring tool for building stock, especially where country-level or open-source datasets are lacking or incomplete.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1515/PEPS-2017-0032", "year": 2017, "title": "Land-use change and communal conflicts in Sub-Saharan Africa", "abstract": "This paper addresses the correlation between land-use changes and communal conflicts in Sub-Saharan Africa. In particular, by articulating the analysis on a 0.5 0.5 regular grid, we estimate the probability of a communal conflict event at time t in any given cell i as a function of a set of variables for land-use variations, a spatial and a temporal lag of the dependent variable, a series of climate attributes and time-invariant geo-physical attributes (all measured at cell level), and a set of institutional attributes (measured at country level). The results show that a positive variation in land-use for agricultural and urban purposes significantly increases both the probability and the number of communal conflicts. On the contrary, the impact of increasing pasture land is not so clear, since results supporting the evidence of a negative relation between pasture use and communal conflicts risk are not robust to different model specifications.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/S22249665", "year": 2022, "title": "Evaluation of Terrestrial Water Storage Changes and Major Driving", "abstract": "Quantitative assessment of the terrestrial water storage (TWS) changes and the major driving factors have been hindered by the lack of direct observations in Inner Mongolia, China. In this study, the spatial and temporal changes of TWS and groundwater storage (GWS) in Inner Mongolia during 20032021 were evaluated using the satellite gravity data from the Gravity Recovery and Climate Experiment (GRACE) and the GRACE Follow On combined with data from land surface models. The results indicated that Inner Mongolia has experienced a widespread TWS loss of approximately 1.82 mm/yr from 20032021, with a more severe depletion rate of 4.15 mm/yr for GWS. Meteorological factors were the driving factors for water storage changes in northeastern and western regions. The abundant precipitation increased TWS in northeast regions at 2.36 mm/yr. Anthropogenic activities (agricultural irrigation and coal mining) were the driving factors for water resource decline in the middle and eastern regions (especially in the agropastoral transitional zone), where the decrease rates were 4.09 mm/yr and 3.69 mm/yr, respectively. In addition, the severities of hydrological drought events were identified based on water storage deficits, with average severity values of 17 mm, 18 mm, 24 mm, and 33 mm for the west, middle, east, and northeast regions, respectively. This study established a basic framework for water resource changes in Inner Mongolia and provided a scientific foundation for further water resources investigation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.SRS.2020.100003", "year": 2020, "title": "A novel method to extract urban human settlements by integrating remote sensing and mobile phone locations", "abstract": "Satellite-based human settlement extraction methods have limited practical applications, due to merely studying the difference between human settlements and other land cover/use types in physical attributes (e.g., spectral signature and land surface temperature) instead of considering basic anthropogenic attributes (e.g., human distribution and human activities). To deal with this challenge, we proposed a novel method to accurately extract human settlements by integrating mobile phone locating-request (MPL) data and remotely sensed data. In this study, human settlements for selected cities were mapped at a medium resolution (30 m) by redistributing the MPL data using Landsat Normalized Difference Vegetation Index (NDVI) adjusted weights, with an overall accuracy of above 90.0%. Additionally, by extending the proposed method to the MPL and Moderate Resolution Imaging Spectroradiometer (MODIS) data, a coarse-resolution (250 m) map of human settlements in China was created with an overall accuracy of 95.2%. Compared with the widely used nighttime light based methods, the proposed method could solve the long-existing problems such as data saturation and blooming effects, as well as characterizing human settlements with fine spatial details. Our study provides an alternative approach to human settlement extraction by combining its physical and anthropogenic attributes, and it can be easily adjusted with multi-scale remotely sensed data and applied to human settlement extraction at different scales.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.RSE.2021.112877", "year": 2022, "title": "World Settlement Footprint 3D-A first three-dimensional survey of the global building stock", "abstract": "Settlements, and in particular cities, are at the center of key future challenges related to global change and sustainable development. Widely used indicators to assess the efficiency and sustainability of settlement development are the compactness and density of the built-up area. However, at global scale, a temporally consistent and spatially detailed survey of the distribution and concentration of the building stock meaning the total area and volume of buildings within a defined spatial unit or settlement, commonly referred to as building density does not yet exist. To fill this data and knowledge gap, an approach was developed to map key characteristics of the world's building stock in a so far unprecedented level of spatial detail for every single settlement on our planet. The resulting World Settlement Footprint 3D dataset quantifies the fraction, total area, average height, and total volume of buildings for a measuring grid with 90 m cell size. The World Settlement Footprint 3D is generated using a modified version of the World Settlement Footprint human settlements mask derived from Sentinel-1 and Sentinel-2 satellite imagery at 10 m spatial resolution, in combination with 12 m digital elevation data and radar imagery collected by the TanDEM-X mission. The underlying, automated processing framework includes three basic workflows: one estimating the mean building height based on an analysis of height differences along potential building edges, a second module determining the building fraction and total building area within each 90 m cell, and a third part combining the height information and building area in order to determine the average height and total built-up volume at 90 m gridding. Optionally, a simple 3D building model (level of detail 1) can be generated for regions where data on the building footprints is available. A comprehensive validation campaign based on 3D building models obtained for 19 regions (~86,000 km2) and street-view samples indicating the number of floors for >130,000 individual buildings in 15 additional cities documents that the novel World Settlement Footprint 3D data provides valuable and, for the first time, globally consistent information on key characteristics of the building stock in both, large urban agglomerations as well as small-scale rural settlements. Thus, the new dataset represents a promising baseline dataset for a wide range of previously impossible environmental, socioeconomic, and climatological studies worldwide.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ECOLMODEL.2016.07.016", "year": 2016, "title": "Divergent projections of future land use in the United States arising from different models and scenarios", "abstract": "A variety of land-use and land-cover (LULC) models operating at scales from local to global have been developed in recent years, including a number of models that provide spatially explicit, multi-class LULC projections for the conterminous United States. This diversity of modeling approaches raises the question: how consistent are their projections of future land use? We compared projections from six LULC modeling applications for the United States and assessed quantitative, spatial, and conceptual inconsistencies. Each set of projections provided multiple scenarios covering a period from roughly 2000 to 2050. Given the unique spatial, thematic, and temporal characteristics of each set of projections, individual projections were aggregated to a common set of basic, generalized LULC classes (i.e., cropland, pasture, forest, range, and urban) and summarized at the county level across the conterminous United States. We found very little agreement in projected future LULC trends and patterns among the different models. Variability among scenarios for a given model was generally lower than variability among different models, in terms of both trends in the amounts of basic LULC classes and their projected spatial patterns. Even when different models assessed the same purported scenario, model projections varied substantially. Projections of agricultural trends were often far above the maximum historical amounts, raising concerns about the realism of the projections. Comparisons among models were hindered by major discrepancies in categorical definitions, and suggest a need for standardization of historical LULC data sources. To capture a broader range of uncertainties, ensemble modeling approaches are also recommended. However, the vast inconsistencies among LULC models raise questions about the theoretical and conceptual underpinnings of current modeling approaches. Given the substantial effects that land-use change can have on ecological and societal processes, there is a need for improvement in LULC theory and modeling capabilities to improve acceptance and use of regional- to national-scale LULC projections for the United States and elsewhere.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.APGEOG.2017.12.014", "year": 2018, "title": "Environmental justice and US Forest Service hazardous fuels reduction: A spatial method for impact assessment of federal resource management actions", "abstract": "Natural resource managers of federal lands in the USA are often tasked with various forms of social and economic impact analysis. Federal agencies in the USA also have a mandate to analyze the potential environmental justice consequences of their activities. Relatively little is known about the environmental justice impacts of natural resource management in rural areas. Quantitative environmental justice analyses have so far heavily favored urban populations, in part owing to the difficulty of quantitative analysis of rural U.S. Census data. We developed a spatial method for integrating rural U.S. Census data with natural resource management data to address this gap. The method learns from methodological advances in overcoming the spatial limitations of Census data, but prioritizes a simple, efficient technique that is applicable not only for identifying potential environmental justice problems, but also to a potentially broad spectrum of natural resource management activities and spatial scales. We pilot test the method by analyzing the hazardous fuels reduction activities of two national forests in central Oregon, USA. We find no evidence of systematic environmental justice issues on either forest, but identify local areas that warrant additional investigation.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/S41598-021-03140-Y", "year": 2021, "title": "Comparative quantification of local climate regulation by green and blue urban areas in cities across Europe", "abstract": "Urban growth alters environmental conditions with major consequences for climate regulation and the exposure of population to heat. Nature-based solutions may be used to alleviate the increasing urban climate pressures, but the climate regulation services that these solutions can supply for and across different urban conditions remains understudied. We comparatively investigate the urban ecosystem service realization (considering the ecosystem service supply and demand spatial interactions) of local climate regulation by vegetated (green) and water-covered (blue) areas across 660 European cities. Results show relatively robust power-law relationships with city population density (average R2 of 0.34) of main indicators of ecosystem service realization. Country-wise fitting for city-average indicators strengthens these relationships, in particular for western European cities (average R2 of 0.66). Cross-city results also show strong power-law relationship of effectiveness in ecosystem service realization with socio-economic measures like Human Development Index and GPD per capita, in particular for the area fraction of city parts with high ecosystem service realization (R2 of 0.77). The quantified relationships are useful for comparative understanding of differences in ecosystem services realization between cities and city parts, and quantitative projection of possible change trends under different types of city growth so that relevant measures can be taken to counteract undesirable trends.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.AGWAT.2021.107106", "year": 2021, "title": "Characterization of water use and water balance for the croplands of Kansas using satellite, climate, and irrigation data", "abstract": "Kansas is one of the most productive agricultural states in the United States, where agricultural irrigation is a primary user of underground and surface water. Because of low precipitation and declining groundwater levels in western and central Kansas, sustainable management of irrigation water resources is a critical issue in the agricultural productivity of the state. The objective of this study is to analyze and characterize the water use and water balance in the croplands of Kansas using satellite observations, meteorological data, and in situ irrigation water use records. We used actual evapotranspiration (ETa), precipitation, soil moisture, and irrigation water use to calculate water balance for Kansas in 2015 at scales of counties, climatic divisions, and groundwater management districts (GMD). The Operational Simplified Surface Energy Balance model was implemented to estimate 30-m resolution ETa. Results showed that the seasonal (May September) precipitation, soil water storage change, and ETa are 528 mm, 80 mm, and 555 mm, respectively, on average of all croplands in the state. The annual net irrigation water consumption was 293 mm for irrigated croplands, indicating that irrigation water constitutes an substantial portion of the water supply in the state. The total volumetric irrigation water use was 3.24 km3 for all croplands within five GMDs in western and south-central Kansas, while only 0.38 km3 was outside of GMDs. The multiple regression models of ETa against precipitation and irrigation water use were statistically significant with R2 values of 0.71 and 0.87, respectively, at county and climate division scales. Regression models also indicated a higher rate of ETa response to irrigation water use than that to precipitation. Our study demonstrated the spatial patterns of crop water use and water balance in Kansas, which could provide useful information for management of irrigation agriculture and water resources for the state.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/BG-19-1891-2022", "year": 2022, "title": "Importance of the forest state in estimating biomass losses from tropical forests: combining dynamic forest models and remote sensing", "abstract": "Abstract. Disturbances, such as extreme weather events, fires,\nfloods, and biotic agents, can have strong impacts on the dynamics and\nstructures of tropical forests. In the future, the intensity of disturbances\nwill likely further increase, which may have more serious consequences for\ntropical forests than those we have already observed. Thus, quantifying\naboveground biomass loss of forest stands due to stem mortality (hereafter\nbiomass loss rate) is important for the estimation of the role of tropical\nforests in the global carbon cycle. So far, the long-term impacts of altered\nstem mortality on rates of biomass loss have not been adequately described. This study aims to analyse the consequences of long-term elevated stem\nmortality rates on forest dynamics and biomass loss rate. We applied an\nindividual-based forest model and investigated the impacts of permanently\nincreased stem mortality rates on the growth dynamics of humid, terra firme\nforests in French Guiana. Here, we focused on biomass, leaf area index\n(LAI), forest height, productivity, forest age, quadratic mean stem\ndiameter, and biomass loss rate. Based on the simulation data, we developed\na multiple linear regression model to estimate biomass loss rates of forests\nin different successional states from the various forest attributes. The findings of our simulation study indicated that increased stem mortality\naltered the succession patterns of forests in favour of fast-growing\nspecies, which increased the old-growth forests' gross primary production,\nthough net primary production remained stable. The stem mortality rate had a\nstrong influence on the functional species composition and tree size\ndistribution, which led to lower values in LAI, biomass, and forest height\nat the ecosystem level. We observed a strong influence of a change in stem\nmortality on biomass loss rate. Assuming a doubling of stem mortality rate, the\nbiomass loss rate increased from 3.2 % yr1 to 4.5 % yr1 at\nequilibrium. We also obtained a multidimensional relationship that allowed\nfor the estimation of biomass loss rates from forest height and LAI. Via an\nexample, we applied this relationship to remote sensing data on LAI and\nforest height to map biomass loss rates for French Guiana. We estimated a\ncountrywide mean biomass loss rate of 3.0 % yr1. The approach described here provides a novel methodology for quantifying\nbiomass loss rates, taking the successional state of tropical forests into\naccount. Quantifying biomass loss rates may help to reduce uncertainties in\nthe analysis of the global carbon cycle.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3233/SJI-220020", "year": 2022, "title": "Measuring Sustainable Development Goals in cities, towns and rural areas: The new Degree of Urbanisation1", "abstract": "The UN Sustainable Development Goals include a range of indicators that incorporate measurements for cities and urban and rural areas. Whereas the methodology for the indicators is harmonised, the definition of urban and rural areas were not National definitions of urban and rural areas differ significantly and make them unsuitable for international comparisons. In 2020, the UN Statistical Commission endorsed a harmonised definition of cities, towns and rural areas for international comparison, called the Degree of Urbanisation. This new method based on a population grid allows for a harmonised comparison of urbanisation across the globe. First estimates indicate that national definitions in several African and Asian countries show substantially higher rural population shares as compared to the harmonised definition. By contrast, rural population shares based on national definitions in Europe and the Americas tend to be similar of lower as compared to the harmonised definition. Comparing the population in large cities based on national definitions and the Degree of Urbanisation reveals a high level of agreement.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/NATURE23285", "year": 2017, "title": "Global forest loss disproportionately erodes biodiversity in intact landscapes", "abstract": "Deforestation increases the odds of a species being threatened by extinction, and this effect is disproportionately strong in relatively intact landscapes, suggesting that efforts are needed to protect intact forest landscapes and prevent a new wave of extinctions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41893-022-00947-Z", "year": 2022, "title": "Sea-level rise from land subsidence in major coastal cities", "abstract": "Coastal land can be lost at rapid rates due to relative sea-level rise (RSLR) resulting from local land subsidence. However, the comparative severity of local land subsidence is unknown due to high spatial variabilities and difficulties reconciling observations across localities. Here we provide self-consistent, high spatial resolution relative local land subsidence (RLLS) velocities derived from Interferometric Synthetic Aperture Radar for the 48 largest coastal cities, which represent 20% of the global urban population. We show that cities experiencing the fastest RLLS are concentrated in Asia. RLLS is also more variable across the 48 cities (16.2 to 1.1 mm per year) than the Intergovernmental Panel on Climate Change estimations of vertical land motion (5.2 to 4.9 mm per year). With our standardized method, the identification of relative vulnerabilities to RLLS and comparisons of RSLR effects accounting for RLLS are now possible across cities worldwide. These will better inform sustainable urban planning and future adaptation strategies in coastal cities.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1162/ADEV_A_00095", "year": 2017, "title": "Natural City Growth in the People's Republic of China", "abstract": "This paper analyzes the growth of Metropolitan Statistical Areas in the PRC between 1992 and 2013 by focusing on the night-light radiancea measure of economic activityof connected subcity places that we refer to as a natural city. This paper documents the rapid growth of natural cities in the PRC between 1992 and 2009 that was followed by a slight reduction in the size of some natural cities between 2010 and 2013 in the aftermath of the recent global financial crisis. Institutional factorssuch as the location of places near Special Economic Zones, the ramifications of legal migration from rural to urban areas following reforms to the hukou (household registration) system, and infrastructure accessibilityare found to be important drivers of the integration of peripheral places into natural cities.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1126/SCIADV.1500965", "year": 2016, "title": "Effects of conservation policy on China's forest recovery", "abstract": "Chinas forest cover exhibited a positive trend that was significantly related with the implementation of a national conservation policy.\r\n , \r\n Forest loss is one of the most pervasive land surface transformations on Earth, with drastic effects on global climate, ecosystems, and human well-being. As part of biodiversity conservation and climate change mitigation efforts, many countries, including China, have been implementing large-scale policies to conserve and restore forests. However, little is known about the effectiveness of these policies, and information on Chinas forest dynamics at the national level has mainly relied on official statistics. In response to international calls for improved reliability and transparency of information on biodiversity conservation and climate change mitigation efforts, it is crucial to independently verify government statistics. Furthermore, if forest recovery is verified, it is essential to assess the degree to which this recovery is attributable to policy, within the context of other relevant factors. We assess the dynamics of forest cover in China between 2000 and 2010 and evaluate the effectiveness of one of the largest forest conservation programs in the worldthe Natural Forest Conservation Program (NFCP). Results indicate that forest cover has significantly increased in around 1.6% of Chinas territory and that the areas exhibiting forest gain experienced a combined increase in net primary productivity (ca. 0.9 Tg of carbon). Among the variables evaluated at county level, the NFCP exhibited a significantly positive relation with forest gain, whereas reduction in rural labor showed a negative relationship with both forest loss and gain. Findings such as these have global implications for forest conservation and climate change mitigation efforts.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3389/FEVO.2019.00479", "year": 2019, "title": "Status of road ecology research in Africa: do we understand the impacts of roads, and how to successfully mitigate them?", "abstract": "Across Africa, transport infrastructure, including roads, is being built in over 30 planned development corridors that are likely to have major impacts on remaining natural habitats and associated biodiversity. Linked to this is the projected increase in human population size, which is predicted to grow by 1.3 billion people by 2050. Road ecology is the study of the ecological effects (both positive and negative) of roads and traffic but is perceived to be under-researched in Africa. In this context, we undertook a systematic review of road ecology research in Africa to understand the geographic and taxonomic scope of work undertaken to date, as well as recommendations for reducing the impacts of roads. We discovered 210 road ecology publications from Africa (published between 1954 and 2016), with most publications from the more affluent and politically stable regions (e.g., southern and East Africa). We found more publications than expected, with relevant research concealed within studies whose primary focus was on other topics. Most publications (1) focused on single species, and in particular on mammals (where chimpanzees and forest elephants were most studied); (2) were from southern Africa; and 3) were conducted in the grassland and savannah biome and the tropical and subtropical forest biome. Most publications examined the direct impacts of roads, in particular wildlife-vehicle collisions. Only one-third of the publications provided some form of recommendation for intervention to reduce or mitigate the impacts of roads, based on evidence from the publication. Most recommended interventions related to ecosystem or natural process recreation, as well as site and area stewardship. Gaps and future directions for research include rigorous testing of measures to mitigate the impacts of roads, inclusion of traffic monitoring in studies, understanding the impacts of upgrading roads, and exploring livelihood, economic and moral incentives and education and training as potential interventions for reducing the impacts of roads. Our review has highlighted the need for accelerating the study of the impacts of roads on natural habitats and biodiversity, in light of planned large-scale infrastructure development, and especially the study of appropriate mitigation measures that can be rigorously assessed and implemented before and during construction and upgrading of roads in Africa.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.GLOPLACHA.2018.03.005", "year": 2018, "title": "Decades of urban growth and development on the Asian megadeltas", "abstract": "The current and ongoing expansion of urban areas worldwide represents the largest mass migration in human history. It is well known that the world's coastal zones are associated with large and growing concentrations of population, urban development and economic activity. Among coastal environments, deltas have long been recognized for both benefits and hazards. This is particularly true on the Asian megadeltas, where the majority of the world's deltaic populations reside. Current trends in urban migration, combined with demographic momentum suggest that the already large populations on the Asian megadeltas will continue to grow. In this study, we combine recently released gridded population density (circa 2010) with a newly developed night light change product (1992 to 2012) and a digital elevation model to quantify the spatial distribution of population and development on the nine Asian megadeltas. Bivariate distributions of population as functions of elevation and coastal proximity quantify potential exposure of deltaic populations to flood and coastal hazards. Comparison of these distributions for the Asian megadeltas show very different patterns of habitation with peak population elevations ranging from 2 to 11 m above sea level over a wide range of coastal proximities. Over all nine megadeltas, over 174 million people reside below a peak population elevation of 7 m. Changes in the spatial extent of anthropogenic night light from 1992 to 2012 show widely varying extents and changes of lighted urban development. All of the deltas except the Indus show the greatest increases in night light brightness occurring at elevations <10 m. At global and continental scales, growth of settlements of all sizes takes the form of evolving spatial networks of development. Spatial networks of lighted urban development in Asia show power law scaling properties consistent with other continents, but much higher rates of growth. The three largest networks of development in China all occur on deltas and adjacent lowlands, and are growing faster than the rest of the urban network in China. Since 2000, the Huanghe Delta + North China Plain urban network has surpassed the Japanese urban network in size and may soon connect with the Changjiang Delta + Yangtze River urban network to form the largest conurbation in Asia.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCS.2022.104022", "year": 2022, "title": "Assessing the sustainability of urbanization at the sub-national level: The Ecological Footprint and Biocapacity accounts of the Budapest Metropolitan Region, Hungary", "abstract": "The growing concentration of people and wealth often results in imbalances of resource consumption and carrying capacity, therefore, the sustainability assessment of urbanization can offer an important basis for global sustainable transition. This paper aims to provide an analysis of the environmental sustainability of urbanization in Hungary focusing on the long-term changes of ecological footprint and biocapacity at the sub-national level, with a special attention to the Budapest Metropolitan Region (BMR). During the research a hybrid method considering an input-output model and household consumption data was used for the calculation of regional ecological footprint, whereas biocapacity was measured on the basis of land use data. Findings suggest, that even though the ecological deficit of the country has been gradually decreasing since the early 2000s, due to a shrinking population and increasing biocapacity, the ecological overshoot is still significant in the case of Budapest and its agglomeration (30 fold and 2.4 fold respectively). The unsustainability of the BMR is caused partly by demographic factors (7.6% population growth as opposed to the the 7.7% decrease in the countryside) and partly by rising per capita ecological footprint values (especially in the agglomeration from 2.73 to 2.92 gha/capita), which are not balanced by biocapacity on the supply side. This research concluded that policy makers in ageing societies with a highly centralized urban system like Hungary should launch programmes targeted specifically to primary metropolitan areas to improve environmental efficiency and encourage people to change their consumption behaviour.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.CITIES.2019.102442", "year": 2020, "title": "Assessing the ecological footprint and biocapacity of Portuguese cities: Critical results for environmental awareness and local management", "abstract": "The unsustainable use of our planet's resources needs to be tackled from different angles and multiple levels of governance. As the human population urbanizes, having access to reliable, cross-cutting, quantitative city-level sustainability metrics is key to understanding the environmental impacts of urban dwellers and the role cities can play in the 21st century sustainability challenge. Framing the environmental pillar of urban sustainability with an overarching metric like the Ecological Footprint informs stakeholders and citizens about a city's overall pressure on the biosphere. In Portugal, six cities established a pioneering collaborative project to guide their transition to sustainability and support city governance; this paper presents the results of the first phase of the project. We tracked annual demand for natural resources and ecological services by the city residents and compared it against the carrying capacity of the cities' ecological assets. We then assessed the ability of this new data to increase local environmental awareness and support local public policies in Portugal and elsewhere. Lessons from this study inform the ongoing debate on the Ecological Footprint's usefulness as sustainability metric for cities, and point to specific policy insights for managing key consumption sectors and reaching key targets such as the UN SDGs.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1029/2020JG005947", "year": 2021, "title": "Forest thinning in ponderosa pines increases carbon use efficiency and energy flow from primary producers to primary consumers", "abstract": "A better understanding of carbon use efficiency (CUE) and carbon allocation during disturbance is critical to improve simulations of the global carbon cycle and understanding future climate impacts. Forest thinning of high stem density, high elevation dry western US forests is becoming more common to reduce severe fire danger but there are uncertainties about how forest thinning may impact forest CUE, carbon allocation and energy flow through the food chain. In three, quarter ha stands with similar soils, elevation and climate along a forest thinning gradient near Flagstaff (AZ), we measured total net primary production (NPP of wood, fine root, and leaves), total autotrophic respiration (Ra of wood, rhizosphere, and canopy respiration), gross primary production (GPP = NPP + Ra) and large mammal herbivory (with camera traps and dung counts) over a \u223c2 year period. We found strong seasonality in all carbon cycling variables and herbivory, peaking during the warm, wet monsoon period. Carbon was produced more efficiently in the thinned stands, with carbon use efficiency (CUE = NPP/GPP) of \u223c0.63, versus the unthinned stand with CUE of 0.38. GPP was similar in the two thinned stands (\u223c3.5 Mg C ha\u22121 yr\u22121) but was about 30% greater in the unthinned stands (5.0 Mg C ha\u22121 yr\u22121). Finally, the thinned stand had higher understory NPP, large herbivore consumption and had triple the total energy going into primary consumers. Overall, the thinning, and the return to a more natural prefire suppression forest structure, increased the CUE and energy flow from primary producers to primary consumers.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1038/S41597-021-01052-0", "year": 2021, "title": "Downscaling SSP-consistent global spatial urban land projections from 1/8-degree to 1-km resolution 20002100", "abstract": "Long-term, spatial urban land projections that simultaneously offer global coverage and local-scale empirical accuracy are rare. Recently a set of such projections was produced using data-science-based simulations and the Shared Socioeconomic Pathways (SSPs). These projections update at decadal time intervals from 2000 to 2100 with a spatial resolution of 1/8 degree, while many socio-environmental studies customarily run their analysis and modelling at finer spatial resolutions, e.g. 1-km. Here we develop and validate an algorithm to downscale the 1/8-degree spatial urban land projections to the 1-km resolution. The algorithm uses an iterative process to allocate the decadal amount of urban land expansion originally projected for each 1/8-degree grid to its constituent 1-km grids. The results are a set of global maps showing urban land fractions at the 1-km resolution, updated at decadal intervals from 2000 to 2100, under five different urban land expansion scenarios consistent with the SSPs. The data can support studies of potential interactions between future urbanization and environmental changes across spatial and temporal scales.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S00484-021-02153-6", "year": 2021, "title": "Engineered bioclimatic responses in ancient settlements: a case study", "abstract": "The Mandya district of Karnataka, India, houses a unique Jain settlement constructed about 1000 years ago. Recent excavations by the Archaeological Survey of India (ASI) indicate a high degree of engineering skills among the builders of this settlement. Adapting to heat-stresses in a region where the Monsoons often failed was and is still a matter of concern. Ingenious methods were adopted to modulate bioclimatic responses to maintain thermal comfort indices. The Aretippurians used composite building fabrics which modulated heat transfer to the interiors. Indeed, the thermal transmittances for these composite fabrics were low to moderate for both the temple complexes as well as the dormitories; these were 0.27 Wm1K1 and 0.23 Wm1K1, respectively. A site visit revealed that a unique and engineered micro-climate was also made to prevail on this hilltop settlement housing several hundred Jain settlers. A granite skirted reservoir was indeed the piece-de-resistance promoting hydraulic air-conditioning for eight months of the year around the premises with copious winds blowing over a large and exposed rain-fed reservoir. This fanned chilled air across the open plan temples, courtyards, and lived-in areas. This paper explores bioclimatic responses for around 120 residents to the prevailing indoor settings modulated by an engineered microclimate. This was possible because of the staggered layout, unique building forms, use of mixed building fabric, and carefully chosen glazing ratios which yielded salubrious settings. Clearly, this entailed a complex interplay between the intercepted solar insolation, structure-driven turbulence, and the transfer of heat across the original composite walls within and around the complex, requiring a systematic experimental as well as modelling study. The experimental part of the project involved the calculation of the thermal transmittivity across the walls made up of fired bricks, granite, and limestone, and the theoretical part involved the use of appropriate software to reconstruct air flow and heat distribution across floors, walls, and ceilings to proxy the original flow pattern yielding the comfortable PMV (predicted mean vote) and PET (physiological equivalent temperature) values within these premises. This exercise may well lead to further explorations on indoor comfort adaptations in tropical settings with the use of many edifying vernacular idioms in ancient settlements which prevail even in modern layouts.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/F11060653", "year": 2020, "title": "US national maps attributing forest change: 1986\u20132010", "abstract": "National monitoring of forestlands and the processes causing canopy cover loss, be they abrupt or gradual, partial or stand clearing, temporary (disturbance) or persisting (deforestation), are necessary at fine scales to inform management, science and policy. This study utilizes the Landsat archive and an ensemble of disturbance algorithms to produce maps attributing event type and timing to >258 million ha of contiguous Unites States forested ecosystems (19862010). Nationally, 75.95 million forest ha (759,531 km2) experienced change, with 80.6% attributed to removals, 12.4% to wildfire, 4.7% to stress and 2.2% to conversion. Between regions, the relative amounts and rates of removals, wildfire, stress and conversion varied substantially. The removal class had 82.3% (0.01 S.E.) users and 72.2% (0.02 S.E.) producers accuracy. A survey of available national attribution datasets, from the data users perspective, of scale, relevant processes and ecological depth suggests knowledge gaps remain.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/S41558-022-01544-W", "year": 2022, "title": "Nation-wide mapping of tree-level aboveground carbon stocks in Rwanda", "abstract": "Trees sustain livelihoods and mitigate climate change but a predominance of trees outside forests and limited resources make it difficult for many tropical countries to conduct automated nation-wide inventories. Here, we propose an approach to map the carbon stock of each individual overstory tree at the national scale of Rwanda using aerial imagery from 2008 and deep learning. We show that 72% of the mapped trees are located in farmlands and savannas and 17% in plantations, accounting for 48.6% of the national aboveground carbon stocks. Natural forests cover 11% of the total tree count and 51.4% of the national carbon stocks, with an overall carbon stock uncertainty of 16.9%. The mapping of all trees allows partitioning to any landscapes classification and is urgently needed for effective planning and monitoring of restoration activities as well as for optimization of carbon sequestration, biodiversity and economic benefits of trees.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ISPRSJPRS.2020.01.028", "year": 2020, "title": "A framework for large-scale mapping of human settlement extent from Sentinel-2 images via fully convolutional neural networks", "abstract": "Human settlement extent (HSE) information is a valuable indicator of world-wide urbanization as well as the resulting human pressure on the natural environment. Therefore, mapping HSE is critical for various environmental issues at local, regional, and even global scales. This paper presents a deep-learning-based framework to automatically map HSE from multi-spectral Sentinel-2 data using regionally available geo-products as training labels. A straightforward, simple, yet effective fully convolutional network-based architecture, Sen2HSE, is implemented as an example for semantic segmentation within the framework. The framework is validated against both manually labelled checking points distributed evenly over the test areas, and the OpenStreetMap building layer. The HSE mapping results were extensively compared to several baseline products in order to thoroughly evaluate the effectiveness of the proposed HSE mapping framework. The HSE mapping power is consistently demonstrated over 10 representative areas across the world. We also present one regional-scale and one country-wide HSE mapping example from our framework to show the potential for upscaling. The results of this study contribute to the generalization of the applicability of CNN-based approaches for large-scale urban mapping to cases where no up-to-date and accurate ground truth is available, as well as the subsequent monitor of global urbanization.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.RSE.2018.11.011", "year": 2020, "title": "Monitoring tropical forest degradation using spectral unmixing and Landsat time series analysis", "abstract": "Tropical forest loss currently contributes 5 to 15% of anthropogenic carbon emissions to the atmosphere. The large uncertainty in emissions estimates is a consequence of many factors, including differences in definitions of forests and degradation, as well as estimation methodologies. However, a primary factor driving uncertainty is an inability to properly account for forest degradation. While remote sensing offers the only practical way of monitoring forest disturbances over large areas, and despite recent improvements in data quality and quantity and processing techniques, remote sensing approaches are still limited in their ability to detect forest degradation. In this paper, a system is presented that uses time series of Landsat data and spectral mixture analysis to detect both degradation and deforestation in forested landscapes. The Landsat data are transformed into spectral endmember fractions and are used to calculate the Normalized Degradation Fraction Index (NDFI; Souza et al., 2005). The spectrally unmixed data are used for disturbance monitoring and land cover classification via time series analysis. To assess the performance of the system, maps of deforestation and degradation were used to stratify the study area for collection of sample data to which unbiased estimators were applied to produce accuracy and area estimates of degradation and deforestation from 1990 to 2013. The approach extends previous research in spectral mixture analysis for identifying forest degradation to the temporal domain. The method was applied using the Google Earth Engine and tested in the Brazilian State of Rondonia. Degradation and deforestation were mapped with 88.0% and 93.3% User's Accuracy, and 68.1% and 85.3% Producer's Accuracy. Area estimates of degradation and deforestation were produced with margins of error of 13.9% and 5.3%, respectively, over the 24 year time period. These results indicate that for Rondonia a decreasing trend in deforestation after 2004 corresponds to an increase in degradation during the same time period.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1108/JOCM-01-2021-0006", "year": 2021, "title": "Understanding the relationship among factors influencing rural tourism: a hierarchical approach", "abstract": "Purpose The aim of this paper is to analyze the interrelationship between factors conducive to rural tourism development. This touristic segment has enormous potential but still lacks consistent means and measures to ensure rural tourism's holistic development in India. Design/methodology/approach The study identified 14 factors, of which nine are from the literature review and five are from interaction with the experts, which influence rural tourism development. The research design comprises three segments, i.e. identifying factors from the literature and expert opinion, conducting interviews with the academic experts and managers, and analyzing the responses recorded. Interpretive structural modeling (ISM) technique is used to determine the interlinkage between the factors and develop a hierarchical relationship. Findings The results indicate that infrastructure development, growing environmental conscience, support of local government and community, availability of funds with the government and participation of the private sector are the primary factors channelizing rural tourism development. Also, attitudes of locals to adapt, tourist travel motives, marketing of the destination, destination characteristics and recommendation by others are the major dependent factors identified. The findings broaden the knowledge on suitable channels for rural tourism development and provide vital information for the formulation of flexible strategies for developing rural tourism in India. Originality/value This paper's originality lies in providing information to clarify the relationships between factors conducive to rural tourism development, an area where limited research has been done.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1109/IGARSS47720.2021.9554272", "year": 2021, "title": "Assessing the Causes of Tropical Forest Degradation Using Landsat Time Series: A Case Study in the Brazilian Amazon", "abstract": "Monitoring forest degradation at fine scale over large area is critical from an environmental point of view since it provides crucial information for many ecological applications. We introduce an automatic method based on optical Landsat time series (20002017) to detect and quantify forest disturbances and to identify the causes of forest degradation. The method is based on i) an automatic spectral unmixing to detect forest's disturbances and on ii) landscape metrics and temporal indicators to detect the causes of forest degradation. We applied the approach in the Brazilian Amazon municipality of Paragominas to map forested areas affected by reduced impact logging, conventional logging or illegal logging and fires.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.JHYDROL.2020.125661", "year": 2021, "title": "Estimation of component contributions to total terrestrial water storage change in the Yangtze river basin", "abstract": "Terrestrial water storage (TWS) is a key variable in global and regional hydrological cycles. In this study, the TWS changes in the Yangtze River Basin (YRB) were derived using the Lagrange multiplier method (LMM) from Gravity Recovery and Climate Experiment (GRACE) data. To assess TWS changes from LMM, different GRACE solutions, different hydrological models, and in situ data were used for validation. Results show that TWS changes from LMM in YRB has the best performance with the correlation coefficients of 0.80 and root mean square error of 1.48 cm in comparison with in situ data. The trend of TWS changes over the YRB increased by 10.39 1.27 Gt yr1 during the 20032015 period. Moreover, TWS change is disintegrated into the individual contributions of hydrological components (i.e., glaciers, surface water, soil moisture, and groundwater) from satellite data, hydrologic models, and in situ data. The estimated changes in individual TWS components in the YRB show that (1) the contribution of glaciers, surface water, soil moisture, and groundwater to total TWS changes is 15%, 12%, 25% and 48%, respectively; (2) Geladandong glacier melt from CryoSat-2/ICESat data has a critical effect on TWS changes with a correlation coefficients of 0.51; (3) the Three Gorges Reservoir Impoundment has a minimal effect on surface water changes (mainly lake water storage), but it has a substantial effect on groundwater storage (GWS), (4) the Poyang and Doting Lake water storage changes are mainly caused by climate change, (5) soil moisture storage change is mainly influenced by surface water, (6) human-induced GWS changes accounted for approximately half of the total GWS. The results of this study can provide valuable information for decision-making in water resources management.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1093/AJAE/AAX038", "year": 2017, "title": "Additionality and Forest Conservation Regulation for Residential Development", "abstract": "AbstractWe analyze the potential effects that a unique forest conservation regulation has on residential development, and assess the additionality in forest cover due to this regulation. We combine panel data on forest cover change from satellite imagery and parcellevel modeling on residential development, including residential subdivisions occurring before and after the regulation is adopted. Our results suggest that after adoption, there was a 21% increase in forest cover within subdivisions relative to the amount without the regulation. The heterogeneous effects of this regulation suggest that on average, forest cover increased for parcels with lower levels of existing forest cover. However, parcels with the highest levels of forest cover continue to have significant decreases in forest cover, despite the regulation, thereby resulting in fragmentation in regions with the most intact forest cover.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1177/1098214020962579", "year": 2020, "title": "Application of Remote Sensing for Ex Ante Decision Support and Evaluating Impact", "abstract": "Deforestation is an environmental stressor that dramatically threatens biodiversity while having adverse, deep-rooted, socioeconomic impacts. Interventions to address deforestation require considerable long-term investments; therefore, assessing their impact is crucial. The UN Convention on Biological Diversity encourages establishing protected areas (PAs) as a strategy to conserve biodiversity, secure ecosystem services, support local livelihoods, and reduce climate change impacts. The Global Environment Facility (GEF) has supported the conservation and management of PAs, yet site accessibility and data availability present challenges in assessing PAs using traditional evaluation methods. We present a novel application of satellite Earth observations for evaluating the effectiveness and impact of PAs as a deforestation mitigation strategy. Geospatial analysis and ecological forecasting methodologies provide an efficient way to quantify land cover change, estimate above ground carbon stock, and evaluate ecosystem services provided by the PAs ex ante. We demonstrate the value of a geospatial approach through the evaluation of GEF-supported PAs in Kenya.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1371/JOURNAL.PONE.0240739", "year": 2020, "title": "Seasonal movements of Bronze Age transhumant pastoralists in western Xinjiang", "abstract": "The paper explores seasonal movements of Bronze Age mobile pastoralists in the western Tianshan mountainous region of Xinjiang, China. Fieldwork by a team from the Institute of Archaeology of the Chinese Academy of Social Science (CASS) and the University of Sydney, Australia have identified cyclical land use practices associated with the Andronovo cultural complex. Their pattern of seasonal movements has been reconstructed through ethnographic studies and analysis of modern snow and grass cover. Using this detailed combination of data, the study defines requirements for seasonal pastureswinter, summer and spring/autumnand shows a clear correlation between modern land use and seasonal patterns of movement in the Bronze Age.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3389/FENVS.2021.652024", "year": 2021, "title": "Australian fires 2019\u20132020: Tropospheric and stratospheric pollution throughout the whole fire season", "abstract": "The historically large and severe wildfires in Australia from September 2019 to March 2020 are known to have injected a smoke plume into the stratosphere around New Year, due to pyro-cumulonimbus (pyro-Cb) activity, that was subsequently distributed throughout the Southern Hemisphere (SH). We show with satellite, ground based remote sensing, and\r\n in situ\r\n observations that the fires before New Year, had already a substantial impact on the SH atmosphere, starting as early as September 2019, with subsequent long-range transport of trace gas plumes in the upper-troposphere. Airborne\r\n in situ\r\n measurements above Southern Argentina in November 2019 show elevated CO mixing ratios at an altitude of 11 km and can be traced back using FLEXPART trajectories to the Australian fires in mid-November 2019. Ground based solar-FTS (Fourier Transform Spectroscopy) observations of biomass burning tracers CO, HCN and C\r\n 2\r\n H\r\n 6\r\n at Lauder, South Island, New Zealand show enhanced tropospheric columns already starting in September 2019. In MLS observations averaged over 3060S, enhanced CO mixing ratios compared to previous years become visible in late October 2019 only at and below the 147 hPa pressure level. Peak differences are found with satellite and ground-based observations for all altitude levels in the Southern Hemisphere in January. With still increased aerosol values following the Ulawun eruption in 2019, averaged satellite observations show no clear stratospheric and upper-tropospheric aerosol enhancements from the Australian fires, before the pyro-Cb events at the end of December 2019. However, with the clear enhancement of fire tracers, we suggest the period September to December 2019 (prior to the major pyro-Cb events) should be taken into account in terms of fire pollutant emissions when studying the impact of the Australian fires on the SH atmosphere.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1038/S41467-022-29623-8", "year": 2022, "title": "New seasonal pattern of pollution emerges from changing North American wildfires", "abstract": "Rising emissions from wildfires over recent decades in the Pacific Northwest are known to counteract the reductions in human-produced aerosol pollution over North America. Since amplified Pacific Northwest wildfires are predicted under accelerating climate change, it is essential to understand both local and transported contributions to air pollution in North America. Here, we find corresponding increases for carbon monoxide emitted from the Pacific Northwest wildfires and observe significant impacts on both local and down-wind air pollution. Between 2002 and 2018, the Pacific Northwest atmospheric carbon monoxide abundance increased in August, while other months showed decreasing carbon monoxide, so modifying the seasonal pattern. These seasonal pattern changes extend over large regions of North America, to the Central USA and Northeast North America regions, indicating that transported wildfire pollution could potentially impact the health of millions of people.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ENVSOFT.2019.104555", "year": 2020, "title": "PFHydro: A new watershed-scale model for post-fire runoff simulation", "abstract": "Runoff increases after wildfires that burn vegetation and create a condition of soil-water repellence (SWR). A new post-fire watershed hydrological model, PFHydro, was created to explicitly simulate vegetation interception and SWR effects for four burn severity categories: high, medium, low severity and unburned. The model was applied to simulate post-fire runoff from the Upper Cache Creek Watershed in California, USA. NashSutcliffe modeling efficiency (NSE) was used to assess model performance. The NSE was 0.80 and 0.88 for pre-fire water years (WY) 2000 and 2015, respectively. NSE was 0.88 and 0.93 for WYs 2016 (first year post-fire) and 2017 respectively. The simulated percentage of surface runoff in total runoff of WY 2016 was about six times that of pre-fire WY 2000 and three times that of WY 2015. The modeling results suggest that SWR is an important factor for post-fire runoff generation. The model was successful at simulating SWR behavior.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1111/GCB.15158", "year": 2020, "title": "Wildfire combustion and carbon stocks in the southern Canadian boreal forest: Implications for a warming world", "abstract": "AbstractBoreal wildfires are increasing in intensity, extent, and frequency, potentially intensifying carbon emissions and transitioning the region from a globally significant carbon sink to a source. The productive southern boreal forests of central Canada already experience relatively high frequencies of fire, and as such may serve as an analog of future carbon dynamics for more northern forests. Firecarbon dynamics in southern boreal systems are relatively understudied, with limited investigation into the drivers of prefire carbon stocks or subsequent combustion. As part of NASA's ArcticBoreal Vulnerability Experiment, we sampled 79 stands (47 burned, 32 unburned) throughout central Saskatchewan to characterize above and belowground carbon stocks and combustion rates in relation to historical land use, vegetation characteristics, and geophysical attributes. We found southern boreal forests emitted an average of 3.3 1.1 kg C/m2 from field sites. The emissions from southern boreal stands varied as a function of stand age, fire weather conditions, ecozone, and soil moisture class. Sites affected by historical timber harvesting had greater combustion rates due to faster carbon stock recovery rates than sites recovering from wildfire events, indicating that different boreal forest land use practices can generate divergent carbon legacy effects. We estimate the 2015 fire season in Saskatchewan emitted a total of 36.3 15.0 Tg C, emphasizing the importance of southern boreal fires for regional carbon budgets. Using the southern boreal as an analog, the northern boreal may undergo fundamental shifts in forest structure and carbon dynamics, becoming dominated by stands <70 years old that hold 27 kg C/m2 less than current mature northern boreal stands. Our latitudinal approach reinforces previous studies showing that northern boreal stands are at a high risk of holding less carbon under changing disturbance conditions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-22-419-2022", "year": 2022, "title": "Observed slump of sea land breeze in Brisbane under the effect of aerosols from remote transport during 2019 Australian mega fire events", "abstract": "Abstract. The 2019 Australian mega fires were unprecedented considering their intensity and consistency. There has been much research on the environmental and ecological effects of these mega fires, most of which focused on the effect of huge aerosol loadings and the ecological devastation. Sea land breeze (SLB) is a regional thermodynamic circulation closely related to coastal pollution dispersion, yet few have looked into how it is influenced by different types of aerosols transported from either nearby or remote areas. Mega fires provide an optimal scenario of large aerosol emissions. Near the coastal site of Brisbane Archerfield during January 2020, when mega fires were the strongest, reanalysis data from Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) showed that mega fires did release huge amounts of aerosols, making aerosol optical depth (AOD) of total aerosols, black carbon (BC) and organic carbon (OC) approximately 240 %, 425 % and 630 % of the averages in other non-fire years. Using 20 years' wind observations of hourly time resolution from a global observation network managed by the National Oceanic and Atmospheric Administration (NOAA), we found that the SLB day number during that month was only 4, accounting for 33.3 % of the multi-years' average. The land wind (LW) speed and sea wind (SW) speed also decreased by 22.3 % and 14.8 % compared with their averages respectively. Surprisingly, fire spot and fire radiative power (FRP) analysis showed that heating effects and aerosol emission of the nearby fire spots were not the main causes of the local SLB anomaly, while the remote transport of aerosols from the fire centre was mainly responsible for the decrease of SW, which was partially offset by the heating effect of nearby fire spots and the warming effect of long-range transported BC and CO2. The large-scale cooling effect of aerosols on sea surface temperature (SST) and the burst of BC contributed to the slump of LW. The remote transport of total aerosols was mainly caused by free diffusion, while the large-scale wind field played a secondary role at 500 m. The large-scale wind field played a more important role in aerosol transport at 3 km than at 500 m, especially for the gathered smoke, but free diffusion remained the major contributor. The decrease of SLB speed boosted the local accumulation of aerosols, thus making SLB speed decrease further, forming a positive feedback mechanism.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.RSE.2020.112115", "year": 2021, "title": "A comprehensive characterization of MODIS daily burned area mapping accuracy across fire sizes in tropical savannas", "abstract": "Daily global burned area mapping of Earth from remotely sensed data is of considerable interest and indicates a clear user need, despite well-known accuracy limitations. Many studies report global and regional indicators of spatial and temporal accuracy to evaluate the quality of burned area products, but tend to rely on relatively sparse validation data. In this paper, an extensive validation data set covering 223 million ha over the Brazilian Cerrado for the 2015 fire season is used to thoroughly evaluate how the accuracy of burned area products relying on distinct spectral channels (SWIR+NIR versus NIR) and spatial resolution (250 m, 500 m, and both) depends on fire size. Toward this end, we consider publicly available burned area products MCD64A1 (v006) at 500 m and FireCCI51 at 250 m and use a recently proposed graph-based patch algorithm, which is flexible enough to combine 250500 m bands. The trade-off between spatial resolution and spectral channels for the problem at hand reveals that better spatial resolution (NIR at 250 m) is preferable to a broader range of spectral channels (NIR + SWIR at 500 m) for small burns (<250 ha), but that this relation is not preserved for large burns (>1000 ha). Also, this study shows that combining both spectral indices into a single classifier leads to the most accurate burned area map. The analysis by land cover type indicates that overall accuracy is highest for grasslands and savannas, with grasslands benefiting the most from the use of SWIR bands. Results also indicate that burned areas can be classified with accuracy measured by the Dice Coefficient close to 80% for fire sizes larger than 500 ha, which corresponds to 60% of the total burned area, but accuracy lower than 36% for fire sizes smaller than 250 ha. In particular, our analysis suggests that the validation of burned area products always should be linked to the description of fire size distribution since it is a fundamental driver of accuracy. Results show that MODIS daily burned area mapping at 250500 m spatial resolution can exhibit high temporal accuracy, with almost unbiased estimates and standard deviation close to 1.5 days, indicating an accurate characterization of the spread of large fires.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.18488/JOURNAL.13.2021.102.69.84", "year": 2021, "title": "Seasonal Wildfire Outbreak Trend and its Consequences on Forest Biodiversity and the Environment: A Case Study of Sierra Leone", "abstract": "Sierra Leone is classified as a high wildfire risk country with a weather that support 50% chance of igniting wildfire especially from January to March each year. Wildfire outbreak in Sierra Leone has been having ecological, economic and health impacts on people and the environment over the years. This case study explores Sierra Leones wildfire outbreak trend, distribution, status, causes and consequences on biodiversity & the environment and proposed the way forward in tackling wildfire ignition, prevention and control methods in the near future. The daily active fire data from November 2000 to December 2019 were acquired from NASA MCD14DL product. Centroid vectors of fire events in 1 km by 1 km pixel were counted to give the total number of fire events in different administrative regions. Data was imported into the R Studio, version 4.0.3 from 2000-2019 for visualization and other graphical representation. The results show that the north-west and south-west experiences more wildfire incidence than other regions in Sierra Leone hence affecting the natural ecosystem. January to March was detected as the most wildfire prone months especially in the northern part of Sierra Leone. The results suggest that topography; climatic pattern and vegetation type has been considered a strong factor in influencing wildfire ignition over the years. The study concludes that the outdated 1924 fire prevention and control Act and climate change uncertainties are partially responsible for the frequent wildfire outbreak across Sierra Leone.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-21-18319-2021", "year": 2021, "title": "Formaldehyde evolution in US wildfire plumes during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ)", "abstract": "Abstract. Formaldehyde (HCHO) is one of the most abundant non-methane volatile organic compounds (VOCs) emitted by fires. HCHO also undergoes chemical production and loss as a fire plume ages, and it can be an important oxidant precursor. In this study, we disentangle the processes controlling HCHO by examining its evolution in wildfire plumes sampled by the NASA DC-8 during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ) field campaign. In 9 of the 12 analyzed plumes, dilution-normalized HCHO increases with physical age (range 16 h). The balance of HCHO loss (mainly via photolysis) and production (via OH-initiated VOC oxidation) seems to control the sign and magnitude of this trend. Plume-average OH concentrations, calculated from VOC decays, range from 0.5 ( 0.5) 106 to 5.3 ( 0.7) 106 cm3. The production and loss rates of dilution-normalized HCHO seem to decrease with plume age. Plume-to-plume variability in dilution-normalized secondary HCHO production correlates with OH abundance rather than normalized OH reactivity, suggesting that OH is the main driver of fire-to-fire variability in HCHO secondary production. Analysis suggests an effective HCHO yield of 0.33 ( 0.05) per VOC molecule oxidized for the 12 wildfire plumes. This finding can help connect space-based HCHO observations to the oxidizing capacity of the atmosphere and to VOC emissions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2020GL090707", "year": 2020, "title": "High temporal resolution satellite observations of fire radiative power reveal link between fire behavior and aerosol and gas emissions", "abstract": "Wildfire smoke influences on air quality and atmospheric chemistry have been underscored by the increasing fire prevalence in recent years, and yet, the connection between fire, smoke emissions, and the subsequent transformation of this smoke in the atmosphere remains poorly constrained. Toward improving these linkages, we present a new method for coupling high time-resolution satellite observations of fire radiative power with in situ observations of smoke aerosols and trace gases. We apply this technique to 13 fire plumes comprehensively characterized during the recent FIREX-AQ mission and show that changes in fire radiative power directly translate into changes in conserved smoke tracers (CO2, CO, and black carbon aerosol) observed in the downwind smoke plume. The correlation is particularly strong for CO2 (mean r > 0.9). This method is important for untangling the competing effects of changing fire behavior versus the influence of dilution and atmospheric processing on the downwind evolution of measured smoke properties.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2021GL096814", "year": 2022, "title": "Cloud\u2010to\u2010Ground Lightning and Near\u2010Surface Fire Weather Control Wildfire Occurrence in Arctic Tundra", "abstract": "Wildfire is a dominant disturbance agent in pan-Arctic tundra and can significantly impact terrestrial carbon balance and ecosystem functioning. Interactions between fire and climate change can enhance their impacts on the Arctic. However, the driving mechanisms of tundra fire occurrence remain poorly understood. This study focuses on identifying key environmental factors controlling fire occurrence in Arctic tundra of Alaska. Our random forest models, considering ignition source, fuel, fire weather, and topography, have shown a strong predictive capability with an overall accuracy above 91%. We found cloud-to-ground (CG) lightning to be the dominant driver controlling tundra fire occurrence. Near-surface weather warmer and drier than normal was required to support burning, while fuel composition and topography have modest correlations with fire occurrence. Our results highlight the critical role of CG lightning in driving tundra fires and that incorporating lightning in modeling is essential for fire monitoring, forecasting, and management in the Arctic.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2017JD027927", "year": 2018, "title": "Satellite-Observed Impacts of Wildfires on Regional Atmosphere", "abstract": "Emissions of aerosols and trace gases from wildfires and their direct shortwave radiative forcing (DSRF) at the top of atmosphere were studied using satellite observations from Moderate-Resolution Imaging Spectroradiometer, Atmospheric Infrared Sounder, Clouds and Earth Radiant Energy System on Aqua, and Ozone Monitoring Instrument on Aura. The dominant fuel types of the selected fire cases in the northeast of China (NEC), Siberia (Russia), and California (USA) are cropland, mixed forest, and needle-leaf forest, respectively. For the cropland fire case in NEC, the fire radiative power-based emission coefficients (Ce) of aerosol is 20.51 \u00b1 2.55 g/MJ, half that of the forest fire cases in Siberia (40.01 \u00b1 9.21 g/MJ) and California (45.23 \u00b1 8.81 g/MJ), and the carbon monoxide (CO) Ce (23.94 \u00b1 11.83 g/MJ) was about one third and half that of the forest fire cases in Siberia and California, respectively. However, the NOx (NO2 + NO) Ce (2.76 \u00b1 0.25g MJ-1) of the cropland fire in NEC was nearly 3 times that of those forest fire cases. Ratios of NOx to aerosol, HCHO, and CO in the cropland case in NEC show much higher values than those in the forest fire cases. Despite the differences of the Ce and the composition ratios, the DSRF efficiency of smoke aerosol at the top of atmosphere showed similar values among those fire cases. Our results highlight the large variability of emission rate and relative chemical composition but similar DSRF efficiencies among wildfires, which would provide valuable information for understanding the impact of fire on air quality and climate.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.156303", "year": 2022, "title": "Projections of fire probability and ecosystem vulnerability under 21st century climate across a trans-Andean productivity gradient in Patagonia", "abstract": "Warming trends are altering fire regimes globally, potentially impacting on the long-term persistence of some ecosystems. However, we still lack clear understanding of how climatic stressors will alter fire regimes along productivity gradients. We trained a Random Forests model of fire probabilities across a 5lat 2 long trans-Andean rainfall gradient in northern Patagonia using a 23-year long fire record and biophysical, vegetation, human activity and seasonal fire weather predictors. The final model was projected onto mid- and late 21st century fire weather conditions predicted by an ensemble of GCMs using 4 emission scenarios. We finally assessed the vulnerability of different forest ecosystems by matching predicted fire return intervals with critical forest persistence fire return thresholds developed with landscape simulations. Modern fire activity showed the typical hump-shaped relationship with productivity and a negative distance relationship with human settlements. However, fire probabilities were far more sensitive to current season fire weather than to any other predictor. Sharp responsiveness of fire to the accelerating drier/warmer fire seasons predicted for the remainder of the 21st century in the region led to 2 to 3-fold (RCPs 4.5 and 8.5) and 3 to 8-fold increases in fire probabilities for the mid- and late 21st century, respectively. Contrary to current generalizations of larger impacts of warming on fire activity in fuel-rich ecosystems, our modeling results showed first an increase in predicted fire activity in less productive ecosystems (shrublands and steppes) and a later evenly amplified fire activity-productivity relationship with it shape resembling (at higher fire probabilities) the modern hump-shaped relationship. Despite this apparent homogeneous effect of warming on fire activity, vulnerability to predicted late 21st century shorter fire intervals were higher in most productive ecosystems (subalpine deciduous and evergreen Nothofagus-dominated rainforests) due to a general lack of fire-adapted traits in the dominant trees that compose these forests.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2021GH000546", "year": 2022, "title": "Health Risk Implications of Volatile Organic Compounds in Wildfire Smoke During the 2019 FIREXAQ Campaign and Beyond", "abstract": "Fire Influence on Regional to Global Environments and Air Quality was a NOAA/NASA collaborative campaign conducted during the summer of 2019. The objectives included identifying and quantifying wildfire composition, smoke evolution, and climate and health impacts of wildfires and agricultural fires in the United States. Ground based mobile sampling via sorbent tubes occurred at the Nethker and Williams Flats fires (2019) and Chief Timothy and Whitetail Loop fires (2020) in Idaho and Washington. Air samples were analyzed through thermal desorption-gas chromatography-mass spectrometry for a variety of volatile organic compounds to elucidate both composition and health impacts. Benzene, toluene, ethylbenzene, xylenes, butenes, phenol, isoprene and pinenes were observed in the wildfire smoke, with benzene ranging from 0.04 to 25 ppbv. Health risk was assessed for each fire by determining sub-chronic (wildfire event) and projected chronic inhalation risk exposure from benzene, a carcinogen, as well as other non-carcinogenic compounds including toluene, ethylbenzene, xylenes, and hexane. The cancer risk of benzene from sub-chronic exposure was 1 extra cancer per million people and ranged from 1 to 19 extra cancers per million people for the projected chronic scenarios, compared to a background level of 1 extra cancer per million people. The hazard index of non-carcinogenic compounds was less than one for all scenarios and wildfires sampled, which was considered low risk for non-cancer health events.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1175/JAS-D-20-0131.1", "year": 2020, "title": "Smoke with induced rotation and lofting (SWIRL) in the stratosphere", "abstract": "Abstract The Australian bushfires of 2019/20 produced an unusually large number of pyrocumulonimbus (pyroCb) that injected huge amounts of smoke into the lower stratosphere. The pyroCbs from 29 December 2019 to 4 January 2020 were particularly intense, producing hemispheric-wide aerosol that persisted for months. One plume from this so-called Australian New Year (ANY) event evolved into a stratospheric aerosol mass ~1000 km across and several kilometers thick. This plume initially moved eastward toward South America in January, then reversed course and moved westward passing south of Australia in February and eventually reached South Africa in early March. The peculiar motion was related to the steady rise in plume potential temperature of ~8 K day1 in January and ~6 K day1 in February, due to local heating by smoke absorption of solar radiation. This heating resulted in a vertical temperature anomaly dipole, a positive potential vorticity (PV) anomaly, and anticyclonic circulation. We call this dynamical component of the smoke plume smoke with induced rotation and lofting (SWIRL). This study uses Navy Global Environmental Model (NAVGEM) analyses to detail the SWIRL structure over 2 months. The main diagnostic tool is an anticyclone edge calculation based on the scalar Q diagnostic. This provides the framework for calculating the time evolution of various SWIRL properties: PV anomaly, streamfunction, horizontal size, vertical thickness, flow speed, and tilt. In addition, we examine the temperature anomaly dipole, the SWIRL interaction with the large-scale wind shear, and the ozone anomaly associated with lofting of air from the lower to the middle stratosphere.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1139/CJFR-2020-0353", "year": 2021, "title": "Trends in wildfire burn severity across Canada, 1985 to 2015", "abstract": " Burn severity is an important component of the fire regime that has not yet been fully characterized for the forests of Canada. The objectives of this study were to (i) create a Canada-wide geospatial database of burn severity for wildland fires across forested regions of Canada from 1985 to 2015, and (ii) use this database to evaluate seasonal and annual trends in burn severity across Canada and regionally using two different regional units (ecozones and Homogeneous Fire Regime zones). We developed the 30 m resolution geospatial Canadian Landsat Burn Severity (CanLaBS) product from Landsat imagery, using values of pre-fire to post-fire differences in normalized burn ratios (dNBRs) for nearly 60 Mha of area burned across Canadas forests from 1985 to 2015, complemented with estimates of pre-fire forest composition, crown closure, and biomass. Our results suggest that burn severity is generally lower in spring fires than in summer ones nationally and in almost every regional unit. We found no consistent relationship between burn severity and annual area burned across ecozones. Finally, we observed a small but significant decrease in burn severity from 1985 to 2015 across Canada, although this is regionally variable. The CanLaBS database is publicly available at https://doi.org/10.23687/b1f61b7e-4ba6-4244-bc79-c1174f2f92cd . ", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.157322", "year": 2022, "title": "Reassessment of carbon emissions from fires and a new estimate of net carbon uptake in Russian forests in 2001\u20132021", "abstract": "Russia has the largest forest area on earth. Its boreal forests officially store about 97 Pg C, which significantly affect the global carbon cycle. In recent years, forest fires have been intensifying on the planet, leading to increased carbon emissions. Here we review how differences in fire control management of Russian forests affect fire related emissions. Carbon emissions due to fire were estimated using satellite data and compared to official reports for 20012021. We found that the relative areas affected by fire did differ between different fire protection zones, and 89 % of the area burnt was in forests controlled by fire-fighting aircraft or areas without protection. As a result, 417.7 Mha of poor or unprotected Russian forests (42 % of total) account about a half of total carbon emissions. According to our estimates, the average area of burnt forests in Russia was about 8.3 Mha per year between 2016 and 2021, resulting in annual carbon emission of 193 million metric tons (Mt) C emissions, and 53 % of them were from unprotected forest. These estimated carbon emissions are significantly higher than official national reports (79 Mt C yr1). We estimated that net carbon uptake for Russia for 20152021 was about 333 37 Mt C, which is roughly double the official estimates. Our results highlight large spatial differences in fire protection and prevention strategies in fire related emissions. The so-called control zone which stretches across large parts of Eastern Russia has no fire control and is the region of major recent fires. Our study shows that to estimate the Russian forest carbon balance it is critical to include this area. Implementation of some forest management in the remote areas (i.e., control zone) would help to decrease forest loss and resulting carbon emissions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2022GL098797", "year": 2022, "title": "Impacts of the Western Pacific and Indian Ocean warm pools on wildfires in Yunnan, Southwest China: Spatial patterns with inter\u2010and intra\u2010annual variations", "abstract": "The Indo-Pacific warm pool affects the regional climatic conditions in Southeast Asia mediated by the Western Pacific (WP) and Indian Ocean (IO) monsoons, which are recognized as critical regulators of wildfires in this region. Our study explored the spatiotemporal effects of the warm pools on wildfire records in Yunnan, Southwest China. We showed the interannual records had a negative relationship with the simultaneous WP warm pool area index. The Ailao Mountains in the central Yunnan could be a geographical barrier that blocked the influences of the WP warm pool from the east side. For the intraannual changes, the wildfire number variations had a stronger connection to the IO warm pool dynamics than the WP. Our study provided the novel evidence on the teleconnection between the Indo-Pacific warm pool dynamics and regional environmental processes in Yunnan, also indicating this area as a part of the transitional zone between the two warm pools.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/GMD-15-1899-2022", "year": 2022, "title": "Building a machine learning surrogate model for wildfire activities within a global Earth system model", "abstract": "Abstract. Wildfire is an important ecosystem process, influencing land biogeophysical and biogeochemical dynamics and atmospheric composition. Fire-driven loss of vegetation cover, for example, directly modifies the surface energy budget as a consequence of changing albedo, surface roughness, and partitioning of sensible and latent heat fluxes. Carbon dioxide and methane emitted by fires contribute to a positive atmospheric forcing, whereas emissions of carbonaceous aerosols may contribute to surface cooling. Process-based modeling of wildfires in Earth system land models is challenging due to limited understanding of human, climate, and ecosystem controls on fire counts, fire size, and burned area. Integration of mechanistic wildfire models within Earth system models requires careful parameter calibration, which is computationally expensive and subject to equifinality. To explore alternative approaches, we present a deep neural network (DNN) scheme that surrogates the process-based wildfire model with the Energy Exascale Earth System Model (E3SM) interface. The DNN wildfire model accurately simulates observed burned area with over 90 % higher accuracy with a large reduction in parameterization time compared with the current process-based wildfire model. The surrogate wildfire model successfully captured the observed monthly regional burned area during validation period 2011 to 2015 (coefficient of determination, R2=0.93). Since the DNN wildfire model has the same input and output requirements as the E3SM process-based wildfire model, our results demonstrate the applicability of machine learning for high accuracy and efficient large-scale land model development and predictions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1007/S11676-022-01487-0", "year": 2022, "title": "Geospatial characteristics of fire occurrences in southern hemispheric Africa and Madagascar during 20012020", "abstract": "For this study of long-term spatial patterns and trends of active fires in southern hemispheric Africa and on Madagascar from 2001 to 2020, active fire data from the MODIS FIRMS global fire data products were analyzed. The annual center of fire concentration tended to migrate toward the preserved rainforests and nature conservation areas in the Congo Basin and the mountain forests on the northeastern coast of Madagascar. Fire frequency varied seasonally at both study areas. We used geostatistical analysis techniques, such as measures of dispersion and emerging hot spot analysis, to reveal long-term trends in spatial patterns of fire events. In southern hemispheric Africa, the observed active fires tended to drift northward toward the Zambia-DRC border in the Congo basin. This northward migration progressed toward humid rainforests, which were better suited to sustaining repeated fire events. On Madagascar, the observed active fires tended to migrate toward the east coast in protected mountain forests. The spatial patterns of long-term trends showed a concentration of fires in the tropical regions of southern hemispheric Africa. Moreover, smaller clusters of new hot spots were located over eastern South Africa, overlapping with undifferentiated woodlands. On Madagascar, both hot and cold spots were identified and were separated by the highland region in the center of the island. Most of the eastern island was characterized by cold spots that received less precipitation than did the rest of the island. The presence of increasing hots spots in the densely vegetated areas highlights the urgent need for fire prevention and management in this region.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.JHYDROL.2022.128242", "year": 2022, "title": "Linking fire-induced evapotranspiration shifts to streamflow magnitude and timing in the western United States", "abstract": "The impact of wildfire on water availability is a critical issue in the western United States. Because actual evapotranspiration (ETa) constitutes the largest loss in the terrestrial water budget, it has been suggested that fire-induced ETa reduction is a primary driver of elevated post-fire discharge. Ten gaged watersheds with burns exceeding 5% of their total contributing drainage area were selected from California, Oregon, Montana, Utah, New Mexico, and Colorado. Continuous daily stream gage data were compiled, and 30-meter ETa estimates were calculated with the Operational Simplified Surface Energy Balance (SSEBop) model. Fire-induced ETa shifts were quantified with statistical tests that compared pre and post-fire monthly ETa in burned and unburned pixels; the dampening effect of scale was also evaluated by repeating tests on all pixels from the entire basin. As streamflow data are point measurements that aggregate a large spatial area, additional statistical methods were required to isolate the effect of fire from climate on baseflow and runoff. Key findings include a) significant fire-induced ETa reductions were only distinguishable in basin-scale monthly datasets when at least 73% of the basin burned, b) the effect of wildfire disturbance on streamflow magnitude was seasonably variable, c) streamflow was modified in basins with as little as 6% burned drainage area; however, shifts only persisted beyond the fifth post-fire year where more than three-quarters of the basin was fire-impacted, and d) surplus water from ETa reduction was sufficient to account for boosted fire-induced streamflow. Where fire-induced streamflow increases were not significantly correlated with ETa anomaly, other fire-impacted landscape processes may have contributed to modified runoff generation and routing. Where fire reduced ETa but streamflow shifts were not detected, compensatory ETa pathways may have consumed the excess water before it reached the gage. Findings suggest that water providers with small source-water collection areas have higher relative risk for fire-induced hydromodification than providers with larger or more diversified supply portfolios. Results also illustrate the tendency of overarching climate signals to mask or artificially boost the apparent effect of landscape disturbance on streamflow at the basin outlet.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1002/2016JD025688", "year": 2017, "title": "In situ measurements of water uptake by black carbon\u2010containing aerosol in wildfire plumes", "abstract": "Water uptake by black carbon (BC)-containing aerosol was quantified in North American wildfire plumes of varying age (1 to 40 h old) sampled during the SEAC4RS mission (2013). A Humidified Dual SP2 (HD-SP2) is used to optically size BC-containing particles under dry and humid conditions from which we extract the hygroscopicity parameter, \u03ba, of materials internally mixed with BC. Instrumental variability and the uncertainty of the technique are briefly discussed. An ensemble average \u03ba of 0.04 is found for the set of plumes sampled, consistent with previous estimates of bulk aerosol hygroscopicity from biomass burning sources. The temporal evolution of \u03ba in the Yosemite Rim Fire plume is explored to constrain the rate of conversion of BC-containing aerosol from hydrophobic to more hydrophilic modes in these emissions. A BC-specific \u03ba increase of 0.06 over 40 h is found, fit well with an exponential curve corresponding to a transition from a \u03ba of 0 to a \u03ba of 0.09 with an e-folding time of 29 h. Although only a few percent of wildfire particles contain BC, a similar \u03ba increase is estimated for bulk aerosol and the measured aerosol composition is used to infer that the observed \u03ba change is driven by a combination of incorporation of ammonium sulfate and oxidation of existing organic materials. Finally, a substantial fraction of wildfire-generated BC-containing aerosol is calculated to be active as cloud condensation nuclei shortly after emission likely indicating efficient wet removal. These results can constrain model treatment of BC from wildfire sources.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ATMOSENV.2010.10.038", "year": 2011, "title": "Nationwide summer peaks of OC/EC ratios in the contiguous United States", "abstract": "The ratios of observed organic carbon (OC) to elemental carbon (EC) from the rural sites of the IMPROVE network are analyzed for the 5-year period from 2000 to 2004. Among these years, nationwide OC/EC peaks are observed most consistently in the summer of 2002. Several potential factors are analyzed, including biomass burning, secondary organic aerosols (SOA) formation from biogenic sources and in-cloud processing, long-range transport from East Asia, and meteorological conditions over the U.S. We find that biomass burning and SOA formation make the most significant contributions using the global GEOS-Chem model simulations. The effect of model estimated in-cloud SOA formation is significant compared to the estimate of (non-cloud) biogenic SOA. The impacts of Canadian and western U.S. fires are larger than fires in Russia or Mexico in summer. The dry meteorological condition of the summer of 2002 tends to promote higher OC/EC ratios by inducing larger fire emissions, SOA formation, and a longer OC lifetime.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1109/TGRS.2022.3192974", "year": 2022, "title": "Next Day Wildfire Spread: A Machine Learning Dataset to Predict Wildfire", "abstract": "Predicting wildfire spread is critical for land management and disaster preparedness. To this end, we present `Next Day Wildfire Spread,' a curated, large-scale, multivariate data set of historical wildfires aggregating nearly a decade of remote-sensing data across the United States. In contrast to existing fire data sets based on Earth observation satellites, our data set combines 2D fire data with multiple explanatory variables (e.g., topography, vegetation, weather, drought index, population density) aligned over 2D regions, providing a feature-rich data set for machine learning. To demonstrate the usefulness of this data set, we implement a neural network that takes advantage of the spatial information of this data to predict wildfire spread. We compare the performance of the neural network with other machine learning models: logistic regression and random forest. This data set can be used as a benchmark for developing wildfire propagation models based on remote sensing data for a lead time of one day.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.RSE.2021.112800", "year": 2022, "title": "Mapping burn severity in the western Italian Alps through phenologically coherent reflectance composites derived from Sentinel-2 imagery", "abstract": "Deriving burn severity from multispectral satellite data is a widely adopted approach to infer the degree of environmental change caused by fire. Burn severity maps obtained by thresholding bi-temporal indices based on pre- and post-fire Normalized Burn Ratio (NBR) can vary substantially depending on temporal constraints such as matched acquisition and optimal seasonal timing. Satisfying temporal requirements is crucial to effectively disentangle fire and non-fire induced spectral changes and can be particularly challenging when only a few cloud-free images are available. Our study focuses on 10 wildfires that occurred in mountainous areas of the Piedmont Region (Italy) during autumn 2017 following a severe and prolonged drought period. Our objectives were to: (i) generate reflectance composites using Sentinel-2 imagery that were optimised for seasonal timing by embedding spatial patterns of long-term land surface phenology (LSP); (ii) produce and validate burn severity maps based on the modelled relationship between bi-temporal indices and field data; (iii) compare burn severity maps obtained using either a pair of cloud-free Sentinel-2 images, i.e. paired images, or reflectance composites. We proposed a pixel-based compositing algorithm coupling the weighted geometric median and thematic spatial information, e.g. long-term LSP metrics derived from the MODIS Collection 6 Land Cover Dynamics Product, to rank all the clear observations available in the growing season. Composite Burn Index data and bi-temporal indices exhibited a strong nonlinear relationship (R2 > 0.85) using paired images or reflectance composites. Burn severity maps attained overall classification accuracy ranging from 76.9% to 83.7% (Kappa between 0.61 and 0.72) and the Relative differenced NBR (RdNBR) achieved the best results compared to other bi-temporal indices (differenced NBR and Relativized Burn Ratio). Improvements in overall classification accuracy offered by the calibration of bi-temporal indices with the dNBR offset were limited to burn severity maps derived from paired images. Reflectance composites provided the highest overall classification accuracy and differences with paired images were significant using uncalibrated bi-temporal indices (4.4% to 5.2%) while they decreased (2.8% to 3.2%) when we calibrated bi-temporal indices derived from paired images. The extent of the high severity category increased by ~19% in burn severity maps derived from reflectance composites (uncalibrated RdNBR) compared to those from paired images (calibrated RdNBR). The reduced contrast between healthy and burnt conditions associated with suboptimal seasonal timing caused an underestimation of burnt areas. By embedding spatial patterns of long-term LSP metrics, our approach provided consistent reflectance composites targeted at a specific phenological stage and minimising non-fire induced inter-annual changes. Being independent from the multispectral dataset employed, the proposed pixel-based compositing approach offers new opportunities for operational change detection applications in geographic areas characterised by persistent cloud cover.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1038/S41598-020-67530-4", "year": 2020, "title": "Observational evidence of wildfire-promoting soil moisture anomalies", "abstract": "Wildfires can destroy property and vegetation, thereby threatening peoples livelihoods and food security. Soil moisture and biomass are important determinants of wildfire hazard. Corresponding novel satellite-based observations therefore present an opportunity to better understand these disasters globally and across different climate regions. We sampled 9,840 large wildfire events from around the globe, between 2001 and 2018, along with respective surface soil moisture and biomass data. Using composites across fire events in similar climate regions, we show contrasting soil moisture anomalies in space and time preceding large wildfires. In arid regions, wetter-than-average soils facilitate sufficient biomass growth required to fuel large fires. In contrast, in humid regions, fires are typically preceded by dry soil moisture anomalies, which create suitable ignition conditions and flammability in an otherwise too wet environment. In both regions, soil moisture anomalies continuously decrease in the months prior to fire occurrence, often from above-normal to below-normal. These signals are most pronounced in sparsely populated areas with low human influence, and for larger fires. Resolving natural soil moisturefire interactions supports fire modelling and facilitates improved fire predictions and early warning.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1080/02827581.2021.1918239", "year": 2021, "title": "Maximum entropy-based forest fire likelihood mapping: analysing the trends, distribution, and drivers of forest fires in Sikkim Himalaya", "abstract": "The recent episodes of forest fires in Brazil and Australia of 2019 are tragic reminders of the hazards of forest fire. Globally incidents of forest fire events are on the rise due to human encroachment into the wilderness and climate change. Sikkim with a forest cover of more than 47%, suffers seasonal instances of frequent forest fire during the dry winter months. To address this issue, a GIS-aided and MaxEnt machine learning-based forest fire prediction map has been prepared using a forest fire inventory database and maps of environmental features. The study indicates that amongst the environmental features, climatic conditions and proximity to roads are the major determinants of forest fire. Model validation criteria like ROC curve, correlation coefficient, and Cohen's Kappa show a good predictive ability (AUC = 0.95, COR = 0.81, = 0.78). The outcomes of this study in the form of a forest fire prediction map can aid the stakeholders of the forest in taking informed mitigation measures.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/GMD-15-1545-2022", "year": 2022, "title": "A parameterization of long-continuing-current (LCC) lightning in the lightning submodel LNOX (version 3.0) of the Modular Earth Submodel System (MESSy, version 2.54)", "abstract": "Abstract. Lightning flashes can produce a discharge in which a continuing electrical current flows for more than 40 ms. Such flashes are proposed to be the main precursors of lightning-ignited wildfires and also to trigger sprite discharges in the mesosphere. However, lightning parameterizations implemented in global atmospheric models do not include information about the continuing electrical current of flashes. The continuing current of lightning flashes cannot be detected by conventional lightning location systems. Instead, these so-called long-continuing-current (LCC) flashes are commonly observed by extremely low-frequency (ELF) sensors and by optical instruments located in space. Reports of LCC lightning flashes tend to occur in winter and oceanic thunderstorms, which suggests a connection between weak convection and the occurrence of this type of discharge. In this study, we develop a parameterization of LCC lightning flashes based on a climatology derived from optical lightning measurements reported by the Lightning Imaging Sensor (LIS) on board the International Space Station (ISS) between March 2017 and March 2020. We use meteorological data from reanalyses to develop a global parameterization that uses vertical velocity at the 450 hPa pressure level as a proxy for the ratio of LCC to total lightning in thunderstorms. We implement this parameterization into the LNOX submodel of the Modular Earth Submodel System (MESSy) for usage within the European Center HAMburg general circulation model (ECHAM)/MESSy Atmospheric Chemistry (EMAC) model and compare the observed and simulated climatologies of LCC lightning flashes using six different lightning parameterizations. We find that the best agreement between the simulated and observed spatial distribution is obtained when using a novel combined lightning parameterization based on the cloud-top height over land and on the convective precipitation over ocean.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1088/1748-9326/AB9DB2", "year": 2020, "title": "Observed changes in fire patterns and possible drivers over Central Africa", "abstract": "Abstract\r\n \r\n Fire is an integral part of Earths system that links regional and global biogeochemical cycles, human activities, and ecosystems. Global estimates for biomass burning indicate that Africa is responsible for ~70% of global burned area and ~50% of fire-related carbon emissions. Previous studies have documented an overall decline in burned area in the African continent, but changes in fire patterns, such as the frequency and size of different fire categories, have not been assessed. In this study, long-term fire trends were investigated using the latest burned area data from the MODerate resolution Imaging Spectroradiometer (MODIS) and the Global Fire Emission Database (GFED4s) over Central Africa (10E40E, 15N15S). A 3D (latitude, longitude, time) connected-component labeling algorithm was applied to identify individual fires and their sizes. The results show a decline in burned area by 2.73.2 Mha yr\r\n 1\r\n (~1.3% yr\r\n 1\r\n ) for the period 20032017, particularly in northern Central Africa. This decline was attributed to significant decreases in both fire frequency and size, particularly for large fires (>100 ha) which contribute to ~90% of the total burned area. Burned area declined in tropical savannas and grasslands but increased at the edges of the Congolese rainforest. A random forest regression model was applied to quantify the influences of climatic conditions, fuel availability, and agricultural activity on burned area changes. Overall, suppressed fuel, increased dry season length, and decreased rainfall contributed to significant declines in burned area in savannas and grasslands. At the edges of the southern Congolese rainforest, suppressed rainfall and warmer temperature were responsible for the increased burned area.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1007/S41976-020-00038-7", "year": 2020, "title": "Changes in Growing Season Phenology Following Wildfires in Alaska", "abstract": "Trends and geographic patterns of change in vegetation phenology metrics and snowmelt timing from the MODerate resolution Imaging Spectroradiometer (MODIS) satellite data sets were analyzed across the state of Alaska for all wildfires that burned during the years 2004 and 2005. Phenology metric patterns (over the period 2000 to 2018) derived from the normalized difference vegetation index (NDVI) time-series at 250-m resolution tracked changes in the growing season length and integrated greenness cover over the past two decades. NDVI metrics showed that end of the growing season timing (EOST) and integrated greenness increased significantly in the majority of severely burned areas in Interior Alaska over the past decade particularly in low elevation zones below 500 m. In years with relatively early snowmelt dates (3 to 10 days earlier than the long-term mean), lower plant growth was observed over the ensuing growing season, potentially due to lower snow water inputs that can maintain available soil moisture levels for plant growth into the mid- and late-summer months. Statewide trends in MODIS phenology metrics indicate that the predominant vegetation cover type in most regrowing burned areas of Interior Alaska a decade post-fire is still deciduous shrub and young tree cover. Several large fires of special interest were identified to monitor with remote sensing and continue to track long-term recovery patterns and rates.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5751/ES-13133-270206", "year": 2022, "title": "Water quality and forest restoration in the Lake Tahoe basin: impacts of future management options", "abstract": "Land managers in the Lake Tahoe basin are considering increasing the use of prescribed fire and forest thinning to restore conditions that will be more resilient to wildfires. However, such restorative treatments also constitute disturbances that could increase sediment and nutrient loads. We examined whether the water-quality impacts from future treatments are likely to be lower compared to the potential impacts from future wildfires under various climate change scenarios. We applied an online interface for the Water Erosion Prediction Project (WEPP) model in combination with a landscape change model (LANDIS-II) to evaluate the effects of different combinations of thinning and prescribed burning on fine sediment (< 2 mm), very fine sediment (< 16 m), and phosphorus over time. First, we generated results based on historic weather data for soil disturbance conditions, including: an undisturbed baseline, a uniform thinning treatment; a uniform prescribed fire treatment; and uniform low, moderate, and high wildfire burn severity. Residual ground cover declined in that order, and expected loads of sediment and phosphorus increased. We then combined the estimated loads from hillslopes with projected management-disturbance regimes across each decade of the next century. We found that expected sediment and phosphorus loads were lower under the scenario that emphasized thinning, whereas scenarios that increased prescribed burning resulted in loads that were comparable to scenarios that involved less treatment. These results reflect the finding from the WEPP analysis that prescribed burning is expected to reduce ground cover more than is thinning. Our analysis supports efforts to increase fuel reduction treatments to mitigate future wildfires, but it also suggests that preventative treatments may not avoid a long-term decline in water quality as wildfires increase with climate change.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1177/23998083211039854", "year": 2021, "title": "Modeling the relationships between historical redlining, urban heat, and heat-related emergency department visits: An examination of 11 Texas cities", "abstract": "Place-based structural inequalities can have critical implications for the health of vulnerable populations. Historical urban policies, such as redlining, have contributed to current inequalities in exposure to intra-urban heat. However, it is unknown whether these spatial inequalities are associated with disparities in heat-related health outcomes. The aim of this study is to determine the relationships between historical redlining, intra-urban heat conditions, and heat-related emergency department visits using data from 11 Texas cities. At the zip code level, the proportion of historical redlining was determined, and heat exposure was measured using daytime and nighttime land surface temperature (LST). Heat-related inpatient and outpatient rates were calculated based on emergency department visit data that included ten categories of heat-related diseases between 2016 and 2019. Regression or spatial error/lag models revealed significant associations between higher proportions of redlined areas in the neighborhood and higher LST (Coef. = 0.0122, 95% CI = 0.00390.0205). After adjusting for indicators of social vulnerability, neighborhoods with higher proportions of redlining showed significantly elevated heat-related outpatient visit rate (Coef. = 0.0036, 95% CI = 0.00070.0066) and inpatient admission rate (Coef. = 0.0018, 95% CI = 0.00010.0035). These results highlight the role of historical discriminatory policies on the disparities of heat-related illness and suggest a need for equity-based urban heat planning and management strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.5194/ACP-18-5639-2018", "year": 2018, "title": "Using TES retrievals to investigate PAN in North American biomass burning plumes", "abstract": "Abstract. Peroxyacyl nitrate (PAN) is a critical atmospheric reservoir for nitrogen oxide radicals, and plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America from July 2006 to July 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer ( 750 hPa) even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. Depending on the year, 1532 % of cases where elevated PAN is identified in TES observations (retrievals with degrees of freedom (DOF) > 0.6) overlap smoke plumes during July. Of all the retrievals attempted in the July 2006 to July 2009 study period, 18 % is associated with smoke . A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO) > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1088/1748-9326/ABFC04", "year": 2021, "title": "Environmental and political implications of underestimated cropland burning in Ukraine", "abstract": "Abstract\r\n Open burning is illegal in Ukraine, yet Ukraine has, on average, 300 times more fire activity per year (20012019) than most European countries. In 2016 and 2017, 47% of Ukraine was identified as cultivated area, with a total of 70% of land area dedicated to agricultural use. Over 57% of all active fires in Ukraine detected using space-borne Visible Infrared Imaging Radiometer Suite (VIIRS) during 2016 and 2017 were associated with pre-planting field clearing and post-harvest crop residue removal, meaning that the majority of these fires are preventable. Due to the small size and transient nature of cropland burns, satellite-based burned area (BA) estimates are often underestimated. Moreover, traditional spectral-based BA algorithms are not suitable for distinguishing burned from plowed fields, especially in the black soil regions of Ukraine. Therefore, we developed a method to estimate agricultural BA by calibrating VIIRS active fire data with exhaustively mapped cropland reference areas (42 958 fields). Our study found that cropland BA was significantly underestimated (by 30%63%) in the widely used Moderate Resolution Imaging Spectroradiometer-based MCD64A1 BA product, and by 95%99.9% in Ukraines National Greenhouse Gas Inventory. Although crop residue burns are smaller and emit far less emissions than larger wildfires, reliable monitoring of crop residue burning has a number of important benefits, including (a) improving regional air quality models and the subsequent understanding of human health impacts due to the proximity of crop residue burns to urban locations, (b) ensuring an accurate representation of predominantly smaller fires in regional emission inventories, and (c) increasing awareness of often illegal managed open burning to provide improved decision-making support for policy and resource managers.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1109/INGARSS51564.2021.9792002", "year": 2021, "title": "Unfolding the contribution of environmental and anthropogenic variables in forest fire over western Himalayan fire regime", "abstract": "In last few decades, a surge of uncontrolled wild and forest fire has been observed over biomes, mostly from tropical and subtropical regions. The present study has disentangled the contribution of different environmental and anthropogenic factors in forest fire over the western Himalayan (Uttarakhand and Himachal Pradesh) fire regime, which is an active fire hotspot in India. Fire-CCI v5.1 data was used to labelled fire and non-fire pixel. The climatic (e.g. maximum and minimum temperature, precipitation, solar radiation, vapour pressure, wind speed, water vapour deficit, soil moisture and palmer drought index), physiographic (elevation, slope, aspect and roughness), anthropogenic (population density and human modification) and locational (latitude and longitude) variables were utilized to unfold their contribution in forest fire by the aid of Random Forest (RF) a machine learning technique. After parameterization, a 10-fold cross-validation RF model was built over the whole dataset and the average overall accuracy, precision, recall, F-1 score and overall accuracy were estimated as 0.94 (0.002), 0.86 (0.003), 0.91 (0.002) and 0.91 (0.002), respectively. Furthermore, the whole dataset (2005-2018) was divided into two parts, training set (2005-2017) and testing (2018), to get a robust model. The testing accuracy (overall accuracy = 0.82, precision =0.79, recall = 0.95, F1 score = 0.86 and area under curve (AUC) = 0.95) suggested a reliable performance of RF model in forest fire classification (fire and non-fire). The contributions of the selected variables were retrieved from the feature importance of the RF model. The maximum temperature exhibited the highest importance, followed by elevation, minimum temperature and location variable (latitude and longitude). The population density and human modification (gHM) are moderately contributing to western Himalayan forest fire. Keywords: Forest fire; Western Himalaya; Random Forest", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.RSASE.2018.04.010", "year": 2018, "title": "Use of imaging spectroscopy and LIDAR to characterize fuels for fire behavior prediction", "abstract": "To protect ecosystem services and the increasing wildland urban interface in a world with fire, comprehensive maps of wildland fuels are needed to predict fire behavior and effects. Traditionally, fuels have been categorized into a classification scheme whereby a single metric represents vegetation composition and structure, which can then be parameterized based on variable vegetation amount and condition. Remote sensing has been used to extrapolate between known field plots across the landscape, however until recently, those technologies have had limited ability to characterize fuels (e.g., composition, horizontal and vertical connectivity). Using new technologies (imaging spectroscopy and LIDAR), the objectives of this study are to assess: 1) how fuel characteristics observed from remote sensing affect categorical fuel classifications, and 2) how fuel characteristics affect landscape-scale fire behavior (spread rate, areal extent and perimeter). The analysis was conducted over the 2014 California King Fire that burned ~40,000 ha over lands with varying use and history and has unique remote sensing observations from before and after the fire. This analysis compares fuel classifications from a synergistic field, model, and Landsat approach (LANDFIRE) and products derived from the Airborne Visible/Infrared Imaging Spectrometer and LIDAR (MapFUELS). Each classification focuses on different fuel characteristics, which were then used to compare differences in a fire simulation model (CAWFE) and actual fire behavior. The results show that fuel characteristic inputs such as horizontal connectivity or fuel type and vertical structure affect fire spread rate and final fire extent (respectively). These results present the opportunity for future integration of fuel characteristics observed at coarser resolutions (900 m2) into predictions of fire behavior a similar spatial resolutions (as opposed to the current standard based on empirical relationships between fuel and fire behavior at ~12 m2 resolution).", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/ATMOS12060755", "year": 2021, "title": "2019-20 Australian Bushfires and Anomalies in Carbon Monoxide Surface", "abstract": "In Australia, bushfires are a natural part of the countrys landscape and essential for the regeneration of plant species; however, the 201920 bushfires were unprecedented in their extent and intensity. This paper is focused on the 201920 Australian bushfires and the resulting surface and column atmospheric carbon monoxide (CO) anomalies around Wollongong. Column CO data from the ground-based Total Carbon Column Observing Network (TCCON) and Network for the Detection of Atmospheric Composition Change (NDACC) site in Wollongong are used together with surface in situ measurements. A systematic comparison was performed between the surface in situ and column measurements of CO to better understand whether column measurements can be used as an estimate of the surface concentrations. If so, satellite column measurements of CO could be used to estimate the exposure of humans to CO and other fire-related pollutants. We find that the enhancements in the column measurements are not always significantly evident in the corresponding surface measurements. Topographical features play a key role in determining the surface exposures from column abundance especially in a coastal city like Wollongong. The topography at Wollongong, combined with meteorological effects, potentially exacerbates differences in the column and surface. Hence, satellite column amounts are unlikely to provide an accurate reflection of exposure at the ground during major events like the 20192020 bushfires.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1088/1748-9326/AC8696", "year": 2022, "title": "A low-order dynamical model for fire-vegetation-climate interactions", "abstract": "Abstract\r\n Climate conditions play a key role in determining the occurrence and severity of wildfires. Despite the impacts of wildfires on ecosystems, human livelihoods, and air quality, little is known conceptually about how natural or anthropogenic shifts in climate may influence the fire activity on a regional or global scale. Here, we introduce a new low order dynamical model that describes the nonlinear interactions between climate, vegetation (fire fuel) and fire probabilities. This 1-dimensional model describes the influence of precipitation and temperature on burned area and fuel availability. Estimating key parameters from observations, the model successfully reproduces the spatio-temporal variability of wildfire occurrences, particularly, in semi-arid regions in Africa, South America, and northern Australia. The fidelity of the model translates into a high degree of longer-term predictability of fire conditions in these vulnerable regions. Our new low-order modeling framework may provide guidance to forestry managers to assess fire risks under present and future climate conditions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/FIRE4030052", "year": 2021, "title": "Mapping Wetland Burned Area from Sentinel-2 across the Southeastern", "abstract": "Prescribed fires and wildfires are common in wetland ecosystems across the Southeastern United States. However, the wetland burned area has been chronically underestimated across the region due to (1) spectral confusion between open water and burned area, (2) rapid post-fire vegetation regrowth, and (3) high annual precipitation limiting clear-sky satellite observations. We developed a machine learning algorithm specifically for burned area in wetlands, and applied the algorithm to the Sentinel-2 archive (20162019) across the Southeastern US (>290,000 km2). Combining Landsat-8 imagery with Sentinel-2 increased the annual clear-sky observation count from 17 to 46 in 2016 and from 16 to 78 in 2019. When validated with WorldView imagery, the Sentinel-2 burned area had a 29% and 30% omission and commission rates of error for burned area, respectively, compared to the US Geological Survey Landsat-8 Burned Area Product (L8 BA), which had a 47% and 8% omission and commission rate of error, respectively. The Sentinel-2 algorithm and the L8 BA mapped burned area within 78% and 60% of wetland fire perimeters (n = 555) compiled from state and federal agencies, respectively. This analysis demonstrated the potential of Sentinel-2 to support efforts to track the burned area, especially across challenging ecosystem types, such as wetlands.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/BG-14-2755-2017", "year": 2017, "title": "Changing patterns of fire occurrence in proximity to forest edges, roads and rivers between NW Amazonian countries", "abstract": "Abstract. Tropical forests in NW Amazonia are highly threatened by the expansion of the agricultural frontier and subsequent deforestation. Fire is used, both directly and indirectly, in Brazilian Amazonia to propagate deforestation and increase forest accessibility. Forest fragmentation, a measure of forest degradation, is also attributed to fire occurrence in the tropics. However, outside the Brazilian Legal Amazonia the role of fire in increasing accessibility and forest fragmentation is less explored. In this study, we compared fire regimes in five countries that share this tropical biome in the most north-westerly part of the Amazon Basin (Venezuela, Colombia, Ecuador, Peru and Brazil). We analysed spatial differences in the timing of peak fire activity and in relation to proximity to roads and rivers using 12 years of MODIS active fire detections. We also distinguished patterns of fire in relation to forest fragmentation by analysing fire distance to the forest edge as a measure of fragmentation for each country. We found significant hemispheric differences in peak fire occurrence with the highest number of fires in the south in 2005 vs. 2007 in the north. Despite this, both hemispheres are equally affected by fire. We also found difference in peak fire occurrence by country. Fire peaked in February in Colombia and Venezuela, whereas it peaked in September in Brazil and Peru, and finally Ecuador presented two fire peaks in January and October. We confirmed the relationship between fires and forest fragmentation for all countries and also found significant differences in the distance between the fire and the forest edge for each country. Fires were associated with roads and rivers in most countries. These results can inform land use planning at the regional, national and subnational scales to minimize the contribution of road expansion and subsequent access to the Amazonian natural resources to fire occurrence and the associated deforestation and carbon emissions.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.2478/JOHH-2022-0029", "year": 2022, "title": "Open data application to evaluate exposure of wildfire to water resources: A case study in Johor, Malaysia", "abstract": "Abstract\r\n Climate change impacts wildfire events as well as water availability. Exposure of water resources to wildfire can reduce water quality supplied to humans and resulting health problems. On the other hand, water resources such as rivers and ponds are essential in wildfire firefighting. This paper intended to assess spatially the exposure of water resources to wildfire. A case study in Johor, Malaysia is utilised to asses and determine locations of water bodies in an area which are vulnerable to wildfire. Post wildfire runoff water can contaminate water resources. Fire data collected by MODIS from 20002020 are used to create a hotspot map. Water resources and waterbody data originated from Department of Surveying and Mapping Malaysia used to identify the stream and dams that are exposed to wildfire. 5 class exposure level has been set to show the degree of closeness of water resources to wildfire hotspot area. Using the spatial analysis method, low to high level of potential wildfire-water exposures were able to be locate. Analysis shows, 7% of Johors water sources is exposed to medium levels of wildfire, while just 1% is exposed to the highest levels. The majority of the streams have very low levels of exposure. In addition, the wildfire-water exposure map aids in first respondent preparedness and planning.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1038/S41561-019-0403-X", "year": 2019, "title": "Global fire emissions buffered by the production of pyrogenic carbon", "abstract": "Landscape fires burn 35 million km2 of the Earths surface annually. They emit 2.2 Pg of carbon per year to the atmosphere, but also convert a significant fraction of the burned vegetation biomass into pyrogenic carbon. Pyrogenic carbon can be stored in terrestrial and marine pools for centuries to millennia and therefore its production can be considered a mechanism for long-term carbon sequestration. Pyrogenic carbon stocks and dynamics are not considered in global carbon cycle models, which leads to systematic errors in carbon accounting. Here we present a comprehensive dataset of pyrogenic carbon production factors from field and experimental fires and merge this with the Global Fire Emissions Database to quantify the global pyrogenic carbon production flux. We found that 256 (uncertainty range: 196340) Tg of biomass carbon was converted annually into pyrogenic carbon between 1997 and 2016. Our central estimate equates to 12% of the annual carbon emitted globally by landscape fires, which indicates that their emissions are buffered by pyrogenic carbon production. We further estimate that cumulative pyrogenic carbon production is 60 Pg since 1750, or 3340% of the global biomass carbon lost through land use change in this period. Our results demonstrate that pyrogenic carbon production by landscape fires could be a significant, but overlooked, sink for atmospheric CO2.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2020GL091875", "year": 2021, "title": "Impact of Amazonian Fires on Atmospheric CO2", "abstract": "Amazon rainforest fires have significant environmental and societal impacts, but the mechanism and impact of the fires on the regional and global carbon cycles have not been fully understood. Over the rainforest, less precipitation, higher surface temperature, and enhanced mid tropospheric sinking air over the eastern part of the Amazon characterized the fire/dry season. These meteorological conditions will facilitate more fires in the Amazon rainforest. Using the Orbiting Carbon Observatory 2 column CO2, we notice that there are \u223c2 ppm more CO2 over the Amazon compared with the surrounding area during the fire season. The higher concentrations of atmospheric CO2 are related to the surface biomass burning, enhanced sinking air over the eastern part of the Amazon, and surface winds. Results from this study can help us better understand the carbon sources and sinks over the Amazon during the fire/dry season.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/RS13020220", "year": 2021, "title": "Wildfire Damage Assessment over Australia Using Sentinel-2 Imagery and", "abstract": "Wildfires are major natural disasters negatively affecting human safety, natural ecosystems, and wildlife. Timely and accurate estimation of wildfire burn areas is particularly important for post-fire management and decision making. In this regard, Remote Sensing (RS) images are great resources due to their wide coverage, high spatial and temporal resolution, and low cost. In this study, Australian areas affected by wildfire were estimated using Sentinel-2 imagery and Moderate Resolution Imaging Spectroradiometer (MODIS) products within the Google Earth Engine (GEE) cloud computing platform. To this end, a framework based on change analysis was implemented in two main phases: (1) producing the binary map of burned areas (i.e., burned vs. unburned); (2) estimating burned areas of different Land Use/Land Cover (LULC) types. The first phase was implemented in five main steps: (i) preprocessing, (ii) spectral and spatial feature extraction for pre-fire and post-fire analyses; (iii) prediction of burned areas based on a change detection by differencing the pre-fire and post-fire datasets; (iv) feature selection; and (v) binary mapping of burned areas based on the selected features by the classifiers. The second phase was defining the types of LULC classes over the burned areas using the global MODIS land cover product (MCD12Q1). Based on the test datasets, the proposed framework showed high potential in detecting burned areas with an overall accuracy (OA) and kappa coefficient (KC) of 91.02% and 0.82, respectively. It was also observed that the greatest burned area among different LULC classes was related to evergreen needle leaf forests with burning rate of over 25 (%). Finally, the results of this study were in good agreement with the Landsat burned products.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-22-15021-2022", "year": 2022, "title": "South American 2020 regional smoke plume: intercomparison with previous years, impact on solar radiation, and the role of Pantanal biomass burning season", "abstract": "Abstract. The 2020 biomass burning season in Brazil was marked by an atypical amount of fire across the Pantanal biome, which led to high levels of smoke within the biome and downwind areas. The present study analyzes fire counts and smoke over Pantanal in 2020, comparing this particular year's data with those from the previous 17 years (20032019). Taking as reference the most-polluted years in this period, the regional smoke plume and its impact on surface solar radiation were also evaluated. In 2020, the regional smoke plume core covered an area of 2.6106 km2 at the peak of the burning season, an area well above that of the previous 6 years but smaller than areas observed in a more remote past, as in 2007 and 2010 (> 5.0106 km2). The smoke loading was lower (mean aerosol optical depth, AOD, of 550 nm; 0.7) than that of 2007 and 2010 (mean AOD 550 nm; 1.0). The plume radiation absorption efficiency, when compared with the previous year's plumes, did not present significant differences. Regarding the Pantanal burning season, it revealed some atypical features. Fire counts were up to 3.0 times higher than for the years from 2003 to 2019. Smoke loading over Pantanal, which is typically a fraction of that over Amazonia, was higher in 2020 than that over Amazonia, an indication that local smoke surpassed the smoke advection from upwind regions. The observed intraseasonal variability in smoke over Pantanal revealed to be largely driven by the nature of the burned areas in the biome. From September on, there was a significant increase in fire count in conservation and indigenous areas, where higher biomass density is present, which would explain the larger smoke plumes over Pantanal, even during October when the fire count was reduced. In October, the biome was covered by a thick smoke layer, which resulted in a mean deficit of surface solar radiation up to 200 W m2. Despite the Pantanal biomes' massive burning in 2020, the regional smoke plume was not far from its climatological features. Nevertheless, the Pantanal 2020 burning season represents the worst combination of a climate extreme applied to a fire-prone environment, coupled with inadequately enforced environmental regulations, from which there is much to be learned.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1029/2018GL078679", "year": 2018, "title": "A New Picture of Fire Extent, Variability, and Drought Interaction in Prescribed Fire Landscapes: Insights From Florida Government Records", "abstract": "Florida, United States, government records provide a new resource for studying fire in landscapes managed with prescribed fire. In Florida, most fire area (92%) is prescribed. Current satellite fire products, which underpin most air pollution emission inventories, detect only 25% of burned area, which alters airborne emissions and environmental impacts. Moreover, these satellite products can misdiagnose spatiotemporal variability of fires. Overall fire area in Florida decreases during drought conditions as prescribed fires are avoided, but satellite data do not reflect this pattern. This pattern is consistent with prescribed fire successfully reducing overall fire risk and damages. Human management of prescribed fires and fuels can, therefore, break the conventional link between drought and wildfire and play an important role in mitigating rising fire risk in a changing climate. These results likely apply in other regions of the world with similar fire regimes.", "labels": [] }, { "doi": "10.1201/9780429022036-9", "year": 2021, "title": "Satellite-based estimation of global CO2 emissions from biomass burning", "abstract": "In this study, we estimate the global CO2 emissions from biomass burning using satellite data. A polynomial regression function calibrated the traditional vegetation index (NDVI) for assessing the aboveground biomass (AGB) using a process-based model (VISIT). Also, soil organic matter (SOM) modeled values from VISIT were also integrated into emissions calculation. MODISs finer spatial resolution at 1 km enabled to detect of small fires (in spatial scales of several m to km) than the Global Fire Emissions Database (GFED) 4.1s product at 25 km. Fire radiative power (FRP) of MODIS was used as a dynamic combustion completeness ratio since it provides variable values for every fire event. We delineated the monthly dynamics of fire emissions (FEs) in detail in terms of scale and strength. We addressed the following objectices: (1) estimate global FE considering dynamic combustion completeness by using FRP of MODIS, (2) characterize seasonal and regional patterns of wildfires, and (3) report uncertainties in GFED4.1s compared to our estimates. Our results on monthly time-series FEs agreed well with the GFED data. The annual averages of carbon (C) emissions from FEs were 1.25 0.12 PgC/year compared to 1.68 0.15 PgC/year from the GFED.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1002/2016JD025216", "year": 2016, "title": "Investigating dominant characteristics of fires across the Amazon during 2005-2014 through satellite data synthesis of combustion signatures", "abstract": "Estimates of fire emissions remain uncertain due to limited constraints on the variations in fire characteristics. Here we demonstrate the utility of space-based observations of smoke constituents in addressing this limitation. We introduce a satellite-derived smoke index (SI) as an indicator of the dominant phase of large-scale fires. This index is calculated as the ratio of the geometric mean of observed fractional enhancements (due to fire) in carbon monoxide and aerosol optical depth to that of nitrogen dioxide. We assess the usefulness of this index on fires in the Amazon. We analyze the seasonal, regional, and interannual joint distribution of SI and fire radiative power (FRP) in relation to fire hotspots, land cover, Drought Severity Index, and deforestation rate estimates. We also compare this index with an analogous quantity derived from field data or emission inventories. Our results show that SI changes from low (more flaming) to high (more smoldering) during the course of a fire season, which is consistent with the changes in observed maximum FRPs from high to low. We also find that flaming combustion is more dominant in areas where deforestation fires dominate, while smoldering combustion has a larger influence during drought years when understory fires are more likely enhanced. Lastly, we find that the spatiotemporal variation in SI is inconsistent with current emission inventories. Although we recognize some limitations of this approach, our results point to the utility of SI as a proxy for overall combustion efficiency in the parameterization of fire emission models.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1134/S0001433811060041", "year": 2011, "title": "Investigation of the 2010 July\u2013August fires impact on carbon monoxide atmospheric pollution in Moscow and its outskirts, estimating of emissions", "abstract": "We investigate the air pollution in the central European part of Russia during the 2010 summer fires. The results of ground-based (Institute of Atmospheric Physics (IAP), Moscow State University (MSU), and Zvenigorod Scientific Station (ZSS)) and satellite (MOPITT, AIRS, of Terra and Aqua satellites) measurements of the total content and concentration of carbon monoxide (CO), as well as MODIS data on the spatial and temporal distribution of forest and peat fires obtained from Terra and Aqua satellites, are presented. A comparison between similar situations in 2010 and 2002 revealed the causes of higher pollution levels in 2010. The use of trajectory analysis, detailed space imagery, and model calculations made it possible to reveal the location of peat fires and their contribution to the air pollution over the Moscow megalopolis. Fireemission estimates were obtained using two independent methods.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/RS10050789", "year": 2018, "title": "Evaluation of a Bayesian Algorithm to Detect Burned Areas in the Canary", "abstract": "Burned Area (BA) is deemed as a primary variable to understand the Earth's climate system. Satellite remote sensing data have allowed for the development of various burned area detection algorithms that have been globally applied to and assessed in diverse ecosystems, ranging from tropical to boreal. In this paper, we present a Bayesian algorithm (BY-MODIS) that detects burned areas in a time series of Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2002 to 2012 of the Canary Islands' dry woodlands and forests ecoregion (Spain). Based on daily image products MODIS, MOD09GQ (250 m), and MOD11A1 (1 km), the surface spectral reflectance and the land surface temperature, respectively, 10 day composites were built using the maximum temperature criterion. Variables used in BY-MODIS were the Global Environment Monitoring Index (GEMI) and Burn Boreal Forest Index (BBFI), alongside the NIR spectral band, all of which refer to the previous year and the year the fire took place in. Reference polygons for the 14 fires exceeding 100 hectares and identified within the period under analysis were developed using both post-fire LANDSAT images and official information from the forest fires national database by the Ministry of Agriculture and Fisheries, Food and Environment of Spain (MAPAMA). The results obtained by BY-MODIS can be compared to those by official burned area products, MCD45A1 and MCD64A1. Despite that the best overall results correspond to MCD64A1, BY-MODIS proved to be an alternative for burned area mapping in the Canary Islands, a region with a great topographic complexity and diverse types of ecosystems. The total burned area detected by the BY-MODIS classifier was 64.9% of the MAPAMA reference data, and 78.6% according to data obtained from the LANDSAT images, with the lowest average commission error (11%) out of the three products and a correlation (R2) of 0.82. The Bayesian algorithm\u2014originally developed to detect burned areas in North American boreal forests using AVHRR archival data Long-Term Data Record\u2014can be successfully applied to a lower latitude forest ecosystem totally different from the boreal ecosystem and using daily time series of satellite images from MODIS with a 250 m spatial resolution, as long as a set of training areas adequately characterising the dynamics of the forest canopy affected by the fire is defined.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-22-9299-2022", "year": 2022, "title": "Radiative impacts of the Australian bushfires 20192020 Part 1: Large-scale radiative forcing", "abstract": "Abstract. As a consequence of extreme heat and drought, record-breaking wildfires developed and ravaged south-eastern Australia during the fire season 20192020. The fire strength reached its paroxysmal phase at the turn of the year 20192020. During this phase, pyrocumulonimbus clouds (pyroCb) developed and injected biomass burning aerosols and gases into the upper troposphere and lower stratosphere (UTLS). The UTLS aerosol layer was massively perturbed by these fires, with aerosol extinction increased by a factor of 3 in the visible spectral range in the Southern Hemisphere, with respect to a background atmosphere, and stratospheric aerosol optical depth reaching values as large as 0.015 in February 2020. Using the best available description of this event by observations, we estimate the radiative forcing (RF) of such perturbations of the Southern Hemispheric aerosol layer. We use offline radiative transfer modelling driven by observed information of the aerosol extinction perturbation and its spectral variability obtained from limb satellite measurements. Based on hypotheses on the absorptivity and the angular scattering properties of the aerosol layer, the regional (at three latitude bands in the Southern Hemisphere) clear-sky TOA (top-of-atmosphere) RF is found varying from small positive values to relatively large negative values (up to 2.0 W m2), and the regional clear-sky surface RF is found to be consistently negative and reaching large values (up to 4.5 W m2). We argue that clear-sky positive values are unlikely for this event, if the ageing/mixing of the biomass burning plume is mirrored by the evolution of its optical properties. Our best estimate for the area-weighted global-equivalent clear-sky RF is -0.350.21 (TOA RF) and -0.940.26 W m2 (surface RF), thus the strongest documented for a fire event and of comparable magnitude with the strongest volcanic eruptions of the post-Pinatubo era. The surplus of RF at the surface, with respect to TOA, is due to absorption within the plume that has contributed to the generation of ascending smoke vortices in the stratosphere. Highly reflective underlying surfaces, like clouds, can nevertheless swap negative to positive TOA RF, with global average RF as high as +1.0 W m2 assuming highly absorbing particles.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/DATA5020031", "year": 2020, "title": "Monthly Entomological Inoculation Rate Data for Studying the Seasonality of Malaria Transmission in Africa", "abstract": "A comprehensive literature review was conducted to create a new database of 197 field surveys of monthly malaria Entomological Inoculation Rates (EIR), a metric of malaria transmission intensity. All field studies provide data at a monthly temporal resolution and have a duration of at least one year in order to study the seasonality of the disease. For inclusion, data collection methodologies adhered to a specific standard and the location and timing of the measurements were documented. Auxiliary information on the population and hydrological setting were also included. The database includes measurements that cover West and Central Africa and the period from 1945 to 2011, and hence facilitates analysis of interannual transmission variability over broad regions.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0010273", "year": 2022, "title": "Predicting future community-level ocular Chlamydia trachomatis infection prevalence using serological, clinical, molecular, and geospatial data", "abstract": "Trachoma is an infectious disease characterized by repeated exposures to Chlamydia trachomatis (Ct) that may ultimately lead to blindness. Efficient identification of communities with high infection burden could help target more intensive control efforts. We hypothesized that IgG seroprevalence in combination with geospatial layers, machine learning, and model-based geostatistics would be able to accurately predict future community-level ocular Ct infections detected by PCR. We used measurements from 40 communities in the hyperendemic Amhara region of Ethiopia to assess this hypothesis. Median Ct infection prevalence among children 05 years old increased from 6% at enrollment, in the context of recent mass drug administration (MDA), to 29% by month 36, following three years without MDA. At baseline, correlation between seroprevalence and Ct infection was stronger among children 05 years old ( = 0.77) than children 69 years old ( = 0.48), and stronger than the correlation between active trachoma and Ct infection (0-5y = 0.56; 6-9y = 0.40). Seroprevalence was the strongest concurrent predictor of infection prevalence at month 36 among children 05 years old (cross-validated R2 = 0.75, 95% CI: 0.580.85), though predictive performance declined substantially with increasing temporal lag between predictor and outcome measurements. Geospatial variables, a spatial Gaussian process, and stacked ensemble machine learning did not meaningfully improve predictions. Serological markers among children 05 years old may be an objective tool for identifying communities with high levels of ocular Ct infections, but accurate, future prediction in the context of changing transmission remains an open challenge.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41598-021-01030-X", "year": 2021, "title": "Direct association between rainfall and non-typhoidal Salmonella bloodstream infections in hospital-admitted children in the Democratic Republic of Congo", "abstract": "Non-typhoidal Salmonella (NTS) ranks first among causes of bloodstream infection in children under five years old in the Democratic Republic of Congo and has a case fatality rate of 15%. Main host-associated risk factors are Plasmodium falciparum malaria, anemia and malnutrition. NTS transmission in sub-Saharan Africa is poorly understood. NTS bloodstream infections mostly occur during the rainy season, which may reflect seasonal variation in either environmental transmission or host susceptibility. We hypothesized that environment- and host-associated factors contribute independently to the seasonal variation in NTS bloodstream infections in children under five years old admitted to Kisantu referral hospital in 20132019. We used remotely sensed rainfall and temperature data as proxies for environmental factors and hospital data for host-associated factors. We used principal component analysis to disentangle the interrelated environment- and host-associated factors. With timeseries regression, we demonstrated a direct association between rainfall and NTS variation, independent of host-associated factors. While the latter explained 17.5% of NTS variation, rainfall explained an additional 9%. The direct association with rainfall points to environmental NTS transmission, which should be explored by environmental sampling studies. Environmental and climate change may increase NTS transmission directly or via host susceptibility, which highlights the importance of preventive public health interventions.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1126/SCIENCE.AAF5062", "year": 2016, "title": "Digital discrimination: Political bias in Internet service provision across ethnic groups", "abstract": "The global expansion of the Internet is frequently associated with increased government transparency, political rights, and democracy. However, this assumption depends on marginalized groups getting access in the first place. Here we document a strong and persistent political bias in the allocation of Internet coverage across ethnic groups worldwide. Using estimates of Internet penetration obtained through network measurements, we show that politically excluded groups suffer from significantly lower Internet penetration rates compared with those in power, an effect that cannot be explained by economic or geographic factors. Our findings underline one of the central impediments to liberation technology, which is that governments still play a key role in the allocation of the Internet and can, intentionally or not, sabotage its liberating effects.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1371/JOURNAL.PONE.0246056", "year": 2021, "title": "Epidemiological model for the inhomogeneous spatial spreading of COVID-19 and other diseases", "abstract": "We suggest a novel mathematical framework for the in-homogeneous spatial spreading of an infectious disease in human population, with particular attention to COVID-19. Common epidemiological models, e.g., the well-known susceptible-exposed-infectious-recovered (SEIR) model, implicitly assume uniform (random) encounters between the infectious and susceptible sub-populations, resulting in homogeneous spatial distributions. However, in human population, especially under different levels of mobility restrictions, this assumption is likely to fail. Splitting the geographic region under study into areal nodes, and assuming infection kinetics within nodes and between nearest-neighbor nodes, we arrive into a continuous, reaction-diffusion, spatial model. To account for COVID-19, the model includes five different sub-populations, in which the infectious sub-population is split into pre-symptomatic and symptomatic. Our model accounts for the spreading evolution of infectious population domains from initial epicenters, leading to different regimes of sub-exponential (e.g., power-law) growth. Importantly, we also account for the variable geographic density of the population, that can strongly enhance or suppress infection spreading. For instance, we show how weakly infected regions surrounding a densely populated area can cause rapid migration of the infection towards the populated area. Predicted infection heat-maps show remarkable similarity to publicly available heat-maps, e.g., from South Carolina. We further demonstrate how localized lockdown/quarantine conditions can slow down the spreading of disease from epicenters. Application of our model in different countries can provide a useful predictive tool for the authorities, in particular, for planning strong lockdown measures in localized areassuch as those underway in a few countries.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.22541/AU.162314598.80595365", "year": 2021, "title": "Mapping the risks of the spread of Peste des Petits Ruminants in the Republic of Kazakhstan", "abstract": "Peste des petits ruminants (PPR) is a viral transboundary disease of small ruminants that causes significant damage to agriculture. This disease has not been previously registered in the Republic of Kazakhstan (RK). This paper presents an assessment o", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.7554/ELIFE.69628", "year": 2022, "title": "Primate malarias as a model for cross-species parasite transmission", "abstract": "Parasites regularly switch into new host species, representing a disease burden and conservation risk to the hosts. The distribution of these parasites also gives insight into characteristics of ecological networks and genetic mechanisms of host-parasite interactions. Some parasites are shared across many species, whereas others tend to be restricted to hosts from a single species. Understanding the mechanisms producing this distribution of host specificity can enable more effective interventions and potentially identify genetic targets for vaccines or therapies. As ecological connections between human and local animal populations increase, the risk to human and wildlife health from novel parasites also increases. Which of these parasites will fizzle out and which have the potential to become widespread in humans? We consider the case of primate malarias, caused by\r\n Plasmodium\r\n parasites, to investigate the interacting ecological and evolutionary mechanisms that put human and nonhuman primates at risk for infection.\r\n Plasmodium\r\n host switching from nonhuman primates to humans led to ancient introductions of the most common malaria-causing agents in humans today, and new parasite switching is a growing threat, especially in Asia and South America. Based on a wild host-\r\n Plasmodium\r\n occurrence database, we highlight geographic areas of concern and potential areas to target further sampling. We also discuss methodological developments that will facilitate clinical and field-based interventions to improve human and wildlife health based on this eco-evolutionary perspective.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.4269/AJTMH.14-0754", "year": 2015, "title": "Investigating barriers to tuberculosis evaluation in Uganda using geographic information systems", "abstract": "Reducing geographic barriers to tuberculosis (TB) care is a priority in high-burden countries where patients frequently initiate, but do not complete, the multi-day TB evaluation process. Using routine cross-sectional study from six primary-health clinics in rural Uganda from 2009 to 2012, we explored whether geographic barriers affect completion of TB evaluation among adults with unexplained chronic cough. We measured distance from home parish to health center and calculated individual travel time using a geographic information systems technique incorporating roads, land cover, and slope, and measured its association with completion of TB evaluation. In 264,511 patient encounters, 4,640 adults (1.8%) had sputum smear microscopy ordered; 2,783 (60%) completed TB evaluation. Median travel time was 68 minutes for patients with TB examination ordered compared with 60 minutes without (P < 0.010). Travel time differed between those who did and did not complete TB evaluation at only one of six clinics, whereas distance to care did not differ at any of them. Neither distance nor travel time predicted completion of TB evaluation in rural Uganda, although limited detail in road and village maps restricted full implementation of these mapping techniques. Better data are needed on geographic barriers to access clinics offering TB services to improve TB diagnosis.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5696/2156-9614-11.29.210312", "year": 2021, "title": "Empirical Evidence for the Impact of Environmental Quality on Life Expectancy in African Countries", "abstract": "Background.\r\n Protecting the health of citizens is a central aim of sustainable development plans, due to the effect of health on social and economic development. However, studies show that environment-related diseases adversely affect the health status of a people, and this situation is worse for African countries. The Sustainable Development Goals (SDG) targets have included reducing environment-related deaths since 2015. However, there is a lack of empirical findings focused on the effects of environmental quality on life expectancy in Africa.\r\n \r\n \r\n Objectives.\r\n The present study examined the impact of environmental quality on life expectancy in 24 African countries.\r\n \r\n \r\n Methods.\r\n Time-series data ranging from 2000 to 2016 was used and the panel autoregressive distributed lag (ARDL)dynamic fixed effect (DFE) model was employed to analyze the data.\r\n \r\n \r\n Results.\r\n The results confirmed that, in the long run, improvements in environmental quality significantly increased life expectancy in the studied African countries during the study period. A unit increment in environmental performance index (EPI) and ecosystem vitality (EV) increased the life expectancy of Africans by 0.137 and 0.1417 years, respectively.\r\n \r\n \r\n Conclusions.\r\n To the best of the authors' knowledge, this is the first empirical (econometric) study using a broad measurement (indicator) of environmental quality to investigate its impact on life expectancy in African countries. The study recommends that the introduction of environmentally friendly economies (like renewable energy, land, water, and waste management), legal, socio-economic, demographic, and technological measures are essential to reduce environmental pollution and improve life expectancy in Africa.\r\n \r\n \r\n Competing Interests.\r\n The authors declare no competing financial interests.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1080/24694452.2020.1823807", "year": 2021, "title": "Empirical predictive modeling approach to quantifying social vulnerability to natural hazards", "abstract": "Conventionally, natural hazard scholars quantify social vulnerability based on social indicators to manifest the extent to which locational communities are susceptible to adverse impacts of natural hazard events and are prone to limited or delayed recoveries. They usually overlook the different geographical distributions of social vulnerability at different hazard intensities and in distinct response and recovery phases, however. In addition, conventional approaches to quantifying social vulnerability usually establish the relationship between social indicators and social vulnerability with little evidence from empirical data science. In this article, we introduce a general framework of a predictive modeling approach to quantifying social vulnerability given intensity during a response or recovery phase. We establish the relationship between social indicators and social vulnerability with an empirical statistical method and historical data on hazard effects. The new metric of social vulnerability given an intensity measure can be coupled with hazard maps for risk analysis to predict adverse impacts or poor recoveries associated with future natural hazard events. An example based on data on casualties, house damages, and peak ground accelerations of the 2015 Gorkha earthquake in Nepal and pre-event social indicators at the district level shows that the proposed approach can be applied for vulnerability quantification and risk analysis in terms of specific hazard impacts.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/AMT-14-961-2021", "year": 2021, "title": "Detection of anomalies in the UV\u2013vis reflectances from the Ozone Monitoring Instrument", "abstract": "Abstract. Various instrumental or geophysical artifacts, such as saturation, stray light or obstruction of light (either coming from the instrument or related to solar eclipses), negatively impact satellite measured ultraviolet and visible Earthshine radiance spectra and downstream retrievals of atmospheric and surface properties derived from these spectra. In addition, excessive noise such as from cosmic-ray impacts, prevalent within the South Atlantic Anomaly, can also degrade satellite radiance measurements. Saturation specifically pertains to observations of very bright surfaces such as sunglint over open water or thick clouds. When saturation occurs, additional photoelectric charge generated at the saturated pixel may overflow to pixels adjacent to a saturated area and be reflected as a distorted image in the final sensor output. When these effects cannot be corrected to an acceptable level for science-quality retrievals, flagging of the affected pixels is indicated. Here, we introduce a straightforward detection method that is based on the correlation, r, between the observed Earthshine radiance and solar irradiance spectra over a 10 nm spectral range; our decorrelation index (DI for brevity) is simply defined as a DI of 1r. DI increases with anomalous additive effects or excessive noise in either radiances, the most likely cause in data from the Ozone Monitoring Instrument (OMI), or irradiances. DI is relatively straightforward to use and interpret and can be computed for different wavelength intervals. We developed a set of DIs for two spectral channels of the OMI, a hyperspectral pushbroom imaging spectrometer. For each OMI spatial measurement, we define 14 wavelength-dependent DIs within the OMI visible channel (350498 nm) and six DIs in its ultraviolet 2 (UV2) channel (310370 nm). As defined, DIs reflect a continuous range of deviations of observed spectra from the reference irradiance spectrum that are complementary to the binary saturation possibility warning (SPW) flags currently provided for each individual spectral or spatial pixel in the OMI radiance data set. Smaller values of DI are also caused by a number of geophysical factors; this allows one to obtain interesting physical results on the global distribution of spectral variations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.4081/GH.2019.676", "year": 2019, "title": "Predicting malaria cases using remotely sensed environmental variables in Nkomazi, South Africa", "abstract": "There has been a conspicuous increase in malaria cases since 2016/2017 over the three malaria-endemic provinces of South Africa. This increase has been linked to climatic and environmental factors. In the absence of adequate traditional environmental/climatic data covering ideal spatial and temporal extent for a reliable warning system, remotely sensed data are useful for the investigation of the relationship with, and the prediction of, malaria cases. Monthly environmental variables such as the normalised difference vegetation index (NDVI), the enhanced vegetation index (EVI), the normalised difference water index (NDWI), the land surface temperature for night (LSTN) and day (LSTD), and rainfall were derived and evaluated using seasonal autoregressive integrated moving average (SARIMA) models with different lag periods. Predictions were made for the last 56 months of the time series and were compared to the observed malaria cases from January 2013 to August 2017. All these factors were found to be statistically significant in predicting malaria transmission at a 2-months lag period except for LSTD which impact the number of malaria cases negatively. Rainfall showed the highest association at the two-month lag time (r=0.74; P<0.001), followed by EVI (r=0.69; P<0.001), NDVI (r=0.65; P<0.001), NDWI (r=0.63; P<0.001) and LSTN (r=0.60; P<0.001). SARIMA without environmental variables had an adjusted R2 of 0.41, while SARIMA with total monthly rainfall, EVI, NDVI, NDWI and LSTN were able to explain about 65% of the variation in malaria cases. The prediction indicated a general increase in malaria cases, predicting about 711 against 648 observed malaria cases. The development of a predictive early warning system is imperative for effective malaria control, prevention of outbreaks and its subsequent elimination in the region.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41598-021-89576-8", "year": 2021, "title": "Predicting distribution of malaria vector larval habitats in Ethiopia by integrating distributed hydrologic modeling with remotely sensed data", "abstract": "Larval source management has gained renewed interest as a malaria control strategy in Africa but the widespread and transient nature of larval breeding sites poses a challenge to its implementation. To address this problem, we propose combining an integrated high resolution (50 m) distributed hydrological model and remotely sensed data to simulate potential malaria vector aquatic habitats. The novelty of our approach lies in its consideration of irrigation practices and its ability to resolve complex ponding processes that contribute to potential larval habitats. The simulation was performed for the year of 2018 using ParFlow-Common Land Model (CLM) in a sugarcane plantation in the Oromia region, Ethiopia to examine the effects of rainfall and irrigation. The model was calibrated using field observations of larval habitats to successfully predict ponding at all surveyed locations from the validation dataset. Results show that without irrigation, at least half of the area inside the farms had a 40% probability of potential larval habitat occurrence. With irrigation, the probability increased to 56%. Irrigation dampened the seasonality of the potential larval habitats such that the peak larval habitat occurrence window during the rainy season was extended into the dry season. Furthermore, the stability of the habitats was prolonged, with a significant shift from semi-permanent to permanent habitats. Our study provides a hydrological perspective on the impact of environmental modification on malaria vector ecology, which can potentially inform malaria control strategies through better water management.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S10661-019-7414-3", "year": 2019, "title": "Development and validation of improved PM2. 5 models for public health applications using remotely sensed aerosol and meteorological data", "abstract": "In this study, Moderate Resolution Imaging Spectrometer (MODIS) satellite measurements of aerosol optical depth (AOD) from different retrieval algorithms have been correlated with ground measurements of fine particulate matter less than 2.5 m (PM2.5). Several MODIS AOD products from different satellites (Aqua vs. Terra), retrieval algorithms (Dark Target vs. Deep Blue), collections (5.1 vs. 6), and spatial resolutions (10 km vs. 3 km) for cities in the Western, Midwestern, and Southeastern USA have been evaluated. We developed and validated PM2.5 prediction models using remotely sensed AOD data. These models were further improved by incorporating meteorological variables (temperature, relative humidity, precipitation, wind gust, and wind direction) from the North American Land Data Assimilation System Phase 2 (NLDAS-2). Adding these meteorological data significantly improved the simulation quality of all the PM2.5 models, especially in the Western USA. Temperature, relative humidity, and wind gust were significant meteorological variables throughout the year in the Western USA. Wind speed was the most significant meteorological variable for the cold season while for the warm season, temperature was the most prominent one in the Midwestern and Southeastern USA. Using this satellite-derived PM2.5 data can improve the spatial coverage, especially in areas where PM2.5 ground monitors are lacking, and studying the connections between PM2.5 and public health concerns including respiratory and cardiovascular diseases in the USA can be further advanced.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1093/JME/TJX163", "year": 2017, "title": "Modeling the Environmental Suitability for Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the Contiguous United States", "abstract": "Abstract\r\n The mosquitoes Aedes (Stegomyia) aegypti (L.)(Diptera:Culicidae) and Ae. (Stegomyia) albopictus (Skuse) (Diptera:Culicidae) transmit dengue, chikungunya, and Zika viruses and represent a growing public health threat in parts of the United States where they are established. To complement existing mosquito presence records based on discontinuous, non-systematic surveillance efforts, we developed county-scale environmental suitability maps for both species using maximum entropy modeling to fit climatic variables to county presence records from 19602016 in the contiguous United States. The predictive models for Ae. aegypti and Ae. albopictus had an overall accuracy of 0.84 and 0.85, respectively. Cumulative growing degree days (GDDs) during the winter months, an indicator of overall warmth, was the most important predictive variable for both species and was positively associated with environmental suitability. The number (percentage) of counties classified as environmentally suitable, based on models with 90 or 99% sensitivity, ranged from 1,443 (46%) to 2,209 (71%) for Ae. aegypti and from 1,726 (55%) to 2,329 (75%) for Ae. albopictus. Increasing model sensitivity results in more counties classified as suitable, at least for summer survival, from which there are no mosquito records. We anticipate that Ae. aegypti and Ae. albopictus will be found more commonly in counties classified as suitable based on the lower 90% sensitivity threshold compared with the higher 99% threshold. Counties predicted suitable with 90% sensitivity should therefore be a top priority for expanded mosquito surveillance efforts while still keeping in mind that Ae. aegypti and Ae. albopictus may be introduced, via accidental transport of eggs or immatures, and potentially proliferate during the warmest part of the year anywhere within the geographic areas delineated by the 99% sensitivity model.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.SCITOTENV.2020.139297", "year": 2020, "title": "The dark cloud with a silver lining: Assessing the impact of the SARS COVID-19 pandemic on the global environment", "abstract": "The Severe Acute Respiratory Syndrome-Coronavirus Disease 2019 (COVID-19) pandemic caused by a novel coronavirus known as SARS-CoV-2 has caused tremendous suffering and huge economic losses. We hypothesized that extreme measures of partial-to-total shutdown might have influenced the quality of the global environment because of decreased emissions of atmospheric pollutants. We tested this hypothesis using satellite imagery, climatic datasets (temperature, and absolute humidity), and COVID-19 cases available in the public domain. While the majority of the cases were recorded from Western countries, where mortality rates were strongly positively correlated with age, the number of cases in tropical regions was relatively lower than European and North American regions, possibly attributed to faster human-to-human transmission. There was a substantial reduction in the level of nitrogen dioxide (NO2: 0.00002 mol m2), a low reduction in CO (<0.03 mol m2), and a low-to-moderate reduction in Aerosol Optical Depth (AOD: ~0.10.2) in the major hotspots of COVID-19 outbreak during FebruaryMarch 2020, which may be attributed to the mass lockdowns. Our study projects an increasing coverage of high COVID-19 hazard at absolute humidity levels ranging from 4 to 9 g m3 across a large part of the globe during AprilJuly 2020 due to a high prospective meteorological suitability for COVID-19 spread. Our findings suggest that there is ample scope for restoring the global environment from the ill-effects of anthropogenic activities through temporary shutdown measures.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ANI11051208", "year": 2021, "title": "Modelling the Spatial Distribution of ASF-Positive wild boar carcasses in South Korea using 2019\u20132020 national surveillance data", "abstract": "In September 2019, African swine fever (ASF) was reported in South Korea for the first time. Since then, more than 651 ASF cases in wild boars and 14 farm outbreaks have been notified in the country. Despite the efforts to eradicate ASF among wild boar populations, the number of reported ASF-positive wild boar carcasses have increased recently. The purpose of this study was to characterize the spatial distribution of ASF-positive wild boar carcasses to identify the risk factors associated with the presence and number of ASF-positive wild boar carcasses in the affected areas. Because surveillance efforts have substantially increased in early 2020, we divided the study into two periods (2 October 2019 to 19 January 2020, and 19 January to 28 April 2020) based on the number of reported cases and aggregated the number of reported ASF-positive carcasses into a regular grid of hexagons of 3-km diameter. To account for imperfect detection of positive carcasses, we adjusted spatial zero-inflated Poisson regression models to the number of ASF-positive wild boar carcasses per hexagon. During the first study period, proximity to North Korea was identified as the major risk factor for the presence of African swine fever virus. In addition, there were more positive carcasses reported in affected hexagons with high habitat suitability for wild boars, low heat load index (HLI), and high human density. During the second study period, proximity to an ASF-positive carcass reported during the first period was the only significant risk factor for the presence of ASF-positive carcasses. Additionally, low HLI and elevation were associated with an increased number of ASF-positive carcasses reported in the affected hexagons. Although the proportion of ASF-affected hexagons increased from 0.06 (95% credible interval (CrI): 0.050.07) to 0.09 (95% CrI: 0.080.10), the probability of reporting at least one positive carcass in ASF-affected hexagons increased from 0.49 (95% CrI: 0.410.57) to 0.73 (95% CrI: 0.660.81) between the two study periods. These results can be used to further advance risk-based surveillance strategies in the Republic of Korea.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PONE.0238323", "year": 2020, "title": "Assessment of effectiveness of DAMaN: a malaria intervention program initiated by Government of Odisha, India", "abstract": "India, a persistently significant contributor to the global malaria burden, rolled out several anti-malaria interventions at the national and state level to control and recently, to eliminate the disease. Odisha, the eastern Indian state with the highest malaria burden experienced substantial gains shown by various anti-malaria initiatives implemented under the National Vector-borne Disease Control Programme (NVBDCP). However, recalcitrant high-transmission pockets of malaria persist in hard-to-reach stretches of the state, characterised by limited access to routine malaria surveillance and the forested hilly topography favouring unbridled vector breeding. The prevalence of asymptomatic malaria in such pockets serves as perpetual malaria reservoir, thus hindering its elimination. Therefore, a project with the acronym DAMaN was initiated since 2017 by state NVBDCP, targeting locally identified high endemic pockets in 23 districts. DAMaN comprised biennial mass screening and treatment, provisioning of long-lasting insecticidal net (LLIN) and behavioural change communication. Subsequently, to inform policy, assessment of DAMaN was conceived that aims to estimate the coverage of the various components of the project; the prevalence of malaria, even at sub-patent level especially among pregnant/lactating women and children; and its impact on malaria incidence. A survey of DAMaN beneficiaries will measure coverage; and knowledge and practices related to LLIN; along with collection of blood specimens from a probability sample. A multi-stage stratified clustered sample of 2228 households (~33% having pregnant/lactating women) will be selected from 6 DAMaN districts. Routine DAMaN project data (20172018) and NVBDCP data (20132018) will be extracted. Rapid Diagnostic Test, Polymerase Chain Reaction and blood smear microscopy will be conducted to detect malarial parasitemia. In addition to measuring DAMaNs coverage and malarial prevalence in DAMaN pockets, its impact will be estimated using pre-post differences and Interrupted Time Series analysis using 2017 as the inflection point. The assessment may help to validate the unique strategies employed by DAMaN.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PONE.0268995", "year": 2022, "title": "Spatio-temporal spread of COVID-19: Comparison of the inhomogeneous SEPIR model and data from South Carolina", "abstract": "During the COVID-19 pandemic authorities have been striving to obtain reliable predictions for the spreading dynamics of the disease. We recently developed a multi-sub-populations (multi-compartments: susceptible, exposed, pre-symptomatic, infectious, recovered) model, that accounts for the spatial in-homogeneous spreading of the infection and shown, for a variety of examples, how the epidemic curves are highly sensitive to location of epicenters, non-uniform population density, and local restrictions. In the present work we test our model against real-life data from South Carolina during the period May 22 to July 22 (2020). During this period, minimal restrictions have been employed, which allowed us to assume that the local basic reproduction number is constant in time. We account for the non-uniform population density in South Carolina using data from NASAs Socioeconomic Data and Applications Center (SEDAC), and predict the evolution of infection heat-maps during the studied period. Comparing the predicted heat-maps with those observed, we find high qualitative resemblance. Moreover, the Pearsons correlation coefficient is relatively high thus validating our model against real-world data. We conclude that the model accounts for the major effects controlling spatial in-homogeneous spreading of the disease. Inclusion of additional sub-populations (compartments), in the spirit of several recently developed models for COVID-19, can be easily performed within our mathematical framework.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/IJERPH19127262", "year": 2022, "title": "Coccidioidomycosis (Valley Fever), Soil Moisture, and El Nino Southern Oscillation in California and Arizona", "abstract": "The soil-borne fungal disease coccidioidomycosis (Valley fever) is prevalent across the southwestern United States (US). Previous studies have suggested that the occurrence of this infection is associated with anomalously wet or dry soil moisture states described by the grow and blow hypothesis. The growth of coccidioidomycosis is favored by moist conditions both at the surface and in the root zone. A statistical analysis identified two areas in Arizona and central California, with a moderate-to-high number of coccidioidomycosis cases. A Wavelet Transform Coherence (WTC) analysis between El Nino Southern Oscillation (ENSO), coccidioidomycosis cases, surface soil moisture (SSM; 0 to 5 cm) from European Space Agency-Climate Change Initiative (ESA-CCI), and shallow root zone soil moisture (RZSM; 0 to 40 cm depth) from Soil MERGE (SMERGE) was executed for twenty-four CA and AZ counties. In AZ, only SSM was modulated by ENSO. When case values were adjusted for overreporting between 2009 to 2012, a moderate but significant connection between ENSO and cases was observed at a short periodicity (2.1 years). In central CA, SSM, RZSM, and cases all had a significant link to ENSO at longer periodicities (5-to-7 years). This study provides an example of how oceanic-atmospheric teleconnections can impact human health.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ENVRES.2020.110052", "year": 2020, "title": "An ecological analysis of long-term exposure to PM2.5 and incidence of", "abstract": "Background. Ambient fine particulate matter (PM2.5) is associated with a wide range of acute and chronic health effects, including increased risk of respiratory infection. However, evidence specifically related to novel coronavirus disease (COVID-19) is limited.

Methods. COVID-19 case counts for 111 Canadian health regions were obtained from the COVID-19 Canada Open Data portal. Annual PM2.5 data for 2000-2016 were estimated from a national exposure surface based on remote sensing, chemical transport modelling and ground observations, and minimum and maximum temperature data for 2000-2015 were based on a national interpolated surface derived from thin-plate smoothing splines. Population counts and sociodemographic data by health region were obtained from the 2016 census, and health data (self-rated health and prevalence of smoking, obesity, and selected chronic diseases) by health region, were obtained from the Canadian Community Health Survey. Data on total number of COVID-19 tests and changes in mobility comparing post-vs. pre-introduction of social distancing measures were available by province. Data were analyzed using negative binomial regression models.

Results. After controlling for province, temperature, demographic and health characteristics and days since peak incidence by health region, long-term PM2.5 exposure exhibited a positive association with COVID-19 incidence (incidence rate ratio 1.07, 95% confidence interval 0.97-1.18 per \u03bcg/m3). This association was larger in magnitude and statistically significant in analyses excluding provinces that reported cases only for aggregated health regions, excluding health regions with less than median population density, and restricted to the most highly affected provinces (Quebec and Ontario).

Conclusions. We observed a positive association between COVID-19 incidence and long-term PM2.5 exposure in Canadian health regions. The association was larger in magnitude and statistically significant in more highly affected health regions and those with potentially less exposure measurement error. While our results generate hypotheses for further testing, they should be interpreted with caution and require further examination using study designs less prone to bias.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1093/INFDIS/JIX496", "year": 2017, "title": "A Persistent Hotspot of Schistosoma mansoni Infection in a Five-Year Randomized Trial of Praziquantel Preventative Chemotherapy Strategies", "abstract": "Persistent hotspots have been described after mass drug administration (MDA) for the control of schistosomiasis, but they have not been studied during the course of a multiyear MDA program.In data from a 5-year study of school-based and village-wide preventive chemotherapy strategies for Schistosoma mansoni, spatial scan statistics were used to find infection hotspots in 3 populations: 5- to 8-year-olds, 9- to 12-year-olds, and adults. Negative binomial regression was used to analyze changes from baseline, and receiver operating characteristic analyses were used to predict which villages would reach prevalence and intensity endpoints.We identified a persistent hotspot, not associated with study arm, where S. mansoni infection prevalence and intensity did not decrease as much as in villages outside the hotspot. Significant differences from baseline were realized after 1 year of MDA: we did not identify factors that moderated this relationship. Villages meeting specified endpoints at year 5 were predicted from prior year data with moderately high sensitivity and specificity.The MDA strategies were less effective at reducing prevalence and intensity in the hotspot compared with other villages. Villages that reached year 5 endpoints could be detected earlier, which may provide the opportunity to amend intervention strategies.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ENVPOL.2019.06.074", "year": 2019, "title": "Compilation and spatio-temporal analysis of publicly available total solar and UV irradiance data in the contiguous United States", "abstract": "Skin cancer is the most common type of cancer in the United States, the majority of which is caused by overexposure to ultraviolet (UV) irradiance, which is one component of sunlight. National Environmental Public Health Tracking Program at CDC has collaborated with partners to develop and disseminate county-level daily UV irradiance (20052015) and total solar irradiance (19912012) data for the contiguous United States. UV irradiance dataset was derived from the Ozone Monitoring Instrument (OMI), and solar irradiance was extracted from National Solar Radiation Data Base (NSRDB) and SolarAnywhere data. Firstly, we produced daily population-weighted UV and solar irradiance datasets at the county level. Then the spatial distributions and long-term trends of UV irradiance, solar irradiance and the ratio of UV irradiance to solar irradiance were analyzed. The national average values across all years are 4300 Wh/m2, 2700 J/m2 and 130 mW/m2 for global horizontal irradiance (GHI), erythemally weighted daily dose of UV irradiance (EDD) and erythemally weighted UV irradiance at local solar noon time (EDR), respectively. Solar, UV irradiances and the ratio of UV to solar irradiance all increased toward the South and in some areas with high altitude, suggesting that using solar irradiance as indicator of UV irradiance in studies covering large geographic regions may bias the true pattern of UV exposure. National annual average daily solar and UV irradiances increased significantly over the years by about 0.3% and 0.5% per year, respectively. Both datasets are available to the public through CDC's Tracking network. The UV irradiance dataset is currently the only publicly-available, spatially-resolved, and long-term UV irradiance dataset covering the contiguous United States. These datasets help us understand the spatial distributions and temporal trends of solar and UV irradiances, and allow for improved characterization of UV and sunlight exposure in future studies.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41586-019-1878-8", "year": 2020, "title": "Mapping child growth failure across low-and middle-income countries", "abstract": "Childhood malnutrition is associated with high morbidity and mortality globally1. Undernourished children are more likely to experience cognitive, physical, and metabolic developmental impairments that can lead to later cardiovascular disease, reduced intellectual ability and school attainment, and reduced economic productivity in adulthood2. Child growth failure (CGF), expressed as stunting, wasting, and underweight in children under five years of age (059 months), is a specific subset of undernutrition characterized by insufficient height or weight against age-specific growth reference standards35. The prevalence of stunting, wasting, or underweight in children under five is the proportion of children with a height-for-age, weight-for-height, or weight-for-age z-score, respectively, that is more than two standard deviations below the World Health Organizations median growth reference standards for a healthy population6. Subnational estimates of CGF report substantial heterogeneity within countries, but are available primarily at the first administrative level (for example, states or provinces)7; the uneven geographical distribution of CGF has motivated further calls for assessments that can match the local scale of many public health programmes8. Building from our previous work mapping CGF in Africa9, here we provide the first, to our knowledge, mapped high-spatial-resolution estimates of CGF indicators from 2000 to 2017 across 105 low- and middle-income countries (LMICs), where 99% of affected children live1, aggregated to policy-relevant first and second (for example, districts or counties) administrative-level units and national levels. Despite remarkable declines over the study period, many LMICs remain far from the ambitious World Health Organization Global Nutrition Targets to reduce stunting by 40% and wasting to less than 5% by 2025. Large disparities in prevalence and progress exist across and within countries; our maps identify high-prevalence areas even within nations otherwise succeeding in reducing overall CGF prevalence. By highlighting where the highest-need populations reside, these geospatial estimates can support policy-makers in planning interventions that are adapted locally and in efficiently directing resources towards reducing CGF and its health implications.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0010155", "year": 2022, "title": "The effect of livestock density on Trypanosoma brucei gambiense and T. b. rhodesiense: A causal inference-based approach", "abstract": "Domestic and wild animals are important reservoirs of the rhodesiense form of human African trypanosomiasis (rHAT), however quantification of this effect offers utility for deploying non-medical control activities, and anticipating their success when wildlife are excluded. Further, the uncertain role of animal reservoirsparticularly pigsthreatens elimination of transmission (EOT) targets set for the gambiense form (gHAT). Using a new time series of high-resolution cattle and pig density maps, HAT surveillance data collated by the WHO Atlas of HAT, and methods drawn from causal inference and spatial epidemiology, we conducted a retrospective ecological cohort study in Uganda, Malawi, Democratic Republic of the Congo (DRC) and South Sudan to estimate the effect of cattle and pig density on HAT risk. For rHAT, we found a positive effect for cattle (RR 1.61, 95% CI 0.90, 2.99) and pigs (RR 2.07, 95% CI 1.15, 2.75) in Uganda, and a negative effect for cattle (RR 0.88, 95% CI 0.71, 1.10) and pigs (RR 0.42, 95% CI 0.23, 0.67) in Malawi. For gHAT we found a negative effect for cattle in Uganda (RR 0.88, 95% CI 0.50, 1.77) and South Sudan (RR 0.63, 95% CI 0.54, 0.77) but a positive effect in DRC (1.17, 95% CI 1.04, 1.32). For pigs, we found a positive gHAT effect in both Uganda (RR 2.02, 95% CI 0.87, 3.94) and DRC (RR 1.23, 95% CI 1.10, 1.37), and a negative association in South Sudan (RR 0.66, 95% CI 0.50, 0.98). These effects did not reach significance for the cattle-rHAT effect in Uganda or Malawi, or the cattle-gHAT and pig-gHAT effects in Uganda. While ecological bias may drive the findings in South Sudan, estimated E-values and simulation studies suggest unmeasured confounding and underreporting are unlikely to explain our findings in Malawi, Uganda, and DRC. Our results suggest cattle and pigs may be important reservoirs of rHAT in Uganda but not Malawi, and that pigsand possibly cattlemay be gHAT reservoirs.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1109/TGRS.2017.2748031", "year": 2018, "title": "Estimating error covariance and correlation region in UV irradiance data fusion by combining TOMS-OMI and UVMRP ground observations", "abstract": "Surface ultraviolet (UV) observations can be obtained from satellite or ground observations. This paper uses one data fusion technique (similar to Kalman filter) to combine the advantages from both sources of observations, aiming at achieving a better estimate of surface UV. In this paper, new mathematical methods and algorithms were developed to estimate the error covariance and correlation region, which are the most important components in this data fusion technique. This technique was applied to the satellite data from the Total Ozone Mapping Spectrometer (TOMS)-Ozone Monitoring Instrument (OMI) combined with ground measurements from UV-B Monitoring and Research Program (UVMRP) within the region of continental U.S. from 2005 to 2015. Numerical experiments showed that the technique is effective, and TOMS-OMI data were improved by combining UVMRP data. In addition, the innovative ensemble-based method is generic and can be applied to other fields for data fusion/assimilation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/ETC.4181", "year": 2018, "title": "Predicting risks from downthedrain chemicals in a developing country: Mexico and linear alkylbenzene sulfonate as a case study", "abstract": "AbstractIt is recognized that the amount of natural dilution available can make a significant difference in the exposure and risk assessment of chemicals that emanate from wastewater treatment plants (WWTPs). However, data availability is a common limiting factor in exposure assessments for emerging markets. In the present study, we used a novel approach to derive dilution factors for the receiving waters within 5 km of wastewater discharge points in Mexico by combining locally measured river volumes, ecoregion categorization, data on WWTP capacity, and global river network models. Distributions of wastewater effluent into receiving stream dilution factors were developed for the entire country and organized by ecoregion type to explore spatial differences. The distribution of dilution factors in Mexico ranged from >1000 in tropical and temperate ecoregions to 1 in desert ecoregions. To demonstrate its utility, dilution factors were used to develop a probabilistic model to explore the potential ecological risks of the highvolume surfactant linear alkylbenzene sulfonate (LAS), commonly used in downthedrain cleaning products. The predicted LAS river exposure values were below the predicted noeffect concentration in all regions. The methodology developed for Mexico can be used to derive refined exposure assessments in other countries with emerging markets throughout the world, resulting in more realistic risk assessments. Environ Toxicol Chem 2018;37:24752486. 2018 SETAC", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.3390/RS12121965", "year": 2020, "title": "Suitability of the MODIS-NDVI Time-Series for a Posteriori Evaluation of the Citrus Tristeza Virus Epidemic", "abstract": "The technological advances of remote sensing (RS) have allowed its use in a number of fields of application including plant disease depiction. In this study, an RS approach based on an 18-year (i.e., 20012018) time-series analysis of Normalized Difference Vegetation Index (NDVI) data, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and processed with TIMESAT free software, was applied in Sicily (insular Italy). The RS approach was carried out in four orchards infected by Citrus tristeza virus (CTV) at different temporal stages and characterized by heterogeneous conditions (e.g., elevation, location, plant age). The temporal analysis allowed the identification of specific metrics of the NDVI time-series at the selected sites during the study period. The most reliable parameter which was able to identify the temporal evolution of CTV syndrome and the impact of operational management practices was the Base value (i.e., average NDVI during the growing seasons, which reached R2 values up to 0.88), showing good relationships with Peak value, Small integrated value and Amplitude, with R2 values of 0.63, 0.70 and 0.75, respectively. The approach herein developed is valid to be transferred to regional agencies involved in and/or in charge of the management of plant diseases, especially if it is integrated with ground-based early detection methods or high-resolution RS approaches, in the case of quarantine plant pathogens requiring control measures at large-scale level.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41370-018-0105-2", "year": 2018, "title": "Suitability of gridded climate datasets for use in environmental epidemiology", "abstract": "Epidemiologic analyses of the health effects of meteorological exposures typically rely on observations from the nearest weather station to assess exposure for geographically diverse populations. Gridded climate datasets (GCD) provide spatially resolved weather data that may offer improved exposure estimates, but have not been systematically validated for use in epidemiologic evaluations. As a validation, we linearly regressed daily weather estimates from two GCDs, PRISM and Daymet, to observations from a sample of weather stations across the conterminous United States and compared spatially resolved, population-weighted county average temperatures and heat indices from PRISM to single-pixel PRISM values at the weather stations to identify differences. We found that both Daymet and PRISM accurately estimate ambient temperature and mean heat index at sampled weather stations, but PRISM outperforms Daymet for assessments of humidity and maximum daily heat index. Moreover, spatially-resolved exposure estimates differ from point-based assessments, but with substantial inter-county heterogeneity. We conclude that GCDs offer a potentially useful approach to exposure assessment of meteorological variables that may, in some locations, reduce exposure measurement error, as well as permit assessment of populations distributed far from weather stations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1038/S41467-021-21496-7", "year": 2021, "title": "Climate predicts geographic and temporal variation in mosquito-borne disease dynamics on two continents", "abstract": "Climate drives population dynamics through multiple mechanisms, which can lead to seemingly context-dependent effects of climate on natural populations. For climate-sensitive diseases, such as dengue, chikungunya, and Zika, climate appears to have opposing effects in different contexts. Here we show that a model, parameterized with laboratory measured climate-driven mosquito physiology, captures three key epidemic characteristics across ecologically and culturally distinct settings in Ecuador and Kenya: the number, timing, and duration of outbreaks. The model generates a range of disease dynamics consistent with observed Aedes aegypti abundances and laboratory-confirmed arboviral incidence with variable accuracy (2885% for vectors, 4488% for incidence). The model predicted vector dynamics better in sites with a smaller proportion of young children in the population, lower mean temperature, and homes with piped water and made of cement. Models with limited calibration that robustly capture climate-virus relationships can help guide intervention efforts and climate change disease projections.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/978-981-19-1324-2_4", "year": 2022, "title": "Effect of Geospatial Weather Features on COVID-19 Spread in Maharashtra State Using Machine Learning", "abstract": "COVID-19 has become the most pestilential disease that has severely spread all over the world with several variants where the second wave of COVID-19 (2.0) has devastated India and worldwide most. This research is focused to assess the association among COVID-19 confirmed cases, weather features, mainly temperature (T), relative humidity (RH), and precipitation (P). The most affected populated state Maharashtra is considered as the research area for which we have collected newly confirmed COVID-19 cases and weather data that were considered for the first variant (COVID-19 1.0) and second variant (COVID-19 2.0) from March, 2020 to June, 2021. In this work, regression techniques have been applied to investigate daily new confirmed COVID-19 cases where the decision tree predicts the most accurate results. Outcomes demonstrate that temperature and relative humidity played an important role in this forecasting scheme as relative humidity is negative, and the temperature has positive correlation with COVID-19 affected cases. This application could be used for displaying and anticipating confirmed cases every day.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/IJERPH18031077", "year": 2021, "title": "Spatio-Temporal Dynamics of Plasmodium falciparum and Plasmodium vivax", "abstract": "Aims: This study examines the dynamics of malaria as influenced by meteorological factors in French Guiana from 2005 to 2019. It explores spatial hotspots of malaria transmission and aims to determine the factors associated with variation of hotspots with time. Methods: Data for individual malaria cases came from the surveillance system of the Delocalized Centers for Prevention and Care (CDPS) (n = 17) from 20052019. Meteorological data was acquired from the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) database. The BoxJenkins autoregressive integrated moving average (ARIMA) model tested stationarity of the time series, and the impact of meteorological indices (issued from principal component analysisPCA) on malaria incidence was determined with a general additive model. Hotspot characterization was performed using spatial scan statistics. Results: The current sample includes 7050 eligible Plasmodium vivax (n = 4111) and Plasmodium falciparum (n = 2939) cases from health centers across French Guiana. The first and second PCA-derived meteorological components (maximum/minimum temperature/minimum humidity and maximum humidity, respectively) were significantly negatively correlated with total malaria incidence with a lag of one week and 10 days, respectively. Overall malaria incidence decreased across the time series until 2017 when incidence began to trend upwards. Hotspot characterization revealed a few health centers that exhibited spatial stability across the entire time series: Saint Georges de lOyapock and Antecume Pata for P. falciparum, and Saint Georges de lOyapock, Antecume Pata, Regina and Camopi for P. vivax. Conclusions: This study highlighted changing malaria incidence in French Guiana and the influences of meteorological factors on transmission. Many health centers showed spatial stability in transmission, albeit not temporal. Knowledge of the areas of high transmission as well as how and why transmission has changed over time can inform strategies to reduce the transmission of malaria in French Guiana. Hotspots should be further investigated to understand other influences on local transmission, which will help to facilitate elimination.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1186/S12940-021-00733-Y", "year": 2021, "title": "Acute associations between heatwaves and preterm and early-term birth in 50 US metropolitan areas: a matched case-control study", "abstract": "The effect of heatwaves on adverse birth outcomes is not well understood and may vary by how heatwaves are defined. The study aims to examine acute associations between various heatwave definitions and preterm and early-term birth.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1002/ECS2.4267", "year": 2022, "title": "Landscape dynamics of a vectorborne disease in the western\n US\n : How vectorhabitat relationships inform disease hotspots", "abstract": "Vesicular stomatitis (VS) is a vector\u2011borne viral disease that causes lesions in livestock, premises, county and state quarantines, and important economic losses. We investigated vector\u2013habitat characteristics for vectors associated with VS in regions of recurrent disease within the western United States (US) that consistently lead to the environment where vector, host, and pathogen populations intersect to enable pathogen transmission. We analyzed the habitats of previously identified insect vectors, including black flies (BFs) (Simulium vittatum complex), biting midges (BMs) (Culicoides variipennis complex, which includes Culicoides sonorensis), and sand flies (SFs) (Lutzomyia shannoni) in six regions of interest (ROIs) containing hotspots of VS ranging from Texas (TX) to Wyoming. This analysis broadened the understanding of (1) how regions of reoccurring VS differ from the broader western US, (2) how geographically separated regions and hotspots are similar across time, and (3) how vector\u2013environment habitat a priori knowledge relates to observed hotspots. Analysis of watershed factors (livestock densities, land\u2011cover proportions, stream and lake densities, and irrigation methods) indicated a complex system separating areas with high, recurring VS from the broader western US. Although no single characteristic separated the six ROIs from other areas, we found two distinct emerging groups (northern ROI and TX). Hotspots, estimated from monthly VS concentrations, evolved northward throughout the year and most hotspots were closer to flowing water and agricultural land than the broader ROI. All ROIs contained environmental conditions suitable for multiple vectors at some point in the year, but BFs had the highest suitability scores, whereas BM scores were lower and varied annually with higher suitability in summer. SFs had the lowest suitability score in all ROIs, consistent with their low likelihood of being vectors. BM habitat patches were often orders of magnitude smaller than BF patches, and hotspot patches reinforce the likelihood that BF may be the most critical vector in northern ROI, whereas both BM and BF have similar likelihood in southern ROI. Given limited existing vector data, this analysis provides an alternate pathway for using habitat information to associate likely vectors responsible for transmission. Results could support early warning and mitigation efforts to reduce the incidence of VS.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1111/GCB.15384", "year": 2021, "title": "Warming temperatures could expose more than 1.3\u00a0billion new people to Zika virus risk by 2050", "abstract": "AbstractIn the aftermath of the 2015 pandemic of Zika virus (ZIKV), concerns over links between climate change and emerging arboviruses have become more pressing. Given the potential that much of the world might remain at risk from the virus, we used a previously established temperaturedependent transmission model for ZIKV to project climate change impacts on transmission suitability risk by midcentury (a generation into the future). Based on these model predictions, in the worstcase scenario, over 1.3 billion new people could face suitable transmission temperatures for ZIKV by 2050. The next generation will face substantially increased ZIKV transmission temperature suitability in North America and Europe, where naive populations might be particularly vulnerable. Mitigating climate change even to moderate emissions scenarios could significantly reduce global expansion of climates suitable for ZIKV transmission, potentially protecting around 200 million people. Given these suitability risk projections, we suggest an increased priority on research establishing the immune history of vulnerable populations, modeling when and where the next ZIKV outbreak might occur, evaluating the efficacy of conventional and novel intervention measures, and increasing surveillance efforts to prevent further expansion of ZIKV.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41598-018-27631-7", "year": 2018, "title": "Global patterns of human and livestock respiration", "abstract": "Carbon emissions from human and animals has been neglected by previous studies in estimating the carbon cycle of ecosystem. This study first estimates the spatial-temporal patterns of carbon emissions density from human and livestock respiration among countries around the world from 19602014. Then we simulate the soil heterotrophic respiration (Rh) to analyze the contribution of human and livestock respiration to total heterotrophic respiration of global ecosystem. Our results show that the respiration of human and livestock respectively contribute more than 1% of the total carbon output from heterotrophic respiration in most countries and affect more than 5% in almost half of the countries. Moreover, the effect of livestock respiration is slightly greater than that of human beings. Therefore, the estimation of heterotrophic respiration should not only consider Rh in these countries, human and livestock respiration are equally important in the research on regional carbon budget.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1002/PS.5183", "year": 2019, "title": "Spatial global assessment of the pest Bagrada hilaris (Burmeister)", "abstract": "AbstractBackgroundThe insect Bagrada hilaris (Burmeister) an important pest worldwide, mainly due to the serious economic losses incurred and the large number of zones invaded. However, current and future spatial distributions of this pest, and the total area of cropland potentially affected have not been estimated. Here, we aim to: (1) estimate the potential geographic distribution of B. hilaris; (2) quantify the total area of cropland potentially affected worldwide, and in two recently colonized zones (California and Chile); and (3) estimate future changes in distribution under different climate change scenarios.ResultsWe found that B. hilaris shows high environmental suitability in Mediterranean and arid regions, potentially affecting 1 108 184.1 km2 of cropland worldwide. The most affected continents were Asia and America, with 309 659.8 and 294 638.6 km2 of cropland at risk. More than 50% of cropland areas are at risk in seven countries. In California and central Chile, 43.7% and 50% of susceptible crops are at a high level of risk, respectively. Climate change scenarios predict an increase in the potential distribution of B. hilaris worldwide; America being the most affected continent.ConclusionsOur results provide a spatially explicit baseline from which to focus efforts on the prevention, management and control of this pest worldwide. 2018 Society of Chemical Industry", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/IJERPH19073763", "year": 2022, "title": "Impact of Short-Term Exposure to Extreme Temperatures on Mortality: A", "abstract": "In light of climate change, health risks are expected to be exacerbated by more frequent high temperatures and reduced by less frequent cold extremes. To assess the impact of different climate change scenarios, it is necessary to describe the current effects of temperature on health. A time-stratified case-crossover design fitted with conditional quasi-Poisson regressions and distributed lag non-linear models was applied to estimate specific temperature-mortality associations in nine urban agglomerations in Belgium, and a random-effect meta-analysis was conducted to pool the estimates. Based on 307,859 all-cause natural deaths, the mortality risk associated to low temperature was 1.32 (95% CI: 1.211.44) and 1.21 (95% CI: 1.081.36) for high temperature relative to the minimum mortality temperature (23.1 C). Both cold and heat were associated with an increased risk of cardiovascular and respiratory mortality. We observed differences in risk by age category, and women were more vulnerable to heat than men. People living in the most built-up municipalities were at higher risk for heat. Air pollutants did not have a confounding effect. Evidence from this study helps to identify specific populations at risk and is important for current and future public health interventions and prevention strategies.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41467-021-25833-8", "year": 2021, "title": "Modelling the persistence and control of Rift Valley fever virus in a spatially heterogeneous landscape", "abstract": "The persistence mechanisms of Rift Valley fever (RVF), a zoonotic arboviral haemorrhagic fever, at both local and broader geographical scales have yet to be fully understood and rigorously quantified. We developed a mathematical metapopulation model describing RVF virus transmission in livestock across the four islands of the Comoros archipelago, accounting for island-specific environments and inter-island animal movements. By fitting our model in a Bayesian framework to 20042015 surveillance data, we estimated the importance of environmental drivers and animal movements on disease persistence, and tested the impact of different control scenarios on reducing disease burden throughout the archipelago. Here we report that (i) the archipelago network was able to sustain viral transmission in the absence of explicit disease introduction events after early 2007, (ii) repeated outbreaks during 20042020 may have gone under-detected by local surveillance, and (iii) co-ordinated within-island control measures are more effective than between-island animal movement restrictions.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.IJHEH.2018.04.003", "year": 2018, "title": "Burden of climate change on malaria mortality", "abstract": "In 2016, an estimated 445,000 deaths and 216 million cases of malaria occurred worldwide, while 70% of the deaths occurred in children under five years old. Changes in climatic exposures such as temperature and precipitation make malaria one of the most climate sensitive outcomes. Using a global malaria mortality dataset for 105 countries between 1980 and 2010, we find a non-linear relationship between temperature and malaria mortality and estimate that the global optimal temperature threshold beyond which all-age malaria mortality increases is 20.8 C, while in the case of child mortality; a significantly lower optimum temperature of 19.3 is estimated. Our results also suggest that this optimal temperature is 28.4 C and 26.3 C in Africa and Asia, respectively the continents where malaria is most prevalent. Furthermore, we estimate that child mortality (ages 04) is likely to increase by up to 20% in some areas due to climate change by the end of the 21st century.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/SDATA.2018.256", "year": 2018, "title": "Fluctuations in anthropogenic nighttime lights from satellite imagery for five cities in Niger and Nigeria", "abstract": "Dynamic measures of human populations are critical for global health management but are often overlooked, largely because they are difficult to quantify. Measuring human population dynamics can be prohibitively expensive in under-resourced communities. Satellite imagery can provide measurements of human populations, past and present, to complement public health analyses and interventions. We used anthropogenic illumination from publicly accessible, serial satellite nighttime images as a quantifiable proxy for seasonal population variation in five urban areas in Niger and Nigeria. We identified population fluxes as the mechanistic driver of regional seasonal measles outbreaks. Our data showed 1) urban illumination fluctuated seasonally, 2) corresponding population fluctuations were sufficient to drive seasonal measles outbreaks, and 3) overlooking these fluctuations during vaccination activities resulted in below-target coverage levels, incapable of halting transmission of the virus. We designed immunization solutions capable of achieving above-target coverage of both resident and mobile populations. Here, we provide detailed data on brightness from 20002005 for 5 cities in Niger and Nigeria and detailed methodology for application to other populations.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1186/S13071-021-04851-X", "year": 2021, "title": "Data-driven and interpretable machine-learning modeling to explore the", "abstract": "Abstract\r\n \r\n Background\r\n \r\n Improving the knowledge and understanding of the environmental determinants of malaria vector abundance at fine spatiotemporal scales is essential to design locally tailored vector control intervention. This work is aimed at exploring the environmental tenets of human-biting activity in the main malaria vectors (\r\n Anopheles gambiae s.s.\r\n ,\r\n Anopheles coluzzii\r\n and\r\n Anopheles funestus\r\n ) in the health district of Diebougou, rural Burkina Faso.\r\n \r\n \r\n \r\n Methods\r\n \r\n Anopheles\r\n human-biting activity was monitored in 27 villages during 15 months (in 20172018), and environmental variables (meteorological and landscape) were extracted from high-resolution satellite imagery. A two-step data-driven modeling study was then carried out. Correlation coefficients between the biting rates of each vector species and the environmental variables taken at various temporal lags and spatial distances from the biting events were first calculated. Then, multivariate machine-learning models were generated and interpreted to (i) pinpoint primary and secondary environmental drivers of variation in the biting rates of each species and (ii) identify complex associations between the environmental conditions and the biting rates.\r\n \r\n \r\n \r\n Results\r\n Meteorological and landscape variables were often significantly correlated with the vectors biting rates. Many nonlinear associations and thresholds were unveiled by the multivariate models, for both meteorological and landscape variables. From these results, several aspects of the bio-ecology of the main malaria vectors were identified or hypothesized for the Diebougou area, including breeding site typologies, development and survival rates in relation to weather, flight ranges from breeding sites and dispersal related to landscape openness.\r\n \r\n \r\n Conclusions\r\n Using high-resolution data in an interpretable machine-learning modeling framework proved to be an efficient way to enhance the knowledge of the complex links between the environment and the malaria vectors at a local scale. More broadly, the emerging field of interpretable machine learning has significant potential to help improve our understanding of the complex processes leading to malaria transmission, and to aid in developing operational tools to support the fight against the disease (e.g. vector control intervention plans, seasonal maps of predicted biting rates, early warning systems).\r\n \r\n \r\n Graphical abstract", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ONEHLT.2019.100092", "year": 2019, "title": "Divergent geography of Salmonella wangata and Salmonella typhimurium epidemiology in New South Wales, Australia", "abstract": "Salmonella enterica serovar Wangata is an important cause of salmonellosis in the state of New South Wales, Australia. Standard surveillance has not identified a common food source and cases have been attributed to an unknown environmental or wildlife reservoir. Investigation of the spatial distribution of cases may provide valuable insights into local risk factors for infection and the potential role of the environment and wildlife. Using conditional autoregressive analysis, we explored the association between laboratory-confirmed cases of S. Wangata reported to the New South Wales Department of Health and human socio-demographic, climate, land cover and wildlife features. For comparison, a model was also fitted to investigate the association of cases of Salmonella enterica serovar Typhimurium, an established foodborne serotype, with the same features. To determine if cases of S. Wangata were associated with potential wildlife reservoir species, additional variables were included in the S. Wangata model that indicated areas of high suitability for each species. We found that cases of S. Wangata were associated with warmer temperatures, proximity to wetlands and amphibian species richness. In contrast, cases of S. Typhimurium were associated with human demographic features (proportion of the population comprising children <5 years old), climate (mean annual precipitation and mean annual temperature) and land cover (proportion comprising urban and evergreen broadleaf forest). These findings support the hypothesis that S. Wangata is likely to be associated with an environmental source. Whilst we expected S. Typhimurium to be associated with the human socio-demographic feature, the significance of the land cover features was surprising and might suggest the epidemiology of S. Typhimurium in Australia is more complex than currently understood.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1136/BMJOPEN-2015-009452", "year": 2015, "title": "An ecological analysis of PM2. 5 concentrations and lung cancer mortality rates in China", "abstract": "Objective To explore the association between Particulate Matter (PM)2.5 (particles with an aerodynamic diameter less than 2.5 m) and lung cancer mortality rates and to estimate the potential risk of lung cancer mortality related to exposure to high PM2.5 concentrations.\nDesign Geographically weighted regression was performed to evaluate the relation between PM2.5 concentrations and lung cancer mortality for males, females and for both sexes combined, in 2008, based on newly available long-term data. Lung cancer fatalities from long-term exposure to PM2.5 were calculated according to studies by Pope III et al and the WHO air quality guidelines (AQGs).\nSetting 31 provinces in China.\nResults PM2.5 was associated with the lung cancer mortality of males, females and both sexes combined, in China, although there were exceptions in several regions, for males and females. The number of lung cancer fatalities calculated by the WHO AQGs ranged from 531 036 to 532 004, whereas the number calculated by the American Cancer Society (ACS) reached 614 860 after long-term (approximately 34 years) exposure to PM2.5 concentrations since 2008.\nConclusions There is a positive correlation between PM2.5 and lung cancer mortality rate, and the relationship between them varies across the entire country of China. The number of lung cancer fatalities estimated by ACS was closer to the actual data than those of the WHO AQGs. Therefore, the ACS estimate of increased risk of lung cancer mortality from long-term exposure to PM2.5 might be more applicable for evaluating lung cancer fatalities in China than the WHO estimate.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1029/2021GH000413", "year": 2021, "title": "On the environmental determinants of COVID\u201019 seasonality", "abstract": "Viral respiratory diseases (VRDs), such as influenza and COVID-19, are thought to spread faster during winter than during summer. It has been previously argued that cold and dry conditions are more conducive to the transmission of VRDs than warm and humid climates, although this relationship appears restricted to temperate regions and the causal relationship is not well understood. The severe acute respiratory syndrome coronavirus 2 causing COVID-19 has emerged as a serious global public health problem after the first COVID-19 reports in Wuhan, China, in late 2019. It is still unclear whether this novel respiratory disease will ultimately prove to be a seasonal endemic disease. Here, we suggest that air drying capacity (ADC; an atmospheric state variable that controls the fate/evolution of the virus-laden droplets) and ultraviolet radiation (UV) are probable environmental determinants in shaping the transmission of COVID-19 at the seasonal time scale. These variables, unlike temperature and humidity, provide a physically based framework consistent with the apparent seasonal variability in COVID-19 and prevalent across a broad range of climates (e.g., Germany and India). Since this disease is known to be influenced by the compounding effect of social, biological, and environmental determinants, this study does not claim that these environmental determinants exclusively shape the seasonality of COVID-19. However, we argue that ADC and UV play a significant role in COVID-19 dynamics at the seasonal scale. These findings could help guide the development of a sound adaptation strategy against the pandemic over the coming seasons.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1093/HEAPOL/CZAB078", "year": 2021, "title": "Evaluating urban\u2013rural access to pathology and laboratory medicine services in Tanzania", "abstract": "Placement of pathology and laboratory medicine (PALM) services requires balancing efficiency (maximizing test volume) with equitable urbanrural access. We compared the association between population density (proxy for efficiency) and travel time to the closest facility (proxy for equitable access) across levels of Tanzanias public sector health system. We linked geospatial data for Tanzania from multiple sources. Data on facility locations and other geographic measures were collected from government and non-governmental databases. We classified facilities assuming increasing PALM availability by tier: (1) dispensaries, (2) health centres, (3) district hospitals and (4) regional/referral hospitals. We used the AccessMod 5 algorithm to estimate travel time to the closest facility for each tier across Tanzania with 500-m resolution. District-level average population density and travel time to the closest facility were calculated and presented using medians and interquartile ranges. Spatial correlations between these variables were estimated using the global Morans I and bivariate Local Indicator of Spatial Autocorrelation, specifying a queens neighbourhood matrix. Spatial analysis was restricted to 171 contiguous districts. The study included 5406 dispensaries, 675 health centres, 186 district hospitals and 37 regional/referral hospitals. District-level travel times were shortest for Tier 1 (median: [IQR]: 45.4 min [30.074.7]) and longest for Tier 4 facilities (160.2 min [107.3260.0]). There was a weak spatial autocorrelation across tiers (Tier 1: 0.289, Tier 2: 0.292, Tier 3: 0.271 and Tier 4: 0.258) and few districts were classified as significant spatial outliers. Across tiers, geographic patterns of populated districts surrounded by neighbours with short travel time and sparsely populated districts surrounded by neighbours with long travel time were observed. Similar spatial correlation measures across health system levels suggest that Tanzanias health system reflects equitable urbanrural access to different PALM services. Longer travel times to hospital-based care could be ameliorated by shifting specialized diagnostics to more accessible lower tiers.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0009397", "year": 2021, "title": "Global patterns of aegyptism without arbovirus", "abstract": "The worlds most important mosquito vector of viruses, Aedes aegypti, is found around the world in tropical, subtropical and even some temperate locations. While climate change may limit populations of Ae. aegypti in some regions, increasing temperatures will likely expand its territory thus increasing risk of human exposure to arboviruses in places like Europe, Northern Australia and North America, among many others. Most studies of Ae. aegypti biology and virus transmission focus on locations with high endemicity or severe outbreaks of human amplified urban arboviruses, such as dengue, Zika, and chikungunya viruses, but rarely on areas at the margins of endemicity. The objective in this study is to explore previously published global patterns in the environmental suitability for Ae. aegypti and dengue virus to reveal deviations in the probability of the vector and human disease occurring. We developed a map showing one end of the gradient being higher suitability of Ae. aegypti with low suitability of dengue and the other end of the spectrum being equal and higher environmental suitability for both Ae. aegypti and dengue. The regions of the world with Ae. aegypti environmental suitability and no endemic dengue transmission exhibits a phenomenon we term aegyptism without arbovirus. We then tested what environmental and socioeconomic variables influence this deviation map revealing a significant association with human population density, suggesting that locations with lower human population density were more likely to have a higher probability of aegyptism without arbovirus. Characterizing regions of the world with established populations of Ae. aegypti but little to no autochthonous transmission of human-amplified arboviruses is an important step in understanding and achieving aegyptism without arbovirus.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0009581", "year": 2021, "title": "Modelling the influence of naturally acquired immunity from subclinical infection on outbreak dynamics and persistence of rabies in domestic dogs", "abstract": "A number of mathematical models have been developed for canine rabies to explore dynamics and inform control strategies. A common assumption of these models is that naturally acquired immunity plays no role in rabies dynamics. However, empirical studies have detected rabies-specific antibodies in healthy, unvaccinated domestic dogs, potentially due to immunizing, non-lethal exposure. We developed a stochastic model for canine rabies, parameterised for Laikipia County, Kenya, to explore the implications of different scenarios for naturally acquired immunity to rabies in domestic dogs. Simulating these scenarios using a non-spatial model indicated that low levels of immunity can act to limit rabies incidence and prevent depletion of the domestic dog population, increasing the probability of disease persistence. However, incorporating spatial structure and human response to high rabies incidence allowed the virus to persist in the absence of immunity. While low levels of immunity therefore had limited influence under a more realistic approximation of rabies dynamics, high rates of exposure leading to immunizing non-lethal exposure were required to produce population-level seroprevalences comparable with those reported in empirical studies. False positives and/or spatial variation may contribute to high empirical seroprevalences. However, if high seroprevalences are related to high exposure rates, these findings support the need for high vaccination coverage to effectively control this disease.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/ATMOS12020132", "year": 2021, "title": "Solar Ultraviolet Radiation in Pretoria and Its Relations to Aerosols", "abstract": "Biomass burning has an impact on atmospheric composition as well as human health and wellbeing. In South Africa, the biomass burning season extends from July to October and affects the aerosol loading and tropospheric ozone concentrations which in turn impact solar ultraviolet radiation (UVR) levels at the surface. Using ground-based observations of aerosols, tropospheric ozone and solar UVR (as well as modelled solar UVR) we investigated the impact of aerosols and tropospheric ozone on solar UVR in August, September, and October over Pretoria. Aerosol optical depth (AOD) and tropospheric ozone reached a peak between September and October each year. On clear-sky days, the average relative difference between the modelled and observed solar Ultraviolet Index (UVI) levels (a standard indicator of surface UVR) at solar noon was 7%. Using modelled UVRwhich included and excluded the effects of aerosols and tropospheric ozone from biomass burningaerosols had a larger radiative effect compared to tropospheric ozone on UVI levels during the biomass burning season. Excluding only aerosols resulted in a 10% difference between the modelled and observed UVI, while excluding only tropospheric ozone resulted in a difference of 2%. Further understanding of the radiative effect of aerosols and trace gases, particularly in regions that are affected by emissions from biomass burning, is considered important for future research.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S13280-018-1061-8", "year": 2018, "title": "Framework for mapping the drivers of coastal vulnerability and spatial decision making for climate-change adaptation: A case study from Maharashtra, India", "abstract": "The impacts of climate change are of particular concern to the coastal region of tropical countries like India, which are exposed to cyclones, floods, tsunami, seawater intrusion, etc. Climate-change adaptation presupposes comprehensive assessment of vulnerability status. Studies so far relied either on remote sensing-based spatial mapping of physical vulnerability or on certain socio-economic aspects with limited scope for upscaling or replication. The current study is an attempt to develop a holistic and robust framework to assess the vulnerability of coastal India at different levels. We propose and estimate cumulative vulnerability index (CVI) as a function of exposure, sensitivity and adaptive capacity, at the village level, using nationally comparable and credible datasets. The exposure index (EI) was determined at the village level by decomposing the spatial multi-hazard maps, while sensitivity (SI) and adaptive capacity indices (ACI) were estimated using 23 indicators, covering social and economic aspects. The indicators were identified through the literature review, expert consultations, opinion survey, and were further validated through statistical tests. The socio-economic vulnerability index (SEVI) was constructed as a function of sensitivity and adaptive capacity for planning grassroot-level interventions and adaptation strategies. The framework was piloted in Sindhudurg, a coastal district in Maharashtra, India. It comprises 317 villages, spread across three taluks viz., Devgad, Malvan and Vengurla. The villages in Sindhudurg were ranked based on this multi-criteria approach. Based on CVI values, 92 villages (30%) in Sindhudurg were identified as highly vulnerable. We propose a decision tool for identifying villages vulnerable to changing climate, based on their level of sensitivity and adaptive capacity in a two-dimensional matrix, thus aiding in planning location-specific interventions. Here, vulnerability indicators are classified and designated as drivers (indicators with significantly high values and intervention priority) and buffers (indicators with low-to-moderate values) at the village level. The framework provides for aggregation or decomposition of CVI and other sub-indices, in order to plan spatial contingency plans and enable swift action for climate adaptation.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.AGRFORMET.2014.06.009", "year": 2014, "title": "Using evapotranspiration to assess drought sensitivity on a subfield scale with HRMET, a high resolution surface energy balance model", "abstract": "Evapotranspiration (ET) rates provide a valuable within-season indicator of plant productivity, as well as data on fluxes of water in a landscape. Applying remote sensing for ET estimation has potential to improve the sustainable management of water resources in agricultural settings. Most current ET models, however, rely on dry and wet pixels within a given scene to partition turbulent fluxes between latent and sensible heat, thus limiting their ability to map ET throughout the growing season at extremely high (meter scale) spatial resolutions. Here, we develop a field-validated surface energy balance model, High Resolution Mapping of EvapoTranspiration (HRMET), which requires only basic meteorological data, spatial surface temperature and canopy structure data. We use HRMET to estimate ET rates over two commercial cornfields in south-central Wisconsin during the 2012 growing season, which was characterized by severe drought. HRMET results indicate that the magnitude of within-field variability in ET rates was primarily driven by water availability. The application of remotely sensed data to precision agriculture has also been hampered by turnaround time between image acquisition and availability. We introduce relative ET (ETR), which enables comparison of ET rates between image dates by normalizing for variability caused by weather and crop stage. ETR also provides an intuitive, index-like metric for evaluating spatial variability in ET on a subfield scale. ETR maps illuminate persistent patterns in ET across measurement dates that may be driven by soil water availability and topography. ETR is used to develop a novel paired-image technique that can map subfield sensitivity classes to stressors such as drought. Sensitivity class mapping can be used to circumvent issues related to turnaround time to facilitate the incorporation of remotely sensed data into precision agriculture.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS12142332", "year": 2020, "title": "Uncovering Dryland Woody Dynamics Using Optical, Microwave, and Field", "abstract": "Dryland ecosystems are frequently struck by droughts. Yet, woody vegetation is often able to recover from mortality events once precipitation returns to pre-drought conditions. Climate change, however, may impact woody vegetation resilience due to more extreme and frequent droughts. Thus, better understanding how woody vegetation responds to drought events is essential. We used a phenology-based remote sensing approach coupled with field data to estimate the severity and recovery rates of a large scale die-off event that occurred in 20142015 in Senegal. Novel low (L-band) and high-frequency (Ku-band) passive microwave vegetation optical depth (VOD), and optical MODIS data, were used to estimate woody vegetation dynamics. The relative importance of soil, human-pressure, and before-drought vegetation dynamics influencing the woody vegetation response to the drought were assessed. The die-off in 20142015 represented the highest dry season VOD drop for the studied period (19892017), even though the 2014 drought was not as severe as the droughts in the 1980s and 1990s. The spatially explicit Die-off Severity Index derived in this study, at 500 m resolution, highlights woody plants mortality in the study area. Soil physical characteristics highly affected die-off severity and post-disturbance recovery, but pre-drought biomass accumulation (i.e., in areas that benefited from above-normal rainfall conditions before the 2014 drought) was the most important variable in explaining die-off severity. This study provides new evidence supporting a better understanding of the greening Sahel, suggesting that a sudden increase in woody vegetation biomass does not necessarily imply a stable ecosystem recovery from the droughts in the 1980s. Instead, prolonged above-normal rainfall conditions prior to a drought may result in the accumulation of woody biomass, creating the basis for potentially large-scale woody vegetation die-off events due to even moderate dry spells.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1111/GCB.15026", "year": 2020, "title": "Weather underground: Subsurface hydrologic processes mediate tree", "abstract": "AbstractDrought extent and severity have increased and are predicted to continue to increase in many parts of the world. Understanding tree vulnerability to drought at both individual and species levels is key to ongoing forest management and preparation for future transitions in community composition. The influence of subsurface hydrologic processes is particularly important in waterlimited ecosystems, and is an understudied aspect of tree drought vulnerability. With California's 20132016 extraordinary drought as a natural experiment, we studied four cooccurring woodland tree species, blue oak (Quercus douglasii), valley oak (Quercus lobata), gray pine (Pinus sabiniana), and California juniper (Juniperus californica), examining drought vulnerability as a function of climate, lithology and hydrology using regional aerial dieback surveys and sitescale field surveys. We found that in addition to climatic drought severity (i.e., rainfall), subsurface processes explained variation in drought vulnerability within and across species at both scales. Regionally for blue oak, severity of dieback was related to the bedrock lithology, with higher mortality on igneous and metamorphic substrates, and to regional reductions in groundwater. At the site scale, access to deep subsurface water, evidenced by stem water stable isotope composition, was related to canopy condition across all species. Along hillslope gradients, channel locations supported similar environments in terms of water stress across a wide climatic gradient, indicating that subsurface hydrology mediates species experience of drought, and that areas associated with persistent access to subsurface hydrologic resources may provide important refugia at species xeric range edges. Despite this persistent overall influence of the subsurface environment, individual species showed markedly different response patterns. We argue that hydrologic niche segregation can be a useful lens through which to interpret these differences in vulnerability to climatic drought and climate change.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/NHESS-22-3737-2022", "year": 2022, "title": "Analysis of the relationship between yield in cereals and remotely sensed fAPAR in the framework of monitoring drought impacts in Europe", "abstract": "Abstract. This study focuses on the relationship between satellite-measured fraction of absorbed photosynthetically active radiation (fAPAR) and crop yield cereals in Europe. Different features of the relationship between annual yield and multiple time series of fAPAR, collected during different periods of the year, were investigated. The two key outcomes of the analysis are the identification of the period: (i) from March to October as the one having the highest positive correlation between fAPAR and yield and (ii) from February to May as the period characterised by most of the estimated negative correlation. While both periods align well with the commonly assumed dynamic of the growing season, spatial differences are also observed across Europe. On the one hand, the Mediterranean regions report the highest correlation values (r>0.8) and the longest continuous periods with positive statistically significant results (up to 7 months), covering most of the growing season. On the other hand, the central European region is characterised by the most limited positive correlation values, with only 2 months or less showing statistically significant results. While marked differences in the overall capability to capture the full dynamic of yield are observed across Europe, fAPAR anomalies seem capable of discriminating low-yield years from the rest in most of the cases.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1002/JOC.7302", "year": 2021, "title": "Global exposure of population and land\u2010use to meteorological droughts under different warming levels and SSPs: A CORDEX\u2010based study", "abstract": "Global warming is likely to cause a progressive drought increase in some regions, but how population and natural resources will be affected is still underexplored. This study focuses on global population, forests, croplands and pastures exposure to meteorological drought hazard in the 21st century, expressed as frequency and severity of drought events. As input, we use a large ensemble of climate simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), population projections from the NASA-SEDAC dataset and land-use projections from the Land-Use Harmonization 2 project for 1981-2100. The exposure to drought hazard is presented for five Shared Socioeconomic Pathways (SSP1-SSP5) at four Global Warming Levels (GWLs: 1.5\u00b0C to 4\u00b0C). Results show that considering only Standardized Precipitation Index (SPI; based on precipitation), the SSP3 at GWL4 projects the largest fraction of the global population (14%) to experience an increase in drought frequency and severity (versus 1981-2010), with this value increasing to 60% if temperature is considered (indirectly included in the Standardized Precipitation-Evapotranspiration Index, SPEI). With SPEI, considering the highest GWL for each SSP, 8 (for SSP2, SSP4, SSP5) and 11 (SSP3) billion people, that is, more than 90%, will be affected by at least one unprecedented drought. For SSP5 at GWL4, approximately 2 \u00d7 106 km2 of forests and croplands (respectively, 6% and 11%) and 1.5 \u00d7 106 km2 of pastures (19%) will be exposed to increased drought frequency and severity according to SPI, but for SPEI this extent will rise to 17 \u00d7 106 km2 of forests (49%), 6 \u00d7 106 km2 of pastures (78%) and 12 \u00d7 106 km2 of croplands (67%), being mid-latitudes the most affected. The projected likely increase of drought frequency and severity significantly increases population and land-use exposure to drought, even at low GWLs, thus extensive mitigation and adaptation efforts are needed to avoid the most severe impacts of climate change.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2021JG006525", "year": 2022, "title": "Effects of Increased Drought in Amazon Forests Under Climate Change:", "abstract": "The Amazon forests are one of the largest ecosystem carbon pools on Earth. Although more frequent and prolonged future droughts have been predicted, the impacts have remained largely uncertain, as most land surface models (LSMs) fail to capture the vegetation drought responses. In this study, the ability of the LSM JSBACH to simulate the drought responses of leaf area index (LAI) and leaf litter production in the Amazon forests is evaluated against artificial drought experiments. Based on the evaluation, improvements are implemented, including a dependency of leaf growth on leaf carbon allocation and a better representation of drought-dependent leaf shedding. The modified JSBACH is shown to capture the drought responses at two sites and across different regions of the basin. It is then coupled with an atmospheric model to simulate the carbon and biogeophysical feedbacks of drought under future climate. We separate the drought impacts into (a) the direct effect, resulting from drier soil and stomatal closure, which does not involve a change in canopy structure, and (b) the LAI effect, resulting from leaf shedding and involving canopy response. We show that the latter accounts for 35% of reduced land carbon uptake (9 \u00b1 10 vs. 26 \u00b1 7 g/m2/yr; mean \u00b1 1 sd) and 12% of surface warming (0.09 \u00b1 0.03 vs. 0.7 \u00b1 0.07 K) during the late 21st century. A north-south dipole of precipitation change is found, which is largely attributable to the direct effect. The results highlight the importance of incorporating drought deciduousness of tropical rainforests in LSMs to better simulate land-atmosphere interactions in the future.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1007/S00477-021-02137-3", "year": 2021, "title": "Comparative analysis of two drought indices in the calculation of drought recovery time and implications on drought assessment: East Africa's Lake Victoria Basin", "abstract": "Drought imposes severe, long-term effects on global environments and ecosystems. A better understanding of how long it takes a region to recover to pre-drought conditions after drought is essential for addressing future ecology risks. In this study, drought-related variables were obtained using remote sensing and reanalysis products for 2003 to 2016. The meteorological drought index [standardized precipitation evapotranspiration index (SPEI)] and agricultural drought index [vegetation condition index (VCI)] were employed to estimate drought duration time (DDT) and drought recovery time (DRT). To the basins west, decreasing rainfall and increasing potential evapotranspiration led to decreasing SPEI. On the east side, decreasing soil moisture from each depth effects vegetation condition, which results in a decreasing gross primary productivity and VCI. Extreme meteorological drought events are likely to occur in the basins northeastern and middle western areas, while the southern basin is more likely to suffer from extreme agricultural drought events. The mean SPEI-based DDT (2.45 months) was smaller than the VCI-based DDT (2.97 months); the average SPEI-based DRT (2.02 months) was larger than the VCI-based DRT (1.63 months). Most of the area needs 1 or 2 months to recover from drought except for the basins northwestern area, where the DRT is more than 8 months. DDT is the most important parameter in determining DRT. These results provide useful information about regional drought recovery that will help local governments looking to mitigate potential environmental risks and formulate appropriate agricultural policies in Lake Victoria Basin.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS11242902", "year": 2019, "title": "Quantifying Drought Sensitivity of Mediterranean Climate Vegetation to Recent Warming: A Case Study in Southern California", "abstract": "A combination of drought and high temperatures (global-change-type drought) is projected to become increasingly common in Mediterranean climate regions. Recently, Southern California has experienced record-breaking high temperatures coupled with significant precipitation deficits, which provides opportunities to investigate the impacts of high temperatures on the drought sensitivity of Mediterranean climate vegetation. Responses of different vegetation types to drought are quantified using the Moderate Resolution Imaging Spectroradiometer (MODIS) data for the period 20002017. The contrasting responses of the vegetation types to drought are captured by the correlation and regression coefficients between Normalized Difference Vegetation Index (NDVI) anomalies and the Palmer Drought Severity Index (PDSI). A novel bootstrapping regression approach is used to decompose the relationships between the vegetation sensitivity (NDVIPDSI regression slopes) and the principle climate factors (temperature and precipitation) associated with the drought. Significantly increased sensitivity to drought in warmer locations indicates the important role of temperature in exacerbating vulnerability; however, spatial precipitation variations do not demonstrate significant effects in modulating drought sensitivity. Based on annual NDVI response, chaparral is the most vulnerable community to warming, which will probably be severely affected by hotter droughts in the future. Drought sensitivity of coastal sage scrub (CSS) is also shown to be very responsive to warming in fall and winter. Grassland and developed land will likely be less affected by this warming. The sensitivity of the overall vegetation to temperature increases is particularly concerning, as it is the variable that has had the strongest secular trend in recent decades, which is expected to continue or strengthen in the future. Increased temperatures will probably alter vegetation distribution, as well as possibly increase annual grassland cover, and decrease the extent and ecological services provided by perennial woody Mediterranean climate ecosystems as well.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2021EF002555", "year": 2022, "title": "Relic Groundwater and Prolonged Drought Confound Interpretations of Water Sustainability and Lithium Extraction in Arid Lands", "abstract": "Demand for lithium for batteries is growing rapidly with the global push to decarbonize energy systems. The Salar de Atacama, Chile holds \u223c42% of the planet's reserves in the form of brine hosted in massive evaporite aquifers. The mining of these brines and associated freshwater use has raised concerns over the environmental responsibility of lithium extraction, yet large uncertainties remain regarding fundamental aspects of governing hydrological processes in these environments. This incomplete understanding has led to the perpetuation of misconceptions about what constitutes sustainable or renewable water use and therefore what justifies responsible allocation. We present an integrated hydrological assessment using tritium and stable oxygen, and hydrogen isotopes paired with remotely sensed and terrestrial hydroclimate data to define unique sources of water distinguished by residence time, physical characteristics, and connectivity to modern climate. Our results describe the impacts of prolonged drought on surface and groundwaters and demonstrate that nearly all inflow to the basin is composed of water recharged >65 years ago. Still, modern precipitation is critical to sustaining important wetlands around the salar. Recent large rain events have increased surface water and vegetation extents and terrestrial water storage while mining-related water withdrawals have continued. As we show, poor conceptualizations of these complex hydrological systems have perpetuated the misallocation of water and the misattribution of impacts. These fundamental issues apply to arid regions globally. Our new framework for hydrological assessment in these basins moves beyond calculating gross inputs-outputs at a steady state to include all compartmentalized stores that constitute \"modern\" budgets.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S00382-007-0349-3", "year": 2008, "title": "Mediterranean drought fluctuation during the last 500 years based on tree-ring data", "abstract": "A 2.5 \u00d7 2.5\u00b0 gridded summer (April-September) drought reconstruction over the larger Mediterranean land area (32.5\u00b0/47.5\u00b0N, 10\u00b0W/50\u00b0E; 152 grid points) is described, based on a network of 165 tree-ring series. The drought index used is the self-calibrated Palmer Drought Severity Index, and the period considered is 1500-2000. The reconstruction technique combines an analogue technique for the estimation of missing tree-ring data with an artificial neural network for optimal non-linear calibration, including a bootstrap error assessment. Tests were carried out on the various sources of error in the reconstructions. Errors related to the temporal variations of the number of proxies were tested by comparing four reconstructions calibrated with four different sized regressor datasets, representing the decrease in the number of available proxies over time. Errors related to the heterogeneous spatial density of predictors were tested using pseudo-proxies, provided by the global climate model ECHO-G. Finally the errors related to the imperfect climate signal recorded by tree-ring series were tested by adding white noise to the pseudo-proxies. Reconstructions pass standard cross-validation tests. Nevertheless tests using pseudo-proxies show that the reconstructions are less good in areas where proxies are rare, but that the average reconstruction curve is robust. Finally, the noise added to proxies, which is by definition a high frequency component, has a major effect on the low frequency signal, but not on the medium frequencies. The comparison of the low frequency trends of our mean reconstruction and the GCM simulation indicates that the detrending method used is able to preserve the long-term variations of reconstructed PDSI. The results also highlight similar multi-decadal PDSI variations in the central and western parts of the Mediterranean basin and less clear low frequency changes in the east. The sixteenth and the first part of the seventeenth centuries are characterized by marked dry episodes in the west similar to those observed in the end of the twentieth century. In contrast, the eighteenth and nineteenth centuries (Little Ice Age) are characterized by dominant wet periods. In the eastern part of the Mediterranean basin the observed strong drought period of the end of the twentieth century seems to be the strongest of the last 500 years.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.15201/HUNGEOBULL.68.3.5", "year": 2019, "title": "Geospatial analysis of drought tendencies in the Carpathians as reflected in a 50-year time series", "abstract": "Climate change is one of the most important issues of anthropogenic activities. The increasing drought conditions can cause water shortage and heat waves and can influence the agricultural production or the water supply of cities. The Carpathian region is also affected by this phenomenon; thus, we aimed at identifying the tendencies between 1960 and 2010 applying the CarpatClim (CC) database. We calculated the trends for each grid point of CC, plotted the results on maps, and applied statistical analysis on annual and seasonal level. We revealed that monthly average temperature, maximum temperature and evapotranspiration had similar patterns and had positive trends in all seasons except autumn. Precipitation also had a positive trend, but it had negative values in winter. The geospatial analysis disclosed an increasing trend from West to East and from north to west. A simple binary approach (value of 1 above the upper quartile in case of temperature and evapotranspiration, value of 1 below the lower quartile; 0 for the rest of the data) helped to identify the most sensitive areas where all the involved climatic variables exceeded the threshold: Western Hungary and Eastern Croatia. Results can help to prepare possible mitigation strategies to climate change and both landowners and planners can draw the conclusions.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1088/1748-9326/AC9852", "year": 2022, "title": "Opposite eco-hydrological processes in flood and drought years caused", "abstract": "Abstract\r\n While the influences of droughts on Amazon rainforest have been extensively examined, little attention was paid to the extremely wet years characterized by low radiation which may limit the rainforest growth. Here, based on a series of satellite-observed vegetation and hydro-meteorological products, we found a two-stage canopy growth anomaly in the record-breaking wet year 2009, i.e. negative anomalies during AprilJuly followed by positive ones during AugustNovember. Our analysis suggests that, in AprilJuly, low radiation associated with above-average rainfall and cloud cover was the most likely cause for negative anomalies in the canopy growth. In AugustNovember, the rainfall and cloud cover were close to the average, but the solar radiation reaching the land surface was considerably above the average. This was because the atmospheric aerosols were extremely low, resulting from reduced biomass burning activities under the wet conditions. Large-scale positive anomalies in the canopy growth were observed during this 4 month period, mainly driven by the above-average radiation. During the severe drought year 2005, the forest canopy growth also experienced a two-stage process, but in the opposite order from the one in 2009. In AprilJuly, enhanced canopy growth was observed in response to the above-average radiation. With the drought progress and soil water depletion, the canopy senescence was observed during the drought peak in AugustNovember. Interestingly, if we examined the regional canopy growth anomaly during the typical dry season (i.e. JulySeptember), both years showed similarly negative anomalies, but resulting from opposite eco-hydrological processes. This study identifies the explanation for the negative anomalies in the dry-season canopy growth over southern Amazon rainforest in both flood and drought years, and also underscores the necessity to separate different hydro-meteorological stages to better understand vegetation responses to extreme events.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2021.126802", "year": 2021, "title": "More severe drought detected by the assimilation of brightness temperature and terrestrial water storage anomalies in Texas during 2010\u20132013", "abstract": "Texas experienced an extreme drought on record in 2011. Model simulations or satellite observations have been used to assess and analyze the drought. In this study, a method based on multi-source remote sensing data assimilation is proposed to evaluate the drought in Texas, which combines the advantages of model simulations and satellite observations. Brightness temperature from the Soil Moisture and Ocean Salinity (SMOS), the Advanced Microwave Scanning Radiometer for EOS/Advanced Microwave Scanning Radiometer 2 (AMSR-E/AMSR2) and terrestrial water storage anomalies from the Gravity Recovery and Climate Experiment (GRACE) are assimilated into the Noah-Multiparameterization model (Noah-MP) to improve the soil moisture and drought estimation. The Ensemble Kalman Filter (EnKF) was used as a data assimilation method with observation aggregation (dealing with the multi-resolution observations) and observation bias correction (dealing with the systematic bias between observations and simulations). Data from ground stations and satellites are used for the validation of soil moisture, terrestrial water storage anomalies, and evapotranspiration. With assimilation, slight improvement can be found for surface soil moisture over the open-loop configuration, but some notable degradations are also observed. More obvious improvement can be found at deep layers, which is mainly due to the assimilation of terrestrial water storage anomalies. In addition, the improvement for terrestrial water storage anomalies and evapotranspiration is more statistically significant in most regions of Texas. Overall, the assimilation experiment plays a positive role in the estimation of essential variables relate to drought. The drought is estimated using the soil moisture percentile and classified into five categories. The results from the assimilation experiment tend to predict a more severe drought in Texas for both magnitude and spatial patterns, which indicates not only the well-known drought in 2011 but also the continuous severe drought in 2012 and 2013. Moreover, the spatial distribution of drought reveals that drought occurred more frequently in the North, West, and Southwest.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/NHESS-21-481-2021", "year": 2021, "title": "A revision of the Combined Drought Indicator (CDI) used in the European Drought Observatory (EDO)", "abstract": "Abstract. Building on almost 10 years of expertise and operational application of the Combined Drought Indicator (CDI), which is implemented within the European Commission's European Drought Observatory (EDO) for the purposes of early warning and monitoring of agricultural droughts in Europe, this paper proposes a revised version of the index. The CDI conceptualizes drought as a cascade process, where a precipitation shortage (WATCH stage) develops into a soil water deficit (WARNING stage), which in turn leads to stress for vegetation (ALERT stage). The main goal of the revised CDI proposed here is to improve the indicator's performance for those events that are currently not reliably represented, without altering either the modelling conceptual framework or the required input datasets. This is achieved by means of two main modifications: (a) use of the previously occurring CDI value to improve the temporal consistency of the time series and (b) introduction of two temporary classes namely TEMPORARY RECOVERY for soil moisture and vegetation greenness, respectively to avoid brief discontinuities in a stage. The efficacy of the modifications is tested by comparing the performances of the revised and currently implemented versions of the indicator for actual drought events in Europe during the last 20 years. The revised CDI reliably reproduces the evolution of major droughts, outperforming the current version of the indicator, especially for long-lasting events, and reducing the overall temporal inconsistencies in stage sequencing of about 70 %. Since the revised CDI does not need supplementary input datasets, it is suitable for operational implementation within the EDO drought monitoring system.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1088/1748-9326/AC507A", "year": 2022, "title": "Eco-hydrological responses to recent droughts in tropical South America", "abstract": "Abstract\r\n This study assesses the ecohydrological effects of recent meteorological droughts in tropical South America based on multiple sources of data, and investigates the possible mechanisms underlying the drought response and recovery of different ecohydrological systems. Soil drought response and recovery lag behind the meteorological drought, with delays longer in the dry region (Nordeste) than in the wet region (Amazonia), and longer in deep soil than in shallow soil. Evapotranspiration (ET) and vegetation in Nordeste are limited by water under normal conditions and decrease promptly in response to the onset of shallow soil drought. In most of the Amazon where water is normally abundant, ET and vegetation indices follow an increase-then-decrease pattern, increase at the drought onset due to increased sunshine and decrease when the drought is severe enough to cause a shift from an energy-limited regime to a water-limited regime. After the demise of meteorological droughts, ET and vegetation rapidly recover in Nordeste with the replenishment of shallow soil moisture (SM), but take longer to recover in southern Amazon due to their dependence on deep SM storage. Following severe droughts, the negative anomalies of ET and vegetation indices in southern Amazon tend to persist well beyond the end of soil drought, indicating drought-induced forest mortality that is slow to recover from. Findings from this study may have implications on the possibility of a future forest dieback as drought is projected to become more frequent and more severe in a warmer climate.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS12142257", "year": 2020, "title": "Inspecting the Food\u2013Water Nexus in the Ogallala Aquifer Region Using Satellite Remote Sensing Time Series", "abstract": "Agricultural production in the Great Plains provides a significant amount of food for the United States while contributing greatly to farm income in the region. However, recurrent droughts and expansion of crop production are increasing irrigation demand, leading to extensive pumping and attendant depletion of the Ogallala aquifer. In order to optimize water use, increase the sustainability of agricultural production, and identify best management practices, identification of foodwater conflict hotspots in the Ogallala Aquifer Region (OAR) is necessary. We used satellite remote sensing time series of agricultural production (net primary production, NPP) and total water storage (TWS) to identify hotspots of foodwater conflicts within the OAR and possible reasons behind these conflicts. Mean annual NPP (20012018) maps clearly showed intrusion of high NPP, aided by irrigation, into regions of historically low NPP (due to precipitation and temperature). Intrusion is particularly acute in the northern portion of OAR, where mean annual TWS (20022020) is high. The Oklahoma panhandle and Texas showed large decreasing TWS trends, which indicate the negative effects of current water demand for crop production on TWS. Nebraska demonstrated an increasing TWS trend even with a significant increase of NPP. A regional analysis of NPP and TWS can convey important information on current and potential conflicts in the foodwater nexus and facilitate sustainable solutions. Methods developed in this study are relevant to other water-constrained agricultural production regions.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1002/JOC.6400", "year": 2020, "title": "Contrasting drought impacts on the start of phenological growing season", "abstract": "Drought is a widely occurring extreme climatic event that may have various effects on vegetation phenology and activity. The change of the start of the phenological growing season (SOS) is one key mechanism for ecosystem responses to droughts yet remain unknown at large scale. This study used abnormal changes in the ratio of reference evapotranspiration (ETO) and precipitation (P) to detect the pre\u2011season (defined as the 3 months before the growing season) monthly drought during 1982\u20132015. After that, the pre\u2011season drought impacts on SOS were analysed. Drought appeared frequently (>3.6 times/10 years) in the northern and southwest China, as well as the coastal area of south China during the last 34 years. The droughts generally accompany a higher temperature and a stronger radiation, but the drought effects on the SOS differ between humid/sub\u2011humid and semi\u2011arid zones in northern China. Specifically, in the temperate humid/sub\u2011humid zones, SOS under drought was 1.08\u20134.86 days earlier than during normal (no drought) years, and the response was greater to the droughts that appeared in the first two of the three pre\u2011season months. In addition, in the cold, mid\u2011, and warm temperate zones, the advance response was more concentrated in the SOS about DOY130\u2011140, DOY125\u2011150, and DOY80\u2011160, respectively. However, in the north semi\u2011arid zone, the SOS under drought was 0.66\u20133.45 days later than during normal years, and the response was greater to the droughts that appeared in the last two of the 3 months. These delay responses also concentrated in the SOS about DOY125\u2011150. The contrasting drought impacts on phenology suggest that we should move beyond the vegetation activity under droughts such as the growth, productivity, and mortality, and pay more attention to the timing of vegetation activity to better quantify the carbon budget at Northern Hemisphere.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1080/00330124.2020.1730197", "year": 2020, "title": "A New Index to Better Detect and Monitor Agricultural Drought in Niger Using Multisensor Remote Sensing Data", "abstract": "In this study, we propose a new remote sensingbased drought index, the agricultural drought condition index (ADCI), for agricultural drought monitoring in the agricultural area of Niger. It is defined as a first principal component analysis (PCA) of precipitation condition index (PCI), vegetation condition index (VCI), temperature condition index (TCI), and evapotranspiration condition index (ETCI). ADCI integrates multisource remote sensing data from Climate Hazards group Infrared Precipitation with Station (CHIRPS) and moderate resolution imaging spectro-radiometer (MODIS) and it synthesizes precipitation deficits, vegetation growth status, soil thermal stress, and crop water stress in the drought process. A series of validation tests have been implemented using a one-month standardized precipitation index (SPI-1), the crop yield and the vegetation health index (VHI) during the crop growth period (JuneOctober) from 2003 to 2017. The results show that ADCI is not only strongly correlated with SPI-1, but also with the variation of crop yield and the VHI. When tested against VHI, the ADCI performed better than VHI. Thus, it was proven that this index is a full drought monitoring indicator and it can not only contain the meteorological drought information, but also reflect drought influence on agriculture.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JHYDROL.2020.125283", "year": 2020, "title": "Drought evaluation over Yangtze River basin based on weighted water storage deficit", "abstract": "The ability of Gravity Recovery and Climate Experiment (GRACE) to monitor large scale drought events has been explored well during past few years. We develop an alternative method viz.,weighted water storage deficit (WWSD) to characterize drought events over Yangtze river basin (YRB) based on water storage deficit (WSD) method by combining GRACE RL06 sphere harmonic (SH) coefficient data and WaterGAP Global Hydrology Model(WGHM) data. We use component contribution ratio (CCR) of single terrestrial water compartment as weight to compute WWSD, comparing with other commonly employed drought indices and precipitation data from Global Precipitation Measurement(GPM). The results show that precipitation is the major trigger of water storage variation over YRB, which both have significant seasonal change. Our findings also indicate different terrestrial water component contributes distinctly to terrestrial water storage (TWS) variability and responds differently to drought features in YRB according to water component storage deficit (WCSD). Eleven drought events are identified in YRB based on WWSD with 2003, 2006 and 2011 experiencing the severest drought with drought intensity of 1.22 cm, 1.34 cm and 1.02 cm, respectively. Our study suggests that it is more realistic and reasonable to treat water components unequally to construct drought index derived from GRACE.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.RSE.2021.112478", "year": 2021, "title": "Evaluating the benefits of chlorophyll fluorescence for in-season crop productivity forecasting", "abstract": "Remote sensing of solar-induced chlorophyll fluorescence (SIF) shows promise for monitoring the productivity of global agricultural systems. SIF-based primary productivity metrics have demonstrated higher fidelity to large-scale patterns of crop productivity than reflectance-based vegetation indices when averaged across the growing season. In-season crop yield forecasting typically relies upon reflectance-based vegetation indices, raising the question of whether in-season monitoring could be improved by utilizing SIF. Here, we analyze patterns of US agricultural productivity from USDA surveys and their in-season relationships with coarse-resolution GOME-2 SIF, high-resolution downscaled SIF, SIF-based primary productivity metrics, MODIS NDVI, and MODIS GPP. We find that coarse-resolution SIF-based metrics and NDVI exhibit similar out-of-sample in-season (AprilJuly and AprilAugust) predictive ability, even when spatially filtering higher-resolution NDVI data to cropland areas. The downscaled SIF product performed more poorly than the coarse-resolution SIF, and MODIS GPP performed more poorly than MODIS NDVI. All forecasts are improved by incorporating county fixed effects to control for cross-sectional differences between counties. NDVI-based metrics allow for significantly better yield predictions during drought conditions than SIF-based metrics, suggesting limited added value of SIF for early warning of drought impacts. The benefits of SIF for crop monitoring should be continually evaluated as the frequency and quality of SIF measurements continue to improve.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/HESS-21-1947-2017", "year": 2017, "title": "Testing the use of standardised indices and GRACE satellite data to estimate the European 2015 groundwater drought in near-real time", "abstract": "Abstract. In 2015, central and eastern Europe were affected by a severe drought. This event has recently been studied from meteorological and streamflow perspective, but no analysis of the groundwater situation has been performed. One of the reasons is that real-time groundwater level observations often are not available. In this study, we evaluate two alternative approaches to quantify the 2015 groundwater drought over two regions in southern Germany and eastern Netherlands. The first approach is based on spatially explicit relationships between meteorological conditions and historic groundwater level observations. The second approach uses the Gravity Recovery Climate Experiment (GRACE) terrestrial water storage (TWS) and groundwater anomalies derived from GRACE-TWS and (near-)surface storage simulations by the Global Land Data Assimilation System (GLDAS) models. We combined the monthly groundwater observations from 2040 wells to establish the spatially varying optimal accumulation period between the Standardised Groundwater Index (SGI) and the Standardized Precipitation Evapotranspiration Index (SPEI) at a 0.25 gridded scale. The resulting optimal accumulation periods range between 1 and more than 24 months, indicating strong spatial differences in groundwater response time to meteorological input over the region. Based on the estimated optimal accumulation periods and available meteorological time series, we reconstructed the groundwater anomalies up to 2015 and found that in Germany a uniform severe groundwater drought persisted for several months during this year, whereas the Netherlands appeared to have relatively high groundwater levels. The differences between this event and the 2003 European benchmark drought are striking. The 2003 groundwater drought was less uniformly pronounced, both in the Netherlands and Germany. This is because slowly responding wells (the ones with optimal accumulation periods of more than 12 months) still were above average from the wet year of 2002, which experienced severe flooding in central Europe. GRACE-TWS and GRACE-based groundwater anomalies did not capture the spatial variability of the 2003 and 2015 drought events satisfactorily. GRACE-TWS did show that both 2003 and 2015 were relatively dry, but the differences between Germany and the Netherlands in 2015 and the spatially variable groundwater drought pattern in 2003 were not captured. This could be associated with the coarse spatial scale of GRACE. The simulated groundwater anomalies based on GRACE-TWS deviated considerably from the GRACE-TWS signal and from observed groundwater anomalies. The uncertainty in the GRACE-based groundwater anomalies mainly results from uncertainties in the simulation of soil moisture by the different GLDAS models. The GRACE-based groundwater anomalies are therefore not suitable for use in real-time groundwater drought monitoring in our case study regions. The alternative approach based on the spatially variable relationship between meteorological conditions and groundwater levels is more suitable to quantify groundwater drought in near real-time. Compared to the meteorological drought and streamflow drought (described in previous studies), the groundwater drought of 2015 had a more pronounced spatial variability in its response to meteorological conditions, with some areas primarily influenced by short-term meteorological deficits and others influenced by meteorological deficits accumulated over the preceding 2 years or more. In drought management, this information is very useful and our approach to quantify groundwater drought can be used until real-time groundwater observations become readily available.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/ENGPROC2021009024", "year": 2021, "title": "Drought Periods Identification in Ecuador between 2001 and 2018 Using SPEI and MODIS Data", "abstract": "Drought is a natural phenomenon in which the precipitation amount is below normal in a specific region over a long period. The main objective of this study is to identify periods of drought in Ecuador between 2001 and 2018 using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Normalized Difference Water Index (NDWI) derived from MODIS data. Firstly, the SPEI at a six-month scale and the Runs theory were used to identify periods of drought. Secondly, the NDWI from MOD09A1 MODIS product was used to identify the areas affected by drought.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS12071202", "year": 2020, "title": "OCO-2 Solar-Induced Chlorophyll Fluorescence Variability across Ecoregions of the Amazon Basin and the Extreme Drought Effects of El Nino (20152016)", "abstract": "Amazonian ecosystems are major biodiversity hotspots and carbon sinks that may lose species to extinction and become carbon sources due to extreme dry or warm conditions. We investigated the seasonal patterns of high-resolution solar-induced chlorophyll fluorescence (SIF) measured by the satellite Orbiting Carbon Observatory-2 (OCO-2) across the Amazonian ecoregions to assess the area s phenology and extreme drought vulnerability. SIF is an indicator of the photosynthetic activity of chlorophyll molecules and is assumed to be directly related to gross primary production (GPP). We analyzed SIF variability in the Amazon basin during the period between September 2014 and December 2018. In particular, we focused on the SIF drought response under the extreme drought period during the strong El Nino in 20152016, as well as the 6-month drought peak period. During the drought s peak months, the SIF decreased and increased with different intensities across the ecoregions of the Amazonian moist broadleaf forest (MBF) biome. Under a high temperature, a high vapor pressure deficit, and extreme drought conditions, the SIF presented differences from 31.1% to +17.6%. Such chlorophyll activity variations have been observed in plant-level measurements of active fluorescence in plants undergoing physiological responses to water or heat stress. Thus, it is plausible that the SIF variations in the ecoregions ecosystems occurred as a result of water and heat stress, and arguably because of drought-driven vegetation mortality and collateral effects in their species composition and community structures. The SIF responses to drought at the ecoregional scale indicate that there are different levels of resilience to drought across MBF ecosystems that the currently used climate- and biome-region scales do not capture. Finally, we identified monthly SIF values of 32 ecoregions, including non-MBF biomes, which may give the first insights into the photosynthetic activity dynamics of Amazonian ecoregions.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1175/JCLI-D-16-0838.1", "year": 2017, "title": "Insights from a new high-resolution drought atlas for the Caribbean spanning 1950\u20132016", "abstract": "Abstract Climate change is expected to increase the severity and frequency of drought in the Caribbean. Understanding drought variability and its trends is therefore critical for improving resiliency and adaptation capacity of this region, as well as for assessing the dynamics and predictability of regional hydroclimate across spatial and temporal scales. This work introduces a first of its kind high-resolution drought dataset for the Caribbean region from 1950 to 2016, using monthly estimates of the self calibrating Palmer drought severity index (scPDSI), with the physically based PenmanMonteith approximation for the potential evapotranspiration. Statistically downscaled data products, including reanalysis, are employed to establish an historical baseline for characterizing drought from 1950 to the near present. Since 1950, the Caribbean has been affected by severe droughts in 197477, 1997/98, 2009/10, and 201316. Results indicate that the 201316 drought is the most severe event during the time interval analyzed in this work, which agrees with qualitative reports of many meteorological institutions across the Caribbean. Linear trends in the scPDSI show a significant drying in the study area, averaging an scPDSI change of 0.09 decade1 (p < 0.05). However, this trend is not homogenous, and significant trends toward wetter conditions in portions of the study area were observed. Results further indicate a strong influence of both tropical Pacific and North Atlantic oceans in modulating drought variability across the study domain. Finally, this effort is the first step in building high-resolution drought products for the Caribbean to be updated regularly, with the purpose of drought monitoring and eventually seasonal drought prediction.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2019JG005335", "year": 2020, "title": "Using Metabolic Energy Density Metrics to Understand Differences in", "abstract": "Terrestrial ecosystems obtain energy in the form of carbon-containing molecules. Quantifying energy acquisition and dissipation throughout an ecosystem may be useful for describing their resistance and resilience to disturbances. Three longleaf pine savannas with different vegetation composition\u2014a result of variation in soil moisture and land use legacy\u2014were used as a case study to test energy-based metrics of ecosystem metabolic function. Available energy from gross ecosystem exchange of CO2 and its dissipation into metabolic energy density (EM) and energy storage were used to identify differences in drought recovery over an 8-year period. Sites with higher plant functional diversity in the understory stored more energy and lowered their EM by ~20% when adapting to drought. In contrast, the site with greater abundance of woody understory and overstory species relied on stored energy twice as often as the more diverse sites. The absence of native understory species, due to anthropogenic legacy, prolonged ecosystem-scale drought recovery by 1 year. This study provides the tools to understand differences in site metabolic energy dynamics and has the potential to identify site characteristics that indicate greater vulnerability to disturbances. Metabolic energy density can be applied to any global ecosystem and provides a first step to describe coupled carbon and energy allocation in ecosystems, which may be used to further refine ecological theory and its management implications.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1007/S11356-020-12023-0", "year": 2021, "title": "Global drought monitoring with big geospatial datasets using Google Earth Engine", "abstract": "Drought or dryness occurs due to the accumulative effect of certain climatological and hydrological variables over a certain period. Droughts are studied through numerically computed simple or compound indices. Vegetation condition index (VCI) is used for observing the change in vegetation that causes agricultural drought. Since the land surface temperature has minimum influence from cloud contamination and humidity in the air, so the temperature condition index (TCI) is used for studying the temperature change. Dryness or wetness of soil is a major indicator for agriculture and hydrological drought and for that purpose, the index, soil moisture condition index (SMCI), is computed. The deviation of precipitation from normal is a major cause for meteorological droughts and for that purpose, precipitation condition index (PCI) is computed. The years when the indices escalated the dryness situation to severe and extreme are pointed out in this research. Furthermore, an interactive dashboard is generated in the Google Earth Engine (GEE) for users to compute the said indices using country boundary, time period, and ecological mask of their choice: Agriculture Drought Monitoring. Apart from global results, three case studies of droughts (2002 in Australia, 2013 in Brazil, and 2019 in Thailand) computed via the dashboard are discussed in detail in this research.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS12233940", "year": 2020, "title": "Multi-Temporal Analysis and Trends of the Drought Based on MODIS Data in", "abstract": "The aim of this study is to analyze the performance of the Drought Severity Index (DSI) in Romania and its validation based on other data sources (meteorological data, soil moisture content (SMC), agricultural production). Also, it is to assess the drought based on a multi-temporal analysis and trends of the DSI obtained from Terra MODIS satellite images. DSI is a standardized product based on evapotranspiration (ET) and the Normalized Difference Vegetation Index (NDVI), highlighting the differences over a certain period of time compared to the average. The study areas are located in Romania: three important agricultural lands (Oltenia Plain, Baragan Plain and Banat Plain), which have different environmental characteristics. MODIS products have been used over a period of 19 years (20012019) during the vegetation season of the agricultural crops (AprilSeptember). The results point out that those agricultural areas from the Baragan Plain and Oltenia Plain were more affected by drought than those from Banat Plain, especially in the years 2002, 2007 and 2012. Also, the drought intensity and the agricultural surfaces affected by drought decreased in the first part of the vegetation season (MarchMay) and increased in the last part (AugustSeptember) in all three study areas analyzed. All these results are confirmed by those of the Standardized Precipitation Evapotranspiration Index (SPEI) and Soil Moisture Anomaly (SMA) indices.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2022GL098700", "year": 2022, "title": "Drought Legacy in Sub\u2010Seasonal Vegetation State and Sensitivity to Climate Over the Northern Hemisphere", "abstract": "Droughts affect ecosystems at multiple time scales, but their sub-seasonal legacy effects on vegetation activity remain unclear. Combining the satellite-based enhanced vegetation index MODIS EVI with a novel location-specific definition of the growing season, we quantify drought impacts on sub-seasonal vegetation activity and the subsequent recovery in the Northern Hemisphere. Drought legacy effects are quantified as changes in post-drought greenness and sensitivity to climate. We find that greenness losses under severe drought are partially compensated by a \u223c+5% greening within 2-6 growing-season months following the droughts, both in woody and herbaceous vegetation but at different timings. In addition, post-drought sensitivity of herbaceous vegetation to hydrological conditions increases noticeably at high latitudes compared with the local normal conditions, regardless of the choice of drought time scales. In general, the legacy effects on sensitivity are larger in herbaceous vegetation than in woody vegetation.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/ATMOS12020201", "year": 2021, "title": "Climate Variability of Atmospheric Rivers and Droughts over the West", "abstract": "Water resources are crucial to the livelihood and sustainability of the general public across the western United States. This study covers the timespan of both the third driest drought in Californian history between 2012 and 2015 as well as the extreme atmospheric river year in 20162017. The evaluation of vertical moisture profiles using Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) Radio Occultation (RO) data, National Centers for Environmental Prediction (NCEP)/National Center for Atmospheric Research (NCAR) Reanalysis of 500 hPa geopotential heights, 1000500 hPa thickness, Optimum Interpolation (OI) Sea Surface Temperature (SST), NOAA/NDBC buoy data, and NASA, MEaSUREs, Gridded Sea Surface Height Anomalies (SSHA) were performed. The daily COSMIC time evolution from 2006 through 2015 showed a flat to slightly upward trend of both temperature and water vapor profiles through the entirety of the western US drought. Subsequently, a significant increase of temperatures and water vapor were recorded in early 2016 before the extreme Atmospheric River (AR) season of 20162017. The quantitative analyses suggest that warmer SST and higher SSHA lead to an increase of heat fluxes from the ocean into the troposphere, which forces thickness changes and thus the position of troughs in the geopotential height field changes afterwards, consequently pushing the trough eastward over the Pacific Northwest and potentially leading to an active AR year in the western US. It appears that regional COSMIC RO moisture profiles, seasonal SST, and SLH anomalies may serve as a precursor for seasonal or sub-seasonal precipitation outlook along the western US.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/ACP-22-13303-2022", "year": 2022, "title": "Interactive biogenic emissions and drought stress effects on atmospheric composition in NASA GISS ModelE", "abstract": "Abstract. Drought is a hydroclimatic extreme that causes perturbations to the terrestrial biosphere and acts as a stressor on vegetation, affecting emissions patterns. During severe drought, isoprene emissions are reduced. In this paper, we focus on capturing this reduction signal by implementing a new percentile isoprene drought stress (yd) algorithm in NASA GISS ModelE based on the MEGAN3 (Model of Emissions of Gases and Aerosols from Nature Version 3) approach as a function of a photosynthetic parameter (Vc,max) and water stress (). Four global transient simulations from 20032013 are used to demonstrate the effect without yd (Default_ModelE) and with online yd (DroughtStress_ModelE). DroughtStress_ModelE is evaluated against the observed isoprene measurements at the Missouri Ozarks AmeriFlux (MOFLUX) site during the 2012 severe drought where improvements in the correlation coefficient indicate it is a suitable drought stress parameterization to capture the reduction signal during severe drought. The application of yd globally leads to a decadal average reduction of 2.7 %, which is equivalent to 14.6 Tg yr1 of isoprene. The changes have larger impacts in regions such as the southeastern US. DroughtStress_ModelE is validated using the satellite HCHO column from the Ozone Monitoring Instrument (OMI) and surface O3 observations across regions of the US to examine the effect of drought on atmospheric composition. It was found that the inclusion of isoprene drought stress reduced the overestimation of HCHO in Default_ModelE during the 2007 and 2011 southeastern US droughts and led to improvements in simulated O3 during drought periods. We conclude that isoprene drought stress should be tuned on a model-by-model basis because the variables used in the parameterization responses are relative to the land surface model hydrology scheme (LSM) and the effects of yd application could be larger than seen here due to ModelE not having large biases of isoprene during severe drought.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1088/1748-9326/ABACFA", "year": 2020, "title": "A statistical approach towards defining national-scale meteorological droughts in India using crop data", "abstract": "Abstract\r\n In recent years, several drought indices have been developed and used to monitor local to regional scale droughts on various temporal scales. However, to our knowledge, these indices do not possess generalized criteria to define a threshold in which to declare a national-scale drought. We present a statistical methodology to identify national-scale meteorological drought years in India. We implement a Superposed Epoch Analysis and bootstrap analysis to estimate annual cereal crop production losses as a result of widespread meteorological drought events. For this purpose, the meteorological definition of drought based on the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI), in combination with the countrys cropland area and cereal crops production, is used. The results demonstrate that a national-scale meteorological drought is defined if approximately 19% or more of Indias cropland is affected by meteorological drought (SPI3 and SPEI3 equal to or less than 1.00) throughout the monsoon season (JuneSeptember). According to this analysis, depending on the indicator data used, a total of 18to 20 national-scale meteorological droughts were identified in India during 19642015, causing a 3.61% to 3.93% composite decrease in cereal crops production. The years which were commonly identified as national scale meteorological droughts over cropland by using different approaches are 1965, 1972, 1987, 2002, and 2009. A similar statistical approach can also be used to define drought thresholds at various spatial scales using the drought indices most applicable to the purpose and scale of study.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.7298/KBTT-6J68", "year": 2021, "title": "Essays in Environmental and Development Economics", "abstract": "This dissertation lies at the intersection of environmental economics and development economics. It includes three essays that empirically examine the effects of climate change and extreme weather events on agriculture in both developed and developing countries.The first essay explores how the choice of weather data sets could affect estimates of climate change impacts. A large body of empirical literature finds that high temperatures are detrimental to a wide range of economic outcomes. These effects are often identified from the within-location temporal variation in exposure to the extreme right tail of the temperature distribution. Here, we document large discrepancies in exposure to extreme temperatures across six high-resolution gridded weather data sets in the US, where weather data is considered to be of high quality. We explore and illustrate the consequences of these data discrepancies in the estimation of potential climate change impacts on agriculture. We find that most climate change impacts based on different climate data sets are not statistically different from each other. Yet, the choice of the underlying weather data set can account for up to 48 percent of estimated warming damages on US crop yields. These findings highlight an important, but generally unrecognized, source of uncertainty in estimates of climate change impacts and the need for more systematic intercomparisons of widely used geospatial data sets in environmental social sciences. In the second essay, we estimate the impact of self-reported occurrences of droughts and floods on crop and livestock net income in Sub-Saharan Africa during the period 20092016. Based on a pooled data set for five countries, we find robust negative and heterogeneous impacts of droughts and floods across different levels of irrigation, poverty, and agricultural diversification, including reductions of net crop income by 34 percent and 61 percent due to droughts and floods, respectively. The study also confirms the importance of poverty alleviation and agricultural diversification to cope with the adverse effects of droughts and floods. The third essay studies the effects of droughts and floods on agricultural livelihoods in Zambia. The adverse effects of weather extremes produce widespread damage and cause severe alterations in the normal functioning of household agricultural production in Zambia. The intensity and frequency of extreme weather events, such as droughts and floods, are expected to increase due to climate change. Coupled with high poverty levels and limited institutional capacity, the country is highly vulnerable to the impact of extreme events. We quantify the effects of economic diversification on the agricultural productivity of poor farm households with a skew-normal regression approach while accounting for drought and flood shocks. Our analysis finds that economic diversification is a strategy to increase agricultural productivity and mitigate the adverse impact of droughts and floods on agricultural households. The results also support the countrys policies to encourage hybrid maize production and to provide crop seeds and fertilizers to poor farmers. This paper provides a framework to plan and inform interventions to enhance household economic resilience to weather shocks through agricultural diversification in Zambia and other countries.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.CROPRO.2018.07.013", "year": 2018, "title": "Evaluating a generic drought index as a predictive tool for aflatoxin contamination of corn: From plot to regional level", "abstract": "Corn (Zea mays L.) kernel infection by Aspergillus flavus and subsequent aflatoxin accumulation in grain can have a deleterious effect on both humans and animals that consume contaminated grain. Predicting the aflatoxin risk is challenging due to complex interactions of biotic and abiotic stress factors that govern and exacerbate the phenomenon. The goal of this study was to determine whether a drought index could be used to predict the risk for pre-harvest aflatoxin contamination in corn. Risk assessment was approached at: 1) field (plot) level with data obtained from an in-field controlled experiment (Mississippi study), and 2) state level, where corn fields were sampled at a county level (Georgia study). The data used for this study consisted of historical records on aflatoxin contamination collected over thirteen growing seasons from 2000 to 2011, 2013, and 2014 at Mississippi State, Mississippi (1), and from random corn fields in 53 counties across Georgia between 1977 and 2004 (2). A controlled experiment was conducted at Mississippi with two soil types (a Leeper silty clay loam and a Myatt loam), and three commercial hybrids characterized by different susceptibility levels to aflatoxin contamination. The Agricultural Reference Index for Drought (ARID), a generic drought index for calculating drought on daily basis was evaluated as an aflatoxin risk prediction tool. Mid-silk day was selected to split each growing season into two time periods, which were further divided into positive and negative weeks representing weeks after and before mid-silk, respectively. Weekly ARID factors were calculated for all periods to evaluate the in-season alterations in aflatoxin risk. In both studies, multiple logistic regression models were used to predict aflatoxin risk as a function of the weekly ARID values. In Mississippi, risk level changes were additionally tested according to soil type and corn hybrid aflatoxin susceptibility. The United States Food and Drug Administration restricts corn grain consumption by humans and young animals if the contamination level is above 20 \u03bcg/kg; thus, this threshold (20 \u03bcg/kg) was selected to develop a binary dependent variable for the logistic model from the raw aflatoxin data. The results revealed that ARID might be used as a predictive tool to assess aflatoxin risk, soil type and hybrid susceptibility to aflatoxin contamination were statistically significant independent factors, and there are critical week windows during the growing season when changes in drought conditions affect the likelihood for aflatoxin contamination. These findings can be used to minimize risk by adapting site-specific management strategies such as triggering irrigation during critical risk weeks, selecting the most appropriate hybrid for a given site/location based on soil type, and determining optimum harvest date.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/METEOROLOGY1020009", "year": 2022, "title": "Trends in the Frequency of Water and Heat Stress in Mid-Latitude North America since 1980", "abstract": "The water-energy balance of many mid-latitude watersheds has been changing in recent decades due to global warming. These changes manifest themselves over both long timescales (e.g., hydrologic drought) and short timescales (e.g., agricultural drought) and may be ameliorated or exacerbated by vegetative response. We apply a Budyko framework to assess short-term response to long-term trends in water and heat stress (HS) across mid-latitude North America. Using high-resolution meteorological data and streamflow records, we calculate the frequency of HS every year since 1980 for every gaged watershed with adequate data (n = 1528). We find that HS has become more frequent in most watersheds in the western US, New England, and southeastern Canada. However, we find that HS has become less frequent in the Midwest and the relatively humid eastern US. By assessing the relationship between trends in HS frequency and proximate forcing variables (annual PPT, annual streamflow, minimum and maximum daily temperatures, actual evapotranspiration, and potential evapotranspiration), we find that these trends in HS frequency are primarily driven by meteorological forcings rather than vegetative response. Finally, we contextualize our findings within the Budyko framework, which assumes a landscape in equilibrium with its climate, with the implication that these trends in HS are only likely to be realized after local vegetation has adapted to new meteorological norms.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 12, "name": "Heat" } ] }, { "doi": "10.5194/NHESS-21-995-2021", "year": 2021, "title": "Drought impact in the Bolivian Altiplano agriculture associated with the El Ni\u00f1o\u2013Southern Oscillation using satellite imagery data", "abstract": "Abstract. Drought is a major natural hazard in the Bolivian Altiplano that causes large agricultural losses. However, the drought effect on agriculture varies largely on a local scale due to diverse factors such as climatological and hydrological conditions, sensitivity of crop yield to water stress, and crop phenological stage among others. To improve the knowledge of drought impact on agriculture, this study aims to classify drought severity using vegetation and land surface temperature data, analyse the relationship between drought and climate anomalies, and examine the spatio-temporal variability of drought using vegetation and climate data. Empirical data for drought assessment purposes in this area are scarce and spatially unevenly distributed. Due to these limitations we used vegetation, land surface temperature (LST), precipitation derived from satellite imagery, and gridded air temperature data products. Initially, we tested the performance of satellite precipitation and gridded air temperature data on a local level. Then, the normalized difference vegetation index (NDVI) and LST were used to classify drought events associated with past El NinoSouthern Oscillation (ENSO) phases. It was found that the most severe drought events generally occur during a positive ENSO phase (El Nino years). In addition, we found that a decrease in vegetation is mainly driven by low precipitation and high temperature, and we identified areas where agricultural losses will be most pronounced under such conditions. The results show that droughts can be monitored using satellite imagery data when ground data are scarce or of poor data quality. The results can be especially beneficial for emergency response operations and for enabling a proactive approach to disaster risk management against droughts.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.AGRFORMET.2006.03.019", "year": 2006, "title": "Drought constraints on transpiration and canopy conductance in mature aspen and jack pine stands", "abstract": "Half-hourly mean values of transpiration measured by eddy covariance over the course of six growing seasons in two boreal forest sites were used to develop stand-level relationships between transpiration and soil water content. The two sites were an aspen site on fine-textured soil and over five growing seasons for a jack pine site on coarse-textured soil in Saskatchewan, Canada. About half of the data record covered a multi-year drought that was more severe at the aspen site than the jack pine site. Measurements of transpiration and environmental variables were used to adjust a transpiration model to each site, with environmental variables retained in the model based on their capacity to improve the model adjustment. The model was also used to produce estimates of maximum canopy conductance (g cMAX). The fit of the model to the aspen half-hourly transpiration is better than to the jack pine data (r 2 of 0.86 versus 0.60). Relative soil water content explains more of the variability in half-hourly transpiration at the aspen site (46%) than at the jack pine site (10%). The relationships between transpiration and environmental variables are stable throughout the drought suggesting an absence of acclimation. Published soil water modifier curves for loamy clay soils compare well with the modifier function we obtained for a similar soil at the aspen site, but the agreement between the published curve and our curve is poor for the sandy soil of the jack pine site. Values of g cMAX computed at the half-hourly scale are greater at the aspen site (14.3 mm s -1) than at the jack pine site (10.2 mm s -1), but we hypothesize that the coarse soil and perennially lower water content of the jack pine site may cause this difference. Finally, we also present values of g cMAX computed at the daily and monthly scales for use in models that operate at these time steps.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1038/S41467-018-05668-6", "year": 2018, "title": "Post-drought decline of the Amazon carbon sink", "abstract": "Amazon forests have experienced frequent and severe droughts in the past two decades. However, little is known about the large-scale legacy of droughts on carbon stocks and dynamics of forests. Using systematic sampling of forest structure measured by LiDAR waveforms from 2003 to 2008, here we show a significant loss of carbon over the entire Amazon basin at a rate of 0.3 0.2 (95% CI) PgC yr1 after the 2005 mega-drought, which continued persistently over the next 3 years (20052008). The changes in forest structure, captured by average LiDAR forest height and converted to above ground biomass carbon density, show an average loss of 2.35 1.80 MgC ha1 a year after (2006) in the epicenter of the drought. With more frequent droughts expected in future, forests of Amazon may lose their role as a robust sink of carbon, leading to a significant positive climate feedback and exacerbating warming trends.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1080/15481603.2021.2012370", "year": 2022, "title": "Development of earth observational diagnostic drought prediction model for regional error calibration: A case study on agricultural drought in Kyrgyzstan", "abstract": "Drought is a natural disaster that occurs globally and is a main trigger of secondary environmental and socio-economic damages, such as food insecurity, land degradation, and sand-dust storms. As climate change is being accelerated by human activities and environmental changes, both the severity and uncertainties of drought are increasing. In this study, a diagnostic drought prediction model (DDPM) was developed to reduce the uncertainties caused by environmental diversity at the regional level in Kyrgyzstan, by predicting drought with meteorological forecasts and satellite image diagnosis. The DDPM starts with applying a prognostic drought prediction model (PDPM) to 1) estimate future agricultural drought by explaining its relationship with the standardized precipitation index (SPI), an accumulated precipitation anomaly, and 2) compensate for regional variances, which were not reflected sufficiently in the PDPM, by taking advantage of preciseness in the time-series vegetation condition index (VCI), a satellite-based index representing land surface conditions. Comparing the prediction results with the monitored VCI from June to August, it was found that the DDPM outperformed the PDPM, which exploits only meteorological data, in both spatiotemporal and spatial accuracy. In particular, for June to August, respectively, the results of the DDPM (coefficient of determination [R2] = 0.27, 0.36, and 0.4; root mean squared error [RMSE] = 0.16, 0.13, and 0.13) were more effective in explaining the spatial details of drought severity on a regional scale than those of the PDPM (R2 = 0.09, 0.10, and 0.11; RMSE = 0.17, 0.15, and 0.16). The DDPM revealed the possibility of advanced drought assessment by integrating the earth observation big data comprising meteorological and satellite data. In particular, the advantage of data fusion is expected to be maximized in areas with high land surface heterogeneity or sparse weather stations by providing observational feedback to the PDPM. This research is anticipated to support policymakers and technical officials in establishing effective policies, action plans, and disaster early warning systems to reduce disaster risk and prevent environmental and socio-economic damage.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1175/JHM-D-21-0237.1", "year": 2022, "title": "How predictable is short-term drought in the northeastern United States?", "abstract": "Abstract We investigated the predictability (forecast skill) of short-term droughts using the Palmer Drought Severity Index (PDSI). We incorporated a sophisticated data training (of decadal range) to evaluate the improvement of forecast skill of short-term droughts (3-month). We investigated whether the data training of the synthetic North American Multi-Model Ensemble (NMME) climate has some influence on enhancing short-term drought predictability. The central elements are the merged information among PDSI and NMME with two post-processing techniques. (1) The bias correction spatial disaggregation (BC-SD) method improves spatial resolution by using a refined soil information introduced in the available water capacity of the PDSI calculation to assess water deficit that better estimates drought variability. (2) The ensemble model output statistic (EMOS) approach includes systematically trained decadal information of the multi model-ensemble simulations. Skill of drought forecasting improves when using EMOS, but BC-SD does not increase the forecast skill when compared with an analysis using BC (low spatial resolution). This study suggests that predictability forecast of drought (PDSI) can be extended without any change in the core dynamics of the model but instead by using the sophisticated EMOS post-processing technique. We pointed out that using NMME without any postprocessing is of limited use in the suite of model variations of the NMME, at least for the US Northeast. From our analysis, 1-month is the most extended range we should expect, which is below the range of the seasonal scale presented with EMOS (2-month). Thus, we propose a new design of drought forecasts that explicitly includes the multi-model ensemble signal.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JHYDROL.2018.05.069", "year": 2018, "title": "Groundwater recharge indicator as tool for decision makers to increase socio-hydrological resilience to seasonal drought", "abstract": "Communities in regions with seasonal rainfall face annual dry seasons, during which water shortages and conflicts between different water use sectors may erupt. These difficulties increase following wet seasons with low rainfall, such as in relation to El Nino events in the wet-dry tropics of Central America. Hydrologic data are typically scarce in this region, making the development of drought adaptation strategies challenging. Many communities in the region depend on groundwater as their primary water source. For instance in the Province of Guanacaste in Costa Rica, groundwater supplied 78% of the total domestic water demand in 2015 and groundwater recharge from the wet season provides the primary water supply for the subsequent dry season. In this research we present a groundwater recharge indicator that can support water managers in preparing for seasonal droughts. We developed this tool for an aquifer in northwestern Costa Rica where we conducted hydrological monitoring of streams and groundwater levels for 2.5 years, obtained further hydrological data (groundwater levels from 2005 to 2016), and worked with communities to assemble water use data. We combined these datasets in a hydrologic model (the Water Evaluation And Planning system, WEAP) and modelled groundwater recharge from 2005 to 2016, permitting a characterization of the relationship between rainfall and groundwater recharge. The groundwater recharge indicator is based on this relationship, and allows estimating total groundwater recharge for a wet season from cumulative rainfall measured to date. The indicator permits water managers to assess if the current year will likely fall into a low recharge category prior to the end of the wet season. This information can then be used to trigger short-term adaptation strategies with the goal to bank groundwater while surface water sources are still available in the wet season. This indicator-based tool was refined through feedback provided in local stakeholder workshops. We also assessed the overall accuracy of predicting end-of-wet-season groundwater recharge with cumulative rainfall to date, and found that after the first 23 months of the wet season, prediction accuracies are high, leaving 56 months of wet season to respond adaptively to the prediction. The indicator can help water managers to plan ahead, and communicate the need for water conservation (demand management) and consideration of other water sources such as rain and surface water (supply management). This idea is transferable to other communities in regions with seasonal rainfall, and can support decision makers in increasing the socio-hydrological resilience of communities to seasonal droughts.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1109/AGRO-GEOINFORMATICS.2018.8476013", "year": 2018, "title": "Drought monitoring over the Northeast China Using GRACE satellite data from 2002 to 2016", "abstract": "Drought is one of the most common natural disasters in the world. The frequent occurrence and long-term persistence of drought will result in huge losses in industrial and agricultural production. Understanding and quantification of the time and spatial dynamic patterns of drought, including the occurrence, duration and intensity, are the primary goals of the agriculture drought monitoring and yield forecasting in the agricultural region in Northeast China. Fundamentally, drought monitors rely on satellite-gauge precipitation data and temperature, yet is also depends on underground water storage, evapotranspiration and runoff. Since 2002, NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission provide a revolutionary approach to view the water stored in soil, track the movement of water and retrieve the total water storage (TWS) via weight. And the TWS change can provide the regional information of precipitation, evapotranspiration, and surface and subsurface runoff. In this study, the GRACE TWS anomaly will be revealed to Northeast China to characterize more objective identification of drought for 157 months climatology (from April 2002 to December 2016). Comparing with the drought incidents from 2002 to 2016 in the Northeast China, the result shows that the trends of GRACE TWS with months can depict the temporal and spatial characteristic of drought in the study area. According to the negative GRACE terrestrial water storage anomalies (TWSA), which can represent storage deficits, we find that severe drought happened in western part of the study area in 2003, and southern part of the study area in 2007 and 2011. The April-May average GRACE TWS noted the spring drought occurred in most part of study area in 2003, 2009, 2011 and 2012. The significant decreases of TWS from May 2007 to June 2008 reveled by GRACE TWS lead to a serious drought conditions. The five-month averages of GRACE TWS from June to October were computed in each year, and deficit during 2014 lead to an agricultural drought and crop production loss in Liaoning and Jilin provinces. However, GRACE TWS changes show no one-to-one relationship with precipitation, as the precipitation is not the primary source of TWS changes. The present result demonstrates that GRACE TWS as referenced data is capable of identify and mapping drought in the Northeast China. It will help better understand the cause of drought, and observe the occurrence, trends and spatiotemporal characteristics of drought. It would be valuable for regional water management.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1111/J.1365-2435.2009.01683.X", "year": 2010, "title": "Impacts of experimentally imposed drought on leaf respiration and morphology in an Amazon rain forest", "abstract": "Summary 1. The Amazon region may experience increasing moisture limitation over this century. Leaf dark respiration (R) is a key component of the Amazon rain forest carbon (C) cycle, but relatively little is known about its sensitivity to drought. 2. Here, we present measurements of R standardized to 25 \u00b0C and leaf morphology from different canopy heights over 5 years at a rain forest subject to a large\u2011scale through\u2011fall reduction (TFR) experiment, and nearby, unmodified Control forest, at the Caxiuan\u00e3 reserve in the eastern Amazon. 3. In all five post\u2011treatment measurement campaigns, mean R at 25 \u00b0C was elevated in the TFR forest compared to the Control forest experiencing normal rainfall. After 5 years of the TFR treatment, R per unit leaf area and mass had increased by 65% and 42%, respectively, relative to pre\u2011treatment means. In contrast, leaf area index (L) in the TFR forest was consistently lower than the Control, falling by 23% compared to the pre\u2011treatment mean, largely because of a decline in specific leaf area (S). 4. The consistent and significant effects of the TFR treatment on R, L and S suggest that severe drought events in the Amazon, of the kind that may occur more frequently in future, could cause a substantial increase in canopy carbon dioxide emissions from this ecosystem to the atmosphere.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2021GL093777", "year": 2021, "title": "Human influence on the increasing drought risk over Southeast Asian monsoon region", "abstract": "Southeast Asian monsoon region is regularly stricken by drought, but less attention is paid due to its slow-onset and less visual impact. This study investigated the observed drought changes over Southeast Asian monsoon region and impacts of anthropogenic forcing using the Coupled Model Intercomparison Project Phase 6 models. We revealed an increasing drought risk for 1951-2018 due to more frequent and wide-spread droughts. The influence of anthropogenic forcing is successfully detected, which has increased the likelihood of the extreme droughts in historical simulation by reducing precipitation and enhancing evapotranspiration. The time of emergence of anthropogenic forcing in extreme drought occurrence and affected area occurs around the 1960s. The future projected severe and extreme drought risks are still beyond natural only forced changes under all scenarios. Our findings demonstrate a robust impact of anthropogenic forcing on drought risk over Southeast Asia, and highlight the importance of future pathway choice.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/SU11246897", "year": 2019, "title": "Analysis of the Drought Mitigated Mechanism in Terraced Paddy Fields", "abstract": "Food security is often threatened by droughts during rice production. Although most of the rice is produced in lowland or irrigated wet rice fields, terraced paddy fields are important in the rice production system in island or mountainous countries. With the intensifying frequency of El Nino periods in recent decades, there has been a risk of droughts in terraced paddy areas. To mitigate drought, remote sensing data analysis could be an efficient and reliable tool for obtaining scarce ground monitoring data. In this study, crop water stress index (CWSI) and temperature vegetation dryness index (TVDI) were applied to evaluate the drought intensity, and hydrological monitoring data was provided as a support for the evaluation. The results indicated that droughts normally occurred during the dry season, and intensified during El Nino periods. CWSI and TVDI were visible to predict drought occurrences in the watershed area. TVDI overestimated the drought inside Keduang watershed compared to CWSI because of the complex condition of the terraced paddy area, including the hydrology in this area. The complex topography, high groundwater table, and continuous plot-to-plot irrigation helped to maintain the water availability and mitigated the drought impact for rice production in the studied terraced paddy field.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1038/NCOMMS14196", "year": 2017, "title": "Climate change reduces extent of temperate drylands and intensifies drought in deep soils", "abstract": "Drylands cover 40% of the global terrestrial surface and provide important ecosystem services. While drylands as a whole are expected to increase in extent and aridity in coming decades, temperature and precipitation forecasts vary by latitude and geographic region suggesting different trajectories for tropical, subtropical, and temperate drylands. Uncertainty in the future of tropical and subtropical drylands is well constrained, whereas soil moisture and ecological droughts, which drive vegetation productivity and composition, remain poorly understood in temperate drylands. Here we show that, over the twenty first century, temperate drylands may contract by a third, primarily converting to subtropical drylands, and that deep soil layers could be increasingly dry during the growing season. These changes imply major shifts in vegetation and ecosystem service delivery. Our results illustrate the importance of appropriate drought measures and, as a global study that focuses on temperate drylands, highlight a distinct fate for these highly populated areas.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JHYDROL.2021.126868", "year": 2021, "title": "A comprehensive assessment of water storage dynamics and hydroclimatic extremes in the Chao Phraya River Basin during 2002\u20132020", "abstract": "A holistic assessment of the hydroclimatic extremes, which have caused tremendous environmental, societal, and economic losses globally, is imperative for the highly vulnerable Chao Phraya River Basin. In this study, the water storage dynamics and extremes in the basin during 20022020 were quantified, for the first time, using GRACE (Follow-On) based terrestrial water storage anomaly (TWSA) with the help of a novel artificial neural network-based model for the data gap filling. TWSA showed a linear trend of 1.12 0.05 cm yr1 (equivalent to a volumetric trend of 1.79 0.08 km3 yr1) in the basin, and segregation of the constituent components of TWS revealed that the groundwater storage is a significant contributor (45%) to TWS with a linear trend of 0.51 0.06 cm yr1 (-0.82 0.10 km3 yr1) followed by surface water storage (i,e., cumulative of the water storage in the reservoirs, flood inundation, and rivers) (36%) and soil moisture storage (19%). The hydroclimatic extremes detected in TWSA are primarily triggered by the variations in precipitation during the monsoon season (May to October) and further amplified by the subsequent water storage and abstraction. TWSA attained a maximum of 42.86 cm in October 2011 during severe floods of 2011 (~95% increase in net precipitation during 2010 and 2011) and a minimum of 31.81 cm during the drought of May 2020 (~82% decrease in net precipitation during 2019 and 2020). All other flood and drought events in some years, e.g., 2006, 2010, 2015, 2016, are also well recorded in TWSA, albeit with a lag time of up to a maximum of two months from precipitation. Further, the basins increasing potential of severe drought, as assessed by the effective water-storage-based novel drought potential index (DPI), underscored the need for multifaceted water management essentially focused on the demand side rather than the supply side in the basin. The proposed framework can be utilized for policymaking for adequate and equitable water allocation, developing the early warning systems for the droughts and floods, and employing the optimal adaptation measures in the Chao Phraya River Basin and other data-scarce river basins globally.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS13101990", "year": 2021, "title": "Ambiguous agricultural drought: Characterising soil moisture and vegetation droughts in europe from earth observation", "abstract": "Long-lasting precipitation deficits or heat waves can induce agricultural droughts, which are generally defined as soil moisture deficits that are severe enough to negatively impact vegetation. However, during short soil moisture drought events, the vegetation is not always negatively affected and sometimes even thrives. Due to this duality in agricultural drought impacts, the term agricultural drought is ambiguous. Using the ESAs remotely sensed CCI surface soil moisture estimates and MODIS NDVI vegetation greenness data, we show that, in major European droughts over the past two decades, asynchronies and discrepancies occurred between the surface soil moisture and vegetation droughts. A clear delay is visible between the onset of soil moisture drought and vegetation drought, with correlations generally peaking at the end of the growing season. At lower latitudes, correlations peaked earlier in the season, likely due to an earlier onset of water limited conditions. In certain cases, the vegetation showed a positive anomaly, even during soil moisture drought events. As a result, using the term agricultural drought instead of soil moisture or vegetation drought, could lead to the misclassification of drought events and false drought alarms. We argue that soil moisture and vegetation drought should be considered separately.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/F13060921", "year": 2022, "title": "Two Centuries of Drought History in the Center of Chihuahua, Mexico", "abstract": "Droughts are a climatic phenomenon with local, regional, and large-scale repercussions. Historical knowledge of droughts generated by modeled data allows the development of more accurate climate reconstructions to propose better approaches for the management of hydric resources. The objective of this research was to evaluate the association of precipitation and temperature with data from the NLDAS-002 to develop a reconstruction of droughts in the center of Chihuahua, Mexico using the SPEI from tree rings. We also identified the influence of oceanatmospheric phenomena on the reconstructed drought index. The best association among chronologies was obtained with the earlywood band and accumulated seasonal precipitation from November of the previous year to June of the current year (r = 0.82, p < 0.05) and for temperature from January to July (r = 0.81, p < 0.05). The reconstructed drought index extended from 1775 to 2017 (243 years), where seven extreme drought events were identified. We found significant correlations between the reconstructed Standardized Precipitation Evapotranspiration Index and the Pacific Decadal Oscillation (r = 0.46, p < 0.05), Atlantic Multidecadal Oscillation (r = 0.34, p < 0.05), Multivariate El Nino Southern Oscillation Index (r = 0.29, p < 0.05), and Southern Oscillation Index (r = 0.22, p < 0.05). The historical reconstruction of hydroclimatology in the center of Chihuahua is important for planning a long-term assessment and for the management of water resources shared by Mexico and the United States.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/ISPRS-ARCHIVES-XLIII-B3-2022-1173-2022", "year": 2022, "title": "DROUGHT PATTERN ASSESSMENT OVER MARATHWADA, INDIA THROUGH THE DEVELOPMENT OF MULTIVARIATE ADVANCE DROUGHT RESPONSE INDEX", "abstract": "Abstract. The intensity and frequency with which recent drought events are occurring has made management of food and water a challenge. The situation in Indian subcontinent is no difference. The presented study takes inspiration from such problems to propose a remote sensing based multivariate advance drought response index (ADRI). The proposed multivariate index takes into consideration long term conditions of precipitation, normalized difference vegetation index (NDVI), brightness temperature and soil moisture in a linear way for 8-day drought assessment over drought affected Marathwada region, Maharashtra, India. A value of 33 corresponding to ADRI was found to be normal condition over two decades which corresponds to normal vegetation condition index (VCI) value of 51.1 and 54.2. The last 7 years shows a consistent pattern in the change of regional ADRI values which suggests the years in which agricultural assistance is needed over the region. Drought over the region is found to shift from central to eastern and northern regions in the last 5 years. Temporal analysis for the duration suggests up to 5 percent of the area of Marathwada has been facing severe drought conditions over the last decade while up to 70 percent of the area is experience below normal conditions with varying intensities of water stress. The districts of Latur, Parbhani, Hingoli and Nanded which are downstream river Godavari have been affected the most due to large percentage of land being under agriculture.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5121/IJDKP.2017.7401", "year": 2017, "title": "Data mining attribute selection approach for drought modeling: A case study for Greater Horn of Africa", "abstract": "The objectives of this paper were to 1) develop an empirical method for selecting relevant attributes for modelling drought, and 2) select the most relevant attribute for drought modelling and predictions in the Greater Horn of Africa (GHA). Twenty four attributes from different domain areas were used for this experimental analysis. Two attribute selection algorithms were used for the current study: Principal Component Analysis (PCA) and correlation-based attribute selection (CAS). Using the PCA and CAS algorithms, the 24 attributes were ranked by their merit value. Accordingly, 15 attributes were selected for modelling drought in GHA. The average merit values for the selected attributes ranged from 0.5 to 0.9. Future research may evaluate the developed methodology using relevant classification techniques and quantify the actual information gain from the developed approach.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/NHESS-21-2829-2021", "year": 2021, "title": "Global flood exposure from different sized rivers", "abstract": "Abstract. There is now a wealth of data to calculate global flood exposure. Available datasets differ in detail and representation of both global population distribution and global flood hazard. Previous studies of global flood risk have used datasets interchangeably without addressing the impacts using different datasets could have on exposure estimates. By calculating flood exposure to different sized rivers using a model-independent geomorphological river flood susceptibility map (RFSM), we show that limits placed on the size of river represented in global flood models result in global flood exposure estimates that differ by more than a factor of 2. The choice of population dataset is found to be equally important and can have enormous impacts on national flood exposure estimates. Up-to-date, high-resolution population data are vital for accurately representing exposure to smaller rivers and will be key in improving the global flood risk picture. Our results inform the appropriate application of these datasets and where further development and research are needed.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.3389/FENVS.2019.00127", "year": 2019, "title": "The value of near real-time earth observations for improved flood disaster response", "abstract": "Information is a critical resource in disaster response scenarios. Data regarding the geographic extent, severity, and socioeconomic impacts of a disaster event can help guide emergency responders and relief operations, particularly when delivered within hours of data acquisition. Information from remote observations provides a valuable tool for assessing conditions on the ground more quickly and efficiently. Here, we evaluate the social value of a near real-time flood impact system using a disaster response case study, and quantify the Value of Information (VOI) of satellite-based observations for rapid response using a hypothetical flooding disaster in Bangkok, Thailand. MODIS imagery from NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) system is used to produce operational estimates of inundation depths and economic damages. These rapid Earth observations are coupled with a decision-analytical model to inform decisions on emergency vehicle routing. Emergency response times from vehicles routed using flood damage data are compared with baseline routes without the benefit of advance information on road conditions. Our results illustrate how the application of near real-time Earth observations can improve the response time and reduce potential encounters with flood hazards when compared with baseline routing strategies. Results indicate a potential significant economic benefit (i.e., millions of dollars) from applying near real-time Earth observations for improved flood disaster response and management.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.46660/IJEEG.VOL11.ISS1.2020.419", "year": 2020, "title": "Using Remote Sensing for Identifying Suitable Areas for Flood Shelter: A Case Study of Thatta, Sindh Pakistan", "abstract": "The most recurring type of disaster in the world these days is flood because of the spread and extent of its effect on people, among all-natural disasters of the world. Human activities have paved the way for many of these flood behavior to change as they used to be in the past. Pakistan experienced one of the most devastating natural disasters in its history all across the country in 2010, but Thatta district in southern part got severely affected during this flood. For the research, a simple yet efficient methodology Normalized Difference Vegetation Index (NDVI) by using remote sensing images for identifying flood hazard areas was utilized. Geographic Information Systems (GIS) helps in finding shelter areas with a minimum effect of floods. It is essential to realize the importance of mapped results in consideration of manual flood management in future. The method used in this study is robust enough to explain the flood hazard for suggesting suitable shelter sites in case of flooding events. This would help disaster management bodies and other related agencies to formulate the development plans while keeping the hazard areas, which are unsuitable for development due to flood risk in the future.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.DIB.2022.108268", "year": 2022, "title": "Datasets of land use change and flood dynamics in the vietnamese mekong delta", "abstract": "This paper compiles the data associated with a research article published in STOTEN [1]. The data set represents figures, tables, and images illustrating the temporal and spatial distribution of land use and flood dynamics from 2000 to 2020 in the Vietnamese Mekong Delta (VMD). The MODIS imageries were freely accessed online via the NASA website [2] and processed to land use and flood maps based on the algorithms by Sakamoto et al. [3,4]. The MODIS products show a high validation with statistical data and radar satellites [1]. The datasets of flood map and land use, therefore, are available to scientists, engineers, and policy-makers in agricultural management associated with flood management in the VMD. They could be used for policy settings, household livelihood assessment as well as other economic analyses for the VMD region due to the change of land use and flooding dynamics.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/NHESS-19-2635-2019", "year": 2019, "title": "Meteorological conditions leading to the 2015 Salgar flash flood: lessons for vulnerable regions in tropical complex terrain", "abstract": "Abstract. Flash floods are a recurrent hazard for many developing Latin American regions due to their complex mountainous terrain and the rainfall characteristics in the tropics. These regions often lack the timely and high-quality information needed to assess, in real time, the threats to the vulnerable communities due to extreme hydrometeorological events. The systematic assessment of past extreme events allows us to improve our prediction capabilities of flash floods. In May 2015, a flash flood in the La Liboriana basin, municipality of Salgar, Colombia, caused more than 100 casualties and significant infrastructure damage. Despite the data scarcity, the climatological aspects, meteorological conditions, and first-order hydrometeorological mechanisms associated with the La Liboriana flash flood, including orographic intensification and the spatial distribution of the rainfall intensity relative to the basin's geomorphological features, are studied using precipitation information obtained using a weather radar quantitative precipitation estimation (QPE) technique, as well as from satellite products, in situ rain gauges from neighboring basins, quantitative precipitation forecasts (QPFs) from an operational Weather Research and Forecasting Model (WRF) application, and data from reanalysis products. The La Liboriana flash flood took place during a period with negative precipitation anomalies over most of the country as a result of an El Nino event. However, during May 2015, moist easterly flow towards the upper part of La Liboriana caused significant orographic rainfall enhancement. The overall evidence shows an important role of successive precipitation events in a relatively short period and of orography in the spatial distribution of rainfall and its intensification as convective cores approached the steepest topography. There were three consecutive events generating significant rainfall within the La Liboriana basin, and no single precipitation event was exceptionally large enough to generate the flash flood, but rather the combined role of precedent rainfall and the extreme hourly precipitation triggered the event. The results point to key lessons for improving local risk reduction strategies in vulnerable regions with complex terrain.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S11069-021-04927-Y", "year": 2021, "title": "River flooding in a changing climate: rainfall-discharge trends, controlling factors, and susceptibility mapping for the Mahi catchment, Western India", "abstract": "The Mahione of the major rivers in Western Indiais subject to frequent major flooding, which severely affects the local economy and infrastructure. Little has been done, however, to assess the flood patterns and severity along its course. Here, the MannKendall and Pettitt tests are used to identify long-term trends of precipitation and peak streamflow at multiple locations in the catchment. Then, flood susceptibility mapping is performed by the analytical hierarchy process, accounting for 14 geomorphic, hydraulic, and geologic factors. The analyses suggest a decline in total precipitation and peak flow discharges at most locations, consistently with the general climatic trend of the area, featuring a weakening summer monsoon. Nonetheless, a significant portion of the catchment area remains highly susceptible to flooding, with stream powers capable of mobilizing boulders up to 1 m in size in extraordinary floods. These results can support the work of engineers and policymakers dealing with floods in the study area, but the proposed methodology can also be applied to other fluvial catchments to evaluate the role of climate trends in modulating flood susceptibility.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/ISPRS-ARCHIVES-XLIII-B3-2020-1263-2020", "year": 2020, "title": "Synergistic use of remote sensing, GIS and hydrological models for study of august 2018 Kerala floods", "abstract": "Abstract. Remote sensing and hydrological models are one of the foremost tools for rapid and comprehensive study of flood hazards and disasters in any parts of the world. Current study is focused on severe 2018 Kerala flood, and is done using various remote sensing data, geospatial tools and combination of hydrological/hydrodynamic/topographical models. Flood mapping is done with pre and post floods remote sensing datasets. For pre-Flood analysis, Normalized Difference Water Index (NDWI) map was prepared on Google Earth Engine (GEE), using Sentinel-2 images for the period of Feb. 2017 to identify permanent water bodies. For post-Flood analysis, GEE was used to download the pre-processed and thermal noise removed Sentinel-1 SAR image for Aug. 9, 2018, Aug. 14 and Aug. 21, 2018 and flood maps were generated using this data. In addition to SAR data, probable flood inundation areas using topography-based flood inundation tool HAND (Height Above Nearest Drainage tool) was also utilized. Hydrological simulation was carried out for all 12 major river sub-basins of Kerala, where floods are reported. Indian Meteorological Department-Global Precipitation Measurement (IMD-GPM) gridded daily data is used as input meteorological data for hydrological simulations. The hydrological simulations results were verified using published Central Water Commission (CWC) reports and reservoirs data for India-WRIS. The hydrodynamic simulation was also performed for simulating the Idukki dam release data and flood condition in downstream areas. Overall, an integrated study and developed approach can be utilized by state and central water and disaster management agencies to develop flood early warning systems.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1038/S41598-022-07720-4", "year": 2022, "title": "Increased flooded area and exposure in the White Volta river basin in Western Africa, identified from multi-source remote sensing data", "abstract": "Accurate information on flood extent and exposure is critical for disaster management in data-scarce, vulnerable regions, such as Sub-Saharan Africa (SSA). However, uncertainties in flood extent affect flood exposure estimates. This study developed a framework to examine the spatiotemporal pattern of floods and to assess flood exposure through utilization of satellite images, ground-based participatory mapping of flood extent, and socio-economic data. Drawing on a case study in the White Volta basin in Western Africa, our results showed that synergetic use of multi-temporal radar and optical satellite data improved flood mapping accuracy (77% overall agreement compared with participatory mapping outputs), in comparison with existing global flood datasets (43% overall agreement for the moderate-resolution imaging spectroradiometer (MODIS) Near Real-Time (NRT) Global Flood Product). Increases in flood extent were observed according to our classified product, as well as two existing global flood products. Similarly, increased flood exposure was also observed, however its estimation remains highly uncertain and sensitive to the input dataset used. Population exposure varied greatly depending on the population dataset used, while the greatest farmland and infrastructure exposure was estimated using a composite flood map derived from three products, with lower exposure estimated from each flood product individually. The study shows that there is considerable scope to develop an accurate flood mapping system in SSA and thereby improve flood exposure assessment and develop mitigation and intervention plans.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1175/JAMC-D-19-0176.1", "year": 2020, "title": "Weather radar network benefit model for flash flood casualty reduction", "abstract": "ABSTRACT A monetized flash flood casualty reduction benefit model is constructed for application to meteorological radar networks. Geospatial regression analyses show that better radar coverage of the causative rainfall improves flash flood warning performance. Enhanced flash flood warning performance is shown to decrease casualty rates. Consequently, these two effects in combination allow a model to be formed that links radar coverage to flash flood casualty rates. When this model is applied to the present-day contiguous U.S. weather radar network, results yield a flash floodbased benefit of $316 million (M) yr1. The remaining benefit pools are more modest ($13 M yr1 for coverage improvement and $69 M yr1 maximum for all areas of radar quantitative precipitation estimation improvements), indicative of the existing weather radar networks effectiveness in supporting the flash flood warning decision process.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1029/2018EF000909", "year": 2018, "title": "Influence of El Ni\u00f1o-Southern Oscillation on Global Coastal Flooding", "abstract": "Anomalous atmosphere-ocean conditions in the tropical Pacific associated with the El Ni\u00f1o-Southern Oscillation (ENSO) drive interannual variations in mean and extreme sea levels. Climate change may lead to more frequent extreme ENSO events in the future. Therefore, it is important to enhance our understanding of ENSO's influence on coastal flood impacts. We assessed ENSO's influence on extreme sea levels using a global reanalysis of tides and storm surges. This allows for a full coverage of the global coastline from 1979 to 2014. A mean sea level component is added to account for steric effects. This results in a substantial improvement in the representation of the seasonal and interannual variability. Our results show significant correlations across the Pacific between ENSO and extreme sea levels (expressed as 95th annual percentiles), which is consistent with previous studies based on tide gauge observations. Average anomalies in the annual percentiles over El Ni\u00f1o years compared to neutral years show similar patterns. When examining total sea levels, results are largely statistically insignificant. This is because in many regions large tidal variability dominates over the other components. Combining sea levels with an inundation and impact model shows that ENSO has a significant but small effect on the number of people potentially exposed to flooding at the globally aggregated scale. Our results demonstrate that a model-based approach allows for an assessment of the influence of ENSO on coastal flood impacts and could be used to assess impacts of future changes in ENSO.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.RSASE.2020.100379", "year": 2020, "title": "Flood susceptibility mapping of the Western Ghat coastal belt using multi-source geospatial data and analytical hierarchy process (AHP)", "abstract": "Progressive environmental and climate change have altogether expanded hydro-meteorological hazards everywhere throughout the world. In recent times, floods have gained increasing global significance as a result of their destructive nature and for causing monetary and human losses. Hitherto, flood mapping studies in India have been profoundly constrained because of the absence of a comprehensive database coordinating flood attributes, for example, peak discharge at river gauges or geospatial data. The present investigation, for the first time, applies a large number of multi-sourced environmental flood conditioning factors (viz. elevation, slope, distance from drainage, drainage density, flow accumulation, topographic wetness index, rainfall, land use, soil texture, topographic ruggedness index and geology) and socio-economic parameters (viz. population density, literacy rate, literate population density, and road density) using the analytical hierarchy process approach to prepare flood susceptibility, vulnerability, and flood risk maps of the entire Western Ghat coastal belt, India. Essential findings of this study demonstrate that a critical percentage of area is involving high (28%) and very high (22%) flood susceptibility. About 25% area shows high flood risk and these regions need immediate attention. Efficiency testing of the flood susceptibility map indicates high precision, utilizing area under the curve (AUC) through a considerably high value (0.84). The output flood risk map can be useful for planners, managers, and regulatory bodies to manage and mitigate flood incidents along the Western Ghat rivers. Even though the methodology applied in this study is highly simple, yet it shows high accuracy, and subsequently, can be utilized in other regions for expert knowledge-based flood mapping.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.BIOCON.2019.01.019", "year": 2019, "title": "Implications of flood disturbance for conservation and management of giant panda habitat in human-modified landscapes", "abstract": "As certain extreme weather events are becoming frequent and intense, conservationists must identify areas across species' ranges recurrently affected, especially with regard to threatened species. Focusing on the giant panda (Ailuropoda melanoleuca) and historical flood frequency distribution, we determined overlaps between panda distribution affected by floods and nature reserves. We also examined the correspondence between areas subject to high flood exposure densities, areas with high panda habitat use, and areas that exhibit high human density. Of the 67 reserves established for giant panda conservation 7 included areas with the highest flood exposure densities while having a mean exposure ranging between 20 and 75%. In Sichuan province up to 32% of areas of high habitat use were subject to low flood density, and 10% overlapped with areas subject to high flood density. We also found that 40% of the total area with high human density was subject to a high flood density. Our findings indicate that high frequency of flooding is affecting areas of nature reserves where people are rather than areas which pandas are using more intensively. In areas occupied by pandas, strategies should remain focus on mitigating habitat degradation and fragmentation caused by human activities that can also reduce habitat resilience to floods. Management aimed at reducing vulnerability and enhancing resilience in flood-prone areas is warranted if we are to prevent negative indirect impacts on panda habitat driven by human responses to increasingly frequent and intense extreme weather events in the coming decades.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/HESS-22-2867-2018", "year": 2018, "title": "Daily GRACE gravity field solutions track major flood events in the GangesBrahmaputra Delta", "abstract": "Abstract. Two daily gravity field solutions based on observations from the Gravity Recovery and Climate Experiment (GRACE) satellite mission are evaluated against daily river runoff data for major flood events in the GangesBrahmaputra Delta (GBD) in 2004 and 2007. The trends over periods of a few days of the daily GRACE data reflect temporal variations in daily river runoff during major flood events. This is especially true for the larger flood in 2007, which featured two distinct periods of critical flood level exceedance in the Brahmaputra River. This first hydrological evaluation of daily GRACE gravity field solutions based on a Kalman filter approach confirms their potential for gravity-based large-scale flood monitoring. This particularly applies to short-lived, high-volume floods, as they occur in the GBD with a 45-year return period. The release of daily GRACE gravity field solutions in near-real time may enable flood monitoring for large events.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1111/JFR3.12598", "year": 2020, "title": "Flood impact on Mainland Southeast Asia between 1985 and 2018\u2014The role of tropical cyclones", "abstract": "Floods are disastrous natural hazards accused of human live losses. As a flood\u2011prone area, Mainland Southeast Asia (MSEA) has often been hit by floods, resulting in the highest fatality in the world. Despite the destructive flood impacts, how has flood occurrence changed over the past decades, and to what extent did floods affect the MSEA are not yet clear. Using the Dartmouth Flood Observatory large flood data archive, we aim to assess the trend of flood occurrence in the MSEA in 1985\u20132018, and quantify the associated impacts on humans. Particularly, the contribution of tropical cyclone (TC) landfall induced floods (TCFloods) is quantified, because of the frequent TC landfalls. Results show that (a) occurrence and maximum magnitude of floods by all causes (ALLFloods) significantly increased (p < .01), but not for TCFloods; (b) On average, TCFloods accounted for 24.6% occurrence of ALLFloods; (c) TCFloods caused higher mortality and displacement rate than ALLFloods did. As low flood protection standards in Cambodia and Myanmar is considered a reason for high flood\u2011induced mortalities, building higher flood protection standards should be taken as a priority for mitigating potential flood impacts. With quantifying flood occurrence and impacts, this study offers scientific understandings for better flood risk management.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/NHESS-18-1493-2018", "year": 2018, "title": "Low cost, multiscale and multi-sensor application for flooded area mapping", "abstract": "Abstract. Flood mapping and estimation of the maximum water depth are essential elements for the first damage evaluation, civil protection intervention planning and detection of areas where remediation is needed. In this work, we present and discuss a methodology for mapping and quantifying flood severity over floodplains. The proposed methodology considers a multiscale and multi-sensor approach using free or low-cost data and sensors. We applied this method to the November 2016 Piedmont (northwestern Italy) flood. We first mapped the flooded areas at the basin scale using free satellite data from low- to medium-high-resolution from both the SAR (Sentinel-1, COSMO-Skymed) and multispectral sensors (MODIS, Sentinel-2). Using very- and ultra-high-resolution images from the low-cost aerial platform and remotely piloted aerial system, we refined the flooded zone and detected the most damaged sector. The presented method considers both urbanised and non-urbanised areas. Nadiral images have several limitations, in particular in urbanised areas, where the use of terrestrial images solved this limitation. Very- and ultra-high-resolution images were processed with structure from motion (SfM) for the realisation of 3-D models. These data, combined with an available digital terrain model, allowed us to obtain maps of the flooded area, maximum high water area and damaged infrastructures.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.RSE.2022.113278", "year": 2022, "title": "Analysis of CYGNSS coherent reflectivity over land for the characterization of pan-tropical inundation dynamics", "abstract": "The monitoring of flood and wetland dynamics at global scale is hampered by several limitations, including a reduced data availability in tropical areas due to the presence of clouds affecting visible and infrared imagery, or low spatial and/or temporal resolutions affecting passive and active microwave Earth Observation (EO) data. As a consequence, surface water extent estimates and their temporal variations remain challenging especially in equatorial river basins. Global Navigation Satellite System Reflectometry (GNSS-R) L-band signals recorded onboard Cyclone GNSS (CYGNSS) mission, composed of 8 Low Elevation Orbit (LEO) satellites, provide information on surface properties at high temporal resolution from 2017 up to now. CYGNSS bistatic observations were analyzed for detecting permanent water and seasonal floodplains over the full coverage of the mission, from 40S to 40N. We computed CYGNSS reflectivity associated to the coherent component of the received power, that was gridded at 0.1 spatial resolution with a 7-day time sampling afterwards. Several statistical metrics were derived from CYGNSS reflectivity, including the weighted mean and standard deviation, the median and the 90th percentile (respectively mean,std,median and 90%) in each pixel. These parameters were clustered using the K-means algorithm with an implementation of the Dynamic Time Warping (DTW) similarity measure. They were compared to static inundation maps, and to dynamic estimations of surface water extent both at the global and regional scales, using the Global Inundation Extent from Multi-Satellites (GIEMS) and MODIS-based products. The difference between 90% and median shows the best sensitivity to the presence of water. The river streams and lakes are correctly detected, and a strong seasonality is identified in CYGNSS reflectivity over the largest floodplains, with the exception of the Cuvette Centrale of Congo which is covered by dense vegetation. This seasonal reflectivity signal correlates well with inundation maps: Pearsons correlation coefficient between median and surface water extent from both GIEMS and MODIS is over 0.8 in the largest floodplains. The spatial patterns of reflectivity are consistent with static inundation maps: at the time of maximum flooding extent, a spatial correlation coefficient around 0.75 with median is obtained for several basins. We also evaluated the dependence of CYGNSS-derived clusters and reflectivity on the dominant land cover type and on the density of Above Groud Biomass (AGB) in the pixel. On the one hand, misclassifications of flooded pixels were observed over vegetated regions, probably due to uncertainties related to the attenuation by the vegetation in both CYGNSS and reference datasets. On the other hand, flooded pixels with a mean AGB up to 300 Mg/ha were correctly detected with the clustering. High reflectivity values are also observed over rocky soils in arid regions and create false alarms. Finally, strong winds on large lakes cause surface roughness, and lower reflectivity values are observed in this case which weaken the detection of open water. While these constraints are to be taken in account and corrected in a future model, a pan-tropical mapping of surface water extent dynamics using CYGNSS can be envisaged.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.ASEJ.2019.12.005", "year": 2020, "title": "Defining the degree of flood hazard using a hydrodynamic approach, a case study: Wind turbines field at west of Suez Gulf", "abstract": "There is a big shortage of drinking water in the western Suez Gulf in Egypt. Fortunately, wind energy is available to cope with the required power for desalination. In previous works the area was subjected to Multi-Criteria Analysis process using a DEM implemented into a GIS environment. For each watershed, a Weighted Standardized Risk Factor (WSRF) was deduced based on the correlation factor for all the main morphological parameters which were obtained from the HEC-HMS model results. Former thought of defining the safe and unsafe watersheds based on global scale and dependent only on (WSRF), is nowadays criticized as a watershed with high value for (WSRF) could have safe specific areas for the wind turbines establishment. A 2D hydrodynamic model was applied on a Macro Scale to deduce inundation maps then were overlaid with wind speeds maps to define the most appropriate locations for wind turbines.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1080/02626667.2021.1998511", "year": 2021, "title": "Recent hydrological evolutions of the Senegal River flood (West Africa)", "abstract": "The flood of the Senegal River is a resource for the populations of the Senegal valley, who practise agriculture, fishing and livestock farming in the annually flooded areas. The objective of this paper is to investigate the hydrological evolution of the Senegal River flood since the drought of the 1970s and the construction and management of the Manantali Dam. To this purpose, the paper analyses the evolution of several parameters of the flood hydrograph and defines the factors that determine the intensity of the flood. Also, a follow-up of the flooded areas in the valley is carried out using remote sensing. The results show that the flood hydrograph has been similar since the 1970s drought, due to the reduction in contributions from the Bafing after the construction of the Manantali Dam. As a result, the high floods depend now on the rainfall pattern in the Sudano-Sahelian zone of the watershed.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/2017EF000671", "year": 2018, "title": "Long-Term Changes in Global Socioeconomic Benefits of Flood Defenses and Residual Risk Based on CMIP5 Climate Models", "abstract": "A warmer climate is expected to accelerate the global hydrological cycle, causing more intense precipitation and floods. Despite recent progress in global flood risk assessment, the socioeconomic benefits of flood defenses (i.e., reduction in population/economic exposure) and the residual risk (i.e., residual population/economic exposure) are poorly understood globally and regionally. To address these knowledge gaps, we use the runoff data from a baseline and 11 Coupled Model Intercomparison Project Phase 5 (CMIP5) climate models to drive the Catchment-based Macro-scale Floodplain model incorporating the latest satellite river width information. From the simulated annual maxima, we use a Gumbel distribution to estimate the river water depth-flood return period relationship. We independently evaluate flood impacts on population and economy (i.e., gross domestic product) for a range of flood return periods. We estimate the socioeconomic benefits and the corresponding residual risk for the globe and 26 subcontinental regions. The global population (gross domestic product) exposed to flooding is \u223c8% (\u223c7%) per year lower when implementing existing flood protection infrastructure extracted from the FLOod PROtection Standards database. If the current flood defenses were to be unchanged in the future (Representative Concentration Pathway 4.5 [RCP4.5] and RCP8.5, i.e., \u223c2 to \u223c4.3\u00b0C above the preindustrial levels), the globe and most of the regions (particularly where developing countries are concentrated) would experience an increase in residual risk. This increase is especially obvious when the gap of climate forcing between RCP8.5 and RCP4.5 widens by the end of the 21st century. We finally evaluate the impact of changed flood defense levels on the socioeconomic benefits and the corresponding residual risk.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/HESS-25-2843-2021", "year": 2021, "title": "Urban surface water flood modelling\u2013a comprehensive review of current models and future challenges", "abstract": "Abstract. Urbanisation is an irreversible trend as a result of social and economic development. Urban areas, with high concentration of population, key infrastructure, and businesses, are extremely vulnerable to flooding and may suffer severe socio-economic losses due to climate change. Urban flood modelling tools are in demand to predict surface water inundation caused by intense rainfall and to manage associated flood risks in urban areas. These tools have been rapidly developing in recent decades. In this study, we present a comprehensive review of the advanced urban flood models and emerging approaches for predicting urban surface water flooding driven by intense rainfall. The study explores the advantages and limitations of existing model types, highlights the most recent advances, and identifies major challenges. Issues of model complexities, scale effects, and computational efficiency are also analysed. The results will inform scientists, engineers, and decision-makers of the latest developments and guide the model selection based on desired objectives.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S11069-014-1496-6", "year": 2015, "title": "The failed-levee effect: Do societies learn from flood disasters?", "abstract": "Human societies have learnt to cope with flood risks in several ways, the most prominent ways being engineering solutions and adaptive measures. However, from a more sustainable point of view, it can be argued that societies should avoid or at least minimize urban developments in floodplain areas. While many scientists have studied the impact of human activities on flood risk, only a few studies have investigated the opposite relationships, i.e. the impacts of past flood events on floodplain development. In this study, we make an initial attempt to understand the impact of the occurrence of flood disasters on the spatial distribution of population dynamics in floodplain areas. Two different methodologies are used to uncover this relationship, a large-scale study for the USA and a case-study analysis of the 1993 Mississippi flood. The large-scale analysis is performed at county level scale for the whole of the USA and indicates a positive relationship between property damage due to flood events and population growth. The case-study analysis examines a reach of the Mississippi river and the territory, which was affected by flooding in 1993. Contrary to the large-scale analysis, no significant relationship is found in this detailed study. However, a trend of dampened population growth right after the flood followed by an accelerated growth a decade later could be identified in the raw data and linked to explanations found in the literature.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1080/15481603.2019.1627062", "year": 2019, "title": "Landsat-MODIS image fusion and object-based image analysis for observing flood inundation in a heterogeneous vegetated scene", "abstract": "Typhoon flooding normally occurs suddenly with short duration, and the thick cloud cover limits the ability of one single satellite to timely capture the inundation extent. Landsat satellite data with a spatial resolution of 30 m is spatially applicable for flooding research; however, its 16-day observation frequency is typically insufficient to observe short-term typhoon inundation. Alternatively, despite the coarse spatial resolutions, the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor provide daily data, which is well suited for flood-related investigations. Accordingly, the idea of combining these two sources of data to generate a high spatial and temporal image would be useful. In this study, the Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model (ESTARFM) was applied to generate cloud-free Landsat/MODIS synthesized data with a spatial resolution of 30 m for the delineation of the inundated areas during a flood event. This approach produces a Landsat-scale image for fine-scale flood mapping of areas where there are no observed cloud-free Landsat or similar resolution satellite images. The fusion model was implemented on atmospherically corrected surface reflectance, and the resultant reflectance values were validated by comparing with observed Landsat reflectance before further data interpretation. The blending results indicate that the synthetic Landsat-scaled image is highly correlated with Landsat surface reflectance, captured a day after the synthetic image acquisition date, over cloud-free areas. For image interpretation, an object-based image analysis (OBIA) approach with an optimal-scale segmentation and the support vector machine (SVM) classifier was applied for flood classification. The flood mapping result was validated by comparing with a reference flood map derived from an observed Landsat image. This study demonstrates that the techniques of image fusion and object-based image analysis are useful for observing flood inundation in the heterogeneous vegetated area.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.3390/RS13234761", "year": 2021, "title": "Flood Hazard Mapping Using Fuzzy Logic, Analytical Hierarchy Process, and Multi-Source Geospatial Datasets", "abstract": "Iran is among the driest countries in the world, where many natural hazards, such as floods, frequently occur. This study introduces a straightforward flood hazard assessment approach using remote sensing datasets and Geographic Information Systems (GIS) environment in an area located in the western part of Iran. Multiple GIS and remote sensing datasets, including Digital Elevation Model (DEM), slope, rainfall, distance from the main rivers, Topographic Wetness Index (TWI), Land Use/Land Cover (LULC) maps, soil type map, Normalized Difference Vegetation Index (NDVI), and erosion rate were initially produced. Then, all datasets were converted into fuzzy values using a linear fuzzy membership function. Subsequently, the Analytical Hierarchy Process (AHP) technique was applied to determine the weight of each dataset, and the relevant weight values were then multiplied to fuzzy values. Finally, all the processed parameters were integrated using a fuzzy analysis to produce the flood hazard map with five classes of susceptible zones. The bi-temporal Sentinel-1 Synthetic Aperture Radar (SAR) images, acquired before and on the day of the flood event, were used to evaluate the accuracy of the produced flood hazard map. The results indicated that 95.16% of the actual flooded areas were classified as very high and high flood hazard classes, demonstrating the high potential of this approach for flood hazard mapping.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.03.212", "year": 2019, "title": "Evaluating natural infrastructure for flood management within the watersheds of selected global cities", "abstract": "Cities are dependent on their upstream watersheds for storage and gradual release of water into river systems. These watersheds act as important flood mitigation infrastructure, providing an essential ecosystem service. In this paper we use metrics from the WaterWorld model to examine the flood management-relevant natural infrastructure of the upstream watersheds of selected global cities. These metrics enable the characterisation of different types, magnitudes and geographical distributions of potential natural flood storage. The storages are categorised as either green (forest canopy, wetland and soil) or blue (water body and floodplain) storages and the proportion of green to blue indicates how different city upstream basin contexts provide different types and levels of storage which may buffer flood risk. We apply the WaterWorld method for examining flood risk as the ratio of accumulated modelled annual runoff volume to accumulated available green and blue water storage capacity. The aim of these metrics is to highlight areas where there is more runoff than storage capacity and thus where the maintenance or restoration of further natural infrastructure (such as canopy cover, wetlands and soil) could aid in storing more water and thus better alleviate flood risks. Such information is needed by urban planners, city authorities and governments to help prepare cities for climate change impacts.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1038/S41598-019-56409-8", "year": 2019, "title": "Linking flow-stream variability to grain size distribution of suspended sediment from a satellite-based analysis of the Tiber River plume (Tyrrhenian Sea)", "abstract": "Several coastal regions on Earth have been increasingly affected by intense, often catastrophic, flash floods that deliver significant amounts of sediment along shorelines. One of the critical questions related to the impact of these impulsive runoffs is are flash floods more efficient in delivering non-cohesive sandy sediment along the coasts? Here we relate flow stages (i.e., from erratic to persistent) to the grain size distribution of the suspended load, by performing a synergic analysis of in-situ river discharge and satellite-retrieved grain size distribution, from 2002 to 2014, covering the 2012 Tiber River (Italy) exceptional flood event. Our analysis shows novel and promising results regarding the capability of remote sensing in characterizing suspended sediment in terms of grain size distribution and reveals that erratic stages favour delivering of non-cohesive sandy sediment more than the persistent stages. This conclusion is supported by numerical simulations and is consistent with previous studies on suspended sediment rating curves.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S40808-020-00937-0", "year": 2021, "title": "Quantification of flood mitigation services by urban green spaces using InVEST model: a case study of Hyderabad city, India", "abstract": "Urban floods have become more frequent across the globe. The transformation of the urban landscape with increased concretization and dwindling green cover has resulted in excess run-off generation thereby causing the flash floods. The protective role and ecosystem benefits of urban green spaces needs to be quantified so that it will unlock the possibilities of integrating natural capital thinking into policymaking. Hence in this study, we quantified the flood mitigation service of green spaces and estimated the tangible economic damage to the built infrastructure in the Hyderabad metropolitan city, India using the Integrated Valuation of Ecosystem Services and Trade-offs model. The analysis was carried out for 2-years and 5-years design precipitation of 1 h duration. Results show that 4450% of the precipitation is retained by the urban green and open spaces. With an increase of 13% in the rainfall intensity (from 2-years to 5-years), the run-off volume has increased by 21%, while the run-off retained has increased only by 5%, which indicates that even slight increase in rainfall intensity results in huge run-off generation that causes commensurate economic damages. The economic damage due to flood inundation of the built infrastructure is estimated to be 1.39 million USD using the unit cost method. Overall, the indicator of run-off retention service is quantified as 4.25E + 13 and 4.46E + 13 for the 2-years and 5-years return period precipitation, respectively. The structural and non-structural flood mitigation measures are also enumerated along with the limitations of the model.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/978-981-15-9805-0_15", "year": 2021, "title": "Flood Hazard Mapping and Vulnerability Analysis Along Seti River in Pokhara Metropolitan City", "abstract": "Flood is frequent during every monsoon in Nepal which poses threat to life and property in lowland areas. Among 6000 rivers and rivulets, most are prone to floods in Nepal. Seti River flows from Machhapuchhre Rural Municipality in the north, along the center of Pokhara Metropolitan City, and toward Tanahu which meets with Madi River there. Seti flood of 2012 was one of the devastating floods which took the life of many people and destroyed infrastructures along its way. So, Pokhara Metropolitan City lies at a high risk of flood impacts. Hydrodynamic simulation using HEC-RAS and GIS is one of the important methods of estimating the probable loss due to flood of various scenarios quantitatively. In this study, flood hazard maps of Seti River across Pokhara Metropolitan City has been prepared for different flood scenarios. The flood frequency analysis was performed using Gumbel, Log-Pearson, Log Normal, and Fullers Method. The goodness of fit was performed using chi square test, and results of Gumbel method was used as it was found more appropriate than other methods for this basin. One-dimensional steady hydrodynamic modeling was done to create water surface profile which was used to prepare hazard maps and vulnerability maps for various return periods. The model was evaluated using statistical parameters, coefficient of determination R2), and NashSutcliffe efficiency (NSE) whose values were found to be 0.951 and 0.819, respectively. The maps prepared can be used for planning the built-up areas along the river sides and may help in decision making for flood mitigation measures.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/HYP.11459", "year": 2018, "title": "Intercomparison of snow water equivalent observations in the Northern Great Plains", "abstract": "AbstractIn the Northern Great Plains, melting snow is a primary driver of spring flooding, but limited knowledge of the magnitude and spatial distribution of snow water equivalent (SWE) hampers flood forecasting. Passive microwave remote sensing has the potential to enhance operational river flow forecasting but is not routinely incorporated in operational flood forecasting. We compare satellite passive microwave estimates from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSRE) to the National Oceanic and Atmospheric Administration Office of Water Prediction (OWP) airborne gamma radiation snow survey and U.S. Army Corps of Engineers (USACE) ground snow survey SWE estimates in the Northern Great Plains from 2002 to 2011. AMSRE SWE estimates compare favourably with USACE SWE measurements in the low relief, low vegetation study area (mean difference = 3.8 mm, root mean squared difference [RMSD] = 34.7 mm), but less so with OWP airborne gamma SWE estimates (mean difference = 9.5 mm, RMSD = 42.7 mm). An error simulation suggests that up to half of the error in the former comparison is potentially due to subpixel scale SWE variability, limiting the maximum achievable RMSD between ground and satellite SWE to approximately 2633 mm in the Northern Great Plains. The OWP gamma versus AMSRE SWE comparison yields larger error than the pointscale USACE versus AMSRE comparison, despite a larger measurement footprint (57 km2 vs. a few square centimetres, respectively), suggesting that there are unshared errors between the USACE and OWP gamma SWE data.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2021GL095441", "year": 2021, "title": "A Dusty Atmospheric River Brings Floods to the Middle East", "abstract": "Torrential rainfall and rapid snowmelt in April 2017 caused deadly floods in northwestern Iran. An atmospheric river (AR), propagating across the Middle East and North Africa, was found responsible for this extreme event. The snowmelt was triggered by precipitation and warm advection associated with the AR. Total satellite-based rainfall for April 2017 was moderately below normal, suggesting that a heavy flood can happen during dry years. The AR was fed by moisture from the Mediterranean and Red Seas. Despite its adverse societal consequences, this event was beneficial to the recovery of the desiccating Lake Urmia. The impacts of this AR were not limited to flooding; it also facilitated dust transport to the region. This distinct characteristic of the ARs in the Middle East is attributed to major mineral dust sources located along their pathways. This event was reasonably predicted at 7-day lead time, crucially important for successful early warning systems.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1029/2019GL085134", "year": 2019, "title": "A CYGNSSBased Algorithm for the Detection of Inland Waterbodies", "abstract": "The Cyclone Global Navigation Satellite System (CYGNSS) is a new constellation of eight low Earth orbiting spacecrafts that receive both direct and reflected signals from GPS satellites. Coherent reflection of the GPS signal from standing water over land results in a high surface reflectivity signal in the CYGNSS data. An image processing algorithm is presented, which leverages the surface reflectivity signal to produce a watermask of inland waterbodies at 0.01\u00b0 \u00d7 0.01\u00b0 spatial resolution. The watermask is compared to hand-drawn maps of inland waterbodies, as well as to the MODIS watermask product. We find that the CYGNSS watermask provides accurate, time-varying maps that are able to resolve changes in lake and river position and extent. With CYGNSS' short return time, watermasks can be generated using as little as half a month of data to produce near-real-time maps of flooding events.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S42452-021-04460-4", "year": 2021, "title": "Climate-induced flood inundation for the Arial Khan River of Bangladesh using open-source SWAT and HEC-RAS model for RCP8. 5-SSP5 scenario", "abstract": "Bangladesh is one of the largest flood-prone deltas of the GBM (GangesBrahmaputraMeghna) basins, and recently, it is categorized as the 7th worst climate-affected country in the world. Future climate change along with economic development, urbanization, and increase in population may worsen this situation manifolds. To cope with future flood situations and lessen probable flood losses, it is essential to develop flood maps of the major flood-prone rivers of Bangladesh considering climate change scenarios. In this study, the flood inundation of the Arial Khan River and its floodplain has been assessed for the predicted climate change scenario of RCP 8.5 (Representative Concentration Pathway 8.5) using open-source mathematical models. A calibrated and validated hydrologic model of GBM basins in SWAT (Soil and Water Assessment Tool) model has been used to estimate the future flow magnitudes at Bahadurabad Transit (Brahmaputra River) and Hardinge Bridge (Ganges River) using extreme emission scenario RCP 8.5. Using the flow magnitude of these two stations as the upstream boundaries, an HEC-RAS 1D model has been set up for the Brahmaputra, Ganges, and Padma rivers for generating future flow magnitude at the offtake of the Arial Khan River. Later, an HEC-RAS 1D-2D coupled model is set up for the Arial Khan River floodplain and flood maps are prepared considering flood depth, duration, and inundation extent. The flood assessment for different projections of RCP 8.5 shows that there is an increasing trend of flood in terms of depth, duration, and inundation from the 2020s to the 2080s. Hence, the floodplain becomes more hazardous by the end of this century. The climate change impact on the projected population for the RCP 8.5 scenario is assessed under SSP5 (Shared Socioeconomic Pathways 5) which indicates that the total flood-affected population will be nearly twice in the 2080s compared to the 2020s. So, future climate change is going to have a dreadful effect on the flood situation of the Arial Khan River floodplain.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1038/S41467-020-16171-2", "year": 2020, "title": "Social-media and newspaper reports reveal large-scale meteorological drivers of floods on Sumatra", "abstract": "Floods are a major contributor to natural disasters in Sumatra. However, atmospheric conditions leading to floods are not well understood due, among other factors, to the lack of a complete record of floods. Here, the 5 year flood record for Sumatra derived from governmental reports, as well as from crowd-sourcing data, based on Twitter messages and local newspapers reports, is created and used to analyze atmospheric phenomena responsible for floods. It is shown, that for the majority of analyzed floods, convectively coupled Kelvin waves, large scale precipitation systems propagating at 12 m/s along the equator, play the critical role. While seasonal and intraseasonal variability can also create conditions favorable for flooding, the enhanced precipitation related to Kelvin waves was found in over 90% of flood events. In 30% of these events precipitation anomalies were attributed to Kelvin waves only. These results indicate the potential for increased predictability of flood risk.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.3390/RS14153647", "year": 2022, "title": "Detection of Flash Flood Inundated Areas Using Relative Difference in NDVI from Sentinel-2 Images: A Case Study of the August 2020 Event in Charikar, Afghanistan", "abstract": "On 26 August 2020, a devastating flash flood struck Charikar city, Parwan province, Afghanistan, causing building damage and killing hundreds of people. Rapid identification and frequent mapping of the flood-affected area are essential for post-disaster support and rapid response. In this study, we used Google Earth Engine to evaluate the performance of automatic detection of flood-inundated areas by using the spectral index technique based on the relative difference in the Normalized Difference Vegetation Index (rdNDVI) between pre- and post-event Sentinel-2 images. We found that rdNDVI was effective in detecting the land cover change from a flash flood event in a semi-arid region in Afghanistan and in providing a reasonable inundation map. The result of the rdNDVI-based flood detection was compared and assessed by visual interpretation of changes in the satellite images. The overall accuracy obtained from the confusion matrix was 88%, and the kappa coefficient was 0.75, indicating that the methodology is recommendable for rapid assessment and mapping of future flash flood events. We also evaluated the NDVIs changes over the course of two years after the event to monitor the recovery process of the affected area. Finally, we performed a digital elevation model-based flow simulation to discuss the applicability of the simulation in identifying hazardous areas for future flood events.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/978-981-15-2006-8_1", "year": 2020, "title": "Overview of the Mekong River Basin", "abstract": "The Lancang-Mekong River, the largest transboundary river in Southeast Asia, flows through six riparian countries, nurtures splendid culture along it. The river is called Lancang River in China, and Mekong River out of China. The Mekong River region is featured by various landscape patterns and high variability of rainfall caused by monsoon cycles. This region is also featured by high density of population, high potential of development and high international attention, which make this study more meaningful. The physical geographical feature of this region is illustrated from the aspects of topography, meteorology and hydrology in this chapter. The Socio-economy characteristics of this region is also reviewed in this chapter to provide background knowledge for the further analysis of flood and drought management. The irrigation projects and hydropower projects, main types of structural measures, are also briefly introduced from the whole basin view.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.JPUBECO.2022.104604", "year": 2022, "title": "Home bias in humanitarian aid: The role of regional favoritism in the allocation of international disaster relief", "abstract": "This paper investigates whether regional favoritism shapes humanitarian aid flows. Using a rich and unique dataset derived from reports of the Office of US Foreign Disaster Assistance (OFDA), we show that substantially larger amounts of aid are disbursed when exogenous natural disasters hit the birth region of the recipient countries political leader. While we find no evidence that US commercial or political interests affect the size of this home bias, the bias is stronger in countries with a weaker bureaucracy and governance, suggesting the absence of effective safeguards in the allocation of aid.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.GEOMORPH.2016.03.022", "year": 2016, "title": "The flood of 2011 in the lower Chao Phraya valley, Thailand: Study of a long-duration flood through satellite images", "abstract": "The paper illustrates application of satellite images for studying the anatomy of a long-duration, extensive, and slow flood on the Chao Phraya River in 2011 that inundated Bangkok in its lower reach. The spread of floods in the valley was mapped with MODIS, month by month, from July 2011 to February 2012. A subsampled WorldView-2 mosaic was used to observe part of the valley in detail. The flood in Bangkok was studied with four higher-resolution images from Spot 4, WorldView-2, and GeoEye-1 satellites. We suspect that the floodwaters jumped the banks of the Chao Phraya south of Chai Nat, and then travelled overland and along river channels. The overland passage made it difficult to protect settlements. We also studied sedimentation from the images of this shallow overland flow across the country, which was complicated by the presence of preexisting embankments, other anthropogenic structures, and smaller stream channels. This is a descriptive study but it highlights the nature of flooding that is likely to be repeated in this low flat valley from high rainfall. The pattern of flooding was similar to that of a previous large flood in 1996 recorded in a SPOT 2 image. These floods impact Bangkok periodically, a city of about 10 million people, which started on a levee in a low flat delta, then expanded into backswamps, and is marked with local depressions from groundwater extraction. These slow extensive floods can be mapped from satellite images and properly recorded as an early step in analysis of large floods. Mapping of such floods on ground is logistically impossible. Slow, extensive, and long-lasting floods affect lower valleys and deltas of a number of major rivers, impacting agricultural fields and large populations. These floods are especially disastrous for cities located on low deltas. We submit that basic exercises on satellite images provide valuable introductory information for understanding geomorphology of such floods, and also for structuring plans for flood amelioration. Satellite images at very high resolutions, also used in this study, provide complimentary data to mapping and ground observation. Basin environments that are inundated by large shallow extensive floods are not unusual. In future, climate change is expected to raise the frequency of floods in lower parts of a number of river valleys and deltas, so that for such an environment slow extensive floods may become common and need to be studied. In that sense this is a template for studying large slow floods, arguably more frequent in future.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/2013WR014091", "year": 2014, "title": "Flooding dynamics on the lower Amazon floodplain: 1. Hydraulic controls", "abstract": "Modeling the routing of flood waters across large floodplains is challenging because flows respond to dynamic hydraulic controls from complex geomorphology, vegetation, and multiple water sources. In this study, we analyzed the topographic and hydrologic controls of inundation dynamics of a large floodplain unit (2440 km2) along the lower Amazon River. We combined land topography derived from the Shuttle Radar Topography Mission (SRTM) with underwater topography derived from an extensive echo-sounding survey to generate a seamless digital elevation model (DEM). Floodplain inundation was simulated using LISFLOOD-FP, which combines one-dimensional river routing with two-dimensional overland flow, and a local hydrological model. For the first time, accurate simulation of filling and drainage of an Amazon floodplain was achieved with quantification of changes in water elevation, flooding extent, and river-floodplain exchange. We examined the role of diffuse overbank versus channelized flows on river-floodplain exchange. Diffuse overbank flows represent 93% of total river to floodplain discharge and 54% of floodplain to river discharge. Floodplain discharge during high-water was four times higher than field observation values when the SRTM v.4 DEM with no correction was used for simulation because of a -4.4 m elevation bias originating from residual motion errors of the SRTM interferometric baseline.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1073/PNAS.2018293118", "year": 2021, "title": "Humanitarian need drives multilateral disaster aid", "abstract": "Significance\r\n Threats to human livelihoods resulting from natural hazards are increasing due to climate change. Climate-related disasters such as floods, storms, and droughts have destroyed shelter, reduced crop yields, harmed livestock, and fueled conflict, especially in developing countries. The key finding is that UN aid in the aftermath of climate-related disasters is largely driven by humanitarian need. The UN seems able to fend off donor states strategic interest and allocate more aid after disasters where hazard severity is greater and need is more pressing. Based on this finding, we argue that the UN lives up to its stated principles of neutrality, impartiality, and independence in disaster aid, corroborating the legitimacy of the UN in allocating disaster aid.\r\n , \r\n As the climate changes, human livelihoods will increasingly be threatened by extreme weather events. To provide adequate disaster relief, states extensively rely on multilateral institutions, in particular the United Nations (UN). However, the determinants of this multilateral disaster aid channeled through the UN are poorly understood. To fill this gap, we examine the determinants of UN disaster aid using a dataset on UN aid covering almost 2,000 climate-related disasters occurring between 2006 and 2017. We make two principal contributions. First, we add to research on disaster impacts by linking existing disaster data from the Emergency Events Database (EM-DAT) to a meteorological reanalysis. We generate a uniquely global hazard severity measure that is comparable across different climate-related disaster types, and assess and bolster measurement validity of EM-DAT climate-related disasters. Second, by combining these data with social data on aid and its correlates, we contribute to the literature on aid disbursements. We show that UN disaster aid is primarily shaped by humanitarian considerations, rather than by strategic donor interests. These results are supported by a series of regression and out-of-sample prediction analyses and appear consistent with the view that multilateral institutions are able to shield aid allocation decisions from particular state interests to ensure that aid is motivated by need.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3897/ONEECO.7.E87458", "year": 2022, "title": "Urban ecosystems and heavy rainfall \u2013 A Flood Regulating Ecosystem Service modelling approach for extreme events on the local scale", "abstract": "Increasing urbanisation in combination with a rise in the frequency and intensity of heavy rain events increase the risk of urban flooding. Flood Regulating Ecosystem Services (FRES) address the capacity of ecosystems to reduce the flood hazard and lower damage. FRES can be estimated by quantification of supply (provision of a service by an ecosystem) and demand (need for specific ES by society). However, FRES for pluvial floods in cities have rarely been studied and there is a gap in research and methods on FRES supply and demand quantification.\r\n In this study, we assessed FRES of an urban district in the City of Rostock (Germany) for a one-hour heavy rainfall event using the hydrological model LEAFlood. The hydrological model delivered the FRES supply indicators of soil water retention and water retained by canopies (interception). An intersection of the potential demand (based on indicators of population density, land reference value, monuments and infrastructure) and the modelled surface water depth revealed the actual demand. Comparing the actual demand and supply indicated the budget of FRES to identify unmet demand and supply surplus.\r\n Results show highest mean FRES supply on greened areas of forests, woodlands and green areas, resulting in a supply surplus. Whereas, sealed areas (paved surface where water cannot infiltrate into the soil), such as settlements, urban dense areas, traffic areas and industry, have an unmet demand resulting from low supply and relatively high actual demand.\r\n With the hydrological model LEAFlood, single landscape elements on the urban scale can be evaluated regarding their FRES and interception can be considered. Both are important for FRES assessment in urban areas. In contrast to flood risk maps, the study of FRES gives the opportunity to take into account the contribution of nature to flood regulation benefits for the socio-economic system. The visualisation of FRES supply and demand balance helps urban planners to identify hotspots and reduce potential impacts of urban pluvial flooding with ecosystem-based adaptations.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.SCITOTENV.2020.138287", "year": 2020, "title": "Putting the poorly documented 1998 GLOF disaster in Shakhimardan River valley (Alay Range, Kyrgyzstan/Uzbekistan) into perspective", "abstract": "On July 8, 1998, the deadliest glacier lake outburst flood (GLOF) in Central Asia for at least the last 100 years occurred in the Shakhimardan catchment, Kyrgyzstan. Most of the >100 victims were, however, killed in the Uzbek enclave of Shakhimardan, i.e. in the downstream part of this transboundary catchment. No warnings were issued between the two countries. In addition, due to political tensions, access to the site was impossible and a detailed assessment of the disaster could not be realized until now. Using remote sensing, we show that the lake at the origin of the Shakhimardan event appeared in the 1960s and drained periodically, without, however, causing damage to downstream areas before it eventually disappeared in the late 1980s. Based on post-event videos, we conclude that the GLOF-producing depression was again filled with a lake, estimated at 20 1.2 103 m2 in area, before the disaster. The lake burst was likely driven by the rapidly rising air temperatures and the melting of snow/ice in late June and early July. The GLOF first travelled as a debris flow for 17 km, then continued as a debris flood in the increasingly flatter channel for another 20 km. Interestingly, the mean weighted channel angle in the areas of erosion was extremely low at 6.7. The flood continued further downstream for ~100 km from its source. Today, 32 lakes (total area ~300 103 m2 in 2018) exist in the catchment, with several of the larger lakes (>5 103 m2) showing signs of instability. We therefore call for a systematic monitoring of environments like the Shakhimardan catchment, as well as for the installation of early warning systems at critical sites, with exchange of data between the Kyrgyz and Uzbek disaster risk management units, so as to mitigate existing and evolving GLOF risks.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.GLOENVCHA.2022.102468", "year": 2022, "title": "The importance of infrastructure and national demand to represent", "abstract": "A new US hydroeconomic model quantifies water stress accounting for infrastructure. A third of US counties are unable to meet their water demands from renewable sources. Water stress is greatly overestimated by metrics based only on local runoff. Reservoirs reduce both total water supply failure and its intra-annual variability. Over 40% of counties overcome deficits during dry months due to existing reservoirs.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.EJRH.2015.11.004", "year": 2016, "title": "Extreme flood events in the Bolivian Amazon wetlands", "abstract": "Study region\nThe Amazonian wetlands of Bolivia, known as the Llanos de Moxos, are believed to play a crucial role in regulating the upper Madeira hydrological cycle, the most important southern tributary of the Amazon River. Because the area is vast and sparsely populated, the hydrological functioning of the wetlands is poorly known.\nStudy focus\nWe analyzed the hydrometeorological configurations that led to the major floods of 2007, 2008 and 2014. These data, together with flood mapping derived from remote sensing images, were used to understand the dynamics of the Llanos during the three flood events.\nNew hydrological insights for the region\nThe results showed that large floods are the result of the superimposition of flood waves from major sub-basins of the region. As a previous study suggested, the dynamics of the floods are controlled by an exogenous process, created by the flood wave originating in the Andes piedmont that travels through the Mamore River; and by an endogenous process, which is the runoff originating in the Llanos. Our study showed that the first process is evident only at the initial phase of the floods, and although important for attenuating the rising flood wave, it is of lesser importance compared to the endogenous process. We conclude that the endogenous process controls the magnitude and duration of major floods.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1109/JSTARS.2019.2926058", "year": 2019, "title": "Comparison of satellite passive microwave with modeled snow water equivalent estimates in the Red River of the North Basin", "abstract": "The Red River of the North basin (RRB) is vulnerable to spring snowmelt flooding because of its flat terrain, low permeability soils, and the presence of river ice jams resulting from the river's northward flow direction. The onset and magnitude of major flood events in the RRB have been very difficult to forecast, in part due to limited field observations of snow water equivalent (SWE). Coarse-resolution (25-km) passive microwave observations from satellite instruments are well suited for the monitoring of SWE. Despite routine use in the Earth sciences community to document the impacts of climate change, the use of passive microwave observations in operational flood forecasting is rare. This paper compares daily satellite passive microwave SWE observations from special sensor microwave/imager (SSM/I) and special sensor microwave imager/sounder (SSMIS), advanced microwave scanning radiometer for earth observing system (AMSR-E), and advanced microwave scanning radiometer 2 (AMSR2) from 2003 to 2016 to modeled output from the SNOw Data Assimilation System (SNODAS) and Global Snow Monitoring for Climate Research-2 (GlobSnow-2) in the RRB to determine the differences between the remotely sensed SWE estimates and the model products currently used in flood forecasting. Results show statistically significant differences between the satellite observations and SNODAS in the northern region of the basin that were not evident in the southern region. Satellite estimates of peak SWE in the forecast subbasins in the northern region were 40-125% higher than the model results which points to the lack of ground observations used to constrain the model simulations. This paper recommends that satellite SWE observations should be considered for improving operational snowmelt forecasting in the RRB.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.RSE.2018.04.016", "year": 2018, "title": "Addressing spatio-temporal resolution constraints in Landsat and MODIS-based mapping of large-scale floodplain inundation dynamics", "abstract": "Recent studies have developed novel long-term records of surface water (SW) maps on continental and global scales but due to the spatial and temporal resolution constraints of available satellite sensors, they are either of high spatial and low temporal resolution or vice versa. In this study, we address this limitation by exploring two approaches for generating an 8-day series of Landsat resolution (30 m) SW maps for three floodplain sites in south-eastern Australia during the 2010 La Nina Floods. Firstly, we applied a generalized additive regression model (GAM) that empirically relates Landsat-based SW extent to in-situ river flow to then predict additional time steps. Secondly, we used the STARFM and ESTARFM blending algorithms for predicting the Open Water Likelihood at 8-daily intervals and 30 m resolution from Landsat and MODIS imagery. ESTARFM outperformed STARFM and best blending accuracies were achieved in the floodplain site with the slowest changes in inundation extent through time. There was good agreement between the blended and statistically-modeled 8-day SW series and both series provided new and temporally consistent information about changes in inundation extent throughout the flooding cycles. After careful consideration of accuracy limitations and model assumptions, these SW records hold great potential for assimilation into hydrodynamic and hydrological models as well as improved management of terrestrial freshwater ecosystems.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.GLOPLACHA.2020.103125", "year": 2020, "title": "Identifying global hotspots where coastal wetland conservation can contribute to nature-based mitigation of coastal flood risks", "abstract": "Low-lying coastal zones are increasingly exposed to flood risks due to global change including sea level rise, increasing storm intensity and growing coastal population densities. Local to regional-scale studies have demonstrated that conservation or restoration of coastal wetland ecosystems, such as salt marshes and mangroves, provides nature-based risk mitigation, as these wetlands have the natural capacity to mitigate the impacts of storm surges and related flood risks. Yet, it is unknown how important this nature-based mitigation of coastal flood risks is on a global scale. Here we present the results of a global-scale GIS model assessing the global distribution of inland surface areas and population numbers exposed to storm surges that would first propagate through tidal wetlands before they reach the inhabited land, and hence that would receive storm surge mitigation by the mangrove forests and salt marshes. Further our model quantifies the distance travelled by a storm surge through the tidal wetlands as a measure of the magnitude of storm surge mitigation. Results show that on a worldwide scale, about 30% of the flood-exposed low-lying coastal plain benefits from nature-based storm surge mitigation by tidal wetlands, with the largest areas located in deltas (e.g. Pearl River, Yangtze, Mekong) and estuaries (e.g. Elbe). Areas protected by large wetlands, where a storm surge would first propagate through >5 km of tidal wetlands before it reaches vulnerable land and people, are located in river deltas such as of the Guayas (Ecuador), Mississippi (USA) and Ganges-Brahmaputra (India and Bangladesh). About 35% of the global flood-exposed coastal population receives nature-based storm surge mitigation. The majority of that population (80%) is located in five countries, i.e. China, Vietnam, the Netherlands, India and Germany. Areas more exposed to extreme storm surges (Eastern America, Caribbean Sea, Eastern Asia) include hotspot areas where storm surges are travelling through wider tidal wetlands generating higher risk mitigation, as for example in the Mississippi delta, Chesapeake bay, Ganges-Brahmaputra delta or Yangtze delta. Our global assessment aims to increase general awareness on the capacity of nature-based coastal flood risk mitigation, and to stimulate further local scale analyses in support of its wider application around the world.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.JENVMAN.2022.115492", "year": 2022, "title": "Application of Unmanned Aerial Vehicle DEM in flood modeling and comparison with global DEMs: Case study of Atrak River Basin, Iran", "abstract": "Digital Elevation Models (DEMs) play a significant role in hydraulic modeling and flood risk management. This study initially investigated the effect of Unmanned Aerial Vehicle (UAV) DEM resolutions, ranging from 1 m to 30 m, on flood characteristics, including the inundation area, mean flow depth, and mean flow velocity. Then, the errors of flood characteristics for global DEMs, comprising ALOS (30 m), ASTER (30 m), SRTM (30 m), and TDX (12 m) were quantified using UAV DEM measurements. For these purposes, the HEC-RAS 2D model in steady-state conditions was used to simulate the flood with return periods of 5- to 200 years along 20 km reach of Atrak River located in northeastern Iran. Results indicated when UAV DEM resolution decreased from 1 m to 30 m, inundation area and mean flow depth increased 17.0% (R2 = 0.94) and 10.2% (R2 = 0.96) respectively, while mean flow velocity decreased 16.8% (R2 = 0.94). Validation of the hydraulic modeling using the modified normalized difference water index demonstrated that the HEC-RAS 2D model in conjunction with UAV DEM simulates the flood with 92% accuracy. Comparing the global DEMs with UAV DEM showed that the root mean square error (RMSE) values of the flow depth for ASTER, SRTM, ALOS, and TDX DEMs were 1.77, 1.12, 1.02, and 0.93 m, and the RMSE values of the flow velocity for the same DEMs were 0.81, 0.66, 0.55, and 0.47 m/s, respectively. Furthermore, TDX DEM with a 6.15% error in the inundation area was the nearest to UAV measurements. Overall, TDX DEM revealed a better performance in hydraulic modeling of the fluvial flood characteristics. Hence, it is recommended for environments where high-resolution topography data is scarce. The results of this study could potentially serve as a guideline for selecting global DEMs for hydraulic simulations.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1038/S41598-022-06801-8", "year": 2022, "title": "Realizing the full reservoir operation potential during the 2020 Yangtze river floods", "abstract": "Five severe floods occurred in the Yangtze River Basin, China, between July and August 2020, and the Three Gorges Reservoir (TGR) located in the middle Yangtze River experienced the highest inflow since construction. The worlds largest cascade-reservoir group, which counts for 22 cascade reservoirs in the upper Yangtze River, cooperated in real time to control floods. The cooperation prevented evacuation of 600,000 people and extensive inundations of farmlands and aquacultural areas. In addition, no water spillage occurred during the flood control period, resulting in a world-record annual output of the TGR hydropower station. This work describes decision making challenges in the cooperation of super large reservoir groups based on a case-study, controlling the 4th and 5th floods (from Aug-14 to Aug-22), the efforts of technicians, multi-departments, and the state, and reflects on these. To realize the full potential of reservoir operation for the Yangtze River Basin and other basins with large reservoir groups globally, we suggest: (i) improve flood forecast accuracy with a long leading time; (ii) strengthen and further develop ongoing research on reservoir group cooperation; and (iii) improve and implement institutional mechanisms for coordinated operation of large reservoir groups.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/NHESS-20-1415-2020", "year": 2020, "title": "Brief communication: Comparing hydrological and hydrogeomorphic paradigms for global flood hazard mapping", "abstract": "Abstract. Global floodplain mapping has rapidly progressed over the past few years. Different methods have been proposed to identify areas prone to river flooding, resulting in a plethora of available products. Here we assess the potential and limitations of two main paradigms and provide guidance on the use of these global products in assessing flood risk in data-poor regions.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.RSE.2022.113077", "year": 2022, "title": "Towards a global seasonal and permanent reference water product from Sentinel-1/2 data for improved flood mapping", "abstract": "Satellite-based flood mapping has become an important part of disaster response. In order to accurately distinguish flood inundation from normally present conditions, up-to-date, high-resolution information on the seasonal water cover is crucial. This information is usually neglected in disaster management, which may result in a non-reliable representation of the flood extent, mainly in regions with highly dynamic hydrological conditions. In this study, we present a fully automated method to generate a global reference water product specifically designed for the use in global flood mapping applications based on high resolution Earth Observation data. The proposed methodology combines existing processing pipelines for flood detection based on Sentinel-1/2 data and aggregates permanent as well as seasonal water masks over an adjustable reference time period. The water masks are primarily based on the analysis of Sentinel-2 data and are complemented by Sentinel-1-based information in optical data scarce regions. First results are demonstrated in five selected study areas (Australia, Germany, India, Mozambique, and Sudan), distributed across different climate zones and are systematically compared with external products. Further, the proposed product is exemplary applied to three real flood events in order to evaluate the impact of the used reference water mask on the derived flood extent. Results show, that it is possible to generate a consistent reference water product at 1020 m spatial resolution, that is more suitable for the use in rapid disaster response than previous masks. The proposed multi-sensor approach is capable of producing reasonable results, even if only few or no information from optical data is available. Further it becomes clear, that the consideration of seasonality of water bodies, especially in regions with highly dynamic hydrological and climatic conditions, reduces potential over-estimation of the inundation extent and gives a more reliable picture on flood-affected areas.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/NHESS-22-2921-2022", "year": 2022, "title": "Brief communication: Western Europe flood in 2021 mapping agriculture flood exposure from synthetic aperture radar (SAR)", "abstract": "Abstract. In this communication, we present the exposure of agricultural lands to the flooding caused by extreme precipitation in western Europe from 12 to 15 July 2021. Overlaying the flood inundation maps derived from the near-real-time RAdar-Produced Inundation Diary (RAPID) system on the Coordination of information on the environment (CORINE) Land Cover map we estimate a 1920 km2 area affected by the flooding, with 64 % representing agricultural land. Among the inundated agricultural land, 36 % of the area is pastures while 34 % is arable land. Most agricultural flood exposure is found in eastern France along the Rhone River, the southern Netherlands along the Meuse River, and western Germany along the Rhine River.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.3390/W13101371", "year": 2021, "title": "Sustainable Management, Conservation, and Restoration of the Amazon River Delta and Amazon-Influenced Guianas Coast: A Review", "abstract": "The Amazon River delta may be currently characterized biophysically as a relatively preserved delta compared to the rampant vulnerability of many of the worlds large deltas. This status of relative preservation is reflected in a number of criteria: The still largely free-flowing nature of many of the rivers and the main stem of the Amazon that feed the delta in sediment, exceptional biodiversity, dominant shoreline accretion, and the absence of anthropogenically-generated subsidence. In this review, we show that these relatively reassuring conditions are progressively being called into question by the effects of dams on fluvial sediment supply to the delta, by increasing demographic, urban, and land development pressures in this still largely underpopulated delta, and by problems of governance that underplay aspects of basin-wide and deltaic environmental deterioration. A major challenge is that of bringing together these contrasting demands that are leading to the emergence of zones of environmental stress that test the resilience of this delta. An integral part of the strategy for the analysis of collective action, management, and conservation is that of considering the Amazon delta in terms of interacting socio-ecological systems. Pressures on the delta will be compounded in the future by decreasing fluvial sediment supply and sea-level rise. Although climate change is projected to generate surplus sediment, the rapid growth of dam constructions upstream of the delta will negatively impact the rivers sediment flux. Conservation and management of the Amazon River system aimed at keeping the delta resilient in the context of sea-level rise and reduction of sediment supply will require clear governance and better planning and anticipation, as well as socio-ecological integration. These are also requirements that will need to be implemented in the 1500 km-long coastal zone of the Guianas countries located west of the Amazon delta and the sediment dynamics and stability of which are largely determined by sediment supply from the Amazon.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2021GL092420", "year": 2021, "title": "Sea Level\u2010Driven Marsh Migration Results in Rapid Net Loss of Carbon", "abstract": "Sea level rise alters coastal carbon cycling by driving the rapid migration of coastal ecosystems, salinization of freshwater systems, and replacement of terrestrial forests with tidal wetlands. Wetland soils accumulate carbon (C) at faster rates than terrestrial soils, implying that sea level rise may lead to enhanced carbon accumulation. Here, we show that carbon stored in tree biomass greatly exceeds carbon stored in adjacent marsh soils so that marsh migration reduces total carbon stocks by \u223c50% in less than 100 years. Continued marsh soil carbon accumulation may eventually offset forest carbon loss, but we estimate that the time for replacement is similar to estimates of marsh survival (i.e., centuries), which suggests that forest C may never be replaced. These findings reveal a critical C source not included in coastal C budgets driven by migrating ecosystems and rapidly shifting allocations between carbon stored in soils and biomass.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.CSR.2020.104114", "year": 2020, "title": "Bonnet Carr\u00e9 Spillway freshwater transport and corresponding biochemical properties in the Mississippi Bight", "abstract": "Large freshwater pulses to coastal ecosystems change local hydrologic regimes and alter biogeochemical processes. The Mississippi Bight coastal ecosystem, located in the northern Gulf of Mexico shelf, is influenced by extensive freshwater inputs: the Mississippi River (MSR) and several smaller rivers to the east. Under river flood conditions, MSR waters flow through the Bonnet Carre Spillway (BCS) to relieve pressure on levees in New Orleans, Louisiana. In 2015, mild wintertime temperatures and heavy rainfall throughout the MSR watershed led to extreme flooding and prompted an unusually early BCS opening on January 10, 2016 for 23 days. This study examines the effects of such intermittent freshwater diversions on local shelf circulation, planktonic distributions, and potential contaminant transport pathways. Physical, chemical, and remote sensing data collected one month after the BCS opening suggested the region was comprised of three water masses: shelf saltwater, MSR waters, and local river waters. Observations and circulation model results showed the BCS waters remained within the estuarine lakes and sounds, where winter wind patterns mixed the waters and prevented BCS waters from flowing onto the shelf. Freshwater within the Mississippi Bight was primarily from concurrent flooding of local rivers. Two distinct clusters of microplankton (offshore versus nearshore stations) and zooplankton (Chandeleur Sound versus other stations) community compositions were detected. No algal blooms were observed during this BCS opening. The 2016 wintertime BCS opening resulted in muted effects on the sounds and shelf because of its short duration and uncharacteristically early release.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/CFT2.20132", "year": 2021, "title": "Pre\u2010emergence herbicides, not carrier volume, impacted weed management in conventional tillage systems", "abstract": "The use of pre\u2011emergence (PRE) herbicides is resurging as a standard practice for weed management in corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] in the U.S. north\u2011central region. The increased use of PRE herbicides warrants investigation on the impact of spray carrier volume on weed control. Field experiments were established at Arlington, WI, in 2018 and 2019 and Janesville, WI, in 2018 to evaluate the influence of carrier volume on weed control of PRE herbicides in conventional tilled corn and soybean. Each experiment included three PRE herbicide premixes applied at crop planting at five carrier volumes (2.5, 5, 10, 15, and 17.5 gal acre\u22121). A nontreated control was also included in the experiment. Carrier volume did not influence weed control but PRE herbicide selection did. In corn, acetochlor + clopyralid + mesotrione and bicyclopyrone + mesotrione + S\u2011metolachlor provided 10\u201313% better annual grass, common ragweed (Ambrosia artemisiifolia L.), and giant ragweed (A. trifida L.) control than fluthiacet\u2011methyl + pyroxasulfone. In soybean, dimethenamid\u2011P + saflufenacil resulted in similar common ragweed control as the flumioxazin + pyroxasulfone treatment (79\u201385%), and 6 and 14% higher annual grass control and biomass reduction, respectively, compared to metribuzin + chlorimuron\u2011ethyl at Arlington. At Janesville, due to the high giant ragweed density in soybean, all herbicide treatments provided low levels of giant ragweed control (48\u201356%). Results from these field experiments suggest that lower carrier volumes could be used for PRE herbicide applications without compromising weed control in conventional tillage systems.Core Ideas Spray carrier volume did not influence weed control of corn and soybean pre\u2011emergence herbicides in conventional tillage systems. Pre\u2011emergence herbicide selection influenced weed control in corn and soybean under conventional tillage systems. Effective pre\u2011emergence herbicides can be utilized at lower spray carrier volumes without compromising their efficacy in conventional tillage systems.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.SCITOTENV.2017.12.052", "year": 2018, "title": "Bridging the gap between terrestrial, riverine and limnological research: Application of a model chain to a mesotrophic lake in North America", "abstract": "Models remain our best available tool for managing low lake dissolved oxygen concentrations, which pose a serious ecological risk. This study investigated whether process-based catchment models (INCA-N and INCA-P) could accurately drive a lake model (PROTECH), to bridge a gap between terrestrial, riverine and limnological research. INCA was calibrated over all 20 catchments of the Simcoe watershed, Canada. Daily outputs (flow, nitrogen and phosphorus concentrations) over the period 20102016 were selected for a common baseline period, and used as inputs to PROTECH, which was calibrated across the three major basins of lake Simcoe; Kempenfelt (K42), Cooks (C9), and the main basin (E51). Results showed that at catchment outflows INCA models achieved an average flow R2 of 0.8; a load R2 of 0.7 (both for TP and N-NO3), a concentration R2 of 0.4 and 0.5 (for TP and N-NO3 respectively), and an SiO2 R2>0.8. In each basin PROTECH achieved an R2 for both temperature and dissolved oxygen (DO) concentrations of >0.9. Performance of N-NO3, TP and Chlorophyll-a concentrations were good (R2 values of up to 0.98, 0.92 and 0.53 respectively). Multi-stressor analyses established that most occurrences when DO dropped below the desired 7mg/l threshold (DO7) were attributable to combinations of high temperatures and low tributary inflows. The importance of additional drivers was depth dependent, with photosynthesis being particularly important in shallower C9 and E51 basins during summer, when algae contributed sufficient O2 to the water column to inhibit DO7 events. Conversely in the deeper more strongly stratified K42 basin, greater algal growth boosted the biochemical oxygen demand, enhancing declines in DO. Lake physics explained a significant number of DO7 events in all three basins. Integrated catchment-lake modelling approaches are important in understanding lake physical and ecological processes, and the impacts of land management and future climate change.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.160045", "year": 2023, "title": "Causes & effects of upstream-downstream flow regime alteration over Catchment-Estuary-Coastal systems", "abstract": "The construction of large dams along rivers has significantly changed the natural flow regime, reducing the inflow into many lakes and terminal wetlands. However, the question of the impact of dam operation on downstream estuarine wetlands has less been taken into account. Spatio-temporal flow regime alteration in the Mond River shows the complexity of drivers affecting the estuary-coastal system named the Mond-Protected Area in southern Iran. To this end, we applied river impact (RI) and Indicator of hydrological alteration (IHA) methods on monthly and daily river flow data across the basin. Based on the river impact method, a drastic impact below two in-operation (Tangab and Salman Farsi) dams, with RI values of 0.02 and 0.08, diminish to a severe impact with RI value of 0.35 at the last gauge (Ghantareh) on the main corridor of the Mond river due to the addition of flow from a large mid-basin (about 20,254 km2). Furthermore, the degree of hydrological alteration (daily flow analysis) at mid-stream (e.g., Dehram gauges) was similar to the unregulated upstream tributaries (e.g., Hanifaghan gauges). The remote sensing analysis in the Mond Protected Area showed the prevailing impact of sea-level rise in the Persian Gulf with the inundation of the coastal area and a shift of vegetation in a landward direction which complied with standardized precipitation index (SPI) values as a meteorological drought indicator. Thus, the consequence of climate change (e.g., sea-level rise, draught) has a higher impact on the protected area than the upstream river regulation and land-use change in the Mond basin. The holistic approach and the catchment-level study allowed us to see the complexity of the drivers influencing the estuary-coastal system.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.CRTE.2011.01.003", "year": 2011, "title": "Factors driving the biogeochemical budget of the Amazon River and its statistical modelling", "abstract": "The seasonal and interannual fluctuations of the biogeochemical budget (solutes, suspended matter, isotopes) of the Amazon River basin were analyzed, with a special focus on 44 physicochemical parameters monitored over the period 19821984 during the Carbon in the AMazon River Experiment (CAMREX) project. The relevant factors driving this variability were identified and sorted through the implementation of a statistical-regressive model coupled to variance analysis. Basically, the compositional fluctuations in the Amazon River are related (1) to the variable contribution of major tributaries (variable regional source) to the river flow but also (2) to the variable contribution of hydrological sources, (3) to river processes, i.e. in-stream diagenesis and sediment dynamics and (4) to the hydrological budget of the floodplains. Their respective contributions to the variability of chemical signals observed in the stream waters depend on which parameter was investigated but their combination explains on average 85% of the observed variability. The variability related to regional sources was captured by the compared measures of flow discharge and biogeochemical fluxes at the outlet of the major tributaries. The variability of hydrological sources was described by the variable contribution of three runoffs of distinct but constant composition: forwarded direct runoff, delayed floodplain runoff and baseflow. Several methods were tested to depict the seasonal and interannual variations of their individual discharges. Biologically-mediated processes were related to a hydrobiological index IBIO=[O2][CO2] which allows tracking the nature of the dominant ecological regime (autotrophy vs. heterotrophy). The alteration of chemical signals related to the intermittent discharge of the floodplains (where specific processes occur such as: gas exchanges at the airwater interface, sorption of dissolved organic matter, chemical weathering, deposition vs. remobilization of sediments, etc.) was simulated by taking into account the default of hydrological balance between inflows and outflows, used as a marker of floodplains discharge. This analysis shows that the chemical baseline observed in the waters of the Amazon River is mostly acquired upstream from the junction of major tributaries with the Amazon main reach.\nResume\nLes fluctuations saisonnieres et interannuelles du bilan biogeochimique (solutes, matiere particulaire, isotopes) du fleuve Amazone ont ete analysees, avec une attention particuliere apportee a 44 parametres physicochimiques mesures entre 1982 et 1984 dans le cadre du programme CAMREX. Les facteurs exercant une influence significative sur cette variabilite ont ete identifies et hierarchises par le biais dun modele statistique couple a une analyse de variance. Les variations de composition des eaux de lAmazone sont fondamentalement associees (1) a la contribution variable de ses affluents majeurs (source regionale variable) au debit total, mais aussi (2) a la contribution variable des poles de melange hydrologiques, (3) a des processus fluviaux correspondant au regime hydrobiologique et a la dynamique sedimentaire et (4) au bilan hydrologique des plaines dinondation. Leurs contributions respectives a la variabilite des signaux chimiques observes dans les eaux du fleuve dependent du parametre considere, mais leur combinaison explique en moyenne 85 % de la variabilite observee. La variabilite associee aux contributions regionales variables est apprehendee en procedant aux bilans entreessorties des debits et flux biogeochimiques. La variabilite de contribution des poles de melange est decrite par la contribution variable de trois ecoulements de compositions distinctes mais constantes : lecoulement direct a expression precoce, lecoulement local de vidange alluviale a expression differee et lecoulement de base. Douze methodes ont ete testees afin de decrire les variations saisonnieres et interannuelles des debits individuels de chaque pole de melange. Les processus controles par le vivant sont apprehendes a partir dun indice hydrobiologique IBIO=[O2][CO2] qui permet de determiner la nature du regime hydro-ecologique dominant (autotrophe vs. heterotrophe). Lalteration des signaux chimiques generee par la vidange intermittente des plaines dinondation (au niveau desquelles ont lieu des processus specifiques : echanges gazeux, sorption de matiere organique dissoute, erosion chimique, depot vs. remise en suspension de sediments, etc.) est simulee en prenant en compte le defaut de bilan hydrologique entreessorties utilise comme marqueur de debit des plaines dinondation. Cette analyse montre que le bruit de fond chimique observe dans les eaux du fleuve Amazone est principalement acquis en amont des confluences entre le troncon fluvial etudie et les principaux affluents qui lalimentent.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41467-019-11543-9", "year": 2019, "title": "Marked isotopic variability within and between the Amazon River and marine dissolved black carbon pools", "abstract": "Riverine dissolved organic carbon (DOC) contains charcoal byproducts, termed black carbon (BC). To determine the significance of BC as a sink of atmospheric CO2 and reconcile budgets, the sources and fate of this large, slow-cycling and elusive carbon pool must be constrained. The Amazon River is a significant part of global BC cycling because it exports an order of magnitude more DOC, and thus dissolved BC (DBC), than any other river. We report spatially resolved DBC quantity and radiocarbon (14C) measurements, paired with molecular-level characterization of dissolved organic matter from the Amazon River and tributaries during low discharge. The proportion of BC-like polycyclic aromatic structures decreases downstream, but marked spatial variability in abundance and 14C values of DBC molecular markers imply dynamic sources and cycling in a manner that is incongruent with bulk DOC. We estimate a flux from the Amazon River of 1.92.7 Tg DBC yr1 that is composed of predominately young DBC, suggesting that loss processes of modern DBC are important.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.AGWAT.2019.105727", "year": 2019, "title": "Dynamics of evapotranspiration over a non-irrigated alfalfa field in the Southern Great Plains of the United States", "abstract": "Accurately quantifying the dynamics of evapotranspiration (ET) is crucial for efficient water management and improved water use efficiency. However, details on the magnitudes and annual dynamics of ET with respect to environmental/biophysical factors and harvesting of hay in non-irrigated alfalfa (Medicago sativa L.) are lacking. Using the eddy covariance (EC) technique, daily magnitudes and seasonal/annual dynamics and budgets of ET were quantified from April 2016 to May 2018 over a non-irrigated alfalfa field in central Oklahoma, USA. The field was harvested periodically for hay, and cumulative dry forage yield was approximately 7.5 and 10 t ha1 in 2016 (dry year) and 2017 (wet year), respectively. Daily ET reached up to 6.9 mm d1 and 8-day average ET reached up to 5.64 mm d1. Cumulative seasonal (April-October) ET was 652 mm (1.3 times of precipitation) in 2016 and 734 mm (0.8 times of precipitation) in 2017. Annual ET in 2017 was 900 mm (0.8 times of annual precipitation). Optimum air temperature (Ta) and vapor pressure deficit (VPD) for ET were approximately 30 C and 3 kPa, respectively. Higher forage production was associated with a greater increase (22%) in carbon uptake (gross primary production, GPP) than ET (13%) in 2017 compared to 2016. Consequently, ecosystem water use efficiency (EWUE) at the seasonal scale (seasonal sums of GPP to ET) was 2.38 and 2.57 g C mm1 ET in 2016 and 2017, respectively. Despite strong correspondence (R2 = 0.73) between EC-measured ET and Moderate Resolution Imaging Spectroradiometer (MODIS)-derived ET (ETMOD16), the standard ETMOD16 product underestimated ET by 36% compared to EC-measured ET. The MODIS-derived enhanced vegetation index (EVI) and photosynthetically active radiation (PAR) explained 83% of variations in alfalfa ET, indicating the potential of integrating remote sensing observations and climate data to extrapolate site-level alfalfa ET at larger areas.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3389/FMARS.2022.1005284", "year": 2022, "title": "Characteristics of shoreline changes around the South China Sea from", "abstract": "As one of the most sensitive factors in the sealand interaction zone, the shoreline is significantly influenced by natural processes and anthropogenic activities. Monitoring long-term shoreline changes offers a basis for the integrated management and protection of coastal zones. The spatiotemporal distribution and the utilization types of shorelines had changed a lot, along with the advancement of the socioeconomics of the countries around the South China Sea (SCS) since 1980. However, the changes in shoreline characteristics for a long time around the whole SCS under anthropogenic influence remain uncertain. Using Landsat and high-resolution satellite images, this study monitored the changes in the spatial location and type of shorelines around the SCS from 1980 to 2020. Additionally, the possible reasons for the shoreline changes around the SCS were analyzed. The results showed the following: 1) the length of shorelines around the SCS maintained growth, especially in the 1990s, which increased by 734.8 km, from 28,243.8 km (1990) to 28,978.6 km (2000). 2) The proportion of natural shorelines around the SCS decreased from 92.4% to 73.3% during the past 40 years. Bedrock and mangrove shorelines disappeared most sharply by 34.2% and 21.6%, respectively. The increase of artificial shorelines was mostly driven by the expansion of constructed and aquaculture dikes. 3) The spatial location changes of most artificial shorelines can be attributed to seaward advancement, with an average advancing speed of 7.98 m/year. Of the natural shorelines, 58.4% changed in terms of their location (30.4% advancement and 28.0% retreat). Most natural shorelines around the SCS were threatened by erosion, but the extent of which was largely determined by the shorelines own stability, with less influence from the surrounding environment. Artificialization was the most prominent feature of shorelines around the SCS over the past 40 years, which was closely related to the original types of shorelines and the socioeconomic conditions of the area where they are located, and often accompanied by dramatic changes in shoreline morphology and spatial location. In addition, human interventions were not only the dominant factor in shoreline artificialization but also a major driver of natural shoreline protection.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/W14030400", "year": 2022, "title": "Long-Term Series of Chlorophyll-a Concentration in Brazilian Semiarid Lakes from Modis Imagery", "abstract": "By monitoring the chlorophyll a concentration (chla), it is possible to keep track of the eutrophication status of a lake and to describe the temporal dynamics of the phytoplankton biomass. Such monitoring must be both extensive and intensive to account for the short- and long-term biomass variations. This may be achieved by the remote estimation of chla through an orbital sensor with high temporal resolution. In this study, we used MODIS imagery to produce 21-year time series of chla for three strategic lakes of the Brazilian semi-arid region: Eng. Armando Ribeiro Goncalves, Castanhao, and Oros. We used data collected in 13 lakes of the region to test new and published regression models for chla estimation. The selected model was validated and applied to daily MODIS images for the three largest lakes. The resulting chla time series revealed that the temporal dynamics of the phytoplankton biomass is associated with the hydraulic regime of the lakes, with chla plummeting upon intense water renewal and keeping high during persistent dry periods. The intense rainy season of 2004 reduced the phytoplankton biomass and its effects even extended to the subsequent years. Our results encourage the exploration of the MODIS archived imagery in limnological studies.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41598-021-92729-4", "year": 2021, "title": "Identifying ENSO-related interannual and decadal variability on terrestrial water storage", "abstract": "We apply two statistical techniques to satellite measurements to identify a relationship between terrestrial water storage (TWS) and El Nino-Southern Oscillation (ENSO). First, we modified and used the least-squares regression of a previous study using longer records. Second, we applied a cyclostationary empirical orthogonal function analysis (CSEOF). Although the CSEOF technique is distinct from the least-squares regression in that it does not consider proxies, each method produces two modes (decadal and interannual), showing consistency with each technique in spatial pattern and its evolution amplitudes. We also compared the results obtained by the two methods for thirty watersheds, of which five watersheds were compared with previous studies. The combination of the two modes explains the total variance in most watersheds showing the role that interannual and decadal ENSO-related signals in understanding terrestrial water storage variability. The results show that the decadal mode, along with the interannual mode, also plays an important role in describing the local TWS.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41612-022-00250-W", "year": 2022, "title": "The underappreciated role of anthropogenic sources in atmospheric soluble iron flux to the Southern Ocean", "abstract": "The atmospheric deposition of soluble (bioaccessible) iron enhances ocean primary productivity and subsequent atmospheric CO2 sequestration in iron-limited ocean basins, especially the Southern Ocean. While anthropogenic sources have been recently suggested to be important in some northern hemisphere oceans, the role in the Southern Ocean remains ambiguous. By comparing multiple model simulations with the new aircraft observations for anthropogenic iron, we show that anthropogenic soluble iron deposition flux to the Southern Ocean could be underestimated by more than a factor of ten in previous modeling estimates. Our improved estimate for the anthropogenic iron budget enhances its contribution on the soluble iron deposition in the Southern Ocean from about 10% to 60%, implying a dominant role of anthropogenic sources. We predict that anthropogenic soluble iron deposition in the Southern Ocean is reduced substantially (3090%) by the year 2100, and plays a major role in the future evolution of atmospheric soluble iron inputs to the Southern Ocean.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.EPSL.2021.117341", "year": 2022, "title": "Controlling factors and impacts of river-borne neodymium isotope signatures and rare earth element concentrations supplied to the Canadian Arctic \u2026", "abstract": "Determining the factors controlling the neodymium (Nd) isotopic compositions (expressed as Nd) and rare earth element (REE) concentrations of rivers is imperative to improve our understanding of the distribution of these water mass tracers in the ocean. Here we present the first measurements of <0.45 m-filtrate REE concentrations (i.e., the concentration of truly dissolved, nano-particulate and colloidal REEs passing through a 0.45 m filter, hereafter referred to as dissolved) and Nd in rivers draining into the Canadian Arctic Archipelago (CAA). Results show a large variation in both REE concentrations (Nd=[8;37,260] pmol/kg) and Nd ([32.1;15.1]) in the thirteen rivers sampled. Dissolved REE concentrations increase with increasing fractions of metamorphic rocks and ice cover in the rivers' watersheds, while Nd and PAAS-normalized REE patterns are inherited from the watershed's bedrock lithology. The four rivers draining watersheds composed of Precambrian metamorphic rocks exhibit the highest REE concentrations, the least radiogenic Nd, and shale-normalized patterns enriched in light REEs. The remaining nine rivers drain mainly or exclusively sedimentary bedrock and have lower REE concentrations, more radiogenic Nd and generally show heavy REE enrichment, with variable negative cerium (Ce) anomalies. The presence of ice sheets in the drainage area, and the ionic strength, pH, and dissolved organic carbon concentration of river water are the main factors determining riverine dissolved REE concentrations by controlling the formation and stabilization of colloids. We estimate a flow of dissolved Nd transported by Arctic rivers discharging into the CAA equivalent to the Nd flux of seawater entering the CAA. Depending on the percentage of Nd removal during mixing with seawater, the impact of river water on the Nd of seawater exiting the CAA could be modest (if 90% removal) or more significant (if 90% removal). This riverine contribution could potentially impart a climate-sensitive Nd signature to the seawater reaching Baffin Bay, with possible implications for the use of Nd in paleoceanographic reconstructions of water mass distribution.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S40899-020-00357-Z", "year": 2020, "title": "Multi-tracer (\u03b418O, \u03b4D, 3H, CFCs and SF6) investigation of groundwater recharge and apparent age at the Bamenda Highlands along the Cameroon volcanic line", "abstract": "The Bamenda Highlands contains numerous dilute and soda springs of unknown hydrological provenance. These dilute springs are a vital source of drinking water to the inhabitants. As a contribution to water management, this study investigated the spring water recharge, residence time and sub-surface circulation using 18O, D, 3H, CFCs, SF6 and TDS. A plot of both water types along the local meteoric water line indicated the meteoric origin and rapid recharge following precipitation. Dilute springs with a 18O altitude effect of 0.27/100 m suggested recharge at different elevations. The CFC-12, CFC-11 and CFC-113 dating (complemented by 3H) showed reasonable young apparent ages of dilute springs ranging from 21 to > 52 (mean/median of 25) years and old soda springs (> 52 years). SF6 concentrations in dilute springs revealed exceptionally young ages relative to CFCs modelled ages suggesting a terrigenous enrichment of the former. Thus, groundwater dating with SF6 is unreliable in the area. Besides the old apparent ages of soda springs, their highly depleted 18O and high TDS (mean of 1396 mg/l) indicated palaeo-recharge and high waterrock interaction, respectively. In contrast, the low TDS of dilute springs (", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2020.125047", "year": 2020, "title": "Importance of nutrient loading and irrigation in gross primary productivity trends in India", "abstract": "Investigating the effects of various environmental factors on gross primary productivity (GPP) is crucial for quantifying the carbon exchange between the atmosphere and the terrestrial vegetation for managing climate change. Although it is well known that various natural and anthropogenic factors (e.g., climate change, agricultural activities, and atmospheric CO2 concentration change) can alter GPP, their relative influences are not clearly understood in every region. In this study, we consider several factors and investigate their roles in increasing the GPP in large parts of India. We considered about three decades (1980s to late 2000s) of GPP data and use a regression based systematic approach to find out the most likely cause explaining the trends in India. This study suggests that the common suspects like CO2 and climate may have limited influence on the GPP trends in India when compared to anthropogenic influences. Our results instead support the notion that GPP trends in India are mainly shaped by agricultural activities through nutrient loading (R2=0.68) and irrigation (R2=0.1). Overall, our study reveals the potential of agricultural activities in altering the carbon budget of a region.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3389/FEART.2021.676748", "year": 2021, "title": "Advances in amazonian peatland discrimination with multi-temporal PALSAR Refines estimates of Peatland distribution, C stocks and deforestation", "abstract": "There is a data gap in our current knowledge of the geospatial distribution, type and extent of C rich peatlands across the globe. The Pastaza Maranon Foreland Basin (PMFB), within the Peruvian Amazon, is known to store large amounts of peat, but the remoteness of the region makes field data collection and mapping the distribution of peatland ecotypes challenging. Here we review methods for developing high accuracy peatland maps for the PMFB using a combination of multi-temporal synthetic aperture radar (SAR) and optical remote sensing in a machine learning classifier. The new map produced has 95% overall accuracy with low errors of commission (16%) and errors of omission (015%) for individual peatland classes. We attribute this improvement in map accuracy over previous maps of the region to the inclusion of high and low water season SAR images which provides information about seasonal hydrological dynamics. The new multi-date map showed an increase in area of more than 200% for pole forest peatland (6% error) compared to previous maps, which had high errors for that ecotype (2036%). Likewise, estimates of C stocks were 35% greater than previously reported (3.238 Pg in\r\n Draper et al. (2014)\r\n to 4.360 Pg in our study). Most of the increase is attributed to pole forest peatland which contributed 58% (2.551 Pg) of total C, followed by palm swamp (34%, 1.476 Pg). In an assessment of deforestation from 2010 to 2018 in the PMFB, we found 89% of the deforestation was in seasonally flooded forest and 43% of deforestation was occurring within 1 km of a river or road. Peatlands were found the least affected by deforestation and there was not a noticeable trend over time. With development of improved transportation routes and population pressures, future land use change is likely to put South American tropical peatlands at risk, making continued monitoring a necessity. Accurate mapping of peatland ecotypes with high resolution (<30 m) sensors linked with field data are needed to reduce uncertainties in estimates of the distribution of C stocks, and to aid in deforestation monitoring.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S12665-018-7851-2", "year": 2018, "title": "Change in carbon flux (1960\u20132015) of the Red River (Vietnam)", "abstract": "Global riverine carbon concentrations and fluxes have been impacted by climate and human-induced changes for many decades. This paper aims to reconstruct the longterm carbon concentrations and carbon fluxes of the Red River, a system under the coupled pressures of environmental change and human activity. Based on (1) the relationships between particulate and dissolved organic carbon (POC, DOC) or dissolved inorganic carbon (DIC), and suspended sediments (TSS) or river water discharge and on (2) the available detailed historical records of river discharge and TSS concentration, the variations of the Red River carbon concentration and flux were estimated for the period 19602015. The results show that total carbon flux of the Red River averaged 2555 639 kton C year1. DIC fluxes dominated total carbon fluxes, representing 64% of total, reflecting a strong weathering process from carbonate rocks in the upstream basin. Total carbon fluxes significantly decreased from 2816 kton C year1 during the 1960s to 1372 kton C year1 during the 2010s and showed clear seasonal and spatial variations. Organic carbon flux decreased in both quantity and proportion of the total carbon flux from 40.9% in 1960s to 14.9% in 2010s, reflecting the important impact of dam impoundment. DIC flux was also reduced over this period potentially as a consequence of carbonate precipitation in the irrigated, agricultural land and the reduction of the Red River water discharge toward the sea. These decreases in TSS and carbon fluxes are probably partially responsible for different negatives impacts observed in the coastal zone.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1088/1748-9326/AC78F8", "year": 2022, "title": "Satellite observed recent rising water levels of global lakes and reservoirs", "abstract": "Abstract\r\n \r\n Monitoring global lake/reservoir water level changes is needed to understand the global water cycle and investigate its potential drivers. The existing global water level products only cover lakes/reservoirs with large sizes (>100 km\r\n 2\r\n ). Here, Ice, Cloud, and land Elevation Satellite (ICESat) and ICESat-2 altimetry data with small footprints are employed to examine global water level changes for 22 008 lakes/reservoirs greater than 1 km\r\n 2\r\n . We report that 77.56% of them exhibited rising water levels over 20032021. Across the globe, 78.84% of lakes exhibit a rising water level, while the proportion for reservoirs is only 56.01%. Global lake/reservoir is estimated to experience a median water level change rate of +0.02 0.02 m yr\r\n 1\r\n over 20032021, and lakes have a larger water level rise (+0.02 0.02 m yr\r\n 1\r\n ) than reservoirs (+0.008 0.14 m yr\r\n 1\r\n ). We detect large-scale rising water levels in the Tibetan Plateau, the Mississippi River basin, and high-latitude regions of the Northern Hemisphere. Our calculation also suggests a negative relationship between the percentage of water level rise in lakes/reservoirs and population density for global river basins (\r\n r\r\n = 0.41,\r\n p\r\n -value < 0.05) and 11 hotspots (\r\n r\r\n = 0.48,\r\n p\r\n -value < 0.05). Our result suggests that inland water level has tended to rise in recent years under natural processes while human activities (i.e. with higher population density) can balance the water level rise via reservoir regulation. We find the existing datasets underestimated global water level rise, which may be caused by the exclusion of numerous small lakes/reservoirs. Our estimated global water level change rates (that include numerous small lakes with areas of 110 km\r\n 2\r\n ) can improve the understanding of global hydrological cycle and water resource management under the double pressure of climate warming and human activities.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1088/1748-9326/AB5CA8", "year": 2019, "title": "Can multi-strategy management stabilize nitrate leaching under increasing rainfall?", "abstract": "Abstract\r\n \r\n The increased spring rainfall intensity and amounts observed recently in the US Midwest poses additional risk of nitrate (NO\r\n 3\r\n ) leaching from cropland, and contamination of surface and subsurface freshwater bodies. Several individual strategies can reduce NO\r\n 3\r\n loading to freshwater ecosystems (i.e. optimize N fertilizer applications, planting cover crops, retention of active cycling N), but the potential for synergistic interactions among N management practices has not been fully examined. We applied portfolio effect (PE) theory, a concept originally developed for financial asset management, to test whether implementing multiple N management practices simultaneously produces more stable NO\r\n 3\r\n leaching mitigation outcomes than what would be predicted from implementing each practice independently. We analyzed simulated data generated using a validated process-based cropping system model (APSIM) that covers a range of soils, weather conditions, and management practices. Results indicated that individual management practices alone explained little of the variation in drainage NO\r\n 3\r\n loads but were more influential in the amount of residual soil NO\r\n 3\r\n at crop harvest. Despite this, we observed a general stabilizing effect from adopting well-designed multi-strategy approaches for both NO\r\n 3\r\n loads and soil NO\r\n 3\r\n at harvest, which became more pronounced in years with high spring rainfall. We use the PE principle to design multi-strategy management to reduce and stabilize NO\r\n 3\r\n leaching, which resulted in 9.6% greater yields, 15% less NO\r\n 3\r\n load, and 61% less soil NO\r\n 3\r\n at harvest than the baseline typical management. Our results make the case for applying the PE to adapt NO\r\n 3\r\n leaching mitigation to increased climate variability and change, and guide policy action and on-the-ground implementation.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1038/S41598-020-80160-0", "year": 2021, "title": "Elevated radium levels in Nubian Aquifer groundwater of Northeastern Africa", "abstract": "The Nubian Sandstone Aquifer System in Northeast Africa and the Middle East is a huge water resource of inestimable value to the population. However, natural radioactivity impairs groundwater quality throughout the aquifer posing a radiological health risk to millions of people. Here we present measurements of radium isotopes in Nubian Aquifer groundwater from population centers in the Western Desert of Egypt. Groundwater has 226Ra and 228Ra activities ranging from 0.01 to 2.11 and 0.03 to 2.31 Bq/L, respectively. Most activities (combined 226Ra + 228Ra) exceed U.S. EPA drinking water standards. The estimated annual radiation doses associated with ingestion of water having the highest measured Ra activities are up to 138 and 14 times the WHO-recommended maxima for infants and adults, respectively. Dissolved Ra activities are positively correlated with barium and negatively correlated with sulfate, while barite is approximately saturated. In contrast, Ra is uncorrelated with salinity. These observations indicate the dominant geochemical mechanisms controlling dissolved Ra activity may be barite precipitation and sulfate reduction, along with input from alpha-recoil and dissolution of aquifer minerals and loss by radioactive decay. Radium mitigation measures should be adopted for water quality management where Nubian Aquifer groundwater is produced for agricultural and domestic consumption.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/S40899-020-00440-5", "year": 2020, "title": "New insights on the classification of major Amazonian river water types", "abstract": "Traditional water classifications for Amazonian rivers are based mainly on optical characteristics that do not fully capture their complexity. Today, an increasing amount of hydrochemical data indicates that the chemical composition of Amazonian rivers varies much more than this simple classification indicates. Revising river classification based on hydrochemical properties is proposed here. In this first comprehensive review of Amazonian river chemistry, we synthesized critical information from 168 scientific publications and distinguish unusual white, black, and clearwater rivers. It is shown the distribution of such rivers across the basin and the limitations of using generalized designations for river typologies. For example, some optically clearwater rivers draining carboniferous stripes have chemical properties similar to whitewater rivers, regardless of their high transparency. Furthermore, a clear or blackwater stream that becomes turbid because of soil erosion does not become a whitewater stream. Its hydrochemical parameters of acidity and nutrient poverty depend on the geology of the catchment area and remain relatively unaffected. These insights into Amazonian river classification provide a new understanding of their baseline limnological conditions. They have implications for sustainable management of freshwater systems and for monitoring potential impacts of large development projects and climate change on the Amazonian aquatic systems.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/RS10050793", "year": 2018, "title": "On the Desiccation of the South Aral Sea Observed from Spaceborne Missions", "abstract": "The South Aral Sea has been massively affected by the implementation of a mega-irrigation project in the region, but ground-based observations have monitored the Sea poorly. This study is a comprehensive analysis of the mass balance of the South Aral Sea and its basin, using multiple instruments from ground and space. We estimate lake volume, evaporation from the lake, and the Amu Darya streamflow into the lake using strengths offered by various remote-sensing data. We also diagnose the attribution behind the shrinking of the lake and its possible future fate. Terrestrial water storage (TWS) variations observed by the Gravity Recovery and Climate Experiment (GRACE) mission from the Aral Sea region can approximate water level of the East Aral Sea with good accuracy (1.8% normalized root mean square error (RMSE), and 0.9 correlation) against altimetry observations. Evaporation from the lake is back-calculated by integrating altimetry-based lake volume, in situ streamflow, and Global Precipitation Climatology Project (GPCP) precipitation. Different evapotranspiration (ET) products (Global Land Data Assimilation System (GLDAS), the Water Gap Hydrological Model (WGHM)), and Moderate-Resolution Imaging Spectroradiometer (MODIS) Global Evapotranspiration Project (MOD16) significantly underestimate the evaporation from the lake. However, another MODIS based Priestley-Taylor Jet Propulsion Laboratory (PT-JPL) ET estimate shows remarkably high consistency (0.76 correlation) with our estimate (based on the water-budget equation). Further, streamflow is approximated by integrating lake volume variation, PT-JPL ET, and GPCP datasets. In another approach, the deseasonalized GRACE signal from the Amu Darya basin was also found to approximate streamflow and predict extreme flow into the lake by one or two months. They can be used for water resource management in the Amu Darya delta. The spatiotemporal pattern in the Amu Darya basin shows that terrestrial water storage (TWS) in the central region (predominantly in the primary irrigation belt other than delta) has increased. This increase can be attributed to enhanced infiltration, as ET and vegetation index (i.e., normalized difference vegetation index (NDVI)) from the area has decreased. The additional infiltration might be an indication of worsening of the canal structures and leakage in the area. The study shows how altimetry, optical images, gravimetric and other ancillary observations can collectively help to study the desiccating Aral Sea and its basin. A similar method can be used to explore other desiccating lakes.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3389/FEART.2020.00197", "year": 2020, "title": "Determining the pace and magnitude of lake level changes in Southern Ethiopia over the last 20,000 years using lake balance modeling and SEBAL", "abstract": "The Ethiopian rift is known for its diverse landscape, ranging from arid and semi-arid savannahs to high and humid mountainous regions. Lacustrine sediments and paleo-shorelines indicate water availability fluctuated dramatically from deep fresh water lakes, to shallow highly alkaline lakes, to completely desiccated lakes. To investigate the role lakes have played through time as readily available water sources to humans, an enhanced knowledge of the pace, character and magnitude of these changes is essential. Hydro-balance models are used to calculate paleo-precipitation rates and the potential pace of lake level changes. However, previous models did not consider changes in hydrological connectivity during humid periods in the rift system, which may have led to an overestimation of paleo-precipitation rates. Here we present a comprehensive hydro-balance modeling approach that simulates multiple rift lakes from the southern Ethiopian Rift (lakes Abaya, Chamo, and paleo-lake Chew Bahir) simultaneously, considering their temporal hydrological connectivity during high stands of the African Humid Period (AHP, ~155 ka). We further used the Surface Energy Balance Algorithm for Land (SEBAL) to calculate the evaporation of paleo-lake Chew Bahir's catchment. We also considered the possibility of an additional rainy season during the AHP as previously suggested by numerous studies. The results suggest that an increase in precipitation of 2030% throughout the southern Ethiopian Rift is necessary to fill paleo-lake Chew Bahir to its overflow level. Furthermore, it was demonstrated that paleo-lake Chew Bahir was highly dependent on the water supply from the upper lakes Abaya and Chamo and dries out within ~40 years if the hydrological connection is cut off and the precipitation amount decreases to present day conditions. Several of such rapid lake level fluctuations, from a freshwater to a saline lake, might have occurred during the termination of the AHP, when humid conditions were less stable. Fast changes in fresh water availability requires high adaptability for humans living in the area and might have exerted severe environmental stress on humans in a sub-generational timescale.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.SCITOTENV.2017.08.003", "year": 2018, "title": "Data-driven analysis of nutrient inputs and transfers through nested catchments", "abstract": "A data-driven screening methodology is developed for estimating nutrient input and retention-delivery in catchments with measured water discharges and nutrient concentrations along the river network. The methodology is applied to the Sava River Catchment (SRC), a major transboundary catchment in southeast Europe, with seven monitoring stations along the main river, defining seven nested catchments and seven incremental subcatchments that are analysed and compared in this study. For the relatively large nested catchments (>40,000km2), characteristic regional values emerge for nutrient input per unit area of around 30T/yr/km2 for dissolved inorganic nitrogen (DIN) and 2T/yr/km2 for total phosphorus (TP). For the smaller nested catchments and incremental subcatchments, corresponding values fluctuate and indicate hotspot areas with total nutrient inputs of 158T/yr/km2 for DIN and 13T/yr/km2 for TP. The delivered fraction of total nutrient input mass (termed delivery factor) and associated nutrient loads per area are scale-dependent, exhibiting power-law decay with increasing catchment area, with exponents of around 0.20.3 for DIN and 0.30.5 for TP. For the largest of the nested catchments in the SRC, the delivery factor is around 0.08 for DIN and 0.03 for TP. Overall, the nutrient data for nested catchments within the SRC show consistency with previously reported data for multiple nested catchments within the Baltic Sea Drainage Basin, identifying close nutrient relationships to driving hydro-climatic conditions (runoff for nutrient loads) and socio-economic conditions (population density and farmland share for nutrient concentrations).", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.3389/FMARS.2022.949034", "year": 2022, "title": "Arctic biogeochemical and optical properties of dissolved organic matter", "abstract": "Arctic landscapes are warming and becoming wetter due to changes in precipitation and the timing of snowmelt which consequently alters seasonal runoff and river discharge patterns. These changes in hydrology lead to increased mobilization and transport of terrestrial dissolved organic matter (DOM) to Arctic coastal seas where significant impacts on biogeochemical cycling can occur. Here, we present measurements of dissolved organic carbon (DOC) and chromophoric DOM (CDOM) in the Yukon River-to-Bering Sea system and two river plumes on the Alaska North Slope which flow into the Beaufort Sea. Our sampling characterized optical and biogeochemical properties of DOM during high and low river discharge periods for the Yukon River-Bering Sea system. The average DOC concentration at the multiple Yukon River mouths ranged from a high of 10.36 mg C L\r\n -1\r\n during the ascending limb of the 2019 freshet (late May), 6.4 mg C L\r\n -1\r\n during the descending limb of the 2019 freshet (late June), and a low of 3.86 mg C L\r\n -1\r\n during low river discharge in August 2018. CDOM absorption coefficient at 412 nm (\r\n a\r\n CDOM\r\n (412)) averaged 8.23 m\r\n -1\r\n , 5.07 m\r\n -1\r\n , and 1.9 m\r\n -1\r\n , respectively. Several approaches to model DOC concentration based on its relationship with CDOM properties demonstrated cross-system seasonal and spatial robustness for these Arctic coastal systems despite spanning an order of magnitude decrease in DOC concentration from the lower Yukon River to the Northern Bering Sea as well as the North Slope systems. Snapshot fluxes of DOC and CDOM across the Yukon River Delta to Norton Sound were calculated from our measurements and modeled water fluxes forced with upstream USGS river gauge data. Our findings suggest that during high river flow, DOM reaches the delta largely unaltered by inputs or physical and biogeochemical processing and that the transformations of Yukon River DOM largely occur in the plume. However, during low summer discharge, multiple processes including local precipitation events, microbial decomposition, photochemistry, and likely others can alter the DOM properties within the lower Yukon River and Delta prior to flowing into Norton Sound.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.2166/WPT.2022.121", "year": 2022, "title": "Understanding short-term organic matter fluctuations to optimize drinking water treatment", "abstract": "Increases in organic content and the resulting browning of freshwater are a current and growing challenge for the ecology of these waters, leading to the need for more efforts in drinking water production. This study investigated the implications of short-term changes in the water quality from Lake Bolmen on the treatment process at the downstream located at the Ringsjo water treatment plant. The main objective was to understand short-term organic matter fluctuations to efficiently manage drinking water treatment. The ability to make predictions about expected raw water quality based on variations in the watershed and upstream waters facilitates optimal adjustment of drinking water treatment processes. Key elements in the water supply system studied included a tunnel and pipeline system and a sub-basin of Lake Bolmen. A wealth of data were available for the analysis to establish temporal and spatial properties of the water quality in the system and its dependence on the governing factors. The main factors controlling water quality were identified, both regarding the transport in the tunnel and through the sub-basin, including surface runoff, hydrodynamic properties, sedimentation, resuspension, and biomass availability. Although a particular case was investigated, the study has implications for improving drinking water treatment.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.150435", "year": 2022, "title": "Contrasting land-uses in two small river basins impact the colored dissolved organic matter concentration and carbonate system along a river-coastal ocean \u2026", "abstract": "Human activities have led to an increase in land use change, with effects on the structure and functioning of ecosystems. The impact of contrasting land uses along river basins on the concentration of colored dissolved organic matter (CDOM) reaching the coastal zone, and its relationship with the carbonate system of the adjacent coastal ocean, is poorly known. To understand the relationship between land use change, CDOM and its influence on the carbonate system, two watersheds with contrasting land uses in southern Chile were studied. The samples were collected at eight stations between river and adjacent coastal areas, during three sampling campaigns in the austral summer and spring. Chemical and biological samples were analyzed in the laboratory according to standard protocols. Landsat 8 satellite images of the study area were used for identification and supervised classification using remote sensing tools. The Yaldad River basin showed 82% of native forest and the Colu River basin around 38% of grassland (agriculture). Low total alkalinity (AT) and Dissolved Inorganic Carbon (DIC), but high CDOM proportions were typically observed in freshwater. A higher CDOM and humic-like compounds concentration was observed along the river-coastal ocean continuum in the Yaldad basin, characterized by a predominance of native forests. In contrast, nutrient concentrations, AT and DIC, were higher in the Colu area. Low CaCO3 saturation state (Ar ", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.WATRES.2021.117905", "year": 2022, "title": "Transport and transformation of dissolved inorganic carbon in a", "abstract": "Most reservoirs in subtropical areas experience periodic variations in the thermal structure of their water columns, with times of strong thermal stratification being succeeded by periods of mixing, over the course of the year. Understanding of the transport and transformation of dissolved inorganic carbon over such thermal cycles in artificial reservoirs remains poor. To address this problem, this study examined the spatiotemporal behavior of dissolved inorganic carbon (DIC), the partial pressure of CO2 (pCO2), carbon isotope ratios (\u03b413 CDIC), and CO2 emission (FCO2), from 2014 to 2018 in a subtropical, groundwater-fed reservoir in southern China. It was found that CO2 emissions during mixing periods are much higher than in thermally stratified periods (particularly during transition from stratified to mixing) as a result of upwelling and release of dissolved CO2 (CO2aq) accumulated in the hypolimnion. CO2 emission fluxes at the water-gas interface accounted for only a small proportion of the DIC in the reservoir. The relationships between of DIC and \u03b413 CDIC displayed two distinct modes, due to spatial differences in water depths and to strong thermal stratification during warmer seasons: (1) DIC concentrations increase and \u03b413 CDIC values decrease from epilimnion to hypolimnion, and (2) \u03b413 CDIC values decrease with increasing DIC concentrations but \u03b413 CDIC is progressively enriched near the bottom during periods of thermal stratification. In addition, this study found three distinct processes of DIC accumulation and consumption in the reservoir: (1) DIC accumulated in the hypolimnion during thermal stratification periods, due to carbon retention but (2) DIC was substantially consumed in the epilimnion during such periods, and (3) average DIC concentrations and pCO2 increased significantly from upstream to downstream along the reservoir, while average \u03b413 CDIC values became lighter. These results highlight that carbon behavior in groundwater\u2011fed reservoirs is often controlled by a combination of biogeochemical processes and seasonal variations in thermal structure. Sampling and monitoring strategies should consider these factors in order to accurately estimate carbon budgets in reservoirs, lakes or ponds.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11269-019-02468-5", "year": 2020, "title": "Assessment of Water Storage Changes Using GRACE and GLDAS", "abstract": "Water crisis is one of the main global risks that has different impacts on the society. This work uses available data and tools to track water storage changes in Iran, where lack of observations limits hydroclimatological studies and thus causes disasters. Data from Global Land Data Assimilation System (GLDAS) and Gravity Recovery and Climate Experiment (GRACE) are combined to analyze water storage changes (LWE) in Iran. GRACE signals indicate a large reduction of the water storage in North of Iran along the coast of the Caspian Sea (the largest global inland water body), where the water level has been oscillating significantly. In addition, results show the largest reduction of the water storage that occurred in the karstic and alluvial aquifers in Zagros, where groundwater is overused and many dams are constructed across the rivers. In addition to anthropogenic forcing, climate change has short- and long-term impact on the water storage. The highest correlation between LWE and climatological variables including temperature and precipitation is at 3- and 2-month lags, respectively. Natural and anthropogenic forcing caused the maximum rate of LWE reduction (maximum average reduction) in Kermanshah province, where a sequence of earthquakes occurred (in 2017, 2018, and 2019). Results highlight the main role of water storage monitoring in management plans and decision-making processes to conserve natural resources and reduce hazards.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ENVSOFT.2022.105344", "year": 2022, "title": "Can a simple water quality model effectively estimate runoff-driven nutrient loads to estuarine systems? A national-scale comparison of STEPLgrid and SPARROW", "abstract": "This study investigated whether a simple model could scale across watersheds and effectively predict runoff-driven nutrient loading as compared to a model with more complex process representation. A lumped model, the Spreadsheet Tool for Estimating Pollutant Load (STEPL), was adapted to use gridded data (STEPLgrid) and applied to 112 coastal watersheds across the Atlantic, Gulf, and Pacific coasts of the contiguous United States (U.S.) to estimate annual runoff-driven total nitrogen (TN) and total phosphorus (TP) loads. STEPLgrid outputs were compared to those of the SPAtially Referenced Regression on Watershed Attributes (SPARROW) model. Relative to SPARROW, STEPLgrid produced comparable estimates of TN and TP loads for most watersheds studied and its predicted loads were more similar to SPARROW for TN than TP. STEPLgrid was particularly effective at rank-ordering watersheds by TN and TP loads as compared to SPARROW, indicating that STEPLgrid was useful for relative comparisons across diverse watersheds.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.JHYDROL.2021.126422", "year": 2021, "title": "Modelling framework for flow, sediments and nutrient loads in a large transboundary river watershed: A climate change impact assessment of the Nemunas \u2026", "abstract": "This study provides an in-depth analysis of the Nemunas River watershed, situated in the Baltic Sea basin, and possible future changes to the stream flow, hydrologic regime, sediment (SS), Total Nitrogen (TN) and Total Phosphorus (TP) load from the river to the Curonian Lagoon under different climate change scenarios using high-resolution modelling. The sub-regions of the watershed, represented by sub-basins of the Nemunas River tributaries and the main river branch, were modelled using the Soil and Water Assessment Tool (SWAT). The model setup was performed using the developed customizable MATLAB scripts for an advance Hydrologic Response Unit configuration and a hillslope delineation procedure. The modelling framework was used to assess the climate changes in the watershed under two future scenarios: RCP4.5 and RCP8.5, using the projected changes to precipitation, temperature, and carbon dioxide concentrations for the near-term (up to 2050) and long-term period (up to 2100) compared to the baseline period (19952010). The projections show that the annual long-term trends for flow, depending on the scenario, are small or not existing. Even if there is no visible change in trends over the years, inter-annual changes on flow, sediment and nutrient load will occur. The findings of the study suggest that the conditions of the RCP4.5 are likely to be more wet, whereas RCP8.5 will likely be drier. Most shifts will occur in the winter season, especially in January and February. A decrease in snow cover across the watershed, together with the greater frequency of soil freeze-thaw cycles can weaken the nutrient retention of soils and increase nitrogen and phosphorus losses. Coupled with the increased flows in winter, the projected nutrient load changes during winter season indicate a two-fold increase in sediment, up to 42% and 62% in TN and TP load to the Nemunas River and subsequently, to the Curonian lagoon.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.MARPOLBUL.2022.113945", "year": 2022, "title": "Sea-air transfer of a tracer dye observed during the Tracer Release", "abstract": "Rhodamine water tracer (RWT) released during the 2021 Tracer Release Experiment in the St. Lawrence Estuary provides a proxy for the water-soluble fractions of contaminant spills. Measurements of total and size-resolved aerosols were taken onboard a research vessel throughout the experiment. Size-resolved aerosol measurements show airborne transmission of water-soluble RWT in a bimodal distribution peaking at 5.2 \u03bcm and 0.9 \u03bcm. Highest aerosol RWT (30.5 pg m-3) was observed in the 12-hour daytime period following the first dye release (Sept. 5), while the lowest (8.8 pg m-3) was observed in the subsequent nighttime sample. Available wind and RWT patch information were used to identify factors contributing to the factor-of-three variation in aerosol RWT concentrations. Negligible correlations were found between aerosol RWT and wind speed and sample time-of-day. Wind direction is isolated as the key variable for consideration in identifying the impact of contaminant spills on coastal and inland communities.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.SCITOTENV.2020.142798", "year": 2021, "title": "Long-term changes in contamination and macrobenthic communities adjacent to McMurdo Station, Antarctica", "abstract": "Improved waste management at McMurdo Station, Antarctica beginning in the 1980s has been followed by decreases in polycyclic aromatic hydrocarbon (PAH) and metal contamination in the adjacent marine sediments. However, determining the effect of the decreased contamination on marine ecological indicators (macrobenthic fauna) is confounded by concurrent changes in climate cycles and other physical forces. Between 2000 and 2013, there was a decrease in concentrations of some contaminants including mercury, copper, organochlorines, and PAHs in marine sediments adjacent to McMurdo Station. PAH concentrations in Winter Quarters Bay decreased an order of magnitude from 2000/2003 to 2012/2013 and were within an order of magnitude of reference area concentrations by 2013. Macrobenthic communities did not indicate any sign of recovery and have not become more similar to reference communities over this same period of time. Temporal changes in macrobenthic community composition during the study period had higher correlations with climatic and sea ice dynamics than with changes in contaminant concentrations. The Interdecadal Pacific Oscillation climatic index had the highest correlation with macrobenthic community composition. The Antarctic Oscillation climatic index, maximum ice extent and other natural environmental factors also appear to influence macrobenthic community composition. Despite large improvements in environmental management at McMurdo Station, continuing environmental vigilance is necessary before any noticeable improvement in ecological systems is likely to occur. The effects of climate must be considered when determining temporal changes in anthropogenic effects in Antarctica. Maintaining long-term monitoring of both contaminants and ecological indicators is important for determining the localized and global influences of humans on Antarctica, which will have implications for the whole planet.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1038/S41467-020-17103-W", "year": 2020, "title": "Gainers and losers of surface and terrestrial water resources in China during 1989\u20132016", "abstract": "Data and knowledge of the spatial-temporal dynamics of surface water area (SWA) and terrestrial water storage (TWS) in China are critical for sustainable management of water resources but remain very limited. Here we report annual maps of surface water bodies in China during 19892016 at 30m spatial resolution. We find that SWA decreases in water-poor northern China but increases in water-rich southern China during 19892016. Our results also reveal the spatial-temporal divergence and consistency between TWS and SWA during 20022016. In North China, extensive and continued losses of TWS, together with small to moderate changes of SWA, indicate long-term water stress in the region. Approximately 569 million people live in those areas with deceasing SWA or TWS trends in 2015. Our data set and the findings from this study could be used to support the government and the public to address increasing challenges of water resources and security in China.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/2017GL072867", "year": 2017, "title": "Global bounds on nitrogen gas emissions from humid tropical forests", "abstract": "Denitrification and hydrologic leaching are the two major pathways by which nitrogen (N) is lost from the terrestrial biosphere. Humid tropical forests are thought to dominate denitrification losses from unmanaged lands globally, but there is large uncertainty about the range and key drivers of total N gas emissions across the biome. We combined pantropical measures of small watershed stream chemistry with ecosystem modeling to determine total N gas losses and associated uncertainty across humid tropical forests. Our calculations reveal that denitrification in soils and along hydrologic flow paths contributes on average >45% of total watershed N losses. However, when denitrification occurs exclusively in shallow soils, simulations indicate that gas emissions would exceed N inputs and render plants severely N limited, which contradicts observations of widespread N sufficiency in tropical forests. Our analyses suggest an upper bound on soil denitrification of 80% of total external N losses beyond which tropical plant growth would be compromised.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/HESS-20-4801-2016", "year": 2016, "title": "Recent trends and variability in river discharge across northern Canada", "abstract": "Abstract. This study presents an analysis of the observed inter-annual variability and inter-decadal trends in river discharge across northern Canada for 19642013. The 42 rivers chosen for this study span a combined gauged area of 5.26 106 km2 and are selected based on data availability and quality, gauged area and record length. Inter-annual variability in river discharge is greatest for the eastern Arctic Ocean (coefficient of variation, CV = 16 %) due to the Caniapiscau River diversion into the La Grande Riviere system for enhanced hydropower production. Variability is lowest for the study area as a whole (CV = 7 %). Based on the MannKendall test (MKT), no significant (p > 0.05) trend in annual discharge from 1964 to 2013 is observed in the Bering Sea, western Arctic Ocean, western Hudson and James Bay, and Labrador Sea; for northern Canada as a whole, however, a statistically significant (p < 0.05) decline of 102.8 km3 25 yr1 in discharge occurs over the first half of the study period followed by a statistically significant (p < 0.05) increase of 208.8 km3 25 yr1 in the latter half. Increasing (decreasing) trends in river discharge to the eastern Hudson and James Bay (eastern Arctic Ocean) are largely explained by the Caniapiscau diversion to the La Grande Riviere system. Strong regional variations in seasonal trends of river discharge are observed, with overall winter (summer) flows increasing (decreasing, with the exception of the most recent decade) partly due to flow regulation and storage for enhanced hydropower production along the Hudson and James Bay, the eastern Arctic Ocean and Labrador Sea. Flow regulation also suppresses the natural variability of river discharge, particularly during cold seasons.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/W12113215", "year": 2020, "title": "Identifying the Influence of Land Cover and Human Population on Chlorophyll a Concentrations Using a Pseudo-Watershed Analytical Framework", "abstract": "Increasing agricultural development and urbanization exacerbates the degradation of water quality in vulnerable freshwater systems around the world. Advances in remote sensing and greater availability of open-access data provides a valuable resource for monitoring water quality but harmonizing between databases remains a challenge. Here, we: (i) developed a pseudo-watershed analytical framework to associate freshwater lakes with adjacent land cover and human population data and (ii) applied the framework to quantify the relative influence of land cover and human population on primary production for 9313 lakes from 72 countries. We found that land cover and human population explained 30.2% of the variation in chlorophyll a concentrations worldwide. Chlorophyll a concentrations were highest in regions with higher agricultural activities and human populations. While anthropogenic land cover categories equated to only 4 of the 18 categories, they accounted for 41.5% of the relative explained variation. Applying our pseudo-watershed analytical framework allowed us to quantify the importance of land cover and human population on chlorophyll concentration for over 9000 lakes. However, this framework has broader applicability for any study or monitoring program that requires quantification of lake watersheds.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.GEOMORPH.2021.107696", "year": 2021, "title": "Avulsion of the Brahmaputra in Bangladesh during the 18th\u201319th century: A review based on cartographic and literary evidence", "abstract": "Avulsions involve switching of fluvial discharge through a new channel from an existing course and occur over varied timeframes ranging from hours to decades. With a peak discharge above 100,000 m3/s, the Brahmaputra (2900 km) is one of the largest rivers in the world. Its lower course through the GangaBrahmaputraMeghna (GBM) Delta of Bangladesh was first mapped in 176473 as a broad eastward-swinging curvature skirting the subsiding Sylhet Wetlands and falling into the Meghna River. Beginning from the late eighteenth century, the river started to avulse into a linear, more direct, southward passage into the Ganga called the Jamuna and decreased its length by 46 km (14.2%) from its former course to the Bay of Bengal. Examination of the established timeline and procedure of the avulsion event using maps and images from 176473, 183034, 185460, 190724, and 2014, in addition to evidence from contemporary literature and tree-ring reconstructed long-term discharge data, connoted certain discrepancies. Our re-evaluation indicated that the Brahmaputra shifted westward and was captured by a parallel distributary of the neighbouring Tista system initiating the switch. This was probably aided by exceptionally high monsoonal discharge between 1786 and 1790 as well as the 1787 break-in of the Tista into the Brahmaputra. Because of its high width:depth ratio and braided planform that prevented fast escape of the discharge, abandonment of the eastern channelthe Old Brahmaputraprogressed gradually; well into the next century with the new channel taking over almost completely by 185560. Comparable switchings of the Brahmaputra occurred six times in the last 11 kyr and significantly influenced development of the GBM Delta. The century-scale timeline of the last avulsion event described here refines its current understanding by proposing river capture as the mechanism of avulsion, possibly triggered by clustering of high-flood years.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1525/ELEMENTA.269", "year": 2018, "title": "River linking in India: Downstream impacts on water discharge and suspended sediment transport to deltas", "abstract": "To expand agricultural production and address water scarcity, India is moving forward with the National River Linking Project (NRLP), which will connect 44 rivers via 9,600 km of canals. Here, we compile the first complete database of proposed NRLP dams, reservoirs and canals, including operating schedules for Himalayan infrastructure. We evaluate potential NRLP-derived changes to mean annual water discharge for 29 rivers and mean monthly water and sediment discharge for six rivers flowing to five major deltas. Sediment rating curves are used to quantify the impacts of changing water discharge within the rivers, and basin-wide trapping efficiency is established for new reservoirs. Given full implementation of the NRLP, we forecast reductions in annual suspended sediment transport to deltas of 4085% (Mahanadi), 7199% (Godavari) and 6097% (Krishna) due to profound reservoir trapping and peak streamflow reductions. The Ganga before its confluence with the Brahmaputra is projected to experience a 3975% reduction in annual suspended load. The Brahmaputra before its confluence with the Ganga is projected to experience a 925% reduction in suspended load, despite losing only 6% of its annual water flow. We calculate a projected corresponding aggradation decrease for the Ganga-Brahmaputra delta from 3.6 to 2.5 mm y1, which is a large enough change to drive relative sea-level rise at the delta front. At the remaining four deltas, the NRLP will exacerbate current sediment starvation. We reconstruct the annual water transfer volume proposed for the NRLP to be 245 km3 y1, higher than previous estimates due to the inclusion of along-canal usage. If completed, the NRLP will transform watershed boundaries, with more than half of the land in India contributing a portion of its runoff to a new mouth. These impacts may have profound environmental and public health implications, particularly in the context of future climate change.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/HYP.14110", "year": 2021, "title": "Long\u2010term hydrological, biogeochemical, and climatological data from Walker Branch Watershed, East Tennessee, USA", "abstract": "In 1967, the original Walker Branch Watershed (WBW) project was established to study elemental cycling and mass balances in a relatively unimpacted watershed. Over the next 50+ years, findings from additional experimental studies and long-term observations on WBW advanced understanding of catchment hydrology, biogeochemistry, and ecology and established WBW as a seminal site for catchment science. The 97.5-ha WBW is located in East Tennessee, USA, on the U.S. Department of Energy's Oak Ridge Reservation. Vegetation on the watershed is characteristic of an eastern deciduous, second-growth forest. The watershed is divided into two subcatchments: the West Fork (38.4 ha) and the East Fork (59.1 ha). Headwater streams draining these subcatchments are fed by multiple springs, and thus flow is perennial. Stream water is high in base cations due to weathering of dolomite bedrock and nutrient concentrations are low. Long-term observations of climate, hydrology, and biogeochemistry include daily (1969-2014) and 15-min (1994-2014) stream discharge and annual runoff (1969-2014); hourly, daily, and annual rainfall (1969-2012); daily climate and soil temperature (1993-2010); and weekly stream water chemistry (1989-2013). These long-term datasets are publicly available on the WBW website (https://walkerbranch.ornl.gov/long-term-data/). While collection of these data has ceased, related long-term measurements continue through the National Ecological Observatory Network (NEON), where WBW is the core terrestrial and aquatic site in the Appalachian and Cumberland Plateau region (NEON's Domain 7) of the United States. These long-term datasets have been and will continue to be important in evaluating the influence of climatic and environmental drivers on catchment processes.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1139/CJB-2021-0194", "year": 2021, "title": "Post-fire peatland vegetation recovery: a case study in open rich fens of the Canadian boreal forest", "abstract": " Fire plays a major role in the structuring and functioning of boreal ecosystems. As peatlands are important components of boreal forests, the impact of fire upon these wetter ecosystems is increasingly studied, but with the focus on treed peatlands and Sphagnum-dominated bogs so far. Important fires occurring more frequently in the past decade in southern Northwest Territories (Canada) provide the opportunity to assess early post-fire vegetation regeneration in open rich fens (one, two, and five years post-fire) and to better understand early recovery succession. We aimed to (i) evaluate whether and how open rich fens are affected by fire, and (ii) describe short-term vegetation regeneration for both bryophytes and vascular species. A shift was observed between pioneer bryophytes and brown mosses between the second and fifth year post-fire. Vascular plants, especially slow-growing species and the ones reproducing mainly by seeds, recovered partially. The first bryophyte species recovering were pioneer species adapted to colonize burned environments such as Marchantia polymorpha L. or Ceratodon purpureus (Hedw.) Brid. For vascular plant species, the ones previously present and able to regrow rapidly from unburned plant structures (base of tussocks, rhizomes, roots) were represented by species like Betula glandulosa Michx. or Carex aquatilis Wahlenb. The wetter conditions and lower fuel availability of fen depressional biotopes were important factors controlling the resistance and regeneration of species associated with them. ", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.149912", "year": 2022, "title": "Water environmental pressure assessment in agricultural systems in Central Asia based on an Integrated Excess Nitrogen Load Model", "abstract": "Agricultural runoff is the main source of water pollution in Central Asia. Excessive nitrogen (N) inputs from overuse of chemical fertilizers are threatening regional water resources. However, the scarcity of quantitative data and simplified empirical models limit the reliability of grey water footprint (GWF), particularly in undeveloped regions. In this study, we developed an Integrated Excess Nitrogen Load Model (IENLM) to calculate excess N load and evaluate its potential water environmental pressure in Central Asia. The model optimized the biological N fixation and atmospheric N deposition modules by involving more environmental variables and human activities. Results showed that N fertilizer application contributed over 60% to total N input and was mainly responsible for 42.9% increase of total GWF from 101.5 to 145.0 billion m3 during 1992 - 2018. Water pollution level (WPL) increased from 0.55 in 1992 to 2.41 in 2018 and the pollution assimilation capacity of water systems has been fully consumed just by N load from agriculture since 2005. GWF intensity and grey water pollution efficiency types in all Central Asian countries have improved in recent years except for Turkmenistan. N fertilizer application and agricultural economy development were the main driving factors induced N pollution. Results were validated by riverine nitrate concentrations and the estimates from prior studies. In future, combining the N fertilizer reduction with other farm management practices were projected to effectively improve the WPL. The modeling framework is favorable for N pollution research in data-scarce regions and provides a scientific basis for decision-making for agriculture and water resource managements.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1029/2019JC015556", "year": 2019, "title": "Quantifying the effects of nutrient enrichment and freshwater mixing on coastal ocean acidification", "abstract": "The U.S. Northeast is vulnerable to ocean and coastal acidification because of low alkalinity freshwater discharge that naturally acidifies the region, and high anthropogenic nutrient loads that lead to eutrophication in many estuaries. This study describes a combined nutrient and carbonate chemistry monitoring program in five embayments of Buzzards Bay, Massachusetts to quantify the effects of nutrient loading and freshwater discharge on aragonite saturation state (\u03a9). Monitoring occurred monthly from June 2015 to September 2017 with higher frequency at two embayments (Quissett and West Falmouth Harbors) and across nitrogen loading and freshwater discharge gradients. The more eutrophic stations experienced seasonal aragonite undersaturation, and at one site, nearly every measurement collected was undersaturated. We present an analytical framework to decompose variability in aragonite \u03a9 into components driven by temperature, salinity, freshwater endmember mixing, and biogeochemical processes. We observed strong correlations between apparent oxygen utilization and the portion of aragonite \u03a9 variation that we attribute to biogeochemistry. The regression slopes were consistent with Redfield ratios of dissolved inorganic carbon and total alkalinity to dissolved oxygen. Total nitrogen and the contribution of biogeochemical processes to aragonite \u03a9 were highly correlated, and this relationship was used to estimate the likely effects of nitrogen loading improvements on aragonite \u03a9. Under nitrogen loading reduction scenarios, aragonite \u03a9 in the most eutrophic estuaries could be raised by nearly 0.6 units, potentially increasing several stations above the critical threshold of 1. This analysis provides a quantitative framework for incorporating ocean and coastal acidification impacts into regulatory and management discussions.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.JENVMAN.2021.112838", "year": 2021, "title": "Quantifying the social benefits and costs of reducing phosphorus", "abstract": "Excess phosphorus loading to waterbodies has led to increasing frequency and severity of harmful algal blooms, negatively impacting economic activity and human health. While interventions to improve water quality can create large societal benefits, these investments are costly and the value of benefits is often unknown. Understanding the social and economic impacts of reduced phosphorus loading is critical for developing effective land use policies and for generating public and political support for these initiatives. Here, we quantify the social benefits and costs of improving water quality in Lake Champlain under a range of phosphorus reduction and climate change scenarios between 2016 and 2050. We use statistical models to link water quality outputs from an established integrated assessment model with three categories of benefits: tourism expenditures, property sales, and avoided human health impacts. We estimate the costs of reducing phosphorus loading using data reported by the State of Vermont. We find that under the most aggressive phosphorus reduction scenario, the total benefits of improved water quality are $55 to $60 million between 2016 and 2050. Over this 35 year time horizon, the combined benefits do not outweigh the costs under any scenario. If the time horizon is extended to 2100 or beyond, however, the benefits may exceed the costs if the applied discount rate is less than 3%. Importantly, we almost certainly underestimate the value of clean water, due to the omission of other types of benefits. Despite this uncertainty, our study provides a tractable framework for disentangling the complex relationships between water quality and human well-being, and illuminates the value of reductions in phosphorus loading to society.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.154454", "year": 2022, "title": "The interaction of physical structure and nutrient loading drives ecosystem change in a large tropical lake over 40 years", "abstract": "Many lakes across the world are entering novel states and experiencing altered biogeochemical cycling due to local anthropogenic stressors. In the tropics, understanding the drivers of these changes can be difficult due to a lack of documented historic conditions or an absence of continuous monitoring that can distinguish between intra- and inter-annual variation. Over the last forty years (19802020), Lake Yojoa (Honduras) has experienced increased watershed development as well as the introduction of a large net-pen Tilapia farm, resulting in a dramatic reduction in seasonal water clarity, increased trophic state and altered nutrient dynamics, shifting Lake Yojoa from an oligotrophic (low productivity) to mesotrophic (moderate productivity) ecosystem. To assess the changes that have occurred in Lake Yojoa as well as putative drivers for those changes, we compared Secchi depth (water clarity), dissolved inorganic nitrogen (DIN), and total phosphorus (TP) concentrations at continuous semi-monthly intervals for the three years between 1979 and 1983 and again at continuous 16-day intervals for 20182020. Between those two periods we observed the loss of a clear water phase that previously occurred in the months when the water column was fully mixed. Seasonal peaks in DIN coincident with mixing suggest that an enhanced accumulation of ammonium in the hypolimnion (the bottom layer of a stratified lake) during stratification, and release to the epilimnion (the top layer of a stratified lake) with mixing maintains high algal abundance and subsequently low Secchi depth during what was previously the clear water phase. This interaction of nutrient loading and Lake Yojoa's monomictic stratification regime illustrates a key phenomenon in how physical water column structure and nutrients interact in tropical monomictic lakes. This work highlights the need to consider nutrient dynamics of warm anoxic hypolimnions, not just surface water nutrient concentrations, to understand environmental change in these societally important but understudied ecosystems.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.3390/RS13122356", "year": 2021, "title": "Multiple Data Products Reveal Long-Term Variation Characteristics of Terrestrial Water Storage and Its Dominant Factors in Data-Scarce Alpine Regions", "abstract": "As the Water Tower of Asia and The Third Pole of the world, the QinghaiTibet Plateau (QTP) shows great sensitivity to global climate change, and the change in its terrestrial water storage has become a focus of attention globally. Differences in multi-source data and different calculation methods have caused great uncertainty in the accurate estimation of terrestrial water storage. In this study, the Yarlung Zangbo River Basin (YZRB), located in the southeast of the QTP, was selected as the study area, with the aim of investigating the spatio-temporal variation characteristics of terrestrial water storage change (TWSC). Gravity Recovery and Climate Experiment (GRACE) data from 2003 to 2017, combined with the fifth-generation reanalysis product of the European Centre for Medium-Range Weather Forecasts (ERA5) data and Global Land Data Assimilation System (GLDAS) data, were adopted for the performance evaluation of TWSC estimation. Based on ERA5 and GLDAS, the terrestrial water balance method (PER) and the summation method (SS) were used to estimate terrestrial water storage, obtaining four sets of TWSC, which were compared with TWSC derived from GRACE. The results show that the TWSC estimated by the SS method based on GLDAS is most consistent with the results of GRACE. The time-lag effect was identified in the TWSC estimated by the PER method based on ERA5 and GLDAS, respectively, with 2-month and 3-month lags. Therefore, based on the GLDAS, the SS method was used to further explore the long-term temporal and spatial evolution of TWSC in the YZRB. During the period of 19482017, TWSC showed a significantly increasing trend; however, an abrupt change in TWSC was detected around 2002. That is, TWSC showed a significantly increasing trend before 2002 (slope = 0.0236 mm/month, p < 0.01) but a significantly decreasing trend (slope = 0.397 mm/month, p < 0.01) after 2002. Additional attribution analysis on the abrupt change in TWSC before and after 2002 was conducted, indicating that, compared with the snow water equivalent, the soil moisture dominated the long-term variation of TWSC. In terms of spatial distribution, TWSC showed a large spatial heterogeneity, mainly in the middle reaches with a high intensity of human activities and the Parlung Zangbo River Basin, distributed with great glaciers. The results obtained in this study can provide reliable data support and technical means for exploring the spatio-temporal evolution mechanism of terrestrial water storage in data-scarce alpine regions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2020GL088543", "year": 2020, "title": "Global Characterization of Inland Water Reservoirs Using ICESat-2", "abstract": "Accurate, transparent knowledge of global reservoir levels is a prerequisite for effective management of water resources. However, no complete database exists because gauge data are not globally available and the current generation of satellite radar altimeters resolves only the world's largest reservoirs. Here, we investigate water level changes in global reservoirs using ICESat-2, National Aeronautics and Space Administration (NASA)'s new satellite laser altimetry mission. In just the first 12 months of the mission, we find that ICESat-2 accurately (\u00b114.1 cm) retrieved water level changes for 3,712 global reservoirs having surface areas ranging from <1 to >10,000 km2. From this new global data set, we identify distinct regional patterns in reservoir level change that can be attributed to both water availability and management strategy. Our findings demonstrate that ICESat-2 will form a crucial component of any global reservoir level inventory and enable new insight into how reservoir management responds to climatic variability and increasing human demand.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41561-019-0299-5", "year": 2019, "title": "Negligible cycling of terrestrial carbon in many lakes of the arid circumpolar landscape", "abstract": "High-latitude environments store nearly half of the planets below-ground organic carbon (OC), mostly in perennially frozen permafrost soils. Climatic changes drive increased export of terrestrial OC into many aquatic networks, yet the role that circumpolar lakes play in mineralizing this carbon is unclear. Here we directly evaluate ecosystem-scale OC cycling for lakes of interior Alaska. This arid, low-relief lake landscape is representative of over a quarter of total northern circumpolar lake area, but is greatly under-represented in current studies. Contrary to projections based on work in other regions, the studied lakes had a negligible role in mineralizing terrestrial carbon; they received little OC from ancient permafrost soils, and had small net contribution to the watershed carbon balance. Instead, most lakes recycled large quantities of internally derived carbon fixed from atmospheric CO2, underscoring their importance as critical sites for material and energy provision to regional food webs. Our findings deviate from the prevailing paradigm that northern lakes are hotspots of terrestrial OC processing. The shallow and hydrologically disconnected nature of lakes in many arid circumpolar landscapes isolates them from terrestrial carbon processing under current climatic conditions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.MARPOLBUL.2016.12.024", "year": 2017, "title": "Analysis of bloom conditions in fall 2013 in the Strait of Hormuz using satellite observations and model simulations", "abstract": "In this study an algal bloom event in fall 2013 in the Strait of Hormuz was thoroughly investigated using satellite remote sensing and hydrodynamic modeling. The motivation of this study is to deduce ambient conditions prior to and during the bloom outbreak and understand its trigger. Bloom tracking was achieved by sequential MODIS imagery and numerical simulations. Satellite observations showed that the bloom was initiated in late October 2013 and dissipated in early June 2014. Trajectories of bloom patches were simulated using a Lagrangian transport model. Model-based predictions of bloom patches' trajectories were in good agreement with satellite observations with a probability of detection (POD) reaching 0.85. Analysis of ancillary data, including sea surface temperature, ocean circulation, and wind, indicated that the bloom was likely caused by upwelling conditions in the Strait of Hormuz. Combined with numerical models, satellite observations provide an essential tool for investigating bloom conditions.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.2903/SP.EFSA.2019.EN-1629", "year": 2019, "title": "ENET wild modelling of wild boar distribution and abundance: initial model output based on hunting data and update of occurrence\u2010based models", "abstract": "After presenting preliminary models to estimate the habitat suitability for wild boar in MSs and neighbouring countries as a proxy for its relative abundance (i.e. the relative representation of a species in a particular ecosystem, a kind of proxy of the density) the ENETWILD consortium has developed further models for the estimation of wild boar abundance across this extent based on hunting yields (HY). This report therefore presents: i) updated maps of habitat suitability at 10x10 km resolution based on newly available data of wild boar occurrence together with new analysis to test the feasibility of performing such analysis at higher resolution (2x2 km); and, ii) a new model for predicting wild boar relative abundance, also at 10x10 km resolution, using hunting yields. The results of the occurrence model show that more occurrence data are required for specific locations in Eastern Europe in order to ensure robust model prediction of habitat suitability and consequently wild boar distribution. We used the hunting yields model to identify the environmental drivers of species abundance at European scale and fitted separate models for three regions (Southern, Western and Eastern Europe) to predict the distribution of wild boar at 10x10 km resolution. Our initial results highlighted some methodological issues relating to the statistical downscaling that should be taken into account to improve the reliability of the predictions. Whilst the spatial pattern in some areas was similar when comparing the predictions from both the occurrence and abundance models, in other regions there were marked discrepancies. To improve the models it is recommended to i) collect more occurrence data in the NorthEastern region of Europe, in particular on survey effort; ii) combine regional and local hunting records to validate hunting yield predictions to higher spatial resolutions; and, iii) incorporate new environmental variables, especially those closely associated with wild boar abundance and distribution.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.AGRFORMET.2020.108217", "year": 2020, "title": "Cross-scale evaluation of dynamic crop growth in WRF and Noah-MP-Crop", "abstract": "Accurately representing croplands in climate models is important for simulating water and energy fluxes between the land and atmosphere, as well as evaluating the impacts of climate change on agriculture. The recent integration of dynamic crop growth in the Noah land surface model with multiparameterization (Noah-MP-Crop) has the potential to substantially advance Earth system modeling and is included in the latest release of the Weather Research and Forecasting (WRF) regional climate model. The addition of dynamic crop growth to WRF provides a unique opportunity to simultaneously evaluate biases associated with a crop model coupled to a regional climate model and address outstanding questions regarding the role of agroecosystems in modulating regional climate. Here, we analyze dynamic crop growth in WRF across three simulated spatial scales (25km, 5km, and 1km) for growing seasons with precipitation above (2010), below (2012), and approximately equal (2015) to the seasonal average. Including dynamic crop growth in WRF significantly reduces biases in simulated leaf area index over croplands in the central U.S. relative to observations. However, there is no substantial difference in calculated daily evapotranspiration, average growing season temperature, or total growing season precipitation between WRF simulations with dynamic crops (WRF-Crop) compared to the dynamic vegetation module without crops (WRF-DV). Simulated corn (soy) mean absolute error (MAE), as a percentage of observed annual average yield, ranges from 24.7% -101% (28.1% - 109%) depending on year and spatial resolution, with the most significant biases in highly irrigated counties. Forcing Noah-MP-Crop with observed climate substantially reduces the range of corn (soy) yield MAE to 9.5% - 55.1% (15.0% - 37.5). Increased model resolution consistently leads to lower corn and soy yield estimates within WRF-Crop.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1111/DDI.12580", "year": 2017, "title": "Tiger abundance and gene flow in Central India are driven by disparate combinations of topography and land cover", "abstract": "AimEffective conservation of the endangered tiger depends upon reliable knowledge of factors driving genetic differentiation and population connectivity. Connectivity models frequently use resistance surfaces not optimized with actual movement or genetic data which limits reliability. Our aim is to use empirical data on genetic diversity of tiger populations to optimize landscape resistance to gene flow and identify factors that predict local population abundance across Central India.LocationThe study area covers 697,000 km2 across Madhya Pradesh and parts of Rajasthan, Jharkhand and Maharashtra.MethodsWe used genetic data of 309 tigers and restricted multivariate optimization of correlation between landscape variables and genetic distance in a reciprocal causal modelling framework to parameterize a resistance surface for gene flow. We further evaluated the association between effective population size and landscape connectivity using all\u2011subsets logistic regression with model averaging based on AICc.ResultsGene flow is primarily related to topographic roughness and slope position and secondarily to human footprint and land cover. It is much higher in areas of rough topography and ridge tops and is facilitated by forest cover in areas with low human footprint. In contrast, effective population size in protected areas is primarily driven by extent of protected areas and surrounding forest cover, and is not significantly related to resistant kernel connectivity value.Main ConclusionsThis is the first study to use a rigorous multivariate optimization approach to identify factors which limit gene flow of tigers. Tiger movement is highly affected by landscape features, and dispersing tigers move through rough terrain along forested ridges, avoiding non\u2011forest areas with high human footprint, while local tiger population density is driven primarily by the extent of protected forested habitat. These results have important implications for tiger conservation and can be used to develop empirically supported prioritization of core areas and corridors.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.FCR.2020.107825", "year": 2020, "title": "Assessing approaches for stratifying producer fields based on biophysical attributes for regional yield-gap analysis", "abstract": "Large databases containing producer field-level yield and management records can be used to identify causes of yield gaps. A relevant question is how to account for the diverse biophysical background (i.e., climate and soil) across fields and years, which can confound the effect of a given management practice on yield. Here we evaluated two approaches to group producer fields based on biophysical attributes: (i) a technology extrapolation domain spatial framework (TEDs) that delineates regions with similar (long-term average) annual weather and soil water storage capacity and (ii) clusters based on field-specific soil properties and weather during each crop phase in each year. As a case study, we used yield and management data collected from 3462 rainfed fields sown with soybean across the North Central US (NC-US) during four growing seasons (20142017). Following the TED approach, fields were grouped into 18 TEDs based on the TED that corresponded to the geographic location of each field. In the cluster approach, fields were grouped into clusters based on similarity of in-season weather and soil. To evaluate how the number of clusters would affect the results, fields were grouped separately into 5, 10, 18, and 30 clusters. The two stratification approaches (TEDs and clusters) were compared on their ability to explain the observed yield variation and yield response to key management factors (sowing date and foliar fungicide and/or insecticide). Lack of stratification of producer fields based on their biophysical background ignored management by environment (M E) interactions, leading to spurious relationships and results that are not relevant at local level. In the case of the cluster approach, a fine stratification (18 and 30 clusters) explained a larger portion of the yield variance compared with a coarse stratification (5 and 10 clusters). However, for our case study in the NC-US region, we did not find strong evidence that the data-rich clustering approach outperformed the TEDs on the ability to explain yield variation and identify M E interactions. Only the stratification into 30 clusters exhibited a small improved ability at explaining yield variation compared with the TEDs. However, the use of the clustering approach had important trade-offs, including large amount of data requirements and difficulties to scale results to different regions and over time. The choice of the stratification method should be based on objectives, data availability, and expected variation in yield due to erratic weather across regions and years.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1038/S41893-020-0483-Z", "year": 2020, "title": "Water scarcity and fish imperilment driven by beef production", "abstract": "Human consumption of freshwater is now approaching or surpassing the rate at which water sources are being naturally replenished in many regions, creating water shortage risks for people and ecosystems. Here we assess the impact of human water uses and their connection to water scarcity and ecological damage across the United States, identify primary causes of river dewatering and explore ways to ameliorate them. We find irrigation of cattle-feed crops to be the greatest consumer of river water in the western United States, implicating beef and dairy consumption as the leading driver of water shortages and fish imperilment in the region. We assess opportunities for alleviating water scarcity by reducing cattle-feed production, finding that temporary, rotational fallowing of irrigated feed crops can markedly reduce water shortage risks and improve ecological sustainability. Long-term water security and river ecosystem health will ultimately require Americans to consume less beef that depends on irrigated feed crops.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1088/1748-9326/AC20F4", "year": 2021, "title": "A review of global gridded cropping system data products", "abstract": "Abstract\r\n Agricultural monitoring, seasonal crop forecasting and climate change adaptation planning all require identifying where, when, how and which crops are grown. Global gridded cropping system data products offer useful information for these applications. However, not only the main sources of information (satellites, censuses, surveys and models) but also the spatial and temporal resolutions of these data products are quite distant from each other because of different user requirements. This is a barrier to strengthening collaborations among the research communities working to increase the capacity of societies to manage climate risks for global food systems, from extreme weather disasters to climate change. A first step is to improve cropping system data products so they can be used more seamlessly across various applications than they are currently. Toward this goal, this article reviews global gridded data products of crop variables (area, yield, cropping intensity, etc) using systematic literature survey, identifies their current limitations, and suggests directions for future research. We found that cropland or crop type mapping and yield or production estimation/prediction together accounted for half of the research objectives of the reviewed studies. Satellite-based data products are dominant at the finer resolution in space and time (<10 km and daily to annual), while model-based data products are found at the coarser resolutions (>55 km and decadal). Census-based data products are seen at intermediate resolutions (1055 km and annual to decadal). The suggested directions for future research include the hybridization of multiple sources of information, improvements to temporal coverage and resolution, the enrichment of management variables, the exploration of new sources of information, and comprehensiveness within a single data product.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGSY.2019.04.008", "year": 2019, "title": "A systems-level yield gap assessment of maize-soybean rotation under high-and low-management inputs in the Western US Corn Belt using APSIM", "abstract": "Quantifying yield gaps (potential minus actual yield) and identifying management practices to close those gaps is critical for sustaining high-yielding production systems. The objectives of this study were to: 1) calibrate and validate the APSIM maize and soybean models using local field experimental data and 2) use the calibrated model to estimate and explain yield gaps in the long term as a function of management (high- vs low-input) and weather conditions (wet-warm, wet-cold, dry-warm and dry-cold years) in the western US Corn Belt. The model was calibrated and validated using in-season crop growth data from six maize-soybean rotations obtained in 2014 and 2015 in Kansas, US. Experimental data included two management systems: 1) Common Practices (CP, low-input), wide row spacing, lower seeding rate, and lack of nutrient applications (except N in maize), and 2) Intensified Practices (IP, high-input), narrow rows, high seeding rate, and balanced nutrition. Results indicated that APSIM simulated in-season crop above ground mass and nitrogen (N) dynamics as well yields with a modeling efficiency of 0.75 to 0.92 and a relative root mean square error of 18 to 31%. The simulated maize yield gap across all years was 4.2 and 2.5 Mg ha1 for low- and high-input, respectively. Similarly, the soybean yield gap was 2.5 and 0.8 Mg ha1. Simulation results indicated that the high-input management system had greater yield stability across all weather years. In warm-dry years, yield gaps were larger for both crops and water scenarios. Irrigation reduced yield variation in maize more than in soybean, relative to the rainfed scenario. Besides irrigation, model analysis indicated that N fertilization for maize and narrow rows for soybean were the main factors contributing to yield gains. This study provides a systems level yield gap assessment of maize and soybean cropping system in Western US Corn Belt that can initiate dialogue (both experimental and modeling activities) on finding and applying best management systems to close current yield gaps.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.GLOENVCHA.2019.101982", "year": 2020, "title": "Rural-urban connectivity and agricultural land management across the Global South", "abstract": "Research on how urbanization affects rural agriculture has typically focused on loss of farmland due to urban expansion. However, more distal pathways that could link urbanization to rural agriculture, including enhanced connectivity through rural-urban migration and market access, remain poorly understood. Here, we assess whether greater rural-urban connectivity is associated with changes in agricultural land management across the Global South. Such associations are complex, and thus difficult to measure at this scale. We therefore take a two-step approach to investigate these relationships. First, using a multivariate clustering approach, we define a series of rural-urban connectivity typologies from existing spatial data on land use, demographics, rural market access, and rural population change (as a proxy for outmigration). We examine the variation in key agricultural outcome variables (mean cereal crop yields, % of attainable yields met, and cropping frequency) within the typologies, which shows that greater overall connectivity (market access and population change) is associated with higher cereal yields, yield attainment, and cropping frequency. Second, building on these clustering results, we develop hypotheses about the relationship between rural-urban connectivity and agricultural land use intensity. We then use propensity score matching to test these hypotheses by comparing locations with similar sociodemographic and land use characteristics. When controlling for gross domestic product (GDP) per capita, agricultural land, and population density, rural locations with relatively high market access, negative population change, and greater built-up area have significantly higher mean nitrogen application rates, irrigated areas, and cereal yields across the Global South. Results vary by region, but greater rural-urban connectivity and urban extents are generally associated with higher overall agricultural inputs and yields, particularly in Asia. However, we find little support for a relationship between connectivity and either % attainable yields met or field size. Our findings stress the need to better understand the mechanisms that link urbanization processes and agricultural management at different spatiotemporal scales.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S11119-021-09850-7", "year": 2021, "title": "Identifying crop yield gaps with site-and season-specific data-driven models of yield potential", "abstract": "There is considerable interest and value in identifying the gap between crop yields that have actually been achieved, and yields that could have potentially been achieved. A suite of methods currently exist to estimate the yield potential of a crop, but there are no approaches that predict the site- and season-specific yield potential using datasets that are readily available and easily accessible for farmers. The aim of this study was to fill this need and develop a novel approach to identify crop yield gaps through site- and season-specific models of crop yield potential. The study focused on cotton lint yield, with data from 14 different seasons and 68 different fields from a collection of large, irrigated cotton farms in eastern Australia. This abundance of yield data was then joined with other spatial and temporal datasets that describe yield, such as rainfall, temperature, soil, and management. A quantile random forest machine learning model was then used to model yield at 30 m resolution, where the 95th percentile predictions were treated as the yield potential. The yield gaps at a 30 m resolution were then estimated for all seasons and sites. The results were compared to a more traditional historical maximum yield approach, where no data modelling and only empirical yield data was used to estimate the yield potential. This revealed that there was a general agreement between the two approaches, although the quantile machine learning approach is both site- and season-specific, not just site-specific. Overall, there is a great need for alternative approaches to estimate yield potential and yield gaps, as the approaches currently available possess many limitations. The approach developed in this study has the potential for wide-spread adoption in broadacre cropping systems, and if the causes of yield gaps are identified, could lead to the implementation of management strategies to close them.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGWAT.2022.107712", "year": 2022, "title": "Remote sensing assessment of available green water to increase crop production in seasonal floodplain wetlands of sub-Saharan Africa", "abstract": "Producing more food for a growing population requires sustainable crop intensification and diversification, particularly in high-potential areas such as the seasonal floodplain wetlands of sub-Saharan Africa (SSA). With emerging water shortages and concerns for conserving these multi-functional wetlands, a further expansion of the cropland area must be avoided as it would entail increased use of blue water for irrigation and infringe on valuable protected areas. We advocate an efficient use of the prevailing green water on the existing cropland areas, where small-scale farmers grow a single crop of rainfed lowland rice during the wet season. However, soil moisture at the onset of the rains (pre-rice niche) and residual soil moisture after rice harvest (post-rice niche) may suffice to cultivate short-cycled crops. We developed a methodological approach to analyze the potential for green water cultivation in the pre- and post-rice niches in the Kilombero Valley Floodplain in Tanzania, as a representative case for seasonal floodplain wetlands in SSA. The three-step approach used open-access remote sensing datasets to: (i) extract cropland areas; (ii) analyze soil moisture conditions using evaporative stress indices to identify the pre- and post-rice niches; and (iii) quantify the green water availability in the identified niches through actual evapotranspiration (AET). We identified distinct patterns of green water being available both before and after the rice-growing period. Based on the analyses of evaporative stress indices, the pre-rice niche tends to be longer (~70 days with average AET of 2040 mm/10-day) but also more variable (inter-annual variability >30%) than the post-rice niche (~65 days with average AET of 1030 mm/10-day, inter-annual variability <15%). These findings show the large potential for cultivating short-cycled crops beyond the rice-growing period, such as green manure, vegetables, maize, and forage legumes, by shifting a portion of the nonproductive AET flows (i.e., soil evaporation) to productive flows in form of crop transpiration. A cropland area of 1452 to 1637 km2 (5360% of the total cropland area identified of 2730 km2) could be cultivated using available green water in the dry season, which shows the significance of such change for food security, livelihoods, and resilience of the agricultural community in Kilombero. A wider application of the developed approach in this study can help identifying opportunities and guiding interventions and investments towards establishing sustainable intensification and diversification practices in floodplain wetlands in SSA.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.JHYDROL.2020.124905", "year": 2020, "title": "A review of remote sensing applications in agriculture for food", "abstract": "The global population is expected to reach 9.8 billion by 2050. There is an exponential growth of food production to meet the needs of the growing population. However, the limited land and water resources, climate change, and an increase in extreme events likely to pose a significant threat for achieving the sustainable agriculture goal. Given these challenges, food security is included in the United Nations' Sustainable Development Goals (SDGs). Since the advent of Sputnik, followed by the Explorer missions, satellite remote sensing is assisting us in collecting the data at global scales. In this work, we review how satellite remote sensing information is utilized to assess and manage agriculture, an important component of ecohydrology. Overall, three critical aspects of agriculture are considered: (a) crop growth and yield through empirical models, physics-based models, and data assimilation in crop models, (b) applications pertaining to irrigation, which include mapping irrigation areas and quantification of irrigation, and (c) crop losses due to pests, diseases, crop lodging, and weeds. The emphasis is on satellite sensors in optical, thermal, microwave, and fluorescence frequencies. We conclude the review with an outlook of challenges and recommendations. This paper is the first of a two-part review series. The second part reviews the role of satellite remote sensing in water security, wherein we discuss the aspects of water quality and quantity along with extremes (floods and droughts).", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.14288/1.0416294", "year": 2022, "title": "Human conflict and coexistence with mountain goats in a protected alpine landscape", "abstract": "Of the North American ungulates, mountain goats (Oreamnos americanus) are among the most sensitive to anthropogenic disturbance. In British Columbia (BC), there is a particularly vulnerable population of mountain goats in Cathedral Provincial Park (CPP). The herd in CPP is isolat", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/RS14133017", "year": 2022, "title": "Temporal Variation and Component Allocation Characteristics of Geometric and Physical Parameters of Maize Canopy for the Entire Growing Season", "abstract": "The accurate monitoring of crop parameters is important for crop yield prediction and canopy parameter inversion from remote sensing. Process-based and semi-empirical crop models are the main approaches to modeling the temporal changes in crop parameters. However, the former requires too many input parameters and the latter has the problem of poor portability. In this study, new semi-empirical geometric and physical parameters of the maize canopy model (GPMCM) crop model adapted to northeast China were proposed based on a time-series field datasets collected from 11 sites in the Nongan and Changling Counties of Jilin Province, China, during DOY (day of year) 163 to DOY 278 in 2021. The allocation characteristics of and correlations between each maize canopy parameter were investigated for the whole growing season using the 22 algorithms of crop parameters, and the following conclusions were obtained. (1) The high correlation coefficient (R mean = 0.79) of LAI with other canopy parameters indicated that it was a good indicator for predicting other parameters. (2) Better performance was achieved by the regression method based on the two-stage simulation. The root-mean-squared error (RMSE) of geometric parameters including maize height, stem long radius, and short radius were 12.91 cm, 0.74 mm, and 0.73 mm, respectively, and the RMSE of the physical parameters including the FAGB, AGB, VWC, and RWC of the stems and leaves, ranged from 0.05 kg/m2 to 4.24 kg/m2 (2.0% to 12.9% for mean absolute percentage error (MAPE)). (3) The extension of the field-scale GPMCM to the 500 m MODIS-scale still provided a good accuracy (MAPE: 11% to 18.5%) and confirmed the feasibility of the large-scale application of the GPMCM. The proposed CPMCM can predict the temporal dynamics of maize geometric and physical parameters, and it is helpful to establish the forward and reverse models of remote sensing and improve the inversion accuracy of crop parameters.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S00704-021-03799-3", "year": 2021, "title": "Towards crop yield estimation at a finer spatial resolution using machine learning methods over agricultural regions", "abstract": "Reliable yield estimation is crucial for food security and agricultural production especially in the intensively agricultural region. This study constructed a gridded yield estimation framework by driving machine learning models with remote sensing vegetation index and meteorological forcing. Among eight machine learning methods, support vector machine (SVM), k-nearest neighbor regression (KNN), and Gaussian process regression (GPR) models outperformed the others. Precipitation, temperature, and the fraction of photosynthetically active radiation are key factors for yield estimation. The yield estimation at county level and regional level were further conducted to explore the scale effect (estimation accuracy varies with spatial resolution). Different scales hold diverse spatial variability information. Finer scales that are more representative of spatial variability generally result in the better accuracy. This study demonstrates that a more accurate yield estimation can be achieved at a finer grid level, thus providing guidelines for agricultural planting structure.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/AGRONOMY10060809", "year": 2020, "title": "Local-scale cereal yield forecasting in Italy: Lessons from different statistical models and spatial aggregations", "abstract": "Statistical, data-driven methods are considered good alternatives to process-based models for the sub-national monitoring of cereal crop yields, since they can flexibly handle large datasets and can be calibrated simultaneously to different areas. Here, we assess the influence of several characteristics on the ability of these methods to forecast cereal yields at the local scale. We look at two diverse agro-climatic Italian regions and analyze the most relevant types of cereal crops produced (wheat, barley, maize and rice). Models of different complexity levels are built for all species by considering six meteorological and remote sensing indicators as candidate predictive variables. Yield data at three different spatial aggregation scales were retrieved from a comprehensive, farm-level dataset over the period 20012015. Overall, our results suggest the better predictability of summer crops compared to winter crops, irrespective of the model considered, reflecting a more intricate relationship among winter cereals, their physiology and weather patterns. At higher spatial resolutions, more sophisticated modelling techniques resting on feature selection from multiple indicators outperformed more parsimonious linear models. These gains, however, vanished as data were further aggregated spatially, with the predictive ability of all competing models converging at the agricultural district and province levels. Feature-selection models tended to elicit more satellite-based than meteorological indicators, with a preference for temperature indicators in summer crops, whereas variables describing the water content of the soil/plant were more often selected in winter crops. The selected features were, in general, equally distributed along the plant growing cycle.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S12517-020-06085-0", "year": 2020, "title": "Determining paddy field spatiotemporal distribution and temperature influence using remote sensing in Songnen Plain, Northeastern China", "abstract": "This study investigates changes in the spatial distributions of paddy fields in the Songnen Plain (Chinas largest commodity grain-producing area) using the Satellite Pour lObservation de la TerreVegetation (SPOT VEGETATION) time series product data to simulate the phenological characteristics of paddy rice growth. According to the analysis, the characteristics of paddy fields are different from other vegetation cover around late May (15th 10-day). This difference can be used to improve accuracy in identifying paddy fields. Historical maps (19992013) are extracted successfully in this work. Based on the results, a trend map for changes in paddy field areas is generated using a 10-km grid. Based on the verification of paddy field extractions in 2019 using the Project for On-Board Autonomy-Vegetation (PROBA VEGETATION), the trend map is strongly indicative for predicting future spatial distribution changes of paddy fields. These results can be used to provide a reliable theoretical basis for environmental research related to the growth of paddy rice. This study also verifies that paddy rice cultivation is one of the main causes of rising temperatures in the study area.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1002/EAP.2368", "year": 2021, "title": "Nitrogen cycling in pastoral livestock systems in Sub\u2010Saharan Africa: knowns and unknowns", "abstract": "Pastoral systems are the dominant livestock production system in arid and semiarid regions of sub\u2011Saharan Africa (SSA). They are often the only form of agriculture that can be practiced due to unfavorable climate and soil fertility levels that prevent crop cultivation. Pastoralism can have negative impacts on the environment, including land degradation, greenhouse gas emissions and other gases to the atmosphere, soil erosion, water pollution and biodiversity loss. Here, we review the current knowledge on nitrogen (N) cycling, storage, and loss pathways, with an emphasis on identification of N emission hotspots. Our review reports a large uncertainty in the amount of N lost as ammonia from excreta and manure storage, as well as N losses via nitrate and DON leaching. We also found that another major N loss pathway (18%), soil N2 emissions, has not yet been measured. In order to summarize the available information, we use a virtual pastoral farm, with characteristics and management practices obtained from a real farm, Kapiti Research Station in Kenya. For outlining N flows at this virtual farm, we used published data, data from global studies, satellite imagery and geographic information system (GIS) tools. Our results show that N inputs in pastoral systems are dominated by atmospheric N deposition (\u223c80%), while inputs due to biological nitrogen fixation seems to play a smaller role. A major N loss pathway is nitrogen leaching (nitrate > DON) from pastures (33%). Cattle enclosures (bomas), where animals are kept during night, represent N emissions hotspots, representing 16% of the total N losses from the system. N losses via ammonia volatilization and N2O were four and three orders of magnitude higher from bomas than from the pasture, respectively. Based on our results, we further identify future research requirements and highlight the urgent need for experimental data collection to quantify nitrogen losses from manure in animal congregation areas. Such information is needed to improve our understanding on N cycling in pastoral systems in semiarid regions and to provide practical recommendations for managers that can help with decision\u2011making on management strategies in pastoral systems in semiarid savannas.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1002/WSB.728", "year": 2017, "title": "Energy development and hunter success for mule deer and pronghorn in Wyoming", "abstract": "Infrastructure associated with energy development influences hunter access and introduces disturbance activities to landscapes that can influence habitat selection and behavior of ungulates. Consequently, habitat loss and hunter access concerns must be addressed by wildlife managers as they consider management of populations of western big game species including mule deer (Odocoileus hemionus) and pronghorn (Antilocapra americana). We evaluated whether increased energy development, as quantified through change in well pad density, has affected hunter success of mule deer and pronghorn. Ungulates tend to avoid energy development; therefore, we also evaluated whether hunting statistics can be used to identify potential effects of energy development on mule deer and pronghorn. We included data from 22 of 39 mule deer and 34 of 46 pronghorn Herd Units across Wyoming, USA, from 1980 to 2012. On average, well pad densities across mule deer Herd Units increased from 0.01 km2 in 1980 to 0.06 km2 in 2012, and well pads in pronghorn Herd Units increased from 0.01 km2 to 0.12 km2 during the same period. Our results indicated that hunter success for mule deer in Wyoming was positively associated with hunter effort, whereas pronghorn hunter success was negatively associated with hunter effort. Hunter success for both species was unaffected by well pad density. We identified a change in mule deer and pronghorn harvest success associated with hunter numbers and effort; however, harvest statistics were not informative in identifying impacts from energy development on mule deer or pronghorn populations.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.RSE.2020.112174", "year": 2021, "title": "A million kernels of truth: Insights into scalable satellite maize yield mapping and yield gap analysis from an extensive ground dataset in the US Corn Belt", "abstract": "Crop yield maps estimated from satellite data increasingly are used to understand drivers of yield trends and variability, yet satellite-derived regional maps are rarely compared with location-specific yields due to the difficulty of acquiring sub-field ground truth data at scale. In commercial agricultural systems, combine harvesters with onboard yield monitors collect real-time yield data during harvest with high spatial resolution, generating a large ground dataset. Here, we leveraged a yield monitor dataset of over one million maize field observations across the United States Corn Belt from 2008 to 2018 to evaluate the Scalable Crop Yield Mapper (SCYM). SCYM uses region-specific crop model simulations and climate data to interpret vegetation indices from satellite observations, thus enabling efficient sub-field yield estimation across large regions and multiple years without reliance on ground data calibration. We used the ground dataset to compare alternative SCYM model implementations, define minimum required satellite observation criteria, and evaluate the sensitivity of satellite-based yield estimates to on-the-ground variation in management, soil, and annual weather. We found that smoothing annual time series data with harmonic regression increased 30 m pixel-level accuracy from r2 = 0.31 to 0.40 and reduced dependency on specific satellite observation timing, enabling robust yield estimation on 97% of annual maize area using only Landsat data. Agreement improved as the assessment was aggregated to field-level (r2 = 0.45) and county-level (r2 = 0.69) scales, demonstrating the need for fine-resolution ground truth data to better assess sub-field level accuracy in high resolution products. We found that SCYM and ground data showed a similar yield response to management and environmental variation, particularly capturing linear and nonlinear responses to sowing density, soil water holding capacity, and growing season precipitation. However, sensitivity to factors like soil quality and planting date was muted for SCYM estimates compared to ground-based yields. Random forest models were able to match SCYM performance when trained on at least 1000 ground observations, but performed poorly when tested on years and locations not represented in the training data. Our results demonstrate that satellite yield maps can provide much-needed information on multidecadal yield trends and inform yield gap analyses.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.01.172", "year": 2019, "title": "Climate drives variability and joint variability of global crop yields", "abstract": "In this study, long-term national-based yields of maize, rice, sorghum and soybean (MRSS) from 1961 to 2013 are decomposed using Robust Principal Component Analysis (RPCA). After removing outliers, the first three principal components (PC) of the persistent yield anomalies are scrutinized to assess their association with climate and to identify co-varying countries and crops. Sea surface temperature anomalies (SSTa), atmospheric and oceanic indices, air temperature anomalies (ATa) and Palmer Drought Severity Index (PDSI) are used to study the association between the PCs and climate. Results show that large-scale climate, especially El Nino-Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) are strongly correlated with crop yield variability. Extensive maize harvesting regions in Europe and North America, rice in South America, Oceania and east of Asia, sorghum in west and southeast of Asia, North America and Caribbean and soybean in North and South America, Oceania and south of Asia experienced the influence of local climate variability in this period. Sorghum yield variability across the globe exhibits significant correlations with many atmospheric and oceanic indices. Results indicate that not only do the same crops in many countries co-vary significantly, but different crops, in particular maize, in different PCs also co-vary with other crops. Identifying the association between climate and crop yield variability and recognizing similar and dissimilar countries in terms of yield fluctuations can be informative for the identified nations with regard to the periodic and predictable nature of many large-scale climatic patterns.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.EJA.2022.126718", "year": 2022, "title": "Efficiency of assimilating leaf area index into a soybean model to assess within-field yield variability", "abstract": "Methods for accurately estimating within-field yield are essential to improve site-specific crop management and resource use efficiencies, which would be a major step toward sustainable intensification of agricultural systems. We set out to assess the accuracy of within-field soybean yields predicted by two data assimilation methods and to assess these methods assimilation efficiency (AE). Yields were estimated by assimilating remotely sensed leaf area index (LAI) data from Sentinel-2 into a soybean crop growth model on a pixel basis. The LAI data was integrated into the model by Ensemble Kalman Filtering (EnKF) or by recalibrating with the Subplex algorithm (recalibration-based). An open-loop setting which only integrates information on the soil layers was used as a baseline scenario for quantifying the AE. We assessed both data assimilation techniques on eight fields (3067 pixels) in the Corn Belt region (Nebraska, Kansas and Kentucky) in the United States. The data set encompassed substantial variation in crop growth conditions: three growing seasons (2018, 2019 and 2020), rainfed and irrigated fields, and early and late planting dates. Ground truth yield acquired from combine monitors was used to validate the yield estimations. Agreement between predicted and observed yield at pixel level was two times higher for both data assimilation methods compared to the open-loop. The root mean square error (RMSE) was 476 kg.ha1 (RRMSE of 10 %) in the recalibration-based method and 573 kg.ha1 (RRMSE of 12 %) in the EnKF-based method. For both data assimilation methods, assimilating the LAI improved predictions for 68 % of the pixels. For a further 12 % of pixels, there was no accuracy improvement. For the remaining 20 %, AE was positive for one of the two assimilation methods. The high proportion of pixels with positive AE indicates the potential for overcoming the limitations in applying crop models at high spatial resolution by integrating a crop growth indicator. Assimilating an in-season indicator of crop growth (LAI) into a soybean model made it possible to adjust the simulation pathway, thereby greatly improving the accuracy of the yield estimations at the pixel level. This study elucidates the practical applications of data assimilation strategies for fine-scale within-field crop yield mapping.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ESSD-9-667-2017", "year": 2017, "title": "Global manure nitrogen production and application in cropland during 1860\u20132014: a 5 arcmin gridded global dataset for Earth system modeling", "abstract": "Abstract. Given the important role of nitrogen input from livestock systems in terrestrial nutrient cycles and the atmospheric chemical composition, it is vital to have a robust estimation of the magnitude and spatiotemporal variation in manure nitrogen production and its application to cropland across the globe. In this study, we used the dataset from the Global Livestock Impact Mapping System (GLIMS) in conjunction with country-specific annual livestock populations to reconstruct the manure nitrogen production during 18602014. The estimated manure nitrogen production increased from 21.4 Tg N yr1 in 1860 to 131.0 Tg N yr1 in 2014 with a significant annual increasing trend (0.7 Tg N yr1, p < 0.01). Changes in manure nitrogen production exhibited high spatial variability and concentrated in several hotspots (e.g., Western Europe, India, northeastern China, and southeastern Australia) across the globe over the study period. In the 1860s, the northern midlatitude region was the largest manure producer, accounting for 52 % of the global total, while low-latitude regions became the largest share ( 48 %) in the most recent 5 years (20102014). Among all the continents, Asia accounted for over one-fourth of the global manure production during 18602014. Cattle dominated the manure nitrogen production and contributed 44 % of the total manure nitrogen production in 2014, followed by goats, sheep, swine, and chickens. The manure nitrogen application to cropland accounts for less than one-fifth of the total manure nitrogen production over the study period. The 5 arcmin gridded global dataset of manure nitrogen production generated from this study could be used as an input for global or regional land surface and ecosystem models to evaluate the impacts of manure nitrogen on key biogeochemical processes and water quality. To ensure food security and environmental sustainability, it is necessary to implement proper manure management practices on cropland across the globe. Datasets are available at https://doi.org/10.1594/PANGAEA.871980 (Zhang et al., 2017).", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.GLOENVCHA.2021.102313", "year": 2021, "title": "Agroecological measures and circular economy strategies to ensure sufficient nitrogen for sustainable farming", "abstract": "Sustainable food systems face trade-offs between demands of low environmental pressures per unit area and requirements of increasing production. Organic farming has lower yields than conventional agriculture and requires the introduction of nitrogen (N) fixing legumes in crop rotations. Here we perform an integrated assessment of the feasibility of future food systems in terms of land and N availability and the potential for reducing greenhouse gas (GHG) emissions. Results show that switching to 100% organic farming without additional measures results in N deficiency. Dietary change towards a reduced share of animal products can aggravate N limitations, which can be overcome through the implementation of a combination of agroecological, circular economy and decarbonization strategies. These measures help to recycle and transfer N from grassland. A vegan diet from fully decarbonized conventional production performs similarly as the optimized organic scenario. Sustainable food systems hence require measures beyond the agricultural sector.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ESSD-13-3203-2021", "year": 2021, "title": "A historical reconstruction of cropland in China from 1900 to 2016", "abstract": "Abstract. A spatially explicit cropland distribution time-series dataset is the basis for the accurate assessment of biogeochemical processes in terrestrial ecosystems and their feedback to the climate system; however, this type of dataset is lacking in China. Existing cropland maps have a coarse resolution, are intermittently covered, or the data are inconsistent. We reconstructed a continuously covered cropland distribution dataset in China spanning from 1900 to 2016 by assimilating multiple data sources. In total, national cropland acreage expanded from 77.72 Mha in 1900 to a peak of 151.00 Mha in 1979, but it consistently decreased thereafter to 134.92 Mha in 2016. The cropland was primarily distributed in three historically cultivated plains in China: the Sichuan Plain, the Northern China Plain, and the Northeast China Plain. Cropland abandonment was approximately 43.12 Mha: it was mainly concentrated in the Northern China Plain and the Sichuan Plain and occurred during the 19902010 period. Cropland expansion was over 74.37 Mha: it was primarily found in the southeast, northern central, and northeast regions of China and occurred before 1950. In comparison, the national total and spatial distribution of cropland in the Food and Agriculture Organization (FAO) of the United Nations and the History Database of the Global Environment (HYDE) were distorted during the period from 1960 to 1980 due to the biased signal from the Chinese Agricultural Yearbook. We advocate that newly reconstructed cropland data, in which the bias has been corrected, should be used as the updated data for regional and global assessments, such as greenhouse gas emission accounting studies and food production simulations. The cropland dataset is available via an open-data repository (https://doi.org/10.6084/m9.figshare.13356680; Yu et al., 2020).", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.AGEE.2021.107585", "year": 2021, "title": "Marginal more than mesic sites benefit from groundnut diversification of", "abstract": "Sustainable Intensification (SI) interventions are urgently required, particularly those suited to resource poor farms in Africa. Legume crops have been promoted as a key ingredient for SI of rainfed grain production on smallholder farms, with variable results. There is a need to explore the extent to which legume diversification of maize production impacts stability, nutrition, and income. This is particularly so for marginal environments. On-farm experimentation was conducted in Central Malawi over two to seven years on 29 farm sites (120 year-site combinations). The farms were located within four areas that included lakeshore, dissected hills (two locations) and upland plain. Maize diversification included a long-duration legume pigeonpea and a medium duration legume groundnut, grown in rotation or intercropped with maize, and as a doubled-up legume rotation (DLR). To quantify the performance of systems under low, medium, and high yield environments, we used long-term average maize yield to categorize each farm site. All legume diversified systems supported stable grain production in the low yield environment, as shown by 37-41% coefficient of variation for yield, in comparison to 62% for sole maize. The groundnut systems consistently produced the highest grain yield, protein, stable yields, and economic returns, and this performance held up in marginal, low yield environments. In this multi-site, multi-year, on-farm replicated study, the performance of groundnut systems (GnRot and DLR) stood out for high protein (0.529 T ha-1 2 yr-1 and 0.615 T ha -1 2 yr-1, respectively over two years) versus unfertilized maize (0.169 T ha-1 2 yr-1). These two groundnut-based systems were produced with half-fertilizer rates compared to sole maize and were economically high performers. However, there was a barrier to adoption of GnRot and DLR in that improved groundnut seed was expensive (USD 157 ha-1 2 yr-1), this initial investment being beyond the means of many farmers, despite the cost largely offset by the generation of high income (USD 1636-1993 ha-1 2 yr-1). Long-term sustainability was assessed by monitoring soil organic carbon (SOC), which was found to be markedly influenced by soil texture (sites with SOC >1.5% had sand content <50%). Legume diversification effects on SOC were not discerned, possibly due to high sand content on the oldest trial sites. This study highlights the value of longitudinal data and including a wide range of soil texture sites in on-farm experimentation to identify overall legume diversification effects within maize systems.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1073/PNAS.1910719117", "year": 2020, "title": "Rainfall anomalies are a significant driver of cropland expansion", "abstract": "Significance\r\n Rainfall anomalies are known to have deleterious impacts on agricultural yields, but the resulting consequences on cropland expansion remain uncertain. We study the differential scale of these impacts around the world. We find that repeated dry anomalies increase cropland expansion specifically in developing countries, which are characteristically dominated by small-holder farming, implying that cropland is expanded to compensate for lower yields. Two tests corroborate the results. First, comparable reductions in forest cover due to repeated dry anomalies are found in the same regions where cropland expands. Second, in places where infrastructure buffers yields from rainfall anomalies, cropland expansion halts. Understanding the synchronous challenges facing agriculture and the environment will be critical to inform appropriate policy interventions.\r\n , \r\n Rainfall anomalies have long occupied center stage in policy discussions, and understanding their impacts on agricultural production has become more important as climate change intensifies. However, the global scale of rainfall-induced productivity shocks on changes in cropland is yet to be quantified. Here we identify how rainfall anomalies impact observed patterns of cropped areas at a global scale by leveraging locally determined unexpected variations in rainfall. Employing disaggregated panel data at the grid level, we find that repeated dry anomalies lead to an increase in cropland expansion in developing countries. No discernible effects are detected from repeated wet events. That these effects are confined to developing countries, which are often dominated by small-holder farmers, implies that they may be in response to reduced yields. The estimates suggest that overall, in developing countries, dry anomalies account for 9% of the rate of cropland expansion over the past two decades. We perform several tests to check for consistency and robustness of this relationship. First, using forest cover as an alternative measure, we find comparable reductions in forest cover in the same regions where cropland expands due to repeated dry anomalies. Second, we test the relationship in regions where yields are buffered from rainfall anomalies by irrigation infrastructure and find that the impact on cropland expansion is mitigated, providing further support for our results. Since cropland expansion is a significant driver of deforestation, these results have important implications for forest loss and environmental services.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1109/IGARSS39084.2020.9324027", "year": 2020, "title": "Crop yield estimation using multi-source satellite image series and deep learning", "abstract": "Timely monitoring of agricultural production and early yield predictions are essential for food security. Crop growth conditions and yield are related to climate variability and are impacted by extreme events. Remotely sensed time-series could be used to study the variability in crop growth and agricultural production. However, the choice of remotely sensed data and methods is still an issue, as different datasets have different spatiotemporal characteristics. Our primary goal was to test different algorithms and several remotely sensed time-series datasets for yield estimation in U.S. at county and field scale. For a county-level analysis, MODIS-based surface reflectance, Land Surface Temperature, and Evapotranspiration time series were used as input datasets. Field-level analysis was carried out using NASA's Harmonized Landsat Sentinel-2 (HLS) product. For this purpose, 3D convolutional neural network (CNN) and CNN followed by long-short term memory (LSTM) were used. For county-level analysis, the CNN-LSTM model had the highest accuracy, with a mean percentage error of 10.3% for maize and 9.6% for soybean. This model presented robust results for the year 2012, which is considered a drought year. In the case of field-level analysis, all models achieved accurate results with R2 exceeding 0.8 when data from mid growing season were used. The results highlight the potential of using satellite data for yield estimation at different management scales.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.15407/AGRISP4.02.003", "year": 2017, "title": "Long-term prediction of climate change impact on the productivity of grain crops in Ukraine using satellite data", "abstract": "Aim. To analyze and predict the climate change impact on the crop structure, yield and gross collections of grain crops in short-term (2025), mid-term (2050) and long-term perspective. Methods. Analysis of long-term series of climatic parameters based on satellite data, climatic modeling, statistical analysis of crop yield and gross collection of grain crops. Results. The positive effect of historical and current climate change on grain crop yields in Ukraine is demonstrated. It is predicted that the preservation of this pattern and the implementation of an integrated system of measures for adapting agroecosystems to warming will promote further increase in the grain crop yield and thus its gross collection. Conclusions. According to the analysis of satellite data and climatic models, further climate warming is predicted and its positive impact on grain crop productivity is forecasted. In case of developing and implementing the measures to adapt agroecosystems to climate change, the grain yield in Ukraine\nmay increase by 25 % in 2025 compared with the current period (2015) and by 2930 % in 2050; the gross collection of grain crops will reach 75.0 million tons (in 2025) and 79.080.0 million tons (in 2050). On condition of effi cient material and technical, scientifi c and informational support, further development of technical means, the reproduction of soil fertility and the improvement of irrigation technologies in the long-term perspective (by 2100), the gross grain collection may reach 9295 million tons.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1038/S43016-022-00543-6", "year": 2022, "title": "A shift from cattle to camel and goat farming can sustain milk production with lower inputs and emissions in north sub-Saharan Africas drylands", "abstract": "Abstract\r\n \r\n Climate change is increasingly putting milk production from cattle-based dairy systems in north sub-Saharan Africa (NSSA) under stress, threatening livelihoods and food security. Here we combine livestock heat stress frequency, dry matter feed production and water accessibility data to understand where environmental changes in NSSAs drylands are jeopardizing cattle milk production. We show that environmental conditions worsened for 17% of the study area. Increasing goat and camel populations by 14% (7.7 million) and 10% (1.2 million), respectively, while reducing the dairy cattle population by 24% (5.9 million), could result in 0.14 Mt (+5.7%) higher milk production, lower water (1,683.6 million m\r\n 3\r\n , 15.3%) and feed resource (404.3 Mt, 11.2%) demandand lower dairy emissions by 1,224.6 MtCO\r\n 2\r\n e (7.9%). Shifting herd composition from cattle towards the inclusion of, or replacement with, goats and camels can secure milk production and support NSSAs dairy production resilience against climate change.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.ECOLIND.2022.108759", "year": 2022, "title": "A generalized model to predict large-scale crop yields integrating", "abstract": "Convenient and reliable large-scale crop yield prediction is needed when formulating administrative plans and ensuring food security, especially under changing climate and international conditions. In this study, we explored Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices- and phenology-based yield prediction generalization model taking the US Corn Belt as an example. We calculated the normalized difference vegetation index (NDVI) and 2-band enhanced vegetation index (EVI2) time series, which were adjusted using greenup dates derived from the Land Cover Dynamics product MCD12Q2. Based on the adjusted VI (NDVI, EVI2) time series, the VI change rate (dVI) time series was calculated, which represents crop growth rate. The first step was to cluster the adjusted VI and dVI time series, called 'greenup groups', according to corresponding greenup dates with a five-day interval. Then in different greenup groups, we constructed empirical univariate models with VI having the maximum correlation with crop yield, and multivariate models with VI and dVI, which were also used to construct the generalized model. After clustering, the days with maximum VI correlation gradually decreased as greenup days increasing, and the univariate VI model and multivariate VI and dVI model performances in different groups improved. The generalized models with specific VI and dVI variables in each group predicted yields of corn and soybean with R2 values mainly ranging from 0.55 to 0.75 and 0.55 to 0.70, while RMSE mainly ranging from 1000 to 1500 kg/ha and 300 to 400 kg/ha for both NDVI and EVI2 from 2008 to 2018 with leave-one-year-out cross-validation for all groups. The model using MODIS data was convenient and scalable with limited data requirements and date-determined variables after greenup, and offered a generalized method to predict crop yields at a large scale before harvest with good performance.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.PCE.2020.102940", "year": 2021, "title": "A novel approach to the use of earth observation to estimate daily evaporation in a sugarcane plantation in Xinavane, Mozambique", "abstract": "Efficient irrigation water management for an 18,000 ha sugarcane plantation in Xinavane in southern Mozambique is a challenge. Sugarcane is an irrigation intensive crop and its productivity is sensitive to water stress. Options to adopt field water management best practices and proper irrigation scheduling are limited due to the lack of plot-level information on the actual crop water use and stress levels throughout the growing season. Due to heterogeneity in cropping calendar within the sugarcane plantation, at a certain point of time, different plots are at different growth stages. This makes scheme level irrigation scheduling complex and calls for frequent crop water use information. To fill this gap, this study presents a novel approach where a combination of satellite imagery with local weather data is used to provide daily evaporation rates. The PriestleyTaylor equation is applied to quantify evaporation (soil evaporation + transpiration) using radiation and temperature data from a meteorological station and spatial albedo estimates derived from the Sentinel-2 satellites. The results show 20 meter resolution maximum crop evaporation estimates can be derived with the proposed methodology. Additionally, the results show NDVI in the last two crop stages is able to distinguish between poor and good performing fields. Therefore, NDVI can be a useful index to estimate actual evaporation. First, the evaporation estimates were corrected for the crop stage using NDVI proxies and an additional stress indicator was used to calculate the actual evaporation flux spatially. The spatial evaporation estimates provide the water manager with information on actual crop water use and biomass development, which is relevant to both crop monitoring and irrigation management water management when drought-related stress is filtered.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1111/GCB.14157", "year": 2018, "title": "Ozone pollution will compromise efforts to increase global wheat", "abstract": "AbstractIntroduction of highperforming crop cultivars and crop/soil water management practices that increase the stomatal uptake of carbon dioxide and photosynthesis will be instrumental in realizing the United Nations Sustainable Development Goal (SDG) of achieving food security. To date, however, global assessments of how to increase crop yield have failed to consider the negative effects of tropospheric ozone, a gaseous pollutant that enters the leaf stomatal pores of plants along with carbon dioxide, and is increasing in concentration globally, particularly in rapidly developing countries. Earlier studies have simply estimated that the largest effects are in the areas with the highest ozone concentrations. Using a modelling method that accounts for the effects of soil moisture deficit and meteorological factors on the stomatal uptake of ozone, we show for the first time that ozone impacts on wheat yield are particularly large in humid rainfed and irrigated areas of major wheatproducing countries (e.g. United States, France, India, China and Russia). Averaged over 20102012, we estimate that ozone reduces wheat yields by a mean 9.9% in the northern hemisphere and 6.2% in the southern hemisphere, corresponding to some 85 Tg (million tonnes) of lost grain. Total production losses in developing countries receiving Official Development Assistance are 50% higher than those in developed countries, potentially reducing the possibility of achieving UN SDG2. Crucially, our analysis shows that ozone could reduce the potential yield benefits of increasing irrigation usage in response to climate change because added irrigation increases the uptake and subsequent negative effects of the pollutant. We show that mitigation of air pollution in a changing climate could play a vital role in achieving the abovementioned UN SDG, while also contributing to other SDGs related to human health and wellbeing, ecosystems and climate change.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1080/20964471.2020.1837529", "year": 2022, "title": "Coupling remote sensing and crop growth model to estimate national wheat yield in Ethiopia", "abstract": "Estimation of crop yield at a regional level is essential for making agricultural planning and addressing food security issues in Ethiopia. Remote sensing observations, particularly the leaf area index (LAI), have a strong relationship with crop yield. This study has proposed an approach to estimate wheat yield at field level and regional scale in Ethiopia by assimilating the retrieved MODIS time-series LAI data into the WOrld FOod STudies (WOFOST) model. To improve the estimation of crop yield in the region, the Ensemble Kalman Filter (EnKF) was used to incorporate the LAI into the WOFOST model. The estimation accuracy of wheat crop yield was validated using field-measured yields collected during the 2018 growing season. Our findings indicated that wheat yield was more precisely estimated by WOFOST (at water-limited mode) with EnKF algorithm (R2 = 0.80 and RMSE = 413 kg ha1) compared to that of without assimilating remotely sensed LAI (R2 = 0.58, RMSE = 592 kg ha1). These results demonstrated that assimilating MODIS-LAI into WOFOST has high potential and practicality to give a reference for wheat yield estimation. The findings from this study can provide information to policy, decision-makers, and other similar sectors to implement an appropriate and timely yield estimation measure.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ESSD-13-4799-2021", "year": 2021, "title": "GCI30: a global dataset of 30 m cropping intensity using multisource remote sensing imagery", "abstract": "Abstract. The global distribution of cropping intensity (CI) is essential to our understanding of agricultural land use management on Earth. Optical remote sensing has revolutionized our ability to map CI over large areas in a repeated and cost-efficient manner. Previous studies have mainly focused on investigating the spatiotemporal patterns of CI ranging from regions to the entire globe with the use of coarse-resolution data, which are inadequate for characterizing farming practices within heterogeneous landscapes. To fill this knowledge gap, in this study, we utilized multiple satellite data to develop a global, spatially continuous CI map dataset at 30 m resolution (GCI30). Accuracy assessments indicated that GCI30 exhibited high agreement with visually interpreted validation samples and in situ observations from the PhenoCam network. We carried out both statistical and spatial comparisons of GCI30 with six existing global CI estimates. Based on GCI30, we estimated that the global average annual CI during 20162018 was 1.05, which is close to the mean (1.09) and median (1.07) CI values of the existing six global CI estimates, although the spatial resolution and temporal coverage vary significantly among products. A spatial comparison with two satellite-based land surface phenology products further suggested that GCI30 was not only capable of capturing the overall pattern of global CI but also provided many spatial details. GCI30 indicated that single cropping was the primary agricultural system on Earth, accounting for 81.57 % (12.28106 km2) of the world's cropland extent. Multiple-cropping systems, on the other hand, were commonly observed in South America and Asia. We found large variations across countries and agroecological zones, reflecting the joint control of natural and anthropogenic drivers on regulating cropping practices. As the first global-coverage, fine-resolution CI product, GCI30 is expected to fill the data gap for promoting sustainable agriculture by depicting worldwide diversity of agricultural land use intensity. The GCI30 dataset is available on Harvard Dataverse: https://doi.org/10.7910/DVN/86M4PO (Zhang et al., 2020).", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGSY.2020.102894", "year": 2020, "title": "Mid-season empirical cotton yield forecasts at fine resolutions using large yield mapping datasets and diverse spatial covariates", "abstract": "Forecasts of crop yield are an important tool for a variety of stakeholders, but most studies produce large-scale, late-season yield forecasts that are not appropriate for farmers. Farmers require forecasts of crop yield mid-season and at fine spatial resolutions to guide site-specific adaptive crop management practices. This study created empirical random forest models to forecast cotton yield mid-season at three different spatial resolutions: 30 m, field, and farm aggregation. Large yield mapping datasets from 14 different seasons were utilised to build the model across 68 different fields from six large cotton farms in eastern Australia. A generic conceptual framework is proposed to empirically model crop yield. This topsaw framework represents the spatial and temporal factors that drive yield, including topography (t), organisms (o), plant measurements (p), soil (s), agronomy/management (a), and weather (w). In this study, the specific predictor variables to represent these driving factors of yield included elevation (t), Normalised Difference Vegetation Index, Enhanced Vegetation Index, MODIS Evapotranspiration (p), gamma radiometrics grid, clay content digital soil map (s), rainfall data, and growing day degrees (w). Forecasts of cotton yield increased in accuracy as the spatial resolution of predictions became coarser. Using a leave-one-year-out cross-validation, cotton yield could be forecasted to an accuracy of 0.42 Lin's Concordance Correlation Coefficient (LCCC) and Root Mean Square Error (RMSE) of 2.11 bales ha1 at 30 m resolution. This improved to a 0.63 LCCC and 1.72 bales ha1 RMSE at the field resolution, and a 0.65 LCCC and 0.77 bales ha1 at the aggregation-scale. As the developed approach solely relied on publicly available predictor variables, there is an opportunity to apply this to any cotton field in Australia, and over a much larger area. Overall, this study is an important step in building an operational approach to forecast mid-season cotton yield at fine spatial resolutions, and has the potential to improve production, input use efficiency, and profitability for individual growers and the Australian Cotton Industry as a whole.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1088/1748-9326/AC0E66", "year": 2021, "title": "Relationship of population migration, crop production pattern, and", "abstract": "Abstract\r\n Global crop production and population distributions have undergone great changes under climate change and socioeconomic development, and have drawn considerable public attention. How to explain the similarity of the migration patterns of crop yield and population density for different countries/regions is still uncertain and worth studying. Here, we estimated the similarity between migrations of main crop caloric yield (i.e. maize, rice, wheat, and soybean) and population density using Frechet distance, and investigated the regression relationship between Frechet distance and related climatic and socioeconomic variables for countries/regions with different economic development stages. The results indicated that different countries/regions showed different Frechet distances during 20002015, with a maximum value of 24.44 for Russia and a minimum value of 0.11 for Georgia. For countries/regions with different economic development stages, the built regression models can explain 39%93% of the variability in the Frechet distance. Log(land area), log(GDP), and log(land area under cereal production) were always included in regression models and had higher importance in explaining the variability of Frechet distance. For the model for all countries/regions, both the log(land area) and log(GDP per capita) may positively link to the Frechet distance. Possible reasons for these results are that countries/regions with high GDP (or GDP per capita) may ease the conflict of land resources between humans and crops to achieve agricultural industrialization, which causes the far connection of the migrations for crop caloric yield and population density. The complicated interactions of crop production, population dynamic, and socioeconomic development should be given greater attention in the future.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1175/WCAS-D-16-0024.1", "year": 2017, "title": "Precipitation drivers of cropping frequency in the Brazilian Cerrado: Evidence and implications for decision-making", "abstract": "Abstract The Amazon basin has been subjected to unprecedented rates of land-use change over the past several decades, primarily as a result of the expansion of agriculture. Enhanced rain forest conservation efforts toward the end of the twentieth century slowed deforestation of the Amazon but, in turn, increased demand for land repurposing in the adjacent Cerrado (savanna) region, where conservation regulations are less strict. To maintain or increase yields while minimizing the need for additional land, agricultural producers adopted a form of intensification in which two rain-fed crops are planted within a single growing season (double cropping). Using 10 years (August 2002 to July 2012) of MODIS and TRMM data, it is demonstrated that there exists a threshold growing season rainfall amount (1759 mm) for double cropping. But more nuanced is the relationship between observable precipitation information available to farmers at the time of planting decision and the choice to double crop in a given year. An evaluation of decision-available precipitation characteristics provides strong evidence for the importance of high rainfall frequency during a critical period prior to, and including, the rainy season onset.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1145/3209811.3212707", "year": 2018, "title": "Deep transfer learning for crop yield prediction with remote sensing data", "abstract": "Accurate prediction of crop yields in developing countries in advance of harvest time is central to preventing famine, improving food security, and sustainable development of agriculture. Existing techniques are expensive and difficult to scale as they require locally collected survey data. Approaches utilizing remotely sensed data, such as satellite imagery, potentially provide a cheap, equally effective alternative. Our work shows promising results in predicting soybean crop yields in Argentina using deep learning techniques. We also achieve satisfactory results with a transfer learning approach to predict Brazil soybean harvests with a smaller amount of data. The motivation for transfer learning is that the success of deep learning models is largely dependent on abundant ground truth training data. Successful crop yield prediction with deep learning in regions with little training data relies on the ability to fine-tune pre-trained models.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.15446/AGRON.COLOMB.V39N1.88979", "year": 2021, "title": "Soybean yield components at different densities and planting seasons in Paraguay", "abstract": "The aim of this research was to evaluate the performance of soybean cultivars using different population densities and planting seasons. The experiments were established using a completely randomized block design with a 1432 factorial arrangement, where factor A consisted of 14 soybean cultivars, factor B were low (177,700 plants ha-1), medium (266,600 plants ha-1), and high (355,500 plants ha-1) population densities, and factor C consisted of early and late planting seasons. We evaluated the number of pods per plant (NPP), number of grains m-2 (NG), 1000-grain weight (TGW), and yield (kg ha-1). The interaction between cultivar and planting season affected the NG, TGW, and yield. Cultivars DM-6563-IPRO, TMG-7062-IPRO, 6505-B, NA-5909-RG, M-6410-IPRO, DM-6262-IPRO, SOJAPAR-R19, 6806-IPRO, 6205-B, M-5947-IPRO and SYN-1163-RR showed higher yields in the early planting season and cultivar NS-5959-IPRO in the late planting season. Cultivars 5907-IPRO and DM-5958 showed similar yields for the two planting seasons evaluated. The highest yields were obtained from a density of 266,600 plants ha-1. The cultivarplanting season interaction affected the TGW, with the early planting season showing a greater TGW for most of the cultivars evaluated. The NPP depended on the interaction between cultivar, density, and planting season. The combination of the NG and the TGW showed a more significant influence on the generation of yield in the cultivars. This study highlights the importance of selecting genotypes according to their response to variations in planting date and plant density. This information could help Paraguayan farmers to maximize production in the same area, optimizing the available resources.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.COMPAG.2020.105943", "year": 2021, "title": "Regional estimation of garlic yield using crop, satellite and climate data in Mexico", "abstract": "Garlic (Allivium sativum L.) has been consumed by humans since the beginning of recorded history. Despite its culinary and economical importance, little efforts are reported in the literature to forecast garlic yield. In this study, we developed the first attempt to predict garlic yield at large scale using crop, satellite (TERRA-MODIS) and climate data (ERA-5). The study area was located in Mexico (2004 2018). We compared the predictive capacity of three Machine Learning (ML) methods: generelised linear model (glm), support vector machine radial (svmR) and random forest (rf); as well as different combinations of predictors. The best performance was obtained by the svmR model (R2 = 0.68 and %RMSE = 20.08%) which combined YieldBaseLine, NDVI and climate data under Feature Selection scenario (FS) = 0.90. The rf method performed similarly well (R2 = 0.66), while glm achieved lower performance (R2 = 0.61). To test the predictive capacity of the models in practice, we additionally used a leave-one-year-out method in a time-wise manner. Models gradually improved over the years as more data was incorporated for training. The svmR and rf methods presented an overall performance of R2 ~0.60 (%RMSE ~20.5%), reaching the highest accuracy (R2 = 0.78, %RMSE ~16.6%) in 2014. Both approaches reveal the potentiality of the proposed models to account for the inter-annual and spatial garlic yield variability in Mexico. This procedure can be adjusted and used for other crop types or locations.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.FISHRES.2019.105338", "year": 2019, "title": "Distribution of Antarctic toothfish Dissostichus mawsoni along East Antarctica: Environmental drivers and management implications", "abstract": "As Antarctic fish species experience increasing anthropogenic pressures there is a growing need to characterise the structure and function of their populations and understand how they may respond to changes in their environment. We integrated fishery-dependent and environmental data from years 20032017 to investigate the distribution of Antarctic toothfish Dissostichus mawsoni along a c. 3000 nm expanse of the shelf and slope along East Antarctica (30150 E). Spatially-explicit generalised additive mixed models were used to characterise the environmental drivers of relative abundance, mean individual weight, maturity-stage composition and sex ratio. Antarctic toothfish were not randomly distributed across the region, and spatial variations were characterised by complex relationships involving topography, temperature, salinity and sea ice. In particular, catch rates were highest at depths between 10001700 m. Mean weight and the proportion of fish that were mature both increased with depth and decreased with bottom temperature. Model predictions were also used to develop hypotheses relating to population function, including the location of nursery and spawning areas. This characterisation of the population can facilitate evaluation of fishing impacts in East Antarctica, and improve our understanding of the role of toothfish in Antarctic and Southern Ocean ecosystems.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/HESS-26-5373-2022", "year": 2022, "title": "FarmCan: a physical, statistical, and machine learning model to forecast crop water deficit for farms", "abstract": "In the coming decades, a changing climate, the loss of high-quality land, the slowing in the annual yield of cereals, and increasing fertilizer use indicate that better agricultural water management strategies are needed. In this study, we designed FarmCan, a novel, robust remote sensing and machine learning (ML) framework to forecast farms' needed daily crop water quantity or needed irrigation (NI). We used a diverse set of simulated and observed near-real-time (NRT) remote sensing data coupled with a random forest (RF) algorithm and inputs about farm-specific situations to predict the amount and timing of evapotranspiration (ET), potential ET (PET), soil moisture (SM), and root zone soil moisture (RZSM). Our case study of four farms in the Canadian Prairies Ecozone (CPE) shows that 8 d composite precipitation (P) has the highest correlation with changes () of RZSM and SM. In contrast, 8 d PET and 8 d ET do not offer a strong correlation with 8 d P. Using R2, root mean square error (RMSE), and KlingGupta efficiency (KGE) indicators, our algorithm could reasonably calculate daily NI up to 14 d in advance. From 2015 to 2020, the R2 values between predicted and observed 8 d ET and 8 d PET were the highest (80 % and 54 %, respectively). The 8 d NI also had an average R2 of 68%. The KGE of the 8 d ET and 8 d PET in four study farms showed an average of 0.71 and 0.50, respectively, with an average KGE of 0.62. FarmCan can be used in any region of the world to help stakeholders make decisions during prolonged periods of drought or waterlogged conditions, schedule cropping and fertilization, and address local government policy concerns.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1111/GCBB.12411", "year": 2017, "title": "Contribution of above- and belowground bioenergy crop residues to soil", "abstract": "GHG mitigation by bioenergy crops depends on crop type, management practices, and the input of residue carbon (C) to the soil. Perennial grasses may increase soil C compared to annual crops because of more extensive root systems, but it is less clear how much soil C is derived from above\u2011 vs. belowground inputs. The objective of this study was to synthesize the existing knowledge regarding soil C inputs from above\u2011 and belowground crop residues in regions cultivated with sugarcane, corn, and miscanthus, and to predict the impact of residue removal and tillage on soil C stocks. The literature review showed that aboveground inputs to soil C (to 1\u2011m depth) ranged from 70% to 81% for sugarcane and corn vs. 40% for miscanthus. Modeled aboveground C inputs (to 30 cm depth) ranged from 54% to 82% for sugarcane, but were 67% for miscanthus. Because 50% of observed miscanthus belowground biomass is below 30 cm depth, it may be necessary to increase the depth of modeled soil C dynamics to reconcile modeled belowground C inputs with measured. Modeled removal of aboveground corn residue (25\u2013100%) resulted in C stock reduction in areas of corn\u2013corn\u2013soybean rotation under conventional tillage, while no\u2011till management lessoned this impact. In sugarcane, soil C stocks were reduced when total aboveground residue was removed at one site, while partial removal of sugarcane residue did not reduce soil C stocks in either area. This study suggests that aboveground crop residues were the main C\u2011residue source to the soil in the current bioethanol sector (corn and sugarcane) and the indiscriminate removal of crop residues to produce cellulosic biofuels can reduce soil C stocks and reduce the environmental benefits of bioenergy. Moreover, a switch to feedstocks such as miscanthus with more allocation to belowground C could increase soil C stocks at a much faster rate.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JCLEPRO.2019.119900", "year": 2020, "title": "Balancing food production within the planetary water boundary", "abstract": "Freshwater use is recognized as one of the nine planetary boundaries. However, water scarcity is a local or regional phenomenon, meaning that the global boundary must be spatially downscaled to reflect differences in water availability. In China, as in most countries, irrigation is the major freshwater user, closely linking food security to the freshwater boundary. To provide evidence supporting environmentally sustainable water use in Chinas food production, this study explores how a grain production shift affects the national water-scarcity footprint (WSF) and the potential to reach sustainable water use limits while maintaining the current grain production level. We found that the historical breadbasket shift towards water-scarce northern regions has increased the WSF by 40% from 1980 to 2015. To operate within the boundary, national irrigation needs to be reduced by 18% in hotspot regions, with implications of a 21% loss of grain production. However, this loss can be reduced to around 8% by closing yield gaps in water-rich regions. It demonstrates the high potential of integrating crop redistribution and closing yield gaps to achieve grain production goals within freshwater boundaries. This Chinese case study can be representative of the challenges faced by many of the worlds countries, where pressures on land and water resources are high and a sustainable means of increasing food supply must be found.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1111/EFF.12650", "year": 2022, "title": "Forested watersheds mitigate the thermal degradation of headwater fish assemblages under future climate change", "abstract": "Certain habitat features of stream ecosystems can reduce their sensitivity to climate change and help protect the integrity of cold\u2011water aquatic resources. Identifying such features is imperative for conserving the climate refugia of cold\u2011water species. Using a combination of stream temperature and fish assemblage data, we quantified thermal sensitivities of 192 headwater streams in Northwest Pennsylvania to identify which landscape features best explained stream susceptibility to temperature change. We then projected changes in native brook trout (Salvelinus fontinalis) distributions, non\u2011native brown trout (Salmo trutta) distributions and declines in cold\u2011water thermal integrity under future climate warming and land use change scenarios. Brook trout were predicted to become increasingly relegated to smaller streams under future stream warming. However, we found that streams with intact forest cover at the watershed level had low thermal sensitivities, which slowed rates of projected warming. As a result, streams with forested watersheds were predicted to have smaller declines in thermal integrity and lower extirpation probabilities of brook trout. Additionally, non\u2011native brown trout were not predicted to expand distributions under projected warming, suggesting minimal synergistic effects between non\u2011native species and climate change. Forest cover buffers headwater streams from the effects of global change, similar to how groundwater inputs reduce the rate of stream warming. Forest restoration at riparian and watershed levels should help mitigate thermal\u2011induced degradation of cold\u2011water aquatic resources.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.COMPAG.2018.05.035", "year": 2018, "title": "Wheat and maize yield forecasting for the Tisza river catchment using MODIS NDVI time series and reported crop statistics", "abstract": "Stakeholders, policy makers, government planners and agricultural market participants in Central Eastern Europe require accurate and timely information about wheat and maize yield and production. The study site, the lowlands (altitude below 200 m) of the Tisza river catchment is by far the most important wheat and corn producing region in the Carpathian basin, and even in Central Eastern Europe. The conventional sampling of on-field data and data processing for crop forecasting requires significant amounts of time before official reports can be released. Several studies have shown that wheat and maize yield can be effectively forecast using satellite remote sensing. In this study, a freely available MODIS NDVI satellite data based wheat and maize yield forecasting methodology was developed and evaluated for estimating yield losses effected by drought. Wheat and maize yield was derived by regressing reported yield values against time series of 15 different peak-season MODIS-derived NDVI. The lowest RMSE values at the river basin level for both wheat and maize yield forecast versus reported yield were found when using at least six or more years of training data. Wheat forecast for the 2000 to 2015 growing seasons were within 0.819% and 19.08% of final reported yield values. Maize forecast at county level for the 2000 to 2015 growing seasons were within 0.299% and 17.14% of final reported yield values. The NashSutcliffe efficiency index (E1) is positive with E1 = 0.322 in the case of wheat forecast, and with E1 = 0.401 in the case of maize forecast, which means the developed and evaluated forecasting method performs acceptable forecast efficiency. Nevertheless the occurrence of extreme drought or extreme precipitation can alter the forecasting efficiency resulting over or underestimation. Overall statement, which based on MODIS NDVI, possible yield losses can easily be forecasted 68 weeks before harvesting and applying simple threshold levels, yield losses can be mapped simply.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/SU11215897", "year": 2019, "title": "Finding a Suitable Niche for Cultivating Cactus Pear (Opuntia ficus-indica) as an Integrated Crop in Resilient Dryland Agroecosystems of India", "abstract": "Climate change poses a significant threat to agroecosystems, especially in the dry areas, characterized by abrupt precipitation pattern and frequent drought events. Ideal crops, tolerant to these events, such as cactus, can perform well under such changing climatic conditions. This study spatially maps land suitability for cactus (Opuntia ficus-indica) cultivation in India using the analytical hierarchical process (AHP). Nine essential growth factors that include the climate and edaphic components were considered for the period 2000 to 2007. About 32% of the total geographic area of the country is in the high to moderate suitable category. Remaining 46% falls under the marginally suitable and 22% under the low to very low suitable category. The suitability analysis, based on the precipitation anomaly (20082017), suggests a high probability of cactus growth in the western and east-central part of India. The relationship with aridity index shows a decreasing rate of suitability with the increase of aridity in the western and east-central provinces (~1 to 2). We conclude that integrating cactus into dryland farming systems and rangelands under changing climate can be one plausible solution to build resilient agro-ecosystems that provide food and fodder while enhancing the availability of ecosystem services.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/RS12182957", "year": 2020, "title": "Mapping crop types in southeast India with smartphone crowdsourcing and deep learning", "abstract": "High resolution satellite imagery and modern machine learning methods hold the potential to fill existing data gaps in where crops are grown around the world at a sub-field level. However, high resolution crop type maps have remained challenging to create in developing regions due to a lack of ground truth labels for model development. In this work, we explore the use of crowdsourced data, Sentinel-2 and DigitalGlobe imagery, and convolutional neural networks (CNNs) for crop type mapping in India. Plantix, a free app that uses image recognition to help farmers diagnose crop diseases, logged 9 million geolocated photos from 20172019 in India, 2 million of which are in the states of Andhra Pradesh and Telangana in India. Crop type labels based on farmer-submitted images were added by domain experts and deep CNNs. The resulting dataset of crop type at coordinates is high in volume, but also high in noise due to location inaccuracies, submissions from out-of-field, and labeling errors. We employed a number of steps to clean the dataset, which included training a CNN on very high resolution DigitalGlobe imagery to filter for points that are within a crop field. With this cleaned dataset, we extracted Sentinel time series at each point and trained another CNN to predict the crop type at each pixel. When evaluated on the highest quality subset of crowdsourced data, the CNN distinguishes rice, cotton, and other crops with 74% accuracy in a 3-way classification and outperforms a random forest trained on harmonic regression features. Furthermore, model performance remains stable when low quality points are introduced into the training set. Our results illustrate the potential of non-traditional, high-volume/high-noise datasets for crop type mapping, some improvements that neural networks can achieve over random forests, and the robustness of such methods against moderate levels of training set noise. Lastly, we caution that obstacles like the lack of good Sentinel-2 cloud mask, imperfect mobile device location accuracy, and preservation of privacy while improving data access will need to be addressed before crowdsourcing can widely and reliably be used to map crops in smallholder systems.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1017/S0030605321001538", "year": 2022, "title": "Effect of free-ranging cattle on mammalian diversity: an Austral Yungas case study", "abstract": "Abstract\r\n \r\n Extensive cattle ranging is an important economic activity in mountains, with diverse effects on native mammal communities. The effects of cattle\r\n Bos taurus\r\n can be negative, positive or neutral, mostly depending on the stocking rate. We examined the effect of cattle on the diversity and abundance of native mammalian species in the Austral Yungas region of Argentina, considering environmental variables, land protection status, and human influence. Using 12,512 trap-nights from 167 camera-trap stations over 11 years (20092019), we calculated a relative abundance index using camera events and used generalized linear models to estimate the effect of cattle on small mammals, large herbivores, species of conservation concern and felids. Cattle had different effects on each group of native mammals. We observed a lower abundance of large native herbivores and the absence of small mammals in areas with high cattle abundance. The tapir\r\n Tapirus terrestris,\r\n jaguar\r\n Panthera onca\r\n and white-lipped peccary\r\n Tayassu pecari\r\n are rare in the Yungas and therefore potentially vulnerable to extinction there. Conservation of small felids and low cattle abundance could be compatible, but felids are threatened by other anthropogenic influences. Native mammalian diversity and richness were related to land protection status. The entire ecoregion is potentially suitable for cattle, suggesting the potential for further threats, and that cattle should be excluded from strictly protected areas. To ensure extensive cattle ranging is compatible with wildlife conservation in areas where exclusion is not possible, we recommend improved management of cattle and moderate stocking rates.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.13031/JA.15181", "year": 2022, "title": "Assessing The Effects Of A Winter Wheat Cover Crop On Soil Water Use, Cotton Yield, And Soil Organic Carbon In No-Till Cotton Production Systems", "abstract": "Highlights\r\n \r\n \r\n \r\n \r\n Soil water depleted by the cover crop was quickly replenished by spring precipitation.\r\n \r\n \r\n Higher soil water was maintained during the cotton growing season under the cover crop treatment.\r\n \r\n \r\n Cover crops improved soil organic carbon under both irrigated and dryland conditions.\r\n \r\n \r\n Cover crops enhanced crop water productivity under both irrigated and dryland conditions.\r\n \r\n \r\n \r\n \r\n Abstract.\r\n Cover crops provide many soil health benefits to agricultural systems. An interest in growing cover crops in cotton (Gossypium hirsutum L.) production systems has been increasing in the Texas Rolling Plains (TRP) region. Due to limited rainfall and groundwater availability, producers in this semi-arid region are concerned that winter cover crops can reduce soil water availability for a subsequent cotton crop. In addition, the long-term effects of cover crops on soil organic carbon (SOC) are not well studied in this region. The overall goal of this study was to assess the long-term effects of growing a winter wheat (Triticum aestivum) cover crop on soil water, SOC, seed cotton yield, and crop water productivity (CWP) under irrigated and dryland cotton production systems using the Decision Support System for Agrotechnology Transfer (DSSAT) model. Measured data from cover crop experiments conducted at the Texas A&M AgriLife Research Station at Chillicothe from 2011 to 2020 were used to evaluate the CROPGRO-Cotton and CERES-Wheat modules in the DSSAT Cropping System Model. The average percent error (PE) between the simulated and measured seed cotton yield was 0.3% and -0.9%, and that between the simulated and measured aboveground wheat biomass was 1.4% and -3.4% during the calibration and evaluation periods, respectively. For the simulation of SOC, the PE was 8.5% and 7.6% during the calibration and evaluation periods, respectively. Long-term (2001 to 2020) simulations showed that soil water was reduced substantially by the winter wheat cover crop before its termination. However, depleted soil water was quickly replenished by spring precipitation and maintained at a higher level during the cotton growing season. Winter wheat cover crops can potentially improve SOC in irrigated and dryland cotton production systems. The CWP of cotton also improved with a winter wheat cover crop under both irrigated and dryland conditions. We concluded that cover crops could potentially improve soil health and provide a sustainable environment for TRP cotton production. Keywords: CERES-Wheat, CROPGRO-Cotton, DSSAT, Soil health, Texas Rolling Plains (TRP).", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGRFORMET.2021.108528", "year": 2021, "title": "Gap-filling eddy covariance methane fluxes: Comparison of machine learning model predictions and uncertainties at FLUXNET-CH4 wetlands", "abstract": "Time series of wetland methane fluxes measured by eddy covariance require gap-filling to estimate daily, seasonal, and annual emissions. Gap-filling methane fluxes is challenging because of high variability and complex responses to multiple drivers. To date, there is no widely established gap-filling standard for wetland methane fluxes, with regards both to the best model algorithms and predictors. This study synthesizes results of different gap-filling methods systematically applied at 17 wetland sites spanning boreal to tropical regions and including all major wetland classes and two rice paddies. Procedures are proposed for: 1) creating realistic artificial gap scenarios, 2) training and evaluating gap-filling models without overstating performance, and 3) predicting half-hourly methane fluxes and annual emissions with realistic uncertainty estimates. Performance is compared between a conventional method (marginal distribution sampling) and four machine learning algorithms. The conventional method achieved similar median performance as the machine learning models but was worse than the best machine learning models and relatively insensitive to predictor choices. Of the machine learning models, decision tree algorithms performed the best in cross-validation experiments, even with a baseline predictor set, and artificial neural networks showed comparable performance when using all predictors. Soil temperature was frequently the most important predictor whilst water table depth was important at sites with substantial water table fluctuations, highlighting the value of data on wetland soil conditions. Raw gap-filling uncertainties from the machine learning models were underestimated and we propose a method to calibrate uncertainties to observations. The python code for model development, evaluation, and uncertainty estimation is publicly available. This study outlines a modular and robust machine learning workflow and makes recommendations for, and evaluates an improved baseline of, methane gap-filling models that can be implemented in multi-site syntheses or standardized products from regional and global flux networks (e.g., FLUXNET).", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-16-12005-2016", "year": 2016, "title": "Greenhouse gas simulations with a coupled meteorological and transport model: the predictability of CO2", "abstract": "Abstract. A new model for greenhouse gas transport has been developed based on Environment and Climate Change Canada's operational weather and environmental prediction models. When provided with realistic posterior fluxes for CO2, the CO2 simulations compare well to NOAA's CarbonTracker fields and to near-surface continuous measurements, columns from the Total Carbon Column Observing Network (TCCON) and NOAA aircraft profiles. This coupled meteorological and tracer transport model is used to study the predictability of CO2. Predictability concerns the quantification of model forecast errors and thus of transport model errors. CO2 predictions are used to compute modeldata mismatches when solving flux inversion problems and the quality of such predictions is a major concern. Here, the loss of meteorological predictability due to uncertain meteorological initial conditions is shown to impact CO2 predictability. The predictability of CO2 is shorter than that of the temperature field and increases near the surface and in the lower stratosphere. When broken down into spatial scales, CO2 predictability at the very largest scales is mainly due to surface fluxes but there is also some sensitivity to the land and ocean surface forcing of meteorological fields. The predictability due to the land and ocean surface is most evident in boreal summer when biospheric uptake produces large spatial gradients in the CO2 field. This is a newly identified source of uncertainty in CO2 predictions but it is expected to be much less significant than uncertainties in fluxes. However, it serves as an upper limit for the more important source of transport error and loss of predictability, which is due to uncertain meteorological analyses. By isolating this component of transport error, it is demonstrated that CO2 can only be defined on large spatial scales due to the presence of meteorological uncertainty. Thus, for a given model, there is a spatial scale below which fluxes cannot be inferred simply due to the fact that meteorological analyses are imperfect. These unresolved spatial scales correspond to small scales near the surface but increase with altitude. By isolating other components of transport error, the largest or limiting error can be identified. For example, a model error due to the lack of convective tracer transport was found to impact transport error on the very largest (wavenumbers less than 5) spatial scales. Thus for wavenumbers greater than 5, transport model error due to meteorological analysis uncertainty is more important for our model than the lack of convective tracer transport.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S10668-021-01677-6", "year": 2021, "title": "Spatiotemporal variability of atmospheric CO2 concentration and controlling factors over sugarcane cultivation areas in southern Brazil", "abstract": "With the advancement of remote sensing, it is now possible to identify and characterize greenhouse gas emissions under deferment land uses. Given the above, this study aimed to characterize the spatialtemporal variability and the main factors controlling the average atmospheric CO2 column (Xco2) in the macroregion of Ribeirao Preto (MRP), Sao Paulo, a significant sugarcane producer in Brazil. We obtained remote sensing data from January 2015 to December 2018. The variables used were Xco2 and sun-induced fluorescence of chlorophyll (SIF) by NASA's Orbiting Carbon Observatory-2 satellite (OCO-2), relative humidity (RH), global radiation (Qg), and the average temperature at 2 m (T2m) by the NASA-POWER platform, and leaf area index (LAI) and evapotranspiration by PenmanMonteith (ET) by MODIS sensor. We evaluated the data in trimesters averages, where descriptive statistics, Pearson correlation and linear regression have been applied. The spatial distribution was made by the inverse distance weighted (IDW). The minimum (390.40 0.41 ppm) and maximum (394.75 0.34 ppm) mean of Xco2 was observed in the first quarter of 2015 and third quarter of 2017. The Xco2 obtained negative correlations with the SIF (0.81), LAI (0.81), RH (0.74), ET (0.84), and Qg (0.51). Hotspots and coldspots of Xco2 tend to vary over the years. We conclude that the temporal variation of Xco2 above sugarcane areas in southern Brazil is well represented by a periodic function. Our results indicate photosynthesis and soil exposure after harvest are factors that could act as source and sink of CO2.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2022EA002609", "year": 2022, "title": "Downward Trend in Methane Detected in a Northern Colorado Oil and Gas Production Region Using AIRS Satellite Data", "abstract": "The oil and gas (O&G) sector is estimated to be the largest contributor to anthropogenic methane (CH4) emissions in Colorado. Since 2004, the State of Colorado has implemented multiple regulations to significantly reduce emissions from the O&G sector. The Denver-Julesburg Basin (DJ Basin) is a significant O&G producing region in northern Colorado, and O&G production here has steadily increased over the last decade. To assess CH4 trends in Northern Colorado, we selected CH4 retrievals from the NASA Atmospheric Infrared Sounder (AIRS) instrument for 2003-2020. The study grid cell includes Denver, Boulder, and much of the dense O&G production in the DJ Basin. We computed mean June-August ascending node AIRS 700 hPa CH4 for each year and subtracted mean June-August CH4 sampled at NOAA's Niwot Ridge (NWR) station, a high-altitude background site. Differences represent estimated enhancement over background. Linear regression shows an annual change of \u22122.84 ppb \u00b1 0.8 ppb from 2012 to 2020 (R2 0.90) and an estimated reduction of 56% for 2012-2020, despite substantial increases in O&G production. Local CH4 enhancement is strongly correlated with surface measurements of ethane at Platteville which is in the center of the O&G fields (correlation coefficient 0.96), and this is evidence that reductions in O&G emissions are driving reductions in CH4. We conclude that AIRS CH4 can be used to measure the efficacy of emissions control programs in this region and that regulatory requirements are having an effect.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1073/PNAS.1516017113", "year": 2016, "title": "Cold season emissions dominate the Arctic tundra methane budget", "abstract": "Significance\r\n Arctic ecosystems are major global sources of methane. We report that emissions during the cold season (September to May) contribute 50% of annual sources of methane from Alaskan tundra, based on fluxes obtained from eddy covariance sites and from regional fluxes calculated from aircraft data. The largest emissions were observed at the driest site (<5% inundation). Emissions of methane in the cold season are linked to the extended zero curtain period, where soil temperatures are poised near 0 C, indicating that total emissions are very sensitive to soil climate and related factors, such as snow depth. The dominance of late season emissions, sensitivity to soil conditions, and importance of dry tundra are not currently simulated in most global climate models.\r\n , \r\n \r\n Arctic terrestrial ecosystems are major global sources of methane (CH\r\n 4\r\n ); hence, it is important to understand the seasonal and climatic controls on CH\r\n 4\r\n emissions from these systems. Here, we report year-round CH\r\n 4\r\n emissions from Alaskan Arctic tundra eddy flux sites and regional fluxes derived from aircraft data. We find that emissions during the cold season (September to May) account for 50% of the annual CH\r\n 4\r\n flux, with the highest emissions from noninundated upland tundra. A major fraction of cold season emissions occur during the zero curtain period, when subsurface soil temperatures are poised near 0 C. The zero curtain may persist longer than the growing season, and CH\r\n 4\r\n emissions are enhanced when the duration is extended by a deep thawed layer as can occur with thick snow cover. Regional scale fluxes of CH\r\n 4\r\n derived from aircraft data demonstrate the large spatial extent of late season CH\r\n 4\r\n emissions. Scaled to the circumpolar Arctic, cold season fluxes from tundra total 12 5 (95% confidence interval) Tg CH\r\n 4\r\n y\r\n 1\r\n , 25% of global emissions from extratropical wetlands, or 6% of total global wetland methane emissions. The dominance of late-season emissions, sensitivity to soil environmental conditions, and importance of dry tundra are not currently simulated in most global climate models. Because Arctic warming disproportionally impacts the cold season, our results suggest that higher cold-season CH\r\n 4\r\n emissions will result from observed and predicted increases in snow thickness, active layer depth, and soil temperature, representing important positive feedbacks on climate warming.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/NGEO434", "year": 2009, "title": "Large N2O emissions from cryoturbated peat soil in tundra", "abstract": "Nitrous oxide is a potent greenhouse gas whose concentration is increasing in the atmosphere. So far, the highest terrestrial nitrous oxide emissions have been measured in agricultural and tropical soils, and nitrous oxide emissions from northern natural soils have been considered negligible. Pristine tundra, one of the largest natural land cover types in the world, is a mosaic of different surface types including bare surfaces created by cryoturbation. Here we used a static chamber method to measure nitrous oxide emissions from the discontinuous permafrost zone in subarctic East European tundra. We show that nitrous oxide emissions from bare peat surfaces in the region, known as peat circles, range between 0.9 and 1.4g nitrous oxide m-2 from June to October, and are equivalent to those from tropical and agricultural soils. Extrapolation of our data to the whole Arctic reveals that the emissions from these hot spots could amount to ~0.1Tg nitrous oxide yr-1, corresponding to 4% of the global warming potential of Arctic methane emissions at present. Therefore, not only carbon, but also nitrogen stored in permafrost soils, has to be considered when assessing the present and future climatic impact of tundra.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/S41598-018-22801-Z", "year": 2018, "title": "The Transpolar Drift conveys methane from the Siberian Shelf to the central Arctic Ocean", "abstract": "Methane sources and sinks in the Arctic are poorly quantified. In particular, methane emissions from the Arctic Ocean and the potential sink capacity are still under debate. In this context sea ice impact on and the intense cycling of methane between sea ice and Polar surface water (PSW) becomes pivotal. We report on methane super- and under-saturation in PSW in the Eurasian Basin (EB), strongly linked to sea ice-ocean interactions. In the southern EB under-saturation in PSW is caused by both inflow of warm Atlantic water and short-time contact with sea ice. By comparison in the northern EB long-time sea ice-PSW contact triggered by freezing and melting events induces a methane excess. We reveal the Ttranspolar Drift Stream as crucial for methane transport and show that inter-annual shifts in sea ice drift patterns generate inter-annually patchy methane excess in PSW. Using backward trajectories combined with 18O signatures of sea ice cores we determine the sea ice source regions to be in the Laptev Sea Polynyas and the off shelf regime in 2011 and 2015, respectively. We denote the Transpolar Drift regime as decisive for the fate of methane released on the Siberian shelves.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1080/07038992.2017.1259556", "year": 2016, "title": "Using Landsat time-series and LiDAR to inform aboveground forest biomass baselines in northern Minnesota, USA", "abstract": "The publicly accessible archive of Landsat imagery and increasing regional-scale LiDAR acquisitions offer an opportunity to periodically estimate aboveground forest biomass (AGB) from 1990 to the present to align with the reporting needs of National Greenhouse Gas Inventories (NGHGIs). This study integrated Landsat time-series data, a state-wide LiDAR dataset, and a recent cycle of the national forest inventory (NFI) records in Minnesota, USA, to obtain a spatially explicit inventory of AGB across a large region of space and time back to the 1990 baseline used by the US NGHGI. Pixel-level polynomial models were fit to 6 time-series metrics of Landsat data to obtain fitted predictors that were ultimately coupled with the NFI data in a nonparametric modeling framework to map temporal AGB baselines. Eighteen candidate models, formulated using different combinations of LiDAR and Landsat metrics, revealed that the model using both Landsat and LiDAR metrics consistently performed better than the alternative models. The RMSE of the model using both Landsat and LiDAR was 27.2 Mg ha1, against 31.39 Mg ha1 for the model using only LiDAR metrics. We conclude that the fitted Landsat-based model (RMSE = 47.64 Mg ha1) provides acceptable accuracy for the 1990-baseline mapping of AGB.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2020JG005647", "year": 2020, "title": "Seasonality and Budgets of Soil Greenhouse Gas Emissions From a Tropical", "abstract": "Limited information on greenhouse gas emissions from tropical dry forest soils still hinders the assessment of the sources/sinks from this ecosystem and their contribution at global scales. Particularly, rewetting events after the dry season can have a significant effect on soil biogeochemical processes and associated exchange of greenhouse gases. This study evaluated the temporal variation and annual fluxes of CO2, N2O, and CH4 from soils in a tropical dry forest successional gradient. After a prolonged drought of 5 months, large emissions pulses of CO2 and N2O were observed at all sites following first rain events, caused by the \"Birch effect,\" with a significant effect on the net ecosystem exchange and the annual emissions budget. Annual CO2 emissions were greatest for the young forest (8,556 kg C ha-1 yr-1) followed by the older forest (7,420 kg C ha-1 yr-1) and the abandoned pasture (7,224 kg C ha-1 yr-1). Annual emissions of N2O were greatest for the forest sites (0.39 and 0.43 kg N ha-1 yr-1) and least in the abandoned pasture (0.09 kg N ha-1 yr-1). CH4 uptake was greatest in the older forest (-2.61 kg C ha-1 yr-1) followed by the abandoned pasture (-0.69 kg C ha-1 yr-1) and the young forest (-0.58 kg C ha-1 yr-1). Fluxes were mainly influenced by soil moisture, microbial biomass, and soil nitrate and ammonium concentrations. Annual CO2 and N2O soil fluxes of tropical dry forests in this study and others from the literature were much lower than the annual fluxes in wetter tropical forests. Conversely, tropical dry forests and abandoned pastures are on average stronger sinks for CH4 than wetter tropical forests.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1002/2016GB005460", "year": 2017, "title": "Anthropogenic CO2 accumulation and uptake rates in the Pacific Ocean", "abstract": "AbstractThe anthropogenic CO2 accumulation rate for the Pacific Ocean was estimated from the decrease in 13C of the dissolved inorganic carbon measured on six World Ocean Circulation Experiment cruises during the 1990s and repeated during Climate Variability and Predictability in the 2000s. A mean depthintegrated anthropogenic 13C change of 83 20 m decade1 was estimated for the basin by using the multiple linear regression approach. The largest anthropogenic 13C decreases occurred between 40S and 60S, whereas the smallest decreases occurred in the Southern Ocean and subpolar North Pacific. A mean anthropogenic CO2 accumulation rate of 0.41 0.13 mol C m2 yr1 (0.82 0.26 Pg C yr1) was determined based on observed 13C changes and is in agreement with previous observation and modelbased estimates. The mean dissolved inorganic carbon DIC13 inventory change of 178 43 mol m2 decade1 was primarily the result of airsea CO2 exchange acting on the measured airsea 13C disequilibrium of ~ 1.2 0.1. Regional differences between the DIC13 inventory change and airsea 13CO2 flux yielded net anthropogenic CO2 uptake rates (independent of pCO2) that ranged from ~0 to 1 mol m2 yr1 and basinwide mean of 1.2 1.5 Pg C yr1. High rates of surface ocean DIC increase and 13C decrease observed in the Drake Passage (53S60S) support above average anthropogenic CO2 accumulation since 2005. Observed 13C changes in the Pacific Ocean indicate that ocean transport significantly impacted the anthropogenic CO2 distribution and illustrate the utility of 13C as a tracer to unravel the processes controlling the present and future accumulation of anthropogenic CO2 in the ocean.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.3390/AGRONOMY11071323", "year": 2021, "title": "Agricultural Greenhouse Gas Emissions in a Data-Scarce Region Using a", "abstract": "Climate change may impact agricultural greenhouse gas emissions (GHGs) and yields under higher temperatures, higher atmospheric CO2 concentrations, and variable precipitations. This calls for adaptation strategies to optimize agricultural productions with minimal GHGs. This study aimed to identify these optimum agricultural managements in response to current and projected climatic scenarios for the Choctawhatchee Basin in Southeastern USA, an experimentally unexplored data-scarce region lacking validation data. This scenario-based modeling study analyzed a total of 1344 scenarios consisting of four major crops, eight managements (varying tillage, manuring, and residue), and forty climatic combinations under current as wells as two representative concentration pathways with process-based Denitrification and Decomposition (DNDC) model. The results indicated that the regions GHGs and yields were most affected by higher temperatures (+3 C) and extreme precipitation changes (40%), while high atmospheric CO2 concentrations exerted positive fertilization effects. The manure-related and higher residue incorporation scenarios were found to be better options in varying climates with minimal present global warming potentials (GWP) of 0.23 k to 29.1 k MT equivalent CO2. As such, the study presented climate change impacts and potential mitigation options in the study region while presenting a framework to design GHG mitigation in similar data-scarce regions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/J.1600-0889.2010.00485.X", "year": 2010, "title": "Assessing the impact of crops on regional CO2\n fluxes and atmospheric concentrations", "abstract": "Human conversion of natural ecosystems to croplands modifies not only the exchange of water and energy between the surface and the atmosphere, but also carbon fluxes. To investigate the impacts of crops on carbon fluxes and resulting atmospheric CO2 concentrations in the mid-continent region of the United States, we coupled a crop-specific phenology and physiology scheme for corn, soybean and wheat to the coupled ecosystem-atmosphere model SiB3-RAMS. Using SiBcrop-RAMS improved carbon fluxes at the local scale and had regional impacts, decreasing the spring uptake and increasing the summer uptake over the mid-continent. The altered fluxes changed the mid-continent atmospheric CO2 concentration field at 120 m compared to simulations without crops: concentrations increased in May and decreased >20 ppm during July and August, summer diurnal cycle amplitudes increased, synoptic variability correlations improved and the gradient across the mid-continent region increased. These effects combined to reduce the squared differences between the model and high-precision tower CO2 concentrations by 20%. Synoptic transport of the large-scale N-S gradient caused significant day-to-day variability in concentration differences measured between the towers. This simulation study shows that carbon exchange between crops and the atmosphere significantly impacts regional CO2 fluxes and concentrations.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-16-9149-2016", "year": 2016, "title": "Large XCH4 anomaly in summer 2013 over northeast Asia observed by GOSAT", "abstract": "Abstract. Extremely high levels of column-averaged dry-air mole fractions of atmospheric methane (XCH4) were detected in August and September 2013 over northeast Asia ( 20 ppb above the averaged summertime XCH4 over 20092012, after removing a long-term trend), as being retrieved from the Short-Wavelength InfraRed (SWIR) spectral data observed with the Thermal And Near-infrared Sensor for carbon Observation Fourier Transform Spectrometer (TANSO-FTS) onboard Greenhouse Gases Observing Satellite (GOSAT). Similar enhancements of XCH4 were also observed by the ground-based measurements at two Total Carbon Column Observing Network (TCCON) sites in Japan. The analysis of surface CH4 concentrations observed at three monitoring sites around the Japan archipelago suggest that the extreme increase of XCH4 has occurred in a limited area. The model analysis was conducted to investigate this anomalously high XCH4 event, using an atmospheric transport model. The results indicate that the extreme increase of XCH4 is attributed to the anomalous atmospheric pressure pattern over East Asia during the summer of 2013, which effectively transported the CH4-rich air to Japan from the strong CH4 source areas in east China. The two Japanese TCCON sites, 1000 km eastwest apart each other, coincidentally located along the substantially CH4-rich air flow from east China. This analysis demonstrates the capability of GOSAT to monitor an XCH4 event on a synoptic scale. We anticipate that the synoptic information of XCH4 from GOSAT data contributes to improve our understanding of regional carbon cycle and the regional flux estimation.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/BG-8-1643-2011", "year": 2011, "title": "Constraining global methane emissions and uptake by ecosystems", "abstract": "Abstract. Natural methane (CH4) emissions from wet ecosystems are an important part of today's global CH4 budget. Climate affects the exchange of CH4 between ecosystems and the atmosphere by influencing CH4 production, oxidation, and transport in the soil. The net CH4 exchange depends on ecosystem hydrology, soil and vegetation characteristics. Here, the LPJ-WHyMe global dynamical vegetation model is used to simulate global net CH4 emissions for different ecosystems: northern peatlands (4590 N), naturally inundated wetlands (60 S45 N), rice agriculture and wet mineral soils. Mineral soils are a potential CH4 sink, but can also be a source with the direction of the net exchange depending on soil moisture content. The geographical and seasonal distributions are evaluated against multi-dimensional atmospheric inversions for 20032005, using two independent four-dimensional variational assimilation systems. The atmospheric inversions are constrained by the atmospheric CH4 observations of the SCIAMACHY satellite instrument and global surface networks. Compared to LPJ-WHyMe the inversions result in a~significant reduction in the emissions from northern peatlands and suggest that LPJ-WHyMe maximum annual emissions peak about one month late. The inversions do not put strong constraints on the division of sources between inundated wetlands and wet mineral soils in the tropics. Based on the inversion results we diagnose model parameters in LPJ-WHyMe and simulate the surface exchange of CH4 over the period 19902008. Over the whole period we infer an increase of global ecosystem CH4 emissions of +1.11 Tg CH4 yr1, not considering potential additional changes in wetland extent. The increase in simulated CH4 emissions is attributed to enhanced soil respiration resulting from the observed rise in land temperature and in atmospheric carbon dioxide that were used as input. The long-term decline of the atmospheric CH4 growth rate from 1990 to 2006 cannot be fully explained with the simulated ecosystem emissions. However, these emissions show an increasing trend of +3.62 Tg CH4 yr1 over 20052008 which can partly explain the renewed increase in atmospheric CH4 concentration during recent years.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/S41558-020-0762-8", "year": 2020, "title": "Remote sensing northern lake methane ebullition", "abstract": "Northern lakes are considered a major source of atmospheric methane (CH4), a potent GHG1,2. However, large uncertainties in their emissions (726 Tg CH4 yr1; ref. 2) arise from challenges in upscaling field data, including fluxes by ebullition (bubbling), the dominant emission pathway2. Remote sensing of ebullition would allow detailed mapping of regional emissions but has hitherto not been developed. Here, we show that lake ebullition can be imaged using synthetic aperture radar remote sensing during ice-cover periods by exploiting the effect of ebullition on the texture of the icewater interface. Applying this method to five Alaska regions and combining spatial remote sensing information with year-round bubble-trap flux measurements, we create ebullition-flux maps for 5,143 Alaskan lakes. Regional lake CH4 emissions, based on satellite remote sensing analyses, were lower compared to previous estimates based on upscaling from individual lakes2,3 and were consistent with independent airborne CH4 observations. Thermokarst lakes formed by thaw of organic-rich permafrost had the highest fluxes, although lake density and lake size distributions also controlled regional emissions. This new remote sensing approach offers an opportunity to improve knowledge about Arctic CH4 fluxes and helps to explain long-standing discrepancies between estimates of CH4 emissions from atmospheric measurements and data upscaled from individual lakes.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1186/S13021-020-00160-5", "year": 2021, "title": "Influence of landscape management practices on urban greenhouse gas budgets", "abstract": "With a lack of United States federal policy to address climate change, cities, the private sector, and universities have shouldered much of the work to reduce carbon dioxide (CO2) and other greenhouse gas emissions. This study aims to determine how landcover characteristics influence the amount of carbon (C) sequestered and respired via biological processes, evaluating the role of land management on the overall C budget of an urban university. Boston University published a comprehensive Climate Action Plan in 2017 with the goal of achieving C neutrality by 2040. In this study, we digitized and discretized each of Boston Universitys three urban campuses into landcover types, with C sequestration and respiration rates measured and scaled to provide a University-wide estimate of biogenic C fluxes within the broader context of total University emissions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/BG-10-2011-2013", "year": 2013, "title": "Multiple observation types reduce uncertainty in Australia's terrestrial carbon and water cycles", "abstract": "Abstract. Information about the carbon cycle potentially constrains the water cycle, and vice versa. This paper explores the utility of multiple observation sets to constrain a land surface model of Australian terrestrial carbon and water cycles, and the resulting mean carbon pools and fluxes, as well as their temporal and spatial variability. Observations include streamflow from 416 gauged catchments, measurements of evapotranspiration (ET) and net ecosystem production (NEP) from 12 eddy-flux sites, litterfall data, and data on carbon pools. By projecting residuals between observations and corresponding predictions onto uncertainty in model predictions at the continental scale, we find that eddy flux measurements provide a significantly tighter constraint on continental net primary production (NPP) than the other data types. Nonetheless, simultaneous constraint by multiple data types is important for mitigating bias from any single type. Four significant results emerging from the multiply-constrained model are that, for the 19902011 period: (i) on the Australian continent, a predominantly semi-arid region, over half the water loss through ET (0.64 0.05) occurs through soil evaporation and bypasses plants entirely; (ii) mean Australian NPP is quantified at 2.2 0.4 (1) Pg C yr1; (iii) annually cyclic (\"grassy\") vegetation and persistent (\"woody\") vegetation account for 0.67 0.14 and 0.33 0.14, respectively, of NPP across Australia; (iv) the average interannual variability of Australia's NEP (0.18 Pg C yr1, 1) is larger than Australia's total anthropogenic greenhouse gas emissions in 2011 (0.149 Pg C equivalent yr1), and is dominated by variability in desert and savanna regions.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1080/16000889.2017.1380497", "year": 2017, "title": "Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-\u00c5lesund, Svalbard from 1996 to 2013", "abstract": "We have conducted systematic observations of the CH4 mole fraction and its carbon isotope ratio (13C) at Ny-Alesund, Svalbard (7855N, 1156E) using air samples collected weekly since 1991 and 1996, respectively. The CH4 mole fraction showed long-term increase until 1999, stagnation between 2000 and 2006, followed by an increase after 2006. On the other hand, 13C showed monotonous increase until 2006 and decrease after 2006. By comparing the rates of change in the CH4 mole fraction and 13C under the assumption that the atmospheric CH4 lifetime is constant, it is suggested that the temporal pause of the CH4 mole fraction observed at Ny-Alesund is attributed to reductions of CH4 release from the microbial and fossil fuel sectors. On the other hand, the increase in CH4 after 2006 could be ascribed to an increase in microbial CH4 release. The CH4 and 13C data presented in this paper would be useful for clarifying their temporal variations in the Arctic atmosphere, as well as providing additional constraints on the global CH4 budget.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/AMT-11-2653-2018", "year": 2018, "title": "How well can global chemistry models calculate the reactivity of short-lived greenhouse gases in the remote troposphere, knowing the chemical composition", "abstract": "Abstract. We develop a new protocol for merging in situ measurements with 3-D model simulations of atmospheric chemistry with the goal of integrating these data to identify the most reactive air parcels in terms of tropospheric production and loss of the greenhouse gases ozone and methane. Presupposing that we can accurately measure atmospheric composition, we examine whether models constrained by such measurements agree on the chemical budgets for ozone and methane. In applying our technique to a synthetic data stream of 14 880 parcels along 180 W, we are able to isolate the performance of the photochemical modules operating within their global chemistry-climate and chemistry-transport models, removing the effects of modules controlling tracer transport, emissions, and scavenging. Differences in reactivity across models are driven only by the chemical mechanism and the diurnal cycle of photolysis rates, which are driven in turn by temperature, water vapor, solar zenith angle, clouds, and possibly aerosols and overhead ozone, which are calculated in each model. We evaluate six global models and identify their differences and similarities in simulating the chemistry through a range of innovative diagnostics. All models agree that the more highly reactive parcels dominate the chemistry (e.g., the hottest 10 % of parcels control 2530 % of the total reactivities), but do not fully agree on which parcels comprise the top 10 %. Distinct differences in specific features occur, including the spatial regions of maximum ozone production and methane loss, as well as in the relationship between photolysis and these reactivities. Unique, possibly aberrant, features are identified for each model, providing a benchmark for photochemical module development. Among the six models tested here, three are almost indistinguishable based on the inherent variability caused by clouds, and thus we identify four, effectively distinct, chemical models. Based on this work, we suggest that water vapor differences in model simulations of past and future atmospheres may be a cause of the different evolution of tropospheric O3 and CH4, and lead to different chemistry-climate feedbacks across the models.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ESSD-10-653-2018", "year": 2018, "title": "Vista-LA: Mapping methane-emitting infrastructure in the Los Angeles megacity", "abstract": "Abstract. Methane (CH4) is a potent greenhouse gas (GHG) and a critical target of climate mitigation efforts. However, actionable emission reduction efforts are complicated by large uncertainties in the methane budget on relevant scales. Here, we present Vista, a Geographic Information System (GIS)-based approach to map potential methane emissions sources in the South Coast Air Basin (SoCAB) that encompasses Los Angeles, an area with a dense, complex mixture of methane sources. The goal of this work is to provide a database that, together with atmospheric observations, improves methane emissions estimates in urban areas with complex infrastructure. We aggregated methane source location information into three sectors (energy, agriculture, and waste) following the frameworks used by the State of California GHG Inventory and the Intergovernmental Panel on Climate Change (IPCC) Guidelines for GHG Reporting. Geospatial modeling was applied to publicly available datasets to precisely geolocate facilities and infrastructure comprising major anthropogenic methane source sectors. The final database, Vista-Los Angeles (Vista-LA), is presented as maps of infrastructure known or expected to emit CH4. Vista-LA contains over 33 000 features concentrated on < 1 % of land area in the region. Currently, Vista-LA is used as a planning and analysis tool for atmospheric measurement surveys of methane sources, particularly for airborne remote sensing, and methane hotspot detection using regional observations. This study represents a first step towards developing an accurate, spatially resolved methane flux estimate for point sources in SoCAB, with the potential to address discrepancies between bottomup and topdown methane emissions accounting in this region. The Vista-LA datasets and associated metadata are available from the Oak Ridge National Laboratory Distributed Active Archive Center for Biogeochemical Dynamics (ORNL DAAC; https://doi.org/10.3334/ORNLDAAC/1525).", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5268/IW-4.4.746", "year": 2014, "title": "Carbon dioxide emissions from dry watercourses", "abstract": "Temporary watercourses that naturally cease to flow and run dry comprise a notable fraction of the worlds river networks, yet estimates of global carbon dioxide (CO2) emissions from watercourses do not consider emissions from these systems when they are dry. Using data from a sampling campaign in a Mediterranean river during the summer drought period, we demonstrate that the CO2 efflux from dry watercourses can be substantial, comparable to that from adjacent terrestrial soils and higher than from running or stagnant waters. With an up-scaling approach, we show that including emissions from dry watercourses could increase the estimate of CO2 emissions from watercourses in our study region by 0.615%. Moreover, our results tentatively illustrate that emissions from dry watercourses could be especially important in arid regions, increasing the estimate of global CO2 emissions from watercourses by 0.49%. Albeit relatively small, the contribution of dry watercourses could help to constrain the highly uncertain magnitude of the land carbon sink. We foresee that in many areas of the world, the expected increase in the extent of temporary watercourses associated with future global change will increase the relevance of CO2 emissions from dry watercourses.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1186/S13021-020-00157-0", "year": 2020, "title": "Informing urban climate planning with high resolution data: the Hestia fossil fuel CO2 emissions for Baltimore, Maryland", "abstract": "Cities contribute more than 70% of global anthropogenic carbon dioxide (CO2) emissions and are leading the effort to reduce greenhouse gas (GHG) emissions through sustainable planning and development. However, urban greenhouse gas mitigation often relies on self-reported emissions estimates that may be incomplete and unverifiable via atmospheric monitoring of GHGs. We present the Hestia Scope 1 fossil fuel CO2 (FFCO2) emissions for the city of Baltimore, Marylanda gridded annual and hourly emissions data product for 2010 through 2015 (Hestia-Baltimore v1.6). We also compare the Hestia-Baltimore emissions to overlapping Scope 1 FFCO2 emissions in Baltimores self-reported inventory for 2014.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1073/PNAS.0913658107", "year": 2010, "title": "A high-resolution assessment on global nitrogen flows in cropland", "abstract": "Crop production is the single largest cause of human alteration of the global nitrogen cycle. We present a comprehensive assessment of global nitrogen flows in cropland for the year 2000 with a spatial resolution of 5 arc-minutes. We calculated a total nitrogen input (IN) of 136.60 trillion grams (Tg) of N per year, of which almost half is contributed by mineral nitrogen fertilizers, and a total nitrogen output (OUT) of 148.14 Tg of N per year, of which 55% is uptake by harvested crops and crop residues. We present high-resolution maps quantifying the spatial distribution of nitrogen IN and OUT flows, soil nitrogen balance, and surface nitrogen balance. The high-resolution data are aggregated at the national level on a per capita basis to assess nitrogen stress levels. The results show that almost 80% of African countries are confronted with nitrogen scarcity or nitrogen stress problems, which, along with poverty, cause food insecurity and malnutrition. The assessment also shows a global average nitrogen recovery rate of 59%, indicating that nearly two-fifths of nitrogen inputs are lost in ecosystems. More effective management of nitrogen is essential to reduce the deleterious environmental consequences.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/B978-0-12-814952-2.00004-6", "year": 2022, "title": "Ocean systems", "abstract": "The ocean comprises ~71% of the Earths surface area and is in constant interaction with the atmosphere above and the land surface at the coastal interface, allowing a continuous exchange of greenhouse gases (GHGs) between the spheres. The ocean plays an important role in absorbing and storing carbon dioxide (CO2) from fossil fuel combustion, land-use change, and cement production. Since the industrial revolution, the ocean has stored ~31% of human emitted CO2 adding to a total storage of anthropogenic CO2 of 15220PgC (PgC=Petagrams of carbon) from 1850 to 2007 and is currently removing about 2.60.6PgC of excess CO2 every year from the atmosphere. On longer timescales (i.e., centuries to millennia), the ocean carbon sink acts as a primary regulator of the Earths climate. While the ocean carbon sink mitigates climate change, absorption of anthropogenic CO2 leads to ocean acidification with potentially harmful effects for marine ecosystems. The ocean also contributes to the cycles of other greenhouse gases. Specifically, it is a weak source of methane. The contribution of the ocean to the net global methane budget, however, is substantially smaller than the oceanic uptake of CO2. The ocean was a net source of methane (CH4) to the atmosphere of ~13TgCH4year1 (TgCH4=Teragrams of CH4) with a possible range of 922TgCH4year1 over the period 200020. Hence, the methane fluxes from the ocean to the atmosphere are an order of magnitude smaller than the anthropogenic emissions over the same period. Likewise, the ocean comprises a natural source of nitrous oxide (N2O) of ~3.4TgNyear1between 2007 and 2016, although with a substantial possible range between 2.5 and 4.3TgNyear1.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S00027-019-0665-9", "year": 2019, "title": "Carbon dioxide emission from drawdown areas of a Brazilian reservoir is linked to surrounding land cover", "abstract": "Reservoir sediments exposed to air due to water level fluctuations are strong sources of atmospheric carbon dioxide (CO2). The spatial variability of CO2 fluxes from these drawdown areas are still poorly understood. In a reservoir in southeastern Brazil, we investigated whether CO2 emissions from drawdown areas vary as a function of neighboring land cover types and assessed the magnitude of CO2 fluxes from drawdown areas in relation to nearby water surface. Exposed sediments near forestland (average = 2733 mg C m2 day1) emitted more CO2 than exposed sediments near grassland (average = 1261 mg C m2 day1), congruent with a difference in organic matter content between areas adjacent to forestland (average = 12.2%) and grassland (average = 10.9%). Moisture also had a significant effect on CO2 emission, with dry exposed sediments (average water content: 13.7%) emitting on average 2.5 times more CO2 than wet exposed sediments (average water content: 23.5%). We carried out a systematic comparison with data from the literature, which indicates that CO2 efflux from drawdown areas globally is about an order of magnitude higher than CO2 efflux from adjacent water surfaces, and within the range of CO2 efflux from terrestrial soils. Our findings suggest that emissions from exposed sediments may vary substantially in space, possibly related to organic matter supply from uphill vegetation, and that drawdown areas play a disproportionately important role in total reservoir CO2 emissions with respect to the area they cover.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/978-981-16-5493-0_5", "year": 2021, "title": "Water Security and Climate Change: Hydropower Reservoir Greenhouse Gas Emissions", "abstract": "Water storage is a driver for economic growth and often mentioned as a proxy for water securityWatersecurity. Hydropower storage projects deliver multiple benefits contributing to water and energy security; however, the reservoir creation raises concerns about greenhouse gas (GHG) emissions and puts in doubt how clean hydropower generation is. As storage becomes more relevant under climate changeClimatechange, adequate assessment is necessary to ensure projects sustainability. This study quantifies hydropower global median lifecycle greenhouse emissions at 23 gCO2e/kWh using the G-res Tool to estimate the net emission for 480 hydropower storage projects. This result is aligned with the IPCCIntergovernmental Panel on Climate Change (IPCC) estimates.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.FORECO.2015.03.040", "year": 2015, "title": "Aboveground live carbon stock changes of California wildland ecosystems, 2001\u20132010", "abstract": "The balance between ecosystem emissions of carbon to the atmosphere and removals from the atmosphere indicates whether ecosystems are exacerbating or reducing climate change. Forest ecosystems in the State of California, USA, contain carbon that reaches the highest densities (mass per unit area) in the world, but it has been unresolved whether California ecosystems currently comprise a net sink or source of carbon. The California Global Warming Solutions Act of 2006 established greenhouse gas reduction targets for fossil fuel-burning sectors and ecosystems, underscoring the importance of tracking ecosystem carbon. Here, we conduct statewide spatial inventories of the aboveground live carbon stocks of forests and other terrestrial ecosystems of California, excluding agricultural and urban areas. We analyzed biomass data from field measurements of the Forest Inventory and Analysis program, published biomass information and remote sensing data on non-forest vegetation, and spatial distributions of vegetation types, height, and fractional cover derived by the Landfire program from Landsat remote sensing at 30m spatial resolution. We conducted Monte Carlo analyses of the uncertainty of carbon stock change estimates from errors in tree biomass estimates, remote sensing, and estimates of the carbon fraction of biomass. The carbon stock in aboveground biomass was 850230 Tg (mean95% confidence interval) in 2010. We found a net aboveground live carbon stock change of 6915 Tg from 2001 to 2010, a rate of change of 0.80.2%y1. Due to slow decay of some dead wood, all of the live carbon stock change does not immediately generate emissions. Wildfires on 6% of the state analysis area produced two-thirds of the live carbon stock loss. This suggests that increased tree densities from a century of fire suppression have allowed the accumulation of fuel for carbon losses in recent wildfires. Remote sensing errors in vegetation classification accounted for most of the uncertainty in the carbon stock change estimates. Improvements are also needed to track spatial patterns of growth and dead wood. Our results establish the beginning of a time series for the state greenhouse gas inventory and provide information on the role of forest conservation and management in California in mitigating global climate change.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/S41597-022-01467-3", "year": 2022, "title": "A multi-city urban atmospheric greenhouse gas measurement data synthesis", "abstract": "Urban regions emit a large fraction of anthropogenic emissions of greenhouse gases (GHG) such as carbon dioxide (CO2) and methane (CH4) that contribute to modern-day climate change. As such, a growing number of urban policymakers and stakeholders are adopting emission reduction targets and implementing policies to reach those targets. Over the past two decades research teams have established urban GHG monitoring networks to determine how much, where, and why a particular city emits GHGs, and to track changes in emissions over time. Coordination among these efforts has been limited, restricting the scope of analyses and insights. Here we present a harmonized data set synthesizing urban GHG observations from cities with monitoring networks across North America that will facilitate cross-city analyses and address scientific questions that are difficult to address in isolation.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/GCB.15290", "year": 2020, "title": "Increased greenhouse gas emissions intensity of major croplands in China: Implications for food security and climate change mitigation", "abstract": "AbstractBalancing crop production and greenhouse gas (GHG) emissions from agriculture soil requires a better understanding and quantification of crop GHG emissions intensity, a measure of GHG emissions per unit crop production. Here we conduct a stateoftheart estimate of the spatialtemporal variability of GHG emissions intensities for wheat, maize, and rice in China from 1949 to 2012 using an improved agricultural ecosystem model (Dynamic Land Ecosystem ModelAgriculture Version 2.0) and metaanalysis covering 172 fieldGHG emissions experiments. The results show that the GHG emissions intensities of these croplands from 1949 to 2012, on average, were 0.101.31 kg CO2eq/kg, with a significant increase rate of 1.843.58 103 kg CO2eq kg1 year1. Nitrogen fertilizer was the dominant factor contributing to the increase in GHG emissions intensity in northern China and increased its impact in southern China in the 2000s. Increasing GHG emissions intensity implies that excessive fertilizer failed to markedly stimulate crop yield increase in China but still exacerbated soil GHG emissions. This study found that overfertilization of more than 60% was mainly located in the winter wheatsummer maize rotation systems in the North China Plain, the winter wheatrice rotation systems in the middle and lower reaches of the Yangtze River and southwest China, and most of the double rice systems in the South. Our simulations suggest that roughly a onethird reduction in the current N fertilizer application level over these overfertilization regions would not significantly influence crop yield but decrease soil GHG emissions by 29.60%32.50% and GHG emissions intensity by 0.130.25 kg CO2eq/kg. This reduction is about 29% and 5% of total agricultural soil GHG emissions in China and the world, respectively. This study suggests that improving nitrogen use efficiency would be an effective strategy to mitigate GHG emissions and sustain China's food security.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ESSD-12-563-2020", "year": 2020, "title": "A global gridded (0.1\u00d7 0.1) inventory of methane emissions from oil, gas, and coal exploitation based on national reports to the United Nations Framework \u2026", "abstract": "Abstract. Individual countries report national emissions of methane, a potent greenhouse gas, in accordance with the United Nations Framework Convention on Climate Change (UNFCCC). We present a global inventory of methane emissions from oil, gas, and coal exploitation that spatially allocates the national emissions reported to the UNFCCC (Scarpelli et al., 2019). Our inventory is at 0.10.1 resolution and resolves the subsectors of oil and gas exploitation, from upstream to downstream, and the different emission processes (leakage, venting, flaring). Global emissions for 2016 are 41.5 Tg a1 for oil, 24.4 Tg a1 for gas, and 31.3 Tg a1 for coal. An array of databases is used to spatially allocate national emissions to infrastructure, including wells, pipelines, oil refineries, gas processing plants, gas compressor stations, gas storage facilities, and coal mines. Gridded error estimates are provided in normal and lognormal forms based on emission factor uncertainties from the IPCC. Our inventory shows large differences with the EDGAR v4.3.2 global gridded inventory both at the national scale and in finer-scale spatial allocation. It shows good agreement with the gridded version of the United Kingdom's National Atmospheric Emissions Inventory (NAEI). There are significant errors on the 0.10.1 grid associated with the location and magnitude of large point sources, but these are smoothed out when averaging the inventory over a coarser grid. Use of our inventory as prior estimate in inverse analyses of atmospheric methane observations allows investigation of individual subsector contributions and can serve policy needs by evaluating the national emissions totals reported to the UNFCCC. Gridded data sets can be accessed at https://doi.org/10.7910/DVN/HH4EUM (Scarpelli et al., 2019).", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2021JG006635", "year": 2022, "title": "The Importance of Lake Emergent Aquatic Vegetation for Estimating ArcticBoreal Methane Emissions", "abstract": "Areas of lakes that support emergent aquatic vegetation emit disproportionately more methane than open water but are under-represented in upscaled estimates of lake greenhouse gas emissions. These shallow areas are typically less than \u223c1.5 m deep and can be detected with synthetic aperture radar (SAR). To assess the importance of lake emergent vegetation (LEV) zones to landscape-scale methane emissions, we combine airborne SAR mapping with field measurements of vegetated and open-water methane flux. First, we use Uninhabited Aerial Vehicle SAR data from the NASA Arctic-Boreal Vulnerability Experiment to map LEV in 4,572 lakes across four Arctic-boreal study areas and find it comprises \u223c16% of lake area, exceeding previous estimates, and exhibiting strong regional differences (averaging 59 [50-68]%, 22 [20-25]%, 1.0 [0.8-1.2]%, and 7.0 [5.0-12]% of lake areas in the Peace-Athabasca Delta, Yukon Flats, and northern and southern Canadian Shield, respectively). Next, we account for these vegetated areas through a simple upscaling exercise using paired methane fluxes from regions of open water and LEV. After excluding vegetated areas that could be accounted for as wetlands, we find that inclusion of LEV increases overall lake emissions by 21 [18-25]% relative to estimates that do not differentiate lake zones. While LEV zones are proportionately greater in small lakes, this relationship is weak and varies regionally, underscoring the need for methane-relevant remote sensing measurements of lake zones and a consistent criterion for distinguishing wetlands. Finally, Arctic-boreal lake methane upscaling estimates can be improved with more measurements from all lake zones.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S41742-022-00501-X", "year": 2022, "title": "Decadal Changes in Atmospheric Methane Emissions in the Eastern Himalayan Region: Source Apportionment and Impact Assessment", "abstract": "Methane (CH4), the second-largest greenhouse gas in terms of radiative forcing, is on the rise in the Eastern Himalayan region (EHR), as indicated by multiple datasets (CAMS ~ 0.087 Tg Yr1, EDGAR v4.3.2 ~ 0.11 Tg Yr1, and RCP8.5 ~ 0.16 Tg Yr1). We found that the CH4 trend over the EHR is stronger than the global trend due to increased emissions from anthropogenic sources. From 1990 to 2016, CH4 emissions from anthropogenic activities and wetlands increased by 20% and 10% over the EHR. The land-use land-cover (LULC) change reveals a loss of ~ 0.42% of forest and an increase of 0.018% of urban built-up, 0.098% total wetland, and 0.033% of water-bodies coverage from 2001 to 2018. Future projections show a twofold (32.7 Tg CH4 Yr1) increase in CH4 emissions by 2050 and up to a threefold (~ 48.2 Tg CH4 Yr1) by the year 2100 from the base year level (14.6 Tg CH4 Yr1) in 2000. Ambient concentrations of CH4 measured in Dibrugarh and the CAMS reanalysis data set from March 2014 to February 2015 show the maximum in December (~ 4485 and ~ 1981 ppb, respectively), while the minimum concentrations in July (~ 1155 ppb and ~ 976 ppb). The calculated global/EHR RF due to the CH4 for 20062100 is higher (0.0093 Wm2 Yr1/0.0095 Wm2 Yr1) than the historical (0.0038 Wm2 Yr1/0.0037 Wm2 Yr1) during 18512005. The resultant land surface temperature increase induced solely by CH4 is higher over the EHR (~ 0.0062 C Yr1) than the global (~ 0.0036 C Yr1).", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-21-951-2021", "year": 2021, "title": "Aircraft-based inversions quantify the importance of wetlands and livestock for Upper Midwest methane emissions", "abstract": "Abstract. We apply airborne measurements across three seasons (summer, winter and spring 20172018) in a multi-inversion framework to quantify methane emissions from the US Corn Belt and Upper Midwest, a key agricultural and wetland source region. Combing our seasonal results with prior fall values we find that wetlands are the largest regional methane source (32 %, 20 [1623] Gg/d), while livestock (enteric/manure; 25 %, 15 [1417] Gg/d) are the largest anthropogenic source. Natural gas/petroleum, waste/landfills, and coal mines collectively make up the remainder. Optimized fluxes improve model agreement with independent datasets within and beyond the study timeframe. Inversions reveal coherent and seasonally dependent spatial errors in the WetCHARTs ensemble mean wetland emissions, with an underestimate for the Prairie Pothole region but an overestimate for Great Lakes coastal wetlands. Wetland extent and emission temperature dependence have the largest influence on prediction accuracy; better representation of coupled soil temperaturehydrology effects is therefore needed. Our optimized regional livestock emissions agree well with the Gridded EPA estimates during spring (to within 7 %) but are 25 % higher during summer and winter. Spatial analysis further shows good top-down and bottom-up agreement for beef facilities (with mainly enteric emissions) but larger ( 30 %) seasonal discrepancies for dairies and hog farms (with > 40 % manure emissions). Findings thus support bottom-up enteric emission estimates but suggest errors for manure; we propose that the latter reflects inadequate treatment of management factors including field application. Overall, our results confirm the importance of intensive animal agriculture for regional methane emissions, implying substantial mitigation opportunities through improved management.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1073/PNAS.1618567114", "year": 2017, "title": "Carbon dioxide sources from Alaska driven by increasing early winter respiration from Arctic tundra", "abstract": "Significance\r\n \r\n Rising arctic temperatures could mobilize reservoirs of soil organic carbon trapped in permafrost. We present the first quantitative evidence for large, regional-scale early winter respiration flux, which more than offsets carbon uptake in summer in the Arctic. Data from the National Oceanic and Atmospheric Administrations Barrow station indicate that October through December emissions of CO\r\n 2\r\n from surrounding tundra increased by 73% since 1975, supporting the view that rising temperatures have made Arctic ecosystems a net source of CO\r\n 2\r\n . It has been known for over 50 y that tundra soils remain unfrozen and biologically active in early winter, yet many Earth System Models do not correctly represent this phenomenon or the associated CO\r\n 2\r\n emissions, and hence they underestimate current, and likely future, CO\r\n 2\r\n emissions under climate change.\r\n \r\n , \r\n \r\n High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO\r\n 2\r\n ) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO\r\n 2\r\n with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO\r\n 2\r\n fluxes across Alaska during 20122014. We find that tundra ecosystems were a net source of CO\r\n 2\r\n to the atmosphere annually, with especially high rates of respiration during early winter (October through December). Long-term records at Barrow, AK, suggest that CO\r\n 2\r\n emission rates from North Slope tundra have increased during the October through December period by 73% 11% since 1975, and are correlated with rising summer temperatures. Together, these results imply increasing early winter respiration and net annual emission of CO\r\n 2\r\n in Alaska, in response to climate warming. Our results provide evidence that the decadal-scale increase in the amplitude of the CO\r\n 2\r\n seasonal cycle may be linked with increasing biogenic emissions in the Arctic, following the growing season. Early winter respiration was not well simulated by the Earth System Models used to forecast future carbon fluxes in recent climate assessments. Therefore, these assessments may underestimate the carbon release from Arctic soils in response to a warming climate.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/BTP.12061", "year": 2013, "title": "Tree Species Effects on Soil Properties and Greenhouse Gas Fluxes in", "abstract": "Tropical plantations are considered a viable option to sequester carbon on abandoned agricultural lands, but implications of tree species selection for overall greenhouse gas budgets on plantations have been little studied. During three wet seasons, we investigated the influence of nine tree species on soil pH, temperature (ST), bulk density (BD), moisture content water filled pore space (WFPS), and greenhouse gas fluxes in diverse forest sites and monoculture plantation plots. All sites were on clay\u2011rich soils of the Barreiras formation, in east\u2011central Amaz\u00f4nia, Brazil. We found that ST and BD were 0.6\u00b0C and 0.2 g/cm3 higher in the plantation relative to the forest, and soil CH4, CO,2 and N2O fluxes were, respectively, 38, 12, 62, percent lower in the plantation. Tree growth rates were highly variable on the plantation, with the mean comparable to the forest sites. Tree species identity mattered (P < 0.01) for all soil properties and gas fluxes on the plantation, but only for pH, BD, WFPS, and N2O fluxes in the forest. The species rank order of pH and N2O fluxes in the forest, however, were unlike the plantation. Tree growth rates were a strong predictor for soil WFPS, and together with location, they also explained 75 percent of the mean N2O flux variation. Our study indicates that: (1) tree species influence soil processes; and (2) high tree growth and low soil gas emissions imply a reduced climate forcing effect from plantations, especially when planted with fast\u2011growing legume species on abandoned farmland.ResumoPlanta\u00e7\u00f5es tropicais s\u00e3o considerados uma op\u00e7\u00e3o vi\u00e1vel para o sequestro de carbono em terras agr\u00edcolas abandonadas, mas implica\u00e7\u00f5es da sele\u00e7\u00e3o de esp\u00e9cies de \u00e1rvores para os or\u00e7amentos globais de gases de efeito estufa nestas planta\u00e7\u00f5es t\u00eam sido pouco estudados. Durante tr\u00eas esta\u00e7\u00f5es \u00famidas investigou\u2011se a influ\u00eancia de nove esp\u00e9cies de \u00e1rvores no pH do solo, temperatura (ST), densidade (BD), teor de umidade (WFPS) e fluxos de gases de efeito estufa em tres \u00e1reas de floresta e \u00e1reas com monocultura. Todos os sites foram em solos muito argiloso da forma\u00e7\u00e3o Barreiras, localizadas no centro\u2011oeste da Amaz\u00f4nia, Brasil. Foi encontrado que ST e BD foram de 0,6 \u00ba C e 0,2 g/cm3 maior no plantio em compara\u00e7\u00e3o \u00e0 floresta, e que os fluxos do solo de CH4, CO2 e N2O foram, respectivamente, 38, 12, 62 por cento menores no planta\u00e7\u00e3o. O crescimento das \u00e1rvores foram altamente vari\u00e1vel no planta\u00e7\u00e3o, com a m\u00e9dia compar\u00e1vel \u00e0s \u00e1reas florestais. A identidade das esp\u00e9cies de \u00e0rvores importava (P < 0,01) para todas as propriedades do solo e fluxos de gases na planta\u00e7\u00e3o, mas apenas para pH, BD, WFPS e os fluxos de N2O na floresta. No entanto, a ordem de classifica\u00e7\u00e3o de esp\u00e9cies de pH e os fluxos de N2O na floresta eram diferentes da planta\u00e7\u00e3o. As taxas de crescimento das \u00e1rvores preditaram bem a WFPS do solo e, junto com a localiza\u00e7\u00e3o, tamb\u00e9m explicou 75 por cento da varia\u00e7\u00e3o das m\u00e9dias dos fluxos de N2O. Nossa pesquisa indica que: 1) as esp\u00e9cies de \u00e1rvores influencaram os processos do solo, e 2) o crescimento r\u00e1pido das \u00e1rvores e emiss\u00f5es de gases do solo baixas implicaram um reduzido efeito for\u00e7ando clima de planta\u00e7\u00f5es, em principalmente quando plantada com esp\u00e9cies leguminosas de crescimento r\u00e1pido em terras agr\u00edcolas abandonadas.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2019GL085707", "year": 2020, "title": "Airborne mapping reveals emergent power law of arctic methane emissions", "abstract": "Methane (CH4) emissions from thawing permafrost amplify a climate warming feedback. However, upscaling of site-level CH4 observations across diverse Arctic landscapes remains highly uncertain, compromising accuracy of current pan-Arctic CH4 budgets and confidence in model forecasts. We report a 30,000-km2 survey at 25-m2 resolution (~1 billion observations) of CH4 hotspot patterns across Alaska and northwestern Canada using airborne imaging spectroscopy. Hotspots covered 0.2% of the surveyed area, concentrated in the wetland-upland ecotone, and followed a two-component power law as a function of distance from standing water. Hotspots decreased sharply over the first 40 m from standing water (y = 0.21\u00d7-0.649, R2 = 0.97), mirroring in situ flux observations. Beyond 40 m, CH4 hotspots diminished gradually over hundreds of meters (y = 0.004\u00d7-0.164, R2 = 0.99). This emergent property quantifies the distribution of strong methanogenic zones from site to regional scales, vastly improving metrics for scaling ground-based CH4 inventories and validation of land models.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2010JG001300", "year": 2011, "title": "Marine methane cycle simulations for the period of early global warming", "abstract": "Geochemical environments, fates, and effects are modeled for methane released into seawater by the decomposition of climate-sensitive clathrates. A contemporary global background cycle is first constructed, within the framework of the Parallel Ocean Program. Input from organics in the upper thermocline is related to oxygen levels, and microbial consumption is parameterized from available rate measurements. Seepage into bottom layers is then superimposed, representing typical seabed fluid flow. The resulting CH4 distribution is validated against surface saturation ratios, vertical sections, and slope plume studies. Injections of clathrate-derived methane are explored by distributing a small number of point sources around the Arctic continental shelf, where stocks are extensive and susceptible to instability during the first few decades of global warming. Isolated bottom cells are assigned dissolved gas fluxes from porous-media simulation. Given the present bulk removal pattern, methane does not penetrate far from emission sites. Accumulated effects, however, spread to the regional scale following the modeled current system. Both hypoxification and acidification are documented. Sensitivity studies illustrate a potential for material restrictions to broaden the perturbations, since methanotrophic consumers require nutrients and trace metals. When such factors are considered, methane buildup within the Arctic basin is enhanced. However, freshened polar surface waters act as a barrier to atmospheric transfer, diverting products into the deep return flow. Uncertainties in the logic and calculations are enumerated including those inherent in high-latitude clathrate abundance, buoyant effluent rise through the column, representation of the general circulation, and bacterial growth kinetics.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-17-5407-2017", "year": 2017, "title": "Lower-tropospheric CO2 from near-infrared ACOS-GOSAT observations", "abstract": "Abstract. We present two new products from near-infrared Greenhouse Gases Observing Satellite (GOSAT) observations: lowermost tropospheric (LMT, from 0 to 2.5 km) and upper troposphericstratospheric (U, above 2.5 km) carbon dioxide partial column mixing ratios. We compare these new products to aircraft profiles and remote surface flask measurements and find that the seasonal and year-to-year variations in the new partial column mixing ratios significantly improve upon the Atmospheric CO2 Observations from Space (ACOS) and GOSAT (ACOS-GOSAT) initial guess and/or a priori, with distinct patterns in the LMT and U seasonal cycles that match validation data. For land monthly averages, we find errors of 1.9, 0.7, and 0.8 ppm for retrieved GOSAT LMT, U, and XCO2; for ocean monthly averages, we find errors of 0.7, 0.5, and 0.5 ppm for retrieved GOSAT LMT, U, and XCO2. In the southern hemispheric biomass burning season, the new partial columns show similar patterns to MODIS fire maps and MOPITT multispectral CO for both vertical levels, despite a flat ACOS-GOSAT prior, and a COCO2 emission factor comparable to published values. The difference of LMT and U, useful for evaluation of model transport error, has also been validated with a monthly average error of 0.8 (1.4) ppm for ocean (land). LMT is more locally influenced than U, meaning that local fluxes can now be better separated from CO2 transported from far away.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.ATMOSENV.2021.118239", "year": 2021, "title": "Greenhouse gas fluxes from Alaska's North Slope inferred from the Airborne Carbon Measurements campaign (ACME-V)", "abstract": "Northern high latitudes are likely to be heavily impacted by climate change, changes that will undoubtedly alter carbon cycling across these regions. An understanding of both the magnitude and drivers of current CO2 and CH4 fluxes are a prerequisite for making robust projections of future changes. In this study, we use observations from the recent Airborne Carbon Measurements (ACME-V) aircraft campaign to estimate the magnitude and environmental predictors CO2 and CH4 fluxes in Alaska. ACME-V consisted of 38 flights across the North Slope between late May and mid-September 2015, making it the most detailed airborne survey of northern Alaska to date. These data, combined with a geostatistical inverse model, provide a unique lens into fluxes across the region. Using this approach, we estimate a large CO2 flux to the atmosphere from the North Slope of Alaska in early summer that is counterbalanced by CO2 uptake in late summer; this balance between early season respiration and late-summer photosynthesis drives the total summer CO2 flux across northern Alaska during the study period. We further compare our results to process-based flux estimates (the Terrestrial Model Intercomparison Project, MsTMIP and the Wetland and Wetland CH4 Inter-comparison of Models Project, WETCHIMP) and several recent studies of the same spatial domain. We observe a similarity in CO2 flux totals between MsTMIP suite of models and our study (June 20150.86 0.57 vs 0.96, July 2015 MsTMIP 1.01 0.00 vs 0.14 and August 2915 MsTMIP 0.73 0.29 vs 0.50 mol m2 s1, MsTMIP and our study, respectively, averaged across the North Slope). However, we find significantly higher CH4 fluxes from the North Slope than any of the WETCHIMP models. Specifically, we estimate total CH4 fluxes from the North Slope of Alaska of +0.64 0.13 Tg (95% confidence), during June through August 2015 while the WETCHIMP model estimates range from 0.004 to 0.1 Tg, depending upon the model. Furthermore, the contribution of the North Slope tundra to the overall Alaskan CH4 fluxes during the entire period was ~27%, compared to 3% in state-of-the-art process-based models.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/AMT-14-7277-2021", "year": 2021, "title": "Neural-network-based estimation of regional-scale anthropogenic CO2 emissions using an Orbiting Carbon Observatory-2 (OCO-2) dataset over East and \u2026", "abstract": "Abstract. Atmospheric carbon dioxide (CO2) is the most significant greenhouse gas, and its concentration is continuously increasing, mainly as a consequence of anthropogenic activities. Accurate quantification of CO2 is critical for addressing the global challenge of climate change and for designing mitigation strategies aimed at stabilizing CO2 emissions. Satellites provide the most effective way to monitor the concentration of CO2 in the atmosphere. In this study, we utilized the concentration of the column-averaged dry-air mole fraction of CO2, i.e., XCO2 retrieved from a CO2 monitoring satellite, the Orbiting Carbon Observatory-2 (OCO-2), and the net primary productivity (NPP) provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the anthropogenic CO2 emissions using the Generalized Regression Neural Network (GRNN) over East and West Asia. OCO-2 XCO2, MODIS NPP, and the Open-Data Inventory for Anthropogenic Carbon dioxide (ODIAC) CO2 emission datasets for a period of 5 years (20152019) were used in this study. The annual XCO2 anomalies were calculated from the OCO-2 retrievals for each year to remove the larger background CO2 concentrations and seasonal variability. The XCO2 anomaly, NPP, and ODIAC emission datasets from 2015 to 2018 were then used to train the GRNN model, and, finally, the anthropogenic CO2 emissions were estimated for 2019 based on the NPP and XCO2 anomalies derived for the same year. The estimated and the ODIAC CO2 emissions were compared, and the results showed good agreement in terms of spatial distribution. The CO2 emissions were estimated separately over East and West Asia. In addition, correlations between the ODIAC emissions and XCO2 anomalies were also determined separately for East and West Asia, and East Asia exhibited relatively better results. The results showed that satellite-based XCO2 retrievals can be used to estimate the regional-scale anthropogenic CO2 emissions, and the accuracy of the results can be enhanced by further improvement of the GRNN model with the addition of more CO2 emission and concentration datasets.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-15-9765-2015", "year": 2015, "title": "Sensitivity of the recent methane budget to LMDz sub-grid-scale physical parameterizations", "abstract": "Abstract. With the densification of surface observing networks and the development of remote sensing of greenhouse gases from space, estimations of methane (CH4) sources and sinks by inverse modeling are gaining additional constraining data but facing new challenges. The chemical transport model (CTM) linking the flux space to methane mixing ratio space must be able to represent these different types of atmospheric constraints for providing consistent flux estimations. Here we quantify the impact of sub-grid-scale physical parameterization errors on the global methane budget inferred by inverse modeling. We use the same inversion setup but different physical parameterizations within one CTM. Two different schemes for vertical diffusion, two others for deep convection, and one additional for thermals in the planetary boundary layer (PBL) are tested. Different atmospheric methane data sets are used as constraints (surface observations or satellite retrievals). At the global scale, methane emissions differ, on average, from 4.1 Tg CH4 per year due to the use of different sub-grid-scale parameterizations. Inversions using satellite total-column mixing ratios retrieved by GOSAT are less impacted, at the global scale, by errors in physical parameterizations. Focusing on large-scale atmospheric transport, we show that inversions using the deep convection scheme of Emanuel (1991) derive smaller interhemispheric gradients in methane emissions, indicating a slower interhemispheric exchange. At regional scale, the use of different sub-grid-scale parameterizations induces uncertainties ranging from 1.2 % (2.7 %) to 9.4 % (14.2 %) of methane emissions when using only surface measurements from a background (or an extended) surface network. Moreover, spatial distribution of methane emissions at regional scale can be very different, depending on both the physical parameterizations used for the modeling of the atmospheric transport and the observation data sets used to constrain the inverse system. When using only satellite data from GOSAT, we show that the small biases found in inversions using a coarser version of the transport model are actually masking a poor representation of the stratospheretroposphere methane gradient in the model. Improving the stratospheretroposphere gradient reveals a larger bias in GOSAT CH4 satellite data, which largely amplifies inconsistencies between the surface and satellite inversions. A simple bias correction is proposed. The results of this work provide the level of confidence one can have for recent methane inversions relative to physical parameterizations included in CTMs.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2020JD032815", "year": 2020, "title": "Evaluating Cropland N2O Emissions and Fertilizer Plant Greenhouse Gas", "abstract": "Agricultural activity is a significant source of greenhouse gas emissions. The fertilizer production process emits N2O, CO2, and CH4, and fertilized croplands emit N2O. We present continuous airborne observations of these trace gases in the Lower Mississippi River Basin to quantify emissions from both fertilizer plants and croplands during the early growing season. Observed hourly emission rates from two fertilizer plants are compared with reported inventory values, showing agreement for N2O and CO2 emissions but large underestimation in reported CH4 emissions by up to a factor of 100. These CH4 emissions are consistent with loss rates of 0.6-1.2%. We quantify regional emission fluxes (100 km) of N2O using the airborne mass balance technique, a first application for N2O, and explore linkages to controlling processes. Finally, we demonstrate the ability to use airborne measurements to distinguish N2O emission differences between neighboring fields, determining we can distinguish different emission behaviors of regions on the order of 2.5 km2 with emissions differences of approximately 0.026 \u03bcmol m-2 s-1. This suggests airborne approaches such as outlined here could be used to evaluate the impact of different agricultural practices at critical field-size spatial scales.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-20-5175-2020", "year": 2020, "title": "Design and evaluation of CO2 observation network to optimize surface CO2 fluxes in Asia using observation system simulation experiments", "abstract": "Abstract. Continuous efforts have been made to monitor atmospheric CO2 mole fractions as it is one of the most influential greenhouse gases in Earth's atmosphere. The atmospheric CO2 mole fractions are mostly determined by CO2 exchanges at the Earth's surface (i.e., surface CO2 flux). Inverse modeling, which is a method to estimate the CO2 exchanges at the Earth's surface, derives surface CO2 fluxes using modeled and observed atmospheric CO2 mole fraction data. Although observation data are crucial for successful modeling, comparatively fewer in situ observation sites are located in Asia compared to Europe or North America. Based on the importance of the terrestrial ecosystem of Asia for global carbon exchanges, more observation stations and an effective observation network design are required. In this paper, several observation network experiments were conducted to optimize the surface CO2 flux of Asia using CarbonTracker and observation system simulation experiments (OSSEs). The impacts of the redistribution of and additions to the existing observation network of Asia were evaluated using hypothetical in situ observation sites. In the case of the addition experiments, 10 observation stations, which is a practical number for real implementation, were added through three strategies: random addition, the influence matrix (i.e., self-sensitivity), and ecoregion information within the model. The simulated surface CO2 flux in Asia in summer can be improved by redistributing the existing observation network. The addition experiments revealed that considering both the distribution of normalized self-sensitivity and ecoregion information can yield better simulated surface CO2 fluxes compared to random addition, regardless of the season. This study provides a diagnosis of the existing observation network and useful information for future observation network design in Asia to estimate the surface CO2 flux and also suggests the use of an influence matrix for designing CO2 observation networks. Unlike other previous observation network studies with many numerical experiments for optimization, comparatively fewer experiments were required in this study. Thus, the methodology used in this study may be used for designing observation networks for monitoring greenhouse gases at both continental and global scales.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2019EF001421", "year": 2020, "title": "Doubling of U.S. Population Exposure to Climate Extremes by 2050", "abstract": "We quantify historical and projected trends in the population exposure to climate extremes as measured by the United States National Center for Environmental Information Climate Extremes Index (CEI). Based on the analyses of the historical observations, we find that the U.S. has already experienced a rise in the occurrence of aggregated extremes in recent decades, consistent with the climate response to historical increases in radiative forcing. Additionally, we find that exposure can be expected to intensify under the Representative Concentration Pathway 8.5, with all counties permanently exceeding the baseline variability in the occurrence of extreme hot days, warm nights, and drought conditions by 2050. As a result, every county in the U.S. is projected to permanently exceed the historical CEI variability (as measured by one standard deviation during the 1981-2005 period). Based on the current population distribution, this unprecedented change implies a yearly exposure to extreme conditions for one in every three people. We find that the increasing trend in exposure to the aggregated extremes is already detectable over much of the U.S., and particularly in the central and eastern U.S. The high correspondence between the pattern of trends in our simulations and observations increases confidence in the projected amplification of population exposure to unprecedented combinations of extreme climate conditions, should greenhouse gas concentrations continue to escalate along their current trajectory.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/ACP-19-14721-2019", "year": 2019, "title": "An increase in methane emissions from tropical Africa between 2010 and 2016 inferred from satellite data", "abstract": "Abstract. Emissions of methane (CH4) from tropical ecosystems, and how they respond to changes in climate, represent one of the biggest uncertainties associated with the global CH4 budget. Historically, this has been due to the dearth of pan-tropical in situ measurements, which is particularly acute in Africa. By virtue of their superior spatial coverage, satellite observations of atmospheric CH4 columns can help to narrow down some of the uncertainties in the tropical CH4 emission budget. We use proxy column retrievals of atmospheric CH4 (XCH4) from the Japanese Greenhouse gases Observing Satellite (GOSAT) and the nested version of the GEOS-Chem atmospheric chemistry and transport model (0.50.625) to infer emissions from tropical Africa between 2010 and 2016. Proxy retrievals of XCH4 are less sensitive to scattering due to clouds and aerosol than full physics retrievals, but the method assumes that the global distribution of carbon dioxide (CO2) is known. We explore the sensitivity of inferred a posteriori emissions to this source of systematic error by using two different XCH4 data products that are determined using different model CO2 fields. We infer monthly emissions from GOSAT XCH4 data using a hierarchical Bayesian framework, allowing us to report seasonal cycles and trends in annual mean values. We find mean tropical African emissions between 2010 and 2016 range from 76 (7478) to 80 (7882) Tg yr1, depending on the proxy XCH4 data used, with larger differences in Northern Hemisphere Africa than Southern Hemisphere Africa. We find a robust positive linear trend in tropical African CH4 emissions for our 7-year study period, with values of 1.5 (1.11.9) Tg yr1 or 2.1 (1.72.5) Tg yr1, depending on the CO2 data product used in the proxy retrieval. This linear emissions trend accounts for around a third of the global emissions growth rate during this period. A substantial portion of this increase is due to a short-term increase in emissions of 3 Tg yr1 between 2011 and 2015 from the Sudd in South Sudan. Using satellite land surface temperature anomalies and altimetry data, we find this increase in CH4 emissions is consistent with an increase in wetland extent due to increased inflow from the White Nile, although the data indicate that the Sudd was anomalously dry at the start of our inversion period. We find a strong seasonality in emissions across Northern Hemisphere Africa, with the timing of the seasonal emissions peak coincident with the seasonal peak in ground water storage. In contrast, we find that a posteriori CH4 emissions from the wetland area of the Congo Basin are approximately constant throughout the year, consistent with less temporal variability in wetland extent, and significantly smaller than a priori estimates.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.BUILDENV.2020.107243", "year": 2020, "title": "Modeling carbon dioxide exchange in a single-layer urban canopy model", "abstract": "Carbon dioxide (CO2) is the primary greenhouse gas that drives the global climate change in past centuries. Much effort of carbon mitigation as a countermeasure to global changes has focused on the urban areas the hotspots of fossil fuel and concentrated emission and pollutants. Despite their critical role in CO2 exchange in urban ecosystem, emission from vegetation and soils are largely overlooked in existing urban land surface models. In this study, we parameterized the biogenic CO2 exchange in cities using an advanced single-layer urban canopy model, by incorporating plant physiological functions in the built environment. In addition, the proposed model also includes the anthropogenic CO2 fluxes especially that from traffic emissions based on gridded dataset. We evaluate the proposed model using field measurements from an eddy covariance flux tower located at west Phoenix, Arizona, USA. The model results are in good agreement with the observed carbon flux over the built terrain, with a root mean squared error of 0.21 mg m2s1. Furthermore, our simulations show that the abiotic traffic-emitted CO2 amounts the largest source in cities, as expected. Nevertheless, the biogenic carbon exchange can be significantly enhanced in the built environment, making an equally important contributor to the total carbon emission especially in sub-urban areas.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-20-5249-2020", "year": 2020, "title": "Hadley cell expansion in CMIP6 models", "abstract": "Abstract. In response to increasing greenhouse gases, the subtropical edges of Earth's Hadley circulation shift poleward in global climate models. Recent studies have found that reanalysis trends in the Hadley cell edge over the past 3040 years are within the range of trends simulated by Coupled Model Intercomparison Project Phase 5 (CMIP5) models and have documented seasonal and hemispheric asymmetries in these trends. In this study, we evaluate whether these conclusions hold for the newest generation of models (CMIP6). Overall, we find similar characteristics of Hadley cell expansion in CMIP5 and CMIP6 models. In both CMIP5 and CMIP6 models, the poleward shift of the Hadley cell edge in response to increasing greenhouse gases is 23 times larger in the Southern Hemisphere (SH), except during SeptemberNovember. The trends from CMIP5 and CMIP6 models agree well with reanalyses, although prescribing observed coupled atmosphereocean variability allows the models to better capture reanalysis trends in the Northern Hemisphere (NH). We find two notable differences between CMIP5 and CMIP6 models. First, while both CMIP5 and CMIP6 models contract the NH summertime Hadley circulation equatorward (particularly over the Pacific sector), this contraction is larger in CMIP6 models due to their higher average climate sensitivity. Second, in recent decades, the poleward shift of the NH annual-mean Hadley cell edge is slightly larger in CMIP6 models. Increasing greenhouse gases drive similar trends in CMIP5 and CMIP6 models, so the larger recent NH trends in CMIP6 models point to the role of other forcings, such as aerosols.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.ATMOSENV.2021.118475", "year": 2021, "title": "Temporal evolution of mid-tropospheric CO2 over the Indian Ocean", "abstract": "The rapid increase in carbon dioxide (CO2) in the atmosphere due to anthropogenic activities aids global warming that demands immediate attention and policy actions. The changes in weather patterns, such as winds, temperature and precipitation, leading to floods and droughts are linked to the increasing greenhouse gases including CO2. This situation warrants close and continuous monitoring of atmospheric CO2. Here, the mid-tropospheric CO2 from Atmospheric Infrared Sounder (AIRS) is analysed for the past 14 years over Indian Ocean. The northern hemisphere has a higher CO2 concentration than the southern hemisphere, as most of the landmasses with significant CO2 sources are present in the former region. Seasonal variations show the highest CO2 concentration over the north Indian Ocean (NIO) during MAM (March, April and May), about 388.55 ppm, and lowest during ON (October and November), about 386.92 ppm. In contrast, the south Indian Ocean shows the highest, but the magnitude is smaller than that over NIO, during December, January and February. Arabian Sea (AS) exhibits smaller CO2 concentrations compared to that over Bay of Bengal (BoB). However, AS shows the highest trend of 2.13 ppm/year during the post-monsoon season (ON). The seasonal correlation analysis of the temperature at 10 m and sea surface temperature against mid-tropospheric CO2 shows a higher positive correlation for BoB. These analyses, therefore, provide a detailed understanding of the basin-wide seasonal and inter-annual trends of mid-tropospheric CO2 over Indian Ocean.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1109/IGARSS.2019.8897802", "year": 2019, "title": "Introducing Satellite Data Based Biosphere Model Beams to Improve Regional Transport Model Aist-Mm for Estimating Carbon Dioxide Emission from Mega-City \u2026", "abstract": "Remote sensing data from GOSAT (Greenhouse gases Observing SATellite) and GOSAT-2 in the future ameliorate inversion analysis of greenhouse gas (GHG) emissions[1],[2]. Meso-scale atmospheric transport model AIST-MM (National Institute of Advanced Industrial Science and Technology-Mesoscale Model)[3],[4] and global-scale transport model NICAM-TM (Nonhydrostatic ICosahedral Atmospheric Model-Transport Model)[5] have been coupled for data assimilation in order to estimate CO2 emission from mega-city Tokyo. However, forests west and north of Tokyo Metropolis in the Kanto plain generate significant biogenic CO2 fluxes and such atmosphere-biosphere gas exchange remains to be properly calculated during the modeling processes. In this study, we use MODIS products[6],[7] to simulate regional gross primary production (GPP), vegetational and soil respirations based on Biosphere model integrating Eco-physiological And Mechanistic approaches using Satellite data (BEAMS) algorithms[8],[9]. By integrating this atmosphere-terrestrial ecosystem carbon balance module to our regional inversion analysis, we aim at more precise estimation of CO2 emission from Tokyo.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.MARCHEM.2020.103867", "year": 2020, "title": "Factors controlling the variability and emissions of greenhouse gases (CO2, CH4 and N2O) in three estuaries of the Southern Iberian Atlantic Basin during July 2017", "abstract": "The partial pressure of CO2 (pCO2) and concentration of dissolved CH4 and N2O were studied during July 2017 in three estuaries of the southern Iberian Atlantic basin: the Guadalquivir, Tinto - Odiel and Guadiana. Two different sampling methods were adopted for each estuary: a longitudinal sampling along the course of the river, and a tidal cycle sampling of 24 h in the mouth of the estuary. In general, there is an increase in the concentration of gases towards the inner part of the river, in all three systems. Daily variations coupled to the tidal cycles were also observed in the three estuaries. The highest concentrations were measured during ebb, which suggests that the estuaries export CO2, CH4 and N2O to the Gulf of Cadiz. These three gases showed the highest value and range of variation in the Guadalquivir (pCO2: 959 1009 atm, CH4: 54.1 74.5 nM, N2O: 14.1 16.1 nM), followed by the Guadiana (pCO2: 595 155 atm, CH4: 53.5 62.9 nM, N2O: 7.1 0.5 nM), and the Tinto - Odiel (pCO2: 581 204 atm, CH4: 39.6 43.5 nM, N2O: 6.8 0.3 nM). Changes in pCO2 values and CH4 and N2O concentrations were affected by several factors: temperature, salinity, exchange with the atmosphere, reactivity of the gases and various physical and biological processes taking place in the estuaries object of study. The water - atmosphere fluxes of pCO2, CH4 and N2O resulted positive, revealing that the study area acts as a source of these gases to the atmosphere.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2022JD037328", "year": 2022, "title": "Characteristics of deep convective clouds, precipitation, and cloud properties of rapidly intensifying tropical cyclones in the western North Pacific", "abstract": "Toward the understanding of rapid intensification (RI) of tropical cyclones (TCs) in the western North Pacific, the TC's deep convective cloud (DCC), precipitation, and cloud properties in terms of cloud effective radius, optical thickness, and top height from satellite observations are investigated. Mean and radial distributions of the variables at different intensity stages and intensification categories are examined. The relationship indicates that the DCC percentage and temperature, especially their radial distributions, could be used to identify an impending RI regardless of TC intensity. Meanwhile, the mean and radial distribution of precipitation may discriminate RI from non-RI in tropical depression (TD) and tropical storm (TS). The radial distribution of the cloud properties in rapidly intensifying TD and TS also suggest that most of the clouds near the center of the storm has deepened already while those that are far from the center are generally in developing or dissipating stage. Moreover, rapidly intensifying TCs, regardless of their intensities, manifest common DCC, precipitation, and cloud properties characteristics near the TC center. It is to be noted that the different mean and radial distribution characteristics of the variables between initial and continuing stages of RI are inferred to be artifacts of their intensities and RI rates (or radius of maximum wind sizes) rather than whether the TCs are at the onset or 24 hr of RI.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2019GL086620", "year": 2020, "title": "Upright Convection in Extratropical Cyclones: A Survey Using", "abstract": "Upright convection can impact extratropical cyclone (ETC) precipitation and dynamics differently than isentropic ascent, but how often it occurs and how much it contributes to total precipitation within an ETC have not been systematically documented in previous literature. Herein, convection in ETCs is analyzed using ground-based radar observations over the Eastern United States. Convection occupies 1%-5% of the precipitating region and constitutes 1%-15% of total cyclone precipitation. Furthermore, the location of convective activity occurs preferentially in the warm sector early in a cyclone's life cycle, and then as the storm evolves, more convection occurs along and behind the cold front. The precipitation rates in regions with convection are more likely to be stronger than those in other precipitating regions of the cyclone. However, the cyclones with the largest area-average precipitation rates include only a small contribution from convection.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1038/S43247-021-00204-9", "year": 2021, "title": "Accounting for tropical cyclones more than doubles the global population exposed to low-probability coastal flooding", "abstract": "Storm surges that occur along low-lying, densely populated coastlines can leave devastating societal, economical, and ecological impacts. To protect coastal communities from flooding, return periods of storm tides, defined as the combination of the surge and tide, must be accurately evaluated. Here we present storm tide return periods using a novel integration of two modelling techniques. For surges induced by extratropical cyclones, we use a 38-year time series based on the ERA5 climate reanalysis. For surges induced by tropical cyclones, we use synthetic tropical cyclones from the STORM dataset representing 10,000 years under current climate conditions. Tropical and extratropical cyclone surge levels are probabilistically combined with tidal levels, and return periods are computed empirically. We estimate that 78 million people are exposed to a 1 in 1000-year flood caused by extratropical cyclones, which more than doubles to 192 M people when taking tropical cyclones into account. Our results show that previous studies have underestimated the global exposure to low-probability coastal flooding by 31%.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.RSE.2022.113256", "year": 2022, "title": "The potential of spaceborne GNSS reflectometry for detecting ocean surface currents", "abstract": "The detectability of ocean surface currents in global navigation satellite system reflectometry (GNSS-R) observations is analyzed. We use a large dataset of spaceborne GNSS-R measurements from NASA cyclone GNSS (CYGNSS) mission. The data is collocated with ocean wind and near-surface current measurements. Our analysis reveals clear responses of the GNSS-R 0 to the presence of currents. The response depends on the wind conditions and is more prominent for wind speeds below 6 m/s. A current velocity of 0.5 m/s under an opposing wind can, on average, suppress the GNSS-R 0 by 0.8 decibels for low incidence angles. The interaction of the same current with a codirectional wind can enhance 0 by almost the same amount. This enhancement is most visible at high incidence angles. We develop a model that improves the prediction of the GNSS-R 0 in the presence of surface currents. The detected signatures of windcurrent interactions highlight the potential of GNSS-R sensors onboard small satellites for observing ocean surface currents.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1109/TGRS.2018.2883358", "year": 2019, "title": "A simple approximation for the reflectance of a thick cloud in gaseous absorption band and its application for the cloud-top height determination", "abstract": "This paper presents a new, simple, fast method to retrieve cloud altitude from measurements of light absorption in the strongest molecular band of oxygen (the A-band), centered at 761 nm, by the polarization and directionality of the earth's reflectance sensor. First, we assess the validity of the method against synthetic spectra as a function of realistic cloud scenarios and satellite observation geometries. The retrieval error estimate amounts, on average, to less than 500 m. Second, the hurricane Ileana, overpassed the August 30, 2012, off the coasts west of Mexico and Southern California, is selected as test bed for the comparison of our retrievals against independent and nearly coincident cloud data inferred with the Moderate Resolution Imaging Spectroradiometer onboard Aqua and the Global Ozone Monitoring Experiment 2 onboard MetOp-A. We find that our approach can accurately reproduce the cloud height patterns, as long as the clouds are not thin cirrus.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/NHESS-20-1463-2020", "year": 2020, "title": "Brief communication: Hurricane Dorian: Automated near-real-time mapping of the \u201cunprecedented\u201d flooding in the Bahamas using synthetic aperture radar", "abstract": "Abstract. In this communication, we present application of the automated near-real-time (NRT) system called RAdar-Produced Inundation Diary (RAPID) to European Space Agency Sentinel-1 synthetic aperture radar (SAR) images to produce flooding maps for Hurricane Dorian in the northern Bahamas. RAPID maps, released 2 d after the event, show that coastal flooding in the Bahamas reached areas located more than 10 km inland, covering more than 3000 km2 of continental area. RAPID flood estimates from subsequent SAR images show the recession of the flood across the islands and present high agreement scores when compared to Copernicus Emergency Management Service (Copernicus EMS) estimates.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/JOC.7477", "year": 2021, "title": "Vertical variation of tropical cyclone size in the western North Pacific", "abstract": "Based on the ERA5 reanalysis dataset, this paper examines the vertical variation of tropical cyclone (TC) size in the western North Pacific during 1998-2018. The TC size is defined as the distance from the TC centre to the radius at which the azimuthally averaged relative vorticity decreases to 1 \u00d7 10\u22125 s\u22121 (Rvor). It is found that TCs with similar sizes at the surface can be significantly different in size at higher levels. The Rvor at 10 m height (Rvor10) and that at 200 hPa (Rvor200) are related to TC intensity categories, and Rvor10 and that at 700 hPa (Rvor700) correlate linearly with the relative sea surface temperature (RSST) averaged within a 500-km radius. Further, a positive correlation is found between the 500-km radius averaged rain rate and Rvor200, while Rvor10, Rvor700 and Rvor200 all decrease with an increasing vertical wind shear (VWS). The spatial distributions of Rvor10, Rvor700, Rvor200 and Vmax, RSST, and rain rate are all similar to one another, and the spatial correlation coefficient between any pair of variations is larger than 0.91, which is statistically significant at the 0.01 level. The monthly variations of Rvor10, Rvor700 and Rvor200 are generally larger in the months with strong TC activity (May-October) than in the other months, although a peak of Rvor10 during March has been identified for the more recent few TCs. No significant interannual trend is found during 1998-2018 for any of the three variables (Rvor10, Rvor700 and Rvor200). Statistically significant correlations between the ENSO (El Ni\u00f1o-Southern Oscillation) index and Rvor10 and Rvor200 are 0.54 and 0.47, respectively, while no statistically significant correlation is found between the ENSO index and Rvor700. The mechanisms that affect the TC size at different heights are complicated and will be explored in later studies.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/ACP-17-12421-2017", "year": 2017, "title": "The influence of mid-latitude cyclones on European background surface ozone", "abstract": "Abstract. The relationship between springtime mid-latitude cyclones and background ozone (O3) is explored using a combination of observational and reanalysis data sets. First, the relationship between surface O3 observations at two rural monitoring sites on the west coast of Europe Mace Head, Ireland, and Monte Velho, Portugal and cyclone track frequency in the surrounding regions is examined. Second, detailed case study examination of four individual mid-latitude cyclones and the influence of the associated frontal passage on surface O3 is performed. Cyclone tracks have a greater influence on the O3 measurements at the more northern coastal European station, Mace Head, located within the main North Atlantic (NA) storm track. In particular, when cyclones track north of 53 N, there is a significant relationship with high levels of surface O3 (> 75th percentile). The further away a cyclone is from the NA storm track, the more likely it will be associated with both high and low (< 25th percentile) levels of O3 at the observation site during the cyclone's life cycle. The results of the four case studies demonstrate (a) the importance of the passage of a cyclone's cold front in relation to surface O3 measurements, (b) the ability of mid-latitude cyclones to bring down high levels of O3 from the stratosphere, and (c) that accompanying surface high-pressure systems and their associated transport pathways play an important role in the temporal variability of surface O3. The main source of high O3 to these two sites in springtime is from the stratosphere, either from direct injection into the cyclone or associated with aged airstreams from decaying downstream cyclones that can become entrained and descend toward the surface within new cyclones over the NA region.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.DYNATMOCE.2022.101334", "year": 2022, "title": "On the dynamics of the eradication of a warm core mesoscale eddy after the passage of Hurricane Irma (2017)", "abstract": "Mesoscale oceanic eddies are known to influence air-sea interactions during tropical cyclone (TC) passage by either hindering or sustaining air-sea fluxes into the TC core. However, little is known as to how TCs alter the dynamical structure of such eddies during and after TC passage. Through simulations of Hurricane Irma (2017) using the Navys Coupled Ocean Atmospheric Mesoscale Prediction Scheme for Tropical Cyclones, it is found that a simulated mesoscale warm core eddy (WCE) located to the right of the model track disappeared shortly after the TC had passed over it. To further explore this phenomena, time series of ocean kinetic energy, available potential energy (APE), a vorticity budget, and a potential vorticity (PV) budget are examined to understand how TC-induced upper ocean currents influenced the eddy disappearance. Time series of APE within the model-simulated eddy show APE reaching a minimum as the circulation of the eddy disappeared in the model field and positive vorticity, dominated by vertical vorticity advection, became a maximum approximately 6 h after TC passage. These results were confirmed by the PV budget. The succession of subsurface vorticity changes suggest that the WCE was eradicated by a near-inertial wave wake that occurred earlier than expected. As found in a prior study, the early-onset of a near-inertial wake occurs when the model simulated TC with a small radius of maximum winds interacts with the subsurface ocean current field. The findings are important with regards to TC forecasting because the accurate representation and placement of eddies in the model field is necessary to correctly predict the coupled air-sea response during TC passage and for subsequent TCs with similar tracks. Such feedbacks from TCs can also have near-term and long-term influence on the prediction of air-sea interaction in the local and regional marine environment.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2021JD035097", "year": 2021, "title": "Examining the Capacity of Hurricane Matthew (2016) in Spawning Halo/Sprite\u2010Producible Lightning Strokes During Its Lifetime", "abstract": "This paper evaluated the overall capability of a hurricane in posing the electromagnetic impact on the high-altitude atmosphere. Oceanic thunderstorms are more efficient in producing negative polarity cloud-to-ground (CG) strokes with large impulse charge moment changes (iCMCs) than continental thunderstorms. As the strongest oceanic thunderstorms, hurricanes' capability to produce transient luminous events is desired to be examined. Here, we investigated the halo/sprite production of hurricane Matthew (2016) by examining the iCMCs of lightning detected by the World-Wide Lightning Location Network hour by hour at nighttime, based on the ultra-low frequency (ULF) magnetic field of the lightning strokes. Matthew was likely an active halo/sprite producer and produced more than 1,000 halo/sprite producible strokes (H/S strokes) with iCMCs exceeding the threshold (200 C km) for producing halo/sprite. The peak of H/S strokes in the outer rainband lags about one day behind the maximum hurricane strength. Additionally, the absence of positive sprite-producible strokes in the inner core (0-100 km) of Matthew may be attributed to the spiral warm cloud feature, although many negative halos could be produced instead because 112 halo/sprite producible strokes were identified here with 89% being negative. In contrast, the outer rainband exhibits some features of the trailing stratiform region of continental mesoscale convective systems (MCSs) and has been a favorable region of halo/sprite production. Overall, the inner core of Matthew and probably also that of other hurricanes bear the features that make the oceanic thunderstorms a proficient producer of negative halos but not sprites.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/ASL.1028", "year": 2021, "title": "On the vertical extending of the explosive extratropical cyclone: A case", "abstract": "Explosive extratropical cyclone (EEC) is the main disastrous weather system over the ocean and offshore areas in the cold season. As a type of vertically deep system, after decades of studies, key features of EECs' vertical extents still remain vague. Based on a reasonably simulated entire-troposphere-thick EEC, this study analyzes variation of the EEC's vertical extent and investigates governing mechanisms for its vertical extending. Main findings are as follows: (a) the EEC's vertical extent showed consistent variation features with its central sea level pressure and lower-level vorticity (correlation coefficients were ~0.9), whereas its relationship with EEC's maximum surface wind was not significant; (b) EEC's upward extending featured strong ascending motion and rapid cyclonic-vorticity enhancement at the top level of the cyclone and obvious inflow (convergence) in the lower troposphere. (c) vorticity budget at the EEC's top level shows that net import transport of cyclonic vorticity (by westerly and northwesterly winds) from the trough west of the cyclone dominated its upward extending, and upward transport of cyclonic vorticity from levels below the cyclone's top level acted as the second dominant factor. In contrast, divergence-related vertical shrinking around the EEC's top level was the most detrimental factor for the cyclone's upward extending.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/BAMS-D-15-00186.1", "year": 2016, "title": "NASA's hurricane and severe storm sentinel (HS3) investigation", "abstract": "Abstract The National Aeronautics and Space Administrations (NASA) Hurricane and Severe Storm Sentinel (HS3) investigation was a multiyear field campaign designed to improve understanding of the physical processes that control hurricane formation and intensity change, specifically the relative roles of environmental and inner-core processes. Funded as part of NASAs Earth Venture program, HS3 conducted 5-week campaigns during the hurricane seasons of 201214 using the NASA Global Hawk aircraft, along with a second Global Hawk in 2013 and a WB-57f aircraft in 2014. Flying from a base at Wallops Island, Virginia, the Global Hawk could be on station over storms for up to 18 h off the East Coast of the United States and up to about 6 h off the western coast of Africa. Over the 3 years, HS3 flew 21 missions over nine named storms, along with flights over two nondeveloping systems and several Saharan air layer (SAL) outbreaks. This article summarizes the HS3 experiment, the missions flown, and some preliminary findings related to the rapid intensification and outflow structure of Hurricane Edouard (2014) and the interaction of Hurricane Nadine (2012) with the SAL.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.FORECO.2017.10.015", "year": 2017, "title": "Abiotic and biotic changes at the basin scale in a tropical dry forest landscape after Hurricanes Jova and Patricia in Jalisco, Mexico", "abstract": "Given the current evidence of global change, extreme events are projected to be more frequent and intense. At a river basin scale, the immediate effects of hurricanes include changes in soil properties, vegetation structure and composition, and water volume and quality, which lead to changes in species distribution and community structure. The goal of this study was to identify key abiotic and biotic elements for monitoring hurricane events at the river basin scale by linking databases of vegetation cover, small mammal diversity and water quality between 2010 and 2016. Abiotic parameters and biotic communities were monitored in a tropical dry forest (TDF) landscape on the coast of Jalisco, Mexico after two major events: Hurricanes Jova (2011) and Patricia (2015). Three zones (1-upper, 2-middle and 3-lower basin) adjacent to the TDF were analyzed along the Cuitzmala River catchment areas before and after the events. We used the Enhanced Vegetation Index (EVI) as a proxy for vegetation greenness and the diversity index of a small mammal community of rodents and bats as indicators of terrestrial habitat quality, and Fecal Coliform (FC), Fecal Enterococci (FE), and Electrical Conductivity (EC) as indicators of the river-water condition. During the years of hurricanes (2011 and 2015) there was a decrease in the EVI and small mammal diversity, as well as changes in the concentration of FC, FE and EC. The main effects associated with the two hurricanes were observed in the lower basin where hurricanes made landfall and the forest had been converted to other land uses. The EVI, communities of small mammals, and abiotic and biotic water conditions were responsive to the effects of hurricanes and can thus be useful for a long-term ecological monitoring program at the basin scale. This program would allow a faster evaluation and response to future extreme meteorological events. Our results could be implemented through the Urban and Environmental Plans at the state level (Ordenamiento Territorial del Estado de Jalisco), through the regulation of sustainable agricultural and livestock techniques, and by educating local populations of the effects of extreme meteorological events.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.6057/2015TCRRH3.03", "year": 2015, "title": "An introduction to the NASA East Pacific Origins and Characteristics of Hurricanes (EPOCH) field campaign", "abstract": "Over the past five years, tropical activity in the East Pacific has increased, while declining in the Atlantic Basin. In addition, during El Nino years, warmer than average sea surface temperatures further increase the likelihood of tropical cyclone formation in the East Pacific. Hurricane field campaigns used the Ku-/Ka-band High-Altitude Wind and Rain Airborne Profiler (HIWRAP) radar on the Global Hawk (GH) unmanned aircraft, in GRIP (Genesis and Rapid Intensification Processes 2010), HS3 (Hurricane and Severe Storm Sentinel 2012-14), and the NOAA Sensing Hazards with Operational Unmanned Technology (SHOUT 2015-16) field campaigns. Although originally designed for the GH, the X-band high-altitude RADar (EXRAD) has yet to be integrated and flown on an unmanned aerial vehicle. EXRAD will provide data with less attenuation of signal over deep convection as well as better estimates of three-dimensional winds with its nadir-pointing beam. As part of the NASA Hand On Project Experience (HOPE) Training Opportunity, our team proposed to fly the AV-6 GH aircraft with the EXRAD radar, the High Altitude MMIC Sounding Radiometer (HAMSR), and NOAA Advanced Vertical Atmospheric Profiling System (AVAPS) dropsondes to investigate genesis and/or rapid intensification (RI) of an East Pacific hurricane by measuring both the environment and interior structures. Information on planned activities primarily focused on the EXRAD high-altitude radar integration for the July-August 2017 science flight will be presented.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1073/PNAS.2006213117", "year": 2020, "title": "Government effectiveness and institutions as determinants of tropical cyclone mortality", "abstract": "Significance\r\n Tropical cyclone disasters frequently result in substantial loss of life. Institutional capacity and economic development are believed to play protective roles, but previous efforts have been unable to disentangle their relative effects. We establish empirically that stronger national and subnational institutions, independent of income, are associated with lower tropical cyclone mortality. This suggests that effective institutions play an important role in the success of disaster risk reduction strategies. Our approach of accounting for hazard intensity, population exposure, and socioeconomic conditions at high resolutions can be extended to other hazards and scales to further examine how institutions moderate risk.\r\n , \r\n Strong institutions as well as economic development are generally understood to play critical roles in protecting societies from the adverse impacts of natural hazards, such as tropical cyclones. The independent effect of institutions on reducing these risks, however, has not been confirmed empirically in previous global studies. As a storms path and intensity influence the severity of the damages and may be spatially correlated with human vulnerabilities, failing to accurately capture physical exposure in an econometric analysis may result in imprecise and biased estimates of the influence of the independent variables. Here, we develop an approach to control for physical exposure by spatially interacting meteorological and socioeconomic data for over 1,000 tropical cyclone disasters from 1979 to 2016. We find evidence that higher levels of national government effectiveness are associated with lower tropical cyclone mortality, even when controlling for average income and other socioeconomic conditions. Within countries, deaths are higher when strong winds are concentrated over areas of the country with elevated infant mortality rates, an indicator of institutional effectiveness through public service delivery. These results suggest that policies and programs to enhance institutional capacity and governance can support risk reduction from extreme weather events.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.UCLIM.2019.100506", "year": 2019, "title": "Statistics on typhoon landfalls in Vietnam: can recent increases in economic damage be attributed to storm trends?", "abstract": "The Emergency Events Database (EM-DAT) indicates that the economic damage associated with storms has been rapidly growing in Vietnam. By contrast, the fatality rate due to storm-relevant disasters has been declining in recent decades. This study investigates whether typhoon trends have affected these outcomes. Best track data from the Japan Meteorological Agency (JMA) were examined to estimate central pressure and wind speed when typhoons made landfall. From 1977 to 2017, typhoons with wind speeds above 20 knots struck the country 105 times. A statistical analysis, which defined a storm's intensity using principal component analysis (PCA), revealed that Typhoon Doksuri in 2017 was the strongest among the collection, followed by Cecil in 1985, Xangsane in 2006, and Damrey in 2017. The worst storm in history, Typhoon Linda in 1997, claimed over 3500 lives in southern Vietnam, but was only ranked 37th, demonstrating that typhoon intensity is not always the determining factor of fatalities. Moreover, the analysis of variance (ANOVA) illustrates that none of the meteorological trends such as frequency, central pressure, wind speed, or storm intensity show any significant increase or decrease over the last four decades. However, landfall frequency has risen significantly, particularly in the northernmost part of the country where two large cities, Hanoi and Hai Phong, are located. A strong correlation was found between intensity and recent economic damage (r = 0.80) based on the proposed index of positive annual landfall storm intensity (PALSI). Given all of these factors, it is reasonable to attribute the expansion of disaster-related economic damage to economic development and the fundamental volatility of typhoons.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/NHESS-22-2359-2022", "year": 2022, "title": "Storm surge hazard over Bengal delta: a probabilistic-deterministic", "abstract": "Abstract. Storm-surge-induced coastal inundation constitutes a substantial threat to lives and properties along the vast coastline of the Bengal delta. Some of the deadliest cyclones in history made landfall in the Bengal delta region claiming more than half a million lives over the last five decades. Complex hydrodynamics and observational constraints have hindered the understanding of the risk of storm surge flooding of this low-lying (less than 5 m above mean sea level), densely populated (> 150 million) mega-delta. Here, we generated and analysed a storm surge database derived from a large ensemble of 3600 statistically and physically consistent synthetic storm events and a high-resolution storm surge modelling system. The storm surge modelling system is developed based on a custom high-accuracy regional bathymetry enabling us to estimate the surges with high confidence. From the storm surge dataset, we performed a robust probabilistic estimate of the storm surge extremes. Our ensemble estimate shows that there is a diverse range of water level extremes along the coast and the estuaries of the Bengal delta, with well-defined regional patterns. We confirm that the risk of inland storm surge flooding at a given return period is firmly controlled by the presence of coastal embankments and their height. We also conclude that about 10 % of the coastal population is living under the exposure of a 50-year return period inundation under current climate scenarios. In the face of ongoing climate change, which is likely to worsen the future storm surge hazard, we expect our flood maps to provide relevant information for coastal infrastructure engineering, risk zoning, resource allocation, and future research planning.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3389/FEART.2022.839733", "year": 2022, "title": "Risk Assessment of Typhoon Disaster Chains in the GuangdongHong KongMacau Greater Bay Area, China", "abstract": "The typhoon disaster chain is one of the leading climate risks in constructing the GuangdongHong KongMacau Greater Bay Area (GBA). In this study, the risks of the typhoon disaster chains including typhoon-induced gales, rainstorms, and storm surges in the GBA, as well as the comprehensive risk of typhoon disaster, are investigated at county level by comprehensively analyzing the hazard, exposure, and vulnerability. The results show that the high- and very-high-risk areas of typhoongale disaster chain are located in Zhuhai, Zhongshan, Foshan, Dongguan, central-southern Jiangmen, southern Shenzhen, and parts of Huizhou. The high- and very high-risk areas of typhoonrainstorm disaster chain include Zhuhai, Zhongshan, Shenzhen, central-southern Foshan, northern Dongguan, central Jiangmen, and central Huizhou. Regarding the typhoonstorm surge disaster chain, the areas at high and very high risk are located in Zhuhai, eastern Zhongshan, and the coastal areas of the Pearl River Estuary. In addition, the comprehensive risk of typhoon disaster is very high in Zhuhai and high in Zhongshan, Jiangmen, Dongguan, and Shenzhen. By verifying the spatial correlation between typhoon disaster risk indexes and actual losses, it is found that the comprehensive risk index of typhoon disaster constructed in this study can better reflect the actual losses. Overall, the findings of this study can provide a scientific basis for typhoon disaster prevention and mitigation in the GBA, and it can also serve as a reference for typhoon disaster risk research in other areas.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1109/IGARSS46834.2022.9883409", "year": 2022, "title": "CYGNSS GNSS-R Data for Inundation Monitoring in the Brazilian Pantanal Wetland", "abstract": "Global Navigation Satellite System Reflectometry (GNSS-R) that uses signals of opportunity in L-band microwave frequency is an optimal system for Earth surface remote sensing. Spaceborne GNSS-R is a very promising bistatic radar system to detect, estimate and monitor inundation extents as it collects GNSS reflections in a good spatiotemporal resolution and is not affected by clouds and, to some extent, aboveground vegetation. In this contribution, we propose a new method to estimate the inundation extent of the Brazilian Pantanal wetland using three years (Aug. 2018 - Jul. 2021) of data from NASA Cyclone GNSS (CYGNSS) mission. The proposed method is independent in variations of the transmitted signal power and angle of incidence as the inundation extent is estimated track by track. We find very good agreement between the GNSS-R inundation extent retrievals and those derived from different remote sensing techniques with a correlation of 0.92.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1175/MWR-D-17-0095.1", "year": 2018, "title": "The inner-core temperature structure of Hurricane Edouard (2014): Observations and ensemble variability", "abstract": "Abstract The inner-core thermodynamic structure of Hurricane Edouard (2014) is explored, primarily through an examination of both high-altitude dropsondes deployed during NASAs Hurricane and Severe Storm Sentinel (HS3) and a 60-member convection-permitting ensemble initialized with an ensemble Kalman filter. The 7-day forecasts are initialized coincident with Edouards tropical depression designation and include Edouards significant intensification to a major hurricane. Ten-member ensemble groups are created based on timing of nearrapid intensification (RI) onset, and the associated composite inner-core temperature structures are analyzed. It is found that at Edouards peak intensity, in both the observations and the simulations, the maximum inner-core perturbation temperature (~1012 K) occurs in the midlevels (~48 km). In addition, in all composite groups that significantly intensify, the evolution of the area-averaged inner-core perturbation temperatures indicate that weak to moderate warming (at most 4 K) begins to occur in the low to midlevels (~26 km) ~2448 h prior to RI, and this warming significantly strengthens and deepens (up to ~8 km) ~24 h after RI has begun. Despite broad similarities in the evolution of Edouards warm core in these composites, variability in the height and strength of the maximum perturbation temperature and in the overall development of the inner-core temperature structure are present among the members of the composite groups (despite similar intensity time series). This result and concomitant correlation analyses suggest that the strength and height of the maximum perturbation temperature is not a significant causal factor for RI onset in this ensemble. Fluctuations in inner-core temperature structure occur either in tandem with or after significant intensity changes.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2018JD029446", "year": 2019, "title": "The Tropical Transition in the Western North Pacific: The Case of Tropical Cyclone Peipah (2007)", "abstract": "This study examines the transition of an extratropical disturbance to a tropical cyclone (TC), Peipah (2007), in the western North Pacific (WNP), using reanalysis and geostationary satellite data. Instead of regular diurnal fluctuations of deep convection, the pre-TC disturbance accompanies deep convection only for short durations every other day. When the pre-TC vorticity is traced back to 7 days prior to its formation, the traced-back vorticity indicates a strong potential vorticity (PV) trough in the subtropical upper troposphere that originated from the midlatitude lower stratosphere. The quasi-geostrophic forcing and reduced static stability at the leading edge of the PV trough result in the formation of an extratropical disturbance. The vertical structure of the extratropical disturbance shows maximum vorticity in the upper troposphere and cold temperature anomaly within it throughout the entire troposphere. As the extratropical disturbance moved into the tropical WNP, deep convection associated with quasi-geostrophic dynamics over the warm ocean initiated tropical transition of the extratropical disturbance to a TC through diabatic redistribution of PV in the tropospheric column as well as transition of the cold anomaly into a warm anomaly within the vortex. With additional contribution of barotropic energy conversion in the lower troposphere, the warm-core low system finally developed into a TC-strength vortex. These results indicate that PV troughs of the stratospheric origin over the subtropical Pacific Ocean can contribute to TC formations in the WNP.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2020JD033616", "year": 2021, "title": "Role of Extratropical Wintertime Cyclones in Regulating the Variations", "abstract": "A cyclone is an intensive synoptic activity that occurs frequently over Baffin Bay. By modifying the large scale distribution pattern of sea level pressure, a passing cyclone can serve as an important regulator of sea ice outflow via the Davis Strait. We obtain a nearly 40 year long record (1979/1980-2017/2018) of the sea ice area flux (SIAF) through the Davis Strait and Arctic cyclone activities in winter. A case study and statistical results indicate that the sea ice concentration and motion fields can be greatly altered by the occurrence of cyclones, thereby contributing to changes in sea ice export. Moreover, the effects of cyclones on sea ice export in Baffin Bay are dependent on the spatial distribution pattern of the storms. In terms of the cyclone center count and intensity, the key regions with significant impacts on sea ice export out of Baffin Bay are identified, one around Baffin Island (80\u00b0W-60\u00b0W, 60\u00b0N-70\u00b0N) and the other over the southern Labrador Peninsula (70\u00b0W-50\u00b0W, 40\u00b0N-60\u00b0N). A robust correlation exists between the winter accumulated SIAF via the Davis Strait and the average winter cyclone intensity (center count) in the critical regions with R = \u22120.57 (+0.49), affirming the vital role of cyclone activity in modulating the interannual variability of sea ice export in Baffin Bay.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1111/GEB.13407", "year": 2022, "title": "Disturbance frequency, intensity and forest structure modulate cyclone\u2010induced changes in mangrove forest canopy cover", "abstract": "AimTropical cyclones are large\u2011scale disturbances that can shape the structure and dynamics of mangrove forests. Although tropical cyclone activity overlaps extensively with the latitudinal distribution of mangrove forests, the relationships between cyclone intensity and frequency and mangrove forest canopy damage and recovery are not understood at the global scale. Using remote sensing data, we examined how mangrove forest structure, climate and cyclone characteristics influence canopy cover loss and recovery dynamics.LocationGlobal tropics.Time period2000\u20132020.Major taxa studiedMangrove trees.MethodsUsing two satellite\u2011derived vegetation indices (the enhanced vegetation index and the normalized difference infrared index) from 86 cyclones affecting 56 mangrove sites across the globe, we quantified mangrove canopy loss in relationship to cyclones. Using linear regression and variance decomposition, we identified and ranked significant predictors of cyclone\u2011induced canopy loss and recovery.ResultsThree\u2011quarters of the studied cyclone disturbances resulted in canopy damage. Stands exposed to high wind speeds and those close to the cyclone paths were more severely damaged, whereas lower damage magnitudes were found in sites with greater past cyclone frequency. Canopy damage was greater in tall mangrove stands but decreased with higher aboveground biomass. The distance from the cyclone path and maximum wind speed were the most important factors, representing > 50% of the explained variation in cyclone damage. There was considerable variation in canopy damage among cyclones, but rates of recovery were similar across all mangrove sites, with the main predictor of recovery time being the degree of canopy loss.Main conclusionsOur results suggest that the resistance of mangrove canopy cover to cyclone disturbance is variably tuned to the cyclone regime and vegetation characteristics, but resilience is inherent to the magnitude of canopy damage because the rate of forest canopy recovery appears to be consistent globally.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1117/1.JRS.11.032410", "year": 2017, "title": "Inflow of shelf waters into the Mississippi Sound and Mobile Bay estuaries in October 2015", "abstract": "The exchange of coastal waters between the Mississippi Sound (MSS), Mobile Bay, and Mississippi Bight is an important pathway for oil and pollutants into coastal ecosystems. This study investigated an event of strong and persistent inflow of shelf waters into MSS and Mobile Bay during October 2015 by combining in situ measurements, satellite ocean color data, and ocean model predictions. Navy Coastal Ocean Model predicted high-salinity shelf waters continuously flowing into the estuarine system and forecasted low-salinity waters trapped inside the estuaries which did not flush out until the passage of tropical cyclone Patricias remnants in late October. The October 2015 chlorophyll-a anomaly was significantly low inside and outside the MSS for the 2003 to 2015 time series. Similar low-chlorophyll-a anomalies were only seen in 2003. The October 2015 mean in situ salinities were up to 8 psu higher than mean from 2007 to 2015, and some estuarine stations showed persistent salinities above 30 psu for almost a month in agreement with model predictions. October 2015 was associated with low fall seasonal discharge, typical of fall season, and wind which was persistently out of the east to southeast [45180]. These persistent wind conditions were linked to the observed anomalous conditions.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JPO-D-19-0277.1", "year": 2020, "title": "Upper-Ocean Response to Precipitation Forcing in an Ocean Model Hindcast of Hurricane Gonzalo", "abstract": "Abstract Preexisting, oceanic barrier layers have been shown to limit turbulent mixing and suppress mixed layer cooling during the forced stage of a tropical cyclone (TC). Furthermore, an understanding of barrier layer evolution during TC passage is mostly unexplored. High precipitation rates within TCs provide a large freshwater flux to the surface that alters upper-ocean stratification and can act as a potential mechanism to strengthen the barrier layer. Ocean glider observations from the Bermuda Institute of Ocean Sciences (BIOS) indicate that a strong barrier layer developed during the approach and passage of Hurricane Gonzalo (2014), primarily as a result of freshening within the upper 30 m of the ocean. Therefore, an ocean model case study of Hurricane Gonzalo has been designed to investigate how precipitation affects upper-ocean stratification and sea surface temperature (SST) cooling during TC passage. Ocean model hindcasts of Hurricane Gonzalo characterize the upper-ocean response to TC precipitation forcing. Three different vertical mixing parameterizations are tested to determine their sensitivity to precipitation forcing. For all turbulent mixing schemes, TC precipitation produces near-surface freshening of about 0.3 psu, which is consistent with previous studies and in situ ocean observations. The influence of precipitation-induced changes to the SST response is more complicated, but generally modifies SSTs by 0.3C. Precipitation forcing creates a dynamical coupling between upper-ocean stratification and current shear that is largely responsible for the heterogeneous response in modeled SSTs.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1038/S43247-021-00259-8", "year": 2021, "title": "Tropical cyclones near landfall can induce their own intensification through feedbacks on radiative forcing", "abstract": "Rapid intensification of near-landfall tropical cyclones is very difficult to predict, and yet has far-reaching consequences due to their disastrous impact to the coastal areas. The focus for improving predictions of rapid intensification has so far been on environmental conditions. Here we use the Coupled-Ocean-Atmosphere-Wave-Sediment Transport Modeling System to simulate tropical cyclones making landfall in South China: Nida (2016), Hato (2107) and Mangkhut (2018). Two smaller storms (Hato and Nida) undergo intensification, which is induced by the storms themselves through their extensive subsidence ahead of the storms, leading to clear skies and strong solar heating of the near-shore sea water over a shallow continental shelf. This heating provides latent heat to the storms, and subsequently intensification occurs. In contrast, such heating does not occur in the larger storm (Mangkhut) due to its widespread cloud cover. This results imply that to improve the prediction of tropical cyclone intensity changes prior to landfall, it is necessary to correctly simulate the short-term evolution of near-shore ocean conditions.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1098/RSPB.2019.2230", "year": 2019, "title": "Deer movement and resource selection during Hurricane Irma: implications for extreme climatic events and wildlife", "abstract": "Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer (Odocoileus virginianus seminolus) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/ATMOS12081036", "year": 2021, "title": "An Observational Study of Aerosols and Tropical Cyclones over the Eastern Atlantic Ocean Basin for Recent Hurricane Seasons", "abstract": "The aerosol vertical distribution in the tropical cyclone (TC) main development region (MDR) during the recent active hurricane seasons (20152018) was investigated using observations from NASAs Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) Satellite. The Total Attenuated Backscatter (TAB) at 532 nm was measured by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP Lidar) onboard CALIPSO which is a polar orbiting satellite that evaluates the role clouds and atmospheric aerosols play in Earths weather, climate and air quality. The TAB was used to illustrate the dispersion and magnitude of the aerosol vertical distribution in the TC-genesis region. A combination of extinction quality flag, cloud fraction, and cloud-aerosol discrimination (CAD) scores were used to filter out the impact of clouds. To better describe the qualitative and quantitative difference of aerosol along the paths of African Easterly Waves (AEWs), the MDR was further divided into two domains from 18 W to 30 W (Domain 1) and 30 W to 45 W (Domain 2), respectively. The distribution of average aerosol concentration from the time of active cyclogenesis was compared and quantified between each case. The resulting observations suggest that there are two distinct layers of aerosols in the vertical profile, a near surface layer from 0.51.75 km and an upper layer at 1.755 km in altitude. A quantification of the total aerosol concentration values indicate domain 2 cases were associated with higher aerosol concentrations than domain 1 cases. The environmental variables such as sea surface temperature (SST), vertical windshear (VWS), and relative humidity (RH) tended to be favorable for genesis to occur. Among all cases in this study, the results suggested tropical cyclone genesis and further development occurred under dust-loaded conditions while the environmental variables were favorable, indicating that dust aerosols may not play a significant role in inhibiting the genesis process of TCs.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/ATMOS13040535", "year": 2022, "title": "What Made the Sustained Intensification of Tropical Cyclone Fani in the Bay of Bengal? An Investigation Using Coupled Atmosphere\u2013Ocean Model", "abstract": "The extremely severe tropical cyclone Fani (25 April5 May 2019) unusually sustained high intensity for a prolonged duration over the Bay of Bengal (BoB). A regional coupled atmosphereocean model was used to investigate the atmospheric and oceanic conditions and processes responsible for the sustained intensification of the tropical cyclone (TC) Fani. The coupled model simulated the track and intensification/weakening stages of the cyclone reasonably well. A reduction in sea surface temperature (by 2 C) and an increase in sea surface salinity due to cyclone-induced upwelling and inertial mixing was noticed in both observations and model. The passage of TC Fani over two geostrophic mesoscale warm-core eddies along the cyclone track was found to supply the necessary energy for the intensification of TC Fani. The sea surface height anomaly and tropical cyclone heat potential (TCHP) were higher during TC Fani than other pre-monsoon cyclones in the BoB. The anomalous TCHP in the warm-core eddy zones (i.e., in excess of >160 kJ cm2) maintained the warm surface temperature and high airsea heat fluxes. The airsea latent heat flux and atmospheric wind shear were favourable for the intensification of the cyclone. The atmospheric moist static energy enhanced up to 360 kJ kg1 with a deep vertical extension in the atmospheric column supporting the further intensification of TC Fani. Therefore, the unusual oceanic TCHP associated with mesoscale eddies, higher latent heat flux, and enhanced moist static energy in the atmosphere contributed to the sustained intensification of TC Fani for a prolonged period in the BoB.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/RS14153634", "year": 2022, "title": "Experimental Proof of Concept for the Hurricane Imaging Radiometer (HIRAD) Measurement of a Hurricane Ocean Surface Wind Speed Field", "abstract": "The objective of the Hurricane Imaging Radiometer (HIRAD) is to produce wide-swath images of hurricane wind and rain fields during a single pass from a high-altitude aircraft. This instrument could be a prototype for the next generation of airborne hurricane remote sensors that operate on NOAA/USAF surveillance flights over named storms and hurricanes. The improved two-dimensional surface wind field measurements provided by the HIRAD approach are crucial to improved forecasts and warnings. For almost a decade, HIRAD has been used in research flights over hurricanes; however, because of various hardware issues, the scientific potential of its measurements has not been fulfilled. This paper presents a reanalysis of HIRAD measurements over Hurricane Gonzalo on 17 October 2014 that demonstrate remarkable results. The basis for this novel approach is to use coincident surface wind speed (WS) and rain rate (RR) measurements from another source to calibrate the HIRAD brightness temperature measurements. As a result, the HIRAD retrievals of WS and RR are in excellent agreement with the accompanying airborne remote sensors and in situ surface wind speed measurements, which validates the HIRAD technique proof of concept.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1038/S41467-021-22304-Y", "year": 2021, "title": "Recent global decrease in the inner-core rain rate of tropical cyclones", "abstract": "Heavy rainfall is one of the major aspects of tropical cyclones (TC) and can cause substantial damages. Here, we show, based on satellite observational rainfall data and numerical model results, that between 1999 and 2018, the rain rate in the outer region of TCs has been increasing, but it has decreased significantly in the inner-core. Globally, the TC rain rate has increased by 8 4% during this period, which is mainly contributed by an increase in rain rate in the TC outer region due to increasing water vapor availability in the atmosphere with rising surface temperature. On the other hand, the rain rate in the inner-core of TCs has decreased by 24 3% during the same period. The decreasing trend in the inner-core rain rate likely results mainly from an increase in atmospheric stability.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1007/S10236-019-01330-X", "year": 2020, "title": "A coupled model analyses on the interaction between oceanic eddies and tropical cyclones over the Bay of Bengal", "abstract": "The Bay of Bengal (BOB) region of Indian Ocean is affected by numerous tropical cyclones during pre- and post-monsoon seasons when various eddies are generated in the central and western bay. Here, numerical simulations of few tropical cyclones (Aila, Laila, Phailin, Hudhud and Madi) that occurred in different seasons are carried out using an ocean atmosphere coupled numerical model, consisting of Weather Research and Forecasting (WRF) and Regional Ocean Modeling Systems (ROMS), to analyse the influence of eddies on tropical cyclone intensifications over the bay. The model is able to track the tropical cyclones with less error, while the central pressure and wind speed are underestimated. Also, the coupling process steer the cyclones to the observed track compared to standalone WRF model. The variations in simulated sea surface temperature and salinity are in agreement with the satellite and in situ measurements. During the passage of Phailin and Hudhud over the eddies, the cyclones intensified almost twice of their initial central pressure and wind (before interacting with eddies), which the model captured very well. The eddy feedback factor, which estimate the influence of warm eddies on tropical cyclones, is about 152% for Phailin and 90% for Hudhud. In the case of the pre-monsoon cyclones, Aila and Laila, the eddy feedback factor is estimated up to 36% and 21%, respectively. Madi cyclone lost its intensification up to 80% because of its interaction with a cold eddy. These predictions are comparable with that of the observations during the cyclone passage. Also it is noted that the warm eddy regions resulted in the maximum transfer of latent heat resulting in strong intensifications of the cyclones. Our study reveals that the eddies play an important role in the intensification and dissipation of BOB cyclones and understanding their nature can help in estimating the track and intensity of cyclones.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.17159/SAJS.2021/7911", "year": 2021, "title": "Evaluating South African Weather Service information on Idai tropical cyclone and KwaZulu- Natal flood events", "abstract": "Severe weather events associated with strong winds and flooding can cause fatalities, injuries and damage to property. Detailed and accurate weather forecasts that are issued and communicated timeously, and actioned upon, can reduce the impact of these events. The responsibility to provide such forecasts usually lies with government departments or state-owned entities; in South Africa that responsibility lies with the South African Weather Service (SAWS). SAWS is also a regional specialised meteorological centre and therefore provides weather information to meteorological services within the Southern African Development Community (SADC). We evaluated SAWS weather information using near real-time observations and models on the nowcasting to short-range forecasting timescales during two extreme events. These are the Idai tropical cyclone in March 2019 which impacted Mozambique, Zimbabwe and Malawi resulting in over 1000 deaths, and the floods over the KwaZulu-Natal (KZN) province in April 2019 that caused over 70 deaths. Our results show that weather models gave an indication of these systems in advance, with warnings issued at least 2 days in advance in the case of Idai and 1 day in advance for the KZN floods. Nowcasting systems were also in place for detailed warnings to be provided as events progressed. Shortcomings in model simulations were shown, in particular on locating the KZN flood event properly and over/underestimation of the event. The impacts experienced during the two events indicate that more needs to be done to increase weather awareness, and build disaster risk management systems, including disaster preparedness and risk reduction.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JAS-D-16-0018.1", "year": 2017, "title": "Dynamics and predictability of the intensification of Hurricane Edouard (2014)", "abstract": "Abstract The dynamics and predictability of the intensification of Hurricane Edouard (2014) are explored through a 60-member convection-permitting ensemble initialized with an ensemble Kalman filter that assimilates dropsondes collected during NASAs Hurricane and Severe Storm Sentinel (HS3) investigation. The 126-h forecasts are initialized when Edouard was designated as a tropical depression and include Edouards nearrapid intensification (RI) from a tropical storm to a strong category-2 hurricane. Although the deterministic forecast was very successful and many members correctly forecasted Edouards intensification, there was significant spread in the timing of intensification among the members of the ensemble. Utilizing composite groups created according to the near-RI-onset times of the members, it is shown that, for increasing magnitudes of deep-layer shear, RI onset is increasingly delayed; intensification will not occur once a critical shear threshold is exceeded. Although the timing of intensification varies by as much as 48 h, a decrease in shear is observed across the intensifying composite groups ~612 h prior to RI. This decrease in shear is accompanied by a reduction in vortex tilt, as the precession and subsequent alignment process begins ~2448 h prior to RI. Sensitivity experiments reveal that some of the variation in RI timing can be attributed to differences in initial intensity, as the earliest-developing members have the strongest initial vortices regardless of their environment. Significant sensitivity and limited predictability exists for members with weaker initial vortices and/or that are embedded in less conducive environments, under which the randomness of moist convective processes and minute initial differences distant from the surface center can produce divergent forecasts.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1038/S41598-018-34343-5", "year": 2018, "title": "The roles of climate change and climate variability in the 2017 Atlantic hurricane season", "abstract": "The 2017 Atlantic hurricane season was extremely active with six major hurricanes, the third most on record. The sea-surface temperatures (SSTs) over the eastern Main Development Region (EMDR), where many tropical cyclones (TCs) developed during active months of August/September, were ~0.96 C above the 19012017 average (warmest on record): about ~0.42 C from a long-term upward trend and the rest (~80%) attributed to the Atlantic Meridional Mode (AMM). The contribution to the SST from the North Atlantic Oscillation (NAO) over the EMDR was a weak warming, while that from El NinoSouthern Oscillation (ENSO) was negligible. Nevertheless, ENSO, the NAO, and the AMM all contributed to favorable wind shear conditions, while the AMM also produced enhanced atmospheric instability. Compared with the strong hurricane years of 2005/2010, the ocean heat content (OHC) during 2017 was larger across the tropics, with higher SST anomalies over the EMDR and Caribbean Sea. On the other hand, the dynamical/thermodynamical atmospheric conditions, while favorable for enhanced TC activity, were less prominent than in 2005/2010 across the tropics. The results suggest that unusually warm SST in the EMDR together with the long fetch of the resulting storms in the presence of record-breaking OHC may be key factors in driving the strong TC activity in 2017.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JCLI-D-21-0747.1", "year": 2022, "title": "Reduced Sea Ice Enhances Intensification of Winter Storms over the Arctic Ocean", "abstract": "Abstract The ideal environment for extratropical cyclone development includes strong vertical shear of horizontal wind and low static stability in the atmosphere. Arctic sea ice loss enhances the upward flux of energy to the lower atmosphere, reducing static stability. This suggests that Arctic sea ice loss may facilitate more intense storms over the Arctic Ocean. However, prior research into this possibility has yielded mixed results with uncertain cause and effect. This work has been limited either in scope (focusing on a few case studies) or resolution (focusing on seasonal averages). In this study, we extend this body of research by comparing the intensification rate and maximum intensity of individual cyclones to local sea ice anomalies. We find robust evidence that reduced sea ice in winter (DecemberMarch) strengthens Arctic cyclones by enhancing the surface turbulent heat fluxes and lessening static stability while also strengthening vertical shear of horizontal wind. We find weaker evidence for this connection in spring (AprilJune). In both seasons, lower sea ice concentration also enhances cyclone-associated precipitation. Although reduced sea ice also weakens static stability in September/October (when sea ice loss has been especially acute), this does not translate to stronger storms because of coincident weakening of wind shear. Sea ice anomalies also have little or no connection to cyclone-associated precipitation in these months. Therefore, future sea ice reductions (e.g., related to delayed autumn freeze-up) will likely enhance Arctic cyclone intensification in winter and spring, but this relationship is sensitive to simultaneous connections between sea ice and wind shear. Significance Statement Sea ice is a barrier between the ocean and atmosphere, limiting the exchange of energy between them. As the amount of sea ice in the Arctic Ocean declines, the ocean can transfer more heat to the atmosphere above in fall and winter. It is theorized that this extra energy may help intensify storms that pass through the Arctic. We examine individual storms over the Arctic Ocean and what sea ice conditions they experience as they develop. We find that storms intensify more when sea ice is lower than normal in the winter season only. This relationship may contribute to stronger Arctic winter storms in the future, including heavier precipitation and stronger winds (which can enhance wave heights and coastal erosion).", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/ASL.1125", "year": 2022, "title": "Recent decrease in inner-core rain rate of tropical cyclones over the western North Pacific", "abstract": "AbstractThe tendency in tropical cyclone (TC) rainfall is of great concern due to its remarkable contribution to global precipitation and extreme rainfall events. This study finds a decreasing trend in TC innercore rain rate over the western North Pacific (WNP) from 1998 to 2019. This basinwide trend is mainly induced by the decreasing TC innercore rain rates over the region west of 150E, while it is seldom linked to the changes in the distribution of TC occurrence. The maximum decreases in TC innercore rain rate are observed over the offshore areas along the coastlines of East Asia. Further analysis reveals that the change in atmospheric stability, referred to as a dominant environmental contributor to basinwide TC innercore rain rate decreases shown in previous studies, only has a primary impact over the northern South China Sea. By comparison, there is a positive correlation between the variations of the aerosol optical depth and TC innercore rain rate over the midlatitude regions extending from the East China Sea to Japan. Our result highlights the linkage of the recent decreasing trends in aerosol optical depth and TC innercore rain rate over the WNP.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1007/S00382-022-06627-0", "year": 2022, "title": "The earlier end of the tropical cyclone season over the Western North Pacific by environmental cyclogenesis factors", "abstract": "Several of the best track datasets reveal the earlier end of the tropical cyclone (TC) season over the main WNP (the east of the Philippine Islands) from 1980 to 2019, especially by the date of the upper decile of the storm days (constructed by adding one to each date if any TC exists). The enhanced vertical wind shear (VWS) during the late season (October and November) is consistent with this earlier end of the TC season. In October, the enhanced VWS is the result of the increased zonal and meridional shears, which are affected by the earlier circulation transition of the East Asian summer monsoon recessed and winter monsoon onset during late October. During November, the zonal wind shear dominates the enhanced VWS, which vertically is the opposite trend of air temperature below and above the tropopause and the meridionally opposite trend of air temperature in the north and south of 30N. The opposite air temperature trends induce the thermal wind balance, which causes enhanced westerlies in the mid-latitudes and strong zonal shear. Three pathways increase VWS in the late season over the WNP, leading to the earlier end of the TC season. The strong impact of VWS limits TC formation, although the ambient warming underlying the surface (supports a broader and stronger potential intensity). The effect of the thermodynamical parameter, depending on relative humidity at the low and middle troposphere, is uncertain because of the inconsistent and weak trends in October between ERA5 and MERRA-2, but they both become unfavorable to TC genesis during November. The practically important meaning of the VWS for the TC season provides a possibility for future projections of the TC season.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JCLI-D-20-0517.1", "year": 2021, "title": "Large-scale state and evolution of the atmosphere and ocean during PISTON 2018", "abstract": "Abstract The Propagation of Intraseasonal Tropical Oscillations (PISTON) experiment conducted a field campaign in AugustOctober 2018. The R/V Thomas G. Thompson made two cruises in the western North Pacific region north of Palau and east of the Philippines. Using select field observations and global observational and reanalysis datasets, this study describes the large-scale state and evolution of the atmosphere and ocean during these cruises. Intraseasonal variability was weak during the field program, except for a period of suppressed convection in October. Tropical cyclone activity, on the other hand, was strong. Variability at the ship location was characterized by periods of low-level easterly atmospheric flow with embedded westward propagating synoptic-scale atmospheric disturbances, punctuated by periods of strong low-level westerly winds that were both connected to the Asian monsoon westerlies and associated with tropical cyclones. In the most dramatic case, westerlies persisted for days during and after tropical cyclone Jebi had passed to the north of the ship. In these periods, the sea surface temperature was reduced by a couple of degrees by both wind mixing and net surface heat fluxes that were strongly (~200 W m2) out of the ocean, due to both large latent heat flux and cloud shading associated with widespread deep convection. Underway conductivitytemperature transects showed dramatic cooling and deepening of the ocean mixed layer and erosion of the barrier layer after the passage of Typhoon Mangkhut due to entrainment of cooler water from below. Strong zonal currents observed over at least the upper 400 m were likely related to the generation and propagation of near-inertial currents.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1038/S41467-022-32779-Y", "year": 2022, "title": "Natural and anthropogenic contributions to the hurricane drought of the 1970s\u20131980s", "abstract": "Atlantic hurricane activity experienced a pronounced lull during the 1970s and 1980s. The current explanation that anthropogenic aerosol radiative forcing cooled the sea surface locally fails to capture the magnitude of this large decrease in activity. To explain this hurricane drought, we propose that the radiative effects of sulfate aerosols from Europe and North-America decreased precipitation in the Sahara-Sahel region, leading to an enhancement of dust regional emissions and transport over the Atlantic. This dust in turn enhanced the local decrease of sea-surface temperature and of hurricane activity. Here, we show that dust emissions from the Sahara peaked in phase with regional sulfate aerosol optical thickness and Sahel drought conditions, and that dust optical depth variations alone can explain nearly half of the sea-surface temperature depression in the 1970s and 1980s.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/WEA.3746", "year": 2020, "title": "Super typhoons Hato (1713) and Mangkhut (1822), partII: challenges in", "abstract": "This is the second paper of a two-part series about Super Typhoons Hato (1713) and Mangkhut (1822), which hit Hong Kong successively in 2017 and 2018, respectively, and necessitated the issuance of the highest tropical cyclone warning signal. While their maximum intensity and wind structure are analysed in Part I, this paper covers the challenges in forecasting and early warning of the storms. The actual and predicted tropical cyclone track, intensity and storm surge in Hong Kong and their associated storm surge risk are reviewed. Experience in early warning and disaster risk reduction is also shared in this paper.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1088/1748-9326/AB9BE2", "year": 2020, "title": "Dependence of tropical cyclone damage on maximum wind speed and socioeconomic factors", "abstract": "Abstract\r\n Tropical cyclones (TCs) have devastating impacts and are responsible for significant damage. Consequently, for TC-induced direct economic loss (DEL) attribution all factors associated with risk (i.e. hazard, exposure and vulnerability) must be examined. This research quantifies the relationship between TC-induced DELs and maximum wind speed, asset value and Gross Domestic Product (GDP) per capita using a regression model with TC records from 2000 to 2015 for Chinas mainland area. The coefficient of the maximum wind speed term indicates that a doubling of the maximum wind speed increases DELs by 225% [97%, 435%] when the other two variables are held constant. The coefficient of the asset value term indicates that a doubling of asset value exposed to TCs increases DELs by 79% [58%, 103%]; thus, if hazard and vulnerability are assumed to be constant in the future, then a dramatic escalation in TC-induced DELs will occur given the increase in asset value, suggesting that TC-prone areas with rapid urbanization and wealth accumulation will inevitably be subject to higher risk. Reducing the asset value exposure via land-use planning, for example, is important for decreasing TC risk. The coefficient of GDP per capita term indicates that a doubling in GDP per capita could decrease DELs by 54% [39%, 66%]. Because accumulated assets constantly increase peoples demand for improved security, stakeholders must invest in risk identification, early warning systems, emergency management and other effective prevention measures with increasing income to reduce vulnerability. This research aims to quantitatively connect TC risk (expected DELs, specifically) to physical and socioeconomic drivers and emphasizes how human dimensions could contribute to TC risk. Moreover, the model can be used to estimate TC risk under climate change and future socioeconomic development in the context of China.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2018JD029095", "year": 2018, "title": "Polar Jet Associated Circulation Triggered a Saharan Cyclone and Derived", "abstract": "In this study, we identify a new mechanism by which dust aerosols travel over long distances across the eastern side of the North Atlantic Ocean toward the Arctic. The meandering polar jet was at the origin of both dust emission through cyclogenesis over Northwest Africa and poleward transport of the uplifted dust toward the Arctic, through cut-off circulation. The dust emission was associated with an intense Saharan cyclone that formed over Northwest Africa in early April 2011. The formation of the cyclone was caused by the intrusion into subtropics, of a high-latitude-upper-level trough, linked to the meandering polar jet. The trough initiated cyclogenesis over Northwest Africa after orographic blocking by the Anti-Atlas Mountains. The still meandering polar jet led to the formation of a cut-off low further south with which the Saharan dust-cyclone merged 2 days later and moved northward with the main stream. Beside satellite observations, a simulation at high resolution was performed using the prognostic-dust permitting model MesoNH. The total dust load carried during this event to areas located north of 40 N was estimated by the model to be 38 Tg and dust deposition was estimated to be 1.3 Tg. The Saharan dust reaching Greenland was accompanied by warm and moist air masses that caused a rise in surface temperature of about 10C for more than 3 consecutive days over the southeastern Greenland. Ice melt over this area of Greenland was detected in the brightness temperature observations.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2021GL095451", "year": 2021, "title": "Influence of vertical wind shear on the ocean response to tropical cyclones based on satellite observations", "abstract": "We here investigate the effects of tropical cyclone (TC)-induced rainfall asymmetries driven by vertical wind shear on ocean salinity and temperature response to TCs using satellite and in situ observations. On average, TCs tend to initially freshen the ocean surface due to heavy rainfall and subsequently salinity from upwelling and vertical mixing, with strongest surface salinification on the right-hand side of the Northern Hemisphere TCs. The direction of shear has been found to control the location of maximum TC rainfall, resulting in more freshwater accumulation on the right-hand side of the right-sheared storms. The accumulated freshwater strengthens salinity stratification and inhibits right-side biased vertical mixing, reducing subsequent surface salinification by 0.15-0.3 psu and slightly suppressing the surface cooling by about 0.15\u00b0C, relative to left-sheared storms. Thus, the directionality of shear can impact ocean-TC coupling.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.FORECO.2020.118243", "year": 2020, "title": "Satellite observations of forest resilience to hurricanes along the northern Gulf of Mexico", "abstract": "As one of the most destructive natural disasters, hurricanes pose a great threat to forest ecosystems, particularly in the coastal areas. A better understanding of forest resilience to hurricane disturbances is essential for reducing hazard risks as well as sustaining forests in a time of increasing climate disasters. Although hurricane-induced forest damage has been extensively studied at both local and regional levels, the lack of large-scale assessment of post-hurricane recovery still limits our understanding of forest resilience to hurricane disturbances. In this study, we utilized four remotely sensed vegetation indices (VIs), including the normalized difference infrared index (NDII), enhanced vegetation index (EVI), leaf area index (LAI), and solar-induced chlorophyll fluorescence (SIF), to examine the forest resilience to hurricanes of different strengths by quantifying the resistance, net change, and recovery of the forest after hurricanes that made landfall along the northern Gulf of Mexico from 2001 to 2015. The results revealed that the NDII was superior in monitoring the large-scale forest resilience. SIF exhibited a performance similar to that of the EVI. Wind speed was found to be the leading factor affecting forest damage and post-hurricane recovery. The impacted forest canopy began to recover approximately one month after the landfall. Woody wetlands exhibited less VI reduction and shorter recovery time than evergreen forests for the same category of hurricanes. For regions dominated by evergreen forests, NDII values lower than the multi-year average were observed across all seasons during the year after being impacted by a major hurricane. The widespread drought of 2006/2007 has aggravated the VI decrease and substantially extended the recovery period after hurricanes Ivan and Katrina. Overall, our findings derived from satellite observations provide essential information for understanding forest resilience to hurricanes as well as implementing efficient post-hurricane forest restoration.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105883", "year": 2022, "title": "The impacts of multi-physics parameterization on forecasting heavy rainfall induced by weak landfalling Typhoon Rumbia (2018)", "abstract": "The weak and sustained tropical cyclone (TC) Rumbia (2018) and its associated heavy precipitation after landfall are simulated by the Weather Research and Forecasting model using three microphysics parameterizations (MP) and two planetary boundary layer (PBL) schemes. Key factors regulating the heavy rainfall distribution of landed TC at three stages (landfall, inland slow-moving and recurving stage) and their sensitivities to multi-physics parameterizations are examined. Results show that heavy rainfall distribution is largely regulated by the intensity of TC itself at landfall, but more affected by environmental factors at the two inland stages, including the environmental vertical wind shear, the associated upper-level wind divergence and low-level moisture convergence. Different MP and PBL schemes mainly affect the simulation of TC thermodynamic structure and key environmental factors, leading to their different forecast skills at three stages. Specifically, the Yonsei University (YSU) PBL scheme systematically outperforms the Mellor-Yamada-Nakanishi-Niino (MYNN) scheme in simulating stronger TC and heavy rainfall intensity. With the advantageous YSU PBL scheme, the Ferrier MP scheme only shows a slight advantage in simulating the intensity of TC and heavy rainfall at landfall. However, the WRF single-moment 6-class (WSM6) and Thompson scheme produce more graupel or snow, and better simulate the key environmental factors, showing their respective advantages in simulating the heavy rainfall structure and location at the two inland stages. This implies that the use of nonlocal YSU PBL scheme and the MP schemes with sophisticated ice processes shows superiority in simulating the postlandfall heavy rainfall induced by weak TCs.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.JENVMAN.2022.114950", "year": 2022, "title": "Earth observation and geospatial data can predict the relative distribution of village level poverty in the Sundarban Biosphere Reserve, India", "abstract": "There is increasing interest in leveraging Earth Observation (EO) and geospatial data to predict and map aspects of socioeconomic conditions to support survey and census activities. This is particularly relevant for the frequent monitoring required to assess progress towards the UNs' Sustainable Development Goals (SDGs). The Sundarban Biosphere Reserve (SBR) is a region of international ecological importance, containing the Indian portion of the world's largest mangrove forest. The region is densely populated and home to over 4.4 million people, many living in chronic poverty with a strong dependence on nature-based rural livelihoods. Such livelihoods are vulnerable to frequent natural hazards including cyclone landfall and storm surges. In this study we examine associations between environmental variables derived from EO and geospatial data with a village level multidimensional poverty metric using random forest machine learning, to provide evidence in support of policy formulation in the field of poverty reduction. We find that environmental variables can predict up to 78% of the relative distribution of the poorest villages within the SBR. Exposure to cyclone hazard was the most important variable for prediction of poverty. The poorest villages were associated with relatively small areas of rural settlement (50%) and moderate to high cyclone hazard. The poorest villages were also associated with less productive agricultural land than the wealthiest. Analysis suggests villages with access to more diverse livelihood options, and a smaller dependence on agriculture may be more resilient to cyclone hazard. This study contributes to the understanding of poverty-environment dynamics within Low-and middle-income countries and the associations found can inform policy linked to socio-environmental scenarios within the SBR and potentially support monitoring of work towards SDG1 (No Poverty) across the region.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.WACE.2021.100366", "year": 2021, "title": "Comparative climatology of outer tropical cyclone size using radial wind profiles", "abstract": "In this study was performed a comparative climatology of outer tropical cyclone (TCs) size using radial wind profiles. A wind speed of 2 ms1 (4 kt) was taken as the threshold to define the TC size. The method proposed by Willoughby et al. (2006) (W06) to determine the wind profile showed the least variance and the smallest coefficient of variation of all profiles. W06 correctly described the radial wind structure of storms such as Hurricane Irma (2017) and Cyclone Giri (2010), compared with the European Centre for Medium-Range Weather Forecasts ERA-5 reanalysis data. Thus, W06 was used to develop the climatological TC size (TCSize) database. It was found that the tropical cyclones are largest when the maximum wind speed ranges between 20 and 40 ms1 and they most frequently reach a size between 700 and 800 km. The TCs exhibit their maximum size when they are in extratropical latitudes, while the smallest are observed in the low latitudes of both hemispheres. The global mean size is 748.7 km with a 95% confidence interval of [748.2,749.2] km. Median storm size is largest in the North Atlantic basin and smallest in the North Indian Ocean. The method proposed here is designed to be an objective metric that can be quickly applied to any TC when its position, maximum wind speed, and minimum central pressure are known. As a result, a TCSize database was created for all ocean basins, which could be useful for many applications, including different risk analyses.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/JGRD.50718", "year": 2013, "title": "Multiple satellite observations of cloud cover in extratropical cyclones", "abstract": "cloud observations from NASA Moderate Resolution Imaging Spectroradiometer, Multiangle Imaging Spectroradiometer, and CloudSat-CALIPSO, composites of cloud fraction in southern and northern hemisphere extratropical cyclones are obtained for cold and warm seasons between 2006 and 2010, to assess differences between these three data sets, and between summer and winter cyclones. In both hemispheres and seasons, over the open ocean, the cyclone-centered cloud fraction composites agree within 5% across the three data sets, but behind the cold fronts, or over sea ice and land, the differences are much larger. To supplement the data set comparison and learn more about the cyclones, we also examine the differences in cloud fraction between cold and warm season for each data set. The difference in cloud fraction between cold and warm season southern hemisphere cyclones is small for all three data sets, but of the same order of magnitude as the differences between the data sets. The cold-warm season contrast in northern hemisphere cyclone cloud fractions is similar for all three data sets: in the warm sector, the cold season cloud fractions are lower close to the low, but larger on the equator edge than their warm season counterparts. This seasonal contrast in cloud fraction within the cyclones warm sector seems to be related to the seasonal differences in moisture flux within the cyclones. Our analysis suggests that the three different data sets can all be used confidently when studying the warm sector and warm frontal zone of extratropical cyclones but caution should be exerted when studying clouds in the cold sector.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JAMC-D-18-0034.1", "year": 2018, "title": "Spatial characteristics of rain fields associated with tropical cyclones landfalling over the western Gulf of Mexico and Caribbean Sea", "abstract": "Abstract The western Gulf Coast and Caribbean coast are regions that are highly vulnerable to precipitation associated with tropical cyclones (TCs). Defining the spatial dimensions of TC rain fields helps determine the timing and duration of rainfall for a given location. Therefore, this study measured the area, dispersion, and displacement of light and moderate rain fields associated with 35 TCs making landfalls in this region and explored conditions contributing to their spatial variability. The spatial patterns of satellite-estimated rain rates are determined through hot spot analysis. Rainfall coverage is largest as TCs approach the western Caribbean coast, and smaller as TCs move over the Gulf of Mexico (GM) after making landfall over the Yucatan Peninsula. The rain fields are displaced eastward and northward over the western and central Caribbean Sea and the central GM. Rainfall fields have more displacement toward the west and south, which is over land, when TCs move over the southern GM, possibly as a result of the influence of Central American gyres. The area and dispersion of rainfall are significantly correlated with storm intensity and total precipitable water. The displacement of rainfall is significantly correlated with vertical wind shear. Over the Bay of Campeche, TC precipitation extends westward, which may be related to the convergence of moisture above the boundary layer from the Pacific Ocean and near-surface convergence enhanced by land. Additionally, half of the storms produce rainfall over land about 48 h before landfall. TCs may produce light rainfall over land for more than 72 h in this region.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/SE-9-1299-2018", "year": 2018, "title": "Failure criteria for porous dome rocks and lavas: a study of Mt. Unzen, Japan", "abstract": "Abstract. The strength and macroscopic deformation mode (brittle vs. ductile) of rocks is generally related to the porosity and pressure conditions, with occasional considerations of strain rate. At high temperature, molten rocks abide by Maxwell's viscoelasticity and their deformation mode is generally defined by strain rate or reciprocally by comparing the relaxation timescale of the material (for a given condition) to the observation timescale a dimensionless ratio known as the Deborah (De) number. Volcanic materials are extremely heterogeneous, with variable concentrations of crystals, glassmelt, and vesicles (of different sizes), and a complete description of the conditions leading to flow or rupture as a function of temperature, stress and strain rate (or timescale of observation) eludes us. Here, we examined the conditions which lead to the macroscopic failure of variably vesicular (0.090.35), crystal-rich ( 75 vol %), pristine and altered dome rocks (at ambient temperature) and lavas (at 900 C) from Mt. Unzen volcano, Japan. We found that the strength of the dome rocks decreases with porosity and is commonly independent of strain rate; when comparing pristine and altered rocks, we found that the precipitation of secondary mineral phases in the original pore space caused minor strengthening. The strength of the lavas (at 900 C) also decreases with porosity. Importantly, the results demonstrate that these dome rocks are weaker at ambient temperatures than when heated and deformed at 900 C (for a given strain rate resulting in brittle behaviour). Thermal stressing (by heating and cooling a rock up to 900 C at a rate of 4 C min1, before testing its strength at ambient temperature) was found not to affect the strength of rocks.In the magmatic state (900 C), the rheology of the dome lavas is strongly strain rate dependent. Under conditions of low experimental strain rate ( 104 s1), ductile deformation dominated (i.e. the material sustained substantial, pervasive deformation) and displayed a non-Newtonian shear thinning behaviour. In this regime, the apparent viscosities of the dome lavas were found to be essentially equivalent, independent of vesicularity, likely due to the lack of pore pressurisation and efficient pore collapse during shear. At high experimental strain rates ( 104 s1) the lavas displayed an increasingly brittle response (i.e. deformation resulted in failure along localised faults); we observed an increase in strength and a decrease in strain to failure as a function of strain rate. To constrain the conditions leading to failure of the lavas, we analysed and compared the critical Deborah number at failure (Dec) of these lavas to that of pure melt (Demelt = 103102; Webb and Dingwell, 1990). We found that the presence of crystals decreases Dec to between 6.6104 and 1104. The vesicularity (), which dictates the strength of lavas, further controls Dec following a linear trend. We discuss the implications of these findings for the case of magma ascent and lava dome structural stability.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2022GL098626", "year": 2022, "title": "The Mesoscale Gravity Wave Response to the 2022 Tonga Volcanic Eruption: AIRS and MLS Satellite Observations and Source Backtracing", "abstract": "On 15 January 2022, the Hunga Tonga-Hunga Ha'apai volcano erupted violently. This exceptional event excited a manifold of atmospheric waves. Here, we focus on the mesoscale part of the wave spectrum. About 8.5 hr after the eruption a strong atmospheric gravity wave (GW) was observed in the stratosphere by the satellite instruments Atmospheric Infrared Sounder (AIRS) and Microwave Limb Sounder (MLS) in the vicinity of Tonga. By ray-tracing, we confirm the eruption as the source of this GW event. We determine the wave characteristics of the GW in terms of horizontal and vertical wavelengths and GW momentum flux. The strength of the GW is compared to the usual Southern Hemisphere flux values during this week. The event is comparable to the strongest convective events considering MLS, and exceptionally strong considering AIRS, which observes faster waves only.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ESSD-12-3139-2020", "year": 2020, "title": "A multi-sensor satellite-based archive of the largest SO2 volcanic eruptions since 2006", "abstract": "Abstract. We present a multi-sensor archive collecting spatial and temporal information about volcanic SO2 clouds generated by the 11 largest eruptions of this century. The detection and monitoring of volcanic clouds are an important topic for aviation management, climate issues and weather forecasts. Several studies focusing on single eruptive events exist, but no archive available at the moment combines quantitative data from as many instruments. We archived and collocated the SO2 vertical column density estimations from three different satellite instruments (AIRS, IASI and GOME-2), atmospheric parameters as vertical profiles from the Global Navigation Satellite Systems (GNSS) Radio Occultations (RO), and the cloud-top height and aerosol type from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). Additionally, we provide information about the cloud-top height from three different algorithms and the atmospheric anomaly due to the presence of the cloud. The dataset is gathering 206 d of SO2 data, collocated with 44 180 backscatter profiles and 64 764 radio occultation profiles. The modular structure of the archive allows an easy collocation of the datasets according to the users' needs, and the cross-comparison of the datasets shows different consistency of the parameters estimated with different sensors and algorithms, according to the sensitivity and resolution of the instruments. The data described here are published with a DOI at https://doi.org/10.5880/fidgeo.2020.016 (Tournigand et al., 2020a).", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021JD035548", "year": 2022, "title": "What contributes to the inter\u2010annual variability in tropical lower stratospheric temperatures?", "abstract": "The inter-annual variability in mid and lower stratospheric temperatures for the period 1984-2019 is decomposed into dynamical and radiative contributions using a radiative calculation perturbed with changes in dynamical heating, trace gases and aerosol optical depth. The temperature timeseries obtained is highly correlated with the de-seasonalized ERA5 temperature (r2 > 0.6 in the region 15 to 70 hPa, 1992 to 2019-after the Pinatubo volcanic eruption). Ozone and dynamical heating contributions are found to be equally important, with water vapor, stratospheric aerosols, and carbon dioxide playing smaller roles. Prominent aspects of the temperature timeseries are closely reproduced, including the 1991 Pinatubo volcanic eruption, the year-2000 water vapor drop, and the 2016 Quasi-biennial oscillation (QBO) disruption. Below 20 hPa, ozone is primarily controlled by transport and is positively correlated to the upwelling. This ozone-transport feedback acts to increase the temperature response to a change in upwelling by providing an additional ozone-induced radiative temperature change. This can be quantified as an enhancement of the dynamical heating of about 20% at 70 hPa. A Principal Oscillation Pattern (POP) analysis is used to estimate the contribution of the ozone QBO (\u00b11 K at 70 hPa). The non-QBO ozone variability is also shown to be significant. Using the QBO leading POP timeseries as representative of the regular QBO signal, the QBO 2016 disruption is shown to have an anomalously large radiative impact on temperature due to the ozone change (> 3 K$ > 3\\hspace*{.5em}\\mathrm{K}$ at 70 hPa).", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2019GL084396", "year": 2019, "title": "Quantifying Stratospheric Temperature Signals and Climate Imprints From", "abstract": "Small volcanic eruptions and their effects have recently come into research focus. While large eruptions are known to strongly affect stratospheric temperature, the impacts of smaller eruptions are hard to quantify because their signals are masked by natural variability. Here, we quantify the temperature signals from small volcanic eruptions between 2002 and 2016 using new vertically resolved aerosol data and precise temperature observations from radio occultation. We find characteristic space-time signals that can be associated with specific eruptions. In the lower stratosphere, robust warming signals are observed, while in the midstratosphere also cooling signals of some eruptions appear. We find that the volcanic contribution to the temperature trend is up to 20%, depending on latitude and altitude. We conclude that detailed knowledge of the vertical structure of volcanic temperature impacts is crucial for comprehensive trend analysis in order to separate natural from anthropogenic temperature changes.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.07.303", "year": 2019, "title": "Sediment connectivity changes in an Andean catchment affected by volcanic eruption", "abstract": "River systems are continuously affected by multiple natural and anthropogenic phenomena. Among major natural disturbances, volcanic eruptions have the capability to overthrow the forms and to modify dramatically the morphological setting and sediment connectivity of the system. Moreover, the input of sediments in the channel network can lead to active channel widening, bed aggradation and river scouring, which in turn may affect downstream human settlements. In this context, the present research aims to investigate sediment connectivity by means of a geomorphometric index in a catchment affected by an explosive volcanic eruption in order to assess its variation before and after the disturbance. We developed a workflow exploiting the use of open source data (i.e., Global Digital Elevation Models, satellite imagery) to represent the impedance to the sediment fluxes and to apply the Index of Connectivity (IC) in this context characterized by the lack of high-resolution topographic data. The study area is the Blanco River basin, southern Chile, which was heavily affected by the eruption of Chaiten volcano (20082009) that caused the partial destruction of the forest and the profound alteration of Blanco River's morphology. The application of the IC on different land cover scenarios, derived by combining field observations and satellite image classification techniques, showed an increase in sediment connectivity after the volcanic eruption. In addition, the results highlighted different patterns of connectivity according to the expansion of the active channel induced by the massive input of pyroclastic material. The approach proposed in this study case offers a methodology to investigate sediment connectivity in a river catchment affected by natural disturbance where high-resolution data are not available. The results of the study help to improve knowledge on the effect of volcanic eruptions in the hydrologic catchment and to improve watershed management strategies in such kind of environment.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JAEROSCI.2018.10.006", "year": 2019, "title": "Optical depths and vertical profiles of stratospheric aerosol based on multi-year polarization measurements of the twilight sky", "abstract": "The method of detection of light scattering on stratospheric aerosol particles on the twilight sky background is considered. It is based on the data on sky intensity and polarization in the solar vertical at zenith distances of up to 50 from the sunset till the moment of the Sun depression to 8 below the horizon. The measurements conducted in central Russia since 2011 had shown the negative trend of stratospheric aerosol content, this can be related with the relaxation of the stratosphere after the number of volcanic eruptions during the first decade of XXI century.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS12040728", "year": 2020, "title": "Infrasound Observations of Atmospheric Disturbances Due to a Sequence of Explosive Eruptions at Mt. Shinmoedake in Japan on March 2018", "abstract": "Thirty infrasound sensors have been operated over Japan since 2015. We developed the irregular array data processing in order to detect and estimate the parameters of the arrival source waves by using infrasound data related to the sequence of the volcanic eruption at Mt. Shinmoedake in March 2018. We found that the apparent velocity at the ground was equal to the acoustic velocity at particular reflection levels. The results were confirmed through a comparison of the findings of the apparent velocity with a wave propagation simulation on the basis of the azimuth, infrasound time arrivals, and the state of the atmospheric background using global atmospheric models. In addition, simple ideas for estimating horizontal wind speeds at certain atmospheric altitudes based on infrasound observation data and their validation and comparison were presented. The calculated upper wind speed and wind observed by radiosonde measurements were found to have a qualitative agreement. Propagation modeling for these events estimated celerities in the propagation direction to the sensors that were consistent with the tropospheric and stratospheric ducting. This study could inspire writers, in particular, and readers, in general, to take advantage of the benefits of infrasound wave remote-sensing for the study of the Earths atmospheric dynamics.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1175/JAS-D-22-0078.1", "year": 2022, "title": "First Detection of the Pekeris Internal Global Atmospheric Resonance: Evidence from the 2022 Tonga Eruption and from Global Reanalysis Data", "abstract": "Abstract We used observations and model simulation to examine the atmospheric pulses that dominate the far field in the hours after the January 2022 Tonga eruption. We analyzed radiance observations taken from the Himawari-8 geostationary satellite and showed that both a Lamb wave front with the expected horizontal phase speed 315 m s1 and a distinct front with phase speed 245 m s1 can be detected. The slower phase speed is consistent with that expected for the global internal resonant mode that had been proposed by Pekeris in 1937 and in other idealized theoretical studies over the past century, but which had never been detected in the atmosphere. A simulation of the eruption aftermath was performed with a high-resolution atmospheric general circulation model. A hot anomaly over the volcano location was introduced instantaneously to the model fields and the model was integrated for another 12 h. This produced a simulated wave pulse that, in the far field, agreed reasonably well with barograph observations of the Lamb wave. The model results also showed the presence of the slower pulse and that this disturbance had a vertical structure with a 180 phase shift in the stratosphere, in agreement with the theoretical prediction for the internal resonant mode. An implication is that the continuously ringing Lamb wave global normal modes that have been seen in analyses of long observational records ought to have lower-frequency internal Pekeris mode counterparts, a prediction that we confirm though analysis of 67 years of hourly global reanalysis data. Significance Statement Our demonstration that both a surface-trapped Lamb wave and a slower horizontal phase speed internal Pekeris wave can be realized as normal modes of the global atmosphere resolves a very long-standing and fundamental issue in dynamical meteorology. Our result also has broader implications. The 2022 Tonga eruption produced a surprisingly large ocean tsunami even in a remote ocean basin, and it is possible that the slower atmospheric Pekeris mode can play a role in exciting the remarkable ocean response. Also the spectral peaks seen in atmospheric variability corresponding to the Pekeris normal mode provide features for comparison with global model simulations of the atmosphere, along with the Lamb modes detected in earlier studies.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-21-7749-2021", "year": 2021, "title": "Effect of volcanic emissions on clouds during the 2008 and 2018 Kilauea degassing events", "abstract": "Abstract. Volcanic eruptions in otherwise clean environments are natural experiments wherein the effects of aerosol emissions on clouds and climate can be partitioned from meteorological variability and anthropogenic activities. In this work, we combined satellite retrievals, reanalysis products, and atmospheric modeling to analyze the mechanisms of aerosolcloud interactions during two degassing events at the Kilauea volcano in 2008 and 2018. The eruptive nature of the 2008 and 2018 degassing events was distinct from long-term volcanic activity for Kilauea. Although previous studies assessed the modulation of cloud properties from the 2008 event, this is the first time such an analysis has been reported for the 2018 event and that multiple degassing events have been analyzed and compared at this location. Both events resulted in significant changes in cloud effective radius and cloud droplet number concentration that were decoupled from local meteorology and in line with an enhanced cloud albedo. However, it is likely that the effects of volcanic emissions on liquid water path and cloud fraction were largely offset by meteorological variability. Comparison of cloud anomalies between the two events suggested a threshold response of aerosolcloud interactions to overcome meteorological effects, largely controlled by aerosol loading. In both events, the ingestion of aerosols within convective parcels enhanced the detrainment of condensate in the upper troposphere, resulting in deeper clouds than observed under pristine conditions. Accounting for ice nucleation on ash particles led to enhanced ice crystal concentrations at cirrus levels and a slight decrease in ice water content, improving the correlation of the model results with the satellite retrievals. Overall, aerosol loading, plume characteristics, and meteorology contributed to changes in cloud properties during the Kilauea degassing events.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-17-8599-2017", "year": 2017, "title": "Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements", "abstract": "Abstract. We apply a two-way transmittance constraint to nighttime CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations of volcanic aerosol layers to retrieve estimates of the particulate lidar ratio (Sp) at 532 nm. This technique is applied to three volcanic eruption case studies that were found to have injected aerosols directly into the stratosphere. Numerous lidar observations permitted characterization of the optical and geometric properties of the volcanic aerosol layers over a time period of 12 weeks. For the volcanic ash-rich layers produced by the Puyehue-Cordon Caulle eruption (June 2011), we obtain mean and median particulate lidar ratios of 69 13 sr and 67 sr, respectively. For the sulfate-rich aerosol layers produced by Kasatochi (August 2008) and Sarychev Peak (June 2009), the means of the retrieved lidar ratios were 66 19 sr (median 60 sr) and 63 14 sr (median 59 sr), respectively. The 532 nm layer-integrated particulate depolarization ratios (p) observed for the Puyehue layers (p = 0.33 0.03) were much larger than those found for the volcanic aerosol layers produced by the Kasatochi (p = 0.09 0.03) and Sarychev (p = 0.05 0.04) eruptions. However, for the Sarychev layers we observe an exponential decay (e-folding time of 3.6 days) in p with time from 0.27 to 0.03. Similar decreases in the layer-integrated attenuated colour ratios with time were observed for the Sarychev case. In general, the Puyehue layers exhibited larger colour ratios ( = 0.53 0.07) than what was observed for the Kasatochi ( = 0.35 0.07) and Sarychev ( = 0.32 0.07) layers, indicating that the Puyehue layers were generally composed of larger particles. These observations are particularly relevant to the new stratospheric aerosol subtyping classification scheme, which has been incorporated into version 4 of the level 2 CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data products.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3389/FEART.2019.00238", "year": 2019, "title": "Remotely sensed deformation and thermal anomalies at Mount Pagan, Mariana Islands", "abstract": "Volcanic islands in remote settings are challenging to study with ground-based instrumentation; nevertheless it is important to define normal background activity at these volcanoes because they pose threats to air and sea traffic. A combination of remote sensing methods is critical to adequately characterize volcanic activity, and in this study we present space-based observations of both thermal anomalies and surface deformation at Pagan Island in the Mariana Island Arc. Mt. Pagan produced a large eruption (>0.1 km3) in 1981, and recent smaller eruptions (>0.001 km3) in 2011 and 2012 that triggered volcanic ash advisories. In this study we examine available Interferometric Synthetic Aperture Radar (InSAR) from Envisat and ALOS between October 2004 and June 2010 for precursory deformation leading up to the most recent eruptions. Although we do not observe evidence for shallow magma reservoir inflation, we do observe a zone of subsidence of up to -3 cm/yr located on the northern flank likely caused by continuing scoria compaction of 1981 eruptive deposits. CosmoSkyMed InSAR measurements spanning the October 2012 eruption also shows deposit subsidence, but no detectable co-eruptive deflation. We also present remotely-sensed thermal time series from the MODIS and ASTER instruments spanning over a decade. There are two distinct locations of anomalous surface temperatures on the island, which correlate with previously documented, fumarolically active vents at South Pagan and Mt. Pagan. Ultimately, we did not find thermal or deformation precursors for recent eruptive activity, plausibly because the volcano had an open conduit and persistent degassing during this time period. We compare and contrast the efficacy of various sensor types currently available to characterize transient dynamics at small and remote volcanic islands such as Pagan.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1038/NCOMMS13192", "year": 2016, "title": "A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans", "abstract": "The Ethiopian Rift Valley hosts the longest record of human co-existence with volcanoes on Earth, however, current understanding of the magnitude and timing of large explosive eruptions in this region is poor. Detailed records of volcanism are essential for interpreting the palaeoenvironments occupied by our hominin ancestors; and also for evaluating the volcanic hazards posed to the 10 million people currently living within this active rift zone. Here we use new geochronological evidence to suggest that a 200 km-long segment of rift experienced a major pulse of explosive volcanic activity between 320 and 170 ka. During this period, at least four distinct volcanic centres underwent large-volume (>10 km3) caldera-forming eruptions, and eruptive fluxes were elevated five times above the average eruption rate for the past 700 ka. We propose that such pulses of episodic silicic volcanism would have drastically remodelled landscapes and ecosystems occupied by early hominin populations.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3389/FEART.2022.976962", "year": 2022, "title": "Out of the blue: Volcanic SO2 emissions during the 2021-2022 eruptions", "abstract": "Most volcanism on Earth is submarine, but volcanic gas emissions by submarine eruptions are rarely observed and hence largely unquantified. On 15 January 2022 a submarine eruption of Hunga Tonga-Hunga Haapai (HTHH) volcano (Tonga) generated an explosion of historic magnitude, and was preceded by 1 month of Surtseyan eruptive activity and two precursory explosive eruptions. We present an analysis of ultraviolet (UV) satellite measurements of volcanic sulfur dioxide (SO\r\n 2\r\n ) between December 2021 and the climactic 15 January 2022 eruption, comprising an unprecedented record of Surtseyan eruptive emissions. UV measurements from the Ozone Monitoring Instrument (OMI) on NASAs Aura satellite, the Ozone Mapping and Profiler Suite (OMPS) on Suomi-NPP, the Tropospheric Monitoring Instrument (TROPOMI) on ESAs Sentinel-5P, and the Earth Polychromatic Imaging Camera (EPIC) aboard the Deep Space Climate Observatory (DSCOVR) are combined to yield a consistent multi-sensor record of eruptive degassing. We estimate SO\r\n 2\r\n emissions during the eruptions key phases: the initial 19 December 2021 eruption (0.01 Tg SO\r\n 2\r\n ); continuous SO\r\n 2\r\n emissions from 20 December 2021early January 2022 (0.12 Tg SO\r\n 2\r\n ); the 13 January 2022 stratospheric eruption (0.06 Tg SO\r\n 2\r\n ); and the paroxysmal 15 January 2022 eruption (0.40.5 Tg SO\r\n 2\r\n ); yielding a total SO\r\n 2\r\n emission of 0.60.7 Tg SO\r\n 2\r\n for the eruptive episode. We interpret the vigorous SO\r\n 2\r\n emissions observed prior to the January 2022 eruptions, which were significantly higher than measured in the 2009 and 2014 HTHH eruptions, as strong evidence for a rejuvenated magmatic system. High cadence DSCOVR/EPIC SO\r\n 2\r\n imagery permits the first UV-based analysis of umbrella cloud spreading and volume flux in the 13 January 2022 eruption, and also tracks early dispersion of the stratospheric SO\r\n 2\r\n cloud injected on January 15. The 0.40.5 Tg SO\r\n 2\r\n discharged by the paroxysmal 15 January 2022 HTHH eruption is low relative to other eruptions of similar magnitude, and a review of other submarine eruptions in the satellite era indicates that modest SO\r\n 2\r\n yields may be characteristic of submarine volcanism, with the emissions and atmospheric impacts likely dominated by water vapor. The origin of the low SO\r\n 2\r\n loading awaits further investigation but scrubbing of SO\r\n 2\r\n in the water-rich eruption plumes and rapid conversion to sulfate aerosol are plausible, given the exceptional water emission by the 15 January 2022 HTHH eruption.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.DIB.2020.105113", "year": 2020, "title": "U\u2013Th whole rock data and high spatial resolution U\u2013Th disequilibrium and U\u2013Pb zircon ages of Mt. Erciyes and Mt. Hasan Quaternary stratovolcanic \u2026", "abstract": "Thirty-eight lava and pyroclastic samples were collected from Mt. Erciyes and Mt. Hasan, the two largest stratovolcanic complexes of the Central Anatolian Volcanic Province in Turkey. More than 1000 zircon crystals were dated by Secondary Ion Mass Spectrometry (SIMS) applying UTh disequilibrium and UPb methods. Model ages were calculated from zircon 230Th238U232Th isotopic compositions in combination with UTh whole rock data of digested lava samples generated by Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). Middle and Late Pleistocene ages dominate the dataset, but are complemented by both older (predominantly Early Pleistocene) and younger (Holocene) ages. UTh disequilibrium and UPb zircon data provide maximum eruption ages that can be further specified by (UTh)/He geochronology (zircon double dating). Additionally, these data are important to constrain the longevity and size of magmatic systems, and their potential for reactivation leading to potentially hazardous eruptions.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.GEOMORPH.2021.107842", "year": 2021, "title": "Digital Elevation Model resolution: Effects on the chronometry-oriented morphological analysis of monogenetic scoria cones in the Sierra Chichinautzin, central \u2026", "abstract": "Morphological characterization of monogenetic cones provides essential information on different genetic, evolutionary, and hazard-related features of dispersive volcanism. Specifically, it may be used to measure the degree of erosional shape alteration of scoria cones, and from there, to estimate the age of individual volcanoes in extensive volcanic fields and the hazard implications of the cones' age distribution. Here we compare diverse morphometric parameters, some resulting from the elevation profiles analyses, and a novel one obtained from a shape characterization of elevation contours using Elliptical Fourier Descriptors, of 19 radiometrically-dated monogenetic scoria cones in the Sierra Chichinautzin Volcanic Field in Central Mexico. The parameters were calculated from two independent Digital Elevation Models with different resolutions: the 12 m resolution TanDEM-X SAR database, and a 5 m resolution airborne LIDAR DEM. From the analysis of the available information on the volcanic cones in the age range 1.6 to 222 ka, we conclude that the age-relevant morphometric parameters calculated from the TanDEM-X satellite DEM render alike values and perform equally well as the LIDAR airborne DEM for the morpho-chronological characterization of scoria cones, expanding the role of digital satellite elevation data to the study of detailed features of distributed volcanism at a global level.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ESSD-10-469-2018", "year": 2018, "title": "A global space-based stratospheric aerosol climatology: 1979\u20132016", "abstract": "Abstract. We describe the construction of a continuous 38-year record of stratospheric aerosol optical properties. The Global Space-based Stratospheric Aerosol Climatology, or GloSSAC, provided the input data to the construction of the Climate Model Intercomparison Project stratospheric aerosol forcing data set (19792014) and we have extended it through 2016 following an identical process. GloSSAC focuses on the Stratospheric Aerosol and Gas Experiment (SAGE) series of instruments through mid-2005, and on the Optical Spectrograph and InfraRed Imager System (OSIRIS) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data thereafter. We also use data from other space instruments and from ground-based, air, and balloon borne instruments to fill in key gaps in the data set. The end result is a global and gap-free data set focused on aerosol extinction coefficient at 525 and 1020 nm and other parameters on an as available basis. For the primary data sets, we developed a new method for filling the post-Pinatubo eruption data gap for 19911993 based on data from the Cryogenic Limb Array Etalon Spectrometer. In addition, we developed a new method for populating wintertime high latitudes during the SAGE period employing a latitude-equivalent latitude conversion process that greatly improves the depiction of aerosol at high latitudes compared to earlier similar efforts. We report data in the troposphere only when and where it is available. This is primarily during the SAGE II period except for the most enhanced part of the Pinatubo period. It is likely that the upper troposphere during Pinatubo was greatly enhanced over non-volcanic periods and that domain remains substantially under-characterized. We note that aerosol levels during the OSIRIS/CALIPSO period in the lower stratosphere at mid- and high latitudes is routinely higher than what we observed during the SAGE II period. While this period had nearly continuous low-level volcanic activity, it is possible that the enhancement in part reflects deficiencies in the data set. We also expended substantial effort to quality assess the data set and the product is by far the best we have produced. GloSSAC version 1.0 is available in netCDF format at the NASA Atmospheric Data Center at https://eosweb.larc.nasa.gov/. GloSSAC users should cite this paper and the data set DOI (https://doi.org/10.5067/GloSSAC-L3-V1.0).", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/GMD-14-5751-2021", "year": 2021, "title": "Incorporation of volcanic SO2 emissions in the Hemispheric CMAQ (H-CMAQ) version 5.2 modeling system and assessing their impacts on sulfate aerosol \u2026", "abstract": "Abstract. The state-of-the-science Community Multiscale Air Quality (CMAQ) Modeling System has recently been extended for hemispheric-scale modeling applications (referred to as H-CMAQ). In this study, satellite-constrained estimation of the degassing SO2 emissions from 50 volcanoes over the Northern Hemisphere is incorporated into H-CMAQ, and their impact on tropospheric sulfate aerosol (SO42-) levels is assessed for 2010. The volcanic degassing improves predictions of observations from the Acid Deposition Monitoring Network in East Asia (EANET), the United States Clean Air Status and Trends Network (CASTNET), and the United States Integrated Monitoring of Protected Visual Environments (IMPROVE). Over Asia, the increased SO42- concentrations were seen to correspond to the locations of volcanoes, especially over Japan and Indonesia. Over the USA, the largest impacts that occurred over the central Pacific were caused by including the Hawaiian Kilauea volcano, while the impacts on the continental USA were limited to the western portion during summertime. The emissions of the Soufriere Hills volcano located on the island of Montserrat in the Caribbean Sea affected the southeastern USA during the winter season. The analysis at specific sites in Hawaii and Florida also confirmed improvements in regional performance for modeled SO42- by including volcanoes SO2 emissions. At the edge of the western USA, monthly averaged SO42- enhancements greater than 0.1 g m3 were noted within the boundary layer (defined as surface to 750 hPa) during JuneSeptember. Investigating the change on SO42- concentration throughout the free troposphere revealed that although the considered volcanic SO2 emissions occurred at or below the middle of free troposphere (500 hPa), compared to the simulation without the volcanic source, SO42- enhancements of more than 10 % were detected up to the top of the free troposphere (250 hPa). Our model simulations and comparisons with measurements across the Northern Hemisphere indicate that the degassing volcanic SO2 emissions are an important source and should be considered in air quality model simulations assessing background SO42- levels and their source attribution.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1038/NATURE22974", "year": 2017, "title": "Strong constraints on aerosolcloud interactions from volcanic eruptions", "abstract": "Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosolcloud interactions. Here we show that the massive 20142015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud dropletsconsistent with expectationsbut had no discernible effect on other cloud properties. The reduction in droplet size led to cloud brightening and global-mean radiative forcing of around 0.2 watts per square metre for September to October 2014. Changes in cloud amount or cloud liquid water path, however, were undetectable, indicating that these indirect effects, and cloud systems in general, are well buffered against aerosol changes. This result will reduce uncertainties in future climate projections, because we are now able to reject results from climate models with an excessive liquid-water-path response.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/NHESS-22-2829-2022", "year": 2022, "title": "Insights into the vulnerability of vegetation to tephra fallouts from interpretable machine learning and big Earth observation data", "abstract": "Abstract. Although the generally high fertility of volcanic soils is often seen as an opportunity, short-term consequences of eruptions on natural and cultivated vegetation are likely to be negative. The empirical knowledge obtained from post-event impact assessments provides crucial insights into the range of parameters controlling impact and recovery of vegetation, but their limited coverage in time and space offers a limited sample of all possible eruptive and environmental conditions. Consequently, vegetation vulnerability remains largely unconstrained, thus impeding quantitative risk analyses. Here, we explore how cloud-based big Earth observation data, remote sensing and interpretable machine learning (ML) can provide a large-scale alternative to identify the nature of, and infer relationships between, drivers controlling vegetation impact and recovery. We present a methodology developed using Google Earth Engine to systematically revisit the impact of past eruptions and constrain critical hazard and vulnerability parameters. Its application to the impact associated with the tephra fallout from the 2011 eruption of Cordon Caulle volcano (Chile) reveals its ability to capture different impact states as a function of hazard and environmental parameters and highlights feedbacks and thresholds controlling impact and recovery of both natural and cultivated vegetation. We therefore conclude that big Earth observation (EO) data and machine learning complement existing impact datasets and open the way to a new type of dynamic and large-scale vulnerability models.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JVOLGEORES.2022.107713", "year": 2023, "title": "Structural analysis of fracture networks controlling geothermal activity in the northern part of the Malawi Rifted Zone from aeromagnetic and remote sensing data", "abstract": "We investigated the relationship between the geothermal activity and fracture networks that control storage and fluid pathways of geothermal systems in the northern part of the Malawi Rifted Zone (MRZ). It is suggested that low to medium temperature geothermal systems in the MRZ are mainly non-magmatic and structurally controlled. However, structural controls and favorable settings of geothermal activity are poorly understood in this region. We used an approach of remote sensing and aeromagnetic data analysis to 1) identify and characterize fracture networks to better understand the structural controls of geothermal activity in the northern part of the rift, 2) quantify and identify permeable areas using topological analysis of fracture intensity and connectivity frequency proxies, 3) understand the role that inherited structures play in the geothermal systems of the northern part of the rift, and 4) build preliminary geothermal conceptual models of selected geothermal systems. Our findings show that fracture networks in the Karonga and Nkhata regions comprise a varying degree of complexity along strike. This structural complexity occurs mainly in favorable structural settings such as 1) two fault segments coalescing to form hard and soft-linked relays, 2) two different oriented fracture segments intersecting each other, and 3) on the tips of major normal faults. The hot springs are located where one or more of these favorable settings occur. The remote sensing analysis shows that Quaternary normal faults are the primary controlling structures of thermal waters at shallow depths in the Karonga (NW-SE to N-S strike) and Nkhata (N-S strike) regions. The aeromagnetic data revealed that permeable NW-striking foliation planes of the Precambrian Mugesse Shear Zone and WNW to ENE-striking foliation planes of the Mwembeshi Shear Zone are important structural controls of geothermal fluids at greater depths in the Karonga and Nkhata region, respectively. The Mwankeja-Mwesia and Chiweta geothermal systems in the Karonga region show favorable structural settings for geothermal fluids related to NNW and NW-striking normal faults segments that coalesce to form hard and soft-linked relay ramps and NW, and NNE -striking faults intersecting each other and NW-striking foliation planes. The Mtondolo geothermal area in the Nkhata region shows that the intersection of N-striking normal faults and ENE-striking foliation planes is the favorable structural setting that controls the emergence of hot springs through the surface. We conclude that high fracture intensity and connectivity are related to the location of the hot springs at the surface and can be used to determine permeable zones and hidden geothermal fluids together with other methodologies. The aeromagnetic data analysis suggested that buried faults and inherited structures (e.g., foliation planes) are controlling the geothermal fluids at depth. Additionally, our aeromagnetic analysis of magnetic basement depth estimation suggests that some of the geothermal reservoirs in the northern part of the MRZ could have an estimated depth of ~ 500 to 1000 m.b.g.l. Finally, the low-cost methodology applied in this study can reduce the risk of drilling non-productive wells in the early exploration stages and become an exploration strategy for similar geothermal systems in countries of the Western Branch of the East African Rift System.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3389/FEART.2020.577588", "year": 2021, "title": "Time-scales of inter-eruptive volcano uplift signals: Three Sisters volcanic center, Oregon (United States)", "abstract": "A classical inflation-eruption-deflation cycle of a volcano is useful to conceptualize the time-evolving deformation of volcanic systems. Such a model predicts accelerated uplift during pre-eruptive periods, followed by subsidence during the co-eruptive stage. Some volcanoes show puzzling persistent uplift signals with minor or no other geophysical or geochemical variations, which are difficult to interpret. Such temporal behaviors are usually observed in large calderas (e.g., Yellowstone, Long Valley, Campi Flegrei, Rabaul), but less commonly for stratovolcanoes. Volcano deformation needs to be better understood during inter-eruptive stages, to assess its value as a tool for forecasting eruptions and to understand the processes governing the unrest behavior. Here, we analyze inter-eruptive uplift signals at Three Sisters, a complex stratovolcano in Oregon (United States), which in recent decades shows persistent inter-eruptive uplift signals without associated eruptive activity. Using a Bayesian inversion method, we re-assessed the source characteristics (magmatic system geometry and location) and its uncertainties. Furthermore, we evaluate the most recent evolution of the surface deformation signals combining both GPS and InSAR data through a new non-subjective linear regularization inversion procedure to estimate the 26 years-long time-series. Our results constrain the onset of the Three Sisters volcano inflation to be between October 1998 and August 1999. In the absence of new magmatic inputs, we estimate a continuous uplift signal, at diminishing but detectable rates, to last for few decades. The observed uplift decay observed at Three Sisters is consistent with a viscoelastic response of the crust, with viscosity of 1018 Pa s around a magmatic source with a pressure change which increases in finite time to a constant value. Finally, we compare Three Sisters volcano time series with historical uplift at different volcanic systems. Proper modeling of scaled inflation time series indicates a unique and well-defined exponential decay in temporal behavior. Such evidence supports that this common temporal evolution of uplift rates could be a potential indicator of a rather reduced set of physical processes behind inter-eruptive uplift signals.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021JD035472", "year": 2021, "title": "Modeling the Sulfate Aerosol Evolution After Recent Moderate Volcanic Activity, 20082012", "abstract": "Volcanic activity is a major natural climate forcing and an accurate representation of volcanic aerosols in global climate models is essential. This is a complex task involving many uncertainties in the model design and setup and observations. We analyze the performance of the aerosol-chemistry-climate model SOCOL-AERv2 for three medium-sized volcanic eruptions. We focus on the impact of differences in volcanic plume height and SO2 estimates on the stratospheric aerosol burden. The influence of internal model variability and dynamics are addressed through an ensemble of free-running and nudged simulations at different vertical resolutions. Comparing the modeled evolution of the stratospheric aerosol loading to satellite measurements reveals a good model performance. However, a conclusive validation is complicated by uncertainties in observations and emission estimates. The large spread in emitted sulfur amount and its vertical distribution consequently lead to differences in simulated aerosol burdens. Varying tropopause heights among free-running simulations add to these differences, modulating the amount of sulfur injected into the stratosphere. In nudged mode, volcanic aerosol burden peaks are well reproduced, however changes in convection and clouds affect SO2 oxidation paths and cross-tropopause transport, leading to increased background burdens compared to observations. This effect can be reduced by leaving temperatures unconstrained. A higher vertical resolution of 90 levels increases the stratospheric residence time of sulfate aerosol by reducing the diffusion out of the tropical reservoir. We conclude that the model set-up (vertical resolution and free-running vs. nudged) as well as forcing parameters (volcanic emission strength and plume height) contribute equally to the model uncertainties.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-21-1143-2021", "year": 2021, "title": "Evidence for the predictability of changes in the stratospheric aerosol size following volcanic eruptions of diverse magnitudes using space-based instruments", "abstract": "Abstract. An analysis of multiwavelength stratospheric aerosol extinction coefficient data from the Stratospheric Aerosol and Gas Experiment II and III/ISS instruments is used to demonstrate a coherent relationship between the perturbation in extinction coefficient in an eruption's main aerosol layer and the wavelength dependence of that perturbation. This relationship spans multiple orders of magnitude in the aerosol extinction coefficient of stratospheric impact of volcanic events. The relationship is measurement-based and does not rely on assumptions about the aerosol size distribution. We note limitations on this analysis including that the presence of significant amounts of ash in the main sulfuric acid aerosol layer and other factors may significantly modulate these results. Despite these limitations, the findings suggest an avenue for improving aerosol extinction coefficient measurements from single-channel observations such as the Optical Spectrograph and Infrared Imager System as they rely on a prior assumptions about particle size. They may also represent a distinct avenue for the comparison of observations with interactive aerosol models used in global climate models and Earth system models.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1117/12.2241382", "year": 2016, "title": "Analyzing land surface temperature variations during Fogo Island (Cape Verde) 2014-2015 eruption with Landsat 8 images", "abstract": "Land Surface Temperature (LST) is an important parameter related to land surface processes that changes continuously through time. Assessing its dynamics during a volcanic eruption has both environmental and socio-economical interest. Lava flows and other volcanic materials produced and deposited throughout an eruption transform the landscape, contributing to its heterogeneity and altering LST measurements. This paper aims to assess variations of satellite-derived LST and to detect patterns during the latest Fogo Island (Cape Verde) eruption, extending from November 2014 through February 2015. LST data was obtained through four processed Landsat 8 images, focused on the caldera where Pico do Fogo volcano sits. QGIS plugin Semi-Automatic Classification was used in order to apply atmospheric corrections and radiometric calibrations. The algorithm used to retrieve LST values is a single-channel method, in which emissivity values are known. The absence of in situ measurements is compensated by the use of MODIS sensor-derived LST data, used to compare with Landsat retrieved measurements. LST data analysis shows as expected that the highest LST values are located inside the caldera. High temperature values were also founded on the south-facing flank of the caldera. Although spatial patterns observed on the retrieved data remained roughly the same during the time period considered, temperature values changed throughout the area and over time, as it was also expected. LST values followed the eruption dynamic experiencing a growth followed by a decline. Moreover, it seems possible to recognize areas affected by lava flows of previous eruptions, due to well-defined LST spatial patterns.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/AMT-14-7545-2021", "year": 2021, "title": "Tracking aerosols and SO2 clouds from the Raikoke eruption: 3D view from satellite observations", "abstract": "Abstract. The 21 June 2019 eruption of the Raikoke volcano (Kuril Islands, Russia; 48 N, 153 E) produced significant amounts of volcanic aerosols (sulfate and ash) and sulfur dioxide (SO2) gas that penetrated into the lower stratosphere. The dispersed SO2 and sulfate aerosols in the stratosphere were still detectable by multiple satellite sensors for many months after the eruption. For this study of SO2 and aerosol clouds we use data obtained from two of the Ozone Mapping and Profiler Suite sensors on the Suomi National Polar-orbiting Partnership satellite: total column SO2 from the Nadir Mapper and aerosol extinction profiles from the Limb Profiler as well as other satellite data sets. We evaluated the limb viewing geometry effect (the arch effect) in the retrieval of the LP standard aerosol extinction product at 674 nm. It was shown that the amount of SO2 decreases with a characteristic period of 818 d and the peak of stratospheric aerosol optical depth recorded at a wavelength of 674 nm lags the initial peak of SO2 mass by 1.5 months. Using satellite observations and a trajectory model, we examined the dynamics of an unusual atmospheric feature that was observed, a stratospheric coherent circular cloud of SO2 and aerosol from 18 July to 22 September 2019.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1130/B31931.1", "year": 2019, "title": "The origin and evolution of breakouts in a cooling-limited rhyolite lava flow", "abstract": "Understanding lava flow processes is important for interpreting existing lavas and for hazard assessments. Although substantial progress has been made for basaltic lavas our understanding of silicic lava flows has seen limited recent advance. In particular, the formation of lava flow breakouts, which represent a characteristic process in cooling-limited basaltic lavas, but has not been described in established models of rhyolite emplacement. Using data from the 20112012 rhyolite eruption of Puyehue-Cordon Caulle, Chile, we develop the first conceptual framework to classify breakout types in silicic lavas, and to describe the processes involved in their progressive growth, inflation, and morphological change. By integrating multi-scale satellite, field, and textural data from Cordon Caulle, we interpret breakout formation to be driven by a combination of pressure increase (from local vesiculation in the lava flow core, as well as from continued supply via extended thermally preferential pathways) and a weakening of the surface crust through lateral spreading and fracturing. Small breakouts, potentially resulting more from local vesiculation than from continued magma supply, show a domed morphology, developing into petaloid as inflation increasingly fractures the surface crust. Continued growth and fracturing results in a rubbly morphology, with the most inflated breakouts developing into a cleft-split morphology, reminiscent of tumulus inflation structures seen in basalts. These distinct morphological classes result from the evolving relative contributions of continued breakout advance and inflation. The extended nature of some breakouts highlights the role of lava supply under a stationary crust, a process ubiquitous in inflating basalt lava flows that reflects the presence of thermally preferential pathways. Textural analyses of the Cordon Caulle breakouts also emphasize the importance of late-stage volatile exsolution and vesiculation within the lava flow. Although breakouts occur across the compositional spectrum of lava flows, the greater magma viscosity is likely to make late-stage vesiculation much more important for breakout development in silicic lavas than in basalts. Such late-stage vesiculation has direct implications for hazards previously recognized from silicic lava flows, enhancing the likelihood of flow front collapse, and explosive decompression of the lava core.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/ATMOS11050548", "year": 2020, "title": "Investigating the Large-Scale Transport of a Volcanic Plume and the", "abstract": "Volcanic plumes can be transported across vast distances and can have an impact on solar ultraviolet radiation (UVR) reaching the surface due to the scattering and absorption caused by aerosols. The dispersion of the volcanic plume from the Puyehue-Cordon Caulle volcanic complex (PCCVC) eruption was investigated to determine the effect on aerosol loading at Cape Point, South Africa. The eruption occurred on 4 June 2011 and resulted in a plume reaching a height of between 9 and 12 km and was dispersed across the Southern Hemisphere. Satellite sulphur dioxide (SO2) observations and a dispersion model showed low concentrations of SO2 at the secondary site. However, satellite observations of volcanic ash and ground-based aerosol measurements did show increases between 10 and 20 June 2011 at the secondary site. Furthermore, there was good agreement with the dispersion model results and observations from satellites with most of the plume located between latitudes 4060 South.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.OREGEOREV.2020.103491", "year": 2020, "title": "The submarine tectono-magmatic framework of Cu-Au endowment in the Tabar-to-Feni island chain, PNG", "abstract": "The Southwest Pacific region, and Papua New Guinea in particular, is spectacularly endowed with mineral resources, including some of the youngest and richest porphyry Cu-Mo-Au deposits in the world. Among them is the giant porphyry-epithermal Ladolam Au deposit on Lihir Island in the Tabar-Lihir-Tanga-Feni (TLTF) island chain, northeast of New Ireland. Its setting within a former forearc basin is very different from most Southwest Pacific porphyry and epithermal deposits. Our synthesis of published and previously unreleased data from ship-based multibeam and seismic studies, satellite gravimetry, geochemistry and geochronology reveals a far more complex crustal structure and composition than is presently understood from the geology of the islands alone. We show that the unique regional Au endowment results from the alignment of various preconditions that are prolific to ore formation: i) hydrous and metal-rich metasomatic veins in the mantle source, ii) second-stage, low volume partial melting due to incipient rifting, iii) high volatile contents and oxygen fugacities of the melts due to preferential melting of hydrous phases in the metasomatic veins, and iv) in the specific case of Lihir, unroofing of the volcanic edifice that led to boiling and rapid metal deposition. This study shows that the location of the Ladolam deposit on Lihir is controlled by large-scale structures that can be traced offshore and are the site of continuing submarine volcanism and epithermal-style Au mineralization. The observed structural framework is dominated by the emergence of trans-lithospheric faults that provided pathways for the melts to the seafloor, near-surface structural focusing of the ascending melts and fluids, and a regional tectonic stress regime that stabilized the conditions over a significant period of time and/or repeatedly. Marine seismic data confirms the complex structure of the TLTF island chain. Each island group sits on tilted blocks that form horst structures separated by half grabens developed due to regional NW-SE-directed extension. Regional compression perpendicular to the extension continues as a result of the transition from subduction to collision at the leading edge of the Ontong Java Plateau. The protracted, transtensional motion between distinct crustal blocks controls the location and timing of magmatism and mineralization. A kinematic link between volcanism at the location of Lihir and the splitting of New Ireland by NE-directed propagation of seafloor spreading in the Manus Basin is suspected. By combining onshore and offshore geology, we propose a new model of the evolution of the New Ireland Basin, magmatism along the TLTF island chain and ultimately ore deposit formation. This study demonstrates the importance of integrating offshore geology and geophysics into models that aim to explain the structural, magmatic, and sedimentary evolution of marginal basins that are host to economic mineral deposits.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S10040-022-02545-X", "year": 2022, "title": "Effects of structure and volcanic stratigraphy on groundwater and surface water flow: Hat Creek basin, California, USA", "abstract": "Hydrogeologic systems in the southern Cascade Range in California (USA) develop in volcanic rocks where morphology, stratigraphy, extensional structures, and attendant basin geometry play a central role in groundwater flow paths, groundwater/surface-water interactions, and spring discharge locations. High-volume springs (greater than 3 m3/s) flow from basin-filling (<800 ka) volcanic rocks in the Hat Creek and Fall River tributaries and contribute approximately half of the average annual flow of the Pit River, the largest tributary to Shasta Lake. A hydrogeologic conceptual framework is constructed for the Hat Creek basin combining new geologic mapping, water-well lithologic logs, a database of active faults, LiDAR mapping of faults and volcanic landforms, streamflow measurements and airborne thermal infrared remote sensing of stream temperature. These data are used to integrate the geologic structure and the volcanic and volcaniclastic stratigraphy to create a three-dimensional interpretation of the hydrogeology in the basin. Two large streamflow gains from focused groundwater discharge near Big Spring and north of Sugarloaf Peak result from geologic barriers that restrict lateral groundwater flow and force water into Hat Creek. The inferred groundwater-flow barriers divide the aquifer system into at least three leaky compartments. The two downstream compartments lose streamflow in the upstream reaches (immediately downstream of the groundwater-flow barriers) and gain in downstream reaches with the greatest inflows immediately upstream of the barriers.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/AMT-14-7153-2021", "year": 2021, "title": "Methodology to obtain highly resolved SO2 vertical profiles for representation of volcanic emissions in climate models", "abstract": "Abstract. In this study we describe a methodology to create high-vertical-resolution SO2 profiles from volcanic emissions. We demonstrate the method's performance for the volcanic clouds following the eruption of Sarychev in June 2009. The resulting profiles are based on a combination of satellite SO2 and aerosol retrievals together with trajectory modelling. We use satellite-based measurements, namely lidar backscattering profiles from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) satellite instrument, to create vertical profiles for SO2 swaths from the Atmospheric Infrared Sounder (AIRS) aboard the Aqua satellite. Vertical profiles are created by transporting the air containing volcanic aerosol seen in CALIOP observations using the FLEXible PARTicle dispersion model (FLEXPART) while preserving the high vertical resolution using the potential temperatures from the MERRA-2 (Modern-Era Retrospective analysis for Research and Application) meteorological data for the original CALIOP swaths. For the Sarychev eruption, air tracers from 75 CALIOP swaths within 9 d after the eruption are transported forwards and backwards and then combined at a point in time when AIRS swaths cover the complete volcanic SO2 cloud. Our method creates vertical distributions for column density observations of SO2 for individual AIRS swaths, using height information from multiple CALIOP swaths. The resulting dataset gives insight into the height distribution in the different sub-clouds of SO2 within the stratosphere. We have compiled a gridded high-vertical-resolution SO2 inventory that can be used in Earth system models, with a vertical resolution of 1 K in potential temperature, 61 56 m, or 1.8 2.9 mbar.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JVOLGEORES.2020.107171", "year": 2021, "title": "Zircon double-dating of Quaternary eruptions on Jeju Island, South Korea", "abstract": "Models of volcanic eruption periodicity are vital for hazard prediction, but require an understanding of the past pattern of melt evolution and transport. Zircon double-dating combines (U-Th)/He methods with U-Pb or U-Th disequilibrium geochronology to determine the timing of volcanic eruptions for rocks with a particular emphasis on those younger than ca. 1 Ma. This paper focuses on the Jeju Island intraplate volcano in South Korea, and compares a previously proposed model for trachyte eruption with new zircon double-dating results.

The results document four episodes of trachyte eruption on Jeju. The oldest trachytes were erupted at ca. 750-477 ka, followed by an episode at ca. 97-53 ka. Two further eruptive episodes occurred at ca. 31-23 ka and ca. 2 ka. This ca. 2 ka eruption age is the first geochronological documentation of such young eruptive activity from the island. In addition to the new eruption ages, there is evidence for three separate stages of zircon crystallisation, which are correlated with the three oldest eruption stages. The strong temporal correlation of zircon crystallisation and eruption on Jeju points to a simple magmatic plumbing system. These observations have important implications for hazard monitoring and mitigation on Jeju Island by highlighting the historical trachyte eruptions and the magmatic tempo for this system.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1002/2015JD023134", "year": 2016, "title": "Satellite-based global volcanic SO2emissions and sulfate direct radiative forcing during 2005-2012", "abstract": "An 8 year volcanic SO2 emission inventory for 2005-2012 is obtained based on satellite measurements of SO2 from OMI (Ozone Monitoring Instrument) and ancillary information from the Global Volcanism Program. It includes contributions from global volcanic eruptions and from eight persistently degassing volcanoes in the tropics. It shows significant differences in the estimate of SO2 amount and injection height for medium to large volcanic eruptions as compared to the counterparts in the existing volcanic SO2 database. Emissions from Nyamuragira (DR Congo) in November 2006 and Gr\u00edmsv\u00f6tn (Iceland) in May 2011 that were not included in the Intergovernmental Panel on Climate Change 5 (IPCC) inventory are included here. Using the updated emissions, the volcanic sulfate (SO42-) distribution is simulated with the global transport model Goddard Earth Observing System (GEOS)-Chem. The simulated time series of sulfate aerosol optical depth (AOD) above 10 km captures every eruptive volcanic sulfate perturbation with a similar magnitude to that measured by Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). The 8 year average contribution of eruptive SO42- to total SO42- loading above 10 km is ~10% over most areas of the Northern Hemisphere, with a maxima of 30% in the tropics where the anthropogenic emissions are relatively smaller. The persistently degassing volcanic SO42- in the tropics barely reaches above 10 km, but in the lower atmosphere it is regionally dominant (60%+ in terms of mass) over Hawaii and other oceanic areas northeast of Australia. Although the 7 year average (2005-2011) of eruptive volcanic sulfate forcing of -0.10 W m-2 in this study is comparable to that in the 2013 IPCC report (-0.09 W m-2), significant discrepancies exist for each year. Our simulations also imply that the radiative forcing per unit AOD for volcanic eruptions can vary from -40 to -80 W m-2, much higher than the -25 W m-2 implied in the IPCC calculations. In terms of sulfate forcing efficiency with respect to SO2 emission, eruptive volcanic sulfate is 5 times larger than anthropogenic sulfate. The sulfate forcing efficiency from degassing volcanic sources is close to that of anthropogenic sources. This study highlights the importance of characterizing both volcanic emission amount and injection altitude as well as the key role of satellite observations in maintaining accurate volcanic emissions inventories.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2022SW003101", "year": 2022, "title": "Significant Ionospheric Hole and Equatorial Plasma Bubbles After the 2022 Tonga Volcano Eruption", "abstract": "This paper investigates the local and global ionospheric responses to the 2022 Tonga volcano eruption, using ground-based Global Navigation Satellite System total electron content (TEC), Swarm in situ plasma density measurements, the Ionospheric Connection Explorer (ICON) Ion Velocity Meter (IVM) data, and ionosonde measurements. The main results are as follows: (a) A significant local ionospheric hole of more than 10 TECU depletion was observed near the epicenter \u223c45 min after the eruption, comprising of several cascading TEC decreases and quasi-periodic oscillations. Such a deep local plasma hole was also observed by space-borne in situ measurements, with an estimated horizontal radius of 10-15\u00b0 and persisted for more than 10 hr in ICON-IVM ion density profiles until local sunrise. (b) Pronounced post-volcanic evening equatorial plasma bubbles (EPBs) were continuously observed across the wide Asia-Oceania area after the arrival of volcano-induced waves; these caused a Ne decrease of 2-3 orders of magnitude at Swarm/ICON altitude between 450 and 575 km, covered wide longitudinal ranges of more than 140\u00b0, and lasted around 12 hr. (c) Various acoustic-gravity wave modes due to volcano eruption were observed by accurate Beidou geostationary orbit (GEO) TEC, and the huge ionospheric hole was mainly caused by intense shock-acoustic impulses. TEC rate of change index revealed globally propagating ionospheric disturbances at a prevailing Lamb-wave mode of \u223c315 m/s; the large-scale EPBs could be seeded by acoustic-gravity resonance and coupling to less-damped Lamb waves, under a favorable condition of volcano-induced enhancement of dusktime plasma upward E\u00d7B drift and postsunset rise of the equatorial ionospheric F-layer.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-22-6787-2022", "year": 2022, "title": "Improved estimation of volcanic SO2 injections from satellite retrievals and Lagrangian transport simulations: the 2019 Raikoke eruption", "abstract": "Abstract. Monitoring and modeling of volcanic plumes are important for understanding the impact of volcanic activity on climate and for practical concerns, such as aviation safety or public health. Here, we apply the Lagrangian transport model Massive-Parallel Trajectory Calculations (MPTRAC) to estimate the SO2 injections into the upper troposphere and lower stratosphere by the eruption of the Raikoke volcano (48.29 N, 153.25 E) in June 2019 and its subsequent long-range transport and dispersion. First, we used SO2 retrievals from the AIRS (Atmospheric Infrared Sounder) and TROPOMI (TROPOspheric Monitoring Instrument) satellite instruments together with a backward trajectory approach to estimate the altitude-resolved SO2 injection time series. Second, we applied a scaling factor to the initial estimate of the SO2 mass and added an exponential decay to simulate the time evolution of the total SO2 mass. By comparing the estimated SO2 mass and the mass from TROPOMI retrievals, we show that the volcano injected 2.1 0.2 Tg SO2, and the e-folding lifetime of the SO2 was about 13 to 17 d. The reconstructed SO2 injection time series are consistent between using the AIRS nighttime and the TROPOMI daytime products. Further, we compared forward transport simulations that were initialized by AIRS and TROPOMI SO2 products with a constant SO2 injection rate. The results show that the modeled SO2 change, driven by chemical reactions, captures the SO2 mass variations from TROPOMI retrievals. In addition, the forward simulations reproduce the SO2 distributions in the first 10 d after the eruption. However, diffusion in the forward simulations is too strong to capture the internal structure of the SO2 clouds, which is further quantified in the simulation of the compact SO2 cloud from late July to early August. Our study demonstrates the potential of using combined nadir satellite retrievals and Lagrangian transport simulations to further improve SO2 time- and height-resolved injection estimates of volcanic eruptions.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1093/PETROLOGY/EGAB086", "year": 2021, "title": "Fluid Fluxing and Accumulation Drive Decadal and Short-Lived Explosive", "abstract": "Abstract\r\n Some volcanoes are known for repeatedly producing explosive but short-lived eruptions (< half a day) every decade or so. These eruptions are often preceded by limited unrest signals and short run-up times to eruption (a few hours to months), and thus they are difficult to anticipate. Some well-documented examples are the 1990 and 2014 eruptions of Kelud volcano in Indonesia, or the 2015 Calbuco eruption in Chile. Here we interrogate the rock record and obtain insights into the processes and pre-eruptive conditions that led to the 1990 Kelud eruption, which we integrate with monitoring data (seismicity, lake temperature and hydro-acoustics, sulfur emissions) towards a conceptual model for this type of events. Mineral-melt geothermobarometers indicate that the basaltic andesite magma carried a crystal cargo from as deep as 1519 km, and reached volatile saturation at 49 km with 24 wt.% water in the melt. The textures and compositional zoning of orthopyroxene and plagioclase do not support intrusion of more primitive magma as the driver for the eruption, and we instead propose that pre-eruptive fluid accumulation and high-temperature fluid fluxing from depth (likely dominated by CO2) played a major role in priming the eruption to occur. Such pre-eruptive gas accumulation is also supported by mass balance calculation of the emitted excess SO2 gas. Mg-Fe diffusion profiles in reversely zoned pyroxenes constrain timescales of weeks to months before eruption for fluid addition to the reservoir, and such events may be recorded in the monitoring signals, especially in the change of hydroacoustics and water lake temperature, and probably in the seismic swarms. We propose that fluid exsolution and accumulation in the shallow reservoir plays a crucial role in modulating and triggering short-lived explosive eruptions with brief unrest at Kelud and probably other volcanoes worldwide.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2022GL099293", "year": 2022, "title": "Satellite Detection of a Massive Phytoplankton Bloom Following the 2022 Submarine Eruption of the Hunga Tonga\u2010Hunga Ha\u02bbapai Volcano", "abstract": "The largest submarine volcanic eruption of this century led to a dramatic phytoplankton bloom north of the island of Tongatapu, in the Kingdom of Tonga. In the absence of shipboard observations, we reconstructed the dynamics of this event by using a suite of satellite observations. Two independent bio-optical approaches confirmed that the phytoplankton bloom was a robust observation and not an optical artifact due to volcanogenic material. Furthermore, the timing, size, and position of the phytoplankton bloom suggest that plankton growth was primarily stimulated by nutrients released from volcanic ash rather than by nutrients upwelled through submarine volcanic activity. The appearance of a large region with high chlorophyll a concentrations <48 hr after the largest eruptive phase indicates a fast ecosystem response to nutrient fertilization. However, net phytoplankton growth probably initiated before the main eruption, when weaker volcanism had already fertilized the ocean.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1002/PPP.1989", "year": 2019, "title": "Shallow ground temperature measurements on the highest volcano on Earth", "abstract": "Mt. Ojos del Salado (6893 m a.s.l.) lies within the Andean Arid Diagonal, on the Chilean\u2013Argentinean border. Due to the extremely arid climate, surface ice is not widespread on Mt. Ojos del Salado and at similar high\u2011altitude massifs in the region, although ice\u2011bearing permafrost might be present. However, the thermal regime of the ground is relatively unknown in the region, especially outside of rock glaciers at high elevations north of 30\u00b0S. To study ground thermal regimes, in\u2011situ shallow ground temperature and snow coverage from satellite imagery have been surveyed for four years (2012\u20132016) at six sites between the elevations of 4200\u20136893 m a.s.l. on Mt. Ojos del Salado (27\u00b007\u2032S, 68\u00b032\u2032W). According to the ground temperature and snow coverage data at the six monitoring sites, the presence of permafrost is unlikely below 4550 m a.s.l. but likely above 5250 m a.s.l. on Mt. Ojos del Salado. In addition, the active layer becomes extremely thin around 6750 m a.s.l.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/ATMOS13122055", "year": 2022, "title": "Investigations on the Global Spread of the Hunga Tonga-Hunga Ha'apai Volcanic Eruption Using Space-Based Observations and Lagrangian Transport \u2026", "abstract": "On 15 January 2022, the Hunga Tonga-Hunga Haapai (HTHH) (175.38 W, 20.54 S) volcano erupted explosively. It is considered the most explosive volcanic eruption during the past 140 years. The HTHH volcanic eruption caused intense ripples, Lamb waves, and gravity waves in the atmosphere which encircled the globe several times, as reported by different studies. In this study, using OMI, SAGE-III/ISS, and CALIPSO satellite observations, we investigated the spread of the volcanic SO2 cloud due to the HTHH eruption and subsequent formation of sulfuric acid clouds in the stratosphere. It took about 1921 days for the stratospheric SO2 injections of the HTHH to encircle the globe longitudinally due to a dominant westward jet with wind speeds of ~2500 km/day, and it slowly dispersed over the whole globe within several months due to poleward spread. The formation of sulfuric acid clouds intensified after about a month, causing the more frequent occurrence of high aerosol optical depth elevated layers in the stratosphere at an altitude of about 2026 km. This study deals with the dynamics of volcanic plume spread in the stratosphere, knowledge of which is essential in estimating the accurate radiative effects caused by perturbations in the earthatmosphere system due to a volcanic eruption. In addition, this knowledge provides important input for studies related to the geo-engineering of the earths atmosphere by injecting particulates and gases into the stratosphere.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3389/FEART.2021.765668", "year": 2021, "title": "Inflating shallow plumbing system of Bezymianny volcano, Kamchatka, studied by InSAR and seismicity data prior to the 20 December 2017 eruption", "abstract": "Explosive eruptions at steep-sided volcanoes may develop with complex precursor activity occurring in a poorly-understood magma plumbing system so that timelines and possible interactions with the geologic surrounding are often unresolved. Here we investigate the episode prior to the energetic December 20, 2017 eruption at Bezymianny volcano, Kamchatka. We compare degassing activity inferred from time-lapse camera images, seismicity and real-time seismic amplitude (RSAM) data derived from a temporary station network, as well as high-resolution InSAR displacement maps. Results show that the first changes can be identified in low-frequency seismicity and degassing at least 90 days before the eruption, while the first volcano-tectonic (VT) seismicity occurred 50 days before the eruption. Coinciding with significant changes of the RSAM, surface displacements affect the volcanic flanks at least 9 days prior to the eruption. Inversion modeling of the pre-eruptive surface deformation as well as deflation-type, co-eruptive surface changes indicate the presence of a shallow and transient reservoir. We develop a conceptual model for Bezymianny volcano initiating with deep seismicity, followed by shallow events, rockfalls, steaming and an inflating reservoir. The eruption is then associated with subsidence, caused by deflation of the same reservoir. This sequence and conceivable causality of these observations are providing a valuable contribution to our understanding of the shallow magma plumbing system beneath Bezymianny and may have relevance for volcano monitoring and early warning strategies at similar volcanoes elsewhere.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1080/01431161.2022.2068360", "year": 2022, "title": "The first evaluation of the FY-3D/MERSI-2 sensor's thermal infrared capabilities for deriving land surface temperature in volcanic regions: a case study of Mount Etna", "abstract": "In November 2017, the China Meteorological Administration launched a new polar orbiting satellite in its Fengyun (FY) series: FY-3D. With its main purpose being the collection of meteorological data, FY-3D featured a comprehensive payload that is equally exploitable by various Earth Science disciplines. One of its sensors, the MEdium Resolution Spectral Imager-2 (MERSI-2), provides visible and infrared imagery at spatial resolutions of 250 1000 m. These characteristics make MERSI-2 suitable for volcanological remote sensing and make it comparable to the National Aeronautics and Space Administrations (NASAs) Moderate Resolution Imaging Spectroradiometer (MODIS) sensors which themselves, have been widely used in volcanological applications. This paper evaluates the first clear and near-coincident MODIS MERSI-2 images of Mount Etna (Italy) during an active volcanic phase in 2019 and in turn, provides the first assessment of MERSI-2s utility in observing volcanic activity in the Thermal InfraRed (TIR). To ensure the comparability of both scenes, data from each were converted to Land Surface Temperature (LST) and comparisons were encouraging, with an r2 of 0.92, a mean temperature discrepancy of 0.26 K and a root mean squared error of 0.75 K. Having ascertained comparability, we focussed on the absolute temperatures detected at the eruption site, with the highest being 317.3 K and 328.1 K for MODIS and MERSI-2, respectively. The 20 minute gap between the acquisitions is the most likely the cause of this temperature discrepancy, suggesting variations in lava effusion rates and activity were occurring at Mount Etna over such timescales. This study confirms the applicability of MERSI-2 for observing volcanic activity and emphasises the significance of TIR volcanic monitoring and the importance that additional spaceborne platforms might have in reducing temporal gaps between image acquisitions. Given its unique characteristics, future studies should investigate the applicability of MERSI-2 in more varied volcanic settings.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1130/G48019.1", "year": 2021, "title": "Geochronology of volcanically associated hydrocarbon charge in the pre-salt carbonates of the Namibe Basin, Angola", "abstract": "In volcanic rifted margins, the timing of hydrocarbon charge is difficult to predict, but is important in understanding fluid genesis. We investigated whether igneous activity was linked to hydrocarbon charge in the prolific South Atlantic pre-salt petroleum system. To do this, we applied in situ carbonate U-Pb geochronology, a relatively novel tool for dating hydrocarbon migration, to bituminous veins in pre-salt travertines from the rifted onshore Namibe Basin (Angola). To test if fluid flow was synchronous with known volcanic pulses, we also obtained new 40Ar/39Ar geochronology from a nearby volcanic complex. Bitumen is associated with calcite in a first generation of veins and vugs, and with dolomite in younger veins. The dated calcite veins yielded a pooled U-Pb age of 86.2 2.4 Ma, which overlaps the volcanism 40Ar/39Ar age of 89.9 1.8 Ma. The overlapping dates and the localized bitumen occurrence around the dated volcanic center show a clear genetic relationship between Late Cretaceous igneous activity and hydrocarbon charge. The dolomite was dated at 56.8 4.8 Ma, revealing a previously unknown Paleocene/Eocene fluid-flow phase in the basin.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S00024-022-03172-Z", "year": 2022, "title": "Atmospheric and Ionospheric Signatures Associated with the 15 January 2022 Cataclysmic Hunga-Tonga Volcanic Eruption: A Multi-layer Observation", "abstract": "The Hunga-Tonga volcanic eruption occurred on 15 January 2022 generated different modes of atmospheric and ionospheric waves. Using the Geostationary Operational Environment Satellite-17 (GOES-17), Aqua and Global Positioning System (GPS) satellite observations, an atmospheric and ionospheric multi-layer study of the Tonga volcano induced signatures over the New Zealand region is performed. The visible and infrared channel data of GOES-17 and Atmospheric Infrared Sounder (AIRS) data from NASA Aqua satellite confirm the presence of a highly convective zone and occurrence of concentric Lamb and gravity waves at lower atmospheric altitudes. The Total Electron Content (TEC) derived from 175 GPS stations covering the entire New Zealand region brings out two dominant modes of Travelling Ionospheric Disturbances (TIDs) having periodicity between 30 and 50 min. These two different modes having the phase speeds of 542 m/s and 354 m/s are allied to atmospheric gravity waves and Lamb wave triggered gravity waves respectively and are observed to propagate towards the south-west direction over the New Zealand region.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.QUAINT.2020.08.010", "year": 2021, "title": "Climate disaster and the resilience of local maritime networks: Two examples from the Aegean Bronze Age", "abstract": "This paper investigates changing patterns of maritime small-world networks among the Cycladic islands of the southern Aegean Sea in the context of two climate disasters in the Bronze Age (ca. 3200 BCE - 1100 BCE): the 4.2 ka event at the end of the Early Bronze Age and the eruption of Thera in the late 17th century BCE in the Late Bronze Age. The 4.2 ka event is a period where changing environmental conditions including landscape degradation, deforestation, and increased drought correlate with drastically reduced maritime connectivity and increased settlement isolation. Previous archaeological study of the eruption of the Theran volcano (Santorini) has shown the persistence of regional-scale communication networks for a period of up to a century after the eruption. This paper examines the effect of the eruption on local-scale maritime networks. The archaeological study of both climate events is complicated by chronological discrepancies and, in the case of the 4.2 ka event, reliance on indirect environmental data. This paper addresses the questions: a) what effect did these two climate disasters have on small-world maritime networks in the Bronze Age Cyclades, and b) how did the island inhabitants adapt within a context of disruptive environmental phenomena? GIS modeling reveals that small-world networks in the Early Bronze Age Cyclades were substantially altered in the face of the 4.2 ka climate event, while in response to the eruption of Thera, small-world networks were resilient. Variables influencing the differing network responses include the temporality of the climate disasters, the availability of the sail as a technology of resilience, and varying environmental and social vulnerabilities.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-22-14957-2022", "year": 2022, "title": "The evolution and dynamics of the Hunga TongaHunga Ha'apai sulfate aerosol plume in the stratosphere", "abstract": "Abstract. We use a combination of spaceborne instruments to study the unprecedented stratospheric plume after the Tonga eruption of 15 January 2022. The aerosol plume was initially formed of two clouds at 30 and 28 km, mostly composed of submicron-sized sulfate particles, without ash, which is washed out within the first day following the eruption. The large amount of injected water vapour led to a fast conversion of SO2 to sulfate aerosols and induced a descent of the plume to 2426 km over the first 3 weeks by radiative cooling. Whereas SO2 returned to background levels by the end of January, volcanic sulfates and water still persisted after 6 months, mainly confined between 35 S and 20 N until June due to the zonal symmetry of the summer stratospheric circulation at 2226 km. Sulfate particles, undergoing hygroscopic growth and coagulation, sediment and gradually separate from the moisture anomaly entrained in the ascending branch BrewerDobson circulation. Sulfate aerosol optical depths derived from the IASI (Infrared Atmospheric Sounding Interferometer) infrared sounder show that during the first 2 months, the aerosol plume was not simply diluted and dispersed passively but rather organized in concentrated patches. Space-borne lidar winds suggest that those structures, generated by shear-induced instabilities, are associated with vorticity anomalies that may have enhanced the duration and impact of the plume.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1144/JGS2022-064", "year": 2022, "title": "Magma accumulation underneath Laacher See volcano from detrital zircon in modern streams", "abstract": "The detrital zircon grains from two catchments in the East Eifel Volcanic Field consist of crystals sourced from proximal deposits of Quaternary trachyticphonolitic volcanic centres, Hocheifel Paleogene trachytic rocks and the Paleozoic basement. The outcrop patterns indicate the derivation of a significant detrital zircon population from deposits of the c. 13 ka Lower and Upper Laacher See Tephra. Intercalated Middle Laacher See Tephra, consisting of valley-filling ignimbrites, by contrast, is a minor zircon source despite thick ignimbrite deposits in one of the catchments. This reflects zircon undersaturation in the hotter and less evolved phonolite tapped from deeper parts of the magma reservoir as the eruption unfolded, as well as fewer antecrysts recycled from the plutonic carapace. A previously unrecognized zircon age population of c. 63 ka, mostly derived from Lower Laacher See Tephra, marks the onset of the presence of evolved magma at the top of the reservoir. Correlative Hf and O isotopic analysis reveals significant crustal interactions during phonolite differentiation in a shallow reservoir, with the assimilation of cogenetic, but hydrothermally modified, plutonic margins. Raman spectra indicate that magmatically heated crustal zircon xenocrysts are absent. Detrital zircon can thus provide more integrated insights into the evolution of Quaternary magma systems than the punctuated sampling of volcanic or cogenetic plutonic rocks.Supplementary material: Data tables presenting UTh, UPb, OHf and Raman geochronology results are available at https://doi.org/10.6084/m9.figshare.c.6123823", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1080/09853111.2021.1883314", "year": 2021, "title": "An oxidised intrusion-related origin in the controversial Jiaodong gold province (China) for the Shicheng Au-Cu deposit", "abstract": "The Shicheng Au-Cu deposit is hosted in the late Early Cretaceous Sanfoshan pluton within the Muping-Rushan (Mu-Ru) metallogenic belt, southeast Jiaodong. The deposit is characterised by Au-Cu bearing quartz-carbonate-sulphide veins that illustrate overprinting sheeted-like and breccia styles. Paragenetically-later veins contain Pb-Zn-(Cu) metal association, suggesting metal zonation at the deposit scale. Quartz from Shicheng shows the cathodoluminescence (CL) textures characteristic of hydrothermal systems with a magmatic influence and exhibits a similar quartz generations sequence. Moreover, this study presents a later overprinting mineralising event, characterised by quartz veins that contain As-rich pyrite, at the Jinqingding deposit in the middle part of the Mu-Ru belt. Jinqingding has a young mineralisation age that overlaps the emplacement age of the Sanfoshan pluton. Quartz from these veins at Jinqingding shows CL textures like those of the Shicheng deposit. The Sanfoshan pluton evolved from highly oxidised, high-K calc-alkaline, I-type magmatism. The early phases of the Sanfoshan pluton have K/Rb, Rb/Sr, and Fe2O3/FeO ratios that indicate moderately evolved, less fractionated, and highly oxidised magma, respectively, favouring Au-chalcophile metal association. Therefore, the Shicheng deposit and the overprinting mineralising event at Jinqingding may reasonably represent the products of an oxidised magmatic-hydrothermal system associated with the Sanfoshan-forming magmatism.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/AMT-14-3673-2021", "year": 2021, "title": "Volcanic SO2 effective layer height retrieval for the Ozone Monitoring Instrument (OMI) using a machine-learning approach", "abstract": "Abstract. Information about the height and loading of sulfur dioxide (SO2) plumes from volcanic eruptions is crucial for aviation safety and for assessing the effect of sulfate aerosols on climate. While SO2 layer height has been successfully retrieved from backscattered Earthshine ultraviolet (UV) radiances measured by the Ozone Monitoring Instrument (OMI), previously demonstrated techniques are computationally intensive and not suitable for near-real-time applications. In this study, we introduce a new OMI algorithm for fast retrievals of effective volcanic SO2 layer height. We apply the Full-Physics Inverse Learning Machine (FP_ILM) algorithm to OMI radiances in the spectral range of 310330 nm. This approach consists of a training phase that utilizes extensive radiative transfer calculations to generate a large dataset of synthetic radiance spectra for geophysical parameters representing the OMI measurement conditions. The principal components of the spectra from this dataset in addition to a few geophysical parameters are used to train a neural network to solve the inverse problem and predict the SO2 layer height. This is followed by applying the trained inverse model to real OMI measurements to retrieve the effective SO2 plume heights. The algorithm has been tested on several major eruptions during the OMI data record. The results for the 2008 Kasatochi, 2014 Kelud, 2015 Calbuco, and 2019 Raikoke eruption cases are presented here and compared with volcanic plume heights estimated with other satellite sensors. For the most part, OMI-retrieved effective SO2 heights agree well with the lidar measurements of aerosol layer height from CloudAerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and thermal infrared retrievals of SO2 heights from the infrared atmospheric sounding interferometer (IASI). The errors in OMI-retrieved SO2 heights are estimated to be 11.5 km for plumes with relatively large SO2 signals (>40 DU). The algorithm is very fast and retrieves plume height in less than 10 min for an entire OMI orbit.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2022GL100982", "year": 2022, "title": "Stratospheric Circulation Changes Associated With the Hunga Tonga\u2010Hunga Ha'apai Eruption", "abstract": "The 15 January 2022 eruption of the Hunga Tonga-Hunga Ha'apai underwater volcano (20.5\u00b0S, 175.4\u00b0W) injected a record amount of water directly into the stratosphere. This study attempts to quantify this impact on the temperature, as well as the subsequent changes to the stratospheric circulation, during the months following the eruption based on reanalysis fields. The extreme nature of the temperature, wind, and circulation changes are tracked through comparisons of the first six months of 2022 with the previous 42 years. Examination of the data assimilation process shows that at 20 hPa the thermal observations are forcing significant cooling, compensating for the absence of the excess stratospheric moisture in the model used for the reanalysis. In response to this cooling the atmosphere adjusts by creating strong westerly winds above the temperature anomaly and large changes to the downward and poleward mean meridional circulation.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1038/S41586-020-2172-5", "year": 2020, "title": "Extreme rainfall triggered the 2018 rift eruption at K\u012blauea Volcano", "abstract": "The May 2018 rift intrusion and eruption of Kilauea Volcano, Hawaii, represented one of its most extraordinary eruptive sequences in at least 200 years, yet the trigger mechanism remains elusive1. The event was preceded by several months of anomalously high precipitation. It has been proposed that rainfall can modulate shallow volcanic activity2,3, but it remains unknown whether it can have impacts at the greater depths associated with magma transport. Here we show that immediately before and during the eruption, infiltration of rainfall into Kilauea Volcanos subsurface increased pore pressure at depths of 1 to 3 kilometres by 0.1 to 1 kilopascals, to its highest pressure in almost 50 years. We propose that weakening and mechanical failure of the edifice was driven by changes in pore pressure within the rift zone, prompting opportunistic dyke intrusion and ultimately facilitating the eruption. A precipitation-induced eruption trigger is consistent with the lack of substantial precursory summit inflation, showing that this intrusionunlike otherswas not caused by the forceful intrusion of new magma into the rift zone. Moreover, statistical analysis of historic eruption occurrence suggests that rainfall patterns contribute substantially to the timing and frequency of Kilaueas eruptions and intrusions. Thus, volcanic activity can be modulated by extreme rainfall triggering edifice rock failurea factor that should be considered when assessing volcanic hazards. Notably, the increasingly extreme weather patterns associated with ongoing anthropogenic climate change could increase the potential for rainfall-triggered volcanic phenomena worldwide.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/BG-15-6087-2018", "year": 2018, "title": "Life cycle of bamboo in the southwestern Amazon and its relation to fire events", "abstract": "Abstract. Bamboo-dominated forests comprise 1 % of the world's forests and 3 % of the Amazon forests. The Guadua spp. bamboos that dominate the southwest Amazon are semelparous; thus flowering and fruiting occur once in a lifetime before death. These events occur in massive spatially organized patches every 28 years and produce huge quantities of necromass. The bamboofire hypothesis argues that increased dry fuel after die-off enhances fire probability, creating opportunities that favor bamboo growth. In this study, our aim is to map the bamboo-dominated forests and test the bamboofire hypothesis using satellite imagery. Specifically, we developed and validated a method to map the bamboo die-off and its spatial distribution using satellite-derived reflectance time series from the Moderate Resolution Imaging Spectroradiometer (MODIS) and explored the bamboofire hypothesis by evaluating the relationship between bamboo die-off and fires detected by the MODIS thermal anomalies product in the southwest Amazon. Our findings show that the near-infrared (NIR) is the most sensitive spectral interval to characterize bamboo growth and cohort age. Automatic detection of historical bamboo die-off achieved an accuracy above 79 %. We mapped and estimated 15.5 million ha of bamboo-dominated forests in the region. The bamboofire hypothesis was not supported because only a small fraction of bamboo areas burned during the analysis timescale, and, in general, bamboo did not show higher fire probability after the die-off. Nonetheless, fire occurrence was 45 % higher in dead than live bamboo in drought years, associated with ignition sources from land use, suggesting a bamboohumanfire association. Although our findings show that the observed fire was not sufficient to drive bamboo dominance, the increased fire occurrence in dead bamboo in drought years may contribute to the maintenance of bamboo and potential expansion into adjacent bamboo-free forests. Fire can even bring deadly consequences to these adjacent forests under climate change effects.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.JAG.2018.08.010", "year": 2018, "title": "Quantifying spatial-temporal changes of tea plantations in complex landscapes through integrative analyses of optical and microwave imagery", "abstract": "High demand for tea has driven the expansion of tea plantations in the tropical and subtropical regions over the past few decades. Tea plant cultivation promotes economic development and creates job opportunities, but tea plantation expansion has significant impacts on biodiversity, carbon and water cycles, and ecosystem services. Mapping the spatial distribution and extent of tea plantations in a timely fashion is crucial for land use management and policy making. In this study, we mapped tea plantation expansion in Menghai County, Yunnan Province, China. We analyzed the structure and features of major land cover types in this tropical and subtropical region using (1) the HH and HV gamma-naught imagery from the Advanced Land Observation Satellite (ALOS) Phased Array L-band Synthetic Aperture Radar (PALSAR) and (2) time series Landsat TM/ETM+/OLI imagery. Tea plantation maps for 2010 and 2015 were generated using the pixel-based support vector machine (SVM) approach at 30 m resolution, which had high user/producer accuracies of 83.58%/91.67% and 87.50%/90.83%, respectively. The resultant maps show that tea plantation area increased by 33.56% (9335 ha), from 27,817 ha in 2010 to 37,152 ha in 2015. The additional tea plantation area was mainly converted from forest (32.50%) and cropland (67.50%). The results showed that the combination of PALSAR and optical data performed better in tea plantation mapping than using optical data only. This study provides a promising new approach to identify and map tea plantations in complex tropical landscapes at high spatial resolution.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ACP-22-15817-2022", "year": 2022, "title": "Optimizing 4 years of CO2 biospheric fluxes from OCO-2 and in situ data in TM5: fire emissions from GFED and inferred from MOPITT CO data", "abstract": "Abstract. Column mixing ratio of carbon dioxide (CO2) data alone do not provide enough information for source attribution. Carbon monoxide (CO) is a product of inefficient combustion often co-emitted with CO2. CO data can then provide a powerful constraint on fire emissions, supporting more accurate estimation of biospheric CO2 fluxes. In this framework and using the chemistry transport model TM5, a CO inversion using Measurements of Pollution in The Troposphere (MOPITT) v8 data is performed to estimate fire emissions which are then converted into CO2 fire emissions (called FIREMo) through the use of the emission ratio. These optimized CO2 fire emissions are used to rebalance the CO2 net ecosystem exchange (NEEMo) and respiration (RhMo) with the global CO2 growth rate. Subsequently, in a second step, these rebalanced fluxes are used as priors for a CO2 inversion to derive the NEE and ocean fluxes constrained either by the Orbiting Carbon Observatory 2 (OCO-2) v9 or by in situ (IS) CO2 data. For comparison purpose, we also balanced the respiration using fire emissions from the Global Fire Emissions Database (GFED) version 3 (GFED3) and version 4.1s (GFED4.1s). We hence study the impact of CO fire emissions in our CO2 inversions at global, latitudinal, and regional scales over the period 20152018 and compare our results to the two other similar approaches using GFED3 (FIRE3) and GFED4.1s (FIRE4) fires, as well as with an inversion using both CarnegieAmesStanford Approach (CASA)-GFED3 NEE and GFED3 fire priors (priorCMS). After comparison at the different scales, the inversions are evaluated against Total Carbon Column Observing Network (TCCON) data. Comparison of the flux estimates shows that at the global scale posterior net flux estimates are more robust than the different prior flux estimates. However, at the regional scale, we can observe differences in fire emissions among the priors, resulting in differences among the NEE prior emissions. The derived NEE prior emissions are rebalanced in concert with the fires. Consequently, the differences observed in the NEE posterior emissions are a result of the balancing with fires and the constraints provided by CO2 observations. Tropical net flux estimates from in situ inversions are highly sensitive to the prior flux assumed, of which fires are a significant component. Slightly larger net CO2 sources are derived with posterior fire emissions using either FIRE4 or FIREMo in the OCO-2 inversion, in particular for most tropical regions during the 2015 El Nino year. Similarly, larger net CO2 sources are also derived with posterior fire emissions in the in situ data inversion for Tropical Asia. Evaluation with CO2 TCCON data shows lower biases with the three rebalanced priors than with the prior using CASA-GFED3. However, posteriors have average bias and scatter very close each other, making it difficult to conclude which simulation performs better than the other. We observe that the assimilated CO2 data have a strong influence on the global net fluxes among the different inversions. Inversions using OCO-2 (or IS) data have similar emissions, mostly as a result of the observational constraints and to a lesser extent because of the fire prior used. But results in the tropical regions suggest net flux sensitivity to the fire prior for both the IS and OCO-2 inversions. Further work is needed to improve prior fluxes in tropical regions where fires are a significant component. Finally, even if the inversions using the FIREMo prior did enhance the biases over some TCCON sites, it is not the case for the majority of TCCON sites. This study consequently pushes forward the development of a COCO2 joint inversion with multi-observations for a possible stronger constraint on posterior CO2 fire and biospheric emissions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/ACP-22-12803-2022", "year": 2022, "title": "Aerosol size distribution changes in FIREX-AQ biomass burning plumes: the impact of plume concentration on coagulation and OA condensation/evaporation", "abstract": "Abstract. The evolution of organic aerosol (OA) and aerosol size\ndistributions within smoke plumes is uncertain due to the variability in\nrates of coagulation and OA condensation/evaporation between different smoke\nplumes and at different locations within a single plume. We use aircraft\ndata from the FIREX-AQ campaign to evaluate differences in evolving aerosol\nsize distributions, OA, and oxygen to carbon ratios (O:C) between and within\nsmoke plumes during the first several hours of aging as a function of smoke\nconcentration. The observations show that the median particle diameter\nincreases faster in smoke of a higher initial OA concentration (>1000 g m3), with diameter growth of over 100 nm in 8 h despite generally having a net decrease in OA enhancement\nratios than smoke of a lower initial OA concentration (<100 g m3), which had net increases in OA. Observations of OA and O:C\nsuggest that evaporation and/or secondary OA formation was greater in less\nconcentrated smoke prior to the first measurement (557 min after\nemission). We simulate the size changes due to coagulation and dilution and\nadjust for OA condensation/evaporation based on the observed changes in OA.\nWe found that coagulation explains the majority of the diameter growth, with\nOA evaporation/condensation having a relatively minor impact. We found that\nmixing between the core and edges of the plume generally occurred on\ntimescales of hours, slow enough to maintain differences in aging between\ncore and edge but too fast to ignore the role of mixing for most of our cases.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/NENERGY.2016.140", "year": 2016, "title": "Identification of advantageous electricity generation options in sub-Saharan Africa integrating existing resources", "abstract": "Pioneering approaches are needed to accelerate universal access to electricity while simultaneously transitioning to reliable, sustainable and affordable energy systems. In sub-Saharan Africa (SSA), the challenges lie in attracting the private sector to complement public investments. Here, we present an integrated \u2018low-hanging-fruit\u2019 approach aimed at boosting private investment and speeding up the deployment of renewable energy systems in SSA. We analyse the potential of existing energy infrastructure, where a significant upfront investment has already been made, to be exploited for electricity generation. We develop a comprehensive methodology to identify and select suitable locations in SSA and estimate their potential for exploitation. These locations have been further analysed in terms of power capacity potential, electricity output, investments needed and population to be benefited. This strategy to attract additional finance can easily be reproduced, engaging private investors while simultaneously helping to achieve the United Nations (UN) Sustainable Development Goals on energy.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1038/S43247-022-00517-3", "year": 2022, "title": "Cloud processing and weeklong ageing affect biomass burning aerosol properties over the south-eastern Atlantic", "abstract": "Southern Africa produces a third of global biomass burning emissions, which have a long atmospheric lifetime and influence regional radiation balance and climate. Here, we use airmass trajectories to link different aircraft observations to investigate the evolution of biomass-burning aerosols during their westward transport from Southern Africa over the south-eastern Atlantic, where a semi-permanent stratocumulus cloud deck is located. Our results show secondary organic aerosol formation during the initial 3 days of transport, followed by decreases in organic aerosol via photolysis before reaching equilibrium. Aerosol absorption wavelength dependency decreases with ageing, due to an increase in particle size and photochemical bleaching of brown carbon. Cloud processing, including aqueous-phase reaction and scavenging, contributes to the oxidation of organic aerosols, while it strongly reduces large diameter particles and single-scattering albedo of biomass burning aerosols. Together, these processes resulted in a marine boundary layer with fewer yet more oxidized and absorbing aerosols.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1029/2021JD035925", "year": 2022, "title": "Australian Fire Emissions of Carbon Monoxide Estimated by Global Biomass", "abstract": "Australian fires are a primary driver of variability in Australian atmospheric composition and contribute significantly to regional and global carbon budgets. However, biomass burning emissions from Australia remain highly uncertain. In this work, we use surface in situ, ground-based total column and satellite total column observations to evaluate the ability of two global models (GEOS-Chem and ACCESS-UKCA) and three global biomass burning emission inventories (FINN1.5, GFED4s, and QFED2.4) to simulate carbon monoxide (CO) in the Australian atmosphere. We find that emissions from northern Australia savanna fires are substantially lower in FINN1.5 than in the other inventories. Model simulations driven by FINN1.5 are unable to reproduce either the magnitude or the variability of observed CO in northern Australia. The remaining two inventories perform similarly in reproducing the observed variability, although the larger emissions in QFED2.4 combined with an existing high bias in the southern hemisphere background lead to large CO biases. We therefore recommend GFED4s as the best option of the three for global modeling studies with focus on Australia or the Southern Hemisphere. Near fresh fire emissions, the higher resolution ACCESS-UKCA model is better able to simulate surface CO than GEOS-Chem, while GEOS-Chem captures more of the observed variability in the total column and remote surface air measurements. We also show that existing observations in Australia can only partially constrain global model estimates of biomass burning. Continuous measurements in fire-prone parts of Australia are needed, along with updates to global biomass burning inventories that are validated with Australian data.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1002/2016JD026421", "year": 2017, "title": "Biomass burning aerosol transport and vertical distribution over the South AfricanAtlantic region", "abstract": "Optically thick smoke aerosol plumes originating from biomass burning (BB) in the southwestern African Savanna during the austral spring are transported westward by the free tropospheric winds to primarily overlie vast stretches of stratocumulus cloud decks in the southeast Atlantic. We evaluated the simulations of long-range transport of BB aerosol by the Goddard Earth Observing System (GEOS-5) and four other global aerosol models over the complete South African-Atlantic region using Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations to find any distinguishing or common model biases. Models, in general, captured the vertical distribution of aerosol over land but exhibited some common features after long-range transport of smoke plumes that were distinct from that of CALIOP. Most importantly, the model-simulated BB aerosol plumes quickly descend to lower levels just off the western coast of the continent, while CALIOP data suggest that smoke plumes continue their horizontal transport at elevated levels above the marine boundary layer. This is crucial because the sign of simulated aerosol semidirect effect can change depending on whether the bulk of the absorbing aerosols is present within or above the cloud levels in a model. The levels to which the aerosol plumes get subsided and the steepness of their descent vary amongst the models and amongst the different subregions of the domain. Investigations into possible causes of differences between GEOS-5 and CALIOP aerosol transport over the ocean revealed a minimal role of aerosol removal process representation in the model as opposed to model dynamics.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ECONLET.2022.110446", "year": 2022, "title": "Unintended consequences of Indian groundwater preservation law on crop residue burning", "abstract": "This paper examines the unintended consequences of a policy aimed at improving the groundwater level on crop residue burning in India. The Preservation of Subsoil Water Act, 2009 implemented in two Indian states bans the transplantation of paddy before mid-June to preserve groundwater. Theoretically, this leaves a short window of time for clearing the field before the next crop and thus increases the likelihood of farmers adopting time-saving methods like crop residue burning. Using a difference-in-difference framework we find that the ban results in both delay and an increase in crop residue burning in the winter months.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/BG-16-1629-2019", "year": 2019, "title": "Estimation of emissions from biomass burning in China (2003\u20132017) based on MODIS fire radiative energy data", "abstract": "Abstract. Biomass burning plays a significant role in air pollution and climate change. In this study, we used a method based on fire radiative energy (FRE) to develop a biomass burning emission inventory for China from 2003 to 2017. Daily fire radiative power (FRP) data derived from 1 km MODIS Thermal Anomalies/Fire products (MOD14/MYD14) were used to calculate FRE and combusted biomass. Available emission factors were assigned to four biomass burning types: forest, cropland, grassland, and shrubland fires. The farming system and crop types in different temperate zones were taken into account in this research. Compared with traditional methods, the FRE method was found to provide a more reasonable estimate of emissions from small fires. The estimated average annual emission ranges, with a 90 % confidence interval, were 91.4 (72.7108.8) Tg CO2 yr1, 5.0 (2.37.8) Tg CO yr1, 0.24 (0.050.48) Tg CH4 yr1, 1.43 (0.532.35) Tg NMHC yr1, 0.23 (0.050.45) Tg NOx yr1, 0.09 (0.020.17) Tg NH3 yr1, 0.03 (0.010.05) Tg SO2 yr1, 0.04 (0.010.08) Tg BC yr1, 0.27 (0.070.49) Tg OC yr1, 0.51 (0.190.84) Tg PM2.5 yr1, 0.57 (0.151.05) Tg PM10 yr1, where NMHC, BC, and OC are nonmethane hydrocarbons, black carbon, and organic carbon, respectively. Forest fires are determined to be the primary contributor to open fire emissions, accounting for 45 % of the total CO2 emissions (average 40.8 Tg yr1). Crop residue burning ranked second place with a large portion of 39 % (average 35.3 Tg yr1). During the study period, emissions from forest and grassland fires showed a significant downward trend. Crop residue emissions continued to rise during 20032015 but dropped by 42 % in 20152016. Emissions from shrubland were negligible and little changed. Forest and grassland fires are concentrated in northeastern China and southern China, especially in the dry season (from October to March of the following year). Plain areas with high crop yields, such as the North China Plain, experienced high agricultural fire emissions in harvest seasons. Most shrubland fires were located in Yunnan and Guangdong provinces. The resolution of our inventory (daily, 1 km) is much higher than previous inventories, such as GFED4s and GFASv1.0. It could be used in global and regional air quality modeling.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1177/0022343314558102", "year": 2015, "title": "Explosive connections? Mass media, social media, and the geography of collective violence in African states", "abstract": "Growing evidence indicates that the diffusion of information and communication technologies (ICTs) can substantially alter the contours of collective violence in developing nations. However, empirical investigations of such effects have generally been hampered by an inability to systematically measure geographic variation in ICT penetration, across multiple technologies and multiple countries. In this article, I show that geo-referenced household surveys can be used to estimate subnational differences in the spatial reach of radio and cellular communications infrastructures in 24 African states. By combining these estimates with geo-referenced measures of the location of disaggregated events of collective violence, I show that there are important differences between centralized mass communication technologies such as radios that foster vertical linkages between state and society, and decentralized social communication technologies such as cell phones that foster horizontal linkages between the members of a society. The evidence demonstrates that the geographic reach of mass media penetration generates substantial pacifying effects, while the reach of social media penetration generates substantial increases in collective violence, especially in areas lacking access to mass media infrastructure. I argue that these findings are consistent with a theory of ICT effects which focuses on the strengthening and weakening of economies of scale in the marketplace of ideas.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ACP-21-14815-2021", "year": 2021, "title": "Observations of supermicron-sized aerosols originating from biomass burning in southern Central Africa", "abstract": "Abstract. During the 3 years of the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) campaign, the NASA Orion P-3 was equipped with a 2D stereo (2D-S) probe that imaged particles with maximum dimension (D) ranging from 10 < D < 1280 m. The 2D-S recorded supermicron-sized aerosol particles (SAPs) outside of clouds within biomass burning plumes during flights over the southeastern Atlantic off Africa's coast. Numerous SAPs with 10 < D < 1520 m were observed in 2017 and 2018 at altitudes between 1230 and 4000 m, 1000 km from the coastline, mostly between 711 S. No SAPs were observed in 2016 as flights were conducted further south and further from the coastline. Number concentrations of refractory black carbon (rBC) measured by a single particle soot photometer ranged from 200 to 1200 cm3 when SAPs were observed. Transmission electron microscopy images of submicron particulates, collected on Holey carbon grid filters, revealed particles with potassium salts, black carbon (BC), and organics. Energy-dispersive X-ray spectroscopy spectra also detected potassium, a tracer for biomass burning. These measurements provided evidence that the submicron particles originated from biomass burning. NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) 3 d back trajectories show a source in northern Angola for times when large SAPs were observed. Fire Information for Resource Management System (FIRMS) Moderate Resolution Imaging Spectroradiometer (MODIS) 6 active fire maps showed extensive biomass burning at these locations. Given the back trajectories, the high number concentrations of rBC, and the presence of elemental tracers indicative of biomass burning, it is hypothesized that the SAPs imaged by the 2D-S are examples of BC aerosol, ash, or unburned plant material.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-18-15261-2018", "year": 2018, "title": "Large simulated radiative effects of smoke in the south-east Atlantic", "abstract": "Abstract. A 12001200 km2 area of the tropical South Atlantic Ocean near Ascension Island is studied with the HadGEM climate model at convection-permitting and global resolutions for a 10-day case study period in August 2016. During the simulation period, a plume of biomass burning smoke from Africa moves into the area and mixes into the clouds. At Ascension Island, this smoke episode was the strongest of the 2016 fire season.The region of interest is simulated at 4 km resolution, with no parameterised convection scheme. The simulations are driven by, and compared to, the global model. For the first time, the UK Chemistry and Aerosol model (UKCA) is included in a regional model with prognostic aerosol number concentrations advecting in from the global model at the boundaries of the region.Fire emissions increase the total aerosol burden by a factor of 3.7 and cloud droplet number concentrations by a factor of 3, which is consistent with MODIS observations. In the regional model, the inversion height is reduced by up to 200 m when smoke is included. The smoke also affects precipitation, to an extent which depends on the model microphysics. The microphysical and dynamical changes lead to an increase in liquid water path of 60 g m2 relative to a simulation without smoke aerosol, when averaged over the polluted period. This increase is uncertain, and smaller in the global model. It is mostly due to radiatively driven dynamical changes rather than precipitation suppression by aerosol.Over the 5-day polluted period, the smoke has substantial direct radiative effects of +11.4 W m2 in the regional model, a semi-direct effect of 30.5 W m2 and an indirect effect of 10.1 W m2. Our results show that the radiative effects are sensitive to the structure of the model (global versus regional) and the parameterization of rain autoconversion. Furthermore, we simulate a liquid water path that is biased high compared to satellite observations by 22 % on average, and this leads to high estimates of the domain-averaged aerosol direct effect and the effect of the aerosol on cloud albedo. With these caveats, we simulate a large net cooling across the region, of 27.6 W m2.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ENERGY.2017.12.051", "year": 2018, "title": "The increasing impact of weather on electricity supply and demand", "abstract": "Wind and solar power have experienced rapid cost declines and are being deployed at scale. However, their output variability remains a key problem for managing electricity systems, and the implications of multi-day to multi-year variability are still poorly understood. As other energy-using sectors are electrified, the shape and variability of electricity demand will also change. We develop an open framework for quantifying the impacts of weather on electricity supply and demand using the Renewables.ninja and DESSTINEE models. We demonstrate this using a case study of Britain using National Grid's Two Degrees scenario forwards to 2030. We find the British electricity system is rapidly moving into unprecedented territory, with peak demand rising above 70 GW due to electric heating, and intermittent renewable output exceeding demand as early as 2021. Hourly ramp-rates widen by 50% and year-to-year variability increases by 80%, showing why future power system studies must consider multiple years of data, and the influence of weather on both supply and demand. Our framework is globally applicable, and allows detailed scenarios of hourly electricity supply and demand to be explored using only limited input data such as annual quantities from government scenarios or broader energy systems models.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-20-15401-2020", "year": 2020, "title": "Constraining the relationships between aerosol height, aerosol optical depth and total column trace gas measurements using remote sensing and models", "abstract": "Abstract. Proper quantification of the aerosol vertical height is essential to constrain the atmospheric distribution and lifetime of aerosols, as well as their impact on the environment. We use globally distributed, daily averaged measurements of aerosol stereo heights of fire aerosols from the Multi-angle Imaging SpectroRadiometer (MISR) to understand the aerosol distribution. We also connect these results with a simple plume rise model and a new multi-linear regression model approach based on daily measurements of NO2 from OMI and CO from MOPITT to understand and model the global aerosol vertical height profile over biomass burning regions. First, plumes associated with the local dry-burning season at midlatitudes to high latitudes frequently have a substantial fraction lofted into the free troposphere and in some cases even the stratosphere. Second, plumes mainly associated with less-polluted regions in developing countries and heavily forested areas tend to stay closer to the ground, although they are not always uniformly distributed throughout the boundary layer. Third, plumes associated with more serious loadings of pollution (such as in Africa, Southeast Asia and northeast China) tend to have a substantial amount of smoke transported uniformly through the planetary boundary layer and up to around 3 km. Fourth, the regression model approach yields a better ability to reproduce the measured heights compared to the plume rise model approach. This improvement is based on a removal of the negative bias observed from the plume model approach, as well as a better ability to work under more heavily polluted conditions. However, over many regions, both approaches fail, requiring deeper work to understand the physical, chemical and dynamical reasons underlying the failure over these regions.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.SCITOTENV.2018.04.268", "year": 2018, "title": "Copper distribution in European topsoils: An assessment based on LUCAS soil survey", "abstract": "Copper (Cu) distribution in soil is influenced by climatic, geological and pedological factors. Apart from geological sources and industrial pollution, other anthropogenic sources, related to the agricultural activity, may increase copper levels in soils, especially in permanent crops such as olive groves and vineyards. This study uses 21,682 soil samples from the LUCAS topsoil survey to investigate copper distribution in the soils of 25 European Union (EU) Member States. Generalized Linear Models (GLM) were used to investigate the factors driving copper distribution in EU soils. Regression analysis shows the importance of topsoil properties, land cover and climate in estimating Cu concentration. Meanwhile, a copper regression model confirms our hypothesis that different agricultural management practices have a relevant influence on Cu concentration. Besides the traditional use of copper as a fungicide for treatments in several permanent crops, the combined effect of soil properties such as high pH, soil organic carbon and clay, with humid and wet climatic conditions favours copper accumulation in soils of vineyards and tree crops. Compared to the overall average Cu concentration of 16.85 mg kg1, vineyards have the highest mean soil Cu concentration (49.26 mg kg1) of all land use categories, followed by olive groves and orchards. Gaussian Process Regression (GPR) combined with kriging were used to map copper concentration in topsoils and to evidence the presence of outliers. GPR proved to be performant in predicting Cu concentration, especially in combination with kriging, accounting for 66% of Cu deviance. The derived maps are novel as they include information about the importance of topsoil properties in the copper mapping process, thus improving its accuracy. Both models highlight the influence of land management practices in copper concentration and the strong correlation between topsoil copper and vineyards.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1029/2018JD029336", "year": 2019, "title": "Desert Dust, Industrialization, and Agricultural Fires: Health Impacts of Outdoor Air Pollution in Africa", "abstract": "The African continent continuously experiences extreme aerosol load conditions, during which the World Health Organization clean air standard of 10 \u03bcg/m3 of PM2.5 mass is systematically exceeded. Africa holds the world largest source of desert dust emissions, undergoes strong industrial growth, and produces approximately a third of the Earth's biomass burning aerosol particles. Sub-Saharan biomass burning is driven by agricultural practices, such as burning fields and bushes in the postharvest season for fertilization, land management, and pest control. Thus, these emissions are predominantly anthropogenic. Here we use global atmospheric composition, climate, and health models to simulate the chemical composition of the atmosphere and calculate the mortality rates for Africa by distinguishing between purely natural, industrial/domestic, and biomass burning emissions. Air quality-related deaths in Africa rank within the top leading causes of death in Africa. Our results of 780,000 premature deaths annually point to the extensive health impacts of natural emissions, high mortality rate caused by industrialization in Nigeria and South Africa, and a smaller extent by fire emissions in Central and West Africa. In Africa, 43,000 premature deaths are linked to biomass burning mainly driven by agriculture. Our results also show that natural sources, in particular windblown dust emissions, have large impacts on air quality and human health in Africa.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSENV.2010.05.010", "year": 2010, "title": "Smoke emissions from biomass burning in a Mediterranean shrubland", "abstract": "Gaseous and particulate samples from the smoke from prescribed burnings of a shrub-dominated forest with some pine trees in Lousa Mountain, Portugal, in May 2008, have been collected. From the gas phase Fourier transform infrared (FTIR) measurements, an average modified combustion efficiency of 0.99 was obtained, suggesting a very strong predominance of flaming combustion. Gaseous compounds whose emissions are promoted in fresh plumes and during the flaming burning phase, such as CO2, acetylene and propene, produced emission factors higher than those proposed for savannah and tropical forest fires. Emission factors of species that are favoured by the smouldering phase (e.g. CO and CH4) were below the values reported in the literature for biomass burning in other ecosystems. The chemical composition of fine (PM2.5) and coarse (PM2.510) particles was achieved using ion chromatography (water-soluble ions), instrumental neutron activation analysis (trace elements) and a thermaloptical transmission technique (organic carbon and elemental carbon). Approximately 50% of the particulate mass was carbonaceous in nature with a clear dominance of organic carbon. The organic carbon-to-elemental carbon ratios up to 300, or even higher, measured in the present study largely exceeded those reported for fires in savannah and tropical forests. More than 30 trace elements and ions have been determined in smoke aerosols, representing in total an average contribution of about 7% to the PM10 mass.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1029/2021JD034916", "year": 2021, "title": "Biomass Burning Over the United States East Coast and Western North Atlantic Ocean: Implications for Clouds and Air Quality", "abstract": "Biomass burning (BB) aerosol events were characterized over the U.S. East Coast and Bermuda over the western North Atlantic Ocean (WNAO) between 2005 and 2018 using a combination of ground-based observations, satellite data, and model outputs. Days with BB influence in an atmospheric column (BB days) were identified using criteria biased toward larger fire events based on anomalously high AERONET aerosol optical depth (AOD) and MERRA-2 black carbon (BC) column density. BB days are present year-round with more in June-August (JJA) over the northern part of the East Coast, in contrast to more frequent events in March-May (MAM) over the southeast U.S. and Bermuda. BB source regions in MAM are southern Mexico and by the Yucatan, Central America, and the southeast U.S. JJA source regions are western parts of North America. Less than half of the BB days coincide with anomalously high PM2.5 levels in the surface layer, according to data from 14 IMPROVE sites over the East Coast. Profiles of aerosol extinction suggest that BB particles can be found in the boundary layer and into the upper troposphere with the potential to interact with clouds. Higher cloud drop number concentration and lower drop effective radius are observed during BB days. In addition, lower liquid water path is found during these days, especially when BB particles are present in the boundary layer. While patterns are suggestive of cloud-BB aerosol interactions over the East Coast and the WNAO, additional studies are needed for confirmation.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1111/SSQU.12930", "year": 2021, "title": "Trade Layoffs and Hate in the United States", "abstract": "ObjectiveRecent events (e.g., Brexit) have highlighted how globalization may foster hostility toward outgroups in developed democracies. Is trade competition systematically related to hate in the United States?MethodsI conduct a countylevel statistical analysis using data from the Trade Adjustment Assistance program, the FBI's Hate Crime Statistics database, and the Southern Poverty Law Center's hate group map over the period of 20032017.ResultsCounties with more traderelated layoffs tend to have more hate groups, though not hate crimes, even after accounting for changes in unemployment rates. The relationship between trade layoffs and hate groups is strongest in counties that have recently experienced larger decreases in the share of the white population.ConclusionsAlthough existing studies on diffuse economic vulnerability and hate find a weak connection between economic factors and hate, trade layoffs can explain some variation in local hate group activity.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.2136/SSSAJ2018.07.0248", "year": 2019, "title": "Manure Application Decisions Impact Nitrous Oxide and Carbon Dioxide Emissions during NonGrowing Season Thaws", "abstract": " Core Ideas Manure injection increased N2O emissions vs. broadcast and broadcast + plow application. Winter thaws increased N2O and CO2 emissions, particularly in soils injected with manure. The impacts of manure application decisions may extend beyond the growing season to influence N2O and CO2 fluxes during winter thaw events. Climate and agricultural management are strong drivers of greenhouse gas (GHG) emissions, but little is known about potential interactions among these drivers. Climate change will likely increase the frequency of wintertime thaws in northern agricultural systems, which have been shown to induce large pulses of carbon dioxide (CO2) and nitrous oxide (N2O). We tested the hypothesis that different manure application practices would interact with thaw events to produce GHG emission pulses of different sizes. Specifically, we expected manure injection would increase CO2 and N2O emissions relative to other manure application methods by enhancing subsurface microbial substrate availability. We conducted a laboratory incubation study with frozen, intact soil cores from a continuous corn (Zea mays L.) system under three manure application methods: broadcast, broadcast + plow, and injection. Cores were subjected to three temperature treatments over 8 d: frozen (7C), freezethaw (alternating 7 and 5C), and thaw (5C). In the freezethaw and thaw treatments, cumulative N2O emissions were 2 to 20 times greater in injected versus broadcast treatments (6.5 mg N2ON m2 averaged across broadcast treatments); cumulative CO2 emissions were up to two times higher in injected versus broadcast treatments (1017 mg CO2C m2 averaged across broadcast treatments). Our results suggest that the impacts of manure application choices extend beyond the growing season to increase N2O and CO2 emissions during wintertime thaws, potentially interacting with a warming climate to increase GHG emissions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.3390/RS12071221", "year": 2020, "title": "Global trends in evapotranspiration dominated by increases across large cropland regions", "abstract": "Irrigated croplands require large annual water inputs and are critical to global food production. Actual evapotranspiration (AET) is a main index of water use in croplands, and several remote-sensing products have been developed to quantify AET at the global scale. In this study, we estimate global trends in actual AET, potential ET (PET), and precipitation rate (PP) utilizing the MODIS Evapotranspiration product (20012018) within the Google Earth Engine cloud-computing environment. We then introduce a new index based on a combination of AET, PET, and PP estimatesthe evapotranspiration warning index (ETWI)which we use to evaluate the sustainability of observed AET trends. We show that while AET has not considerably changed across global natural lands, it has significantly increased across global croplands (+14% 5%). The average ETWI for global croplands is 0.40 0.25, which is largely driven by an extreme trend in AET, exceeding both PET and PP trends. Furthermore, the trends in water and energy limited areas demonstrate, on a global scale, while AET and PET do not have significant trends in both water and energy limited areas, the increasing trend of PP in energy-limited areas is more than water-limited areas. Averaging cropland ETWI trends at the country level further revealed nonsustainable trends in cropland water consumptions in Thailand, Brazil, and China. These regions were also found to experiencing some of the largest increases in net primary production (NPP) and solar-induced fluorescence (SIF), suggesting that recent increases in food production may be dependent on unsustainable water inputs. Globally, irrigated maize was found to be associated with nonsustainable AET trends relative to other crop types. We present an online open access application designed to enable near real-time monitoring and improve the understanding of global water consumption and availability.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/EN14092652", "year": 2021, "title": "Understanding the Potential of Wind Farm Exploitation in Tropical Island Countries: A Case for Indonesia", "abstract": "Countries worldwide must dramatically reduce their emissions to achieve the goal of limiting temperature increases in line with the Paris Agreement. Involving developing countries in global actions on emission reduction will greatly enhance the effectiveness of global warming mitigation. This study investigated the feasibility of establishing a wind farm at four onshore and three offshore sites in Indonesia. Installing wind turbines with the highest hub height, largest rotor diameter, and lowest cut-in and rated wind speed in an identified area off Wetar Island presented the highest time-based availability and a capacity factor of 46%, as well as the highest power-based availability at 76%. The levelized cost of electricity at 0.082 USD/kWh was comparable to that of power generated from fossil fuels, which ranges from 0.07 to 0.15 USD/kWh in Indonesia. Increasing the feed-in-tariff for wind power from the current 0.08 USD/kWh would provide sufficient incentive for investment. Moving subsidies from fossil fuels toward renewables would facilitate the transition to low-carbon renewables without increasing the financial burden on the country.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1080/10962247.2020.1842822", "year": 2021, "title": "Global emissions of NH3, NOx, and N2O from biomass burning and the impact of climate change", "abstract": "Emissions of ammonia (NH3), oxides of nitrogen (NOx; NO +NO2), and nitrous oxide (N2O) from biomass burning were quantified on a global scale for 2001 to 2015. On average biomass burning emissions at a global scale over the period were as follows: 4.53 0.51 Tg NH3 year1, 14.65 1.60 Tg NOx year1, and 0.97 0.11 Tg N2O year1. Emissions were comparable to other emissions databases. Statistical regression models were developed to project NH3, NOx, and N2O emissions from biomass burning as a function of burn area. Two future climate scenarios (RCP 4.5 and RCP 8.5) were analyzed for 20502055 (mid-century) and 20902095 (end of century). Under the assumptions made in this study, the results indicate emissions of all species are projected to increase under both the RCP 4.5 and RCP 8.5 climate scenarios.Implications: This manuscript quantifies emissions of NH3, NOx, and N2O on a global scale from biomass burning from 20012015 then creates regression models to predict emissions based on climate change. Because reactive nitrogen emissions have such an important role in the global nitrogen cycle, changes in these emissions could lead to a number of health and environmental impacts.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-14-7195-2014", "year": 2014, "title": "Top-down estimates of biomass burning emissions of black carbon in the Western United States", "abstract": "Abstract. We estimate biomass burning and anthropogenic emissions of black carbon (BC) in the western US for MayOctober 2006 by inverting surface BC concentrations from the Interagency Monitoring of PROtected Visual Environment (IMPROVE) network using a global chemical transport model. We first use active fire counts from the Moderate Resolution Imaging Spectroradiometer (MODIS) to improve the spatiotemporal distributions of the biomass burning BC emissions from the Global Fire Emissions Database (GFEDv2). The adjustment primarily shifts emissions from late to middle and early summer (a 33% decrease in SeptemberOctober and a 56% increase in JuneAugust) and leads to appreciable increases in modeled surface BC concentrations in early and middle summer, especially at the 12 and 23 km altitude ranges. We then conduct analytical inversions at both 2 2.5 and 0.5 0.667 (nested over North America) horizontal resolutions. The a posteriori biomass burning BC emissions for JulySeptember are 31.7 Gg at 2 2.5 (an increase by a factor of 4.7) and 19.2 Gg at 0.5 0.667 (an increase by a factor of 2.8). The inversion results are rather sensitive to model resolution. The a posteriori biomass burning emissions at the two model resolutions differ by a factor of ~6 in California and the Southwest and by a factor of 2 in the Pacific Northwest. The corresponding a posteriori anthropogenic BC emissions are 9.1 Gg at 2 2.5 (a decrease of 48%) and 11.2 Gg at 0.5 0.667 (a decrease of 36%). Simulated surface BC concentrations with the a posteriori emissions capture the observed major fire episodes at most sites and the substantial enhancements at the 12 and 23 km altitude ranges. The a posteriori emissions also lead to large bias reductions (by ~30% on average at both model resolutions) in modeled surface BC concentrations and significantly better agreement with observations (increases in Taylor skill scores of 95% at 2 2.5 and 42 % at 0.5 0.667).", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1371/JOURNAL.PONE.0263823", "year": 2022, "title": "Emergence of monopoly\u2013Copper exchange networks during the Late Bronze Age in the western and central Balkans", "abstract": "In this paper we present the first results of an interdisciplinary research project focused on Late Bronze Age metallurgy in the western and central Balkans. The comprehensive chemical and lead isotope analysis, and a strict consideration of archaeological criteria, has provided a deeper insight into supra regional metal exchange networks between the 14th and 9th century BC in this part of Europe. Particularly interesting and surprising are results regarding the provenance of raw materials for copper production, which have a chemical composition and lead isotope ratios that closely correspond to ore deposits in the southern Alps (North Italy). Based on the examination of 57 objects of different functions, chronology and distribution, it becomes apparent that copper from the southern Alps was almost an omnipresent raw material in the territories of the western and central Balkans with only a few finds from North Macedonia to indicate alternative sources. The analyses demonstrate that the reuse of fahlore-based copper is attested for the first time in the regions under study. The remarkable fact that other archaeological parameters do not indicate such an intensive connection between the Balkan area and Northern Italy raises a number of questions. The sustained and long-lasting networks of raw material procurement stand in contrast to the expected cultural interaction between metal producing and metal consuming prehistoric societies. The results of this work also highlight the currently underestimated role of the southern Alps as one of the main copper producing areas in Bronze Age Europe, and demonstrate for the first time that the region of western and central Balkans was one of the major recipients.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ACP-22-9859-2022", "year": 2022, "title": "Vertical structure of biomass burning aerosol transported over the southeast Atlantic Ocean", "abstract": "Abstract. Biomass burning in southwestern Africa produces smoke plumes that\nare transported over the Atlantic Ocean and overlie vast regions of\nstratocumulus clouds. This aerosol layer contributes to direct and indirect\nradiative forcing of the atmosphere in this region particularly during the\nmonths of August, September, and October. There was a multi-year\ninternational campaign to study this aerosol and its interactions with\nclouds. Here, we report on the evolution of aerosol distributions and\nproperties as measured by the airborne high spectral resolution lidar\n(HSRL-2) during the ORACLES (Observations of Aerosols above Clouds and their\nintEractionS) campaign in September 2016. The NASA Langley HSRL-2 instrument\nwas flown on the NASA ER-2 aircraft for several days in September 2016. Data\nwere aggregated at two pairs of 2 2 grid\nboxes to examine the evolution of the vertical profile of aerosol properties\nduring transport over the ocean. Results showed that the structure of the\nprofile of aerosol extinction and microphysical properties is maintained\nover a 1 to 2 d timescale. In the 35 km altitude range, 95 % of\nthe aerosol extinction was contributed by particles in the 0.050.50 m radius size range with the aerosol in this size range having an average\neffective radius of 0.16 m. This indicates that there is essentially\nno scavenging or dry deposition at these altitudes. Moreover, there is very\nlittle day-to-day variation in these properties, such that time sampling as\nhappens in such campaigns may be representative of longer periods such as\nmonthly means. Below 3 km, there is considerable mixing with larger aerosol,\nmost likely continental source near land. Furthermore, these measurements\nindicated that there was often a distinct gap between the bottom of the\naerosol layer and cloud tops at the selected locations as evidenced by a\nlayer of several hundred meters that contained relatively low aerosol\nextinction values above the clouds.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.EIAR.2021.106638", "year": 2021, "title": "Open-source methods for estimating health risks of fine particulate matter from coal-fired power plants: A demonstration from Karachi, Pakistan", "abstract": "Environmental impact assessments (EIAs) effectiveness and accessibility by the public is determined by local environmental enforcement and regulation. Massive energy infrastructure projects like China's Belt and Road initiative (BRI) could accentuate social and economic costs, as regulation is deferred to host countries with varying levels of domestic enforcement. To fill major gaps in the public evaluation of EIA practices and results, our objective here is to present an open-source approach for evaluating localized air pollution health impacts for BRI-financed coal-fired power plants. This analysis focuses on one specific problem, additional attributable mortality from stroke, ischemic heart disease, and chronic obstructive pulmonary disease for adults ages 2584 from fine particulate matter (PM2.5), known to be major risk factor for premature deaths globally. As a concrete example, we examine the case of the Port Qasim power plant located near Karachi, Sindh Province, Pakistan. We present results for two main scenarios: a base case, assuming fully operational pollution control technologies, in particular electrostatic precipitators (ESP); and an alternative case without ESPs. All material and methods for replicating this analysis for the case study and for other projects are available in our institutional open repository. Our approach can be applied immediately to virtually any source location in the world, due to the public and global availability of input data.\nSynopsis\nWe present an open-source approach for evaluating localized health impacts due to fine particulate matter emitted from coal-fired power plants.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RSE.2021.112709", "year": 2021, "title": "Integration of Sentinel optical and radar data for mapping smallholder coffee production systems in Vietnam", "abstract": "Perennial commodity crops, such as coffee, often play a large role globally in agricultural markets and supply chains and locally in livelihoods, poverty reduction, and biodiversity. Yet, the production of spatial information on these crops are often overlooked in favor of annual food crops. Remote sensing detection of coffee faces a particular set of challenges due to persistent cloud cover in the tropical coffee belt, hilly topography in coffee growing regions, diversity of coffee growing systems, and spectral similarity to other tree crops and agricultural land. Looking at the major coffee growing region in Dak Lak, Vietnam, we integrate multi-temporal 10 m optical Sentinel-2 and Sentinel-1 SAR data in order to map three coffee production systems: i) open-canopy sun coffee, ii) intercropped and other shaded coffee and iii) newly planted or young coffee. Leveraging Google Earth Engine (GEE), we compute five sets of features in order to best enhance separability between coffee and other land cover and within coffee production systems. The features include Sentinel-2 dry and wet season composites, Sentinel-1 texture features, Sentinel-1 spatiotemporal metrics, and topographic features. Using a random forest classification algorithm, we produce a 9-class land cover map including our three coffee production classes and a binary coffee/non-coffee map. The binary map has an overall accuracy of 89% and the three coffee production systems have user accuracies of 65, 56, 71% for sun coffee, intercropped coffee and newly planted coffee, respectively. This is a first effort at large-scale distinction of within-crop production styles and has implications across many applications. The binary coffee map can be used as a high-resolution crop mask, whereas the detailed land cover map can inform monitoring of deforestation dynamics, biodiversity, sustainability certification and implementation of climate adaptation strategies. This work offers a scalable approach to integrating optical and radar Sentinel data for production of spatially explicit agricultural information and contributes particularly to tree crop and agroforestry mapping, which often is overlooked in between agricultural and forestry sciences.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1038/S41893-019-0453-5", "year": 2020, "title": "The downstream air pollution impacts of the transition from coal to natural gas in the United States", "abstract": "The recent shift in the United States from coal to natural gas as a primary feedstock for the production of electric power has reduced the intensity of sectoral carbon dioxide emissions, butdue to gaps in monitoringits downstream pollution-related effects have been less well understood. Here, I analyse old units that have been taken offline and new units that have come online to empirically link technology switches to observed aerosol and ozone changes and subsequent impacts on human health, crop yields and regional climate. Between 2005 and 2016 in the continental United States, decommissioning of a coal-fired unit was associated with reduced nearby pollution concentrations and subsequent reductions in mortality and increases in crop yield. In total during this period, the shutdown of coal-fired units saved an estimated 22,563 (5%95% confidence intervals (CI), 1,69743,429) lives and 329 million (169490 million) bushels of corn in their immediate vicinities; these crop estimates increase when pollution transport-related spillovers are included. Changes in primary and secondary aerosol burdens also altered regional atmospheric reflectivity, raising the average top of atmosphere instantaneous radiative forcing by 0.50 W m2. Although there are considerable benefits of decommissioning older coal-fired units, the newer natural gas and coal-fired units that have supplanted them are not entirely benign.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.MARPOLBUL.2016.08.064", "year": 2017, "title": "Preparing for the unprecedented\u2014Towards quantitative oil risk assessment in the Arctic marine areas", "abstract": "The probability of major oil accidents in Arctic seas is increasing alongside with increasing maritime traffic. Hence, there is a growing need to understand the risks posed by oil spills to these unique and sensitive areas. So far these risks have mainly been acknowledged in terms of qualitative descriptions. We introduce a probabilistic framework, based on a general food web approach, to analyze ecological impacts of oil spills. We argue that the food web approach based on key functional groups is more appropriate for providing holistic view of the involved risks than assessments based on single species. We discuss the issues characteristic to the Arctic that need a special attention in risk assessment, and provide examples how to proceed towards quantitative risk estimates. The conceptual model presented in the paper helps to identify the most important risk factors and can be used as a template for more detailed risk assessments.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/F13070988", "year": 2022, "title": "Spatial and Temporal Variations of Predicting Fuel Load in Temperate", "abstract": "The prediction of fuel load areas and species associated with these events reduces the response time to fight forest fires. The objective of this study was to estimate the annual fuel load from 20092013, predict the annual fuel load in the rest of the ecosystem, identify species that contribute most to this load and compare the percentage of area by risk category in the temperate forests of Tamaulipas. Fuel load was estimated with inventory data using three models. Fuel load was predicted with elevation, total annual precipitation, mean annual temperature, and enhanced vegetation index from satellite scenes using partial least squares regression. The highest concentration of fuel load was associated with the oak, oak-pine, pine forest and mountain mesophyll forest ecosystems. The contribution of genera to fuel load was different. Quercus contributed the most variation among clusters, and the contribution among Quercus species was similar. The results highlight the importance of focusing fuel management programs on this type of ecosystem, emphasizing actions in particular Quercus, and the results can also serve as a basis for future research, such as carbon sequestration and forest management programs.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-21-357-2021", "year": 2021, "title": "Insights into the aging of biomass burning aerosol from satellite observations and 3D atmospheric modeling: evolution of the aerosol optical properties in \u2026", "abstract": "Abstract. Long-range transport of biomass burning (BB) aerosol from regions affected by wildfires is known to have a significant impact on the radiative balance and air quality in receptor regions. However, the changes that occur in the optical properties of BB aerosol during long-range transport events are insufficiently understood, limiting the adequacy of representations of the aerosol processes in chemistry transport and climate models. Here we introduce a framework to infer and interpret changes in the optical properties of BB aerosol from satellite observations of multiple BB plumes. Our framework includes (1) a procedure for analysis of available satellite retrievals of the absorption and extinction aerosol optical depths (AAOD and AOD) and single-scattering albedo (SSA) as a function of the BB aerosol photochemical age and (2) a representation of the AAOD and AOD evolution with a chemistry transport model (CTM) involving a simplified volatility basis set (VBS) scheme with a few adjustable parameters. We apply this framework to analyze a large-scale outflow of BB smoke plumes from Siberia toward Europe that occurred in July 2016. We use AAOD and SSA data derived from OMI (Ozone Monitoring Instrument) satellite measurements in the near-UV range along with 550 nm AOD and carbon monoxide (CO) columns retrieved from MODIS (Moderate Resolution Imaging Spectroradiometer) and IASI (Infrared Atmospheric Sounding Interferometer) satellite observations, respectively, to infer changes in the optical properties of Siberian BB aerosol due to its atmospheric aging and to get insights into the processes underlying these changes. Using the satellite data in combination with simulated data from the CHIMERE CTM, we evaluate the enhancement ratios (EnRs) that allow isolating AAOD and AOD changes due to oxidation and gasparticle partitioning processes from those due to other processes, including transport, deposition, and wet scavenging. The behavior of EnRs for AAOD and AOD is then characterized using nonlinear trend analysis. It is found that the EnR for AOD strongly increases (by about a factor of 2) during the first 2030 h of the analyzed evolution period, whereas the EnR for AAOD does not exhibit a statistically significant increase during this period. The increase in AOD is accompanied by a statistically significant enhancement of SSA. Further BB aerosol aging (up to several days) is associated with a strong decrease in EnRs for both AAOD and AOD. Our VBS simulations constrained by the observations are found to be more consistent with satellite observations of strongly aged BB plumes than tracer simulations in which atmospheric transformations of BB organic aerosol were disregarded. The simulation results indicate that the upward trends in EnR for AOD and in SSA are mainly due to atmospheric processing of secondary organic aerosol (SOA), leading to an increase in the mass scattering efficiency of BB aerosol. Evaporation and chemical fragmentation of the SOA species, part of which is assumed to be absorptive (to contain brown carbon), are identified as likely reasons for the subsequent decrease in the EnR for both AAOD and AOD. Hence, our analysis reveals that the long-range transport of smoke plumes from Siberian fires is associated with major changes in BB aerosol optical properties and chemical composition. Overall, this study demonstrates the feasibility of using available satellite observations for evaluating and improving representations in atmospheric models of the BB aerosol aging processes in different regions of the world at much larger temporal scales than those typically addressed in aerosol chamber experiments.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1080/1540496X.2018.1541134", "year": 2019, "title": "Stranded coal power assets in China: a case study of Jilin Province", "abstract": "This article conducts the first provincial case study on the effect of environment-related risks on coal-fired power plants in Jilin, China, which creates stranded assets. Using power capacity expansion model and project evaluation model, the article first quantifies the rational coal power capacity during 20162020. Then, we calculate the value of stranded assets. The estimated scale of excess coal power capacity by 2020 ranges from 8,190 MW to 18,480 MW. The total value of stranded assets will decline over time under the different scenarios. Finally, policy implications for policymakers on power market reforms are proposed.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JCLEPRO.2019.07.073", "year": 2019, "title": "Sustainable alternatives to carbon intensive paddy field burning in India: A framework for cleaner production in agriculture, energy, and construction industries", "abstract": "Field burning of rice straw as a method of disposal by farmers is a major concern as the smoke and harmful emissions from it causes dangerous levels of pollution. Seven out of ten cities with the poorest air quality in the world are in India, and paddy field burning has been cited as one of the main reasons. Hazardous emissions from paddy field burning is combined with greenhouse gas emissions from coal fired power plants and cement manufacturing units, causing severe respiratory illnesses and other fatal health issues. The recent literature indicates an increased interest in rice straw valorisation, possibly in response to the increasing concerns over paddy field burning. However, a systematic study that compiles and compares various rice straw valorisation routes is lacking in the existing literature. This paper provides a comprehensive review of literature on various alternative uses of rice straw in energy and construction industries. Effective use of rice straw as a biomass fuel in energy sector not only reduces the field burning, but also decreases the dependency on non-renewable fossil fuels. Moreover, the proposed utilisation of secondary by-products from rice straw-based energy production in the construction industry can help to attain the goals of resource cascading. The availability of rice straw in major rice producing states of India and the feasibility of establishing rice straw-based power plants are also examined in this study. The potential reduction of harmful emissions from such resource recycling has been determined as per the guidelines issued by the intergovernmental panel on climate change. From the review of literature and the findings of the present study, a sustainable framework has been developed with well-defined cleaner production pathways to create a seamless material flow chain between the agricultural, energy, and construction sectors.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/EN15103669", "year": 2022, "title": "Correlation between the Production of Electricity by Offshore Wind Farms and the Demand for Electricity in Polish Conditions", "abstract": "Energy transition forcing a change in the structure of the electricity generation system is a particularly difficult task in countries such as Poland, where the dominant source of energy is fossil fuels. Due to the nature of renewable sources (stochastic and seasonally variable), it is necessary to study their impact on the power system. Much research was conducted on this subject. They consider modelling power systems in terms of dealing with an increasing amount of renewable energy sources, stabilization of electricity generation or environmental aspects. This article examines one of the key sources of future power systemsoffshore wind turbines (OWT). The influence of offshore wind sources on the power system in the fields of stability of generation, methods of regulatory strategies, and economics were examined. One of the aspects that are less considered is the correlation of energy production in OWT with energy demand and with generation in other renewable energy sources, especially in the region of the southern Baltic Sea and the distribution of energy demand in countries such as Poland. The key aspect of the research is to fill this gap. The obtained results indicate that the average monthly power generation in OWT is strongly positively correlated with the demand, and the hourly average is positively correlated moderately. Correlation between generation in OWT and photovoltaic sources is very high negative, and between onshore and offshore wind turbines is highly positive. The study indicates that the OWT has a significant potential for the development and replacement of conventional sources, due to the very high capacity and a positive correlation with demand. Moreover, future offshore wind farms can cooperate with photovoltaic sources as these sources complement each other. On the other hand, a significant saturation of the system with offshore and onshore wind sources may pose a threat to the power system due to their positive correlation.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RSE.2016.07.023", "year": 2016, "title": "Forest aboveground biomass mapping and estimation across multiple spatial scales using model-based inference", "abstract": "Remotely sensed data have been widely used in recent years for mapping and estimating biomass. However, the characterization of the uncertainty of mapped or estimated biomass in previous studies was either based on ad-hoc approaches (e.g., using model fitting statistics such root mean square errors derived from purposive samples) or mostly limited to the analysis of mean biomass for the whole study area. This study proposed a novel uncertainty analysis method that can characterize biomass uncertainty across multiple spatial scales and multiple spatial resolutions. The uncertainty analysis method built on model-based inference and can propagate errors from trees to field plots, individual pixels, and small areas or large regions that consist of multiple pixels (up to all pixels within a study area). We developed and tested this method over northern Minnesota forest areas of approximately 69,508km2 via a unique combination of several datasets for biomass mapping and estimation: wall-to-wall airborne lidar data, national forest inventory (NFI) plots, and destructive measurements of tree aboveground biomass (AGB). We found that the pixel-level AGB prediction error is dominated by lidar-based AGB model residual errors when the spatial resolution is near 380m or finer and by model parameter estimate errors when the spatial resolution is coarser. We also found that the relative error of AGB predicted from lidar can be reduced to approximately 11% (or mean 5.1Mg/ha; max 43.6Mg/ha) at one-hectare scale (or at 100m spatial resolution) over our study area. Because our uncertainty analysis method uses model-based inference and does not require probability samples of field plots, our methodology has potential applications worldwide, especially over tropics and developing countries where NFI systems are not well-established.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS13142713", "year": 2021, "title": "Mapping Threats of Spring Frost Damage to Tea Plants Using Satellite-Based Minimum Temperature Estimation in China", "abstract": "Spring frost damage (SFD), defined as the disaster during the period of newly formed tea buds in spring caused by lower temperature and frost damage, is a particular challenge for tea plants (Camellia sinensis), whose capacity to adapt to extreme weather and climate impacts is limited. In this paper, the region of the Middle and Lower Reaches of the Yangtze River (MLRYR) in China was selected as the major tea plantation study area, and the study period was focused on the concentrated occurrence of SFD, i.e., from March to April. By employing the standard lapse rate of air temperature with elevation, a minimum temperature (Tmin) estimation model that had been previously established was used based on reconstructed MYD11A1 nighttime LST values for 3 3 pixel windows and digital elevation model data. Combined with satellite-based Tmin estimates and ground-based Tmin observations, the spatiotemporal characteristics of SFD for tea plants were systematically analyzed from 2003 to 2020 in the MLRYR. The SFD risks at three scales (temporal, spatial, and terrain) were then evaluated for tea plants over the MLRYR. The results show that both SFD days at the annual scale and SFD areas at the daily scale exhibited a decreasing trend at a rate of 2.7 days/decade and 2.45 104 ha/day, respectively (significant rates at the 0.05 and 0.01 levels, respectively). The period with the highest SFD risk appeared mainly in the first twenty days of March. However, more attention should be given to the mid-to-late April time period due to the occurrence of late SFD from time to time. Spatially, areas with relatively higher SFD days and SFD risks were predominantly concentrated in the higher altitude areas of northwestern parts of MLRYR for both multi-year averages and individual years. Fortunately, in regions with a higher risk of SFD, the distribution of tea plants was relatively scattered and the area was small. These findings will provide helpful guidance for all kinds of people, including government agencies, agricultural insurance agencies, and tea farmers, in order that reasonable and effective strategies to reduce losses caused by spring frost damage to tea plants may be recommended and implemented.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.ASR.2021.09.024", "year": 2021, "title": "Re-entry prediction and demisability analysis for the atmospheric disposal of geosynchronous satellites", "abstract": "The paper presents a re-entry analysis of Geosynchronous Orbit (GSO) satellites on disposal trajectories that enhance the effects of the Earth oblateness and lunisolar perturbations. These types of trajectories can lead to a natural re-entry of the spacecraft within 20 years. An analysis was performed to characterise the entry conditions for these satellites and the risk they can pose for people on the ground if disposal via re-entry is used. The paper first proposes a methodology to interface the long-term propagation used to study the evolution of the disposal trajectories and the destructive re-entry simulations used to assess the spacecraft casualty risk. This is achieved by revisiting the concept of overshoot boundary. The paper also presents the demisability and casualty risk analysis for a representative spacecraft configuration, showing that the casualty risk is greater than the 104 threshold and that further actions should be taken to improve the compliance of these satellites in case disposal via re-entry is used.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-20-2387-2020", "year": 2020, "title": "Long-range aerosol transport and impacts on size-resolved aerosol composition in Metro Manila, Philippines", "abstract": "Abstract. This study analyzes long-range transport of aerosol and aerosol chemical characteristics based on instances of high- and low-aerosol-loading events determined via ground-based size-resolved aerosol measurements collected at the Manila Observatory in Metro Manila, Philippines, from July to October 2018. Multiple data sources, including models, remote sensing, and in situ measurements, are used to analyze the impacts of long-range aerosol transport on Metro Manila and the conditions at the local and synoptic scales facilitating this transport. Through the use of case studies, evidence of long-range transport of biomass burning aerosol and continental emissions is identified in Metro Manila. Long-range transport of biomass burning aerosol from the Maritime Continent, bolstered by southwesterly flow and permitted by low rainfall, was identified through model results and the presence of biomass burning tracers (e.g., K, Rb) in the ground-based measurements. The impacts of emissions transported from continental East Asia on the aerosol characteristics in Metro Manila are also identified; for one of the events analyzed, this transport was facilitated by the nearby passage of a typhoon. Changes in the aerosol size distributions, water-soluble chemical composition, and contributions of various organic aerosol species to the total water-soluble organic aerosol were examined for the different cases. The events impacted by biomass burning transport had the overall highest concentration of water-soluble organic acids, while the events impacted by long-range transport from continental East Asia showed high percent contributions from shorter-chain dicarboxylic acids (i.e., oxalate) that are often representative of photochemical and aqueous processing in the atmosphere. The low-aerosol-loading event was subject to a larger precipitation accumulation than the high-aerosol events, indicative of wet scavenging as an aerosol sink in the study region. This low-aerosol event was characterized by a larger relative contribution from supermicrometer aerosols and had a higher percent contribution from longer-chain dicarboxylic acids (i.e., maleate) to the water-soluble organic aerosol fraction, indicating the importance of both primary aerosol emissions and local emissions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1186/S13021-016-0055-8", "year": 2016, "title": "Mapping and estimating the total living biomass and carbon in low-biomass woodlands using Landsat 8 CDR data", "abstract": "A functional forest carbon measuring, reporting and verification (MRV) system to support climate change mitigation policies, such as REDD+, requires estimates of forest biomass carbon, as an input to estimate emissions. A combination of field inventory and remote sensing is expected to provide those data. By linking Landsat 8 and forest inventory data, we (1) developed linear mixed effects models for total living biomass (TLB) estimation as a function of spectral variables, (2) developed a 30 m resolution map of the total living carbon (TLC), and (3) estimated the total TLB stock of the study area. Inventory data consisted of tree measurements from 500 plots in 63 clusters in a 15,700 km2 study area, in miombo woodlands of Tanzania. The Landsat 8 data comprised two climate data record images covering the inventory area.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.2172/1363940", "year": 2017, "title": "Carbon cycle dynamics within Oregon's urban-suburban-forested-agricultural landscapes", "abstract": "Our overarching goal was to develop and utilize an observation-based analysis framework to assess interactions between climate and mosaics of land use, land cover and urbanization on regional carbon, water, and energy dynamics, and potential changes associated with land management and climate. Carbon, water and energy cycling was quantified for the range of current and potential land uses under present and future climates. The study region of Oregon has a strong climatic gradient from the coastal mesic forests (2500mm ppt) to the Willamette Valley, Cascade Mountains, and the Northern Great Basin semi-arid cold desert to the east (300 mm). The study was focused on the effects of (1) conversion of semi-arid sagebrush and Willamette Valley agricultural crops to bioenergy production; (2) afforestation of idle land and rangelands deemed suitable for forests or poplar crops under future climate conditions. We found that net ecosystem production (NEP), the net of ecosystem photosynthesis and respiration, was 10 times higher in the high biomass forests of the Coast Range compared with drier regions like sagebrush in the Northern Great Basin, which was nearly zero (Schmidt et al. 2016). The state total NEP averaged about 30 teragrams carbon (Tg C) per year for the years 2012 to 2014 using our model framework that we developed for predictions of current and future NEP, and compared well with our detailed inventory estimates (28 Tg C annual average for 2011-2015 for forests only; Law et al. 2017). Running our model framework until the year 2050, we found that climate alone only increased NEP by less than 1 Tg C per decade (~3%) using the current trajectory of carbon dioxide emissions, however, changes are expected to be more rapid in subsequent years. We evaluated the possibility of land use change from grass seed crops to poplar for bioenergy, which slightly increased NEP by 2050. The most important variable for carbon sequestration estimates (net carbon sources and sinks) is net ecosystem carbon balance (NECB), which accounts for NEP and losses associated with harvest removals and wildfire emissions. Here, we focus on forests because they have the largest effect on carbon sequestration. We found that NECB in Oregon averaged 18.8 Tg C per year in 2011-2015, offsetting fossil fuel emissions (16 Tg C per year). Annual fire emissions reducing NECB by about 5% (0.97 Tg C per year) in the state. The mesic Coast Range and West Cascades ecoregions that make up the western third of Oregon account for 60% of the forest NECB. This analysis illustrates that annual emissions from forests disturbances are low relative to annual fossil fuel emissions for the same area (Law et al. 2017, Hudiburg et al. in review).", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1017/S0030605318000388", "year": 2020, "title": "The burning question: does fire affect habitat selection and forage", "abstract": "Abstract\r\n \r\n The conservation of threatened species requires information on how management activities influence habitat quality. The Critically Endangered black rhinoceros\r\n Diceros bicornis\r\n is restricted to savannahs representing c. 5% of its historical range. Fire is used extensively in savannahs but little is known about how rhinos respond to burning. Our aim was to understand rhino responses to fire by studying habitat selection and foraging at multiple scales. We used resource selection functions and locations of 31 rhinos during 20142016 to study rhino habitat use in Serengeti National Park, Tanzania. Rhino selectivity was quantified by comparing forage consumption to plant species availability in randomly sampled vegetation plots; rhino diets were subsequently verified through DNA metabarcoding analysis of faecal samples. Rhino habitat use was a unimodal function of fire history, with highly occupied sites having fire frequencies of < 0.6 fires/year and maximum occupancy occurring at a fire frequency of 0.1 fires/year. Foraging stations had characteristic plant communities, with 17 species associated with rhino foraging. Rhinos were associated with, and disproportionately consumed, woody plants, forbs and legumes, all of which decreased in abundance with increasing fire frequency. In contrast to common management practices, multiple lines of evidence suggest that the current fire regime in the Serengeti negatively influences rhino habitat use and foraging and that frequent fire limits access of rhinos to preferred forage. We outline a conceptual model to guide managers and conservationists in the use of fire under variable habitat conditions.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-22-4075-2022", "year": 2022, "title": "Impact of biomass burning and stratospheric intrusions in the remote South Pacific Ocean troposphere", "abstract": "Abstract. The ozone mixing ratio spatiotemporal variability in the pristine South Pacific Ocean is studied, for the first time, using 21-year-long ozone (O3) records from the entire southern tropical and subtropical Pacific between 1994 and 2014. The analysis considered regional O3 vertical observations from ozonesondes, surface carbon monoxide (CO) observations from flasks, and three-dimensional chemistry-transport model simulations of the global troposphere. Two 21-year-long numerical simulations, with and without biomass burning emissions, were performed to disentangle the importance of biomass burning relative to stratospheric intrusions for ambient ozone levels in the region. Tagged tracers of O3 from the stratosphere and CO from various biomass burning regions have been used to track the impact of these different regions on the southern tropical Pacific O3 and CO levels. Patterns have been analyzed based on atmospheric dynamics variability. Considering the interannual variability in the observations, the model can capture the observed ozone gradients in the troposphere with a positive bias of 7.5 % in the upper troposphere/lower stratosphere (UTLS) as well as near the surface. Remarkably, even the most pristine region of the global ocean is affected by distant biomass burning emissions by convective outflow through the mid and high troposphere and subsequent subsidence over the pristine oceanic region. Therefore, the biomass burning contribution to tropospheric CO levels maximizes in the UTLS. The Southeast Asian open fires have been identified as the major contributing source to CO from biomass burning in the tropical South Pacific, contributing on average for the study period about 8.5 and 13 ppbv of CO at Rapa Nui and Samoa, respectively, at an altitude of around 12 km during the burning season in the spring of the Southern Hemisphere. South America is the second-most important biomass burning source region that influences the study area. Its impact maximizes in the lower troposphere (6.5 ppbv for Rapa Nui and 3.8 ppbv for Samoa). All biomass burning sources contribute about 1523 ppbv of CO at Rapa Nui and Samoa and account for about 25 % of the total CO in the entire troposphere of the tropical and subtropical South Pacific. This impact is also seen on tropospheric O3, to which biomass burning O3 precursor emissions contribute only a few ppbv during the burning period, while the stratospheretroposphere exchange is the most important source of O3 for the mid troposphere of the South Pacific Ocean, contributing about 1520 ppbv in the subtropics.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/SU14063675", "year": 2022, "title": "Quantifying the WaterCarbonSulfur Nexus for Coal Power Plants in China", "abstract": "China has implemented strict policies for the installation of desulfurization facilities in coal power plants in order to mitigate their negative environmental and human health impacts. However, it is rarely acknowledged that desulfurization processes lead to increased water consumption and carbon emissions from the coal power sector. By using a bottom-up approach, we quantified that the desulfurization facilities in all of Chinas coal power plants together avoided emissions of 29.52 Mt of SO2 in 2014, with expenses of 550.26 million m3 of increased water consumption, and 53.28 Mt of additional CO2 emissions. Such conflicts were especially pronounced in the North China Grid, where 9.77 Mt of SO2 emission reductions were realized at expenses of 132.15 million m3 of water consumption, and 14.25 Mt of CO2 emissions. The provinces in the North China Grid were already facing extreme water scarcity. Furthermore, while more than 90% of Chinas coal power plants have installed desulfurization facilities, the application of full desulfurization would further reduce the greatest amount of SO2 emissions with the smallest amounts of additional water consumption and carbon emissions in the Northwest Grid. Replacing all wet desulfurization facilities with dry ones saves 498.38 million m3 of water consumption in total, and reduces 26.65 Mt of CO2 emissions; however, this is at an expense of 14.33 Mt of SO2 emissions. These conflicts are most pronounced in Shanxi Province in the North Grid, and in Guangdong Province in the South Grid.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1111/GCBB.12912", "year": 2022, "title": "Assessing the potential for unaccounted emissions from bioenergy and the implications for forests: The United States and global", "abstract": "Development of the bioenergy sector is being actively pursued in many countries as a means to reduce climate change and fulfill international climate agreements such as the Paris Agreement. Although biomass for energy production (especially wood pellets) can replace carbon\u2011intensive fossil fuels, its net greenhouse gas impact varies, and the production of wood pellets can also lead to intensification in forest harvests and reduction of forest carbon stocks. Additionally, under specific conditions, emissions associated with imported biomass feedstocks may be omitted from national accounts, due to incompatibilities in accounting approaches. We assessed the risks and potential scale of emissions omitted from accounts (EOA) among key trading regions, focusing on the demand for wood pellets under different levels of climate mitigation targets. Our results suggest that the global production of wood pellets would grow from 38.9 to 120 Mton/year between 2019 and 2050 in a scenario that limits global mean temperature increase to 1.5\u00b0C above pre\u2011industrial levels. A large portion of this occurs in North America (36.8 Mton/year by 2050), Europe (47.6 Mton/year by 2050), and Asia (23.3 Mton/year by 2050). We estimate that in a 1.5\u00b0C scenario, global EOA associated with international trade of wood pellets has the potential to reach 23.81 MtCO2eq/year by 2030 and 69.52 MtCO2eq/year in 2050. Emissions resulting from European biomass energy production, based on wood pellet imports from the United States, may reach 11.68 MtCO2eq/year by 2030 and 33.57 MtCO2eq/year in 2050. The production of wood pellet feedstocks may also present a substantial carbon price arbitrage opportunity for bioenergy producers through a conjunction of two distinct GHG accounting rules. If this opportunity is realized, it could accelerate the growth of the bioenergy industry to levels that harm forests' function as a carbon sink and omit actual emissions in national and global accounting frameworks.We quantify and map regional flows of wood pellets under a range of mitigation scenarios. We find that demand for bioenergy will vary widely under different climate mitigation scenarios, with more ambitious pathways driving higher global demand, more intense forest harvest, and a potential reduction in forest carbon sequestration in the U.S. Southeast, a key supply region. Additionally, differences in carbon accounting among countries could encourage arbitrage by bioenergy producers, with the potential to inflate the industry to levels that diminish the forest carbon sink and lead to underestimates of global emissions.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/AMT-15-4271-2022", "year": 2022, "title": "A quadcopter unmanned aerial system (UAS)-based methodology for measuring biomass burning emission factors", "abstract": "Abstract. Biomass burning (BB) emits large quantities of greenhouse gases (GHG) and aerosols that impact the climate and adversely affect human health. Although much research has focused on quantifying BB emissions on regional to global scales, field measurements of BB emission factors (EFs) are sparse, clustered and indicate high spatio-temporal variability. EFs are generally calculated from ground or aeroplane measurements with respective potential biases towards smouldering or flaming combustion products. Unmanned aerial systems (UAS) have the potential to measure BB EFs in fresh smoke, targeting different parts of the plume at relatively low cost. We propose a light-weight UAS-based method to measure EFs for carbon monoxide (CO), carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) as well as PM2.5 (TSI Sidepak AM520) and equivalent black carbon (eBC, microAeth AE51) using a combination of a sampling system with Tedlar bags which can be analysed on the ground and with airborne aerosol sensors. In this study, we address the main challenges associated with this approach: (1) the degree to which a limited number of samples is representative for the integral smoke plume and (2) the performance of the lightweight aerosol sensors. While aerosol measurements can be made continuously in a UAS set-up thanks to the lightweight analysers, the representativeness of our Tedlar bag filling approach was tested during prescribed burning experiments in the Kruger National Park, South Africa. We compared fire-averaged EFs from UAS-sampled bags for savanna fires with integrated EFs from co-located mast measurements. Both measurements matched reasonably well with linear R2 ranging from 0.81 to 0.94. Both aerosol sensors are not factory calibrated for BB particles and therefore require additional calibration. In a series of smoke chamber experiments, we compared the lightweight sensors with high-fidelity equipment to empirically determine specific calibration factors (CF) for measuring BB particles. For the PM mass concentration from a TSI Sidepak AM520, we found an optimal CF of 0.27, using a scanning mobility particle sizer and gravimetric reference methods, although the CF varied for different vegetation fuel types. Measurements of eBC from the Aethlabs AE51 aethalometer agreed well with the multi-wavelength aethalometer (AE33) (linear R2 of 0.95 at =880 nm) and the wavelength corrected multi-angle absorption photometer (MAAP, R2 of 0.83 measuring at =637 nm). However, the high variability in observed BB mass absorption cross-section (MAC) values (5.25.1 m2 g1) suggested re-calibration may be required for individual fires. Overall, our results indicate that the proposed UAS set-up can obtain representative BB EFs for individual savanna fires if proper correction factors are applied and operating limitations are well understood.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41598-019-52799-X", "year": 2019, "title": "Connecting crop productivity, residue fires, and air quality over northern India", "abstract": "Northwestern India is known as the breadbasket of the country producing two-thirds of food grains, with wheat and rice as the principal crops grown under the crop rotation system. Agricultural data from India indicates a 25% increase in the post-monsoon rice crop production in Punjab during 20022016. NASAs A-train satellite sensors detect a consistent increase in the vegetation index (net 21%) and post-harvest agricultural fire activity (net ~60%) leading to nearly 43% increase in aerosol loading over the populous Indo-Gangetic Plain in northern India. The ground-level particulate matter (PM2.5) downwind over New Delhi shows a concurrent uptrend of net 60%. The effectiveness of a robust satellite-based relationship between vegetation indexa proxy for crop amounts, and post-harvest firesa precursor of extreme air pollution events, has been further demonstrated in predicting the seasonal agricultural burning. An efficient crop residue management system is critically needed towards eliminating open field burning to mitigate episodic hazardous air quality over northern India.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-17-5205-2017", "year": 2017, "title": "Direct radiative effect of carbonaceous aerosols from crop residue burning during the summer harvest season in East China", "abstract": "Abstract. East China experiences extensive crop residue burnings in fields during harvest season. The direct radiative effect (DRE) of carbonaceous aerosols from crop residue burning in June 2013 in East China was investigated using the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). Absorption of organic aerosol (OA) in the presence of brown carbon was considered using the parameterization of Saleh et al. (2014), in which the imaginary part of the OA refractive index is a function of wavelength and the ratio of black carbon (BC) and OA. The carbonaceous emissions from crop fires were estimated using the Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power (FRP) product with a localized crop-burning-sourced BC-to-organic carbon (OC) ratio emission ratio of 0.27. Evaluation of the model results with in situ measurements of particulate matter with aerodynamic diameter less than 2.5 m (PM2. 5) chemical composition, MODIS aerosol optical depth (AOD) detections and meteorological observations showed that this model was able to reproduce the magnitude, spatial variation and optical characteristics of carbonaceous aerosol pollution. The observed BC and OC peak concentrations at the site in Suixi, Anhui province, during the 2013 wheat burning season reached 55.3 g m3 and 157.9 g m3. WRF-Chem simulations reproduced these trends with a correlation coefficient of 0.74, estimating that crop residue burning contributed 86 and 90 % of peak BC and OC, respectively. The simulated hourly DRE from crop residue burning at the top of atmosphere (TOA) reached a maximum of +22.66 W m2 at the Suixi site. On average, the simulations showed that the crop residue burning introduced a net positive DRE of +0.14 W m2 at TOA throughout East China, with BC from this source as the main heating contributor (+0.79 W m2). The OA DRE from crop burning (0.22 W m2) was a combined effect of the positive DRE of absorption (+0.21 W m2) and a stronger negative DRE of scattering (0.43 W m2). Sensitivity tests showed that the DRE of OA absorption strongly depended on the imaginary part of the OA refractive index, the BC-to-OA emission ratio from crop residue burning and the assumed mixing state of the aerosol, whereby the volume mixing treatment resulted in a higher positive DRE compared to the coreshell treatment. The BC mixing state and associated absorption enhancement during BC aging processes will be investigated in detail in future research.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-20-15635-2020", "year": 2020, "title": "Measurements to determine the mixing state of black carbon emitted from the 2017\u20132018 California wildfires and urban Los Angeles", "abstract": "Abstract. The effects of atmospheric black carbon (BC) on climate and public health have been well established, but large uncertainties remain regarding the extent of the impacts of BC at different temporal and spatial scales. These uncertainties are largely due to the heterogeneous nature of BC in terms of its spatiotemporal distribution, mixing state, and coating composition. Here, we seek to further understand the size and mixing state of BC emitted from various sources and aged over different timescales using field measurements in the Los Angeles region. We measured refractory black carbon (rBC) with a single-particle soot photometer (SP2) on Catalina Island, California (70 km southwest of downtown Los Angeles) during three different time periods. During the first campaign (September 2017), westerly winds were dominant and measured air masses were representative of well-aged background over the Pacific Ocean. In the second and third campaigns (December 2017 and November 2018, respectively), atypical Santa Ana wind conditions allowed us to measure biomass burning rBC (BCbb) from air masses dominated by large biomass burning events in California and fossil fuel rBC (BCff) from the Los Angeles Basin. We observed that the emissions source type heavily influenced both the size distribution of the rBC cores and the rBC mixing state. BCbb had thicker coatings and larger core diameters than BBff. We observed a mean coating thickness (CTBC) of 4070 nm and a count mean diameter (CMD) of 120 nm for BCbb. For BCff, we observed a CTBC of 515 nm and a CMD of 100 nm. Our observations also provided evidence that aging led to an increased CTBC for both BCbb and BCff. Aging timescales < 1 d were insufficient to thickly coat freshly emitted BCff. However, CTBC for aged BCff within aged background plumes was 35 nm thicker than CTBC for fresh BCff. Likewise, we found that CTBC for aged BCbb was 18 nm thicker than CTBC for fresh BCbb. The results presented in this study highlight the wide variability in the BC mixing state and provide additional evidence that the emissions source type and aging influence rBC microphysical properties.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ENERGY.2022.123261", "year": 2022, "title": "Risk-Calibrated conventional-renewable generation mix using master-slave", "abstract": "This paper proposes a master-slave approach to quantify, combine and balance energy-risk and cost-risk involved in a generation portfolio with renewable and fuel-based technologies. Subjective preferences of the investor on risk, cost and emission are traded-off using pareto-optimization and quantified using multi-criteria decision-making techniques. Temporal variations in renewable energy production led to 'energy-risk' (kWh), characterized by energy-return-risk Efficient Frontier (EF). The uncertainty in the energy production cost of the fuel-based sources (FBS) results in 'cost-risk' ($/kWh), represented by cost-risk EF. These efficient frontiers are combined using the concepts of Sharpe ratio and tangency portfolio. The master portfolio (MP) gives a percentage share for the total renewable and total conventional generation. The slave portfolio (SP) assigns internal weights within the renewable (solar and wind) and within the fuel-based (coal, natural gas, and oil) generations. The best solution is selected from the pareto-front by calibrating the investor preferences using Analytic Hierarchy Process (AHP) and then verified using Elimination and Choice Translating Reality (ELECTRE). It is understood that a completely customizable multi-criteria portfolio selection can be achieved by incorporating subjective views of the investors, eliminating one-sided energy portfolios.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2020.10.018", "year": 2020, "title": "Impact of decomposition and kriging models on the solar irradiance downscaling accuracy in regions with complex topography", "abstract": "Many small island states are planning to invest heavily in solar photovoltaics in an attempt to curb their overreliance on fossil fuels for electricity generation. In order to efficiently exploit the abundant solar energy resource, these islands need reliable solar irradiance data. However, the orographic effects arising from their volcanic origins often result in strong variability and uncertainty in the solar resource. In this context, satellite-based models present an effective alternative to ground-based measurements. Different downscaling approaches have been applied that compensate for the large spatial resolution of satellite images and the terrain-related effects that they disregard. Nevertheless, the accuracy of these methods is influenced by the solar radiation decomposition model used. Moreover, the variogram model used in the kriging process to characterize the spatial dependence of the solar radiation has a significant effect on the results. In this study, we compare the performances of seven radiation decomposition models for the anisotropy analysis and seven variogram models for the spatial interpolation of the solar irradiance. A dense network of ground measurements at 43 stations is used to evaluate the accuracy of the different models. Results reveal that the Yao radiation model coupled with the Matern variogram provide the best results.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.3390/EN15228612", "year": 2022, "title": "Comparative Reliability Assessment of Hybrid Si/SiC and Conventional Si", "abstract": "Energy harnessing from renewable energy sources has become more flexible with power electronic technologies. Recent advancements in power electronic technologies achieve converter efficiency higher than 98%. Today, reliable power electronic devices are needed to design a PV-based energy converter (inverter) to reduce the risk of failure and maintenance costs during operation. Wide-bandgap SiC devices are becoming more common in power electronic converters. These devices are designed to reduce switching loss and improve the efficiency of the system. Nevertheless, the cost of SiC devices is a major concern. Hence, to improve the reliability of the PV inverter while considering the economic aspects, this paper develops a highly reliable PV inverter with a hybrid Si/SiC power module that consists of a Si-IGBT with a SiC anti-parallel diode. A test case of a 3 kW PV inverter is considered for reliability analysis. The loading of the PV inverter is done under uncertain environmental conditions by considering the yearly Mission Profile (MP) data related to Ambient Temperature (AT) and Solar Irradiance (SI) at the India and Denmark locations. The effectiveness of the proposed hybrid Si/SiC power module is tested by comparing it with a conventional IGBT power module. The results showcase the marked improvement in PV inverter reliability with the proposed hybrid power module.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S00190-021-01483-Y", "year": 2021, "title": "Influence of temporal resolution on the performance of global ionospheric maps", "abstract": "Global ionosphere maps (GIM) computed from dual-frequency GNSS measurements have been widely used for monitoring ionosphere as well as providing ionospheric corrections in Space Geodesy since 1998. This work focuses on a comprehensive study of the influence of time resolution on GIM performance. One and a half solar cycle of the IGS GIM with higher time resolution and accuracy (the UPC-IonSAT Quarter-of-an-hour time resolution Rapid GIM, AKA uqrg) has been taken as baseline to downsample them to all possible sub-daily temporal resolutions. The performance of the resulting GIMs has been assessed by directly comparing with external vertical total electron content (VTEC) measurements from Jason altimeters over oceanic regions. In order to perform a complete assessment and analysis of involved GIMs, the influence of geographical position and solar and geomagnetic activities was also taken into account during more than one solar cycle. In addition, to have a clear view at the smaller time resolutions, a more accurate assessment, the dSTEC test based on external GNSS measurements not used in the GIM generation was also done during two solstice and two equinox days in 2015 over continental regions. The assessment shows that discrepancy among GIMs with different time resolutions becomes more apparent at low latitudes and also at high solar-geomagnetic activity. The results also suggest that the accuracy for GIMs with time resolution smaller or equal to 60 min is consistent during the period from 2002 to 2019 and is more accurate than other GIMs with lower temporal resolution. Accordingly, high time resolution (including 15, 30, 45 and 60 min) is recommended for the application of GIMs with the highest accuracy.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SOLENER.2021.03.029", "year": 2021, "title": "Estimating surface solar irradiance from geostationary Himawari-8 over Australia: A physics-based method with calibration", "abstract": "Surface Solar Irradiance (SSI) is required for solar energy planning and adoption, and is a fundamental parameter in modelling weather, climate, ecosystem and agricultural activities. Herein a time series based radiative transfer model was developed to simultaneously retrieve properties of clouds, aerosols and surface albedo, which were in turn used to calculate the components of SSI: i.e., global, direct and diffuse irradiance. The calculated results were calibrated across the Australian continent against in-situ measurements to account for minor factors (e.g., water vapor) not considered by the physics-based method. Detailed validation of the SSI components was performed against three years of in-situ measurements at 11 sites across Australia, at a range of time scales (i.e., instantaneous, hourly, daily and monthly) and under both all-sky and cloudy-sky conditions. The main advantage of the present method is the reliable separation of the direct and diffuse components with consistently low biases (~4 W/m2) at all four time scales, while still maintaining relatively low RMSE (root-mean-square-error) and MAE (mean-absolute-error). Once calibration has been performed the model does not require any ancillary data when implemented operationally: that is the model only requires geostationary satellite data. This model may be implemented across the globe using widely available next generation geostationary satellite data with a handful of ground-data for calibration.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.3847/1538-3881/ABBC15", "year": 2020, "title": "Earth as an Exoplanet. I. Time Variable Thermal Emission Using Spatially Resolved Moderate Imaging Spectroradiometer Data", "abstract": "Among the more than 4000 exoplanets known today, some terrestrial planets have been detected in the so-called habitable zone of their host stars and their number is expected to increase in the near future, energizing a drive to understand and interpret the eagerly awaited wealth of data to identify signs of life beyond our solar system. So far, Earth remains the best and only example of a habitable (and inhabited) world. Although, it seems extremely unlikely that any other exoplanets will be true Earth twins, it is important to explore and understand the full range of spectral signatures and variability of Earth in order to inform the design of future instruments and missions, and understand their diagnostic power as well as potential limitations. In this work we use Earth observation data collected by the MODIS instrument aboard the Aqua satellite. The complete data set comprises 15 years of thermal emission observations in the 3.66-14.40 \u03bcm range for five different locations on Earth (Amazon Rainforest, Antarctica, Arctic, Indian Ocean, and the Sahara Desert). We then determine flux levels and variations as a function of wavelength and surface type (i.e., climate zone and surface thermal properties) and investigate whether periodic signals indicating Earth&'s tilted rotation axis can be detected. Our findings suggest that (1) viewing geometry plays an important role when thermal emission data is analyzed as Earth&'s spectrum varies by a factor of three and more depending on the dominant surface type underneath; (2) typically strong absorption bands from CO2 (15 \u03bcm) and O3 (9.65 \u03bcm) are significantly less pronounced and partially absent in data from the polar regions implying that estimating correct abundance levels for these molecules might be challenging in these cases; and (3) the time-resolved thermal emission spectrum encodes information about seasons/planetary obliquity, but the significance depends on the viewing geometry and spectral band considered.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SOLENER.2019.05.004", "year": 2019, "title": "Prediction of time series for several hours of surface solar irradiance using one-granule cloud property data from satellite observations", "abstract": "Satellite observation is one of the most useful methods for monitoring the power generated by photovoltaic systems. We propose a method for predicting time series of the surface solar irradiance (SSI) from one-granule cloud properties data obtained by satellite observation. This method has two parts. One is prediction of time series features from cloud properties, which is based on a previous study. The other is prediction of a time series from time series features, which is developed in this work. Seven time series features are used: mean, standard deviation, skewness, kurtosis, linear regression coefficient, autocorrelation coefficient with lag-1, and sample entropy. The prediction skill is characterized in two ways: by the distance between the predicted and observed time series (metric D), and by the similarity of the spectrum between the two time series (metric S). Verifying the time series prediction method from time series features shows that the mean and linear regression coefficient are the first and second most influential factors for metric D, and standard deviation and autocorrelation coefficient with lag-1 are those for metric S. The prediction skill of the prediction method for the time series features from cloud properties is also verified, indicating that predictors for the mean, standard deviation lag-1 autocorrelation coefficient, and sample entropy have sufficient prediction skill, measured by the standardized root mean square error. Finally, the two methods are integrated to construct the prediction system using four time series features. The overall skill of the prediction system for the time series is evaluated. The proposed system provides information about the strength of the SSI time series and its variation for several hours over the satellite observation area.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/ACP-21-18689-2021", "year": 2021, "title": "Variability and trends in surface solar spectral ultraviolet irradiance in Italy: on the influence of geopotential height and lower-stratospheric ozone", "abstract": "Abstract. The short- and long-term variability of the surface spectral solar ultraviolet (UV) irradiance is investigated across Italy using high-quality ground-based measurements from three locations: Aosta (45.7 N, 7.4 E, 570 m a.s.l.), Rome (41.9 N, 12.5 E, 15 75 m a.s.l.), and Lampedusa (35.5 N, 12.6 E, 50 m a.s.l.). The three sites are characterized by different environmental conditions and represent almost the full latitudinal extent of the Italian territory. Data of two periods were analysed: 20062020 (all sites) and 19962020 (Rome only). The main objective of this study is to quantify the effect of the geopotential height (GPH) at 250 hPa on total ozone, and spectral irradiance at 307.5 and 324 nm. We first show that monthly anomalies in GPH, total ozone, and spectral irradiances are correlated amongst the three sites, suggesting that Italy is often affected by the same synoptical weather systems. We further find statistically significant anticorrelations between GPH and monthly anomalies in total ozone for all stations and months. Conversely, we identify positive correlations between GPH and monthly anomalies in spectral irradiance at 307.5 nm for most months. The influence of GPH on short-term variability also hold for long-term trends. For example, long-term changes in total ozone over the period 20062020 were associated with changes in GPH for all stations. This suggests that observed negative trends in total ozone were mainly driven by changes in lower-stratospheric ozone as upper-stratospheric ozone was increasing over this period. For several months of the year, positive trends in UV irradiance were observed, and we found that these trends were predominantly caused by changes in clouds and/or aerosols instead of total ozone. For the longer period of 19962020, a statistically significant annualized decrease in total ozone of 0.1 % per year was identified for Rome and could subsequently be attributed to decreasing lower-stratospheric ozone. While positive trends in spectral irradiance at 307.5 nm were observed for several months of this extended period, the negative trend in total ozone did not lead to a positive trend in the spectral irradiance at 307.5 nm in the deseasonalized data. Our study provides evidence that dynamical processes taking place in the troposphere lead to significant variability in total ozone and surface solar UV irradiance.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1175/JAMC-D-21-0249.1", "year": 2022, "title": "Quantification of Effects of Errors in the Cloud Properties on the Representation of the Surface Downward Shortwave Flux Based on MERRA-2 in Japan", "abstract": "Abstract The evaluation of the representation of the surface downward shortwave flux (DSF) from atmospheric reanalysis data products is required to obtain reliable information for the resource assessment of surface solar energy. The representation of the DSF from the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), reanalysis data product was evaluated using surface solar radiation from ground-based observations in Japan. The cloud fraction (CFR) and cloud optical thickness (COT) from Moderate Resolution Imaging Spectroradiometer (MODIS) were also used as references. The CFR from MERRA-2 tends to be smaller than that from MODIS, and the correlation between the difference in the CFR and that in the DSF is negative. The correlation between the difference in the COT and that in the DSF is weakly negative. To quantify the effects of the difference in the CFR and COT to that of the DSF, a regression model based on an artificial neural network architecture that emulates the process of the DSF in MERRA-2 was constructed. Numerical experiments using the emulator quantify contributions of each of the differences in the CFR and COT and joint contributions of the two variables. In addition, a cluster analysis was performed to clarify the differences in the seasonal changes in the monthly mean bias error (MBE) in the DSF among ground observation stations, and three clusters were identified. Contributions of the differences in the CFR and COT to the seasonal change in the monthly MBE were also clarified using the results of the numerical experiments.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1002/2017GL076472", "year": 2018, "title": "Tailoring Meridional and Seasonal Radiative Forcing by Sulfate Aerosol Solar Geoengineering", "abstract": "We study the possibility of designing solar radiation management schemes to achieve a desired meridional radiative forcing (RF) profile using a two-dimensional chemistry-transport-aerosol model. Varying SO2 or H2SO4 injection latitude, altitude, and season, we compute RF response functions for a broad range of possible injection schemes, finding that linear combinations of these injection cases can roughly achieve RF profiles that have been proposed to accomplish various climate objectives. Globally averaged RF normalized by the sulfur injection rate (the radiative efficacy) is largest for injections at high altitudes, near the equator, and using emission of H2SO4 vapor into an aircraft wake to produce accumulation-mode particles. There is a trade-off between radiative efficacy and control as temporal and spatial control is best achieved with injections at lower altitudes and higher latitudes. These results may inform studies using more realistic models that couple aerosol microphysics, chemistry, and stratospheric dynamics.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/978-981-15-5955-6_93", "year": 2020, "title": "Assessment of Floating Solar Photovoltaic (FSPV) Potential in India", "abstract": "This study deals with an assessment of the potential of utility-scale floating solar photovoltaic (FSPV) plants in India. Global Solar Atlas (GSA) and Global Reservoir and Dam (GRanD) databases are used for examining water bodies such as man-made reservoirs used for hydroelectricity generation, irrigation, drinking water purposes, and few lakes in India. Considering 10% coverage of water surface area by FSPV systems, a gross potential estimate of 124.6 GWp is arrived at. Further screening by fixing technological and other criteria limits the potential to 111.9 GWp.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.SOLENER.2018.01.003", "year": 2018, "title": "Prediction of the day-ahead clear-sky downwelling surface solar irradiances using the REST2 model and WRF-CHIMERE simulations over the Arabian Peninsula", "abstract": "The forecasting of the downwelling surface solar irradiances is required by the operators of solar powered plants to predict the power output of the plant. The purpose of this study is to use aerosol optical depth and columnar water vapor forecasts by the chemistry transport model CHIMERE, coupled with the Weather Research and Forecast (WRF) model, as inputs in the REST2 model to predict the day-ahead clear-sky global horizontal, direct normal and diffuse horizontal irradiances at hourly steps. A dataset of quality-assured and cloud-screened surface solar irradiance measurements collected from 44 sites scattered throughout Saudi Arabia was used to validate the predicted surface solar irradiances. The validation for the day-ahead forecasting of the clear-sky global horizontal irradiance for the data of all 44 stations combined exhibits a bias (relative to the mean reference value) of 0%, a relative root mean square error of 4% and a correlation coefficient of 0.993. Respectively, the clear-sky direct normal irradiance exhibits values of 0%, 15% and 0.769, while the clear-sky diffuse horizontal irradiance values are 0%, 35% and 0.542. The errors in the inputs are also investigated. The results are satisfactory and pave the way to the inclusion of the attenuation due to clouds with the final aim of predicting the surface solar irradiance under all-sky conditions.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2002JD002852", "year": 2003, "title": "Effects of absorbing aerosols on the determination of the surface solar radiation", "abstract": "Coincident and collocated measurements of solar radiation from the Scanner for Radiation Budget (ScaRaB) on Meteor-3 and from towers in a boreal forest region during the Boreal Ecosystems and Atmosphere Study (BOREAS) period are used to evaluate an algorithm of [1993a] which was developed to derive the net surface solar radiation flux from satellite measurements. The analysis shows that after correcting for mismatching between the footprints of the tower measurements and the satellite pixels, there is a substantial bias that is due to the presence of absorbing aerosols. Application of the aerosol correction term of [1995] reduces the mean bias to about 5 W m-2. Cloud radiation forcing ratio R has been used in many studies to address the issue of a cloud absorption anomaly. Three methods, each with a different approach to the consideration of the effect on radiative fluxes by absorbing aerosols, are used to calculate R. Methods that account inadequately for aerosol effects when applied to the coincident and collocated tower and satellite measurements give large values of R (1.28-1.42) under conditions of heavy aerosol loading, which could be interpreted as an indication of a cloud absorption anomaly. However, application of the method that accounts best for aerosol effects gives values of R within the range 1.08\u223c1.18 and so does not support the idea of anomalous cloud absorption.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/AMT-13-3893-2020", "year": 2020, "title": "Optimised degradation correction for SCIAMACHY satellite solar measurements from 330 to 1600 nm by using the internal white light source", "abstract": "Abstract. SCIAMACHY (SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY) on-board the European Environmental Satellite (Envisat) provided spectrally resolved measurements in the wavelength range from 0.24 to 2.4 m by looking into the Earth's atmosphere using different viewing geometries (limb, nadir, solar, and lunar occultation). These observations were used to derive a multitude of parameters, in particular atmospheric trace gas amounts. In addition to radiance measurements solar spectral irradiances (SSIs) were measured on a daily basis. The instrument was operating for nearly a decade, from August 2002 to April 2012. Due to the harsh space environment, it suffered from continuous optical degradation. As part of recent radiometric calibration activities an optical (physical) model was introduced that describes the behaviour of the scanner unit of SCIAMACHY with time (Krijger et al., 2014). This model approach accounts for optical degradation by assuming contamination layers on optical surfaces in the scanner unit. The variation in layer thicknesses of the various optical components is determined from the combination of solar measurements from different monitoring light paths available for SCIAMACHY. In this paper, we present an optimisation of this degradation correction approach, which in particular improves the solar spectral data. An essential part of the modification is the use of measurements from SCIAMACHY's internal white light source (WLS) in combination with direct solar measurements. The WLS, as an independent light source, therefore, gives an opportunity to better separate instrument variations and natural solar variability. However, the WLS emission depends on its burning time and changes with time as well. To use these measurements in the optimised degradation correction, the change in the WLS emission in space needs to be characterised first. The changes in the WLS with accumulated burning time are in good agreement with detailed laboratory lamp studies by Sperling et al. (1996). Although the optimised degradation-corrected SCIAMACHY SSIs still show some instrumental issues when compared to SSI measurements from other instruments and model reconstructions, our study demonstrates the potential for the use of an internal WLS for degradation monitoring.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ASR.2017.01.036", "year": 2017, "title": "Semi-analytical solar radiation pressure modeling for QZS-1 orbit-normal and yaw-steering attitude", "abstract": "Solar radiation pressure (SRP) is the dominant non-gravitational perturbation of global navigation satellite system (GNSS) satellites. In the absence of detailed surface models, empirical SRP models, such as the Empirical CODE Orbit Model (ECOM), are widely used in practice for GNSS orbit determination but may require an undue number of parameters to properly describe the actual motion. Building up on previous research for spacecraft in yaw-steering (YS) attitude, analytical expressions for the SRP acceleration in orbit-normal (ON) attitude are established based on a generic box-wing model, and related to the corresponding parameters of the ECOM. The results are used to obtain an a priori SRP model for the QZS-1 satellite of the Quasi Zenith Satellite System (QZSS), which achieves a modeling accuracy of about 1nm/s2 using as little as 6 parameters. To compensate remaining modeling deficiencies, we combine the analytical a priori model with a complementary set of five empirical parameters based on an ECOM-type formulation. QZS-1 orbits based on the resulting semi-analytical SRP model exhibit a better than 10cm RMS consistency with satellite laser ranging measurements for both YS and ON attitude modes, which marks a 24 times improvement over legacy orbit products without a priori model.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.SOLENER.2021.01.017", "year": 2021, "title": "How changes in worldwide operating conditions affect solar cell performance", "abstract": "In field operation, solar cells are exposed to constantly changing operating conditions. These changing conditions have an impact on energy yield. Present-day yield predictions mostly use linear correction coefficients derived from lab experiments. These corrections neglect interactions between meteorological parameters like temperature and humidity. In this study, we reverse this approach by analyzing simulated solar cell performance under varying conditions worldwide. We use meteorological data measured between 2006 and 2015 to establish trends in the development of meteorological conditions and solar cell performance. From these two trends, we obtain linear correlation coefficients. The obtained implied temperature coefficient, on average, has a value of 0.52 0.03%/K. This value is 15% higher than the tabulated temperature coefficient (0.45%/K) used in the simulation, demonstrating the impact of coinciding meteorological factors. Light absorption due to elevated humidity levels is likely the strongest contributor to the deviation. One application of these findings is a projection of how today's crystalline silicon solar panels would perform due to rising temperature at the end of the 21st century. Using the established implied temperature coefficient, we project performance reductions of between 0.7% and 2.5%, depending on the warming scenario. The effect is reduced in higher efficient, upcoming photovoltaic technologies, providing further motivation to develop and improve these solar cells.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2022.01.027", "year": 2022, "title": "An optimized approach for mapping solar irradiance in a mid-low latitude region based on a site-adaptation technique using Himawari-8 satellite imageries", "abstract": "Solar technologies play an important role in the renewable electric energy budget, so accurate solar maps are a crucial point for finding a suitable place for solar panel installation. This study proposes a method for solar irradiance mapping in mid-low latitude regions, and the method's site-adaptation process is performed by optimizing the Heliosat method through the REST2 clear-sky model, cloud albedo selection, new clear-sky index, and linear subtraction for bias removal. A local station with two pyranometers provided ground measurements. Site-adapted model results were used to create a calibrated solar map by linear regression adaptation. This study also provides the evaluation and site-adaption of another irradiance dataset in the Asian region from the Japan Aerospace Exploration Agency (JAXA). Heliosat model results with optimal cloud albedo showed high accuracy of 4.78 W/m2 MBE and 63.11 W/m2 RMSE, which can be improved using the site-adaptation process to 0.71 W/m2 MBE and 57.42 W/m2 RMSE. The selection of an optimal cloud albedo improved the model by approximately 20%. The JAXA dataset obtained a large overestimation of 56.72 W/m2 MBE, thereby highlighting the importance of site adaptation. This research's findings pave a new way for the creation of accurate site-adapted solar maps and databases.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ASR.2018.05.036", "year": 2018, "title": "Ray-tracing solar radiation pressure modeling for QZS-1", "abstract": "Precise orbit determination requires accurate models for the orbital perturbations. Next to the well-known gravitational forces, the solar radiation pressure (SRP) is the main perturbation for navigation satellites. SRP results from the interaction between the photons of the Sun and the surfaces of the satellite. Hence, its modeling depends on proper knowledge of the geometry and optical properties of the satellite. Previous work showed that the use of an a priori box-wing model for the SRP significantly improves the estimated orbit products as well as orbit predictions compared to purely empirical models. However, the presently available box-wing models for the first satellite of the Japanese Quasi-Zenith Satellite System, QZS-1, do not consider an accurate geometry. Based on a computer-aided design model of the QZS-1 satellite, a ray-tracing simulation is performed to compute SRP accelerations in a more realistic manner. The resulting SRP model is validated through QZS-1 precise orbit determination over a two year data arc covering yaw-steering and orbit-normal attitude regimes. In yaw-steering mode, the ray-tracing model shows a better overall performance than a box-wing model and improves the standard deviation of QZS-1 satellite laser ranging residuals by a factor of three compared to orbits without a priori model. On the other hand, the ray-tracing SRP model does not account for thermal accelerations and thus performs worse than an adjusted box-wing model in orbit-normal mode.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.RSER.2020.110318", "year": 2020, "title": "Annual and interannual complementarities of renewable energy sources in Colombia", "abstract": "The Colombian power sector is highly dependent on hydroelectricity, making it vulnerable to both annual dry seasons and the droughts brought by the El Nino-Southern Oscillation (ENSO). One efficient way to reduce such vulnerabilities is by introducing renewable energies that may complement the availability of hydroelectricity. This paper explores the degree of complementarity between solar and wind resources in Colombia and the country's hydropower sector, on both annual and interannual scales. Various correlation analyses are performed over four climatic variables: water inputs (runoff), precipitation, solar radiation, and wind speed, plus the Oceanic Nino Index (ONI), which helps to characterize ENSO events. The analysis is carried out over different geographic locations and seasons. The results indicate that solar and wind resources, particularly those in the Caribbean Coast and the central Andes regions, complement the hydropower sector during both the dry seasons of the annual climatological cycle and ENSO's warm and cold phases. Also, they show that complementarity varies, not just with the type of sources and location, but also with the seasons of the year and ENSO's stage of development. This paper provides an enhanced perspective on the behavior of renewables and offers an alternative viewpoint for designing the future expansion of power systems.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2022.08.149", "year": 2022, "title": "The economic value of photovoltaic performance loss mitigation in electricity spot markets", "abstract": "Photovoltaic (PV) performance is affected by reversible and irreversible losses. These can typically be mitigated through responsive and proactive operations and maintenance (O&M) activities. However, to generate profit, the cost of O&M must be lower than the value of the recovered electricity. This value depends both on the amount of recovered energy and on the electricity prices, which can vary significantly over time in spot markets. The present work investigates the impact of the electricity price variability on the PV profitability and on the related O&M activities in Italy, Portugal, and Spain. It is found that the PV revenues varied by 1.6 to 1.8 within the investigated countries in the last 5 years. Moreover, forecasts predict higher average prices in the current decade compared to the previous one. These will increase the future PV revenues by up to 60% by 2030 compared to their 20152020 mean values. These higher revenues will make more funds available for better maintenance and for higher quality components, potentially leading to even higher energy yield and profits. Linearly growing or constant price assumptions cannot fully reproduce these expected price trends. Furthermore, significant price fluctuations can lead to unexpected scenarios and alter the predictions.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3389/FEART.2021.769844", "year": 2021, "title": "A Cloudier Picture of Ice-Albedo Feedback in CMIP6 Models", "abstract": "Increased solar absorption is an important driver of Arctic Amplification, the interconnected set of processes and feedbacks by which Arctic temperatures respond more rapidly than global temperatures to climate forcing. The amount of sunlight absorbed in the Arctic is strongly modulated by seasonal ice and snow cover. Sea ice declines and shorter periods of seasonal snow cover in recent decades have increased solar absorption, amplifying local warming relative to the planet as a whole. However, this Arctic albedo feedback would be substantially larger in the absence of the ubiquitous cloud cover that exists throughout the region. Clouds have been observed to mask the effects of reduced surface albedo and slow the emergence of secular trends in net solar absorption. Applying analogous metrics to several models from the 6\r\n \r\n th\r\n \r\n Climate Model Intercomparison Project (CMIP6), we find that ambiguity in the influence of clouds on predicted Arctic solar absorption trends has increased relative to the previous generation of climate models despite better agreement with the observed albedo sensitivity to sea ice variations. Arctic albedo responses to sea ice loss are stronger in CMIP6 than in CMIP5 in all summer months. This agrees better with observations, but models still slightly underestimate albedo sensitivity to sea ice changes relative to observations. Never-the-less, nearly all CMIP6 models predict that the Arctic is now absorbing more solar radiation than at the start of the century, consistent with recent observations. In fact, many CMIP6 models simulate trends that are too strong relative to internal variability, and spread in predicted Arctic albedo changes has increased since CMIP5. This increased uncertainty can be traced to increased ambiguity in how clouds influence natural and forced variations in Arctic solar absorption. While nearly all CMIP5 models agreed with observations that clouds delay the emergence of forced trends, about half of CMIP6 models suggest that clouds accelerate their emergence from natural variability. Isolating atmospheric contributions to total Arctic reflection suggests that this diverging behavior may be linked to stronger Arctic cloud feedbacks in the latest generation of climate models.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S12517-021-07999-Z", "year": 2021, "title": "Evaluation the efficiency of a parametric model based on MODIS data for solar radiation estimation in comparison with some empirical models", "abstract": "In the present study, the output of several empirical models for estimating solar radiation and the output of a model based on data obtained from moderate resolution imaging spectroradiometer (MODIS) sensor (parametric model) are compared with ground observational station to introduce a suitable algorithm for estimating solar radiation in the studied stations. For this purpose, first the selected empirical models were calibrated according to the climatic conditions of the study area and then used to estimate solar radiation. To this aim, empirical models were evaluated based on suitably partitioned datasets. 75% of the total data were utilized for training phase and the remaining 25% data were used for testing phase and conducting statistical analysis. In the next step, the parametric model (SBDART) were tested and used for predicting the solar radiation data in target stations. The results indicated that the R2 value of models vary between 0.25 to 0.95, most of which are related to the Santa Barbara DISORT (discrete ordinates radiative transfer) atmospheric radiative transfer (SBDART) (R2=0.95) and calibrated Angstrom models (R2=0.89), respectively. The mean absolute percentage error of the SBDART model is significantly different from other models (MAPE=4.3%). After that, the lowest MAPE (mean absolute percentage error) is related to the Angstrom model (MAPE =5.98%). In addition, the parametric model is more efficient on cloudy days than on cloudless days so that the calculated RMSE (root mean square error) and MBE (mean bias error) indices are 9.07 W/m2.day and -0.72 W/m2.day for cloudy days, and 19.77 W/m2.day and 3.60 W/m2.day for cloudless days. In contrast, the empirical Angstrom-Prescott model had better results with observational data on cloudless days so that the indices were RMSE =43.60 W/m2.day and MBE =34.25 W/m2.day for cloudy days, and RMSE =29.56 W/m2.day and MBE= 6.19 MJ/m2.day for cloudless days.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2020JD034090", "year": 2021, "title": "Changes in clear\u2010sky shortwave aerosol direct radiative effects since 2002", "abstract": "A new method for determining clear sky shortwave aerosol direct radiative effects (ADRE) from the Clouds and the Earth's Radiant Energy System is used to examine changes in ADRE since 2002 alongside changes in aerosol optical depth (AOD) from the Moderate Resolution Spectroradiometer. At global scales, neither ADRE nor AOD show a significant trend. Over the northern hemisphere (NH), ADRE increases by 0.18 \u00b1 0.17 Wm\u22122 per decade (less reflection to space) but shows no significant change over the southern hemisphere. The increase in the NH is primarily due to emission reductions in China, the United States, and Europe. The COVID 19 shutdown shows no noticeable impact on either global ADRE or AOD, but there is a substantial influence over northeastern China in March 2020. In contrast, February 2020 anomalies in ADRE and AOD are within natural variability even though the impact of the shutdown on industry was more pronounced in February than March. The reason is because February 2020 was exceptionally hot and humid over China, which compensated for reduced emissions. After accounting for meteorology and normalizing by incident solar flux, February ADRE anomalies increase substantially, exceeding the climatological mean ADRE by 23%. February and March 2020 correspond to the only period in which adjusted anomalies exceed the 95% confidence interval for 2 consecutive months. Distinct water land differences over northeastern China are observed in ADRE but not in AOD. This is likely due to the influence of surface albedo on ADRE in the presence of absorbing aerosols.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1117/12.2325373", "year": 2018, "title": "Surface irradiance estimations on watercourses with remote sensing data", "abstract": "The vegetation in the riparian zone of a watercourse influences the water state with multiple factors, first via direct substance discharge and secondly via shadow casting on the water surface. Shadowing directly regulates the solar radiant energy arriving at the water surface. Solar radiation input to aquatic environments is the most important abiotic factor for aquatic flora and fauna habitat development. Thus, to adequately asses the ecological state of water courses it is necessary to quantify the solar surface irradiance E (W/m2) arriving on the water surface. When estimating the solar surface irradiance the complex coherence between incoming solar radiation, atmospheric influences, and spatial-temporal geometries need to be investigated. This work established a work flow to compute the solar surface irradiance for water bodies using different remote sensing data. The work flow was tested on regional level for a section of the river Freiberger Mulde, Saxony, for the year 2016. Product of the calculations is a map visualising the annual sum of the solar surface irradiance (kWh/m2) arriving on the Freiberger Mulde water surface and the surrounding terrain. Based on these information bio-hydrological issues can be further examinated.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2020JD032430", "year": 2020, "title": "Validation of SAGE III/ISS Solar Occultation Ozone Products With Correlative Satellite and GroundBased Measurements", "abstract": "The Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) was launched on 19 February 2017 and began routine operation in June 2017. The first 2 years of SAGE III/ISS (v5.1) solar occultation ozone data were evaluated by using correlative satellite and ground-based measurements. Among the three (MES, AO3, and MLR) SAGE III/ISS retrieved solar ozone products, AO3 ozone shows the smallest bias and best precision, with mean biases less than 5% for altitudes ~15-55 km in the midlatitudes and ~20-55 km in the tropics. In the lower stratosphere and upper troposphere, AO3 ozone shows high biases that increase with decreasing altitudes and reach ~10% near the tropopause. Preliminary studies indicate that those high biases primarily result from the contributions of the oxygen dimer (O4) not being appropriately removed within the ozone channel. The precision of AO3 ozone is estimated to be ~3% for altitudes between 20 and 40 km. It degrades to ~10-15% in the lower mesosphere (~55 km) and ~20-30% near the tropopause. There could be an altitude registration error of ~100 m in the SAGE III/ISS auxiliary temperature and pressure profiles. This, however, does not affect retrieved ozone profiles in native number density on geometric altitude coordinates. In the upper stratosphere and lower mesosphere (~40-55 km), the SAGE III/ISS (and SAGE II) retrieved ozone values show sunrise/sunset differences of ~5-8%, which are almost twice as large as what was observed by other satellites or model predictions. This feature needs further study.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2020JC016958", "year": 2021, "title": "An improved ocean surface albedo computational scheme: Structure and Performance", "abstract": "Ocean surface albedo (OSA) is an important factor for the transfer of radiation in the coupled atmosphere-ocean system. By resolving the spectral variations of the reflective properties for incident direct and diffuse solar radiation, we develop an OSA computational scheme to study the impact of ocean biogeochemistry on the air-sea boundary condition of solar radiative transfer in the atmosphere. The new scheme is implemented for the General Circulation Model applications of the shortwave rapid radiative transfer model RRTMG_SW, a radiative transfer model used extensively in regional and global models. We show that a number of OSA schemes lead to underestimated results in comparison with in-situ measurements obtained at a site 25 km east of Virginia Beach. The scheme developed in this study considers multiple influential factors and is robust in terms of the mean absolute percentage error (MAPE) and the root mean square error in comparison with in-situ measurements. Furthermore, the new simulations are highly consistent with the Clouds and the Earth's Radiant Energy System (CERES) OSA distribution on a global scale. However, the theoretical results show slight differences compared with the CERES OSA under all sky conditions and overestimate the OSA in the subpolar Southern Ocean under clear sky conditions. The assumption of a uniform phase function, which neglects the spatial variability of the optical properties of oceanic particles, is largely responsible for the primary source of uncertainties in an OSA scheme.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.AGRFORMET.2022.109222", "year": 2022, "title": "Quantifying the impacts of DEM uncertainty on clear-sky surface", "abstract": "Accurate estimation of shortwave radiation in mountains will advance our knowledge of climate change effects, especially on mountain ecosystems. Recently, some approaches have been developed to estimate shortwave radiation parameters in mountains with satellite data, but few attempts were made to understand the impacts of digital elevation model (DEM) uncertainty on estimates. Our study investigates such impacts quantitatively in clear-sky conditions at multiple spatial and temporal scales (30-3000 m, instantaneous to daily). We employed a retrieval algorithm to estimate instantaneous and daily mean clear-sky downward shortwave radiation (DSR) and net shortwave radiation (NSR), as a proxy for our evaluation. The accuracy of our method based on accurate terrain data was verified against in-situ measurements with root-mean-square errors (RMSEs) of 65.9 W /m2 and 65.1 W /m2 for instantaneous DSR and NSR, and 21.2 W /m2 and 22.5 W /m2 for daily mean values, respectively. When using satellite DEM products, the DSR estimation uncertainty could increase by 64.0% for instantaneous values and 46.2% for daily mean values. Using AW3D30 and SRTM DEMs for DSR estimation led to a maximum difference of 16.8% (103.6 W /m2) and 13.0% (25.8 W /m2) on instantaneous and daily mean values, respectively. That estimation difference of shortwave radiation decreased with an increase in spatial scale, with RMS deviation lower than 2% for spatial resolution beyond 3000 m. In addition, the evaluation of introducing random errors into AW3D30 DEM showed that the shortwave radiation uncertainty caused by DEM may exceed the algorithm uncertainty itself with DEM mean absolute error (MAE) equaling about 5.0 m. Considering the current DEM accuracy, the impacts of DEM errors on shortwave radiation in mountains cannot be ignored. This study emphasizes the potential impacts of DEM uncertainty on surface shortwave radiation estimation, which is crucial in using satellite-derived datasets for energy balance calculation and climate change applications in mountains.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S10669-017-9637-6", "year": 2017, "title": "Downward shortwave radiation estimation and spatial assessment on sites over complex terrain applying integrative approach of MTCLIM-XL, interpolation, RS and GIS", "abstract": "Downward shortwave radiation (DSR) is a highly variable solar source on spatiotemporal basis and essential for energy and agriculture systems, while its calculations are helpful in the environment-related studies, climatology, and monitoring fire risk. Statistical methods developed to extrapolate values of climatic variables and radiation could fail to generate reliable findings of DSR over a complex terrain without considering local topographic factors. In the present study, we proposed an integrative approach of MTCLIM-XL extrapolation with remote sensing (RS) and geographic information system (GIS) to estimate real-time DSR and its spatial potential over surfaces of contrasting elevated sites on a mountainous terrain of Quetta (Pakistan).Based on methodological approach, remote sensing data product of high-resolution DEM (SRTM 30m) was processed to extract topographic data, and meteorological data were obtained from a base site, Subsequently, MTCLIM-XL executed the simulation to calculate the daily-based DSR (W/m2).Spatial distribution of DSR was generated by applying deterministic interpolation with complementing quantification of Hillshade analysis for spatially obstructive surfaces, and resultant spatial hotspot-based potential was assessed on basis of specified threshold level (above 250 W/m2 = 2 kW h/m2) over the specified area. We observed usable potential of DSR at target sites and its spatial distribution during the study period of 2015 to April 2016. Using EUMETSAT CMSAF data as a standard, the validation demonstrates agreeable results of low RMSE and high correlation coefficient values for selected sites, except some sites with relatively high elevations and irregular gradients. Analysis of solar zenith angle to evaluate its inverse relation with increment in DSR values shows agreeable high inverse relation, while the negative trend for only some sites features relatively high rugged topography. In conclusion, MTCLIM-XL with RS and GIS integration manifests as a reliable approach for estimation and spatial potential assessment-based exploration of DSR over complex terrain having no ground data, while prospectively it will complement to the environment-related studies on local to mesoscale.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ENPOL.2020.111293", "year": 2020, "title": "The wider regional benefits of power grids improved resilience through tree-trimming operations evidences from Connecticut, USA", "abstract": "Tree-trimming operations (TTOs) are expensive, yet popular management practices for increasing power-grid reliability. In this work, we investigate and identify the relationship between TTOs and power outages and quantify the regional economic benefits TTOs provide in the three years following these operations. Our data focus on a portion of Connecticut, for 20092015. We find that even a limited application of TTOs reduce outages substantially. We combine this result with an advanced economic model to estimate the benefits to the state. We find that this reduction in outages translates in to considerable savings for the state's economy, justifying expansion of TTOs.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S00382-019-04966-Z", "year": 2019, "title": "Modeling study of the impact of complex terrain on the surface energy and hydrology over the Tibetan Plateau", "abstract": "The long-term effects of complex terrain on solar energy distributions and surface hydrology over the Tibetan Plateau (TP) are investigated using the 4th version of the global Community Climate System Model (CCSM4) coupled with a 3-D radiative transfer (RT) parameterization. We examine the differences between the results from CCSM4 with the 3-D RT parameterization and the results from CCSM4 with the plane-parallel RT scheme. In January (winter), the net surface solar flux (FSNS) displays negative deviations over valleys and the north slopes of mountains, especially in the northern margin of the TP, as a result of the 3-D shadow effect. Positive deviations in FSNS in January are found over the south slopes of mountains and over mountain tops, where more solar flux is intercepted. The deviations in total cloud fraction and snow water equivalent (SWE) exhibit patterns opposite to that of FSNS. The SWE decreases due to the 3-D mountain effect in spring and the magnitude of this effect depends on the terrain elevations. The SWE is reduced by 117 mm over the TP in April, with the largest decrease in SWE at an elevation of 3.54.5 km. Negative deviations in precipitation are found throughout the year, except in May and December, and they follow the seasonal variations in the deviations in total cloud fraction. The total liquid runoff at 3.54.5 km elevation increases in April due to earlier (March) snowmelt caused by increased downward solar radiation. The possible deviations in surface energy and SWE over the TP, caused by plane-parallel assumption in most climate models may result in biases in the liquid runoff and the river water resources over the TP and downstream.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2022JD036449", "year": 2022, "title": "Development of a Clear-Sky 3D Sub-Grid Terrain Solar Radiative Effect", "abstract": "Terrains strongly affect the surface solar radiation (SSR) and energy balance, and further greatly modulate the weather and climate in rugged areas. In this study, we have developed a clear-sky 3-dimensional sub-grid terrain solar radiative effect (3DSTSRE) parameterization scheme based on the mountain radiation theory with full consideration of the influences of 3-dimensional configuration of terrains. Results show that the 3DSTSRE scheme achieves the equivalent effect of the downward SSR flux at the model grids derived from those explicitly calculated at the sub-grids without reducing the calculating efficiency of numerical models. It performs well at model grids with different horizontal resolutions. The instant downward SSR flux calculated by the 3DSTSRE scheme at 76.8%, 84.8%, 88.7%, 91.6%, 93.0%, and 87.1% model grids with the horizontal resolution of 0.025\u00b0, 0.05\u00b0, 0.1\u00b0, 0.2\u00b0, 0.4\u00b0, and 0.8\u00b0 in the areas featured by complex terrains shows relative errors within \u00b11.0% against those derived from the explicit calculations at sub-grids, respectively. The normalized mean absolute errors of the instant downward SSR flux calculated by the 3DSTSRE scheme are below 1% (2%) throughout the day and the year for the model grids with resolutions ranging from 0.05\u00b0 to 0.8\u00b0 (of 0.025\u00b0). Although the performance of 3DSTSRE scheme decreases slightly under the conditions with much lower solar zenith angle and finer model horizontal resolution, the 3DSTSRE scheme developed in current study shows broad application prospects in various numerical models with the advantages of a solid physical foundation, high accuracy, strong portability and flexibility.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/AMT-16-75-2023", "year": 2023, "title": "Solar occultation measurement of mesospheric ozone by SAGE III/ISS: impact of variations along the line of sight caused by photochemistry", "abstract": "Abstract. Twilight gradients in the concentration of atmospheric species\nwith short photochemical lifetimes influence the transmission data obtained\nin a solar occultation instrument, such as the Stratospheric Aerosol and Gas Experiment III aboard the International Space Station (SAGE III/ISS). These photochemically induced changes result in nonlinear asymmetries in the species distribution near the tangent altitude along the line of sight\n(LOS). The bias introduced by neglecting the effects of twilight variations\nin the retrieval of mesospheric ozone is the focus of this study. Ozone (O3) in the mesosphere exhibits large variations near the terminator during sunrise\nand sunset based on current understanding of the photochemistry of this\naltitude region. The algorithm used in the SAGE III/ISS standard retrieval\nprocedure for mesospheric ozone does not include the effects of these\ngradients. This study illustrates a method for implementing a correction\nscheme to account for the twilight variations in mesospheric O3 and\ngives an estimate of the bias in the standard retrieval. We use the results\nfrom a diurnal photochemical model conducted at different altitudes to\ndevelop a database of ratios of mesospheric O3 at different solar\nzenith angles (SZA) around 90 to O3 at a SZA of\n90 for both sunrise and sunset conditions. These ratios are used\nto scale the O3 at levels above the tangent altitude for appropriate\nSZA in the calculation of the optical depth along the LOS. In general, the\nimpact of the corrections due to twilight variations is to increase the\ncontribution of the overlying layers to the optical depth thereby reducing\nthe retrieved O3 concentration at the tangent altitude. We find that\nat sunrise the retrieved mesospheric O3 including the diurnal\ncorrections is lower by more than 30 % compared to the archived O3.\nWe show the results obtained for different latitudes and seasons. In\naddition, for nearly collocated sunrise and sunset scans, we note that these\ncorrections lead to better qualitative agreement in the sunrise to sunset\nO3 ratio with the photochemical model prediction.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1117/12.2630361", "year": 2022, "title": "Solar spectral irradiance reconciliation of SORCE and TSIS1 SIM", "abstract": "The Solar Radiation and Climate Experiment (SORCE) recorded daily Solar Spectral Irradiance (SSI) measurements from 2003 to 2020, overlapping with the Total and Spectral Irradiance Sensor (TSIS1) for 2 years (Mar. 2018 - Feb. 2020). We use data from the Spectral Irradiance Monitors (SIM), spanning 704 days and 554 time-matched observations, to compare absolute irradiance calibrations in a truly unique space-based UV-IR spectroscopic overlap study. This 2002400 nm comparison was conducted during the Solar Cycle 24 minimum, so observed differences are likely instrumental. We find peak-to-peak (maximum) absolute scale differences of 12% with a mean fractional difference of 0.7 2.9%. A multiplicative scale correction factor (STICR) has been developed to reconcile the TSIS1 and SORCE SIM irradiance differences. Applying this correction to the SORCE-SIM V27 dataset, we provide a re-calibrated dataset known as the TSIS1-SIM Adjusted Values (TAV). We discuss the challenges in the creation of STICR and TAV, and lessons learned about using temporally overlapping space observatories to provide a continuous solar observation record.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS14010224", "year": 2022, "title": "Updated GOES-13 Heliosat-2 Method for Global Horizontal Irradiation in", "abstract": "Increasing the utilization of renewable energy is at the center of most sustainability policies. Solar energy is the most abundant resource of this type on Earth, and optimizing its use requires the optimal estimation of surface solar irradiation. Heliosat-2 is one of the most popular methods of global horizontal irradiation (GHI) estimation. Originally developed for the Meteosat satellite, Heliosat-2 has been modified in previous work to deal with GOES-13 data and named here GOES_H2. This model has been validated through the computation of indicators and irradiation maps for the Guiana Shield. This article proposes an improved version of GOES_H2, which has been combined with a radiative transfer parameterization (RTP) and the McClear clear-sky model (MC). This new version, hereafter designated RTP_MC_GOES_H2, was tested on eight stations from the Baseline Surface Radiation Network, located in North and South America, and covered by GOES-13. RTP_MC_GOES_H2 improves the hourly GHI estimates independently of the type of sky. This improvement is independent of the climate, no matter the station, the RTP_MC_GOES_H2 gives better results of MBE and RMSE than the original GOES_H2 method. Indeed, the MBE and RMSE values, respectively, change from 11.93% to 2.42% and 23.24% to 18.24% for North America and from 4.35% to 1.79% and 19.97% to 17.37 for South America. Moreover, the flexibility of the method may allow to improve results in the presence of snow cover and rainy/variable weather. Furthermore, RTP_MC_GOES_H2 results outperform or equalize those of other operational models.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1093/ISQ/SQAC030", "year": 2022, "title": "The Geography of Separatist Violence", "abstract": "The literature on separatist groups has paid relatively little attention to groups exact territorial claims and their influence on strategies. We explain the geographic distribution of separatist violence using new geospatial data on the location and extent of groups territorial claims. We argue that variation in where separatists attack stems from variation in how groups allocate effort across two main objectives: control in the claimed region and the coercion of policy concessions from the center. We hypothesize that the relative importance of these objectives derives from features of the claim, the claimed region, and the separatist movement. We show that groups with fuzzy claims that do not follow administrative boundaries or clear geographic features attack more around their envisioned state's border, violence tends to concentrate within the claimed region when it is ethnically heterogeneous or the movement is fragmented, while relatively unified movements attack more in the national capital.\r\n La bibliografia sobre grupos separatistas ha pasado casi por alto los reclamos territoriales exactos y su repercusion en las estrategias que utilizan. Explicamos la distribucion geografica de la violencia separatista con informacion geoespacial nueva sobre la ubicacion y la dimension de los reclamos territoriales de los grupos. Sostenemos que la variacion en los lugares donde atacan los grupos separatistas se debe a la variacion en la forma en que los grupos distribuyen sus esfuerzos en base a dos objetivos principales: el control de la region reclamada y la coercion de las concesiones de politica del centro. Nuestra hipotesis es que la importancia relativa de estos objetivos deriva de las caracteristicas del reclamo, de la region reclamada y del movimiento separatista dado. Demostramos que los grupos con reclamos difusos que no siguen los limites administrativos o las caracteristicas geograficas claras atacan mas alrededor de su frontera de estado visualizada y que la violencia tiende a concentrarse dentro de la region reclamada cuando hay heterogeneidad etnica o cuando el movimiento esta fragmentado, mientras que los movimientos relativamente unidos atacan mas en la capital nacional.\r\n La litterature sur les groupes separatistes a accorde relativement peu d'attention aux revendications territoriales precises de ces groupes et a leur influence sur les strategies. Nous expliquons la repartition geographique de la violence separatiste en nous appuyant sur de nouvelles donnees geospatiales sur la localisation et letendue des revendications territoriales des groupes. Nous soutenons que la variation des lieux d'attaque des separatistes decoule de la variation de la maniere dont les groupes allouent leurs efforts entre deux objectifs principaux : le controle dans la region revendiquee et la coercition de concessions politiques de la part du pouvoir central. Nous emettons l'hypothese que l'importance relative de ces objectifs decoule des caracteristiques de la revendication, de la region revendiquee et du mouvement separatiste. Nous montrons que les groupes dont les revendications sont floues , c'est-a-dire qui ne suivent pas les frontieres administratives ou de caracteristiques geographiques claires, attaquent davantage autour e la frontiere de lEtat qu'ils envisagent et que la violence tend a se concentrer dans la region revendiquee lorsqu'elle est ethniquement heterogene ou que le mouvement est fragmente, alors que les mouvements relativement unifies attaquent davantage dans la capitale nationale.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.APENERGY.2020.114583", "year": 2020, "title": "Changing the policy paradigm: A benefit maximization approach to electricity planning in developing countries", "abstract": "Access to electricity can lead to enhanced education, business, and healthcare opportunities. Governments in emerging economies are often faced with the challenge of increasing access to electricity and reducing system inequality, while operating under severe budget constraints. This paper develops a methodology for finding the optimal expansion of a power system under the objective of maximizing social benefit, as it relates to distributional equality for electricity access, subject to a budget constraint. This contrasts with traditional models, which minimize the cost of satisfying projected electricity demand. We formulate a generation expansion planning problem as a utility-maximization mixed-integer linear program and apply it to a case study analysis of a low-income country with limited electricity infrastructure. We focus our analysis on understanding how the optimal allocation of generation between centralized and distributed resources is impacted by stakeholder preferences toward equality and different budget levels. We find that a high preference for equality leads to lower overall electricity consumption levels, but improved electrification rates due to greater investment (300750 km increase) in transmission infrastructure. If stakeholders move from a low to a high equality preference then they could see a 7287% increase in energy access equality rating depending on the budget. Conversely, indifference to equality leads to higher overall consumption levels in urban areas but reduced electrification rates. This methodology can help decision makers evaluate the social trade-offs between improving energy access, reducing energy inequality and poverty, and increasing total electricity consumption when operating under budget constraints in their countries.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1175/JTECH-D-20-0107.1", "year": 2021, "title": "Changes in toa sw fluxes over marine clouds when estimated via semiphysical angular distribution models", "abstract": "Abstract Top-of-atmosphere (TOA) shortwave (SW) angular distribution models (ADMs) approximateper angular direction of an imagined upward hemispherethe intensity of sunlight scattered back from a specific Earthatmosphere scene. ADMs are, thus, critical when converting satellite-borne broadband radiometry into estimated radiative fluxes. This paper applies a set of newly developed ADMs with a more refined scene definition and demonstrates tenable changes in estimated fluxes compared to currently operational ADMs. Newly developed ADMs use a semiphysical framework to consider cloud-top effective radius ( R e) and above-cloud water vapor (ACWV), in addition to accounting for surface wind speed and clouds phase, fraction, and optical depth. In effect, instantaneous TOA SW fluxes for marine liquid-phase clouds had the largest flux differences (of up to 25 W m2) for lower solar zenith angles and cloud optical depth greater than 10 due to extremes in R e or ACWV. In regions where clouds had persistently extreme levels of R e (here mostly for R e<7 m and R e>15 m) or ACWV, instantaneous fluxes estimated from Aqua, Terra, Meteosat-8, and Meteosat-9 satellites using the two ADMs differed systematically, resulting in significant deviations in daily mean fluxes (up to 10 W m2) and monthly mean fluxes (up to 5 W m2). Flux estimates using newly developed, semiphysical ADMs may contribute to a better understanding of solar fluxes over low-level clouds. It remains to be seen whether aerosol indirect effects are impacted by these updates.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.RENENE.2021.04.048", "year": 2021, "title": "Evaluating the complementarity of solar, wind and hydropower to mitigate the impact of El Ni\u00f1o Southern Oscillation in Latin America", "abstract": "Latin America has the largest share of renewable energy for power generation in the world, but has historically been dependent on hydropower, and is vulnerable to long-term phenomena like the El Nino-Southern Oscillation (ENSO). The region is currently experiencing a steady increase in gas-based power generation along with a rapid growth in non-hydro renewables, mainly aimed at improving reliability. But exploiting complementarities between hydropower and other renewables could offer additional benefits. This paper investigates to what extent improved deployment of wind turbines and solar photovoltaic cells (PV), aimed at complementing existing hydropower, could mitigate the impacts of ENSO in Latin America. We use a meteorological reanalysis dataset to model the variations in wind-, solar- and hydropower throughout the entire 20th century and their association with different ENSO phases in the same period. A statistical algorithm is then used to identify locations at national and regional levels offering the maximal level of complementarity. The results show that adding 136 GW of wind- and solar-power with high-complementarity has the potential to cost-effectively compensate the fluctuations of hydropower and reduce the variability of renewable power not only during drought ENSO phases but also outside ENSO events. Benefits include: (i) an increase of up to 5-fold the minimum threshold of renewable power available every month, (ii) a reduction of up to 65% in the variability of renewable power generation, and (iii) reaching a levelized cost of electricity (LCOE) of 0.090.23 $/kWh, which is comparable to that of new gas plants.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1111/TGIS.12607", "year": 2020, "title": "Incorporating dynamic factors for improving a GIS-based solar radiation model", "abstract": "Solar radiation has been a major input to agricultural, hydrological, and ecological modeling. However, solar radiation is usually influenced by three groups of dynamic factors: sun\u2013earth position, terrain, and atmospheric effects. Therefore, an integrated approach to accurately consider the impacts of those dynamic factors on solar radiation is essential to estimate solar radiation over rugged terrain. In this study, a spatial and temporal gap\u2011filling algorithm was proposed to obtain a seamless daily MODIS albedo dataset. A 1 km\u2011resolution digital elevation model was used to model the impact of local topography and shading by surrounding terrain on solar radiation. A sunshine\u2011based model was adopted to simulate radiation under the influence of clouds. A GIS\u2011based solar radiation model that incorporates albedo, shading by surrounding terrain, and variations in cloudiness was used to address the spatial variability of these factors in mountainous terrain. Compared with other independent solar radiation products, our model generated a more reliable solar radiation product over rugged terrain, with an R2 of 0.88 and an RMSE of 2.55 MJ m\u22122 day\u22121. The improved solar radiation products and open source app can be used further in practice or scientific research.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.SOLENER.2022.10.038", "year": 2022, "title": "Mean-preserving interpolation with splines for solar radiation modeling", "abstract": "Interpolation is a fundamental process in solar resource assessment that glues consecutive components of the modeling chain. Most interpolation techniques assume that the interpolating function must go through the interpolation points. However, this assumption does not fit with averaged datasets or variables that must be conserved across interpolation. Here I present a mean-preserving splines method for interpolating one-dimensional data that conserves the interpolated field and is appropriate for averaged datasets. It uses second-order polynomial splines to minimize the fluctuations of the interpolated field, restricts the interpolation results to user-provided limits to prevent unphysical values, deals with periodic boundary conditions in the interpolated field, and can work with non-uniform averaging grids. The validity and performance of the method are illustrated against regular second- and third-order splines using relevant case examples in the solar resource assessment realm.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1088/1361-6382/ABD301", "year": 2021, "title": "The BepiColombo solar conjunction experiments revisited", "abstract": "BepiColombo ESA/JAXA mission is currently in its 7 year cruise phase towards Mercury. The Mercury orbiter radioscience experiment (MORE), one of the 16 experiments of the mission, will start its scientific investigation during the superior solar conjunction (SSC) in March 2021 with a test of general relativity (GR). Other solar conjunctions will follow during the cruise phase, providing several opportunities to improve the results of the first experiment. MORE radio tracking system allows to establish precise ranging and Doppler measurements almost at all solar elongation angles (up to 7-8 solar radii), thus providing an accurate measurement of the relativistic time delay and frequency shift experienced by a radio signal during an SSC. The final objective of the experiment is to place new limits to the accuracy of the GR as a theory of gravity in the weak-field limit. As in all gravity experiments, non-gravitational accelerations acting on the spacecraft are a major concern. Because of the proximity to the Sun, the spacecraft will undergo severe solar radiation pressure acceleration, and the effect of the random fluctuations of the solar irradiance may become a significant source of spacecraft buffeting. In this paper we address the problem of a realistic estimate of the outcome of the SSC experiments of BepiColombo, by including in the dynamical model the effects of random variations in the solar irradiance. We propose a numerical method to mitigate the impact of the variable solar radiation pressure on the outcome of the experiment. Our simulations show that, with different assumptions on the solar activity and observation coverage, the accuracy attainable in the estimation of \u03b3 lays in the range [6-13] \u00d710-6.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1093/PASJ/PSZ017", "year": 2019, "title": "Comparison of polarization at two lunar eclipse events", "abstract": "We present the results of imaging polarimetry of the eclipsed Moon on 2014 October 8. The observed polarization degree was less than 1% in both the V and R bands, which contrasts with the reported 2%3% polarization during the eclipse of 2015 April 4. We examined the Earths atmospheric data on the two dates and found that the high (7 km) cloud distribution was more inhomogeneous for the 2015 eclipse than it was for the 2014 eclipse. The polarization position angle observed during the 2015 eclipse can be explained if the major polarizing source was high clouds with an intermediate horizontal optical thickness. We suggest a possible dependence of the lunar eclipse polarization on the Earths high cloud distribution.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-20-10845-2020", "year": 2020, "title": "Aerosol solar radiative forcing near the Taklimakan Desert based on radiative transfer and regional meteorological simulations during the Dust Aerosol \u2026", "abstract": "Abstract. The Taklimakan Desert is a main and continuous source of Asian dust particles causing significant direct radiative effects, which are commonly quantified by the aerosol solar radiative forcing (ASRF). To improve the accuracy of estimates of dust ASRF, the Dust Aerosol Observation-Kashi (DAO-K) campaign was carried out near the Taklimakan Desert in April 2019. The objective of the DAO-K campaign is to provide crucial parameters needed for the calculation of ASRF, such as dust optical and microphysical properties, vertical distribution, and surface albedo. The ASRF was calculated using radiative transfer (RT) simulations based on the observed aerosol parameters, additionally considering the measured atmospheric profiles and diurnal variations of surface albedo. As a result, daily average values of ASRF of 19 W m2 at the top of the atmosphere and 36 W m2 at the bottom of the atmosphere were derived from the simulations conducted during the DAO-K campaign. Furthermore, the Weather Research and Forecasting model with Chemistry (WRF-Chem), with assimilation of measurements of the aerosol optical depth and particulate matter (PM) mass concentrations of particles with aerodynamic diameter smaller than 2.5 m (PM2.5) and 10 m (PM10), is employed to estimate the dust ASRF for comparison. The results of the ASRF simulations (RT and WRF-Chem) were evaluated using ground-based downward solar irradiance measurements, which have confirmed that the RT simulations are in good agreement with simultaneous observations, whereas the WRF-Chem estimations reveal obvious discrepancies with the solar irradiance measurements.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/ACP-20-10477-2020", "year": 2020, "title": "Changes in the surface broadband shortwave radiation budget during the", "abstract": "Abstract. While solar eclipses are known to greatly diminish the visible radiation reaching the surface of the Earth, less is known about the\nmagnitude of the impact. We explore both the observed and modeled levels of change in surface radiation during the eclipse of 2017. We deployed a pyranometer and Pandora spectrometer instrument to Casper, Wyoming, and Columbia, Missouri, to measure surface broadband shortwave (SW) flux and\natmospheric properties during the 21 August 2017 solar eclipse event. We\nperformed detailed radiative transfer simulations to understand the role of\nclouds in spectral and broadband solar radiation transfer in the Earth's\natmosphere for the normal (non-eclipse) spectrum and red-shift solar spectra\nfor eclipse conditions. The theoretical calculations showed that the\nnon-eclipse-to-eclipse surface flux ratio depends strongly on the\nobscuration of the solar disk and slightly on the cloud optical depth. These findings allowed us to estimate what the surface broadband SW flux would be\nfor hypothetical non-eclipse conditions from observations during the eclipse\nand further to quantify the impact of the eclipse on the surface broadband\nSW radiation budget. We found that the eclipse caused local reductions of\ntime-averaged surface flux of about 379 W m2 (50 %) and 329 W m2 (46 %) during the 3 h course of the eclipse\nat the Casper and Columbia sites, respectively. We estimated that the Moon's\nshadow caused a reduction of approximately 7 %8 % in global average surface\nbroadband SW radiation. The eclipse has a smaller impact on the absolute\nvalue of surface flux reduction for cloudy conditions than a clear\natmosphere; the impact decreases with the increase in cloud optical depth. However, the relative time-averaged reduction of local surface SW flux\nduring a solar eclipse is approximately 45 %, and it is not sensitive to cloud optical depth. The reduction of global average SW flux relative to\nclimatology is proportional to the non-eclipse and eclipse flux difference\nin the penumbra area and depends on cloud optical depth in the Moon's shadow\nand geolocation due to the change in solar zenith angle. We also discuss the influence of cloud inhomogeneity on the observed SW flux. Our results not\nonly quantify the reduction of the surface solar radiation budget, but also advance the understanding of broadband SW radiative transfer under solar\neclipse conditions.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/ASR-14-35-2017", "year": 2017, "title": "Do modelled or satellite-based estimates of surface solar irradiance accurately describe its temporal variability?", "abstract": "Abstract. This study investigates the characteristic time-scales of variability found in long-term time-series of daily means of estimates of surface solar irradiance (SSI). The study is performed at various levels to better understand the causes of variability in the SSI. First, the variability of the solar irradiance at the top of the atmosphere is scrutinized. Then, estimates of the SSI in cloud-free conditions as provided by the McClear model are dealt with, in order to reveal the influence of the clear atmosphere (aerosols, water vapour, etc.). Lastly, the role of clouds on variability is inferred by the analysis of in-situ measurements. A description of how the atmosphere affects SSI variability is thus obtained on a time-scale basis. The analysis is also performed with estimates of the SSI provided by the satellite-derived HelioClim-3 database and by two numerical weather re-analyses: ERA-Interim and MERRA2. It is found that HelioClim-3 estimates render an accurate picture of the variability found in ground measurements, not only globally, but also with respect to individual characteristic time-scales. On the contrary, the variability found in re-analyses correlates poorly with all scales of ground measurements variability.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.DIB.2018.05.031", "year": 2018, "title": "Datasets on hub-height wind speed comparisons for wind farms in California", "abstract": "This article includes the description of data information related to the research article entitled The future of wind energy in California: Future projections with the Variable-Resolution CESM[1], with reference number RENE_RENE-D-1703392. Datasets from the Variable-Resolution CESM, Det Norske Veritas Germanischer Lloyd Virtual Met, MERRA-2, CFSR, NARR, ISD surface observations, and upper air sounding observations were used for calculating and comparing hub-height wind speed at multiple major wind farms across California. Information on hub-height wind speed interpolation and power curves at each wind farm sites are also presented. All datasets, except Det Norske Veritas Germanischer Lloyd Virtual Met, are publicly available for future analysis.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ENERGY.2019.116637", "year": 2020, "title": "Assessing temporal complementarity between three variable energy sources through correlation and compromise programming", "abstract": "Renewable energies are deployed worldwide to mitigate climate change and push power systems towards sustainability. Nevertheless, the weather-dependent nature and variability of renewable energy sources often hinders their integration to national grids. The combination of different sources to profit from their beneficial complementarity has often been proposed as a partial solution to overcome these issues. This paper introduces a novel method for quantifying total temporal energetic complementarity between three different variable renewable sources, based on well-known mathematical techniques: correlation coefficients and compromise programming. It has the major advantage of allowing the simultaneous assessment of partial and total complementarity, as well as allowing for a linear assessment of complementarity. The method is employed to study the complementarity of wind, solar and hydropower generation on different temporal scales in a region of Poland. Results show that timescale selection has a determinant impact on the estimated value of the total temporal complementarity index.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2020.01.076", "year": 2020, "title": "The quest for the optimum angular-tilt of terrestrial solar panels or their angle-resolved annual insolation", "abstract": "Although solar energy is the fastest growing power technology, terrestrial solar panels typically fall behind their performance ratings established under standardised test-conditions. In particular, the angular-tilt of a panel can greatly affect its overall performance. Many studies thus aim to find the optimum tilt that maximises the annual insolation level. However, no widespread consensus has so far been found, partly because of different model assumptions applied. Here, a technique is proposed to use actual, historical solar spectra for the rigorous assessment of a panels tilt at a specific site. By combining multiple, free-accessible satellite-retrieved data products, the total all-sky insolation levels are tracked with a minutely changing global (hemispherical) solar spectrum over many years. While time-resolved annual insolation profiles can considerably vary among each other, the solar angle-resolved profile turns out to be robust to climatic conditions and is even site-independent for latitude-tilted panels. These findings can potentially unlock innovative yield optimisation methods.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JQSRT.2020.106846", "year": 2020, "title": "Comparisons of radiative transfer schemes for infrared spectra and the region with solar and infrared spectra overlap in RRTMG", "abstract": "Five radiative transfer schemes are compared in infrared spectra using the Rapid Radiative Transfer Model for General Circulation Models Applications (RRTMG). By calculating the root mean squared error of net flux (referred as RMSE(NF)) in various atmosphere, the general accuracy of these schemes ranked from low to high are: non-scattering simplification (NS), the adding method of -two-stream discrete ordinate approximation (-2DDA), -two-stream variational iteration method (-2VIM), the adding method of -four-stream discrete ordinate approximation (-4DDA) and -four-stream variational iteration method (-4VIM). And their sensitivities to cloud fraction are decreased in the same order. Furthermore, the accuracy and efficiency of these schemes other than NS are studied under the contexts of using two different methods for dealing with the region where the solar and infrared spectra overlap. As one of the two overlap methods, One Band method (OB), which is used by RRTMG, has no advantage in model efficiency and is about 0.34 (0.41) W/m2 higher in mean column RMSE(NF) of the -two-stream (-four-stream) schemes than Whole Bands method (WB). Moreover, a new scheme, which is simple but adequate to handle the overlap region, is derived to solve the solar energy in longwave spectra.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1175/JAMC-D-18-0028.1", "year": 2018, "title": "Predictability of characteristics of temporal variation in surface solar irradiance using cloud properties derived from satellite observations", "abstract": "Abstract Understanding of the characteristics of variation in surface solar irradiance on time scales shorter than several hours has been limited because ground-based observation stations are located coarsely. However, satellite observation data can be used to bridge this gap. We propose an approach for predicting characteristics of a time series of surface solar irradiance in a 121-min time window for areas without ground-based measurement systems. Time series featuresmean, standard deviation, and sample entropyare used to represent the characteristics of variation in surface solar irradiance quantitatively. We examine cloud properties over the area to design prediction models of these time series features. Cloud properties averaged over the defined domain and texture features that represent characteristics of the spatial distribution of clouds are used as measures of cloud features. Predictors for time series features, where explanatory variables are cloud features, are constructed employing the random-forest regression method. The performance test for predictions indicates that the mean and standard deviation can be predicted with higher prediction skill, whereas the predictor for sample entropy has lower prediction skill. The importance of cloud features for predictors and partial dependence of the predictors on explanatory variables are also analyzed. Cloud optical thickness (COT) and cloud fraction (CFR) were important for predicting the mean. Two texture featurescontrast and local homogeneity (LHM)and COT were important for predicting the standard deviation, and COT, LHM, and CFR were important for predicting the sample entropy. These results indicate which satellite-derived cloud field properties are useful for predicting time series features of surface solar irradiance.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1130/B35661.1", "year": 2021, "title": "The impact of weathering upon the roughness characteristics of a splay of the active fault system responsible for the massive 2016 seismic sequence of the Central \u2026", "abstract": "Fault roughness constitutes a key element in the understanding of earthquake nucleation, and surficial asperities on the fault plane play a critical role in slip dynamics and frictional behavior during the seismic cycle. Since it is not generally feasible to recover fault roughness profiles or maps directly at the seismogenic sources, faults at the Earths surface are typically used as analogues. However, these analogue fault surfaces are often subjected to weathering and erosion, which in turn, reduces their representativeness as seismogenic faults. Rupture along active faults episodically exposes fresh fault planes at the Earths surface, which represent the best available targets for the evaluation of fault roughness generated at seismogenic depths.Here we present a study conducted on a splay of the Mt. Vettore fault system in the Central Apennines, Italy, along a vertical transect that includes both a weathered and freshly exposed portion of the fault. The latter was exposed after the dramatic Mw 6.5 shock that hit the area on 30 October 2016. We have produced a highly detailed model (i.e., point cloud) of a section of the fault using structure from motion-multiview stereo photogrammetry to assess its roughness parameters (i.e., the Hurst fractal parameter) and to determine the extent to which these parameters are affected by weathering assuming that they had similar fractal characteristics when reaching the surface.Our results show that weathering can modify the value of the fractal parameters. In particular, by independently analyzing different patches of the fault, we have observed that the smoother and recently exposed portions have an average Hurst exponent of 0.52 while the average Hurst exponent of zones with more prolonged exposure times is 0.64. Accordingly, we conclude that by using high-resolution point clouds, it is possible to recognize patches of faults having a similar intensity of deterioration attributable to weathering.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0120200215", "year": 2020, "title": "Seismic Energy Release from Intra-Basin Sources along the Dead Sea Transform and Its Influence on Regional Ground Motions", "abstract": "The Dead Sea Transform (DST) dominates the seismicity of Israel and neighboring countries. Whereas the instrumental catalog of Israel (19862017) contains mainly M<5 events, the preinstrumental catalog lists 14 M 7 or stronger events on the DST, during the past two millennia. Global Positioning System measurements show that the slip deficit in northern Israel today is equivalent to M>7 earthquake. This situation highlights the possibility that a strong earthquake may strike north Israel in the near future, raising the importance of groundmotion prediction.Deep and narrow strikeslip basins accompany the DST. Here, we study ground motions produced by intrabasin seismic sources, to understand the basin effect on regional ground motions. We model seismicwave propagation in 3D, focusing on scenarios of Mw 6 earthquakes, rupturing different active branches of the DST. The geological model includes the major structures in northern Israel: the strikeslip basins along the DST, the sedimentary basins accompanying the Carmel fault zone, and the densely populated and industrialized Zevulun Valley (Haifa Bay area).We show that regional ground motions are determined by sourcepath coupling effects in the strikeslip basins, before waves propagate into the surrounding areas. In particular, ground motions are determined by the location of the rupture nucleation within the basin, the nearrupture lithology, and the basins local structure. When the rupture is located in the crystalline basement or along material bridges connecting opposite sides of the fault, ground motions behave predictably, decaying due to geometrical spreading and locally amplified atop sedimentary basins. By contrast, if rupture nucleates or propagates into shallow sedimentary units of the DST strikeslip basins, ground motions are amplified within, before propagating outside. Repeated reflections from the basin walls result in a resonant chamber effect, leading to stronger regional ground motions with prolonged durations.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.IJDRR.2022.103281", "year": 2022, "title": "Multi-objective optimization for enhancing hospital network resilience under earthquakes", "abstract": "The catastrophic earthquakes will cause numerous casualties requiring medical treatment, resulting in overcrowding in hospitals. To maintain the functionality of the hospital network, ambulance diversion (AD) between hospitals is required to relieve the stress of crowded hospitals. This research proposes a multi-objective optimization (MOO)-based emergency response model to enhance the resilience of the regional-level hospital network following earthquakes. The proposed model determines the optimal AD plan between hospitals for a given earthquake scenario. The average waiting time in the emergency department (ED) and the shortage of inpatient beds are selected as the objectives to measure the functionality of the hospital network, where the optimal solution is obtained by the Non-dominated Sorting Genetic Algorithm II (NSGA-II). The hospital network of Chengdu, China with the earthquake scenario of the Wenchuan earthquake is selected as the case study to demonstrate the validity of the proposed model. Important findings are: (1) in the optimal response plan, 66.2% of medical demands is transported to other hospitals by AD, (2) compared with the baseline situation, the average waiting time and the shortage of inpatient beds improve by 99.4% and 94.2% with the optimal emergency plan, (3) the high medical demand, low transportation efficiency, and the lack of ambulances have significant adverse impacts on the functionality of the hospital network, and (4) the proposed model is composed of high-effective coordination and a comprehensive hospital network, which avoids the waste of medical resources.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2022GL097961", "year": 2022, "title": "Icequake-Magnitude Scaling Relationship Along a Rift Within the Ross Ice", "abstract": "Fractures within ice shelves are zones of weakness, which can deform on timescales from seconds to decades. Icequakes produced during the fracturing process show a higher b-value in the Gutenberg-Richter scaling relationship than continental earthquakes. We investigate icequakes on the east side of rift WR4 in the Ross Ice Shelf, Antarctica. Our model suggests a maximum icequake slip depth that is \u223c7.8 m below the rift m\u00e9lange, where the slip area can only grow laterally along the fracture planes. We propose ductile deformation below this depth, potentially due to the saturation of unfrozen water. We use remote sensing and geodetic tools to quantify surface movement on different timescales and find that the majority of icequakes occur during falling tides. The total seismic moment is <1% of the estimated geodetic moment during a tidal cycle. This study demonstrates the feasibility of using seismology and geodesy to investigate ice rift zone rheology.", "labels": [ { "id": 5, "name": "Earthquakes" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.CSR.2021.104603", "year": 2021, "title": "Analytical solution for time-dependent shoreline position response to the tectonic recovery process in the Sendai Plain, Japan, after the 2011 Great East Japan \u2026", "abstract": "The 2011 Great East Japan Earthquake on March 11, 2011 triggered not only giant tsunami waves, but also caused significant land subsidence followed by land rise in the Sendai Coastal Plain areas. These impacts resulted in severe damages to the coastal infrastructure and induced coastal morphology changes along Japan's northeast coast. It was observed that the maximum downward deformation in the Sendai Coastal Plain was initially about - 0.3 m. Immediately after the earthquake, the land started to rise and it has already recovered back to its original position at some locations after 10 years. Thus, the high-quality measured beach profile data sets after the 2011 Tohoku Earthquake are valuable for exploring the impact of sea level rise (SLR) on shoreline position evolution, since the bed level change is inversely related to the sea level rise process. The data also provide a unique opportunity to evaluate the Equilibrium Beach Profile (EBP) theory and validate the Bruun concept. In the present study, a new simple analytical solution for time-dependent shoreline position response to the tectonic recovery process is developed based on the convolution method. The model results are able to predict the time-dependent shoreline evolution, including the maximum potential response and the characteristic erosion time scale at which the profile evolves towards a new equilibrium state.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.IJDRR.2022.103364", "year": 2022, "title": "Forecasting seismic risk within the context of the Sendai framework: An application to the Dominican Republic", "abstract": "The Sendai Framework proposes recording disaster losses from hazard events between 2015 and 2030 to monitor the progress towards reduction targets to curtail risk worldwide. In the case of earthquakes, relying on losses over 15 years is unlikely to yield sufficient evidence to support risk mitigation strategies. In this study we propose a general methodology to monitor and forecast Sendai indicators. We apply our approach to explore trajectories of probabilistic indicators of mortality (A1) and economic loss (C1) in the form of custom Sendai Indicators for the Dominican Republic. Risk reduction targets, at national and subnational level, are established and tested along with two mitigation strategies: nationwide retrofitting campaign and stronger code-enforcement. The baseline projection indicates that earthquake risk is expected to increase at a national level, with indicators A1 and C1 increasing over 17% and 27%, respectively, in a period of 35 years. At that scale, code enforcement is more effective in meeting the targets of reduced mortality by 2030 and 2050. At the sub-national level, results depend on the risk drivers in each municipality. We provide two cases: in Santiago de los Caballeros, the baseline risk projection suggests that indicators A1 and C1 will increase by more than 18% and 26% by 2050, respectively, while in Distrito Nacional they decrease by almost 5% and 3%, respectively. In the former region, code-enforcement is the most effective measure to meet the risk reduction targets, while for the latter it was found to be the retrofit campaign.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0120200360", "year": 2021, "title": "Earthquake magnitudes from dynamic strain", "abstract": "Dynamic strains have never played a role in determining local earthquake magnitudes, which are routinely set by displacement waveforms from seismic instrumentation (e.g., ML). We present a magnitude scale for local earthquakes based on broadband dynamic strain waveforms. This scale is derived from the peak rootmeansquared strains (A) in 4589 records of dynamic strain associated with 365 crustal earthquakes and 77 borehole strainmeters along the PacificNorth American plate boundary on the west coast of the United States and Canada. In this data set, catalog moment magnitudes range from 3.5Mw7.2, and hypocentral distances range from 6R500 km. The 1D representation of geometrical spreading and attenuation of A common to all strain data is logA0(R)=0.00072R1.45log(R). After correcting for instrument gain, site terms, and event terms, the magnitude scale, MDS=logAlogA0(R)log(3109), scales as 0.92Mw with a residual standard deviation of 0.19. This close association with Mw holds for events east of the 124 meridian; west of this boundary, however, a constant correction of 0.41 is needed to adjust for additional alongpath attenuation effects. As a check on the accuracy of this magnitude scale, we apply it to dynamic strain records from three strainmeters located in the near field of the 2019 M 6.4 and 7.1 Ridgecrest earthquakes. Results from these six records are in agreement to within 0.5 magnitude units, and five out of six records are in agreement to within 0.34 units.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.GEOMORPH.2020.107427", "year": 2020, "title": "Morphotectonics and Late Quaternary Seismic Stratigraphy of Lake Garda (Northern Italy)", "abstract": "Lake Garda, the largest lake in Italy at the southern front of the central Alps, provides a unique opportunity to reconstruct Quaternary geological processes related to the interplay between deglaciation driven sedimentation and tectonic activity. In fact, the topographic depression presently occupied by the lake was site of a major glacial tongue during the LGM, and is located close to the epicentral areas of two of the largest magnitude historical earthquakes recorded in the Po Plain, the Verona (Jan. 13, 1117) and Brescia, (Dec. 25, 1222) seismic events, characterized by Io IX-X MCS, respectively. Despite this peculiarity, geophysical surveys of the lake are scant. We present results of a waterborne geophysical survey of Lake Garda, leading to the acquisition of a densely-spaced grid of high-resolution seismic reflection profiles which image the lake floor and uppermost sedimentary sequence. These data enabled us to compile thematic maps which provide insights on active geologic processes in different sectors of the basin. We focused our work on a prominent seismic reflector (H1), correlated over the entire lake surface, to estimate the sediment deposition rate at the scale of the last 10 ka, and to evaluate the variability of seismic facies and geological processes in different sectors of the basin. Based on available stratigraphic data, we discuss whether H1 could mark the diachronic glacial/fluvio-glacial transition after the Last Glacial Maximum, when the ice tongues south of the Alps started to melt and collapse. We observed that sediments of the southern Lake Garda are affected by incipient tectonic deformation, and two major seismoturbidite-homogenite beds might represent over 50% of the Holocene sedimentary record in the lake depocenter, making the study of the Lake Garda stratigraphy an interesting tool for assessing earthquake hazards at the southern front of the Alpine chain.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.EPSL.2018.09.024", "year": 2018, "title": "Localised thickening and grounding of an Antarctic ice shelf from tidal triggering and sizing of cryoseismicity", "abstract": "We observe remarkably periodic patterns of seismicity rates and magnitudes at the Fimbul Ice Shelf, East Antarctica, correlating with the cycles of the ocean tide. Our analysis covers 19 years of continuous seismic recordings from Antarctic broadband stations. Seismicity commences abruptly during austral summer 2011 at a location near the ocean front in a shallow water region. Dozens of highly repetitive events occur in semi-diurnal cycles, with magnitudes and rates fluctuating steadily with the tide. In contrast to the common unpredictability of earthquake magnitudes, the event magnitudes show deterministic trends within single cycles and strong correlations with spring tides and tide height. The events occur quasi-periodically and the highly constrained event sources migrate landwards during rising tide. We show that a simple, mechanical model can explain most of the observations. Our model assumes stick-slip motion on a patch of grounded ice shelf, which is forced by the variations of the ocean-tide height and ice flow. The well fitted observations give new insights into the general process of frictional triggering of earthquakes, while providing independent evidence of variations in ice shelf thickness and grounding.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/GEOHAZARDS3030019", "year": 2022, "title": "Analysis of Faster-Than-Real-Time (FTRT) Tsunami Simulations for the Spanish Tsunami Warning System for the Atlantic", "abstract": "Real-time local tsunami warnings embody uncertainty from unknowns in the source definition within the first minutes after the tsunami generates. In general, Tsunami Warning Systems (TWS) provide a quick estimate for tsunami action from deterministic simulations of a single event. In this study, variability in tsunami source parameters has been included by running 135 tsunami simulations; besides this, four different computational domains in the northeastern Atlantic ocean have been considered, resulting in 540 simulations associated with a single event. This was done for tsunamis generated by earthquakes in the Gulf of Cadiz with impact in the western Iberian peninsula and the Canary Islands. A first answer is provided after one minute, and 7 min are required to perform all the simulations in the four computational domains. The fast computation allows alert levels all along the coast to be incorporated into the Spanish National Tsunami Early Warning System. The main findings are that the use of a set of scenarios that account for the uncertainty in source parameters can produce higher tsunami warnings in certain coastal areas than those obtained from a single deterministic reference scenario. Therefore, this work shows that considering uncertainties in tsunami source parameters helps to avoid possible tsunami warning level underestimations. Furthermore, this study demonstrates that this is possible to do in real time in an actual TWS with the use of high-performance computing resources.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/RS11192192", "year": 2019, "title": "Decreasing Trend of Geohazards Induced by the 2008 Wenchuan Earthquake Inferred from Time Series NDVI Data", "abstract": "The occurrence of aftershocks and geohazards (landslides, collapses, and debris flows) decreases with time following a major earthquake. The 12 May 2008 Wenchuan Earthquake in Sichuan, China, provides the opportunity to characterize the subsequent spatiotemporal evolution of geohazards. Following the 12 May 2008 Wenchuan Earthquake, the incidence of geohazards first increased sharply, representing a post-earthquake effect, before starting to decrease. We compared the spatial distribution of the area affected by vegetation damage (AVD) triggered by large and medium-scale geohazards (LMG). We studied the interval prior to the 12 May 2008 Wenchuan Earthquake (20012007), the co-seismic period (2008), and the post-earthquake interval (20092016) and characterized the trend of decreasing geohazards at a macro scale. In vegetated areas, geohazards often seriously damage the vegetation, resulting in pronounced contrasts with the surrounding surface in terms of color tone, texture, morphology, and Normalized Difference Vegetation Index (NDVI) which are evident in remote sensing images (RSI). In principle, it is possible to use the strong positive correlation between AVD and geohazards to determine indirectly the resulting vegetation and to monitor its spatiotemporal evolution. In this study we attempted to characterize the process of geohazard evolution in the region affected by the 12 May 2008 Wenchuan Earthquake during 20012016. Our approach was to analyze the characteristics of areas with reduced vegetation coverage caused by LMG. Our principal findings are as follows: (i) Before the Wenchuan Earthquake (during 20012007), there was no evidence for a linear increase in the number of LMG with time; thus, the geological environment was relatively stable and the geohazards were mainly induced by rainfall events. (ii) The 12 May 2008 Wenchuan Earthquake was the main cause of a surge in geohazards in 2008, with the characteristics of seismogenic faults and strong aftershocks determining the spatial distribution of geohazards. (iii) Following the 12 May 2008 Wenchuan Earthquake (during 20092016) the incidence of geohazards exhibited an oscillating pattern of attenuation, with a decreasing trend of higher-grade seismic intensity. The intensity of geohazards was related to rainfall and seismogenic faults, and also to the number, magnitude and depth of new earthquakes following the 12 May 2008 Wenchuan Earthquake. Our results provide a new perspective on the temporal pattern of attenuation of seismic geohazards, with implications for disaster prevention and mitigation and ecological restoration in the areas affected by the 12 May 2008 Wenchuan Earthquake.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.15625/0866-7187/40/3/12638", "year": 2018, "title": "Development of a Web-GIS based Decision Support System for earthquake warning service in Vietnam", "abstract": "This paper describes the development of a Decision support system (DSS) for earthquake warning service in Vietnam using Web GIS technology. The system consists of two main components: (1) an on-line database of earthquakes recorded from the national seismic network of Vietnam, and (2) a set of tools for rapid seismic hazard assessment. Using an online earthquake database, the system allows creating a shake map caused by a newly recorded earthquake. In addition, the Web GIS environment allows any user, including non-professional to get useful information about a just-occurred event and the possible impact caused by the earthquake shortly after its occurrence. A fault-source model developed for Vietnam was used as a part of the hazard calculation and mapping procedure. All information and results obtained from the system are automatically included in the earthquake bulletins, which will be disseminated national wide afterward by the Vietnam earthquake information and tsunami warning Center.The shake maps produced by the DSS in terms of both Peak Ground Acceleration and intensity values are rapidly available via the Web and can be used for emergency response, public information, loss estimation, earthquake planning, and post-earthquake engineering and scientific analyses. Application of the online decision support system in earthquake warning service can mitigate the earthquake risk and reduce the losses and damages due to earthquakes in Vietnam in future.ReferencesBoore D.M., Joyner W.B. and Fumal T.E., 1994. Estimation of Response Spectra and Peak Acceleration from Wester North American earthquakes: an interim report, USGS open file report, 94-127, Menlo Park, California, United States Geological Survey.Boore D.M. and Atkinson G.M., 2008. Ground-Motion Prediction Equations for the Average Horizontal Component of PGA, PGV, and 5%-Damped PSA at Spectral Periods between 0.01 s and 10.0 s. Earthquake Spectra, 24(1), 1-341.Bui Van Duan, Nguyen Anh Duong, 2017. The relation between fault movement potential and seismic activity of major faults in Northwestern Vietnam. Vietnam J. Earth Sci., 39, 240-255.Campbell K.W. and Bozorgnia Y., 1994. Near-Source Attenuation of Peak Horizontal Acceleration from Worldwide Accelerograms Recorded from 1957 to 1993, Proceedings, Fifth U.S. National Conference on Earthquake Engineering, Chicago, Illinois, July 10-14: V(III), 283-292.Campbell K.W. and Bozorgnia Y., 2008. NGA Ground Motion Model for the Geometric Mean Horizontal Component of PGA, PGV, PGD and 5% Damped Linear Elastic Response Spectra for Periods Ranging from 0.01 to 10s. Earthquake Spectra, 24(1), 1-341.Cauzzi C., Edwards B., Fah D., Clinton J., Wiemer S., Kastli F., Cua G. and Giardini D., 2014. On the customisation of shakemap for optimised use in Switzerland, 2014. Proceedings of the 2nd European Conference on Earthquake Engineering and Seismology, Istanbul, August 25-29, 1-10.Center for International Earth Science Information Network - CIESIN - Columbia University, 2016. Documentation for the Gridded Population of the World, Version 4 (GPWv4). Palisades NY: NASA Socioeconomic Data and Applications Center (SEDAC). http://dx.doi.org/10.7927/H4D50JX4 Accessed April 2018.Chiou B.S.-J. and Youngs R.R., 2008. An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra. Earthquake Spectra, 24(1), 1-341.Cornell, C.A., 1968. Engineering seismic risk analysis. Bull. Seis. Soc. Amer., 58(5), 1583-1606.Der Kiureghian and A. S-H. Ang, 1977. A fault rupture model for seismic risk analysis, Bull. Seim. Soc. Am., 67(4), 233-241.Douglas B.M. and Ryall A., 1977. Seismic risk in linear source regions, with application to the San Adreas fault, Bull. Seis. Soc. Amer., 67, 729-754.Marreiros, C. and Carrilho, F., 2012. The ShakeMap at the Instituto de Meteorologia. The proceedings of the 15th World Conference on Earthquake Engineering, Lisbon, Portugal September 24-28.Nguyen Le Minh, et al., 2012. The first peak ground motion attenuation relationships for North of Vietnam. Journal of Asian Earth Sciences. Doi: 10.1016/j.jseaes.2011.09.012.Nguyen Dinh Xuyen and Tran Thi My Thanh, 1999. To find a formula for computing ground acceleration in strong earthquake in Vietnam, J. Sci. of the Earth, 21, 207-213 (in Vietnamese).Pacific Earthquake Engineering Research Center, 2008. NGA model for average horizontal component of peak ground motion and response spectra. Earthquake Spectra, 24(1), 1-341.Tran V.H. and Kiyomiya O., 2012. Ground motion attenuation relationship for shallow strike-slip earthquakes in northern Vietnam based on strong motion records from Japan, Vietnam and adjacent regions, Structural Eng./Earthquake Eng., JSCE, 29, 23-39.Toro G.R., Abrahamson N.A. and Schneider J.F., 1997. Engineering Model of Strong Ground Motions from Earthquakes in the Central and Eastern United States, Seismological Research Letters, January/February.Wald D.J., Worden B.C., Quitoriano V. and Pankow K.L., 2006. ShakeMap Manual. Technical manual, users guide, and software guide.Wald D.L., Wald B. Worden and Goltz J., 2003. ShakeMap - a tool for earthquake response. U.S. Geological Survey Fact Sheet 087-03.Wells D.L. and Coppersmith K.J., 1994. New Empirical Relationships Among Magnitude, Rupture Length, Rupture Width, and Surface Displacement, Bulletin of the Seismological Society of America, 84, 974-1002.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JSEAES.2022.105466", "year": 2023, "title": "A new model for the segmentation, propagation and linkage of the Tan-Lu fault zone, East Asia", "abstract": "The Tan-Lu fault zone (TLF) is a major strike-slip fault with a long and complex history in East Asia, whose evolution provides a new perspective on the formation of large-scale faults (>1000 km long). Fault displacement analysis, geological mapping and U-Pb LA-ICP-MS dating have been performed to understand the evolution of the TLF. Along-strike displacement variation reveals that the TLF consists of two kinematically independent segments, the northern and southern TLF, with opposite long-term propagation directions. Structural and geochronological studies in the eastern Yanshan belt, located around the linkage area of the southern and northern TLF, indicate that NNE-trending sinistral strike-slip faults initiated at 167164 Ma and were reactivated at 124121 Ma. Structural analysis suggests that these early NNE-trending strike-slip faults transferred sinistral motion along the northern TLF into southward thrusting along the Yanshan belt, representing the Middle Jurassic southern termination of the northern TLF. Our studies suggest that the through-going TLF formed when the younger southward-propagating northern TLF merged with the older northward-propagating southern TLF in the Late Jurassic. A new model is thus proposed for the Mesozoic evolution of the TLF. The initiation and southward propagation of the northern TLF is interpreted to have resulted from the southward indentation of the Siberian craton into the amalgamated Central Asian Orogenic Belt and North China block. The divergent mega-splays of the northern TLF likely resulted from westward-younging formation during the clockwise rotation of northeast Asia. Coalescence of two genetically unrelated faults could be an alternative mode for large-scale fault formation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JB023583", "year": 2022, "title": "Fluid migration before and during slow earthquakes in the shallow Nankai subduction zone", "abstract": "Fluid migration in subduction zones is a key controlling factor of slow and megathrust earthquakes at plate boundaries. During the migration, seismic velocity and heterogeneous structures in its pathways may be temporarily perturbed, preferably triggering slow earthquakes. Here, we show that transient changes of seismic heterogeneity occurred 0-9 months before shallow slow earthquakes in the Nankai subduction zone, Japan, using very long-term (6-10 years) records of ambient seafloor noise. The heterogeneity changes preceding to shallow slow earthquakes were observed near the margin of the source region, while concurrent changes primarily occurred in the source region. We propose that the heterogeneity changes are attributed to dynamic fluid migration, and the difference in timings reflects the pore pressure level in the corresponding source region. When fluids are supplied to a source region under relatively low pressure, fluids are leaked out from its downdip or updip side, and slow earthquakes occur not immediately but with a time delay of at most 9 months. In the high pore pressure case, slow earthquakes occur immediately with fluid migration from the source region. This study suggests that the heterogeneous seismic structure is possibly changed by fluid migration before slow earthquakes in the Nankai subduction zone.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2020JB020263", "year": 2021, "title": "Data-Driven Two-Fault Modeling of the Mw 6.0 2008 Wells, Nevada", "abstract": "Structural fault complexity at depth affects seismic hazard, earthquake physics, and regional tectonic behavior, but constraining such complexity is challenging. We present earthquake source models of the February 21, 2008, Mw 6.0 Wells event that occurred in the Basin and Range in the western USA, suggesting the rupture of both the shallow and deep parts of a listric fault. We use a large data set including 150 local seismic waveforms from the USArray combined with high quality Interferometric Synthetic Aperture Radar and teleseismic waveforms. Rather than imposing an a priori fault geometry in the source inversions, as is often done in the literature, we use a data driven approach whereby all the faulting parameters and number of faults are determined by the data alone. We find a two fault normal faulting solution comprising: (i) a shallow (centroid depth \u223c4.6 km) sub event with Mw 5.3 and fault dip of \u223c77\u00b0; and (ii) a deeper (centroid depth \u223c8.8 km), larger Mw 6.0 sub event on a fault with shallower dip angle (\u223c41\u00b0). Our preferred two fault model is consistent with aftershocks and with the tectonics of the region. The local USArray waveforms used in the modeling are key to detect the rupture of both shallow and deep parts of the possible listric fault. The lack of such dense and uniform coverage of earthquakes in other regions on Earth may explain why the full seismic rupture of listric faults may have gone undetected in the past. Thus, earthquake slip on whole listric faults may be more common than previously thought.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1038/NCOMMS15980", "year": 2017, "title": "Dehydration of subducting slow-spread oceanic lithosphere in the Lesser Antilles", "abstract": "Subducting slabs carry water into the mantle and are a major gateway in the global geochemical water cycle. Fluid transport and release can be constrained with seismological data. Here we use joint active-source/local-earthquake seismic tomography to derive unprecedented constraints on multi-stage fluid release from subducting slow-spread oceanic lithosphere. We image the low P-wave velocity crustal layer on the slab top and show that it disappears beneath 60100 km depth, marking the depth of dehydration metamorphism and eclogitization. Clustering of seismicity at 120160 km depth suggests that the slabs mantle dehydrates beneath the volcanic arc, and may be the main source of fluids triggering arc magma generation. Lateral variations in seismic properties on the slab surface suggest that serpentinized peridotite exhumed in tectonized slow-spread crust near fracture zones may increase water transport to sub-arc depths. This results in heterogeneous water release and directly impacts earthquakes generation and mantle wedge dynamics.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S10518-019-00718-W", "year": 2019, "title": "Global occurrence and impact of small-to-medium magnitude earthquakes: a statistical analysis", "abstract": "Despite their much smaller individual contribution to the global counts of casualties and damage than their larger counterparts, earthquakes with moment magnitudes Mw in the range 4.05.5 may dominate seismic hazard and risk in areas of low overall seismicity, a statement that is particularly true for regions where anthropogenically-induced earthquakes are predominant. With the risk posed by these earthquakes causing increasing alarm in certain areas of the globe, it is of interest to determine what proportion of earthquakes in this magnitude range that occur sufficiently close to population or the built environment do actually result in damage and/or casualties. For this purpose, a global catalogue of potentially damaging eventsthat is, earthquakes deemed as potentially capable of causing damage or casualties based on a series of pre-defined criteriahas been generated and contrasted against a database of reportedly damaging small-to-medium earthquakes compiled in parallel to this work. This paper discusses the criteria and methodology followed to define such a set of potentially damaging events, from the issues inherent to earthquake catalogue compilation to the definition of criteria to establish how much potential exposure is sufficient to consider each earthquake a threat. The resulting statistics show that, on average, around 2% of all potentially-damaging shocks were actually reported as damaging, though the proportion varies significantly in time as a consequence of the impact of accessibility to data on damage and seismicity in general. Inspection of the years believed to be more complete suggests that a value of around 45% might be a more realistic figure.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S11069-022-05284-0", "year": 2022, "title": "Earthquake history of the Gokova fault zone by paleoseismologic trenching, SW Turkey", "abstract": "The Gulf of Gokova is a half-graben that is located on the southernmost part of the Aegean Extensional Region. The gulf is bounded on its north by the Gokova Fault Zone, which is an active fault zone that is composed of normal fault segments. We performed paleoseismological trenching throughout the fault zone at two sites, Keramos and Gereme sites. We have recognized two paleoearthquake horizons in Gereme trench and one paleoearthquake horizon in Keramos trench. Dating of samples by OSL and radiocarbon dating methods, and outcomes of Bayesian calculation in Oxcal, bracket the age of the older paleoevent as BCE 1099-161 and the younger event as CE 961-1574. Depending on the age bracket and written accounts in historical catalogues we compare the older paleoevent to the BCE 412-411 historical earthquake and the younger event to the CE 1493 historical earthquake. In conclusion, from this study, we have evidence for at least two surface faulting earthquakes during the Holocene, the most recent one representing the latest onshore surface rupturing event on the Gokova Fault Zone. Furthermore, depending on moment magnitude and rupture length relationships we suggest that the younger paleoearthquake event was about M = 7 according to a possible ~ 60-km-long surface rupture in at least between Kos island and Oren village.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/IJGI9070430", "year": 2020, "title": "Earthquake risk assessment for Tehran, Iran", "abstract": "The megacity of Tehran, the capital of Iran, is subjected to a high earthquake risk. Located at the central part of the AlpineHimalayan seismic belt, Tehran is surrounded by several active faults that show some M7+ historical earthquake records. The high seismic hazard in combination with a dense population distribution and several vulnerability factors mean Tehran is one of the top 20 worldwide megacities at a high earthquake risk. This article aims to prepare an assessment of the present-day earthquake risk in Tehran. First, the earthquake risk components including hazard, exposure, and vulnerability are evaluated based on some accessible GIS-based datasets (e.g., seismicity, geology, active faults, population distribution, land use, urban fabric, buildings height and occupancy, structure types, and ages, as well as the vicinity to some critical infrastructures). Then, earthquake hazard maps in terms of PGA are prepared using a probabilistic approach as well as a surface rupture width map. Exposure and vulnerability maps are also provided deterministically in terms of population density and hybrid physical vulnerability, respectively. Finally, all these components are combined in a spatial framework and an earthquake risk map is provided for Tehran.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0220160215", "year": 2017, "title": "The predictive relationship between earthquake intensity and tweets rate for real\u2010time ground\u2010motion estimation", "abstract": "The standard measure for evaluation of the immediate effects of an earthquake on people and manmade structures is intensity. Intensity estimates are widely used for emergency response, loss estimation, and distribution of public information after earthquake occurrence (Wood and Neumann, 1931; Brazee, 1976). Modern intensity assessment procedures process a variety of information sources. Those sources are primarily from two main categories: physical sensors (seismographs and accelerometers) and social sensors (witness reports). Acquiring new data sources in the second category can help to speed up the existing procedures for intensity calculations. One potentially important data source in this category is the widespread microblogging platform Twitter, ranked ninth worldwide as of January 2016 by number of active users, 320 million (Twitter, 2016). In our previous studies, empirical relationships between tweet rate and observed modified Mercalli intensity (MMI) were developed using data from the M 6.0 South Napa, California, earthquake (Napa earthquake) that occurred on 24 August 2014 (Kropivnitskaya et al., 2016). These relationships allow us to stream data from social sensors, supplementing data from other sensors to produce more accurate realtime intensity maps.In this study, we validate empirical relationships between tweet rate and observed MMI using new data sets from earthquakes that occurred in California, Japan, and Chile during MarchApril 2014. The statistical complexity of the validation test and calibration process is complicated by the fact that the Twitter data stream is limited for open public access, reducing the number of available tweets. In addition, in this analysis only spatially limited positive tweets (marked as a tweet about the earthquake) are incorporated into the analysis, further limiting the data set and restricting our study to a historical data set. In this work, the predictive relationship for California is recalibrated slightly, and a new set of relationships is estimated for Japan and Chile.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2020JB019854", "year": 2020, "title": "The lithospheric structure of the Gibraltar Arc System from wide\u2010angle seismic data", "abstract": "In continental settings, seismic failure is generally restricted to crustal depth. Crustal structure is therefore an important proxy to evaluate seismic hazard of continental fault systems. Here we present a seismic velocity model across the Gibraltar Arc System, from the Eurasian Betics Range (South Iberian margin), across offshore East Alboran and Pytheas (African margin) basins, and ending onshore in North Morocco. Our results reveal the nature and configuration of the crust supporting the coexistence of three different crustal domains: the continental crust of the Betics, the continental crust of the Pytheas Basin (south Alboran Basin) and onshore Morocco, and a distinct domain formed of magmatic arc crust under the East Alboran Basin. The magmatic arc under the East Alboran Basin is characterized by a velocity structure containing a relatively high-velocity lower crust (~7 km/s) bounded at the top and base by reflections. The lateral extension of this crust is mapped integrating a second perpendicular wide-angle seismic profile along the Eastern Alboran basin, together with basement samples, multibeam bathymetry, and a grid of deep-penetrating multichannel seismic profiles. The transition between crustal domains is currently unrelated to extensional and magmatic processes that formed the basin. The abrupt transition zones between the different crustal domains support that they are bounded by crustal-scale active fault systems that reactivate inherited structures. Seismicity in the area is constrained to upper-middle crust depths, and most earthquakes nucleate outside of the magmatic arc domain.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JB022188", "year": 2021, "title": "Repeating nontectonic seasonal stress changes and a possible triggering mechanism of the 2019 Ridgecrest earthquake sequence in California", "abstract": "Here we characterize the 13-year history of nontectonic horizontal strain anomalies across the regions surrounding Ridgecrest, CA, using cGPS data from January 2007. This time-dependent model reveals a seasonality in the nontectonic strain anomalies and the associated Coulomb stress changes of \u223c\u00b10.5-2 kPa. In the area surrounding the epicenters of the 2019 Ridgecrest earthquake sequence of July, we find that the seasonal preseismic Coulomb stress changes peaked every early summer (May and June) during the last 13 years including during June 2019, a month prior to the large events. In addition, our statistical tests confirm that more strike-slip earthquakes (Mw \u2265 2) occur during times when seasonal stress changes are increasing on right-lateral faults in comparison with times when stresses are decreasing. These results suggest that the timing of the 2019 Ridgecrest earthquakes may have been modulated by nontectonic seasonal stress changes. The dynamic source of the seasonal nontectonic strain/stress anomalies, however, remains enigmatic. We discuss a possible combination of driving forces that may be attributable for the seasonal variations in nontectonic strain/stress anomalies, which captured in cGPS measurements.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1093/GJI/GGX342", "year": 2017, "title": "Sensitivity of the International Monitoring System infrasound network to elevated sources: a western Eurasia case study", "abstract": "For the past 5 years (20102015) infrasound arrivals have been included in International Data Centre analyst-reviewed bulletins of events detected across the International Monitoring System (IMS). In western Eurasia, there are clusters of up to 268 events that consist of only infrasound arrivals (no associated seismic phases). These clusters are of unknown origin, although one in the North Sea region is associated with sonic booms from supersonic aircraft activity. IMS data for 17 North Sea events are analysed and compared with data from the Large Aperture Infrasound Array in the Netherlands to support the existence of these events and to determine common characteristics. Three other large clusters in western Eurasia are also identified and studied and show similar characteristics to the North Sea events, indicative of supersonic aircraft activity. The IMS infrasound network is shown to be particularly sensitive to sonic booms because the elevated source height reduces the anisotropy of infrasonic propagation within a stratospheric duct and allows for episodic upwind propagation. This episodic upwind propagation in addition to the prevailing downwind propagation, leads to clusters of Reviewed Event Bulletin events with constrained locations in western Eurasia region during the summer months. In the winter months, the recorded arrivals suggest that episodic upwind propagation is not as prevalent. Propagation modelling indicates that the subsequent unidirectional propagation, combined with the sparseness of the IMS network, leads to elongated lines of estimated event locations.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S11069-018-3261-8", "year": 2018, "title": "Seismic hazard and risk assessment based on Unified Scaling Law for Earthquakes: thirteen principal urban agglomerations of India", "abstract": "The deterministic seismic hazard map of India with spatially distributed peak ground acceleration was used to estimate seismic risk using two data sets of the Indian populationthe model population data set and the data set based on Indias Census 2011. Four series of the earthquake risk maps of the region based on these two population density sets were cross-compared. The discrepancy of the population data and seismic risks estimation were illuminated for the thirteen principal urban agglomerations of India. The confirmed fractal nature of earthquakes and their distribution in space implies that traditional probabilistic estimations of seismic hazard and risks of cities and urban agglomerations are usually underestimated. The evident patterns of distributed seismic activity follow the Unified Scaling Law for Earthquakes, USLE, which generalizes GutenbergRichter recurrence relation. The results of the systematic global analysis imply that the occurrence of earthquakes in a region is characterized with USLE: log10N (M, L) = A + B (5 M) + C log10L, where N(M, L)expected annual number of earthquakes of magnitude M within an area of liner size L, A determines seismic static rate, Bbalance between magnitude ranges, and Cfractal dimension of seismic loci. We apply the seismic hazard and risk assessment methodology developed recently based on USLE, pattern recognition of earthquake-prone geomorphic nodes, and neo-deterministic scenarios of destructive ground shaking. Objects of risk are individuals (1) as reported in the 2011 National Census data and (2) as predicted for 2010 by Gridded Population of the World (model GPWv3); vulnerability depends nonlinearly on population density. The resulting maps of seismic hazard and different risk estimates based on population density are cross-compared. To avoid misleading interpretations, we emphasize that risk estimates presented here for academic purposes only. In the matter of fact, they confirm that estimations addressing more realistic and practical kinds of seismic risks should involve experts in distribution of objects of risk of different vulnerability, i.e., specialists in earthquake engineering, social sciences, and economics.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JASTP.2020.105218", "year": 2020, "title": "Pre-seismic ionospheric anomalies and spatio-temporal analyses of MODIS Land surface temperature and aerosols associated with Sep, 24 2013 Pakistan \u2026", "abstract": "This study aims to investigate the behaviors of the potential earthquake precursors such as Total Electron Content (TEC), daytime/nighttime Land Surface Temperature (LST) and aerosols before and after the 2013 Mw 7.7 Awaran (Pakistan) earthquake. TEC values were obtained from Global Positioning System (GPS) measurements, and LST and aerosol values were retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Terra and Aqua satellites, respectively. In order to detect the anomalies, moving median method was used in TEC analyses and 2 (95% confidence level) interval was utilized in LST and Aerosol Optical Depth (AOD) analyses as anomaly indicator. TEC anomalies were identified 3 days (21.09.2013) and 5 days (19.09.2013) before the earthquake. In daytime/nighttime LST analyses, three regions of interest for spatial analyses were determined including epicenter, 10 km impact area around the epicenter and Modified Mercalli Intensity (MMI) 7.5 contour which was presented in the United States Geological Survey (USGS)'s shake map. Different anomalous days of LST were observed from these three regions of interest. In AOD analysis, only MMI 7.5 contour was considered due to its low spatial resolution (10 10km pixel size). The anomaly in AOD values was observed on 29.09.2013, 5 days after the earthquake. However, the abnormal behavior of AOD on 21.09.2013 was consistent with GPS-TEC anomaly. Furthermore, considering daytime/nighttime LST values on epicenter and 10 km impact area, we observed a systematic increase culminated near the earthquake event and a decrease after the earthquake. On the contrary, a systematic decrease and then increase of the AOD values were identified. The obtained results showed that TEC, LST and AOD were important potential precursors for Earthquake prediction; however, further developments on methods, data types and statistical analyses are still required.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1134/S0001433821120057", "year": 2022, "title": "A Study from Space of Anomalous Variations of Various Geophysical Fields during the Preparation of a Series of Strong Earthquakes in Italy in 2016\u20132017", "abstract": "A time series of the occurrence of thermal anomalies, aerosol optical-depth anomalies, and total electron content of the ionosphere during the preparation of strong earthquakes with magnitudes of M = 5.26.6 in Central Italy in 20162017 is revealed based on the joint analysis of various geophysical fields recorded from space. The values of temperatures of the surface, the near-surface layer of the atmosphere, and the outgoing longwave radiation detected by the AIRS instrument (Aqua satellite) are used to analyze thermal fields. Changes in the aerosol optical-depth values are investigated using the MCD19A2 product (Terra and Aqua satellites). Global ionospheric maps obtained from data of global satellite navigation systems and ground-based GPS stations located within a radius of 100 km from earthquake epicenters are used to study anomalies in the ionosphere. It is found that the first precursory changes in geophysical fields occurred in areas with radii of 200 km, the centers of which coincided with the centers of high earthquake risk zones, and were detected 1115 days before the main seismic shocks.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021EA001682", "year": 2021, "title": "Buried aseismic slip and off\u2010fault deformation on the southernmost San Andreas fault triggered by the 2010 El Mayor Cucapah earthquake revealed by UAVSAR", "abstract": "We use UAVSAR interferograms to characterize fault slip, triggered by the Mw 7.2 El Mayor-Cucapah earthquake on the 1 San Andreas Fault in the Coachella Valley providing comprehensive maps of short-term geodetic surface deformation that complement in situ measurements. Creepmeters and geological mapping of fault offsets on Durmid Hill recorded 4 and 8 mm of average triggered slip respectively on the fault, in contrast to radar views that reveal significant off-fault dextral deformation averaging 20 mm. Unlike slip in previous triggered slip events on the southernmost San Andreas fault, dextral shear in 2010 is not confined to transpressional hills in the Coachella valley. Edge detection and gradient estimation applied to the 50-m-sampled interferogram data identify the location (to 20 m) and local strike (to <4\u00b0) of secondary surface ruptures. Transverse curve fitting applied to these local detections provides local estimates of the radar-projected dextral slip and a parameter indicating the transverse width of the slip, which we equate with the depth of subsurface shear. These estimates are partially validated by fault-transverse interferogram profiles generated using the GeoGateway UAVSAR tool, and appear consistent for radar-projected slip greater than about 5 mm. An unexpected finding is that creep and triggered slip on the San Andreas fault terminate in the shallow subsurface below a surface shear zone that resists the simple expression of aseismic fault slip. We introduce the notion of a surface locking depth above which fault slip is manifest as distributed shear, and evaluate its depth as 6-27 m.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1017/S1049023X19005247", "year": 2020, "title": "Real-time impact analysis and response using a new disaster metrics: 2018 Sulawesi (Indonesia) earthquake and tsunami", "abstract": "Introduction:The Richter Scale measures the magnitude of the seismic activity for an earthquake; however, it does not quantify the humanitarian need at the point of impact. This poses a challenge for humanitarian stakeholders in decision and policy making, especially in risk reduction, response, recovery, and reconstruction. The new disaster metrics tool titled The YEW Disaster Severity Index (DSI) was developed and presented at the 2017 World Congress of Disaster and Emergency Medicine, May 2017, Toronto, Canada. It uses a median score of three for vulnerability and exposure indicators, a median score percentage of 100%, and medium YEW DSI scoring of four to five as baseline, indicating the ability to cope within local capacity. Therefore, scoring more than baseline coping capacity indicates that external assistance is needed. This special real-time report was presented at the 2nd National Pre-Hospital Care Conference and Championship, October 2018, Malaysia.Report:The aim of this analysis is to present the real-time humanitarian impact and response to the 2018 earthquake and tsunami at Donggala and Palu, Sulawesi in Indonesia using the new disaster metrics YEW DSI. Based on the earthquake (measuring 7.7 on the Richter Scale) and tsunami at Donggala, the humanitarian impact calculated on September 29, 2018 scored 7.4 High in the YEW DSI with 11 of the total 17 indicators scoring more than the baseline coping capacity. The same YEW DSI score of 7.4 was scored on the earthquake and tsunami at Palu, with 13 of the total 17 indicators scoring more than baseline ability to cope within local capacity. Impact analysis reports were sent to relevant authorities on September 30, 2018.Discussion & Conclusion:A State of Emergency was declared for a national response, which indicated an inability to cope within the local capacity, shown by the YEW DSI. The strong correlation between the earthquake magnitude, intensities, and the humanitarian impact at Donggala and Palu reported could be added into the science of knowledge in prehospital care and disaster medicine research and practice. As a conclusion, the real-time disaster response was found to be almost an exact fit with the YEW DSI indicators, demonstrating the inability to cope within the local capacity.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1093/GJI/GGZ343", "year": 2019, "title": "Shallow crustal imaging using distant, high-magnitude earthquakes", "abstract": "Global phases, viz. seismic phases that travel through the Earths core, can be used to locally image the crust by means of seismic interferometry. This method is known as Global Phase Seismic Interferometry (GloPSI). Traditionally, GloPSI retrieves low-frequency information (up to 1 Hz). Recent studies, however, suggest that there is high-frequency signal present in the coda of strong, distant earthquakes. This research quantifies the potential of these high-frequency signals, by analysing recordings of a multitude of high-magnitude earthquakes (6.4 Mw) and their coda on a selection of permanent USArray stations. Nearly half of the P, PKP and PKIKP phases are recorded with a signal-to-noise ratio of at least 5 dB at 3 Hz. To assess the viability of using the high-frequency signal, the second half of the paper highlights two case studies. First, a known sedimentary structure is imaged in Malargue, Argentina. Secondly, the method is used to reveal the structure of the Midcontinent Rift below the SPREE array in Minnesota, USA. Both studies demonstrate that structural information of the shallow crust (5 km) below the arrays can be retrieved. In particular, the interpreted thickness of the sedimentary layer below the Malargue array is in agreement with earlier studies in the same area. Being able to use global phases and direct P-phases with large epicentral distances (>80) to recover the Earths sedimentary structure suggests that GloPSI can be applied in an industrial context.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.EARSCIREV.2022.104069", "year": 2022, "title": "New Maps of Global Geological Provinces and Tectonic Plates", "abstract": "Accurate spatial models of tectonic plates and geological terranes are important for analyzing and interpreting a wide variety of geoscientific data and developing compositional and physical models of the lithosphere. We present a global compilation of active plate boundaries and geological provinces in a shapefile format with interpretive attributes (e.g., crust type, plate type, province type, last orogeny). The initial plate and province boundaries are constructed from a combination of published global and regional models that we refine using a variety of geoscientific constraints including, but not limited to, relative GPS motions, earthquakes, mapped faults, potential field characteristics, and geochronology. These new plate model show improved correlation to observed earthquake and volcano occurrences within deformation zones and microplates, compared to existing models, capturing 73 and 80% of these criteria, respectively. Deformation zones and microplates only account for 16% of Earth's surface area. We estimate 57.5% of the Earth's surface is covered by oceanic crust, which is a slight increase relative to the most recent seafloor age model. The model of last orogenies agrees well with peaks in the globally summed geochronology data. There is room for improvement in future editions of our global plate and geologic provinces model where basins, ice, or lack of geological data fidelity obscure bedrock geology, particularly in the eastern Central Asian Orogenic Belt, much of Africa, East Antarctica, and eastern Australia. Additionally, some province types-orogens, shields, and cratons that are homogenized within our global scheme-can likely be partitioned into smaller terranes with more precise geodynamic attributes. Despite some of these shortcomings, the digital maps presented here form a self-consistent data standard for adding spatial metadata to geoscientific databases. The database is available on GitHub where the geoscience community can provide updates to improve the models and their contemporaneity as new knowledge is acquired. The files are also released in formats suitable for use in Generic Mapping Tools and GoogleEarth.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1126/SCIENCE.ABD2438", "year": 2020, "title": "Global quieting of high-frequency seismic noise due to COVID-19 pandemic lockdown measures", "abstract": "Human activity causes vibrations that propagate into the ground as high-frequency seismic waves. Measures to mitigate the coronavirus disease 2019 (COVID-19) pandemic caused widespread changes in human activity, leading to a months-long reduction in seismic noise of up to 50%. The 2020 seismic noise quiet period is the longest and most prominent global anthropogenic seismic noise reduction on record. Although the reduction is strongest at surface seismometers in populated areas, this seismic quiescence extends for many kilometers radially and hundreds of meters in depth. This quiet period provides an opportunity to detect subtle signals from subsurface seismic sources that would have been concealed in noisier times and to benchmark sources of anthropogenic noise. A strong correlation between seismic noise and independent measurements of human mobility suggests that seismology provides an absolute, real-time estimate of human activities.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.5194/NHESS-21-3599-2021", "year": 2021, "title": "Variable-resolution building exposure modelling for earthquake and tsunami scenario-based risk assessment: an application case in Lima, Peru", "abstract": "Abstract. We propose the use of variable resolution boundaries based on central Voronoi tessellations (CVTs) to spatially aggregate building exposure models for risk assessment to various natural hazards. Such a framework is especially beneficial when the spatial distribution of the considered hazards presents intensity measures with contrasting footprints and spatial correlations, such as in coastal environments. This work avoids the incorrect assumption that a single intensity value from hazards with low spatial correlation (e.g. tsunami) can be considered to be representative within large-sized geo-cells for physical vulnerability assessment, without, at the same time, increasing the complexity of the overall model. We present decoupled earthquake and tsunami scenario-based risk estimates for the residential building stock of Lima (Peru). We observe that earthquake loss models for far-field subduction sources are practically insensitive to the exposure resolution. Conversely, tsunami loss models and associated uncertainties depend on the spatial correlations of the hazard intensities as well as on the resolution of the exposure models. We note that for the portfolio located in the coastal area exposed to both perils in Lima, the ground shaking dominates the losses for lower-magnitude earthquakes, whilst tsunamis cause the most damage for larger-magnitude events. For the latter, two sets of existing empirical flow depth fragility models are used, resulting in large differences in the calculated losses. This study, therefore, raises awareness about the uncertainties associated with the selection of fragility models and spatial aggregation entities for exposure modelling and loss mapping.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S12665-022-10496-5", "year": 2022, "title": "Study of 28th April, 2021 Mw 6.0 Assam earthquake in a part of eastern Himalayan foreland region, northeast India", "abstract": "The northeastern part of India is seismically very active due to the ongoing Indian Plate under-thrusting and rise of several mountain ranges. As a result, the Himalayas, Naga Hills, Shillong-Karbi Massifs, and the Assam Valley have many crustal-scale active faults. These faults often cause moderate to large earthquakes while releasing the accumulated stress associated with Plate tectonics. In this study, one such major earthquake event of Mw 6.0 occurred near the Kopili Fault and Himalayan Frontal Thrust in the eastern Himalayan foreland region on 28th April 2021. The event has been investigated to understand its seismotectonic and environmental impacts. The quake caused much damage in the epicentral area around Dhekiyajuli of Sonitpur District, Assam, India. The densely populated Guwahati and Tezpur cities of Assam have suffered damage as some parts of buildings and roads were collapsed. Moreover, a landslide near Bhairabkunda and several liquefaction incidents near Tezpur and Dhekiyajuli localities were also recorded, within 3050 km from the epicentre. It is found from NASA's GRACE-Land data that the increase in groundwater volume on the northern bank of the Brahmaputra than the previous year might be related to higher rainfall in the recharge zone around the Himalayan Frontal parts. Such groundwater conditions caused saturation of the subsurface soil and alluvium, which resulted in the formation of liquefaction during high shaking. These incidents also caused severe environmental damage. After the earthquake, the sprouting of mud water affected rice fields and nearby freshwater sources like ponds and lakes. This earthquake, along with the historical ones, reveals the vulnerability of the entire region to many natural hazards. This study provides a scope to understand the seismotectonic and environmental exposure of the eastern Himalayan foothill region.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3389/FEART.2022.995401", "year": 2022, "title": "Seasonal modulation of oceanic seismicity in the azores", "abstract": "The analysis of an 11-year (20082018) seismic catalogue of the Azores suggests the existence of secondary cyclic influences on the seismicity rate of the oceanic region, with more earthquakes observed during the summer months, from May to August, than in winter. Statistical testing based on Monte-Carlo simulations and a Jack-Knife methodology indicate that the seasonal modulation affects earthquakes with magnitudes M3.34.5, well above the magnitude of completeness. Here, we investigate the seasonal variations of earthquake rate considering both the whole Azores oceanic domain and four separate sub-regions, corresponding to four regional clusters identified by previous authors. The analysis shows that the seasonal modulation is particularly observed near the Triple Junction region between the Faial Island and the Mid-Atlantic Ridge. To identify possible mechanisms driving the seasonal modulation, we apply Singular Spectral Analysis to the seismicity rate and to time-series of plausible external triggers, in order to investigate possible common periodicities. We find significant correlations between the earthquake rate, sea level anomaly rate, GRACE satellite anomalies and ocean bottom pressure, suggesting that water load may modulate the Azores oceanic seismicity.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1002/2017TC004604", "year": 2017, "title": "Earthquake science in resilient societies", "abstract": "Earthquake science is critical in reducing vulnerability to a broad range of seismic hazards. Evidence-based studies drawing from several branches of the Earth sciences and engineering can effectively mitigate losses experienced in earthquakes. Societies that invest in this research have lower fatality rates in earthquakes and can recover more rapidly. This commentary explores the scientific pathways through which earthquake-resilient societies are developed. We highlight recent case studies of evidence-based decision making and how modern research is improving the way societies respond to earthquakes.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/IJGI11010012", "year": 2022, "title": "School Location Analysis by Integrating the Accessibility, Natural and", "abstract": "This study proposes a new model for land suitability for educational facilities based on spatial product development to determine the optimal locations for achieving education targets in West Java, Indonesia. Single-aspect approaches, such as accessibility and spatial hazard analyses, have not been widely applied in suitability assessments on the location of educational facilities. Model development was performed based on analyses of the economic value of the land and on the integration of various parameters across three main aspects: accessibility, comfort, and a multi-natural/biohazard (disaster) risk index. Based on the maps of disaster hazards, higher flood-prone areas are found to be in gentle slopes and located in large cities. Higher risks of landslides are spread throughout the study area, while higher levels of earthquake risk are predominantly in the south, close to the active faults and megathrusts present. Presently, many schools are located in very high vulnerability zones (2057 elementary, 572 junior high, 157 senior high, and 313 vocational high schools). The comfort-level map revealed 13,459 schools located in areas with very low and low comfort levels, whereas only 2377 schools are in locations of high or very high comfort levels. Based on the school accessibility map, higher levels are located in the larger cities of West Java, whereas schools with lower accessibility are documented far from these urban areas. In particular, senior high school accessibility is predominant in areas of lower accessibility levels, as there are comparatively fewer facilities available in West Java. Overall, higher levels of suitability are spread throughout West Java. These distribution results revealed an expansion of the availability of schools by area: senior high schools, 303,973.1 ha; vocational high schools, 94,170.51 ha; and junior high schools, 12,981.78 ha. Changes in elementary schools (3936.69 ha) were insignificant, as the current number of elementary schools is relatively much higher. This study represents the first to attempt to integrate these four parametersaccessibility, multi natural hazard, biohazard, comfort index, and land valueto determine potential areas for new schools to achieve educational equity targets.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1017/S1355770X19000159", "year": 2019, "title": "Natural disasters and regional development the case of earthquakes", "abstract": "We analyze the impact of earthquakes on nighttime lights at a sub-national level, i.e., on grids of different size. We argue that existing studies on the impact of natural disasters on economic development have several important limitations, both at the level of the outcome variable as well as at the level of the independent variable, e.g., the timing of an event and the measuring of its intensity. We aim to overcome these limitations by using geophysical event data on earthquakes together with satellite nighttime lights. Using panel fixed effects regressions covering the entire world for the period 19922013, we find that earthquakes reduce both light growth rates and light levels significantly. The effects persist for approximately 5 years, but we find no long-run effects. Effects are stronger the smaller the area of a unit of observation. National institutions and economic conditions are relevant moderating factors.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/RS14143413", "year": 2022, "title": "Satellite-Observed Thermal Anomalies and Deformation Patterns Associated to the 2021, Central Crete Seismic Sequence", "abstract": "Nowadays, there has been a growing interest in understanding earthquake forerunners, i.e., anomalous variations that are possibly associated with the complex process of earthquake evolution. In this context, the Robust Satellite Technique was coupled with 10 years (20122021) of daily night-time MODIS-Land Surface Temperature remote sensing data to detect thermal anomalies likely related to the 27 September 2021, strong onshore earthquake of magnitude Mw6.0 occurring near the Arkalochori village in Central Crete, Greece. Eight intense (signal-to-noise ratio > 3) and infrequent, quite extensive, and temporally persistent thermal signal transients were detected and characterized as pre-seismic anomalies, while one thermal signal transient was identified as a co-seismic effect on the day of the main tectonic event. The thermal anomalies dataset was combined with tectonic parameters of Central Crete, such as active faults and fault density, seismogenic zones and ground displacement maps produced using Sentinel-1 satellite imagery and the Interferometric Synthetic Aperture Radar technique. Regarding the thermal anomaly of 27 September, its greatest portion was observed over the footwall part of the fault where a significant subsidence up to 20 cm exists. We suggest that the thermal anomalies are possibly connected with gas release which happens due to stress changes and is controlled by the existence of tectonic lines and the density of the faults, even if alternative explanations could not be excluded.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0120200022", "year": 2020, "title": "Optimizing Earthquake Early Warning Alert Distance Strategies Using the July 2019 Mw 6.4 and Mw 7.1 Ridgecrest, California, Earthquakes", "abstract": "The ShakeAlert earthquake early warning system aims to alert people who experience modified Mercalli intensity (MMI) IV+ shaking during an earthquake using source estimates (magnitude and location) to estimate medianexpected peak ground motions with distance, then using these ground motions to determine medianexpected MMI and thus the extent of MMI IV shaking. Because median ground motions are used, even if magnitude and location are correct, there will be people outside the alert region who experience MMI IV shaking but do not receive an alert (missed alerts). We use 91,000 Did You Feel It? survey responses to the July 2019 Mw 6.4 and Mw 7.1 Ridgecrest, California, earthquakes to determine which groundmotion to intensity conversion equation (GMICE) best fits median MMI with distance. We then explore how incorporating uncertainty from the groundmotion prediction equation and the GMICE in the alert distance calculation can produce more accurate MMI IV alert regions for a desired alerting strategy (e.g., aiming to alert 95% of people who experience MMI IV+ shaking), assuming accurate source characterization. Without incorporating groundmotion uncertainties, we find MMI IV alert regions using medianexpected ground motions alert fewer than 20% of the population that experiences MMI IV+ shaking. In contrast, we find >94% of the people who experience MMI IV+ shaking can be included in the MMI IV alert region when two standard deviations of groundmotion uncertainty are included in the alert distance computation. The optimal alerting strategy depends on the false alert tolerance of the community due to the tradeoff between minimizing missed and false alerts. This is especially the case for situations like the Mw 6.4 earthquake when alerting 95% of the 5 million people who experience MMI IV+ also results in alerting 14 million people who experience shaking below this level and do not need to take protective action.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JB021716", "year": 2021, "title": "Unsupervised Deep Clustering of Seismic Data: Monitoring the Ross Ice", "abstract": "Advances in machine learning (ML) techniques and computational capacity have yielded state-of-the-art methodologies for processing, sorting, and analyzing large seismic data sets. In this study, we consider an application of ML for automatically identifying dominant types of impulsive seismicity contained in observations from a 34-station broadband seismic array deployed on the Ross Ice Shelf (RIS), Antarctica from 2014 to 2017. The RIS seismic data contain signals and noise generated by many glaciological processes that are useful for monitoring the integrity and dynamics of ice shelves. Deep clustering was employed to efficiently investigate these signals. Deep clustering automatically groups signals into hypothetical classes without the need for manual labeling, allowing for the comparison of their signal characteristics and spatial and temporal distribution with potential source mechanisms. The method uses spectrograms as input and encodes their salient features into a lower-dimensional latent representation using an autoencoder, a type of deep neural network. For comparison, two clustering methods are applied to the latent data: a Gaussian mixture model (GMM) and deep embedded clustering (DEC). Eight classes of dominant seismic signals were identified and compared with environmental data such as temperature, wind speed, tides, and sea ice concentration. The greatest seismicity levels occurred at the RIS front during the 2016 El Ni\u00f1o summer, and near grounding zones near the front throughout the deployment. We demonstrate the spatial and temporal association of certain classes of seismicity with seasonal changes at the RIS front, and with tidally driven seismicity at Roosevelt Island.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0220200435", "year": 2021, "title": "The modern Swedish national seismic network: two decades of intraplate microseismic observation", "abstract": "The Swedish National Seismic Network (SNSN) was modernized and rapidly expanded during the period 19982012. The network currently operates 68 permanent seismic stations, all with broadband instruments supplying realtime continuous data at 100 samples per second. Continuous data from 10 stations are shared with the international community via Orfeus, and approximately 10 stations of their individual choice are shared with institutes in neighboring countries (Denmark, Finland, Norway, and Germany). The SNSN uses the South Iceland Lowland (SIL) system as the primary system for automatic detection and event definition. In addition, an inhouse system based on migration and stacking is used for automatic detection of small events, and implementations of SeisComP (SC) and Earthworm are used primarily for rapid detection of larger regional events. Global monitoring is performed with SC, using approximately 250 global stations, and we operate a continuous rapid risk assessment system serving Swedish crisis management authorities. Since the start of automatic processing in August 2000, the SNSN has recorded and interactively analyzed more than 171,000 seismic events, of which 10,700 were earthquakes with local magnitudes ranging from around 1 to 4.3. The microearthquake activity detected in the last 20 yr has significantly improved the identification and understanding of seismically active structures in Sweden.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0220190378", "year": 2020, "title": "Cascading Partial Rupture of the Flores Thrust during the 2018 Lombok Earthquake Sequence, Indonesia", "abstract": "A series of four Mw>6 earthquakes struck the northern region of Lombok, eastern Indonesia, in a span of three weeks from late July to midAugust 2018. The series was thought to be associated with the Flores thrust, but the exact mechanism causing the unusual earthquake series has remained elusive. Our Interferometric Synthetic Aperture Radar analysis, combined with insights from seismology, indicates that the events originated at different hypocenter depths with differing fault geometries, which may explain the cascading behavior of the events, and indicates that better imaging of active fault geometry might provide some insight into future rupture behavior on other similar thrust systems. Our static stress change calculations suggest that the earlier events in the sequence played a role in promoting the later events. In addition, the second event brought the most significant impact on a nearby volcano, by causing volumetric expansion at its shallow magma plumbing system and unclamping its magma ascent zone, which may potentially have an impact on its future eruptive activity. However, no volcanic activity has so far occurred after the earthquakes. Finally, our damage proxy maps suggest that the second event caused the greatest damage to buildings.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1193/022618EQS046M", "year": 2019, "title": "Predicting fatality rates due to earthquakes accounting for community vulnerability", "abstract": "The existing prediction models for earthquake fatalities usually require a detailed building inventory that might not be readily available. In addition, existing models tend to overlook the socioeconomic characteristics of communities of interest as well as zero-fatality data points. This paper presents a methodology that develops a probabilistic zero-inflated beta regression model to predict earthquake fatality rates given the geographic distributions of earthquake intensities with data reflecting community vulnerability. As an illustration, the prediction model is calibrated using fatality data from 61 earthquakes affecting Taiwan from 1999 to 2016, as well as information on the socioeconomic and environmental characteristics of the affected communities. Using a local seismic hazard map, the calibrated prediction model is used in a seismic risk analysis for Taiwan that predicts the expected fatality rates and counts caused by earthquakes in future years.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/978-3-319-71565-0_10", "year": 2017, "title": "Real-time earthquake intensity estimation using streaming data analysis of social and physical sensors", "abstract": "Earthquake intensity is one of the key components of the decision-making process for disaster response and emergency services. Accurate and rapid intensity calculations can help to reduce total loss and the number of casualties after an earthquake. Modern intensity assessment procedures handle a variety of information sources, which can be divided into two main categories. The first type of data is that derived from physical sensors, such as seismographs and accelerometers, while the second type consists of data obtained from social sensors, such as witness observations of the consequences of the earthquake itself. Estimation approaches using additional data sources or that combine sources from both data types tend to increase intensity uncertainty due to human factors and inadequate procedures for temporal and spatial estimation, resulting in precision errors in both time and space. Here we present a processing approach for the real-time analysis of streams of data from both source types. The physical sensor data is acquired from the U.S. Geological Survey (USGS) seismic network in California and the social sensor data is based on Twitter user observations. First, empirical relationships between tweet rate and observed Modified Mercalli Intensity (MMI) are developed using data from the M6.0 South Napa, CAF earthquake that occurred on August 24, 2014. Second, the streams of both data types are analyzed together in simulated real-time to produce one intensity map. The second implementation is based on IBM Info-Sphere Streams, a cloud platform for real-time analytics of big data. To handle large processing workloads for data from various sources, it is deployed and run on a cloud-based cluster of virtual machines. We compare the quality and evolution of intensity maps from different data sources over 10-min time intervals immediately following the earthquake. Results from the joint analysis shows that it provides more complete coverage, with better accuracy and higher resolution over a larger area than either data source alone.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/RS14010135", "year": 2021, "title": "Dynamic Relationship Study between the Observed Seismicity and", "abstract": "The Palghar region (north Maharashtra, India), located in the northwestern part of the stable continental region of India, experienced a low magnitude earthquake swarm, which was initiated in September 2018 and is continuing to date (as of October 2021). From December 2018 to December 2020, ~5000 earthquakes with magnitudes from M1.2 to M3.8 occurred in a small region of 20 10 km2. These earthquakes were probably triggered by fluid migration during seasonal rainfall. In this study, we have used multi-temporal Landsat satellite data of the year 2000, 2015, 2018, 2019, and 2020, extracted lineaments, and studied the changes in frequency and pattern of lineaments before and after the initiation of the swarm in the Palghar region. An increase in the lineament density and amount of rainfall are found to be associated with the increasing frequency of earthquakes.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2020GC009477", "year": 2021, "title": "Filling the Gap in Cascadia: The Emergence of Low\u2010Amplitude Long\u2010Term Slow Slip", "abstract": "Long term slow slip events have been observed at several subduction zones around the globe, where they play an integral part in strain release along megathrust faults. Nevertheless, evidence for long term slow slip has remained elusive in the Cascadia subduction zone. Here we conduct a systematic analysis of 13 years of GNSS time series data from 2006 to 2019 and present evidence of at least one low amplitude long term slow slip event on the Cascadia subduction zone, with the possibility of others that are less resolved. Starting in mid 2012, a 1.5 year transient is observed in southern Cascadia, with a group of coastal GNSS stations moving \u223c2 mm to the west. The data are modeled as a Mw 6.4 slow slip event occurring at 15-35 km depth on the plate interface, just updip of previously recognized short term slow slip and tremor. The event shares many characteristics with similar long term transient events on the Nankai subduction zone. However, the total fault slip amplitude is an order of magnitude smaller in Cascadia when compared to large events elsewhere, making long term slow slip detection challenging in Cascadia. While there are other westward long duration transients in the refined data set, the surface displacements are below the level of the noise or are limited spatially to a few neighboring stations, making interpretation unclear.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021EF002515", "year": 2022, "title": "How low should we alert? Quantifying intensity threshold alerting strategies for earthquake early warning in the United States", "abstract": "We use a suite of historical earthquakes to quantitatively determine earthquake early warning (EEW) alert threshold strategies for a range of shaking intensity targets for EEW along the United States West Coast. The current method for calculating alert regions for the ShakeAlert EEW System does not take into account variabilities and uncertainties in shaking distribution. As a result, if the modified Mercalli intensity (MMI) level used to determine the extent of the alert region (the alert threshold) is the same as the target intensity threshold, the alert region will be too small to include all locations that require alerts even if earthquake source parameters are estimated accurately. Missed alerts can be reduced by using a lower alert threshold than the target threshold. This expands the alert region, increasing the number of precautionary alerts issued to people who experience shaking below the target level. We determine alert thresholds that optimize this tradeoff between missed and precautionary alerts for target thresholds of MMI 4.0-6.0 using 143 M5.0-7.3 earthquake ShakeMaps as ground truth. We examine the quality of each alerting strategy relative to the target MMI, where we define alert quality metrics in terms of both the area and population alerted. Optimal alert thresholds maximize correct alerts while limiting most precautionary alerts to regions that are likely to still feel some shaking. We find these optimal alert thresholds also maximize warning times. This analysis presents a quantitative framework ShakeAlert can use to communicate alerting strategies and performance expectations to ShakeAlert users.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1093/GJI/GGAB232", "year": 2021, "title": "Maximum covariance direction method for unconventional seismic sources", "abstract": "We propose a new array covariance matrix analysis method, named maximum covariance direction method (MCD method), to detect and locate unconventional seismic sources of weak signals without clear onsets. The MCD method builds a normalized-covariance matrix of time-shifted seismic waveforms recorded in a seismic array and determines the existence of source based on the consistency of the maximum covariance direction with the theoretical prediction. Synthetic tests demonstrate effectiveness of the MCD method in detecting one and multiple isolated sources with low signal-to-noise ratios. As a data application, we study 1-hr long-period tremors (LPTs) around Aso Volcano of Japan in 2014 November 24. A total of 26 LPTs are detected near the Naka-dake first crater of Aso Volcano, with the uncertainties of source location of about 7 km. Using the recorded background noise at the seismic stations, we show that the MCD method can detect LPTs even when the LPT signals are buried in the background noise and become indiscernible in the seismic data. Unlike traditional methods that employ the coherent features of seismic signals for source detection, the MCD method places emphases on both the coherence of seismic signals and consistency of the direction of the coherent signals from a potential source location. The synthetic tests and data application indicate that the MCD method provides a good alternative to other traditional methods for detecting and locating unconventional seismic sources, with a major improvement of avoiding source misidentification in the presence of strong incoherent signals.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1038/S41598-019-49008-0", "year": 2019, "title": "The Spatial and Temporal Influence of Cloud Cover on Satellite-Based Emergency Mapping of Earthquake Disasters", "abstract": "The ability to rapidly access optical satellite imagery is now an intrinsic component of managing the disaster response that follows a major earthquake. These images provide synoptic data on the impacts, extent, and intensity of damage, which is essential for mitigating further losses by feeding into the response coordination. However, whilst the efficiency of the response can be hampered when cloud cover limits image availability, spatio-temporal variations in cloud cover have never been considered as part of the design of effective disaster mapping. Here we show how annual variations in cloud cover may affect our capacity to respond rapidly throughout the year and consequently contribute to overall earthquake risk. We find that on a global scale when accounting for cloud, the worst time of year for an earthquake disaster is between June and August. During these months, 40% of the global population at risk from earthquakes are obscured from optical satellite view for >3 consecutive days. Southeastern Asia is particularly strongly affected, accounting for the majority of the population at risk from earthquakes that could be obscured by cloud in every month. Our results demonstrate the importance of the timing of earthquakes in terms of our capacity to respond effectively, highlighting the need for more intelligent design of disaster response that is not overly reliant on optical satellite imagery.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2018GL078126", "year": 2019, "title": "A Possible Second Large Subglacial Impact Crater in Northwest Greenland", "abstract": "Following the discovery of the Hiawatha impact crater beneath the northwest margin of the Greenland Ice Sheet, we explored satellite and aerogeophysical data in search of additional such craters. Here we report the discovery of a possible second subglacial impact crater that is 36.5-km wide and 183 km southeast of the Hiawatha impact crater. Although buried by 2 km of ice, the structure's rim induces a conspicuously circular surface expression, it possesses a central uplift, and it causes a negative gravity anomaly. The existence of two closely spaced and similarly sized complex craters raises the possibility that they formed during related impact events. However, the second structure's morphology is shallower, its overlying ice is conformal and older, and such an event can be explained by chance. We conclude that the identified structure is very likely an impact crater, but it is unlikely to be a twin of the Hiawatha impact crater.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SCS.2020.102488", "year": 2020, "title": "Assessing the spatiotemporal variation in anthropogenic heat and its impact on the surface thermal environment over global land areas", "abstract": "Anthropogenic heat that is mainly released in cities is rapidly rising in the context of global warming, while its impact on the land surface thermal environment is not completely clear. This study compared the anthropogenic heat flux (AHF) with the surface net solar radiation (SNSR) and analyzed the relationship between AHF and the surface urban heat island effect (ESUHI) on the basis of the estimation and analysis of global terrestrial AHF. Results indicated that the global-averaged terrestrial AHF caused by energy consumption and human metabolism increased from 0.07 to 0.15 W/m2 from 1980 to 2018. While a decrease in AHF mainly occurred in the developed cities of Europe and the United States, developing cities, particularly in eastern China, experienced an increase in AHF. The averaged terrestrial AHFs were far less than the corresponding SNSRs at the global and continental scales, whereas they were generally comparable in urban areas. AHF in the 100 largest cities around the globe was 19.56 (6.54) W/m2 in 2018 (1980) on average, which was approximately 12% (4%) of the corresponding SNSR. Additionally, we found a significantly positive correlation between AHF and ESUHI in eastern China (R2 = 0.8383, P < 0.01). These findings imply that anthropogenic heat has a considerable impact on the land surface thermal environment and is one of the most important contributors to dramatic urban warming, which needs to be considered in future climate-related policy formulation and evaluation.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCS.2021.103263", "year": 2021, "title": "The case of Tehran's urban heat island, Iran: Impacts of urban 'lockdown'associated with the COVID-19 pandemic", "abstract": "The increasing expansion of urban environments with associated transformation of land-cover has led to the formation of urban heat islands (UHI) in many urbanized regions worldwide. COVID-19 related environmental impacts, through reduced urban activities, is worthy of investigation as it may demonstrate human capacity to manage UHI. We aim to establish the thermal impacts associated with COVID-19 induced urban lockdown from 20 March to 20 April 2020 over Tehran. Areal changes in UHI are assessed through Classification and Regression Trees (CART), measured against background synoptic scale temperature changes over the years 19502020. Results indicate that monthly Tmean, Tmax and Tmin values during this time were considerably lower than long-term mean values for the reference period. Although the COVID-19 initiated shutdown led to an identifiable temperature anomaly, we demonstrate that this is not a product of upper atmospheric or synoptic conditions alone. We also show that the cooling effect over Tehran was not spatially uniform, which is likely due to the complexity of land uses such as industrial as opposed to residential. Our findings provide potentially valuable insights and implications for future management of urban heat islands during extreme heat waves that pose a serious threat to human health.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1088/1748-9326/AB28B0", "year": 2019, "title": "Interacting implications of climate change, population dynamics, and", "abstract": "Abstract\r\n One near-term expression of climate change is increased occurrence and intensity of extreme heat events. The evolution of extreme heat risk in cities depends on the interactions of large-scale climate change with regional dynamics and urban micro-climates as well as the distribution and demographic characteristics of people who live and work within these micro-climate areas. Here we use California as a testbed where we employ a suite of high-resolution (1.5 km) future regional climate simulations coupled with a satellite-driven urban canopy model and a spatially explicit population projection to investigate the interacting effects of climate change, population growth, and urban heat mitigation measures, such as cool roofs, on exposure to extreme heat events. We find that climate change and population growth reinforce with one another to drive substantial increases in future exposure to heat extremes, which are poised to become more frequent, longer, and more intense. Exposure to events analogous to historic high-mortality extreme heat waves increases by 3.56 folds. Widespread implementation of cool roofs can offset a substantial fraction (51%100%) of the increased heat exposure and associated building energy demand owing to climate change in urbanized regions.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.CITIES.2022.103705", "year": 2022, "title": "Are global cities homogenizing? An assessment of urban form and heat island implications", "abstract": "The rapid growth of citiesalong with the increasing connectedness of the world's social, economic, and political systemshas been hypothesized to generate a homogenization of urban form and associated environmental impacts. These hypotheses, however, have rarely been tested. Employing satellite imagery of 150 of the most populous cities in China, India, and the United States, we examine how the area and configuration of built-up land within cities has changed between 1995 and 2015 and assess impacts on the urban heat island effect. We find similar urban form trends across the three countries. The strongest evidence of homogenization is in the connectivity of urban form, while the shape of cities is linked to higher daytime surface urban heat island (SUHI) intensity. In the context of this and other research, we postulate that the identified urban form trends may lead to the homogenization of the biotic and abiotic environment of cities. Homogenization presents an opportunity for cities to learn from each other as they encounter similar ecological outcomes driven, in part, by their increasingly similar urban form.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1002/QJ.3874", "year": 2020, "title": "How an urban parameterization affects a highresolution global climate simulation", "abstract": "The impact of urban areas on the global and regional climate has been assessed using the global Conformal Cubic Atmospheric Model (CCAM) including an urban canyon parameterization at a global resolution of 50 km. Simulations were produced with and without urban areas to assess urban impacts for the historical period 1980-2000. Two different land cover and urban datasets (one based on IGBP-DIS, the other on MODIS) were tested. In addition, simulations were performed for the end of the 21st century with the RCP8.5 scenario. Evaluation of the historical climate simulations indicates realistic local urban effects, such as higher daily minimum air temperatures (tasmin), higher sensible heat flux and lower latent heat flux at urban grid cells. In regions with large fractions of urban areas, some regional changes are also noted. In addition, there are significant regional effects far away from the main urban areas, which are similar in magnitude to the effects of the different non-urban land cover input datasets. Under the projected warming at the end of the 21st century (with no land cover change), there is a decrease in anthropogenic heating, primarily during wintertime. There is a slightly smaller increase in daily maximum temperature and a slightly larger increase in tasmin in urban areas compared to rural areas. This leads to a smaller increase in the diurnal temperature range within urban areas. The tasmin changes also imply an increase in the urban heat island effect for larger cities. The results of this sensitivity study show that there is a detectable impact of urban areas on high-resolution global climate simulations. Consequently, there is a need to include urban areas in global simulations, as well as in studies of land-use change.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1088/1748-9326/AC47C3", "year": 2022, "title": "Lack of vegetation exacerbates exposure to dangerous heat in dense settlements in a tropical African city", "abstract": "Abstract\r\n \r\n Both climate change and rapid urbanization accelerate exposure to heat in the city of Kampala, Uganda. From a network of low-cost temperature and humidity sensors, operational in 20182019, we derive the daily mean, minimum and maximum Humidex in order to quantify and explain intra-urban heat stress variation. This temperature-humidity index is shown to be heterogeneously distributed over the city, with a daily mean intra-urban Humidex Index deviation of 1.2\r\n \r\n C on average. The largest difference between the coolest and the warmest station occurs between 16:00 and 17:00 local time. Averaged over the whole observation period, this daily maximum difference is 6.4\r\n \r\n C between the warmest and coolest stations, and reaches 14.5\r\n \r\n C on the most extreme day. This heat stress heterogeneity also translates to the occurrence of extreme heat, shown in other parts of the world to put local populations at risk of great discomfort or health danger. One station in a dense settlement reports a daily maximum Humidex Index of\r\n \r\n \r\n \r\n \r\n \r\n >\r\n \r\n \r\n \r\n 40 \r\n \r\n C in 68% of the observation days, a level which was never reached at the nearby campus of the Makerere University, and only a few times at the city outskirts. Large intra-urban heat stress differences are explained by satellite earth observation products. Normalized Difference Vegetation Index has the highest (75%) power to predict the intra-urban variations in daily mean heat stress, but strong collinearity is found with other variables like impervious surface fraction and population density. Our results have implications for urban planning on the one hand, highlighting the importance of urban greening, and risk management on the other hand, recommending the use of a temperature-humidity index and accounting for large intra-urban heat stress variations and heat-prone districts in urban heat action plans for tropical humid cities.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.21926/AEER.2202022", "year": 2022, "title": "How the Interaction of Heatwaves and Urban Heat Islands Amplify Urban Warming", "abstract": "An increase in global temperature will likely result in more intense and frequent heatwaves that would last longer. Simultaneously, the growth of urban population requires more areas of land incorporated into urbanization, because most people are expected to live in cities, which will increase the intensity and duration of urban heat islands. However, the extent of the link between global warming induced heatwaves and urbanization caused heat islands is barely understood. Understanding the link would give a new information about catastrophic heat mitigation strategies. This paper, therefore, quantifies, at the sub-continental scale of Eastern North America, the effects of background perturbations by the synergies between heatwaves and urban heat islands using simulations from the Weather Research and Forecasting (WRF) model, and focusing on the responses of urban energy balances, boundary layer height and vertical profiles of heat, momentum and moisture. Results showed that urban heat islands exacerbate heatwaves by deepening the turbulent boundary layer height, modifying the urban surface energy and regional winds. The fractional energy shift from latent to sensible heat fluxes and the consequent changes to the urban planetary boundary layer tends to amplify the intensity, extent and duration of extensive heatwaves. The response of ground heat fluxes to urban surfaces lags, while urban canopy humidity dissipates earlier because at the onset of the heatwave the surface water evaporates quickly to the point where there is less water left for evaporation leaving the urbanized regions vulnerable to more heating. During the heatwave event, the mean wind speed dropped by 2.5 m/s, hence less cool air is available for ventilation. The planetary boundary layer deepens by a maximum of 90-m over urban compared to rural and this may prolong urban surface heating. Based on the results, it can be concluded that the best heat-stress management strategies from the perspectives of urban energy balance and planetary boundary layer height is an integral approach that would lower sensible heat fluxes and increase surface albedo, latent heat fluxes and wind flows towards urban centers.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1088/1748-9326/AB3B99", "year": 2019, "title": "Disproportionately higher exposure to urban heat in lower-income neighborhoods: a multi-city perspective", "abstract": "Abstract\r\n A growing literature documents the effects of heat stress on premature mortality and other adverse health outcomes. Urban heat islands (UHI) can exacerbate these adverse impacts in cities by amplifying heat exposure during the day and inhibiting the bodys ability to recover at night. Since the UHI intensity varies not only across, but also within cities, intra-city variation may lead to differential impact of urban heat stress on different demographic groups. To examine these differential impacts, we combine satellite observations with census data to evaluate the relationship between distributions of both UHI and income at the neighborhood scale for 25 cities around the world. We find that in most (72%) cases, poorer neighborhoods experience elevated heat exposure, an incidental consequence of the intra-city distribution of income in cities. This finding suggests that policymakers should consider designing city-specific UHI reduction strategies to mitigate its impacts on the most socioeconomically vulnerable populations who may be less equipped to adapt to environmental stressors. Since the strongest contributor of intra-urban UHI variability among the physical characteristics considered in this study is a neighborhoods vegetation density, increasing green space in lower income neighborhoods is one strategy urban policymakers can adopt to ameliorate some of UHIs inequitable burden on economically disadvantaged residents.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1080/23789689.2020.1773013", "year": 2020, "title": "Urban heat implications from parking, roads, and cars: A case study of metro Phoenix", "abstract": "To understand the transportation sectors role on influencing and mitigating heat in cities, this research quantifies added heat from pavement infrastructure and vehicle travel in the hot and automobile dependent metropolitan Phoenix, Arizona. Construction of a one-dimensional heat transfer model for local weather conditions and pavement design is combined with vehicle travel densities to simulate spatiotemporal sensible heat flux magnitudes. In metro Phoenix, sensible heat from pavements and vehicles is comprised of 67% from roadways, 29% from parking, and 3.9% vehicles. Concrete and asphalt pavement emit 15% and 37% more sensible heat compared to the bare ground, respectively. Added sensible heat from pavement peaks during summer afternoons when heat emissions relative to the ground are 26% and 46% greater for concrete and asphalt. Results indicate pavement infrastructure contributes significantly to Phoenixs urban heat balance, and areas surrounding busy vehicle corridors may be undesirable for outdoor activities during summer rush hours.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.15551/PESD2020142001", "year": 2020, "title": "SUMMER URBAN HEAT ISLAND OF GALATI CITY (ROMANIA) DETECTED USING SATELLITE PRODUCTS", "abstract": "The paper presents the main features of the urban heat island of Galati city during the summer season for a period of 16 years (2003-2018) using MODIS products. The main objectives were to analyse the extension and geometry of the urban heat island (UHI), its intensity, as well as its connection with land cover. The study is based on LST (Land Surface Temperature), a product obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) sensors located on board of the Terra (EOS AM-1) satellite since 2001 and Aqua (EOS PM-1) satellite since 2003. The boundaries, geometry and spatial extent of the UHI were delimited primarily through the Rodionov test. Through this method, the changing points along four transects over Galati city were identified (North-South, East-West, Northeast-Southwest and Northwest-Southeast) and have been used to delimitate the UHI. Overall, the Galati UHI assessed by satellite information is stronger during the day when the UHI is split in two centres, developed over the industrial area in the west and over the residential part of the town in the east, while during the night the UHI is weaker being developed more clearly over the oldest part of the city. One of the major characteristics of the Galati UHI is that it is highly influenced by the water bodies encircling the city. During the day the intensity of UHI reaches 2-2.5C while during the night decreases below 2.0C. The relation of the UHI with land cover and the attenuation of UHI in the surrounding area are also investigated.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1073/PNAS.2024792118", "year": 2021, "title": "Global urban population exposure to extreme heat", "abstract": "Significance\r\n Increased extreme heat exposure from both climate change and the urban heat island effect threatens rapidly growing urban settlements worldwide. Yet, because we do not know where urban population growth and extreme heat intersect, we have limited capacity to reduce the impacts of urban extreme heat exposure. Here, we leverage fine-resolution temperature and population data to measure urban extreme heat exposure for 13,115 cities from 1983 to 2016. Globally, urban exposure increased nearly 200%, affecting 1.7 billion people. Total urban warming elevated exposure rates 52% above population growth alone. However, spatially heterogeneous exposure patterns highlight an urgent need for locally tailored adaptations and early warning systems to reduce harm from urban extreme heat exposure across the planets diverse urban settlements.\r\n , \r\n \r\n Increased exposure to extreme heat from both climate change and the urban heat island effecttotal urban warmingthreatens the sustainability of rapidly growing urban settlements worldwide. Extreme heat exposure is highly unequal and severely impacts the urban poor. While previous studies have quantified global exposure to extreme heat, the lack of a globally accurate, fine-resolution temporal analysis of urban exposure crucially limits our ability to deploy adaptations. Here, we estimate daily urban population exposure to extreme heat for 13,115 urban settlements from 1983 to 2016. We harmonize global, fine-resolution (0.05), daily temperature maxima and relative humidity estimates with geolocated and longitudinal global urban population data. We measure the average annual rate of increase in exposure (person-days/year\r\n 1\r\n ) at the global, regional, national, and municipality levels, separating the contribution to exposure trajectories from urban population growth versus total urban warming. Using a daily maximum wet bulb globe temperature threshold of 30 C, global exposure increased nearly 200% from 1983 to 2016. Total urban warming elevated the annual increase in exposure by 52% compared to urban population growth alone. Exposure trajectories increased for 46% of urban settlements, which together in 2016 comprised 23% of the planets population (1.7 billion people). However, how total urban warming and population growth drove exposure trajectories is spatially heterogeneous. This study reinforces the importance of employing multiple extreme heat exposure metrics to identify local patterns and compare exposure trends across geographies. Our results suggest that previous research underestimates extreme heat exposure, highlighting the urgency for targeted adaptations and early warning systems to reduce harm from urban extreme heat exposure.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1177/0739456X19879214", "year": 2019, "title": "Urban Heat Management in Louisville, Kentucky: A Framework for Climate Adaptation Planning", "abstract": "We explore the potential for cities to develop urban heat management plans to moderate rising temperatures and to lessen the impact of extreme heat on human health. Specifically, we model the impacts of heat management strategies, including tree planting and other green infrastructure, cool roofing and paving, and a reduction in waste heat emissions from buildings and vehicles, on estimated heat-related mortality across Louisville, Kentucky. Our assessment finds a combination of urban heat management strategies to lessen summer temperatures by as much as 10F on hot days and to reduce estimated heat-related mortality by more than 20 percent.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCS.2018.04.033", "year": 2018, "title": "Urban heat island in current and future climates for the island of Montreal", "abstract": "Urban regions with their distinct surface characteristics modify energy and water partitioning, leading to higher temperatures in comparison to the adjoining non-urban regions. This phenomenon, referred to as the Urban Heat Island (UHI), is studied for the island of Montreal situated in central-eastern Canada in the province of Quebec, for current and future climates, for the summer and fall seasons. Projected changes to the UHI for the region are studied using offline high-resolution (250 m) simulations performed with a land surface scheme, the Canadian Land Surface Scheme (CLASS), with and without the urban representation from the Town Energy Balance (TEB) model, for the RCP 8.5 scenario. Projected changes to land surface and 2 m air temperature fields suggest significant increases for both urban and nonurban regions, with small increases in the UHI intensity. The small increases in UHI intensity are due to the slightly higher increase in urban surface temperatures compared with nonurban regions, associated with increase and decrease in sensible and latent heat fluxes, respectively, for the urban regions. Furthermore, analysis of the projected changes to the number of hot days suggests significant increases, with urban regions augmenting the increases by 58 days in summer and 25 days in fall.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.APGEOG.2021.102533", "year": 2021, "title": "Diurnal and seasonal trends and associated determinants of surface urban heat islands in large Bangladesh cities", "abstract": "Many surface urban heat island (SUHI) studies have been conducted around the globe, however there is still a lack of information available regarding the intensity of SUHI (SUHII) in Bangladesh cities. This study focused on diurnal and seasonal SUHI variability, temporal trends and possible drivers in five major cities. Mean annual daytime SUHII ranged from 2.88 C for Dhaka to 0.84 C for Rajshahi, while nighttime intensity varied from 1.91 C (Chittagong) to 0.30 C (Sylhet). The pre-monsoon period exhibited the greatest magnitude and the seasonal amplitude during the winter season was positive for Dhaka and Khulna but negative for the other cities. Correlation analysis indicated that a dense city population, a high degree of imperviousness and the absence of greenery were likely to act singly, or in combination, to increase urban warming within these cities. An increasing warming trend during daytime was observed. The urban population of Bangladesh is projected to increase substantially in future (i.e., to 81.4 million by 2029), so the findings of this study provide valuable insights into this warming issue and will assist in the development of effective local-scale climate change adaptation plans.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2021EF002016", "year": 2021, "title": "Widespread Race and Class Disparities in Surface Urban Heat Extremes", "abstract": "Here we use remotely sensed land surface temperature measurements to explore the distribution of the United States' urban heating burden, both at high resolution (within cities or counties) and at scale (across the whole contiguous United States). While a rich literature has documented neighborhood-level disparities in urban heat exposures in individual cities, data constraints have precluded comparisons across locations. Here, drawing on urban temperature anomalies during extreme summer surface temperature events from all 1,056 US counties with more than 10 developed census tracts, we find that the poorest tracts (and those with lowest average education levels) within a county are significantly hotter than the richest (and more educated) neighborhoods for 76% of these counties (54% for education); we also find that neighborhoods with higher Black, Hispanic, and Asian population shares are hotter than the more White, non-Hispanic areas in each county. This holds in counties with both large and small spreads in these population shares, and for 71% of all counties the significant racial urban heat disparities persist even when adjusting for income. Although individual locations have different histories that have contributed to race- and class-based geographies, we find that the physical features of the urban environments driving these surface heat exposure gradients are fairly uniform across the country. Systematically, the disproportionate heat surface exposures faced by minority communities are due to more built-up neighborhoods, less vegetation, and\u2014to a lesser extent\u2014higher population density.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCS.2021.103146", "year": 2021, "title": "Context sensitivity of surface urban heat island at the local and regional scales", "abstract": "In this study we analysed the multi-annual (20022011) average summer surface urban heat island (SUHI) intensity of the 5000 largest urban clusters in Europe. We investigated its relationship with a proposed Gravitational Urban Morphology (GUM) index that can capture the local context sensitivity of SUHI. The GUM index was found to be an effective predictor of SUHI intensity. Together with other urban factors we built different multivariate linear regression models and a climate space based geographically weighted regression (GWR) model that can better predict SUHI intensity. As the GWR model captures the variation of influence from different urban factors on SUHI, it considerably outperformed linear models in predicting SUHI intensity in terms of R2 and other statistical criteria. By investigating the variation of GWR coefficients against background climate factors, we further built a nonlinear regression model that takes into account the sensitivity of SUHI to regional climate context. The nonlinear model showed comparable performance to that of the GWR model and it prevailed against all the linear models. Our work underlines the potential of SUHI reduction through optimising urban morphology, as well as the importance of integrating future urbanisation and climate change into the implementation of urban heat mitigation strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.UCLIM.2021.100846", "year": 2021, "title": "LCZ scheme for assessing Urban Heat Island intensity in a complex urban area (Beirut, Lebanon)", "abstract": "Thermal remote sensing has become widely used to monitor and study Urban Heat Island (UHI) by the use of satellite Land Surface Temperature (LST) data, and the Local Climate Zone (LCZ) scheme has established itself as the standard for assessing Urban Heat Island Intensity (UHII). A lot of research on LST-LCZ relationship has been done, but mainly in flat terrain. Some studies on UHI in mountainous areas have been conducted, but most of them considered the combined effect of land use/land cover and topography on temperature. To the best of our knowledge no study has been carried out on the LST-LCZ relationship in a complex topography area after removing the topography effect. This paper presents a methodology for assessing the impact of the urban structure on UHII in Beirut, a coastal city with heterogenous urban morphology and complex topography. It was concluded that the main urban variables which contribute to the spatial variability of topographically normalized LST are, in decreasing order of relative importance, the built-up ratio, the pervious surface ratio, the buildings' mean height and mean surface area. The difference in average temperatures between high-rise densely built LCZs and mostly pervious zones exceeded two degrees at nighttime.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.UCLIM.2022.101215", "year": 2022, "title": "A mechanistic assessment of urban heat island intensities and drivers across climates", "abstract": "The urban heat island effect (UHI) has been widely observed globally, causing climate, health, and energy impacts in cities. The UHI intensities have been found to largely depend on background climate and the properties of the urban fabric. Yet, a complete mechanistic understanding of how UHIs develop at a global scale is still missing. Using an urban ecohydrological and land-surface model (urban Tethys-Chloris) in combination with multi-source remote sensing data, we performed simulations for 49 large urban clusters across the Northern Hemisphere in 20092019 and analysed how surface and canopy air UHIs (SUHI and CUHI, respectively) develop during day and night. Biophysical drivers triggering the development of SUHIs and CUHIs have similar dependencies on background climate, but with different magnitudes. In humid regions daytime UHIs can be largely explained by the urban-rural difference in evapotranspiration, whereas heat convection and conduction are important in arid areas. Plant irrigation can largely promote daytime urban evapotranspiration only in arid and semi-arid climates. During night, heat conduction from the urban fabric to the environment creates large UHIs mostly in warm arid regions. Overall, this study presents a mechanistic quantification of how UHIs develop worldwide and proposes viable solutions for sustainable climate-sensitive mitigation strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2018EF001020", "year": 2019, "title": "Projections of Human Exposure to Dangerous Heat in African Cities Under Multiple Socioeconomic and Climate Scenarios", "abstract": "Human exposure to dangerous heat, driven by climatic and demographic changes, is increasing worldwide. Being located in hot regions and showing high rates of urban population growth, African cities appear particularly likely to face significantly increased exposure to dangerous heat in the coming decades. We combined projections of urban population under five socioeconomic scenarios\u2014shared socioeconomic pathways\u2014with projections of apparent temperature under three representative concentration pathways in order to explore future exposure to dangerous heat across 173 large African cities. Employing multiple shared socioeconomic pathway and representative concentration pathway combinations, we demonstrated that the aggregate exposure in African cities will increase by a multiple of 20-52, reaching 86-217 billion person-days per year by the 2090s, depending on the scenario. The most exposed cities are located in Western and Central Africa, although several Eastern African cities showed an increase of more than 2,000 times the current level by the 2090s, due to the emergence of dangerous heat conditions combined with steady urban population growth. In most cases, we found future exposure to be predominantly driven by changes in population alone or by concurrent changes in climate and population, with the influence of changes in climate alone being minimal. We also demonstrated that shifting from a high to a low urban population growth pathway leads to a slightly greater reduction in aggregate exposure than shifting from a high to a low emissions pathway (51% vs. 48%). This emphasizes the critical role that socioeconomic development plays in shaping heat-related health challenges in African cities.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2022GL100689", "year": 2022, "title": "UrbanRural Gradient in Urban Heat Island Variations Responsive to LargeScale Human Activity Changes During Chinese New Year Holiday", "abstract": "Large-scale human activity changes in megacities during Chinese New Year (CNY) are believed to significantly affect urban heat islands (UHIs). However, the urban-rural gradient in UHI variations responsive to human activity changes in cities remains largely unclear. Using in-situ surface air temperature obtained from a meteorological network that includes 3000-plus stations, we show that the mean UHI intensity (UHII) in 31 Chinese capitals is 0.52 \u00b1 0.23 K during the CNY holiday and 0.77 \u00b1 0.29 K in the reference period, indicating a UHII reduction of 0.25 \u00b1 0.20 K during the holiday. The reduced UHII decreased more from city core (0.54 K) to city periphery (0.071 K). We find that these UHII reductions were larger at night than during the day and were larger in northern subtropical and warm temperate climates than in other climates. These UHII reductions were mainly attributable to the decline in anthropogenic heat release.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2022GL099117", "year": 2022, "title": "An Approach to Characterizing the Spatial Pattern and Scale of Regional Heat Islands over Urban Agglomerations", "abstract": "Great difficulty in characterizing the spatial pattern and scale of regional surface urban heat islands (RSUHIs) over urban agglomerations is mainly attributed to the RSUHI extent exceeding urban boundaries and strong variations in the background climate state and land cover. A new method that successfully addresses these problems by applying the spatial similarity of the land surface temperature (LST) annual cycle in urban agglomerations is proposed to characterize the RSUHI spatial pattern and scale in the Yangtze River Delta of China. This method has good adaptability to complex terrain and climate variations and simultaneously identifies the RSUHI spatial pattern and scale. The RSUHI spatial extent averaged 3.7 \u00d7 104 km2 in 2003-2020, which is 1.5-2.0 times the urban extent, and had a fluctuating but increasing tendency. Rapid urbanization and the spatial pattern-shifting LST anomalies were mainly responsible for the fluctuating RSUHI extent during 2003-2020.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/IJERPH191912314", "year": 2022, "title": "Population-Based Disparities in U.S. Urban Heat Exposure from 2003 to 2018", "abstract": "Previous studies have shown, in the United States (U.S.), that communities of color are exposed to significantly higher temperatures in urban environments than complementary White populations. Studies highlighting this disparity have generally been cross-sectional and are therefore snapshots in time. Using surface urban heat island (SUHI) intensity data, U.S. Census 2020 population counts, and a measure of residential segregation, this study performs a comparative analysis between census tracts identified as prevalent for White, Black, Hispanic and Asian populations and their thermal exposure from 2003 to 2018. The analysis concentrates on the top 200 most populous U.S. cities. SUHI intensity is shown to be increasing on average through time for the examined tracts. However, based on raw observations the increase is only statistically significant for White and Black prevalent census tracts. There is a 1.25 K to ~2.00 K higher degree of thermal exposure on average for communities of color relative to White prevalent areas. When examined on an inter-city basis, White and Black prevalent tracts had the largest disparity, as measured by SUHI intensity, in New Orleans, LA, by <6.00 K. Hispanic (>7.00 K) and Asian (<6.75 K) prevalent tracts were greatest in intensity in San Jose, CA. To further explore temporal patterns, two models were developed using a Bayesian hierarchical spatial temporal framework. One models the effect of varying the percentages of each population group relative to SUHI intensity within all examined tracts. Increases in percentages of Black, Hispanic, and Asian populations contributed to statistically significant increases in SUHI intensity. White increases in population percentage witnessed a lowering of SUHI intensity. Throughout all modeled tracts, there is a statistically significant 0.01 K per year average increase in SUHI intensity. A second model tests the effect of residential segregation on thermal inequity across all examined cities. Residential segregation, indeed, has a statistically significant positive association with SUHI intensity based on this portion of the analysis. Similarly, there is a statistically significant 0.01 K increase in average SUHI intensity per year for all cities. Results from this study can be used to guide and prioritize intervention strategies and further urgency related to social, climatic, and environmental justice concerns.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCS.2019.101518", "year": 2019, "title": "Spatial patterns and driving factors of surface urban heat island intensity: A comparative study for two agriculture-dominated regions in China and the USA", "abstract": "Urban heat island (UHI) effect causes tremendous ecological and environmental consequences. A better understanding of its spatial pattern and driving factors is highly required for designing effective mitigation strategies and adaptation measures. This study compared spatial patterns of surface UHI intensity (SUHII) and their driving factors between two agriculture-dominated regions (i.e., BeijingTianjinHebei (BTH), China and IllinoisIndianaOhio (IIO), the USA) based on the MODIS land surface temperature dataset. The results showed that: (1) IIO had significantly stronger daytime SUHII than BTH, while the nighttime SUHII showed an opposite phenomenon. (2) SUHIIs of different time were positively correlated in IIO, but the winter daytime SUHII was negatively correlated with the nighttime SUHII in BTH. (3) Spatial variations of summer SUHII were better predicted in IIO than that in BTH, but the opposite result was found for winter SUHII. (4) Some regression coefficients of the multiple linear regression models when modeling winter daytime SUHII were opposite between IIO and BTH. Findings of this study indicated different dominant surface energy processes in controlling the spatial pattern of SUHII in these two regions of different countries and recommended varied adaptation measures and mitigation strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.157662", "year": 2022, "title": "Exploring surface urban heat island (SUHI) intensity and its implications based on urban 3D neighborhood metrics: An investigation of 57 Chinese cities", "abstract": "Excessive urban temperature exerts a substantially negative impact on urban sustainability. Three-dimensional (3D) landscapes have a great impact on urban thermal environments, while their heat conditions and driving factors still remain unclear. This study mapped urban 3D neighborhoods and their associated SUHI (surface urban heat island) intensities in summer daytime across 57 Chinese cities, and then explored their relationships, driving factors as well as implications. Nine categories of urban 3D neighborhoods existed in Chinese cities and the 3D neighborhood of High Density & Medium Rise (HDMR) contributed the largest share of urban areas. The distribution of 3D neighborhoods varied among cities due to their distinct natural and economic traits. The average SUHI intensity can amount to 4.27 C across all Chinese 3D neighborhoods. High Density & Low Rise (HDLR) and HDMR presented higher SUHI intensities than other 3D neighborhoods in China. Urban green space (UGI) and building height (BH) had great influences on SUHI intensities. The relative contribution of UGI decreased with the increase of building density and building height, but BH presented the opposite trend. The interaction of urban 3D landscapes and function zones led to highly complicated urban thermal environments, with higher SUHI intensities in industrial zones. Besides, the SUHI intensities of 3D neighborhoods presented great diurnal and seasonal variations, with higher SUHI intensities in HDHR and HDMR at nighttime in winter and summer. What's more, urban residents may suffer unequal heat risk inside cities due to the deviations of SUHI intensities among different 3D neighborhoods. It could be a highly effective way to mitigate SUHI effects in cities by increasing urban greening and improving urban ventilation.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1038/S41612-018-0055-3", "year": 2018, "title": "Downwind footprint of an urban heat island on air and lake temperatures", "abstract": "The urban heat island (UHI) effect was first documented ~200 years ago, making it the longest recognized anthropogenic effect on climate. Although anomalous heating in cities has been meticulously characterized, less is known about how the UHI affects surrounding regions. It is hypothesized that downwind of cities a heat plume forms due to the advection of urban heat. This heat transport may have impacts beyond heating of the surface, such as disrupting atmospheric convection and influencing boundary layer structure, which influences weather, air quality, and human health. Here, a lagrangian atmospheric transport model, forced with archived data from a numerical weather model, is used to generate a three-dimensional map of an urban heat plume for a major city, Chicago. We document significant heating 100200 m above the surface and 70 km downwind of the city. Over Lake Michigan, the scale of the plume is truncated nearly in half (~40 km), suggesting the lake is acting as a sink for the exported urban heat. Using satellite lake surface temperatures, we observed a disruption of the diurnal pattern of lake temperature beneath the plume, which supports a possible role of the lake in absorbing the heat plume. The results provide unique quasi-observational evidence for a significant footprint of cities on regional atmospheric structure and potentially on adjacent aquatic bodies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/SU12114415", "year": 2020, "title": "Study on the Spatial Pattern of an Extreme Heat Event by Remote Sensing:", "abstract": "The intensity and frequency of extreme heat events are increasing globally, which has a great impact on resident health, social life, and ecosystems. Detailed knowledge of the spatial heat pattern during extreme heat events is important for coping with heat disasters. This study aimed to monitor the characteristics of the spatial pattern during the 2013 heat wave in the Yangtze River Delta (YRD), China, based on the remote sensing estimated gridded air temperature (Ta). Based on the land surface temperature (Ts), normalized difference vegetation index (NDVI), built-up area, and elevation derived from multi-source satellite data, the daily maximum air temperature (Ta_max) during the heat wave was mapped by the random forest (RF) algorithm. Based on the remotely sensed Ta, heat intensity index (HII) was calculated to measure the spatial pattern of heat during this heat wave. Results indicated that most areas in the YRD suffered from extreme heat, and the heat pattern also exhibited obvious spatial heterogeneity. Cities located in the Taihu Plain and the Hangjiahu Plain generally had high HII values. The northern plain in the YRD showed relatively lower HII values, and mountains in the southern YRD showed the lowest HII values. Heat proportion index (HPI) was calculated to qualify the overall heat intensity of each city in the YRD. Wuxi, Changzhou, and Shanghai showed the highest HPI values, indicating that the overall heat intensities in these cities were higher than others. Yancheng, Zhoushan, and Anqing ranked last. This study provides a good reference for understanding the pattern of heat during heat waves in the YRD, which is valuable for heat wave disaster prevention.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1038/S41586-019-1512-9", "year": 2019, "title": "Magnitude of urban heat islands largely explained by climate and population", "abstract": "Urban heat islands (UHIs) exacerbate the risk of heat-related mortality associated with global climate change. The intensity of UHIs varies with population size and mean annual precipitation, but a unifying explanation for this variation is lacking, and there are no geographically targeted guidelines for heat mitigation. Here we analyse summertime differences between urban and rural surface temperatures (Ts) worldwide and find a nonlinear increase in Ts with precipitation that is controlled by water or energy limitations on evapotranspiration and that modulates the scaling of Ts with city size. We introduce a coarse-grained model that links population, background climate, and UHI intensity, and show that urbanrural differences in evapotranspiration and convection efficiency are the main determinants of warming. The direct implication of these nonlinearities is that mitigation strategies aimed at increasing green cover and albedo are more efficient in dry regions, whereas the challenge of cooling tropical cities will require innovative solutions.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.149553", "year": 2021, "title": "Quantifying the response of surface urban heat island to urban greening in global north megacities", "abstract": "Urban heat island, a phenomenon that urban temperature is higher than the rural area nearby, affects directly citizens' human health and well-being. However, the cooling effect from urban green space (UGS) and the attribution of the different land processes to surface urban heat island intensity (SUHI) under different background climates remains unclear. The coarse-grained model was used to estimate summer SUHI in three different background climatic zones and for seven agglomerations (BTH, JP, LD, NAAC, NAGL, YZ, UQ). Results indicate that (1) the temperate zone had the highest daytime SUHI (010 C), while the arid zone has the lowest daytime SUHI (12 C). In both temperate and cold zone, the daytime SUHI was higher than the nighttime SUHI. The SUHI in downtown was higher (more than 2 C) than in the suburbs. (2) The increasing precipitation can enhance daytime SUHI while can weaken nighttime SUHI in all three climatic zones. The increasing temperature tends to enhance SUHI in both daytime and nighttime (exclude UQ). (3) The cooling effects of UGS in daytime SUHI were highly dependent on the background climate (cold > temperate > arid). (4) The nighttime SUHI could be effectively offset when UGSFs were greater than 0.48, 0.82, 0.97, 0.95 in NAAC, NAGL, YZ, and UQ. This article highlights the different feedback of urban green space to UHII and supports green infrastructure intervention as an effective means of reducing urban heat stress at urban agglomeration scales.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.JAG.2020.102131", "year": 2020, "title": "Spatially non-stationary effect of underlying driving factors on surface urban heat islands in global major cities", "abstract": "Urban heat island (UHI) effect is among the most typical characteristics of urban climate. The analysis of surface UHI (SUHI) mechanisms has received the most extensive attention in the world. Here, we quantify the diurnal and seasonal SUHI intensity (SUHII) in global 419 major cities during the period 2003-2013. A geographically weighted regression (GWR) was established to assess the relationships between SUHII and several driving factors, and it further was compared to the ordinary least square (OLS) and stepwise multiple linear regression (SMLR) models. We show that GWR model has higher determination coefficient (R2) than OLS and SMLR models (Time: summer daytime, summer night, winter daytime and winter nighttime; GWR: 0.805, 0.458, 0.699 and 0.582; OLS: 0.732, 0.347, 0.473 and 0.320; SMLR: 0.732, 0.341, 0.468 and 0.316), indicating the spatially non-stationarity in the relationships. During the day, both vegetation activity and tree cover fraction have stronger cooling effect on SUHI in the summer of Asia. At night, there are stronger albedo effects on SUHI in the summer of Eastern Asia and Western North America and in the winter of Eastern Asia. Furthermore, temperature has stronger effect on daytime SUHI in Africa, Europe and South America in summer, and precipitation has stronger effect on nighttime SUHI in Africa and Europe in summer. Our results emphasize the spatial variation of the relationships between SUHII and relevant driving factors across global major cities, further indicating that the spatially non-stationary effect of driving factors on SUHII need to be considered in the future.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1088/1748-9326/AC36F8", "year": 2021, "title": "Enhanced surface urban heat islands due to divergent urban-rural greening trends", "abstract": "Abstract\r\n \r\n Satellite observations show that the surface urban heat island intensity (SUHII) has been increasing over the last two decades. This is often accompanied by an increased urban-rural contrast of vegetation greenness. However, the contribution of uneven vegetation trends in urban and rural areas to the trend of SUHII is unclear, due to the confounding effects of climate change and changes in man-made infrastructures and anthropogenic heat sources. Here we use a data-model fusion approach to quantify such contributions during the peak growing season. We show that the LAI\r\n dif\r\n (the urban-rural difference of leaf area index) is increasing (\r\n P\r\n < 0.05) in 189 of the selected 228 global megacities. The increasing trend of LAI\r\n dif\r\n from 2000 to 2019 accounts for about one quarter of the trend in satellite-derived SUHII, and the impact is particularly evident in places with rapid urbanization and rural cropland intensification. The marginal sensitivity of SUHII to LAI\r\n dif\r\n is the strongest in hot-humid megacities surrounded by croplands and in hot-dry megacities surrounded by mixed woody and herbaceous vegetation. Our study highlights the role of long-term vegetation trends in modulating the trends of urban-rural temperature differences.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S00704-021-03872-X", "year": 2022, "title": "Changes in urbanization and urban heat island effect in Dhaka city", "abstract": "The study aimed to assess the changes in urban areas and UHI effects in Dhaka city, Bangladesh, from 2001 to 2017, using Moderate Resolution Imaging Spectroradiometer (MODIS) daily day- and nighttime land surface temperature (LST) data from 2001 to 2017. The expansion of the city was calculated using the city clustering algorithm (CCA). The temperature of the identified urbanized area was analyzed and compared with the adjacent regions. The changes in urban temperature were estimated using non-parametric statistical methods. The results showed that Dhaka city's land surface area has grown by 25.33% and its inhabitants by 76.65% during 2001-2017. Urban expansion and dense settlements caused an increase in average temperature in some areas of Dhaka city nearly 3 \u00b0C compared to that at its boundary. The day and night temperature differences at Dhaka city's warmest location and the coolest point outside the city were nearly 7 \u00b0C and 5 \u00b0C, respectively. The city's annual average day- and nighttime temperatures was increasing at a rate of 0.03 \u00b0C and 0.023 \u00b0C/year over the period of the last 17 years. The rising temperature would increase the UHI effect in the future, which, combined with high humidity, may cause a significant increase in public health risk in the city if mitigation practices are not followed.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.JCLEPRO.2021.125806", "year": 2021, "title": "Environmental impacts of shifts in energy, emissions, and urban heat island during the COVID-19 lockdown across Pakistan", "abstract": "Restrictions on human and industrial activities due to the coronavirus (COVID-19) pandemic have resulted in an unprecedented reduction in energy consumption and air pollution around the world. Quantifying these changes in environmental conditions due to government-enforced containment measures provides a unique opportunity to understand the patterns, origins and impacts of air pollutants. During the lockdown in Pakistan, a significant reduction in energy demands and a decline of 1786 GWh (gigawatt hours) in electricity generation is reported. We used satellite observational data for nitrogen dioxide (NO2), carbon monoxide (CO), sulphur dioxide (SO2), aerosol optical depth (AOD) and land surface temperature (LST) to explore the associated environmental impacts of shifts in energy demands and emissions across Pakistan. During the strict lockdown period (March 23 to April 15, 2020), we observed a reduction in NO2 emissions by 40% from coal-based power plants followed by 30% in major urban areas compared to the same period in 2019. Also, around 25% decrease in AOD (at 550 nm) thickness in industrial and energy sectors was observed although no major decrease was evident in urban areas. Most of the industrial regions resumed emissions during the 3rd quarter of April 2020 while the urban regions maintained reduced emissions for a longer period. Nonetheless, a gradual increase has been observed since April 16 due to relaxations in lockdown implementations. Restrictions on transportation in the cities resulted in an evident drop in the surface urban heat island (SUHI) effect, particularly in megacities. The changes reported as well as the analytical framework provides a baseline benchmark to assess the sectoral pollution contributions to air quality, especially in the scarcity of ground-based monitoring systems across the country.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1117/12.2501937", "year": 2018, "title": "Relationship between urban heat island and green infrastructure fraction in Harbin", "abstract": "Urbanisation contributed to the presence of urban heat island phenomenon, and aggravated urban heat island effect intensity with the improvement of urbanisation level. Overheat weather condition caused severe threat to human life and health, while green infrastructure including water bodies has been validated to be able to reduce urban land surface temperature in different extent. To examine the impact of green infrastructure on urban heat island effect in Harbin, with the aid of ENVI and geographic information system software, this paper retrieved seasonal Harbin land surface temperature from 2000 to 2015 using Landsat series and MODIS 8-day remote sensing data, and further computed surface urban heat island intensity(SUHII). Then, to build the quantitative relationship between green infrastructure fraction and urban heat island intensity applying regression analysis method. Finally, by means of ENVI-MET software, this article simulated urban heat island intensity change based on different green infrastructure scenarios. The results showed that, as far as administrative region of Harbin scale, surface urban heat island intensity both in summer and in winter reduced from 2000(6.55C in summer, 4.15C in winter) to 2015(2.6C in summer, 0.47C in winter), and SUHII in summer is higher than it in winter except 2005; Green infrastructure fraction is negative correlated with SUHII; Simulation result indicated that increase on green infrastructure would facilitate to mitigation of urban heat island effect. The result of this study would provide some help and advice for land use planning decision and urban construction in the future of Harbin.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCS.2020.102060", "year": 2020, "title": "Evaluation of urban heat islands using local climate zones and the influence of sea-land breeze", "abstract": "The Local Climate Zone (LCZ) scheme is an urban form and land cover/land use classification system used to study urban heat islands (UHIs). Many studies have evaluated the relationship between LCZs and air temperature. While the intensity and spatial pattern of an UHI can be influenced by the land-sea breeze, especially in coastal cities, few studies have been done to examine this using the LCZ scheme. In this study, Sendai, Japan, has been selected as a case study to evaluate whether the LCZ scheme can be used to study UHIs that are exposed to sea-land breeze since it has two urban-rural areas: mountain side and coastal side. UHI analysis was based on LCZ classes with GIS-derived geometric and land cover properties. By dividing Sendai into two regions along its urban center, the mitigating effects of sea-land breeze on the magnitudes of UHIs in each urban-rural area were demonstrated. Based on the results of this study, two specific UHI mitigation strategies were proposed for Sendai. This study confirmed that the LCZ scheme can be used by urban planners to assess both surface UHI (SUHI) and UHI effects, and proposed a feasible process for developing targeted UHI mitigation strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/RS11182136", "year": 2019, "title": "New ECOSTRESS and MODIS land surface temperature data reveal fine-scale heat vulnerability in cities: A case study for Los Angeles County, California", "abstract": "Rapid 21st century urbanization combined with anthropogenic climate warming are significantly increasing heat-related health threats in cities worldwide. In Los Angeles (LA), increasing trends in extreme heat are expected to intensify and exacerbate the urban heat island effect, leading to greater health risks for vulnerable populations. Partnerships between city policymakers and scientists are becoming more important as the need to provide data-driven recommendations for sustainability and mitigation efforts becomes critical. Here we present a model to produce heat vulnerability index (HVI) maps driven by surface temperature data from National Aeronautics and Space Administrations (NASA) new Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) thermal infrared sensor. ECOSTRESS was launched in June 2018 with the capability to image fine-scale urban temperatures at a 70 m resolution throughout different times of the day and night. The HVI model further includes information on socio-demographic data, green vegetation abundance, and historical heatwave temperatures from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor onboard the Aqua spacecraft since 2002. During a period of high heat in July 2018, we identified the five most vulnerable communities at a sub-city block scale in the LA region. The persistence of high HVI throughout the day and night in these areas indicates a clear and urgent need for implementing cooling technologies and green infrastructure to curb future warming.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2022AV000729", "year": 2022, "title": "Lower Urban Humidity Moderates Outdoor Heat Stress", "abstract": "Surface temperature is often used to examine heat exposure in multi-city studies and for informing urban heat mitigation efforts due to scarcity of urban air temperature measurements. Cities also have lower relative humidity, traditionally not accounted for in large-scale observational urban heat risk assessments. Here, using crowdsourced measurements from over 40,000 weather stations in \u2248600 urban clusters in Europe, we show the moderating effect of this urbanization-induced humidity reduction on outdoor heat stress during the 2019 heatwave. We demonstrate that daytime differences in heat index between urban clusters and their surroundings are weak, and associations of this urban-rural difference with background climate, generally examined from the surface temperature perspective, are diminished due to moisture feedbacks. We also examine the spatial variability of surface temperature, air temperature, and heat index within these clusters\u2014relevant for detecting hotspots and potential disparities in heat exposure\u2014and find that surface temperature is a poor proxy for the intra-urban distribution of heat index during daytime. Finally, urban vegetation shows much weaker (\u223c1/6th as strong) associations with heat index than with surface temperature, which has broad implications for optimizing urban heat stress mitigation strategies. These findings are valid for operational metrics of heat stress for shaded conditions (apparent temperature and humidex), thermodynamic proxies (wet-bulb temperature), and empirical heat indices. Based on this large-scale empirical evidence, surface temperature, used due to the lack of better alternatives, may not be suitable for accurately informing heat mitigation strategies within and across cities, necessitating more urban-scale observations and better urban-resolving models.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/B978-0-323-85527-3.00022-4", "year": 2022, "title": "Complementarity of renewable energy sources in the context of the heating sector", "abstract": "This chapter presents an analysis of solar and/or wind-powered air-source heat pumps supplying domestic space and hot water demand in Poland. The analysis has been performed from the perspective of long-term heat demand, coefficient of performance, and renewables variability spanning across the years 19802019 with an hourly resolution. The objective of the analysis was to investigate the potential mismatch between supply and demand for three electricity supply options: only solar, only wind, and the hybrid system in a 40-years climate change approach. In the hybrid configuration, the capacities of solar and wind generators have been adjusted in such a way that electricity from PV and later wind generator used by heat pump provides exactly 50% of the annual heat demand. The results revealed a better match of wind energy when it comes to supplying heating loads in Poland. Nevertheless, a significant temporal mismatch between demand and supply calls for long-term, seasonal storage solutions.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/RS15133385", "year": 2023, "title": "Spatiotemporal Features of the Surface Urban Heat Island of Bacau City", "abstract": "Using MODIS and Landsat LST images, the present paper advances a series of results on the characteristics of the surface heat island (SUHI) of Bac\u0103u City (Romania) during the warm season (April to September) for a period of 20 years (2001\u20132020). At the same time, given their higher temporal resolution and their availability for both day and night, MODIS LST was used to understand the spatial features of the SUHI in relation to land use. In this way, a total of 946 MODIS Terra and 483 Landsat satellite images were used to outline the main LST characteristics of the days with clear sky in this middle-sized city in northeast Romania. In order to analyze MODIS LST changes in relation to land use changes in the period 2001\u20132018, we used the standardized CORINE Land Cover datasets. With the help of the Rodionov test, we were able to determine the geometry and intensity of the SUHI. During the day, the spatial extension of the SUHI reaches its maximum level and is delimited by the isotherm of 31.0 \u00b0C, which is 1.5\u20132.0 \u00b0C warmer than the neighboring non-urban areas. During the night, the SUHI has a more regulated spatial extension around the central area of the city, delimited by the 15.5 \u00b0C isotherm with LST values that are 1.0\u20131.5 \u00b0C warmer than the surrounding non-urban areas. Additionally, from a methodological point of view, we highlight that resampled MODIS and Landsat images at a spatial resolution of 500 m can be used with confidence to understand the detailed spatial features of the SUHI. The results of this study could help the elaboration of future policies meant to mitigate the effects of urbanization on the SUHI in an era of increasing air temperatures during summer.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.5194/NHESS-23-1313-2023", "year": 2023, "title": "Heat wave monitoring over West African cities: uncertainties", "abstract": "Heat waves can be one of the most dangerous climatic hazards affecting the planet, having dramatic impacts on the health of humans and natural ecosystems as well as on anthropogenic activities, infrastructures and economy. Based on climatic conditions in West Africa, the urban centres of the region appear to be vulnerable to heat waves. The goals of this work are firstly to assess the potential uncertainties encountered in heat wave detection and secondly to analyse their recent trend in West Africa cities during the period 1993-2020. This is done using two state-of-the-art reanalysis products, namely the fifth-generation European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis (ERA5) and Modern-Era Retrospective analysis for Research and Applications (MERRA), as well as two local station datasets, namely Dakar-Yoff in Senegal and A\u00e9roport F\u00e9lix Houphou\u00ebt-Boigny, Abidjan, in C\u00f4te d'Ivoire. An estimate of station data from reanalyses is processed using an interpolation technique: the nearest neighbour to the station with a land sea mask \u22650.5. The interpolated temperatures from local stations in Dakar and Abidjan show slightly better correlation with ERA5 than with MERRA. Three types of uncertainty are discussed: the first type of uncertainty is related to the reanalyses themselves, the second is related to the sensitivity of heat wave frequency and duration to the threshold values used to monitor them, and the last one is linked to the choice of indicators and the methodology used to define heat waves. Three sorts of heat wave have been analysed, namely those occurring during daytime, nighttime, and both daytime and nighttime concomitantly. Four indicators have been used to analyse heat waves based on 2 m temperature, humidity, 10 m wind or a combination of these. We found that humidity plays an important role in nighttime events; concomitant events detected with wet-bulb temperature are more frequent and located over the northern Sahel. Strong and more persistent heat waves are found in the continental (CONT) region. For all indicators, we identified 6 years with a significantly higher frequency of events (1998, 2005, 2010, 2016, 2019 and 2020), possibly due to higher sea surface temperatures in the equatorial Atlantic Ocean corresponding to El Ni\u00f1o events for some years. A significant increase in the frequency, duration and intensity of heat waves in the cities has been observed during the last decade (2012-2020); this is thought to be a consequence of climate change acting on extreme events.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.UCLIM.2023.101455", "year": 2023, "title": "Exploring the seasonality of surface urban heat islands using enhanced", "abstract": "Understanding the seasonal variations in surface urban heat island (SUHI) in different local climate zones (LCZs) is crucial to efforts to reduce the impacts of urban warming on local residents. However, such an understanding is constrained by the lack of land surface temperatures (LSTs) at both high spatial and temporal resolutions. This study created time series LSTs by fusing Landsat 8 satellite data and gap-filled MODIS products to further analyses of the SUHI seasonality in a semi-arid city, Xi'an, China. The results showed that LSTs of the open building types were generally lower than those of the compact building types. The highest SUHI intensity (7.17 C) was found in compact mid-rise buildings (LCZ2), whereas lowest (3.62 C) was found in open high-rise buildings (LCZ4) in July. The SUHI intensity peaked about 1723 days later than the background LST. The annual SUHI hysteresis cycles exhibited an anti-clockwise concave-up pattern in the monsoon-influenced hot-summer humid continental climate (Dwa per Koppen-Geiger climate scheme). The SUHI intensity in autumn was higher than in spring under the same background LST. These results provide valuable information for developing heat mitigation strategies in different seasons.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/RS15112750", "year": 2023, "title": "Comparisons of the Urbanization Effect on Heat Stress Changes in", "abstract": "While rapid urbanization promotes social and economic development, it exacerbates human outdoor thermal comfort, which increases the risks to human health. This paper uses four thermal comfort indices and multiple satellite observations to explore the urbanization effect on summer heat stress in Guangdong from 1979\u20132018, a coastal province of China. Two types of thermal comfort index are used here, namely the direct thermal comfort index (Heat Index, HI; Temperature\u2013Humidity Index, THI; Discomfort Index, DI) and the physiological thermal comfort index (Universal Thermal Climate Index, UTCI). We compare the differences in the urbanization effects on the changes in the three direct thermal comfort indices (HI, THI, and DI) and a physiological thermal comfort index (UTCI). The results show that all four thermal comfort indices indicate an overall warming trend. Of them, urban sites show a higher warming trend than rural sites, indicating that heat stress changes are significantly influenced by urbanization from 1979\u20132018, which is consistent with the effect of urbanization on surface air temperature. However, except for the UTCI, this warming of direct thermal comfort indices affected by urbanization has become insignificant under the regional vegetation greening from 2004\u20132018 (also consistent with surface air temperature). This is primarily attributed to the different effects of wind speed on the physiological thermal comfort index in urban and rural areas: Decreasing wind speeds in urban areas lead to an increase in UTCI, while wind speeds in rural areas increase instead and decrease UTCI, thus widening the UTCI differences between urban and rural areas. Our results indicate that urbanization has a different effect on thermal comfort indices. When using the thermal comfort index, it is necessary to consider that different thermal comfort indices may bring different results. UTCI considers more factors that affect human heat perception, so it can better describe human outdoor thermal comfort. It also highlights the importance of urban ventilation and urban greenness in mitigating urban outdoor thermal comfort in the sustainable construction of future urbanization in coastal cities.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCITOTENV.2023.164496", "year": 2023, "title": "Changes in air pollution, land surface temperature, and urban heat", "abstract": "COVID-19 has notably impacted the world economy and human activities. However, the strict urban lockdown policies implemented in various countries appear to have positively affected pollution and the thermal environment. In this study, Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) and aerosol optical depth (AOD) data were selected, combined with Sentinel-5P images and meteorological elements, to analyze the changes and associations among air pollution, LST, and urban heat islands (UHIs) in three urban agglomerations in mainland China during the COVID-19 lockdown. The results showed that during the COVID-19 lockdown period (February 2020), the levels of the AOD and atmospheric pollutants (fine particles (PM2.5), NO2, and CO) significantly decreased. Among them, PM2.5 and NO2 decreased the most in all urban agglomerations, by >14 %. Notably, the continued improvement in air pollution attributed to China's strict control policies could lead to overestimation of the enhanced air quality during the lockdown. The surface temperature in all three urban agglomerations increased by >1 C during the lockdown, which was mainly due to climate factors, but we also showed that the lockdown constrained positive LST anomalies. The decrease in the nighttime urban heat island intensity (UHIInight) in the three urban agglomerations was greater than that in the daytime quantity by >25 %. The reduction in surface UHIs at night was mainly due to the reduced human activities and air pollutant emissions. Although strict restrictions on human activities positively affected air pollution and UHIs, these changes were quickly reverted when lockdown policies were relaxed. Moreover, small-scale lockdowns contributed little to environmental improvement. Our results have implications for assessing the environmental benefits of city-scale lockdowns.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3389/FRSC.2023.1084573", "year": 2023, "title": "Two decades of nighttime surface urban heat island intensity analysis over nine major populated cities of India and implications for heat stress", "abstract": "Warmer global climate and urban heat islands (UHIs) interact, by exacerbating heatwaves and increasing the extreme heat days in cities. The implications of added heat stress in urban environments due to intensifying surface UHIs (SUHIs) is of utmost concern. Seasonal, annual and decadal nighttime SUHI intensities (SUHIIs), from 2001 to 2020, for nine major populated cities of India are analyzed. This includes five megacities- Delhi, Mumbai, Kolkata, Bangalore, and Chennai, and four incipient megacities- Hyderabad, Ahmedabad, Surat, and Pune. The key role of increasing urbanization (pre- and post-2010) in expansion and intensification of nighttime SUHIs in India is highlighted. For all cities either pre-monsoon (MAM) or winter (December-February; DJF) seasons show the strongest SUHII development. During the 20012010, and the 20112020 decade, a nighttime SUHII maxima of respectively (i) 2.1C and 2.5C for Delhi, (ii) 1.3C and 1.5C for Mumbai, (iii) 1.3C and 1.5C for Kolkata, (iv) 0.6C and 1.0C Bangalore, (v) 1.7C and 1.9C for Chennai, (vi) 1.8C and 2.3C for Hyderabad, (vii) 2.8C and 3.1C for Ahmedabad, (viii) 1.9C and 2.4C for Surat, and (ix) 0.8C and 1.3C for Pune is noted. Further, all incipient megacities showed a mean annual growth rate of nighttime SUHII of over 0.007C/year, substantially greater than in the megacities. High SUHII magnitudes, greater growth rates of SUHII, and huge populations, severely compounds the vulnerability of Indian cities to excessive heat exposure risk, especially during MAM heatwaves. Lastly, the implications of nighttime SUHII findings from the present study, on the increase in heat stress, the loss of labor productivity and the rise in heat-related mortality rate is emphasized. The study recommends implementation of city-specific action plans to mitigate the heat stressed urban environment. Targeted use of cooling strategies in localized hotspots within the urban areas where high intensity SUHIs are likely to form is also suggested.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S10668-023-03254-5", "year": 2023, "title": "Spatio-temporal evolution of surface urban heat island over", "abstract": "India is one of the rapidly urbanizing major economies in the developing world. As it embarks on its urban transition, many small tier-2 cities are already experiencing a large-scale transformation. This study examines the effects of surface urban heat island intensity (SUHI) effect from 2001 to 2020 on a tropical coastal urban complex, Bhubaneswar and Cuttack, a rapidly expanding tier-2 twin city in the Eastern Indian region. Our study reveals a clear discernible annual nighttime SUHI for both Bhubaneswar and Cuttack (0.75 0.08 and 1.22 0.07 C) with a growth rate of 0.18 0.07 and 0.13 0.07 C/decade, respectively. Surprisingly, the annual daytime SUHI is weakening for Bhubaneswar. Both night and daytime SUHI showed substantial seasonality with a clear asymmetry during the day and night. Daytime urban cool island effect was observed for Cuttack with Bhubaneswar reporting weak SUHI for daytime during dry seasons. Around the periphery of the cities, the diurnal temperature range (DTR) was found to be the highest. Furthermore, A decrease of 2 C in the DTR has been reported over the past two decades. The urbanization effect on the local thermal climate of both cities is seen beyond the physical urban limits. Such changes, even in tier-2 cities, have significant potential to modulate local climate and underscore the need for detailed studies in the rapidly urbanizing cities of India and the world to enable disaster resilience, climate-proofing, and sustainability.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.UCLIM.2023.101529", "year": 2023, "title": "Modeling the intensity of surface urban heat island based on the", "abstract": "The urban heat island (UHI) effect is anticipated to be intensified and cause severe damage to human society under future urbanization and climate change. Due to the complicated human-nature interactions in the urban domain, it is challenging to characterize the intensity of UHI quantitatively, especially at the global scale. Here, we proposed a framework to estimate the surface urban heat island intensity (SUHII) based on satellite-derived land surface temperature (LST) and the derived impervious surface area (ISA) data across 355 cities worldwide from 2003 to 2018. First, we employed linear regression models to estimate LST using ISA as the explanatory variable, given that the LST generally elevated with increasing urban intensity along the urban-rural gradient. Then, using the modeled LST, we estimated the spatiotemporal patterns of SUHII worldwide. The established linear regression models with ISA as the explanatory variable perform reasonably well in estimating LST for both daytime and nighttime, with average RMSEs of 1.40 and 0.80 C, respectively. The resulting SUHII reasonably captures the spatial heterogeneity across cities in the world, with the highest value in the tropical region at daytime and in the arid region at nighttime. The estimated and observed SUHII show good agreement with average R2 values of 0.81 and 0.72 for daytime and nighttime, respectively. Using ISA as an indicator for LST estimation, this study first implemented a comprehensive estimation of SUHII at the global scale. The proposed methodology is of great potential to project future SUHII by expanding urban impervious surfaces under diverse scenarios jointly determined by shared socioeconomic pathways and climate change scenarios.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S11356-023-26673-3", "year": 2023, "title": "Differences in urban heat island and its driving factors between central", "abstract": "Urban heat island (UHI) is one of the important effects of urbanization on built environment. Land surface temperature data was taken from moderate-resolution imaging spectroradiometer (MODIS) to investigate the long-term spatiotemporal patterns of UHI in Wuhan during 2001~2018 and, the UHI intensity changes of built-up land in 13 administrative regions in Wuhan were analyzed. Furthermore, 34 spatial error models and 34 ordinary least squares models were established and compared. Spatial error models showed good fitting effect, which were used to determine the influence of normalized difference vegetation index (NDVI), normalized difference building index (NDBI), and socialeconomic factors (population and nighttime light) on UHI intensity in central urban area and new urban area. The explanatory power changes of these four indicators during 2001~2018 were explored as well. The average UHI intensity in 2014~2018 has increased by about 0.45 C compared to that in 2001~2005. NDBI is the most dominant factor contributing to the increase in temperature. The impact of NDVI on UHI intensity changes from negative to positive, and the impact of NDBI on UHI intensity in central urban area is weakened during 20012018. Socialeconomic factors have a greater impact on new urban area than on central urban area. These findings show the effects and the explanatory power changes of driving factors during 18 years, which can provide a better understanding of the formation and development of UHI and support for the future urban planning of Wuhan.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.RSE.2023.113602", "year": 2023, "title": "Anthropogenic heat variation during the COVID-19 pandemic control", "abstract": "Anthropogenic heat (AH) is an important input for the urban thermal environment. While reduction in AH during the Coronavirus disease 2019 (COVID-19) pandemic may have weakened urban heat islands (UHI), quantitative assessments on this are lacking. Here, a new AH estimation method based on a remote sensing surface energy balance (RS-SEB) without hysteresis from heat storage was proposed to clarify the effects of COVID-19 control measures on AH. To weaken the impact of shadows, a simple and novel calibration method was developed to estimate the SEB in multiple regions and periods. To overcome the hysteresis of AH caused by heat storage, RS-SEB was combined with an inventory-based model and thermal stability analysis framework. The resulting AH was consistent with the latest global AH dataset and had a much higher spatial resolution, providing objective and refined features of human activities during the pandemic. Our study of four Chinese megacities (Wuhan, Shanghai, Beijing, and Guangzhou) indicated that COVID-19 control measures severely restricted human activities and notably reduced AH. The reduction was up to 50% in Wuhan during the lockdown in February 2020 and gradually decreased after the lockdown was eased in April 2020, similar to that in Shanghai during the Level 1 pandemic response. In contrast, AH was less reduced in Guangzhou during the same period and increased in Beijing owing to extended central heating use in winter. AH decreased more in urban centers and the change in AH varied in terms of urban land use between cities and periods. Although UHI changes during the COVID-19 pandemic cannot be entirely attributed to AH changes, the considerable reduction in AH is an important feature accompanying the weakening of the UHI.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.3390/EN15249490", "year": 2022, "title": "One-Year Monitoring of a Ground Heat Exchanger Using the In Situ Thermal", "abstract": "The use of renewable energies, and of geothermal energy in particular, is increasingly being applied in Germany and Europe for the development of new residential districts. The use of geothermal borehole heat exchangers (BHE), in combination with ground-source heat pumps (GSHP), represents an important part of shallow geothermal systems, which are used, among other systems, in urban areas due to their small space requirements. Over the course of planning BHE systems, performance must be determined via the parameters of thermal conductivity, thermal capacity, undisturbed ground temperature, and borehole thermal resistance. These can be identified by the experimental approach known as thermal response testing (TRT). The thermal parameters change due to the influences of the seasonal temperature fluctuations that take place in the ground. In this paper, a pilot double-U BHE heat exchanger field with a depth of 120 m was investigated from this perspective. TRT was carried out using monthly measurements taken over the period of one year using an electrically powered mobile TRT device. The evaluation of the individual tests was carried out using the line-source, moving-line-source, and cylinder-source theories. Our results show that the season in which TRT was implemented had an influence on the determined thermal parameters, with better thermal conditions being obtained in winter months. This is especially visible for thermal conductivity, with monthly deviations of 0.1 W/(mK), independent of the evaluation approaches used.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.AOSL.2023.100409", "year": 2023, "title": "Recent urbanization increases exposure to humid-heat extreme events over populated regions of China", "abstract": "Extreme-heat research has largely focused on dry heat, while humid heat, which presents a major societal impact, especially on human health, remains relatively understudied. Previous studies have revealed that a wet-bulb temperature (TW) of 35 C marks our upper physiological limit, and much lower values also have serious health impacts. Our evaluations from observations showed that the daily maximum TW values over China have been scarcely reported above 35 C, but humid-heat extreme days of TW above 30 C have been reported each year during the past four decades, being mainly centered over the highly populated regions, including East China, South China, and the Sichuan basin. Further analyses indicated that the recent rapid urbanization process in China has amplified the societal impacts of humid-heat extremes, and land exposure to humid heat over urban regions is expected to increase at a faster rate than other regions of China. This suggests increasing risks of humid-heat extremes on human health in big cities of densely populated regions due to rapid urbanization. As indicated here, the population of China has become increasingly exposed to such extremes, with a strong increasing tendency of about 3100 persons per day per year since 2000.\n\n, , , . , 35 C, , . , 35 C, 30 C, , , ., , , . , 2000, 3100.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.RSASE.2023.101049", "year": 2023, "title": "Geospatial and statistical analysis of urban heat islands and thermally vulnerable zones in Bangalore and Hyderabad cities in India", "abstract": "Urban Heat Island (UHI) effects caused by urbanization and associated anthropogenic activities have adverse environmental and social impacts. The social impacts of UHIs on Indian cities are not well documented. To fill this void, the current paper examines the spatial variation of the UHI effects on the populations of two Indian cities: Bangalore and Hyderabad. Land Surface Temperature (LST) data for the past two decades is obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor to analyse the spatial and temporal variation of the thermal environment of the cities. The regions experiencing different levels of UHI effects within the cities, along with the population in these zones, are identified in the study. The average UHI intensity for the past two decades in Bangalore and Hyderabad is found to be 1.9 C and 2.44 C, respectively. The UHI intensity in Bangalore and Hyderabad is found to be increasing annually at a rate of 0.040 C per year and 0.033 C per year, respectively. Around 1 million people in Bangalore and 1.8 million people in Hyderabad are inhabitants of the high temperate zone, experiencing an average LST of 3.14 C and 3.55 C higher than the rest of the population, respectively. The study emphasizes the need for regionally scaled UHI mitigation strategies and identifies the most vulnerable regions within the study area to prioritize mitigation strategies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.JDEVECO.2019.02.001", "year": 2019, "title": "Intensive and extensive margins of mining and development: Evidence from Sub-Saharan Africa", "abstract": "What are the economic consequences of mining in Sub-Saharan Africa? Using a panel of 3,635 districts from 42 Sub-Saharan African countries for the period 1992 to 2012 we investigate the effects of mining on living standards (measured by night-lights and household/cohort characteristics from Demographic and Health Surveys) and public service provisions (from Afrobarometer). Night-lights increase in mining districts when mineral production expands (intensive margin), but large effects are mainly associated with new discoveries and new production (extensive margin). We identify the effect by carefully choosing feasible but not yet mined districts as a control group. In addition, we exploit first, single-first, giant and major discoveries as exogenous news shocks. Mines in Africa exhibit enclave characteristics as we find little evidence of significant spillovers to other districts.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2021.01.056", "year": 2021, "title": "MCDM and GIS based modelling technique for assessment of solar and wind farm locations in India", "abstract": "In the recent past, various factors have led to an increase in the use of renewable energy sources, among which, the depleting fossil fuel reserves, increasing fuel prices, and rising environmental concerns are the most prominent. With this increasing reliance on renewable energy sources, a proper assessment of the suitable sites becomes necessary for the optimum utilization of these resources. The present study investigates the spatial suitability of the solar and wind farms locations in India based on the technical, economic, and socio-environmental perspectives. The analysis is performed with the coupled use of the Geographical Information System (GIS) and Multi-Criteria Decision Making (MCDM) approaches. Analysis of present research work shows that 4.13% of the study area (133,874 km2) is highly suitable for the deployment of solar plants while 0.91% of the total area (29,457 km2) is highly suitable for the wind farms. The study further concludes that the Rajasthan state in India has the highest suitable land for the installation of solar plants (20,881 km2) as well as wind farms (6323 km2). The proposed model can be used for the development of policies related to renewable energy resources and the assessment of suitability of already sanctioned projects.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ESR.2022.100972", "year": 2022, "title": "Making use of the complementarity of hydropower and variable renewable energy in Latin America: A probabilistic analysis", "abstract": "Latin America is one of the regions most vulnerable to the effects of climate variability on hydropower generation. Hydropower is the backbone of the Latin-American power system and a key technology for ensuring low-carbon power generation in the region. Despite its importance, our understanding of the impact and likelihood of seasonal variability and of long-term phenomena such as the El Nino Southern Oscillation (ENSO) on hydropower is limited. There is an essential need to understand how likely these effects are and to identify measures to counterbalance them. A combination of wind, solar, and hydropower offers the potential to mitigate the impact of climate variability on renewable power generation and thus improve its reliability. Here we present a modeling framework to quantify the potential benefits of such combination. The modeling framework relies on a meteorological reanalysis dataset, large-scale renewable power generation models, and statistic models. We consider the countries with the largest hydropower capacity in the region, namely Argentina, Brazil, Colombia, Mexico, and Venezuela. We examine whether the probability of a production deficit is reduced when all renewable resources are combined compared to a scenario based solely on hydropower, especially during droughts. The approach presented allows for the first time an in-depth analysis of the benefits of a combined wind, solar, and hydropower-based power generation under different geographical conditions in altered ENSO phases. Our results suggest thatdepending on the country and the percentilethe hydropower generated during drought ENSO phases could be up to 50% lower than that during neutral phases. The countries most affected are Colombia and Venezuela, while the reduction is somewhat less severe in Argentina, Brazil, and Mexico. Combining hydropower with variable renewable energy (VRE) offers the potential to reduce the risk of a power deficit during the 10th percentile of the driest months of the year, both in drought and neutral phases. Argentina is the country with the most effective combination of resources to mitigate a power deficit, as each MW of installed VRE generates 0.218 GWh of additional power. It is followed by Brazil and Mexico with 0.185 GWh per MW of VRE and by Venezuela and Colombia with 0.1280.098 GWh/MW of VRE, respectively. These results can contribute to informing future decisions on capacity planning and regional transmission grids.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.150394", "year": 2022, "title": "Simulating the cumulative effects of potential open-pit mining and climate change on streamflow and water quality in a mountainous watershed", "abstract": "Land use and climate change effects on water quality and water quantity are well documented globally. Most studies evaluate individual factors and effects, without considering the interrelationships between land use, climate, water quality, and water quantity. This study provides an integrated assessment of the cumulative effects of climate change and potential open-pit coal mining on streamflow and water quality in the Oldman River Basin, Alberta, Canada. A hydrological model was developed that incorporates estimates of future selenium loading, water use, and projected changes in air temperature and precipitation to evaluate changes in water quantity and quality. Model results indicate that estimated selenium concentrations, absent any attenuation, are likely to be substantially above most water quality guidelines and strong reliance on mitigation technologies would be required to maintain adequate water quality in the watershed if mine development were to take place. Streamflow is sensitive to changes in climatic conditions, and modelling results suggest there are likely to be increases in winter flow, earlier peak flow, and reductions in flow during the summer and fall months under the climate change scenarios. These changes can have direct impacts on the degree of selenium dilution and more generally on aquatic habitat, ecosystem health, and socioeconomic needs. This study highlights that water management decisions may mis-evaluate the risks and tradeoffs of future mine development if they fail to adequately consider climate change and changing streamflow regimes and their indirect effects on water quality.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ENERGY.2019.04.128", "year": 2019, "title": "The impact of climatic extreme events on the feasibility of fully renewable power systems: A case study for Sweden", "abstract": "Long term time series of variable renewable energy (VRE) generation and electricity demand (load) provide important insights into the feasibility of fully renewable power systems. The coverage of energy statistics is usually too short or the temporal resolution too low to study effects related to interannual variability or the impact of climatic extreme events. We use time series simulated from climate data to assess the frequency, duration, and magnitude of extreme residual load events of two fully renewable power scenarios with a share of VRE generation (wind and solar PV) of about 50% for the case of Sweden. We define residual load as load wind PV nuclear generation. Extreme residual load events are events that exceed the balancing or ramping capacities of the current power system. For our analysis, we use 29 years of simulated river runoff and wind and PV generation. Hourly load is derived from MERRA reanalysis temperature data by applying statistical models. Those time series are used along with historic capacity and ramping restrictions of hydro and thermal power plants in an optimization model to minimize extreme residual load events. Our analysis shows that even highly flexible power systems, as the Swedish one, are affected by climatic extreme events if they increase their VRE shares. Replacing current nuclear power capacities by wind power results on average in three extreme residual load events per year that exceed the current power system's flexibility. Additional PV generation capacities instead of wind increase the number of extreme residual load events by about 4%, as most events occur during the winter month when solar generation is close to zero and thus not able to counterbalance low wind events. Contrarily, overproduction and the need to curtail VRE generation become more pressing with higher shares of PV. In the discussion we highlight measures that could provide additional balancing capabilities to cope with the more frequent and severe residual load events in a fully renewable power system with high shares of VRE generation.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1038/S41560-021-00784-Y", "year": 2021, "title": "The albedo-climate penalty of hydropower reservoirs", "abstract": "Hydropower emits less carbon dioxide than fossil fuels but the lower albedo of hydropower reservoirs compared to terrestrial landscapes results in a positive radiative forcing, offsetting some of the negative radiative forcing of hydroelectricity generat ion. The cumulative effect of this lower albedo has not been quantified. Here we show, by quantifying the difference in remotely sensed albedo between globally distributed hydropower reservoirs and their surrounding landscape, that 19% of all investigated hydropower plants required 40 years or more for the negative radiative forcing from the fossil fuel displacement to offset the albedo effect. The length of these break-even times depends on the specific combination of climatic and environmental constraints, power plant design characteristics and country-specific electricity carbon intensities. We conclude that future hydropower plants need to minimize the albedo penalty to make a meaningful contribution towards limiting global warming.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ISPRS-ARCHIVES-XLIV-M-3-2021-83-2021", "year": 2021, "title": "GEOSPATIAL ASSESSMENT FOR PLANNING A SMART ENERGY CITY USING ROOFTOP SOLAR PHOTOVOLTAIC IN BANDUNG CITY, INDONESIA.", "abstract": "Abstract. Increasing the production of clean and environmentally friendly energy has become one of the world agendas as a strategic effort in dealing with long-term climate change. Seeing the potential of the energy produced, the ease in the installation process, with the small risk of harm generated, solar energy has received significant attention from many countries in the world. The potential for solar energy in Indonesia alone reaches 207 GWp, but only 145.81 MWp has been utilized. Currently, the Indonesian government has set a target to build a Solar Power Plant capacity in 2025 of 6.5 GWh. Urban areas are areas with higher energy demand than rural areas, but the availability of vacant land in urban areas is very minimal for installing solar power plants. Therefore, rooftop solar PV(Photovoltaic) can be a solution in dense areas such as cities. Good planning by looking at the potential resources and energy needs in spatial is needed to manage and utilize energy optimally and sustainably in urban areas. This study aims to develop a geospatial assessment for plan smart energy city that uses rooftop solar PV's potential energy in every building that is effective and efficient. The novelty in the analysis of the distribution of the potential for rooftop solar PV development in urban areas integrates meteorological and spatial aspects and socio-economic aspects. Integration of multi-dynamic spatial data uses in determining the rooftop solar PV construction location, such as meteorological data for solar energy potential, increasing energy needs of each building, and socio-economy data. The data source used comes from statistical data and remote sensing data. The analysis will be carried out temporally (2008, 2013, and 2018) to see the pattern of changes in aspects used in a certain period so that the development plan can be carried out more optimally. This research's output is the formation of a priority analysis of solar PV rooftop construction in urban areas, especially the city of Bandung. The result of energy can also produce by the construction of rooftop solar PV in a potential area. This research is expected to be utilized by policymakers to develop renewable energy in the city of Bandung and increase community participation in switching to renewable energy.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JOULE.2020.11.015", "year": 2020, "title": "Global atlas of closed-loop pumped hydro energy storage", "abstract": "The difficulty of finding suitable sites for dams on rivers, including the associated environmental challenges, has caused many analysts to assume that pumped hydro energy storage has limited further opportunities to support variable renewable generation. Closed-loop, off-river pumped hydro energy storage overcomes many of the barriers. Small (square km) upper reservoirs are typically located in hilly country away from rivers, and water is circulated indefinitely between an upper and lower reservoir. GIS analysis of high resolution global digital elevation models was used to determine economically feasible closed-loop scheme locations outside protected and urban areas. This search identified 616,000 potential storage sites with an enormous combined storage potential of 23,000 TWh. This is two orders of magnitude more than required to support large fractions of renewable electricity, allowing flexible site selection. Importantly, the resource is widely distributed to effectively support large-scale solar and wind deployment for electrical grid decarbonization.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1088/2515-7620/AC40F1", "year": 2021, "title": "Direct impact of solar farm deployment on surface longwave radiation", "abstract": "Abstract\r\n \r\n Motivated by a previous study of using the Moderate Resolution Imaging Spectroradiometers (MODIS) observations to quantify changes in surface shortwave spectral reflectances caused by six solar farms in the southwest United States, here we used a similar method to study the longwave effects of the same six solar farms, with emphases on surface emissivities and land surface temperature (LST). Two MODIS surface products were examined: one relying on generalized split-window algorithm while assuming emissivities from land cover classifications (MYD11A2), the other based on Temperature Emissivity Separation algorithm capable of dynamically retrieving emissivities (MYD21A2). Both products suggest that, compared to adjacent regions without changes before and after solar farm constructions, the solar farm sites have reduced outgoing radiances in three MODIS infrared window channels. Such reduction in upward longwave radiation is consistent with previous\r\n in situ\r\n measurements. The MYD11A2 results show constant emissivities before and after solar farm constructions because its land type classification algorithm is not aware of the presence of solar farms. The estimated daytime and nighttime LST reduction due to solar farm deployment are 14K and 0.20.9K, respectively. The MYD21A2 results indicate a decrease in Band 31 (10.7811.28\r\n \r\n m) emissivity up to 0.01 and little change in Band 32 (11.7712.27\r\n \r\n m) emissivity. The LST decreases in the MYD21A2 is slightly smaller than its counterpart in the MYD11A2. Laboratory and\r\n in situ\r\n measurements indicate the longwave emissivity of solar panels can be as low as 0.83, considerably smaller than MODIS retrieved surface emissivity over the solar farm sites. The contribution of exposed and shaded ground within the solar farm to the upward longwave radiation needs to be considered to fully explain the results. A synthesis of MODIS observations and published\r\n in situ\r\n measurements is presented. Implication for parameterizing such solar farm longwave effect in the climate models is also discussed.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.31590/EJOSAT.763866", "year": 2020, "title": "Determination of the Suitable Areas for The Investment of the Wind Energy Plants (WEP) in Osmaniye Using Analytical Hierarchy Process (AHP) and \u2026", "abstract": "Renewable energy sources are considered as clean energy sources. They have a much lower environmental impact than other energy sources. Among the renewable energy sources, the wind is an important energy source. In many countries the wind power production is so popular and many alternative research techniques related to wind energy are applied. Wind energy comes to the forefront today due to the increasing population of countries and the increase in energy needs. In our country the studies about the renewable energy has evolved rapidly over the past decade. The cost of initial installation of Wind Energy Plants (WEP) is high and they can only be installed if certain conditions are met. Site selection for wind turbine installation is not a technical process only, also a complex process is necessary for involving social, economic, physical and environmental sanctions. Therefore, site selection of wind energy plants is a very complex spatial decision problem for decision makers. For the different site selection studies multi criteria evaluation methods are often used. In the study, potential WEP investment areas of Osmaniye province were determined by using, Geographical Information Systems (GIS), Analytic Hierarchy Process (AHP) method and remote sensing. The criteria selected according to the general characteristics of the study area were combined with ArcGIS software using the weight values obtained with AHP and suitable areas for the WEP installation were determined. The land suitability index maps for the WEP siting is created in the ArcGIS program. The weighted Sum analysis of the Spatial Analyst Tool is used for this purpose. According to the results, 14.30% of the study area are suitable, 15.84% are moderate suitable and 69.86% are not suitable for wind energy plant siting", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/W13050716", "year": 2021, "title": "Impact of Prospective Climate Change Scenarios upon Hydropower Potential of Ethiopia in GERD and GIBE Dams", "abstract": "Ethiopia is growing fast, and the country has a dire need of energy. To avoid environmental damages, however, Ethiopia is looking for green energy polices, including hydropower exploitation, with large water availability (i.e., the Blue Nile, the greatest tributary of Nile river). Besides other dams on the Omo river, the GIBE family, Ethiopia is now building the largest hydropower plant of Africa, the GERD (Grand Ethiopian Renaissance Dam), on the Blue Nile river, leading to tensions between Ethiopia, and Egypt, due to potentially conflictive water management. In addition, present and prospective climate change may affect reservoirs operation, and this thereby is relevant for downstream water users, population, and environment. Here, we evaluated water management for the GERD, and GIBE III dams, under present, and future hydrological conditions until 2100. We used two models, namely, Poli-Hydro and Poli-Power, to describe (i) hydrological budget, and flow routing and (ii) optimal/maximum hydropower production from the two dams, under unconstrained (i.e., no release downstream besides MIF) and constrained (i.e., with fair release downstream) simulation. We then used climate change scenarios from the reports CMIP5/6 of the Intergovernmental Panel on Climate Change (IPCC) until 2100, to assess future hydropower production. Our results demonstrate that the filling phase of the GERD, particularly critical, have optimal filling time of 5 years or so. Stream flows at GERD could be greater than the present ones (control run CR) at half century (20502059), but there could be large decrease at the end of century (20902099). Energy production at half century may increase, and then decrease until the end of century. In GIBE III discharges would increase both at half century, and at the end of century, and so would energy production. Constrained, and unconstrained simulation provide in practice similar results, suggesting potential for shared water management in both plants.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/B978-0-323-85527-3.00018-2", "year": 2022, "title": "Meteorological assessment of coupled wind\u2013solar power generation regimes in Spain", "abstract": "Wind and solar power generation exhibit variability over a wide range of time scales. This intermittency is probably the most important drawback in terms of increasing the participation of these energies in the power systems. A proper distribution of wind and solar plants in a region has been reported to be a successful way to reduce the fluctuations in the aggregated-power supply. This reduction is enhanced when the allocation of the renewable power capacity makes use of the spatiotemporal variability of the wind and solar energy resources. Indeed, by exploiting the spatial and temporal complementarity of the wind and solar energy resources, below-normal power generation in some areas can be balanced with above-normal generation in other areas at given times, thereby reducing the fluctuations in the power generation. The main objective of this study is to assess the extent to which the wind and solar power generation is coupled in Spain on daily time scales, as well as to analyze their associated weather patterns. A byproduct of this study is the identification of coupled windsolar power generation modes exhibiting balancing. To this end, gridded daily solar and wind power generation time series, spanning a period of 10 years (200110) and covering Spain, are used as input of a clustering algorithm. As a result, coupled power regimes (CPRs) are obtained. For each of these CPRs, the spatial distribution of the wind and solar power generation and the associated synoptic weather patterns are evaluated. The CPRs are interpreted on the light of these weather patterns and the topographic features of the study region. The results reveal the existence of six-coupled modes for winter and four for the rest of the seasons, with only some of these modes being relevant regarding the balancing between the wind and solar power generation. A marked seasonality of the balancing strength as well as their spatial and temporal covering is observed. The most relevant balancing is detected during autumn, followed by winter, spring, and, lastly, summer. It is found that all the balancing modes, except the summer ones, are associated with the presence of a positive/negative (alternating) center of pressures anomalies located, roughly, over Ireland. The interaction of the resulting wind circulation with the existing topographical features explains the balancing patterns. The results reported in this study may have important consequences regarding the optimal spatial allocation of new renewable power plants over Spain. Nevertheless, the practical usefulness of the results implies the use of some daily energy storage system.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.4209/AAQR.200664", "year": 2021, "title": "Effects of lockdown due to the COVID-19 pandemic on air quality at Latin America's largest open-pit coal mine", "abstract": "ABSTRACT Particulate matter (PM) is the main pollutant produced by open-pit mining operations, and its emission into the atmosphere is strongly associated with adverse health effects in the surrounding communities. The objective of this study was to evaluate the effects of the COVID-19-related lockdown on the PM concentrations in the North, Central, and South Zones of Cerrejon, Colombia, the largest open-pit coal mine in Latin America. To compare the levels before and during the emergency shutdown, we analyzed both the ground-based daily PM10 and PM2.5 data and the satellite (Terra/Aqua MODIS)-based daily aerosol optical depth (AOD) values from March 6 through April 13, 2020. The average PM10 concentrations in the North and South Zones, in contrast to those observed at other global monitoring sites, increased by 1338% and 47%, respectively, although they decreased by 2631% in the Central Zone, between the pre-lockdown and lockdown periods. Furthermore, during the latter, the daily PM2.5 levels in the South Zone rose by up to 43%, and we found higher AOD values ( 0.4) over the Central and South Zones as well as significant AOD-contributing loads upwind and downwind of the coal production pits. Finally, the increases in humidity and temperature ( 3.5% and 0.3 K, respectively), decrease in planetary boundary layer height ( 0.11 km), wind field variability, and rural biomass burning events shaped the spatial-temporal behavior of the PM in this region, and changes in meteorology and external sources nearly offset the reduction in emissions from mining activities. These results establish a baseline for developing future regulations and mitigation plans.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/S41597-022-01331-4", "year": 2022, "title": "A solar energy desalination analysis tool, sedat, with data and models for selecting technologies and regions", "abstract": "There is interest for desalination technologies powered by solar energy as arid areas are typically bestowed with good solar potential. In response to a US DOE call for solar desalination analysis tools, we developed an open-source solar energy desalination analysis tool, sedat, for techno-economical evaluation of desalination technologies and selection of regions with the highest potential for using solar energy to power desalination plants. It is expected that this software will simplify the planning, design, and valuation of solar desalination systems in the U.S. and worldwide. Sedat uses Dash for integrating various layers of large volumes of GIS data with Python-based models of solar energy generation and desalination technologies. It derives time-series of energy generation and water production, with details of plant performance and suggestions for improving the solar-desalination coupling. This paper summarizes the various phases of the tools development, presents example results showing the potential, under multiple objectives, of solar desalination in parts of the U.S. southwest, and discusses method details that would be useful for future model development.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RSER.2021.111900", "year": 2022, "title": "Potential assessment of photovoltaic power generation in China", "abstract": "Accurate assessment of the photovoltaic (PV) power generation potential in China is important for the reduction of carbon emission intensity and the achievement of the goal of Carbon Neutral. This study used a PV power generation potential assessment system based on Geographic Information Systems (GIS) and Multi-Criteria Decision Making (MCDM) methods to investigate the PV power generation potential in China. Firstly, the high spatial-temporal resolution and high-quality ERA5 data and related technical, geographic, and social factors were used to assess the theoretical power generation and land suitability of PV power generation. Then, the theoretical power generation and land suitability were comprehensively considered to evaluate the PV power generation potential of China in 2015. The results showed that the average suitability score of land in China is 0.1058 and the suitable land for PV power generation is about 993,000 km2 in 2015. The PV power generation potential of China is 131.942 PWh, which is approximately 23 times the electricity demand of China in 2015. The spatial distribution characteristics of PV power generation potential mainly showed a downward trend from northwest to southeast. Meanwhile, there were clear spatial dislocations between the PV power generation potential and the population distribution and electricity demand in China. In areas that accounting for about 75% of the PV potential, population and electricity demand only accounted for about 16% of the total population and total electricity demand in China. Besides, the degree of tapping PV potential in China is not high, and the installed capacity of most provinces in China accounted for no more than 1% of the capacity potential, especially in the PV potential-rich areas.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1038/S41598-018-30489-4", "year": 2018, "title": "Projected Increase in Hydropower Production in India under Climate Change", "abstract": "Hydropower is a valuable renewable energy resource in India, which can help in climate change mitigation and meet the increasing energy demands. However, the crucial role of climate change on hydropower production in India remains unexplored. Here using the observations and model simulations, we show that seven large hydropower projects experienced a significant (p-value ", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/RS14122796", "year": 2022, "title": "Multi-Criteria Assessment for City-Wide Rooftop Solar PV Deployment: A Case Study of Bandung, Indonesia", "abstract": "The world faces the threat of an energy crisis that is exacerbated by the dominance of fossil energy sources that negatively impact the sustainability of the earths ecosystem. Currently, efforts to increase the supply of renewable energy have become a global agenda, including using solar energy which is one of the rapidly developing clean energies. However, studies in solar photovoltaic (PV) modelling that integrates geospatial information of urban morphological building characters, solar radiation, and multiple meteorological parameters in low-cost scope have not been explored fully. Therefore, this research aims to model the urban rooftop solar PV development in the Global South using Bandung, Indonesia, as a case study. This research also has several specific purposes: developing a building height model as well as determining the energy potential of rooftop solar PV, the energy needs of each building, and the residential property index. This study is among the first to develop the national digital surface model (DSM) of buildings. In addition, the analysis of meteorological effects integrated with the hillshade parameter was used to obtain the solar PV potential value of the roof in more detail. The process of integrating building parameters in the form of rooftop solar PV development potential, energy requirements, and residential property index of a building was expected to increase the accuracy of determining priority buildings for rooftop solar PV deployment in Bandung. This study shows that the estimated results of effective solar PV in Bandung ranges from 351.833 to 493.813 W/m2, with a total of 1316 and 36,372 buildings in scenarios 1 and 2 being at a high level of priority for solar PV development. This study is expected to be a reference for the Indonesian government in planning the construction of large-scale rooftop solar PV in urban areas to encourage the rapid use of clean energy. Furthermore, this study has general potential for other jurisdictions for the governments focusing on clean energy using geospatial information in relation with buildings and their energy consumption.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1002/2018EF000809", "year": 2018, "title": "The Water-Energy Nexus of Hydraulic Fracturing: A Global Hydrologic Analysis for Shale Oil and Gas Extraction", "abstract": "Shale deposits are globally abundant and widespread. Extraction of shale oil and shale gas is generally performed through water-intensive hydraulic fracturing. Despite recent work on its environmental impacts, it remains unclear where and to what extent shale resource extraction could compete with other water needs. Here we consider the global distribution of known shale deposits suitable for oil and gas extraction and develop a water balance model to quantify their impacts on local water availability for other human uses and ecosystem functions. We find that 31-44% of the world's shale deposits are located in areas where water stress would either emerge or be exacerbated as a result of shale oil or gas extraction; 20% of shale deposits are in areas affected by groundwater depletion and 30% in irrigated land. In these regions shale oil and shale gas production would likely compete for local water resources with agriculture, environmental flows, and other water needs. By adopting a hydrologic perspective that considers water availability and demand together, decision makers and local communities can better understand the water and food security implications of shale resource development.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2023.01.079", "year": 2023, "title": "Identification of potential locations for small hydropower plant based on resources time footprint: A case study in Dan River Basin, China", "abstract": "Small hydropower has attracted extensive interest as a clean technology. This study first identified possible sites of small hydropower plants with estimated capacity, and then utilized resources time footprint as a novel way to evaluate the impact of small hydropower plants on the aspects of materials, CO2, labor, and land. Resources time footprint is a sustainability indicator that uses a uniform time unit (years). It assesses whether the usage of resources exceeds the amount allocated to different people and generations. The smaller the value of resources time footprint, the more environmentally friendly is the process. Preferential locations for small hydropower in Dan River were specified, with a potential capacity ranging from 273 to 1175 kW. Resources time footprint of copper is 8.947.3 times as large as that of steel. Resources time footprint of CO2 emissions is much smaller than that of other aspects, revealing that small hydropower has a great potential to mitigate the greenhouse effect. The overall resources time footprint decreases with an increase in the installed capacity. The methodology proposed in this study can be used to identify the ideal locations for setting up small hydropower plants in other regions as well.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SETA.2023.103038", "year": 2023, "title": "Wind power potential over India using the ERA5 reanalysis", "abstract": "Indias growing installed capacity for electricity generation faces demands from surging domestic consumption, national energy security and obligations under climate change accords. It is exigent to increase focus on renewables as their share in net electricity generated may reach 22 % by 2030, against the goal of 40 % from non-fossil fuels by 2030 as pledged under the Paris Agreement. Wind energy is preferable at higher levels of renewables due to favourable capacity factors. Prior investigations necessary to develop wind farms are better achieved through reanalysis datasets than satellite-derived wind products, which are temporarily coarse and limited to off-shore regions. In this study, we estimate wind power potential at 100 m level over the Indian domain using data from the ERA5 reanalysis for 19792018 through the Weibull mixture distribution. Our findings indicate that Indias mainland (off-shore) regions have a wind power potential of nearly 7.2 TW (18.4 TW), considering just 3 % of the available area. Further, up to 53 TW is available for exploitation over sparsely vegetated areas, which extend up to 25 % of Indias mainland. Future efforts for exploiting wind energy should focus on the availability of wind resources and their proximity to energy-hungry regions.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.30499/IJG.2022.341806.1425", "year": 2023, "title": "Searching suitable areas for installing solar panels in Golestan province using observation, ERA5 and GEOS-5 data", "abstract": "Due to its special geographical location, Iran has a high potential for the use of renewable energy. At present, electricity in Golestan province is supplied from Neka and Aliabad Katoul power plants, which due to the increase in population, it is necessary to build new power plants. In this study, the annual and monthly solar energy atlas maps were prepared using solar radiation data recorded in meteorological stations, GEOS-5, and ERA5 data to help decision-makers to locate suitable places for the establishment of solar power plants in different parts of Golestan province. In recent years, along with other kinds of data, the use of reanalysis data of numerical forecasting models has become popular, especially for those areas which are not covered by satellites and also to fill data gaps. To reach the goal of this study, statistical gaps in meteorological station data in the selected period (from 2014 to 2020) have been filled using the ratio method; then RUN-TEST method has been used to test the homogeneity of the data. To check the accuracy of data, the Absolute Error (MAE), Mean Bias Error (MBE), Mean Square Error (RMSE), and Coefficient of Determination (R2) between actual radiation values and GEOS-5 data as well as ERA5 data were calculated. The results show that although the accuracy varies across different locations and periods in the province, in general both outputs are suitable for estimating solar radiation and the correlation coefficients in both methods are significant at 95% confidence level. Annual solar radiation zoning of Golestan province indicates the range of annual radiation varies from 1089 kW/m2/year in forested mountainous areas up to 1800 kW/m2/year in the southwestern heights where the average of total annual radiation is 1485 kW/m2/year. The region of maximum annual radiation is located in the southwestern heights of Golestan province. In this area, solar rays strike the ground more vertically than in the other parts of the province, and also it has a semi-arid and cold mountainous climate. Moreover, the northeastern region of Golestan province has suitable annual solar radiation (1500 to 1600 kW/m2) due to its semi-arid climate and the high annual sunshine hours. The overlap map of the received radiation of Golestan province with its topography shows the appropriate quality of zoning in this area. The results of this overlap map indicate that the annual solar radiation is minimum in forested and wet areas and is maximum in semi-arid and low rainfall areas of the province. Therefore, the northeastern and southwestern regions of Golestan province have a good potential for utilizing solar energy.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SCITOTENV.2023.162979", "year": 2023, "title": "Assessment of solar energy potential in China using an ensemble of", "abstract": "Development of solar energy is one of the key solutions towards carbon neutrality in China. The output of solar energy is dependent on weather conditions and shows distinct spatiotemporal characteristics. Previous studies have explored the photovoltaic (PV) power potential in China but with single models and low-resolution radiation data. Here, we estimated the PV power potential in China for 20162019 using an ensemble of 11 PV models based on hourly solar radiation at the resolution of 5 km retrieved by the Himawari-8 geostationary satellite. On the national scale, the ensemble method revealed an annual average PV power potential of 242.79 kWh m2 with the maximum in the west (especially the Tibetan Plateau) and the minimum in the southeast (especially the Sichuan Basin). The multi-model approach shows inter-model spreads of 6 %7 % distributed uniformly in China, suggesting a robust spatial pattern predicted by these models. The seasonal variation in general shows the largest PV power generation in summer months except for Tibetan Plateau, where the peak value appears in spring because the high cloud coverage dampens the regional solar radiation in summer. On the national scale, the deseasonalized PV power potential shows a high correlation with cloud coverage (R2 = 0.71, p ", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.EXIS.2022.101136", "year": 2022, "title": "Comparative capacity of global mining regions to transition to a post-mining future", "abstract": "This paper focuses on the ability of regions where mining is concentrated to adapt to closure given the regional assets and the complexities of their association with declining production of various commodities. We propose a conceptual framework to examine the relative capacity of global regions to transition and prosper post-mining by analysing contextual factors and characterising the mining footprint in the regions. Public sources of geo-locatable data are used to define and locate mining regions in transition and to assess the interacting mining and contextual factors that enable or constrain their capacity to transition. The data-driven examination illuminates the comparative capacity of global regions confronting the challenge of mine closure. It engages with themes from regional studies, mine closure and transition studies to consider multidimensional aspects of regional transition.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.REF.2023.06.009", "year": 2023, "title": "Improving Solar PV Prediction Performance with RF-CatBoost Ensemble: A Robust and Complementary Approach", "abstract": "Although solar energy is renewable, environmental conditions can make it unpredictable, which makes it difficult to maintain a consistent supply of electricity. Accurate solar forecast techniques are essential to overcome this. Therefore, an efficient model for predicting solar irradiance and PV power output is presented in this study. The suggested model is especially designed for Agartala city in Tripura, India, where the installed capacity of Grid Interactive Solar Power is extremely low. The proposed model for solar irradiance prediction involves utilizing a combination of the Random Forest and CatBoost algorithms. The model is developed using 10 years of solar data and other relevant meteorological parameters with a 1-hour interval and assessed at various stages to make long-term monthly predictions. In addition, we compared this model to other existing models for solar irradiance prediction. The study showcased the efficacy of Random Forest and CatBoost algorithms when utilized individually and as an ensemble. The results demonstrate the effectiveness of the Random Forest and CatBoost ensemble, with an impressive accuracy improvement of 6% and an R2-score of 86%. Additionally, in terms of RMSE and MAE, the model demonstrates superior performance with lower values of 83.8466 and 45.4011, respectively confirms to the proposed model's viability and suitability for long-term solar radiation and PV power predictions.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.RESCONREC.2023.106939", "year": 2023, "title": "Comprehensive regionalization and potential water crisis for solar power development in arid and semi-arid regions of northwest China", "abstract": "Large-scale water scarcity and geo-environment disparity in arid and semiarid regions of northwest China may be the limitations of ambitious solar energy development. This study quantified water-energy conflict for photovoltaic (PV) and concentrated solar power (CSP) both in China and in this region, and assessed development suitability of solar power at municipal level. The results show that arid provinces faced intense water-energy conflict, 22.8 and 22.9 times higher than humid provinces for PV and CSP respectively. Enormous spatial differences in water-energy conflict existed in the region (PV, 1.5655.5; CSP, 2.21099.0). Considering both water-energy conflict and geo-environment, the region was divided into development zone (including water-surplus and water-deficit subzone) and limited zone. It is indicated that 58.666.4% of northwest China need to increase available water resources to meet demands for future solar energy development. This research perspective that solar power development should focus on water constraints in northwest China, together with zoning methodology outlined in this study, could provide a valuable reference for its development in arid regions or countries globally.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3389/FEVO.2023.1127028", "year": 2023, "title": "A new pattern to quantitatively evaluate the value of ecosystem services", "abstract": "Introduction\r\n Open-pit coal mining could disrupt the ecosystem and lead to the loss of service values for the ecosystem through direct occupation or indirect impacts on adjacent ecosystems.\r\n \r\n \r\n Methods\r\n In this research, we combined a new accounting system, gross ecosystem product (GEP), with spatialtemporal analyses to quantify the ecological variation and explore its driving factors in Pingshuo, a large-scale open-pit coal mining area in China. GEP is an aggregate accounting system that can summarize the value of provisioning, regulating, and cultural ecosystem services (ES) in a single monetary metric. The spatialtemporal approaches used in our study were known as exploratory spatial data analyses and interpretable models in machine learning. Both spatial and non-spatial data, including remote sensing images, meteorological data, and official statistics, were applied in the research.\r\n \r\n \r\n Results\r\n The results indicated the following: (i) From 1990 to 2020, the annual average growth rates of GEP decreased from 30.78 to 9.1%. Furthermore, the classified results of GEP revealed that the regions with rich ES quality rapidly reduced from 51.90 to 32.18%. (ii) Spatial correlation of GEP was significant, and the degree of spatial clustering was relatively high in the mining areas. Moreover, the mining areas also continually presented concentrated high-density and hot spot areas of GEP changes. (iii) The spatialtemporal effects were notable in the relationship between GEP and three socioeconomic factors, i.e., the mining effects, human activity intensity, and gross domestic product (GDP). (iv) The winwin development for both the economy and ecological environment in Pingshuo could be realized by restricting the annual growth rate of mining areas to between 4.56 and 5.03%.\r\n \r\n \r\n Discussion\r\n The accounting results and spatialtemporal analyses of GEP will contribute to the future regional sustainable development and ecosystem management in Pingshuo.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5558/TFC2023-016", "year": 2023, "title": "Assessing the effects of sugar maple tapping on lumber production", "abstract": "Production goals for certain stands previously used mainly to produce sugar maple (Acer saccharum Marsh.) lumber are being revised due to the growing demand for products made from maple sap. This paper therefore estimates the impacts that maple sap production may have for maple lumber production. We began by developing a model able to predict sugar maple lumber losses due to tapping for sap collection. We then used the model to simulate two management scenarios: one for timber production alone, and one for production of both lumber and maple sap in the same stand. The results suggest that the net harvested volume of lumber declines by approximately 40% in the co-production scenario, compared to the timber production scenario.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.MTENER.2023.101347", "year": 2023, "title": "0.01 to 0.5 Sun is a Realistic and Alternative Irradiance Window to Analyze Urban Outdoor Photovoltaic Cells", "abstract": "Solar cells have penetrated many cities as Building Integrated Photovoltaic (BIPV) or the energy source for standalone Internet of Things (IoT) devices. Traditionally, photovoltaic (PV) cells are evaluated using 1 sun irradiance. However, in a city, factors such as air pollution, cloudiness and cell installation orientation may attenuate the receivable solar energy. Also, the power conversion efficiency (PCE) of a PV cell is highly irradiance-dependent. Evaluating urban outdoor PV cells using 1 sun irradiance could lead to inaccurate prediction of PCE and overestimated output power in actual usage. Herein, we analyzed daytime irradiances of 11 cities located across the globe. Our results show that realistic irradiance (RI) in most cities is between 0.01 and 0.5 sun, reflecting the irradiance under a cloudy to mostly sunny sky. Under such an RI window, the PCEs of 9 different PV technologies were compared. 7 PV technologies have compromised performance. 2 PV technologies, organic and perovskite PVs, show enhanced PCE under the RI window and are favorable for urban outdoor applications. The potential of powering IoT devices by these PV technologies under sub-optimal irradiance conditions in cities is also highlighted.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1049/ICP.2023.1445", "year": 2023, "title": "Optimizing a solar-battery-plant for peak-time (9AM-10PM) operation with constant power output", "abstract": "With increasing penetration of renewable energies, dispatchable power plants are pushed out of the market. When the flexibilities to balance load and generation are depleted, new renewable systems need to be able to operate just like the fossil fuelled powerplants they replace and provide a guaranteed output. Hybrid powerplants combining a renewable energy source with storage can provide this constant power as well as associated grid services. In the case studied here, a constant power supply based on solar energy is necessary to support the island's energy demand. The goal was to find the most economic operation strategy for the energy management system and the optimal size of the solar farm and the battery system that fulfill the requirements of the underlying power purchase agreement. The chosen strategy and sizing are then tested through a 25-year simulation. The result was that the sizing of all components is coupled to the operation mode of the energy management system, and both determine the energy that can be provided to the grid. Here, the battery capacity should be slightly above 3 hours of the plant capacity resulting in operating the system at around 70% of its nominal power output in most days.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.EJRH.2023.101615", "year": 2024, "title": "Fluctuations of discharge and hydropower potential in the upper Amu Darya under the background of climate change", "abstract": "Study Region\nUpper Amu Darya (UAD).\nStudy Focus\nThe UAD has abundant hydropower potential (HP). This study focuses on the potential sites of small hydropower stations (sHPs) and explores the impact of future climate change on discharge and HP.\nNew Hydrological Insights for the Region\nThe conflict between water resources and hydropower in Central Asia is a key issue affecting regional development. Developing sHPs provides a new direction for alleviating energy shortages in Central Asia. Combining the hydrological model with the geographic information decision-making method, we have determined the potential sites for ten sHPs in the UAD and calculated the HP for each station. Based on future climate data from two shared socioeconomic pathways and four global climate models, we found that future precipitation and temperature are projected to increase, with precipitation increasing mainly in spring and winter. The average discharge will increase by 19.136.6% in the near-term (20312050) and by 29.7106.8% in the long-term (20712090). In addition, climate change has significantly increased HP in winter, and the increase of HP in relatively high altitudes is higher than that in low altitudes. This implies that the HP development prospect of UAD is broad in future, but for sHPs construction schemes, it is necessary to further consider the impact on both environment and society.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1038/S41467-023-41701-Z", "year": 2023, "title": "Carbon intensity of global crude oil trading and market policy implications", "abstract": "The energy mix transition has accelerated the need for more accurate emissions reporting throughout the petroleum supply chain. Despite increasing environmental regulations and pressure for emissions disclosure, the low resolution of existing carbon footprint assessment does not account for the complexity of crude oil trading. The lack of source crude traceability has led to poor visibility into the well-to-refinery-entrance carbon intensities at the level of granular pathways between producers and destination markets. Using high-fidelity datasets, optimization algorithms to facilitate supply chain traceability and bottom-up, physics-based emission estimators, we show that the variability in global well-to-refinery-entrance carbon intensities at the level of crude trade pathways is significant: 4.2214.1 kg-CO2-equivalent/barrel with a volume-weighted average of 50.5 kg-CO2-equivalent/barrel. Coupled with oil supply forecasts under 1.5 C scenarios up to 2050, this variability translates to additional CO2-equivalent savings of 1.56.1 Gigatons that could be realized solely by prioritizing low-carbon supply chain pathways without other capital-intensive mitigation measures.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1063/5.0128383", "year": 2023, "title": "A Preliminary Geospatial Assessment of the Rooftop Solar Photovoltaic Potential in Bandung City, Indonesia", "abstract": "The demand for energy is increasing significantly over the past few decades. Mostly, the energy is coming from fossil fuels. It should be noted that fossil energy is not environmentally friendly and non-sustainable energy. Hence, it is necessary to replace fossil energy with renewable and sustainable energy such as solar PV energy. Solar energy is one of the renewable energies that can choose to replace fossil energy sources. Urban areas are areas with higher energy requirements than rural areas, but the availability of vacant land in urban areas is very minimal to the installation of solar power plants. Hence, rooftop solar PV energy can be a solution in dense areas such as urban areas. Before installing a rooftop solar PV plant, it is necessary to investigate how much energy can be provided to meet daily needs. Furthermore, it is also essential to optimize the installation so more daily energy can be supplied. This research focuses on investigating the solar energy potential to meet the daily demand from time to time. Modeling of solar energy potential in each house is essential to determine how much energy can be provided by solar PV plants in several years. In this research, the temporal analysis is used to model the energy demand from solar PV plants. This research will integrate statistical data and remote sensing data. The availability and the demand energy of each house will be investigated thoroughly in this research. Furthermore, how much electrical energy can be supplied by solar PV rooftop is also considered in this research. This research is expected to be used by policymakers in developing renewable energy in the city of Bandung and will increase community participation in switching to renewable energy.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1038/S44172-023-00155-3", "year": 2024, "title": "Spatiotemporal management of solar, wind and hydropower across continental Europe", "abstract": "Weather climate fluctuations cause large variations in renewable electricity production, which requires substantial amounts of energy storage to overcome energy drought periods. Based on daily hydroclimatic data and information about renewable power systems covering Europe, here we quantify the complementarity in the solar-wind-hydro energy components of the continental climate system. We show that the spatiotemporal management of renewable electricity production over Europe can induce a virtual energy storage gain that is several times larger than the available energy storage capacity in hydropower reservoirs. The potential electricity production matches the consumption by spatiotemporal management of suitable shares of solar and wind power complemented with the present hydropower. While the mixed renewable energy potential varies less than anticipated at the continental scale, utilization of the complementarity requires new continental electrical transmission lines and stable international trade. We highlight that management models need to consider incentives beyond national boundaries to appropriately benefit from continental climate conditions.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.35382/TVUJS.13.6.2023.2125", "year": 2023, "title": "Assessment the Impact of Solar Panels on the Environment", "abstract": "Solar energy is a renewable energy source that is becoming increasingly popular in providing electricity for households and industrial production. Using solar panels also brings many benefits to human life. In particular, solar panels are advantageous in providing electricity to remote and isolated areas that do not have access to the national grid. However, like any other technology, solar panels also have particular environmental impacts that need to be taken into account. From reference sources, this study aims to make statistics and evaluate the impacts of solar panels on the environment. The analyzed results show that the land occupancy index of solar power is the least compared to other power sources for the power plant's life of more than 25 years.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.APENERGY.2023.121846", "year": 2023, "title": "Different photovoltaic power potential variations in East and West China", "abstract": "Photovoltaic (PV) technology can help reduce carbon emissions significantly, but its benefits may be affected by climate change. Few studies have reported on the impact of climate change on the spatial and temporal distribution of solar energy in China based on the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) models, and few have explored the rooftop PV potential. In this study, 16 CMIP6 models are used for evaluation of the inter-annual and seasonal changes of solar irradiance and PV capacity factor under low (SSP12.6), medium (SSP24.5) and high (SSP58.5) greenhouse gas emission scenarios. The effects on the variation of solar irradiance of three factors are examined: clouds, aerosol optical thickness (AOT) and specific humidity. Furthermore, the future power generation potential of rooftop PV is investigated. It is found that the solar irradiance exhibits an upward trend on national level under all the future scenarios, especially for the SSP12.6 scenario, with an increasing rate of 1.4 W m2 decade1, mainly due to a reduction in AOT. Solar irradiance increases notably in southeast China while increases little in west China, and the level for 20512060 remains lower than that for 19602014. The PV capacity factor increases in southeast China with increasing solar irradiance, with a maximum increase of about 4% compared to the average PV CF for 19602014 and the highest increasing rate being 0.37% decade1. In addition, to achieve the projected national distributed PV power generation level, >70% of the effective rooftop area needs to be utilized in 2050. This study hopes to enhance understanding of the impact of climate change on solar energy and provide recommendations for future PV planning to better achieve the long-term planetary temperature goal set by the Paris Agreement.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2023GL104825", "year": 2023, "title": "A Closer Look at the Effects of Lake Area, Aquatic Vegetation, and Double-Counted Wetlands on Pan-Arctic Lake Methane Emissions Estimates", "abstract": "Lake methane emissions are commonly upscaled from lake area, with recognition that smaller, non-inventoried lakes emit more per unit area. There is also growing awareness of the importance of lake aquatic vegetation and potential \"double-counting\" with wetlands, but lack of consensus on which is most impactful. Here, we combine high-resolution data with the comprehensive lake inventory HydroLAKES to rank these three variables based on emissions sensitivity. Including non-inventoried small lakes <0.1 km2 (+30 [range: 9.0 to 82]% change) is greatest, followed by double-counting (\u221220 [\u221211 to \u221234]%) and lake aquatic vegetation (+14 [2.7 to 43]%). Significantly, emissions from non-inventoried lakes contribute far less than the \u223c40% previously determined globally through statistical area extrapolation. We produce a first pan-Arctic estimate of lake aquatic vegetation in 1.37 million km2 of lakes, but after correcting for persistent double-counting, its net effect is to decrease emissions estimates by 9%. Thus, previous global emissions estimates are likely too high.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S12648-023-02802-Z", "year": 2023, "title": "Variation of aerosol parameters (AI, AOD) and SO2 over Indo-Gangetic basin during COVID-19 outbreaks", "abstract": "To stop the spread of COVID-19 infections, idea of complete and partial lockdowns was implemented in several countries. In the present work, variation of aerosol index (AI), aerosol optical depth (AOD) and SO2 concentration over Indo-Gangetic Basin regions (over highly polluted cities: Varanasi, Kanpur and Delhi) were analyzed to see the impact of lockdown periods during 2020. AI data were taken from satellite based ozone monitoring instrument while AOD and SO2 data were taken from moderate resolution spectroradiometer (MODIS). Lockdown periods of March, April, May and June months of 2020 were compared with the same months of 2017, 2018 and 2019. Significantly large difference in AI was observed associated with decreased value of AI during lockdown periods followed by AOD values and SO2 concentrations. All these cities of Northern India (Varanasi, Kanpur and Delhi) show significant decline in aerosol index which indicate less emissions of black carbon and other absorbing aerosol particles into the atmosphere. Trend of AI and SO2 concentration were found to be negative due to the sudden decrease in their values. Decline in the aerosol parameters (AI and AOD) and air pollutant (SO2) suggest improved air quality of the highly polluted cities of India.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2014.10.013", "year": 2015, "title": "Variation of aerosol optical properties from AERONET observation at Mt. Muztagh Ata, Eastern Pamirs", "abstract": "Using data from the ground-based remote sensing Aerosol Robotic Network (AERONET), aerosol optical properties, including aerosol optical depth (AOD), Angstrom exponent (), and volume size distribution were investigated for the period June to December 2011 at Mt. Muztagh Ata (Muztagata), Eastern Pamirs. The monthly average values of AOD (500 nm) and (440870 nm) varied from 0.08 0.02 to 0.16 0.11, and from 0.56 0.06 to 0.93 0.28, respectively. The daily AOD averages 0.14 0.07, with the maximum (0.5) occurring in August and the minimum (0.05) occurring in November. A small increase in AOD is expected with a noticeable decrease in the value. The daily averages 0.70 0.27, and most exponents are less than 1, indicating the majority of larger aerosol particles. The volume size distribution of aerosol particles shows bimodal log-normal characteristics, with a fine mode radius of 0.2 m and a coarse mode radius of 3 m. The MODIS AOD and AERONET AOD display a similar variation, while the former is always noticeably higher than the latter with a difference of 0.10.4, indicating that the MODIS data might overestimate the aerosol load. Our results indicate that high aerosol volume concentration occurs in summer with the dominance of coarse particles over Muztagh Ata. The low AOD shows a clean atmosphere in this region, revealing that it is an atmospheric background site for continental aerosol monitoring", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.20937/ATM.52858", "year": 2023, "title": "Surface shortwave cloud radiative effect of cumulus and stratocumulus-cumulus cloud types in the Caribbean area (Camaguey Cuba, 2010-2016)", "abstract": "The effects of cumulus (Cu) clouds and the combination of stratocumulus-cumulus (Sc-Cu) clouds on solar radiation at the Earths surface were evaluated at Camaguey, Cuba, during a 6-yr period (from June 2010 to May 2016). Two methods to calculate the cloud radiative effect (CRE) were employed. The first method (CREm) uses solar irradiances in cloudy conditions from actinometric observations, where cloud information was also reported by visual observation. In the second method (CRE0) surface solar irradiances were estimated for both cloudy and clear sky conditions using a 1-D radiative transfer model, and cloud optical depth (COD) retrieved from an AERONET sun-photometer as the main input. A temporal correspondence criterion between COD retrievals and actinometric observations was performed in order to classify the COD of each cloud type. After the application of this criterion, the COD belonging to the optically thin clouds was removed. Finally, 255 and 732 COD observations for Cu and Sc-Cu, respectively, were found. Results show a statistically significant difference at the 95% confidence level between CRE calculated for Sc-Cu and Cu, using both methods. Mean values of CREm and CRE0 for Cu (Sc-Cu) were 442 (390) and 460 (417) Wm2, respectively. CRE0 shows a linear relation with ln(COD), with stronger correlation at a lower solar zenith angle. The shortwave cloud effect efficiency (CEE) for the two cloud types sharply decreases with the increase of the COD value up to 20. For larger COD, the CEE is less sensitive to the increase of COD.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.JMARSYS.2013.12.008", "year": 2015, "title": "Summertime physical and biological controls on O2 and CO2 in the Australian Sector of the Southern Ocean", "abstract": "Continuous measurements of CO2 partial pressure, dissolved oxygen, and the oxygen argon ratio (O2/Ar) in surface waters, complemented by discrete observations of inorganic carbon, along a late-summer south-tonorth transect in the Australian Sector of the Southern Ocean (115E, WOCE I9S) are presented. The largest net community production (NCP, based on O2/Ar), and airsea CO2 disequilibrium (DpCO2) were found in three regions: (1) between the southern boundary of the Antarctic Circumpolar Current (63.6S) and southern extent of the Polar Front (58.6S, NCP = 30 mmol C m2 d1, pCO2 =30to50atm); (2) between the northern extent of the Sub-Antarctic Front (45.5S) and the Sub-Tropical Front (39.8S, NCP = 50 mmol C m2 d1, pCO2 =25atm); and (3) near 35S (NCP = 50 mmol C m2 d1, pCO2 =20atm). Areas of enhanced NCP were correlated with shallow mixed layer depths, suggesting that production is controlled in part by light limitation. We found good agreement between estimates of NCP based on O2/Ar measurements and those derived from seasonal (mixed layer) inorganic carbon deficits. In ice covered areas, and in areas where surface temperature changes act on shorter timescales than the equilibration of oxygen in the mixed layer, we find that physical controls on surface O2 are of equal magnitude to biological controls, which has important implications for the use of oxygen sensors on autonomous platforms to infer NCP.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/2010EI306.1", "year": 2010, "title": "Storminess and Environmental Changes in the Mediterranean Central Area", "abstract": "Earth ecosystems are not static, and they respond to environmental changes, particularly climatic and anthropogenic. Precipitation varying in its extremeness, with shifts to greater or lesser intensity of individual storms and/or to change in the length and frequency of wet and dry periods, can adversely affect both urban and rural ecosystems. Here, the authors review longterm precipitation records of the central Mediterranean area and employ a Web geographical information system (GIS)-based analytical approach to compare current rainfall impact with historical data on different spatial and temporal scales. Autumn (SeptemberNovember) was recognized as the most hazardous season that marks the evidence of a changing climate, with a shift toward more intense rainfalls in recent times. In the first decade of the third millennium, areas of peninsular and insular Italy have been especially affected by extreme rains. A focus was put on the island of Sicily, where extraordinary rain events occurred in September 2009, discussed in the context of upcoming trends and climate histories. An improved knowledge and understanding of the scale at which changes on extremes occur is essential for dealing with the forthcoming challenges regarding soil and water conservation practices. The characteristics of changes in natural rainfall, its role on terrestrial ecosystems, and its effect on surface water erosion dynamics are discussed. It is argued that understanding these issues are major priorities for future research to promote a better understanding of the Earth interaction with water resources and related hydrological issues.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "", "year": 2015, "title": "Solubility of Atmospheric Nutrients over the Eastern Mediterranean: Comparison between Pure-Water and Sea-Water, Implications Regarding Marine Production", "abstract": "Aerosol filter samples were selected from sample library of Erdemli site; located on the coastline of the Eastern Mediterranean, in order to carry out solubility experiments. The nutrient (PO43-, Sidiss, NO3- and NH4+) solubilities were investigated by using pure-water and sea-water. The arithmetic means of phosphate and dissolved silica indicated distinct difference (larger than 50 %) between pure-water and sea-water whereas; the calculated mean concentrations of nitrate and ammonium did not reveal substantial discrepancy for pure-water and sea-water extractions. The difference for phosphate and silicate might be attributed to pH and ionic strength of sea water, size distribution and association of phosphate/silicate particles with less soluble compounds such as calcium phosphate, kaolinite, opal, quartz and origin of the aerosol species. The difference between pure-water and sea-water extractions for nitrate and ammonium was estimated to be small, corresponding to 1 % to -3 %. This similarity can be ascribed to highly soluble chemical forms such as NH4NO3, Ca(NO3)2, NaNO3 (NH4)2SO4 and NH4HSO4. Calculations revealed that atmospheric P flux would sustain 0.4 % and 0.9 % of the primary production reported for coastal and offshore waters of Cilician Basin. Whereas, atmospheric nitrogen contribution on primary production would be as high as 3.7 % and 8.4 % in coastal and offshore waters, correspondingly. The impact of atmospheric input on the marine productivity became more important particularly during the stratified periods such as summer and autumn. During these period, atmospheric P input might sustain 80 % of the new production whereas, atmospheric N input might support 8 times higher new product than that detected for surface waters.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 17, "name": "Validation" }, { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 14, "name": "Public Health" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 15, "name": "Severe Storms" }, { "id": 19, "name": "Water Quality" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 0, "name": "Agriculture" }, { "id": 10, "name": "Greenhouse Gases" }, { "id": 9, "name": "Floods" }, { "id": 18, "name": "Volcanic Eruptions" }, { "id": 4, "name": "Droughts" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JMARSYS.2014.10.002", "year": 2015, "title": "Seasonal dynamics in diatom and particulate export fluxes to the deep sea in the Australian sector of the southern Antarctic Zone", "abstract": "Particle fluxes were recorded over a one-year period (2001-02) in the southern Antarctic Zone in the Australian Sector of the Southern Ocean. Here, we present the results on the seasonal and vertical variability of biogenic particle and diatom valve fluxes. Total mass and diatom fluxes were highly seasonal, with maxima registered during the austral summer and minima during winter. Biogenic opal dominated sedimentation, followed by carbonate, and very low levels of organic carbon (annual average 1.4%). The strong correlation between opal and organic carbon at both depth levels suggests that a significant fraction of organic matter exported to the deep sea was associated with diatom sedimentation events. Seasonal diatom fluxes appear driven principally by changes in the flux of Fragilariopsis kerguelensis. The occurrence of the sea-ice affiliated diatoms Fragilariopsis cylindrus and Fragilariopsis curta in both sediment traps is considered to correspond to the sedimentation of a diatom bloom advected from an area under the influence of sea ice. Highest fluxes of the subsurface-dwelling species Thalassiothrix antarctica registered at the end of the summer bloom were linked to a drop of the light levels during the summer-autumn transition. This study provides the first annual observation on seasonal succession of diatom species in the Australian sector of the Antarctic Zone, and corresponds, in terms of magnitude and seasonality of diatom fluxes, to those in neighbouring sectors (Pacific and eastern Atlantic).", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5094/APR.2015.016", "year": 2015, "title": "Radiative implication of a haze event over Eastern India", "abstract": "Aerosol haze degrades visibility by the process of absorption and scattering of aerosols. In the present study an attempt has been made to characterize the physical and optical properties of aerosols during a haze event on 29 March 2012 and assess its implication on radiative forcing. In this context representative clear (2 March 2012) and normal (19 March 2012) days were identified in terms of their Aerosol Optical Depth (AOD) loading over Hyderabad. On the hazy day, a huge spread of haze was observed over the eastern part of India by MODerate resolution Imaging Spectroradiometer (MODIS) on board Terra satellite which is represented by high Aerosol Optical Depth at 550 nm. In-situ observations on hazy day showed an enhancement of columnar AOD500 respectively by 4.5 and 1.8 fold in comparison to clear and normal days. Significant increase in the scattering coefficient and a moderate enhancement of Single Scattering Albedo (SSA) are observed on hazy day compared to normal day. Study also showed that Diffuse-to-Direct- beam irradiance Ratio (DDR) had increased 4.5 times at 496.6 nm spectral band on hazy day. LIDAR (LIght Detection And Ranging) observations on hazy night showed a threefold increase in aerosol backscattering below the Atmospheric Boundary Layer (ABL) compared to normal representative night. The hazy day is characterized by large negative surface forcing (87.82 W m2) when compared to normal day (53.90 W m2). A large positive enhancement of atmospheric forcing of 30.56 W m2 is observed on hazy day compared to normal day.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ENVSOFT.2023.105711", "year": 2023, "title": "pRecipe: A global precipitation climatology toolbox and database", "abstract": "Remote sensing data and model simulations of precipitation complemented the traditional surface measurements and offer unprecedented coverage on a global scale. However, the substantial heterogeneity among data products has hindered this unique opportunity to obtain a robust quantification of the climatologic properties of precipitation globally. Herein we present pRecipe, a package developed in R with reproducible science as our standard. pRecipe provides functions to download, explore, process, and visualize a database of 24 precipitation data sets at monthly time step and 0.25\n resolution (20CR v3, CHIRPS v2.0, CMAP, CMORPH, CPC-Global, CRU TS v4.06, EM-EARTH, ERA-20C, ERA5, GHCN v2, GLDAS-CLSM, GLDAS-NOAH, GLDAS-VIC, GPCC v2020, GPCP v2.3, GPM IMERGM v06, MSWEP v2.8, NCEP/DOE R2, NCEP/NCAR R1, PERSIANN-CDR, PREC/L, TerraClimate, TRMM 3B43 v7, UDel v5.01).", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JMARSYS.2014.10.018", "year": 2015, "title": "Phytoplankton size structure in the southern Bay of Bengal modified by the Summer Monsoon Current and associated eddies: Implications on the vertical biogenic flux", "abstract": "The present study combines field and satellite observations to investigate how hydrographical transformations influence phytoplankton size structure in the southern Bay of Bengal during the peak Southwest Monsoon/Summer Monsoon (JulyAugust). The intrusion of the Summer Monsoon Current (SMC) into the Bay of Bengal and associated changes in sea surface chemistry, traceable eastward up to 90E along 8N, seems to influence biology of the region significantly. Both in situ and satellite (MODIS) data revealed low surface chlorophyll except in the area influenced by the SMC. During the study period, two well-developed cyclonic eddies (north) and an anti-cyclonic eddy (south), closely linked to the main eastward flow of the SMC, were sampled. Considering the capping effect of the low-saline surface water that is characteristic of the Bay of Bengal, the impact of the cyclonic eddy, estimated in terms of enhanced nutrients and chlorophyll, was mostly restricted to the subsurface waters (below 20 m depth). Conversely, the anti-cyclonic eddy aided by the SMC was characterized by considerably higher nutrient concentration and chlorophyll in the upper water column (upper 60 m), which was contrary to the general characteristic of such eddies. Albeit smaller phytoplankton predominated the southern Bay of Bengal (6095% of the total chlorophyll), the contribution of large phytoplankton was double in the regions influenced by the SMC and associated eddies. Multivariate analysis revealed the extent to which SMC-associated eddies spatially influence phytoplankton community structure. The study presents the first direct quantification of the size structure of phytoplankton from the southern Bay of Bengal and demonstrates that the SMC-associated hydrographical ramifications significantly increase the phytoplankton biomass contributed by larger phytoplankton and thereby influence the vertical opal and organic carbon flux in the region.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ENVRES.2023.115907", "year": 2023, "title": "Peculiar weather patterns effects on air pollution and COVID-19 spread in Tokyo metropolis", "abstract": "As a pandemic hotspot in Japan, between March 1, 2020October 1, 2022, Tokyo metropolis experienced seven COVID-19 waves. Motivated by the high rate of COVID-19incidence and mortality during the seventh wave, and environmental/health challenges we conducted a time-series analysis to investigate the long-term interaction of air quality and climate variability with viral pandemic in Tokyo. Through daily time series geospatial and observational air pollution/climate data, and COVID-19 incidence and death cases, this study compared the environmental conditions during COVID-19 multiwaves. In spite of five State of Emergency (SOEs) restrictions associated with COVID-19 pandemic, during (20202022) period air quality recorded low improvements relative to (20152019) average annual values, namely: Aerosol Optical Depth increased by 9.13% in 2020 year, and declined by 6.64% in 2021, and 12.03% in 2022; particulate matter PM2.5 and PM10 decreased during 2020, 2021, and 2022 years by 10.22%, 62.26%, 0.39%, and respectively by 4.42%, 3.95%, 5.76%. For (20212022) period the average ratio of PM2.5/PM10 was (0.319 0.1640), showing a higher contribution to aerosol loading of traffic-related coarse particles in comparison with fine particles. The highest rates of the daily recorded COVID-19 incidence and death cases in Tokyo during the seventh COVID-19 wave (1 July 20221 October 2022) may be attributed to accumulation near the ground of high levels of air pollutants and viral pathogens due to: 1) peculiar persistent atmospheric anticyclonic circulation with strong positive anomalies of geopotential height at 500 hPa; 2) lower levels of Planetary Boundary Layer (PBL) heights; 3) high daily maximum air temperature and land surface temperature due to the prolonged heat waves (HWs) in summer 2022; 4) no imposed restrictions. Such findings can guide public decision-makers to design proper strategies to curb pandemics under persistent stable anticyclonic weather conditions and summer HWs in large metropolitan areas.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ATMOSENV.2023.119966", "year": 2023, "title": "Multi-year total ozone column variability at three Norwegian sites and the influence of Northern Hemisphere Climatic indices", "abstract": "Total ozone column (TOC) measurements are retrieved from the Ozone Monitoring Instrument (OMI) onboard the NASA Earth Observing System (EOS) Aura satellite at the three Norwegian sites: Oslo (59.9N 10.7E, 1 m a.s. l.), Trondheim (63.4N 10.4E, 3 m a.s.l.) and Andya (69.1N 15.7E, 32 m a.s.l.). TOC data have been analysed from 2005 to 2021, in order to detect annual and multi-years total ozone variability. The relationship between geopotential height (GPH) at 250 hPa and total ozone column has been evaluated after showing that monthly anomalies in GPH and TOC are correlated amongst the three sites. The influence of the three Northern Hemisphere Tele Connection (TC) indices (North Atlantic Oscillation, Arctic Oscillation and Scandinavia) on TOC variability has been investigated. It is found that Scandinavia index plays a prominent role for the northernmost latitudes of Andya and Trondheim while North Atlantic Oscillation and Arctic Oscillation indices are weakly correlated (negatively) to TOC and (positively) to GPH at Oslo. The response of TOC variability to the solar activity at the three sites is also explored and it is noticed that in the period of increasing variation of solar activity, significant TOC anomaly events are only observed in Andya and Trondheim.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.5194/HESSD-7-103-2010", "year": 2010, "title": "Monitoring temporary ponds dynamics in arid areas with remote sensing and spatial modelling.", "abstract": "A hydrologic pond model was developed that simulates daily spatial and temporal variations (area, volume and height) of temporary ponds around Barkedji, a village located in the Ferlo Region in Senegal. The model was tested with rainfall input data from a meteorological station and from Tropical Rainfall Measuring Mission (TRMM) satellites. During calibration phase, we used climatic, hydrologic and topographic field data of Barkedji pond collected daily during the 2002 rainy season. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Digital Elevation Model (DEM) and a QuickBird satellite image acquired in August 2005 (2.5 m pixel size) were used to apply the hydrologic model to all ponds (98 ponds) of the study area. With input rainfall data from the meteorological station, simulated water heights values for years 2001 and 2002 were significantly correlated with observed water heights for Furdu, Mous 2 and Mous 3 ponds, respectively with 0.81, 0.67 and 0.88 Nash coefficients. With rainfall data from TRMM satellite as model input, correlations were lower, particularly for year 2001. For year 2002, the results were acceptable with 0.61, 0.65 and 15 0.57 Nash coefficients for Barkedji, Furdu and Mous 3 ponds, respectively. To assess the accuracy of our model for simulating water areas, we used a pond map derived from Quickbird imagery (August 2007). The validation showed that modelled water areas were significantly correlated with observed pond surfaces (r2=0.90). Overall, our results demonstrate the possibility of using a simple hydrologic model with remote sensing data (Quickbird, ASTER DEM, TRMM) to assess pond water heights and water areas of a homogeneous arid area.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/978-90-481-3812-8_4", "year": 2010, "title": "Model assessment and verification", "abstract": "Clustering of observed winds and classification of simulated winds were used for meteorological and air quality model evaluation. We simulated meteorology with MM5 and particulate matter (PM) with CMAQ for December to January 20002001 in the San Francisco Bay Area (SFBA). EOFs were used to classify simulated winds among the patterns identified by a previous clustering of observations. We investigated the match between the classification of the simulated winds and the original clustering. Agreement between the clustering of observed winds and the classification of simulated winds implies model validity. Disagreement serves as a diagnostic tool, indicating how inaccurately modeled winds may explain degraded air quality model performance. This novel framework complements traditional model validation methods.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S11600-023-01143-Z", "year": 2023, "title": "Long-term spatio-temporal trends in atmospheric aerosols and trace gases over Pakistan using remote sensing", "abstract": "One of today's most important environmental problems is air pollution augmentation. Air pollution is getting worse over time and hurts human health. For the current study, various polar orbiting satellites were utilized to collect data on PM2.5, SO2, AOD, CO, and ozone over Pakistan between January 2005 and December 2021. According to the spatial distribution results, these characteristics have high values throughout central Punjab, western Baluchistan, central Sindh, and Khyber Pakhtunkhwa. The seasonal variation in PM2.5, SO2, AOD, CO, and ozone was calculated using monthly data. The greatest value for PM2.5 is 8.7 108 kg/m3 during the monsoon season, while the highest value for SO2 is 1.4 105 kg/m2 during the winter. Over Punjab, Sindh, Baluchistan, KPK, and Gilgit, AOD was between 0.7 and > 1.0, CO was 127.2 ppb, and ozone was 330.7 DU. Furthermore, we create correlation maps of AOD, CO, SO2, PM2.5, and ozone and evaluate their relationship of high and low values across Pakistan. We looked into the 0.99 correlation between AOD and PM2.5, the strongest ever recorded. Despite this, we look at time series graphs to show the rising and falling pattern of these parameters from January 2005 to December 2021. We also used tables to determine the relative change in Multan, Lahore, Karachi, Peshawar, Quetta, Rawalpindi, Faisalabad, Hyderabad, Gujranwala, and Abbottabad in Pakistan from January 2005 to December 2021.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.DYNATMOCE.2023.101386", "year": 2023, "title": "Investigating the unprecedented summer 2022 penetration of the Indian monsoon to Iran and evaluation of global and regional model forecasts", "abstract": "The Indian Summer Monsoon (ISM) significantly impacts the climate of the Asian continent. During the summer of 2022, the penetration of monsoonal waves towards higher latitudes led to severe and unprecedented floods in various parts of Iran, Pakistan, and southern Afghanistan. In this study, we utilized meteorological data from weather stations, satellite remote sensing, reanalysis data, and teleconnection indices to investigate the penetration of monsoonal waves at higher latitudes in Iran. We also employed outputs from two global models, the Global Forecast System (GFS) and Climate Forecast System (CFS), and the Weather Research and Forecasting Model (WRF) regional model, to examine their forecasts of heavy monsoon rains. Our analysis of teleconnection indices revealed that La Ni na, combined with a negative or neutral Dipole Mode Index (DMI) and a positive Indian Monsoon Index (IMI), intensified monsoon-related rainfall in the region. The low-pressure system over India weakened, while the system over central Iran strengthened. Additionally, we observed a meridional rotation of the Somali low-level jet. Generally, southern to southwestern Iran, as well as central and eastern regions, receive moisture from the Arabian Sea due to southerly and easterly winds from water surfaces. Comparing forecasts with 27 days lead times and extended 1015 days from the CFS and GFS global models demonstrated that neither of models accurately predicted the observed range of rainfall over Iran in the extended period. However, the WRF regional model predictions were significantly better. We also discovered that the 48-hour forecast from the WRF model outperformed other forecasts for this case study.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SCITOTENV.2014.11.006", "year": 2015, "title": "Impact of urbanization and land-use/land-cover change on diurnal temperature range: A case study of tropical urban airshed of India using remote sensing data", "abstract": "Diurnal temperature range (DTR) is an important climate change index. Its knowledge is important to a range of issues and themes in earth sciences central to urban climatology and humanenvironment interactions. The present study investigates the effect of urbanization on the land surface temperature (LST) based DTR. This study presents spatial and temporal variations of satellite based estimates of annually averaged DTR over megacity Delhi, the capital of India, which are shown for a period of 11 years during 20012011 and analyzes this with regard to its land-use/land-cover (LU/LC) changes and population growth. Delhi which witnessed massive urbanization in terms of population growth (decadal growth rate of Delhi during 20012011 was 20.96%) and major transformations in the LU/LC (built-up area crossed more than 53%) are experiencing severity in its micro and macroclimate. There was a consistent increase in the areas experiencing DTR below 11 C which typically resembled the urban class viz. from 26.4% in the year 2001 to 65.3% in the year 2011 and subsequently the DTR of entire Delhi which was 12.48 C in the year 2001 gradually reduced to 10.34 C in the year 2011, exhibiting asignificant decreasing trend. Rapidly urbanizing areas like Rohini, Dwarka, Vasant Kunj, Kaushambi, Khanjhawala Village, IIT, Safdarjung Airport, etc. registered a significant decreasing trend in the DTR. In the background of the converging DTR, which was primarily due to the increase in the minimum temperatures, a grim situation in terms of potentially net increase in the heat-related mortality rate especially for the young children below 15 years of age is envisaged for Delhi. Considering the earlier findings that the level of risk of death remained the highest and longest for Delhi, in comparison to megacities like Sao Paulo and London, the study calls for strong and urgent heat island mitigation measures.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 12, "name": "Heat" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S00704-023-04535-9", "year": 2023, "title": "Impact of land use/land cover (LULC) changes on latent/sensible heat flux and precipitation over Turkiye", "abstract": "Landuse and land cover (LULC) changes have some implications on landatmosphere interactions, surface energy budget, and hydrological cycle. The understanding of LULC changes and their interactions with the environment provide better management of agriculture, forests, and water resources. LULC changes are frequently observed in developing countries such as Turkiye and much research has been conducted in this field. However, few studies investigated the countrywide LULC changes and their interactions with energy fluxes and precipitation. In this paper, LULC changes in Turkiye over the last two decades have been evaluated by utilizing an Enhanced Vegetation Index (EVI) derived from the Terra satellite. The latent and sensible heat fluxes were obtained from the Modern-Era Retrospective analysis for Research and Applications (MERRA-2) reanalysis datasets. Precipitation data were acquired from the Tropical Rainfall Measuring Mission (TRMM) satellite. The results showed that EVI has an increasing trend over Turkiye between 2000 and 2021, while climate changeinduced desertification, droughts, and forest fires have threatened the vegetative cover in some portions of the country. The latent heat flux has a rising trend due to increasing vegetative cover and irrigated areas. A slight reduction was observed in sensible heat flux, while a sharp increase was witnessed in specific humidity. EVI represented a high positive correlation (R = 0.84) with sensible heat flux and a moderate positive correlation (R = 0.69) with latent heat flux. No significant relation was determined between EVI and precipitation on a monthly basis.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ATMOSENV.2012.12.036", "year": 2013, "title": "Impact of elevated aerosol layer on the cloud macrophysical properties prior to monsoon onset", "abstract": "Atmospheric aerosols alter the radiation balance by absorption/scattering of solar radiation, and indirectly by modifying the cloud microphysical properties. Observations during the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX) provide a unique opportunity to investigate the aerosolecloud interaction in a dry to wet transition phase prior to the onset of southwest monsoon. It is observed that aerosol loading increased over the central Indian region in spite of the increase in surface rainfall. This aerosol loading was observed mainly in the 2e5 km level above surface. The origin and influence of elevated aerosol layer have been investigated with the help of WRF-Chem simulations by conducting sensitivity experiments for dust emissions, modified based on the satellite observations. To enhance the dust emissions, the erodible fraction over the Thar Desert region is enhanced to an average factor of 1.7 based on TOMS aerosol index (AI) and USGS land use category, which contributed to enhanced dust emissions by a factor of 1.25 over the study region. This enhancement of dust emission from Thar Desert can result in an increased radiative heating due to elevated aerosol layers, which leads to an increase in the ice mixing ratio and ice water content in the regions of dry to wet transition. It is shown that even natural dust emissions (without changes in anthropogenic emissions) may also influence the spatial and temporal distribution of cloud and precipitation and the hydrological cycle.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S41324-023-00530-4", "year": 2023, "title": "Impact of COVID-19 on spatio-temporal variation of aerosols and air pollutants concentration over India derived from MODIS, OMI and AIRS", "abstract": "The atmospheric aerosols and air pollutants affect the earth's atmosphere, human health and climate system. Human-induced aerosols and air pollutants are the major causes of the deterioration of air quality. The COVID-19 lockdown restricted the movement of people and vehicles, stopped industrial and agricultural activities and may have impacts on the aerosols in the atmosphere. Spatio-temporal map of MODIS Terra AOD_550 nm, OMI Aura UVAI, Ozone, NO2,SO 2 and AIRS CO during the lockdown illustrates the significant reduction in their concentration. During the lockdown, the North India shows a record reduction of over 20% in Aerosol Optical Depth and Aerosol Index values. A substantial decrease in AOD and AI was also observed in Eastern and Western parts of India. The average AOD value were reduced from 1.36 (20162019) to 1.09 (2020) over India during the lockdown. The satellite-retrieved aerosol variables over India recorded lowest AOD values on 29th March, 2020 (0.2566) and 21st April 2020 (0.2591). Similarly, air pollutants CO, NO2 and SO2 also significantly reduced in India. Despite all variables showing a reduction in concentration, Ozone recorded an increase in value during lockdown primarily over North and North-eastern parts of India. Western India recorded a substantial reduction in SO2 (47%) followed by Central India (31%). As pan India is considered, CO was reduced by 1%, NO2 reduced by 15.29% and SO2 was reduced by 26.82% during the lockdown period. This abrupt reduction in aerosol and air pollutants concentration over India was mainly due to the lockdown of COVID-19.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S12524-023-01692-2", "year": 2023, "title": "Impact of Biomass Burning on Black Carbon and NO2 Over North Eastern Region of India Using Multi-satellite Observations", "abstract": "Large scale biomass burning like forest fires and crop residue burning can significantly impact the physical environment, including land cover, land use, ecology, habitats, and climate change. We investigated the effect of fire counts on surface Black Carbon mass concentration (BCC) and Tropospheric Columnar NO2 (TCN) over the North Eastern Region (NER) of India in the domain: 20 N30 N and 88 E98 E for 15 years from 2006 to 2020 using MODIS, MERRA-2 and OMI data. Significant fire counts are recorded in January, February, March, and April. An average of 65,000 fire counts is recorded in March and April during the 15 years of study over the domain. TCN is high in Mizoram, Manipur, and Nagaland, followed by Assam, Tripura, and Meghalaya in March and April, which varies from 18.79 9 1014 to 29.08 9 1014 cm-2 in March, 10.76 9 101415.81 9 1014 cm-2 in January and February, and 12.67 9 101414.2 9 1014 cm-2 in April. Spatially averaged BC varies from 1.80 to 2.76 lgm-3 in January and February and 1.822.36 lgm-3 in March. BCC is high in Mizoram, Tripura, Manipur, Nagaland, and Brahmaputra valley of Assam than in the rest of the NER.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2023.106746", "year": 2023, "title": "Four decades of aviation visibility at Bhairahawa airport, gateway to Buddha's birthplace Lumbini, Nepal", "abstract": "Over four decades of visibility data at Bhairahawa airport (BWA), a recently upgraded international airport near Lumbini, a UNESCO heritage site in Nepal has been analyzed. In this study, we also investigated one of the important microclimatic behavior of fog i.e., onset and dispersal timings, and its implication on aviation. Temporal variations of poor visibility conditions at BWA are found to be primarily associated with variations in haze and fog. Haze at BWA accounts for the highest percentage (~27%) of time and its annual occurrence is increasing (0.57% yr 1). There is a significant upward trend of hazy days in all seasons, the highest (1.46% day yr 1) being in post-monsoon. The overall seasonal poor visibility, too, has increased significantly in all seasons, with the highest trend in post-monsoon (1.57% yr 1). Similarly, fog frequency in the winter season has also increased noticeably for fog days (1.05% day yr 1), dense fog days (0.51% day yr 1), general fog hours (0.55% hour yr 1) and dense fog hours (0.20% hour yr 1). We found that fog at BWA is usually formed overnight and dissipates before noon. Daytime onset and late dispersion of fog are more common in the peak winter months of December and January. Further, we investigated the relationship between visibility and aerosol optical depth (AOD) and found a moderate negative correlation (r = 0.66, p < 0.001) between them in the monsoon season. However, AOD is found to have a weaker correlation with visibility during winter (r = 0.36) and pre-monsoon (r = 0.23) seasons, when there is a more pronounced influence of meteorological conditions on the occurrence of visibility. We have observed a better correlation (r = 0.74) between fine particulate matter concentration (PM2.5) and visibility. Examining the effect of relative humidity (RH) on AOD (or, PM2.5) and visibility revealed that higher RH tends to lower visibility. Visibility at BWA airport is gradually worsening due to local and regional air pollution emissions and changing meteorological conditions. The degraded visibility at BWA airport will negatively impact flight safety and timeliness. Effective implementation of regionally coordinated air pollution mitigation measures can be a sustainable step towards the improvement of visibility in long run. However, the installation of ground equipment like CAT-II/III Instrument Landing System (ILS) for aircraft take-off and landings, and advanced surface movement guidance and control system (A-SMGCS) are highly advisable to lessen the damage potential to aviation.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/978-3-031-29916-2_26", "year": 2023, "title": "Forest Fire Emissions in Equatorial Asia and Their Recent Delay Anomaly in the Dry Season", "abstract": "In Equatorial Asia, forest fires are a significant contributor to greenhouse gas emissions. This study explains the conditions of forest fire emissions in Equatorial Asia and how they might connect to precipitation in the region. Integrated satellite and model data were used to relate to forest fire emissions. Several methods were applied to understand the spatial and temporal nature of emissions, namely time-series, time-averaged, correlation, and Hovmoller diagram. The results suggested that from 1980 to 2021, the emissions were generated from three regions: east of Sumatra Island, south and east of Borneo Island, and the capital city of Jakarta on Java Island. During this period, several massive emission events occurred in 1982, 1998, 2002, and 2006. South Borneo was the highest emitter for 41 years. Emissions in Sumatra and Borneo were mainly due to forest fires, while those in Jakarta were due to industries and transportation. The two main emitter islands, Borneo and Sumatra, have shown different strengths of correlation with precipitation. It is considered weak in East Sumatra, around 0.2, while South Borneo is stronger at about 0.5. However, from 2009 onward, Borneo had abnormal conditions, where carbon emissions remained low even in high forest fires. This is contrary to the previous decades. Apart from that, carbon emissions were also delayed after the rainy season. Borneos forest fire emissions were due to peat organic matter burning. From 2009 to 2021, there is a possibility that the peat had regained its ability to hold water, so carbon emissions became lower and delayed. This clearly shows that forest fires have been the main contributor to carbon emissions in Equatorial Asia for several decades, and precipitation plays a crucial role in it. The emissions can be reduced when the peat soil regains its capacity as water storage in long-term precipitation periods.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.4215/RM2022.E21023", "year": 2023, "title": "Evaluation of TRMM 3B43v7 Satellite Precipitation in the Pantanal of Mato Grosso do Sul in the Years 1998 to 2019", "abstract": "Remote sensing can assist in the acquisition of scarce surface data. The analyzes for validation of the precipitation product estimated by the TRMM satellite (Tropical Rainfall Measuring Mission) were carried out with the precipitation data observed on the surface during the period from 1998 to 2019. For this purpose, precipitation data from the Pantanal biome meteorological stations were used, located between the 16 and 22S parallels and the 55 and 58W meridians, and compared with the data from the TRMM 3B42 V7 product algorithms. Statistical analysis was performed based on the correlation coefficient, root mean square error (RMSE), and relative bias (BIAS) between the monthly precipitation data observed on the surface and the estimated precipitation data. The results found for product 3B43 V7 indicated that the precipitation estimates were representative when compared to the surface observations. However, when compared for the rainy and dry periods, there was underestimation and overestimation, respectively, of the product. The product 3B42 V7 satisfactorily represents the precipitation that occurs on the surface.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.GCA.2014.12.019", "year": 2015, "title": "Dissolved silicon and its isotopes in the water column of the Bay of Bengal: Internal cycling versus lateral transport", "abstract": "The concentration of dissolved Si and its isotope composition are measured in the Bay of Bengal (BoB) region of the northern Indian Ocean; the isotope data are the first data set from the northern Indian Ocean. The measurements are made in eight depth profiles closely along the 87E transect (GIO1 section of the international GEOTRACES program) and in a few samples from the northern shelf of the bay. Dissolved Si in the water column varies from 0.6 to 152.5 lmol/kg, whereas the d30Si data cover a range +1.2& to +3.6&. The depth profiles of dissolved Si show generally lower values in the surface increasing with depth, whereas the pattern reverses in the case of d30Si. These vertical distribution patterns of Si and d30Si are similar to those reported in other oceanic regions and suggestive of the significant role of biological processes in governing Si biogeochemistry in the upper layers (top 1500 m). In contrast, dissolved Si in near surface waters of the northern shelf and the southernmost station is exceptionally high. These results indicate a continental supply of dissolved Si from the GangaBrahmaputra river system (GB) and submarine groundwater discharge (SGD) to the shelf region, and an intrusion of high salinity waters from the Arabian Sea in the southern bay. The d30Si values of 1.34 0.10& for deep/bottom waters of the BoB (depth >1500 m) are similar to those reported for the deep Southern Ocean and indicate the dominant control of water mass mixing. The dissolved Si concentrations in the bottom waters of the BoB are generally higher than those of the water mass endmembers, which suggest the need for an additional source of Si; in situ particle dissolution and/or benthic release in the central bay seem to be the potential candidate. The annual Si budget in the top 100 m of the BoB seems to suggest that meso-scale eddies frequently occurring during non-monsoon periods can supply at the most 2.6 g Si/m2/year, which is about 33% of the Si requirement to support new production in the bay. The supply of dissolved Si ( 1.3 0.5 1011 mol/year) from the GB river system and SGD has been calculated based on the distributions of dissolved Si concentration and d30Si in the northern shelf waters. A comparison of this supply with the reported Si flux upstream of the estuarine zone indicates about 40% removal of dissolved Si in the GB estuary. The mass balance of Si isotopes in the deep waters indicates that the dissolution of diatoms is the main cause of excess Si in the bay.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11069-023-05859-5", "year": 2023, "title": "Considering flood scaling property in multi-objective calibration of the SWAT model: a case study in Zijinguan watershed, Northern China", "abstract": "Adopting new technologies to calibrate hydrological models to produce good simulations for water resources or flood risk management is one of the important research topics in hydrology field. Incorporating hydrological signatures and concepts in hydrological model calibration becomes prevalent in recent years. A good realistic simulation of hydrological processes within the catchment is more significant than only achieving good performance at watershed outlet with single-statistical-objective function. This research adopts the concept of flood scaling property, which describes the statistical relationship between flood peak, its contributing areas and additional catchment attributes, to behave as one of the constraints under multi-objective model calibration framework. Several designed calibration scenarios are tested by employing the soil and water assessment tool hydrological model. In comparison with single-objective calibration scenarios, multi-objective calibration method is recommended to obtain both good simulation at catchment outlet and sub-basins reaches. The multi-objective calibration method assists in improving the model performance in terms of flow duration curve and also in reducing the bias of long-term runoff ratio. The proposed model calibration approach reflects the hydrological interaction of flood peaks across sub-basins and takes into account the catchment antecedent wetness and climatic condition for each flood event.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSRES.2014.07.032", "year": 2015, "title": "Comparison of precipitation estimates between Version 7 3-hourly TRMM Multi-Satellite Precipitation Analysis (TMPA) near-real-time and research products", "abstract": "Over the years, blended methods that use multi-satellites and multi-sensors have been developed for estimating global precipitation and resulting products are widely used in applications. An example is the 3-hourly TRMM (Tropical Rainfall Measuring Mission) Multi-Satellite Precipitation Analysis (TMPA) that consists of two products: near-real-time (3B42RT) and research-grade (3B42). The former provides quick, less accurate estimates suitable for monitoring activities; the latter provides more accurate estimates more suitable for research. Both products have been widely used in research and applications. Nonetheless, to improve near-real-time applications, it is important to understand their difference. In this study, seasonal mean difference (MD), mean absolute difference (MAD), root mean square difference (RMSD), and their inter-annual variations in boreal (June, July and August or JJA) and austral (December, January and February or DJF) summers and in different rain regimes over two surface types are investigated on a large scale (50N50S) from 2000 and 2012. Over land, positive MD values (3B42RT N 3B42) dominate, especially in western China, western United States, northwest Asia and over some oceanic regions of light rain in both JJA and DJF. Over ocean, negative MD values (3B42RT b 3B42) prevail, except over regions of light rain. In general, relative (to 3B42) MD values increase with rain rate. Variation of the individual differences between the two products is small (large) over regions of heavy (light) rain. There is no significant inter-annual variation in the seasonal mean statistics. The difference between the two products is likely due to the algorithms and further investigations are needed.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2015.1041621", "year": 2015, "title": "Comparative study of the tropospheric ozone derived from satellite data using different interpolation techniques", "abstract": "Tropospheric ozone (TO) has been derived from the Aura/Ozone Monitoring Instrument (OMI) and the Aura/Microwave Limb Sounder (MLS) over the Indian sub-continent region using a tropospheric ozone residual (TOR) technique. The TO was initially retrieved at a horizontal spatial resolution following that of the Aura/ MLS (300 km), which has a lower horizontal spatial resolution than that of the Aura/ OMI (25 km). To overcome the limitations imposed by data at a lower spatial resolution, we have introduced a 2D rectangular interpolation (RI) algorithm for effective resampling of data to higher horizontal spatial resolutions. The performance of this algorithm has been evaluated by comparison against existing standard techniques such as nearest neighbourhood (NN) and kriging interpolation as well as comparison against in situ ozonesonde observations. Gridded TO estimates were subsequently generated for the region of interest at 25, 50, and 100 km horizontal spatial resolutions for further study.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JQSRT.2014.03.006", "year": 2015, "title": "Black carbon aerosols in urban central China", "abstract": "The first ever (to our knowledge), year-round measurements of Black Carbon (BC) aerosols in Hefei, an urban site of central China, from June 2012 to May 2013 are performed. The aim of this paper is to evaluate the black carbon in Hefei in terms of seasonal, monthly and diurnal variations, including their source identification. The annual mean BC mass concentration MBC is found to be 3.5 7 2.5 gm 3 in Hefei, while the aerosol optical depth shows a yearly average value of 0.6. The seasonality of MBC depicts minimum values in the summer, moderate levels in the spring and fall, and maximum in the winter. The monthly average values of MBC vary threefold, ranging from the lowest average value of 2.0 7 1.0 gm 3 in July to the highest 6.0 7 2.6 gm 3 during January. Diurnal variations exhibit two BC peaks, corresponding to the morning and evening rush hours. Higher median BC concentrations are observed during haze episodes compared with non-haze periods, although low MBC is sometimes observed for high visibility, which is probably indicative of the aerosol scattering dominating diminished visibility. Based on trajectory analyses, the haze BC pollutions are mostly classified into three types from local areas, long-range transport from the Yangtze Delta, and transport from the North China Plain. The median MBC values for haze groups attributed to biomass burning from MODIS wildfire maps are higher than related groups that are not, which is indicative of the significant enhancement of BC aerosols due to agricultural biomass burning. The study suggests that aerosol absorption contributes more to the observed haze episodes in fall compared to other seasons.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.OCECOAMAN.2023.106716", "year": 2023, "title": "Assessment of long-term trends in chlorophyll-a and sea surface temperature in the Arabian Sea and their association with aerosols using remote sensing", "abstract": "Aerosols over the oceanic region significantly influence Earths energy budget and climate change. Therefore, this study examines the spatiotemporal patterns of MODIS retrieved aerosol optical depth, sea surface temperature, Chlorophyll-a, Sea-WiFS retrieved aerosol optical depth, and MERRA-2 model dust mass concentrations over the Arabian Sea (4o N26o N to 50o E 78o E) during the period 20022020. The effects of dust aerosols on phytoplankton blooms using the Mann-Kendall and Theil Sen-slope are also analyzed in this study. An increase in aerosol optical depth (AOD) was observed within the latitudes of (4o N26o N). The AOD shows an increasing trend at 13.4% per year over the Arabian Sea (AS). The highest value of Chl-a (~7 mgm 3) was observed along the coast of Pakistan, Iran, and Oman. Moreover, a negative correlation is found between AOD and sea surface temperature (SST) along the coast of Oman and Somalia, while a strong positive correlation (~0.99) is observed between AOD and Chlorophyll-a (Chl-a) along the coasts of Oman and Somalia.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.52460/SRC.2022.008", "year": 2022, "title": "Application of the WASP Model for Assessment of Aeration Impact on Water Quality of Porsuk River, Turkey", "abstract": "Porsuk Stream is the longest branch of the Sakarya Basin which originates from Murat Mountain and bypasses the provinces of Kutahya and Eskisehir. Based on recent increasing pollution concentrations reported in the literature, the main river is experiencing problems with decreased water quality. In this study, hydrodynamics and water quality parameters are simulated in the Porsuk River via the application of the Water Quality Analysis Simulation Program (WASP) using the available flow and meteorological data. After the validation of the hydrodynamics along the main river, water quality parameters are simulated using the eutrophication module. Simulation of dissolved oxygen concentrations pointed out hypoxia, especially at two locations; Kutahya-Reservoir1 and Alpu-Guroluk segments where dissolved oxygen values stayed well below the standard limits throughout the year. As a mitigation option, aeration applications at these two stations are proposed and the effects of aeration on the simulated parameters of dissolved oxygen, phosphorus and nitrate concentrations are investigated. Aeration at two segments has significantly improved the dissolved oxygen concentrations (from ~3 mg/l to >14 mg/l) whereas it has a more subtle effect on nitrate and phosphorus concentrations.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/S11869-023-01370-9", "year": 2023, "title": "An analysis of aerosol properties during a dust storm due to the TAUKTAE cyclone using remote sensing", "abstract": "Millions of people suffer from health problems due to poor air quality in regions of high particulate pollution. Therefore, this paper proposes for better understanding of the impact of dust storms on both short- and long-term environmental factors that can help in a preferable formulation of warning and prediction scenarios in arid regions. We evaluate the effect of dust storms on the optical properties of aerosols and meteorological parameters by employing both ground-based and satellite remote sensing approaches. For this, we use AERosol RObotic NETwork (AERONET), MODerate resolution Imaging Spectroradiometer (MODIS), Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), Ozone Monitoring Instrument (OMI), Suomi National Polar-orbiting Partnership (S-NPP), and Sentinel-5 Precursor (S5P) to retrieve aerosol optical properties from 15 May 2021 to 20 May 2021 over Karachi. At 550nm, the instantaneous maximum values of aerosol optical depth (AOD) are measured to be ~0.8, and 0.59 on 16 May 2021, and the lowest values of Angstrom Exponent (AE) are discovered to be ~0.2, and ~0.26 by Aqua-MODIS and AERONET respectively. Such observations are attributed to dust aerosols over Karachi; these values are more than those that might be expected on an ordinary day. We also found S5P and OMI retrieved ultraviolet aerosol index (UVAI) of about 1 and ~1.9 on 17 May 2021 respectively which indicate the presence of absorbing (dust) aerosols. Subtypes of aerosols derived by CALIPSO with vertical profile taken on 17 May 2021 segregate the widespread aerosol burden as contaminated dust particles over surrounding regions of Karachi (24.4830.59 N, 69.0170.56 E).", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.SCITOTENV.2023.164733", "year": 2023, "title": "Aerosols heat up the Himalayan climate", "abstract": "The impact of aerosols, especially the absorbing aerosols, in the Himalayan region is important for climate. We closely examine ground-based high-quality observations of aerosol characteristics including radiative forcing from several locations in the Indo-Gangetic Plain (IGP), the Himalayan foothills and the Tibetan Plateau, relatively poorly studied regions with several sensitive ecosystems of global importance, as well as highly vulnerable large populations. This paper presents a state-of-the-art treatment of the warming that arises from these particles, using a combination of new measurements and modeling techniques. This is a first-time analysis of its kind, including ground-based observations, satellite data, and model simulations, which reveals that the aerosol radiative forcing efficiency (ARFE) in the atmosphere is clearly high over the IGP and the Himalayan foothills (80135 Wm2 per unit aerosol optical depth (AOD)), with values being greater at higher elevations. AOD is >0.30 and single scattering albedo (SSA) is 0.90 throughout the year over this region. The mean ARFE is 24 times higher here than over other polluted sites in South and East Asia, owing to higher AOD and aerosol absorption (i.e., lower SSA). Further, the observed annual mean aerosolinduced atmospheric heating rates (0.50.8 Kelvin/day), which are significantly higher than previously reported values for the region, imply that the aerosols alone could account for >50 % of the total warming (aerosols + greenhouse gases) of the lower atmosphere and surface over this region. We demonstrate that the current state-of-the-art models used in climate assessments significantly underestimate aerosol-induced heating, efficiency and warming over the Hindu Kush Himalaya Tibetan Plateau (HKHTP) region, indicating a need for a more realistic representation of aerosol properties, especially of black carbon and other aerosols. The significant, regionally coherent aerosolinduced warming that we observe in the high altitudes of the region, is a significant factor contributing to increasing air temperature, observed accelerated retreat of the glaciers, and changes in the hydrological cycle and precipitation patterns over this region. Thus, aerosols are heating up the Himalayan climate, and will remain a key factor driving climate change over the region.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSENV.2023.119747", "year": 2023, "title": "Variations in aerosol optical characteristics from SKYNET measurements in Beijing", "abstract": "Atmospheric aerosols have significant impacts on climate and environment, so the study on aerosol optical properties is of great scientific significance for climate change and atmospheric environment. The variations in column-integrated aerosol optical properties over Beijing were investigated from March 2016 to December 2019 based on the SKYNET data products. Higher values of AOD and AE found in summer indicate that it is important to pay more attention to fine particle pollution in summer. By fitting the AOD data of SKYNET with AERONET at same waveband, we found that monthly variations in aerosol optical depth estimated from SKYNET observation were mostly consistent with the AERONET data. Aerosols were divided into several modes according to optical characteristics, which deepen some insight into aerosol optical and radiative properties and revealed that the weak absorption aerosol dominated and contributed much to the radiation transport in Beijing. Data derived from the polarization lidar CALIPSO were combined with aerosol optical depth (AOD) from SKYNET and these results were consistent, which further identified the scientific of data. The random forest algorithm was used to interpolate the missing AOD500nm observations. The original results and the interpolation results were fitted with MODIS respectively, which proved that the random forest algorithm can supplement the missing results well. This work will be of great significance in addressing the impacts of aerosols on climate and environment, and will help reduce the uncertainty of the impacts of aerosols on the Earth's radiation budget. All work will provide scientific support for the prevention and control of specific pollution.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/SU15054209", "year": 2023, "title": "What Is Polluting Delhis Air? A Review from 1990 to 2022", "abstract": "Delhis annual average PM2.5 concentration in 202122 was 100 g/m320 times more than the WHO guideline of 5 g/m3. This is an improvement compared to the limited information available for the pre-CNG-conversion era (~30%), immediately before and after 2010 CWG (~28%), and the mid-2010s (~20%). These changes are a result of continuous technical and economic interventions interlaced with judicial engagement in various sectors. Still, Delhi is ranked the most polluted capital city in the world. Delhis air quality is a major social and political concern in India, often with questions regarding its severity and primary sources, and despite several studies on the topic, there is limited consensus on source contributions. This paper offers insight by reviewing the influence of Delhis urban growth since 1990 on pollution levels and sources and the evolution of technical, institutional, and legal measures to control emissions in the National Capital Region of Delhi.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.MARENVRES.2023.105972", "year": 2023, "title": "Winter phytoplankton size classes in the Northeastern Arabian Sea based on in-situ and remote sensing methods", "abstract": "Phytoplankton size classes (PSCs) are important in marine ecosystems because they organise the food chain and trophic pathways, which determine the overall biological environment. Based on three FORV Sagar Sampada cruises, the current study provides changes in PSCs in the Northeastern Arabian Sea (NEAS; north of 18 N) during different phases of the Northeast Monsoon [NEM (NovemberFebruary)]. During all three phases of NEM such as early (November), peak (December), and late (February), in-situ chlorophyll-a fractionation data revealed that nanoplankton (220 m) predominated, followed by microplankton (>20 m) and picoplankton (0.22.0 m). This was primarily because winter convective mixing in the NEAS maintains only a moderate level of nutrients in the surface mixed layer, which is more conducive to the dominance of nanoplankton. Brewin et al. (2012) and Sahay et al. (2017) have satellite-based PSC estimation algorithms; the former was developed for the entire Indian Ocean, while the latter is a modification of the former for the Noctiluca bloom-infested NEAS, with a claim that such blooms are typical of the NEM. When current in-situ PSCs data were compared to algorithm-based NEM data, Brewin et al. (2012) revealed a more realistic PSCs contribution pattern, especially in oceanic waters, with nanoplankton predominating except during early NEM. But the PSCs data from Sahay et al. (2017) showed a high degree of variation from the in-situ data, demonstrating the dominance of pico- and microplankton and a notably small contribution from the nano phytoplankton. The current study showed that Sahay et al. (2017) is inferior to Brewin et al. (2012) at quantifying PSCs in the NEAS without Noctiluca blooms, and provided evidence to show that Noctiluca blooms are not a typical feature of the region during the NEM.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCIAF.2023.E01914", "year": 2023, "title": "A case study of weather impact on air pollution during the COVID-19 pandemic in South Africa", "abstract": "This study investigates climate, weather characteristics, and air pollution during the third COVID-19 wave in South Africa. During this time, a decrease in of SO2 and NO2 column mass was observed. The investigation displays a positive trend in for tropospheric Ozone (O3) mass mixing in winter over the last two decades with a fitted slope of 1.0005. Despite the negative trend for the daily changes (for all 12 months) of the total column mass density for PM2.5 during the year before the pandemic and two years after for pandemic years, they have slightly increased specifically during winter COVID-19 third wave time. The temporal seasonal yearly time changes (19612021) of different meteorological parameters such as surface temperature, low-level vertical pressure velocity, low-level relative humidity, and precipitation rate over South Africa show sharp changes from 2020 to 2021. This analysis indicates rather colder surface temperatures, smaller but positive low-level vertical velocity, slightly higher low-level relative humidity, and higher total country precipitation rate in the study area during the COVID-19 pandemic years. Weather chart analysis displays a very stable atmospheric condition during the third wave of COVID-19 peak time. This is correlated with the extension of the atmospheric ridge associated with a blocking high pressure, downward motion, positive vorticity, and rather weak winds specific in the north, west, and central areas causing atmospheric stability and possible accumulation of the atmospheric pollution corresponding to the higher COVID-19 cases during the South Africa third wave.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JMARSYS.2023.103934", "year": 2024, "title": "Physical mechanisms affecting phytoplankton variability along the Chilean coast", "abstract": "Chile has high phytoplankton production due to being a classic example of an Eastern Boundary Upwelling System. Monthly averaged chlorophyll- (Chl) and physical parameters (sea surface temperature, precipitation rate, southerly and westerly winds) were studied off the Chilean coast from 2002 to 2018, in order to understand the primary production along this important ocean margin. The coastal margin was split into three zones and ten sub-sections. The Northern Zone had a low phytoplankton production with small seasonal variability, except in its north. This pattern is due to a narrow shelf, weak winds, lack of precipitation and relatively stable weather conditions driven by the Southeast Pacific Subtropical Anticyclone (SPSA). The Central Zone presented a seasonally varying production, with a high Chl concentration in summer and early spring. This is linked to the SPSA movement and sunlight reduction during the winter. A high Chl activity is seen in the Southern Zone despite this Zone being at the limits of the SPSA effect, leading to weak longshore winds only during the warm season. Overall, this study has demonstrated the importance of shelf width and the upwelling driven by the presence or absence of the SPSA for ocean primary production. Thus, the most productive region is from 35S to 45S owing to both variables being present.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.31398/TPJF/29.2.2022-0024", "year": 2022, "title": "First Report on the Reproductive Biology of the Redtail Scad Decapterus kurroides Bleeker, 1855 in Iligan Bay, Southern Philippines", "abstract": "This study provided the first report on the reproductive biology of the redtail scad, Decapterus kurroides. The reproductive activity of the redtail scad was assessed to characterize its sex ratio, spawning period, length at maturity, and fecundity. Meanwhile, remote sensing data on environmental variables were accessed from Giovanni online data system. Fish samples were collected monthly from October 2017 to September 2018 from both commercial and municipal landed catches. Male D. kurroides was found to have a larger size than the female in terms of mean total length and mean body weight, but it did not differ significantly from the female (t = 1.31, df = 1,348, p = 0.19). Collected male and female samples were mostly in the 15.00 18.00 cm size class. Overall sex ratio exhibited female dominance (1.2:1), which significantly deviated from the 1:1 ratio (x2 = 8.17, p = <0.05). As expected for tropical fish, spawning of D. kurroides occurred year-round, with peak spawning in December and minor spawning events in March and August, as reflected in the monthly percent occurrence of different gonad maturity stages and gonadosomatic index evolution. Among the environmental variables evaluated, sea surface temperature appeared to have more influence on the spawning of D. kurroides followed by chlorophyll-a concentration. Females matured at a length of 17.2 cm, while males matured at a length of 17.6 cm. Absolute fecundity ranged from 6,416 to 197,672 eggs per female with a mean of 61,733 3,955 and increased proportionally with gonad weight. Information from this study may be used to formulate effective management strategies for the resource.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/TOXICS11070553", "year": 2023, "title": "Perspective on Particulate Matter: From Biomass Burning to the Health Crisis in Mainland Southeast Asia", "abstract": "Air pollution, notably particulate matter pollution, has become a serious concern in Southeast Asia in recent decades. The combustion of biomass has been recognized to considerably increase air pollution problems from particulate matter in this region. Consequently, its effect on people in this area is significant. This article presents a synthesis of several datasets obtained from satellites, global emissions, global reanalysis, and the global burden of disease (GBD) to highlight the air quality issue and emphasize the health crisis in mainland Southeast Asia. We found that the death rates of people have increased significantly along with the rise of hotspots in mainland Southeast Asia over the last two decades (20002019). In comparison, most countries saw a considerable increase in the predicted fatality rates associated with chronic respiratory illnesses during those two decades. Several reports highlight the continued prevalence of chronic respiratory diseases likely related to poor air quality in Southeast Asia.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 14, "name": "Public Health" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S13762-023-05077-3", "year": 2023, "title": "Elemental ratios as tracers of the sources of mineral dust in north-eastern Sahara", "abstract": "Abstract\n \n The objective of this study is to confirm the possibility of tracing sources of airborne mineral dust using elemental ratios. The region of study is the north-eastern part of the Sahara where dust compositional data were lacking; 272 mineral dust samples collected at 3 experimental stations of Egypt were analyzed by X-ray fluorescence. Based on the mineral dust concentration, 65% of the samples correspond to moderate (310 g m\n 3\n ), 22% to medium (1025 g m\n 3\n ), and 13% to intense (> 25 g m\n 3\n ) dust events. The Ca/Al and (Mg + Ca)/Fe ratios were found to be strongly correlated and their ranges of variation to cover are more than one order of magnitude, which confirms their interest for the tracing of the dust sources. Using a combination of MODIS satellite observations, HYSPLIT back-trajectory analysis, and simulations with dust emission models, the large (> 6) and intermediate (26) Ca/Al ratios were shown to correspond to dust originating from saline playas (chotts) and calcareous surfaces, respectively. Conversely, the lowest (", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S43832-023-00035-Z", "year": 2023, "title": "Detection of spatial and temporal precipitation patterns using remotely sensed data in the Paranapanema River Basin, Brazil from 2000 to 2021", "abstract": "Abstract\n Precipitation is the major input of the hydrological cycle in tropical regions. Changes in the spatial and temporal patterns of precipitation should be investigated in order to provide in-time information for both water and land use planning. Climate and land use changes have been influencing modification in the water cycle, demanding adaptations and increasing the vulnerability of water-dependent systems. This study investigated spatial and temporal changes in precipitation patterns in the Paranapanema River Basin (PPRB), Brazil. The PPRB region is an important agricultural and hydroelectric power generation hub and has been suffering from water crises in recent years, and more intensely in the last 510 years. The analysis used remote sensing precipitations data from September 2000 to August 2021 (summing up twenty-one hydrological years) at 0.1 resolution. Exploratory Spatial and Temporal Data Analysis (ESTDA) were applied to verify spatial local autocorrelation and hot/cold spots clusters, and temporal trends, homogeneity, and change points in the time series at Hydrological Planning Unit (HPU) scale level. The significant results were discussed based on statistical tests and land use cover change data. There is a strong presence of precipitation spatial patterns in the PPRB. Also, the PPRB presented modifications in the precipitation regime over the analyzed period, with significant change points around 20152017. Further monitoring is recommended in order to confirm these results in the long term, however, the provided information can already be used as an award to local and regional water bodies installed in the river basin, supporting informative water management.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/978-981-16-4482-5_8", "year": 2022, "title": "Role of Biomass Burning in Greenhouse Gases Emission", "abstract": "To meet electricity production and transportation, cooking, agricultural-field clearance for crop-rotation, we are consuming fossil fuels through combustion and burning the biomass. When these fuels are burnt, depending on fuel-type, combustion efficiency, and moisture content in the fuel, it releases a lot of aerosols (aka particulate matter), CO2, CH4, SO2, and other gaseous species. With the rise in the global population, the cumulative effect of anthropogenic activities is raising the level of pollutants in the atmosphere and also in the other components of the environment in general. Natural green barriers (forests) intake CO2 and a major source of O2 also do play a crucial role in adsorbing particulate matter, thereby reducing ambient PM levels. Deforestation, owing to unprecedented urbanization, is the other major factor of increasing greenhouse gas levels. Furthermore, industrial emissions from fertilizers, cement production, coal mining activities, and oil extraction generate a huge amount of greenhouse gases and toxic products. Also, landfills occupied with garbage is a potential source of greenhouse gases, viz. CO2 and CH4. Ambient records on rising levels of greenhouse gases and particulate matter in the last couple of decades is an alarming situation and urge for initiatives towards effective interventions to mitigate the air pollution for better planetary health and its sustainability. In this chapter, we have discussed greenhouse gases emissions from biomass burning (BB) focusing mainly on long-term global records in a concise manner. Some of the initiatives to tackle air pollution and recommendations are also provided for future interventions and mitigation policy makers.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3934/ENVIRONSCI.2022017", "year": 2022, "title": "Carbon monoxide and nitrogen dioxide patterns associated with changes in energy use during the COVID-19 pandemic in Kenya", "abstract": "\nEnvironmental degradation, including air quality deterioration, has been mainly attributed to anthropogenic activities. Air pollution has become a pressing issue in industrialised and highly populated areas due to the combustion of fossil fuels and industrial operations. Recently, the COVID-19 pandemic led to a nationwide lockdown to control the spread of the coronavirus. This imposed restrictions on many economic activities, thus providing the environment with an opportunity to heal. The COVID-19 response measures adopted by most countries, including lockdown, restricted movement, and other containment measures, led to a significant decrease in energy use in the transport sector. Due to low electricity access levels in developing countries, traditional energy sources make up the bulk of energy used for most domestic energy services. Biomass combustion emits carbon monoxide (CO), while the transport sector is a major contributor of nitrogen dioxide (NO2). This study was purposed to investigate the short-term effects of COVID-19 on CO and NO2 concentration levels in Nairobi, Vihiga and Tana River counties. The study utilised data on CO surface concentration, NO2 column concentration and reported COVID-19 cases. Time series, correlation analysis and spatial and temporal map analysis were carried out to investigate the changes and relationships among the study parameters. The three counties were selected based on the urbanisation and population. Nairobi county represented an urban setting, while the Vihiga and Tana River counties represented rural areas with high and low population densities, respectively. The CO surface concentrations in Nairobi and Vihiga county significantly correlated with the COVID-19 cases, with both counties portraying negative correlations, i.e., 0.59 (P-value: 0.008) and 0.45 (P-value: 0.05), respectively. NO2 column concentration also exhibited a significant negative relationship with reported COVID-19 cases in the Vihiga (0.018, P-value = 0.05) and Tana River (0.17, P-value = 0.00) counties. These findings highlight the need for demographic and economic considerations in CO and NO2 assessments, and allude to a decreased health risk due to CO and NO2 emissions during the COVID-19 pandemic.\n", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/978-3-030-33424-6_8", "year": 2020, "title": "Long-Term Analysis of Water Quality in Chilika Lagoon and Application of Bio-optical Models for Cyclone Impact Assessment", "abstract": "A comprehensive analysis of sediment and phytoplankton dynamics in Chilika lagoon by synthesizing various remote sensing datasets is presented in this study. The goal of the study was to monitor and analyze the spatio-temporal variability of total suspended sediment (TSS) and chlorophyll-a (chl-a) concentration and associated environmental forcings in the coastal lagoon. NASAs Moderate Resolution Imaging Spectroradiometer (MODIS) surface reflectance cloud free data was used to develop a TSS and chl-a model. Finally, a case study showing implication of satellite based TSS and Chl-a models to assess the impacts of natural hazards such as cyclones on water quality of Chilika Lagoon is presented. This case study is based on comparing the effect of two anniversary very severe cyclonic storms (VSCSs): category-5 Phailin (12 October, 2013) and category-4 Hudhud (12 October, 2014) that impacted the lagoon. Analysis for 14 years (20012014) using MODIS 8-day composites (MOD09Q1) data indicated that the seasonal variability of TSS is dominant in all the three sectors of the lagoon compared to inter-annual variability. The main reason for large variations in the northern sector is the shallow depth and intrusion of large sediment discharge from Mahanadi River from the northern side, which is the largest fresh water distributary for Chilika Lagoon. Anniversary cyclone impact analysis revealed that Phailins impact on Chilika Lagoon and its watershed resulted in unprecedented levels of precipitation and runoff before-during-after the landfall, which shattered the typical sectorial turbidity gradient. Exponential increase in turbidity because of a combination of run-off and wind driven re-suspension of fine sediments resulted in strong attenuation of light in water column post-Phailin. Limited light condition coupled with enhanced flushing rate due to flooded river and increased freshwater discharge reduced the Chl-a concentration after the passage of Phailin. In contrast, relatively farther landfall location, trajectory away from the lagoon, relatively lower wind intensity and short duration of stay of VSCS Hudhud, led to lesser precipitation and surface runoff compared to Phailin. Consequently, lagoon did not experience a drastic increase in turbidity and light attenuation. Sufficient light availability, stable wind, reduced flushing all favored the phytoplankton growth after passage of Hudhud and thus, Chl-a concentration increased almost threefold in all the sectors of the lagoon. The approach used in this study can be applied to other cyclone-prone coastal areas. Coupling of satellite based observation with modelling output from systems such as Giovanni can improve monitoring program implemented in numerous coastal estuaries and lagoons.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1073/PNAS.1524888113", "year": 2016, "title": "Indonesian fire activity and smoke pollution in 2015 show persistent nonlinear sensitivity to El Nino-induced drought", "abstract": "The 2015 fire season and related smoke pollution in Indonesia was more severe than the major 2006 episode, making it the most severe season observed by the NASA Earth Observing System satellites that go back to the early 2000s, namely active fire detections from the Terra and Aqua Moderate Resolution Imaging Spectroradiometers (MODIS), MODIS aerosol optical depth, Terra Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO), Aqua Atmospheric Infrared Sounder (AIRS) CO, Aura Ozone Monitoring Instrument (OMI) aerosol index, and Aura Microwave Limb Sounder (MLS) CO. The MLS CO in the upper troposphere showed a plume of pollution stretching from East Africa to the western Pacific Ocean that persisted for 2 mo. Longer-term records of airport visibility in Sumatra and Kalimantan show that 2015 ranked after 1997 and alongside 1991 and 1994 as among the worst episodes on record. Analysis of yearly dry season rainfall from the Tropical Rainfall Measurement Mission (TRMM) and rain gauges shows that, due to the continued use of fire to clear and prepare land on degraded peat, the Indonesian fire environment continues to have nonlinear sensitivity to dry conditions during prolonged periods with less than 4 mm/d of precipitation, and this sensitivity appears to have increased over Kalimantan. Without significant reforms in land use and the adoption of early warning triggers tied to precipitation forecasts, these intense fire episodes will reoccur during future droughts, usually associated with El Nino events.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 1, "name": "Air Quality" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JGLR.2018.08.014", "year": 2018, "title": "Lake Turkana, major Omo River developments, associated hydrological cycle change and consequent lake physical and ecological change", "abstract": "This study aimed to explore Lake Turkana's ecological reliance on hydrology and to determine the hydrological changes and consequences arising from the major hydropower and irrigation developments in the lake's basin. The major developments on Ethiopia's Omo River are especially significant as this river provides over 80% of the lake's annual freshwater influx and associated nutrients. The cascade of hydropower dams permanently dampens the natural hydrological cycles and lake level variability. The driving force of the flood influx to the lake is curtailed and the pattern of lake currents will adjust. Ultimately 80% of the river inflow to the lake will be regulated. Large volumes of water are required to initially fill the hydropower dam reservoirs. During 201516 when the huge Gibe III reservoir was filled, Lake Turkana's water level declined 2 m. The study has shown that large-scale irrigation schemes in the Lower Omo can potentially abstract 50% of the Omo River water, and that this would cause the lake level to shrink permanently to the detriment of the lake ecology. Possible lake level drops of over 15 m are demonstrated. The basin's natural capital is being replaced by large-scale plantation developments. The hydrological changes are drastic and the ecological consequences on Lake Turkana have not been fully understood. Without serious mitigation measures, Lake Turkana is a potential African Aral Sea disaster in the making, emulating what has happened to other great lakes such as Lake Chad.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/HYDROLOGY8030133", "year": 2021, "title": "Regional Climate Change Impact on Coastal Tourism: A Case Study for the Black Sea Coast of Russia", "abstract": "Regional climate change is one of the key factors that should be taken into account when planning the development of the coastal tourism, including investments and construction of tourism-related infrastructure. A case study for the Black Sea coast of Russia shows a series of potential negative hydrological, meteorological, and biological factors that accompany regional warming of the Black Sea Region, that can impede the development of coastal tourism and devalue billions of dollars in investments by the State, private companies, and individuals. We discuss such natural phenomena as air and sea warming, extreme weather events, coastal upwelling, heavy rains, river plumes, wind and waves, tornado, rip currents, sea-level rise, algal bloom, introduced species, and other features characteristic for the region that seriously impact coastal tourism today, and may intensify in the nearest future. Sporadic occurrence of extreme weather events, unpleasant and sometimes dangerous sea and atmosphere phenomena during the summer tourist season, and from year to year can be of critical psychological importance when choosing your next vacation and tourism destination. The research does not include anthropogenic factors, geopolitical, and socio-economic processes, and the COVID-19 pandemic that play an important role in the sustainable development of coastal tourism as well.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.4209/AAQR.210072", "year": 2021, "title": "Atmospheric Methane Condition over the South Sumatera Peatland during the COVID-19 Pandemic", "abstract": "ABSTRACT Recent anthropogenic activities have degraded peatlands, the largest natural reservoir of soil carbon, thereby reducing their carbon uptake from the atmosphere. As one of the primary sources of methane (CH4) emissions in terrestrial ecosystems, peatlands also contribute to atmospheric greenhouse gases. During the coronavirus disease 2019 (COVID-19) pandemic, Indonesia implemented a lockdown referred to as large-scale social restrictions (LSSR) in areas with high case numbers. To evaluate the effects of anthropogenic activity on peatlands, we investigated the CH4 concentrations in the atmosphere above the tropical peatlands of the Indonesian province South Sumatra before the LSSR (March 2020), during the LSSR (May 2020), and during the corresponding months of the previous year (March and May 2019). Using satellite-retrieved data from NASA, viz., the CH4 concentration and gross primary production (GPP) measured by the Atmospheric Infrared Sounder (AIRS) on board Aqua and Moderate Resolution Imaging Spectroradiometer (MODIS) on board Terra, respectively, we discovered a decrease of approximately 5.5% in the mean CH4 concentration (which averaged 1.73 ppm across the periods prior to lockdown) as well as an increase in the GPP (which ranged from 53.3 to 63.9 g C m2 day1 during the lockdown, indicating high atmospheric carbon intake) during the LSSR. Thus, the restrictions during lockdown, which reduced anthropogenic activities, such as land use conversion and biomass burning, and related events, such as peatland and forest fires, significantly influenced the level of atmospheric CH4 above the peatlands in Indonesia.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.INDIC.2022.100184", "year": 2022, "title": "Air quality estimation using remote sensing and GIS-spatial technologies along Al-Shamal train pathway, Al-Qurayyat City in Saudi Arabia", "abstract": "Air pollution is the atmospheric state in which specific elements concentrations has adverse impacts on human health as well as the environment including global warming, transportation, acidic rain, and ozone layer depletion. Currently, population around the world lives in urban areas coupled with population size in addition to the increasing levels of vehicles which led to deterioration in air quality. Additionally, the clean air is a critical and vital element for environment and health of any region. Therefore, the foci of this research are to detect the air pollution parameters and investigate the relationship with the meteorological parameters including temperature, and wind speed along Al-Shamal train pathway in Al-Qurayyat City in Saudi Arabia using satellite data. This study involved various field visits to distribute questionnaires to residents to gain information about their health status and get their opinions about air quality. The questionnaires analysis manifested poor air quality conditions and thermal pollution due to the rapid urbanization accompanied with the development of the industrial facilities. The main aim of the study was to shed light on using satellite data to detect the concentration of the primary air pollutants including NO2, SO2, and CO to constitute a pre-defensive step to control and improve the air quality in Saudi Arabia. The present study examined using Sentinel-5 Precursor, Moderate Resolution Imaging Spectroradiometer (MODIS), and The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) satellite data to investigate and detect the air pollution parameters in the study area rather than using the traditional measurements from ground stations. The analysis of satellite images revealed an increase in the concentration of air pollution parameters compared to the standard limits of the WHO which can cause crucial negative impacts on the environment as well as human health. Pearson correlation coefficient was used to analyze the relation between various air pollutants with temperature and wind speed with values ranging between 0.0004 and 0.6604. The statistical analysis of air pollutants showed strong linear correlation that may by attributed to the same emission origin. CO and NO2 on roads have a strong correlation and are emitted by vehicles(R (Albugami et al., 2018) = 0.66). NO2 and CO do not seem to have strong correlation with either SO2 or AOD and their correlation coefficients are weaker, that indicating different emissions sources. The AOD in the study area originated mainly from the windblown dust, construction work, and suspension of particles and therefore do not emitted from traffic.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.APR.2023.101674", "year": 2023, "title": "Remote sensing of air pollution due to forest fires and dust storm over Balochistan (Pakistan)", "abstract": "Forest fires and dust storms, inevitable and unprecedented in their intensity and extent, are a major source of atmospheric pollutants. The implementation of both systematic surveillance and lowering air pollution options from forest fires and dust storms remain largely unrecognized in many parts of the world. Therefore, this study examines the air pollution due to forest fires and dust storms over Pakistan using remote sensing techniques. High aerosol optical depth (AOD) (1.5) and ultraviolet aerosol index (UVAI) (4.50) values were observed in central, eastern, and southeastern Pakistan during May 1825 indicating the dominance of absorbing aerosols (i.e., dust, smoke, and mixed-type aerosols). Mixed, dust, smoke, and non-smoke fine-dominated aerosols were observed on May 16 while dust, smoke, and mixed-type aerosols were found on May 23. Contrary to this, dust aerosols were found in abundance over southwestern Pakistan on May 16 and 22, and central and Southern Pakistan on May 23. Moreover, high concentrations of NO2, CO, and HCHO were found in central, eastern, and northeastern Pakistan during forest fire breakouts. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model forward trajectories and concentration weighted trajectory (CWT) analysis also showed that the air masses from northwestern Pakistan carried away atmospheric pollutants from the forest fire region to eastern, northeastern, and southern Pakistan. These findings can be useful for both air quality and forest management in Pakistan.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0010420", "year": 2022, "title": "An unusually long Rift valley fever inter-epizootic period in Zambia: Evidence for enzootic virus circulation and risk for disease outbreak", "abstract": "Rift valley fever (RVF) is a mosquito-borne disease of animals and humans. Although RVF outbreaks are usually reported at 5-15-year intervals in sub-Saharan Africa, Zambia has experienced an unusually long inter-epizootic/-epidemic period of more than three decades. However, serological evidence of RVF virus (RVFV) infection in domestic ruminants during this period underscores the need for comprehensive investigation of the mechanisms of virus perpetuation and disease emergence. Mosquitoes (n = 16,778) captured from eight of the ten provinces of Zambia between April 2014 and May 2019 were pooled (n = 961) and screened for RVFV genome by a pan-phlebo RT-PCR assay. Aedes mosquito pools (n = 85) were further screened by nested RT-PCR assay. Sera from sheep (n = 13), goats (n = 259) and wild ungulates (n = 285) were screened for RVFV antibodies by ELISA while genome detection in pooled sera (n = 276) from domestic (n = 248) and wild ungulates (n = 37) was performed by real-time RT-PCR assay. To examine the association between the long inter-epizootic period and climatic variables, we examined El Nino-Southern Oscillation indices, precipitation anomalies, and normalized difference vegetation index. We then derived RVF risk maps by exploring climatic variables that would favor emergence of primary RVFV vectors. While no RVFV genome could be detected in pooled mosquito and serum samples, seroprevalence was significantly high (OR = 8.13, 95% CI [4.6314.25]) in wild ungulates (33.7%; 96/285) compared to domestic ruminants (5.6%; 16/272). Retrospective analysis of RVF epizootics in Zambia showed a positive correlation between anomalous precipitation (La Nina) and disease emergence. On risk mapping, whilst northern and eastern parts of the country were at high risk, domestic ruminant population density was low (< 21 animals/km2) in these areas compared to low risk areas (>21 animals/km2). Besides evidence of silent circulation of RVFV and the risk of disease emergence in some areas, wildlife may play a role in the maintenance of RVFV in Zambia.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/19475705.2021.1885503", "year": 2021, "title": "Understanding temporary reduction in atmospheric pollution and its impacts on coastal aquatic system during COVID-19 lockdown: a case study of South Asia", "abstract": "The strict lockdown measures not only contributed to curbing the spread of COVID-19 infection, but also improved the environmental conditions worldwide. The main goal of the current study was to investigate the co-benefits of COVID-19 lockdown on the atmosphere and aquatic ecological system under restricted anthropogenic activities in South Asia. The remote sensing data (a) NO2 emissions from the Ozone Monitoring Instrument (OMI), (b) Aerosol Optical Depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS), and (c) chlorophyll (Chl-a) and turbidity data from MODIS-Aqua Level-3 during JanOct (2020) were analyzed to assess the changes in air and water pollution compared to the last five years (20152019). The interactions between the air and water pollution were also investigated using overland runoff and precipitation in 2019 and 2020 at a monthly scale to investigate the anomalous events, which could affect the N loading to coastal regions. The results revealed a considerable drop in the air and water pollution (3040% reduction in NO2 emissions, 45% in AOD, 50% decline in coastal Chl-a concentration, and 29% decline in turbidity) over South Asia. The rate of reduction in NO2 emissions was found the highest for Lahore (32%), New Delhi (31%), Ahmadabad (29%), Karachi (26%), Hyderabad (24%), and Chennai (17%) during the strict lockdown period from AprJun, 2020. A positive correlation between AOD and NO2 emissions (0.230.50) implies that a decrease in AOD is attributed to a reduction in NO2. It was observed that during strict lockdown, the turbidity has decreased by 29%, 11%, 16%, and 17% along the coastal regions of Karachi, Mumbai, Calcutta, and Dhaka, respectively, while a 56% increase in turbidity was seen over the Madras during the same period. The findings stress the importance of reduced N emissions due to halted fossil fuel consumption and their relationships with the reduced air and water pollution. It is concluded that the atmospheric and hydrospheric environment can be improved by implementing smart restrictions on fossil fuel consumption with a minimum effect on socioeconomics in the region. Smart constraints on fossil fuel usage are recommended to control air and water pollution even after the social and economic activities resume business-as-usual scenario.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.3390/ATMOS12010011", "year": 2021, "title": "Observations of Emissions and the Influence of Meteorological Conditions during Wildfires: A Case Study in the USA, Brazil, and Australia during the 2018/19 Period", "abstract": "Wildfires can have rapid and long-term effects on air quality, human health, climate change, and the environment. Smoke from large wildfires can travel long distances and have a harmful effect on human health, the environment, and climate in other areas. More recently, in 20182019 there have been many large fires. This study focused on the wildfires that occurred in the United States of America (USA), Brazil, and Australia using Cloud-Aerosol Lidar with Orthogonal Polarisation (CALIOP) and a TROPOspheric Monitoring Instrument (TROPOMI). Specifically, we analyzed the spatial-temporal distribution of black carbon (BC) and carbon monoxide (CO) and the vertical distribution of smoke. Based on the results, the highest detection of smoke (~14 km) was observed in Brazil; meanwhile, Australia showed the largest BC column burden of ~1.5 mg/m2. The meteorological conditions were similar for all sites during the fires. Moderate temperatures (between 32 and 42 C) and relative humidity (3050%) were observed, which resulted in drier conditions favorable for the burning of fires. However, the number of active fires was different for each site, with Brazil having 13 times more active fires than the USA and five times more than the number of active fires in Australia. However, the high number of active fires did not translate to higher atmospheric constituent emissions. Overall, this work provides a better understanding of wildfire behavior and the role of meteorological conditions in emissions at various sites.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1038/S41467-021-25428-3", "year": 2021, "title": "Fire-derived phosphorus fertilization of African tropical forests", "abstract": "Central African tropical forests face increasing anthropogenic pressures, particularly in the form of deforestation and land-use conversion to agriculture. The long-term effects of this transformation of pristine forests to fallow-based agroecosystems and secondary forests on biogeochemical cycles that drive forest functioning are poorly understood. Here, we show that biomass burning on the African continent results in high phosphorus (P) deposition on an equatorial forest via fire-derived atmospheric emissions. Furthermore, we show that deposition loads increase with forest regrowth age, likely due to increasing canopy complexity, ranging from 0.4 kg P ha1 yr1 on agricultural fields to 3.1 kg P ha1 yr1 on old secondary forests. In forest systems, canopy wash-off of dry P deposition increases with rainfall amount, highlighting how tropical forest canopies act as dynamic reservoirs for enhanced addition of this essential plant nutrient. Overall, the observed P deposition load at the study site is substantial and demonstrates the importance of canopy trapping as a pathway for nutrient input into forest ecosystems.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSRES.2017.03.020", "year": 2017, "title": "Unraveling the spatio-temporal structure of the atmospheric and oceanic intra-seasonal oscillations during the contrasting monsoon seasons", "abstract": "Using remotely sensed data sets of rainfall and outgoing longwave radiation (OLR) over Indian land and adjacent oceanic regions and sea surface temperature (SST) over adjacent oceanic regions; we examine the major characteristics of the intra-seasonal oscillations of Indian summer monsoon (ISM) during the flood and drought years. Intra-seasonal oscillations of rain, OLR and SST corresponding to 3060days transpires to contribute more to the intra-seasonal variability over the Arabian Sea, whereas 1020days' mode is found to be more dominating over the Bay of Bengal during the drought years. Therefore, suggesting that both of the Seas surrounding the Indian land region respond in a different way to the below normal rainfall conditions of Indian land region. Another important finding of the present work is that during the drought years, 3060days intra-seasonal oscillations of SST over both of the seas follow the intra-seasonal oscillations of rain at 3060days' time scale over central India approximately after 26days. Conversely in the flood years, intra-seasonal oscillations of SST at 3060days over the Arabian Sea and Bay of Bengal lead the intra-seasonal oscillations of rain over central India by 6days. Present analysis also reveals that the intra-seasonal variability of ISM at two different time-scales (1020 and 3060days) possess different spatio-temporal characteristics during the contrasting monsoon conditions over the oceanic regions; therefore it is advisable to study the two modes individually for understanding the underlying physical mechanism. Results presented in this paper may be useful for improved ISM prediction.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JASTP.2016.11.001", "year": 2017, "title": "Spatiotemporal assessment of CO2 emissions and its satellite remote sensing over Pakistan and neighboring regions", "abstract": "For the first time, anthropogenic CO2 emissions and spatiotemporal variability of mid-tropospheric CO2 has been discussed using EDGAR database and Atmospheric Infrared Sounder (AIRS) onboard Aqua satellite observations. The EDGAR data indicate an increase of 147% in anthropogenic CO2 emissions from 66,101 to 163,737 Gg for Pakistan during the period of 19902008. Dera Ghazi Khan (Pakistan) is found with the highest increase of 260% of anthropogenic CO2 emissions followed by Delhi (India) 153%, Karachi (Pakistan) 66% and Lahore (Pakistan) 59% whereas a decreasing trend of 53% is observed for Kabul (Afghanistan) during 19902008. Industrial activities, road transportation, open field crop-waste burning, and energy production have been identified as major anthropogenic emission sources of CO2 in the studied region. AIRS CO2 retrievals over Pakistan and adjoining areas of India and Afghanistan show an averaged CO2 to be 3835ppm with a positive trend of 5.05% during December 2002 to February 2012. An elevated value of CO2 has been observed over northern mountainous and high human settlement regions. The seasonal analysis shows a spring maximum 3855ppm with a secondary peak in late autumn, and the highest increasing trend of 5.5% associated with winter. May and August showed maximum and minimum mean monthly values of 3855ppm and 3825ppm respectively. HYSPLIT trajectories of air masses movement have been drawn to track CO2 transport.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-11-10487-2011", "year": 2011, "title": "An important fingerprint of wildfires on the European aerosol load", "abstract": "Abstract. Wildland fires represent the major source of fine aerosols, i.e., atmospheric particles with diameters <1 m. The largest numbers of these fires occur in Africa, Asia and South America, but a not negligible fraction also occurs in Eastern Europe and former USSR countries, particularly in the Russian Federation, Ukraine and Kazakhstan. Besides the impact of large forest fires, recent studies also highlighted the crucial role played by routine agricultural fires in Eastern Europe and Russia on the Arctic atmosphere. An evaluation of the impact of these fires over Europe is currently not available. The assessment of the relative contribution of fires to the European aerosol burden is hampered by the complex mixing of natural and anthropogenic particle types across the continent. In this study we use long term (20022007) satellite-based fires and aerosol data coupled to atmospheric trajectory modelling in the attempt to estimate the wildfires contribution to the European aerosol optical thickness (AOT). Based on this dataset, we provide evidence that fires-related aerosols play a major role in shaping the AOT yearly cycle at the continental scale. In general, the regions most impacted by wildfires emissions and/or transport are Eastern and Central Europe as well as Scandinavia. Conversely, a minor impact is found in Western Europe and in the Western Mediterranean. We estimate that in spring 5 to 35% of the European fine fraction AOT (FFAOT) is attributable to wildland fires. The estimated impact maximizes in April (2035%) in Eastern and Central Europe as well as in Scandinavia and in the Central Mediterranean. An important contribution of wildfires to the FFAOT is also found in summer over most of the continent, particularly in August over Eastern Europe (28%) and the Mediterranean regions, from Turkey (34%) to the Western Mediterranean (25%). Although preliminary, our results suggest that this fires-related, continent-wide haze plays a not negligible role on the European radiation budget, and possibly, on the European air quality, therefore representing a clear target for mitigation.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2010.09.027", "year": 2011, "title": "Effect of urbanization on lightning over four metropolitan cities of India", "abstract": "In the recent years the effect of urbanization on local convections and lightning has been studied very extensively. Here we have analyzed the last 8 years (from 2001 to 2008) data of total lightning, Aerosol Optical Depth (AOD) and rainfall over two inland and two coastal metropolitan cities of India, to study the effect of urbanization on lightning. The lightning and rainfall data are taken from TRMM satellite and AOD data is taken from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra (EOS AM) and Aqua (EOS PM) satellites. Our analysis shows that both the inland cities show considerable enhancement, where as both the coastal cities do not show enhancement in lightning, in the last 8 years. The results show that, over a inland city, where aerosol concentration is not increased appreciably in last few years the enhancement in convective activity and lightning is controlled by thermodynamic effect, where as, where aerosol concentration show increasing trend, aerosols play major roll in enhancement in lightning activity. It has been also found that over a city where aerosol concentration show increasing trend, lightning show a sharp increase due to combined positive effect of thermodynamics and aerosols, however rainfall show only small increase because of negative effect of aerosols on rainfall. The analysis of lightning, aerosols and rainfall over coastal cities do not show any increasing trend in rainfall and lightning activity which suggest that during premonsoon period all these parameters are controlled by large scale processes and therefore heat island effect or aerosol effect are not observed in both the coastal cities.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 12, "name": "Heat" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS12101309", "year": 2021, "title": "Compositional Spatio-Temporal PM2.5 Modelling in Wildfires", "abstract": "Wildfires are natural ecological processes that generate high levels of fine particulate matter (PM2.5) that are dispersed into the atmosphere. PM2.5 could be a potential health problem due to its size. Having adequate numerical models to predict the spatial and temporal distribution of PM2.5 helps to mitigate the impact on human health. The compositional data approach is widely used in the environmental sciences and concentration analyses (parts of a whole). This numerical approach in the modelling process avoids one common statistical problem: the spurious correlation. PM2.5 is a part of the atmospheric composition. In this way, this study developed an hourly spatio-temporal PM2.5 model based on the dynamic linear modelling framework (DLM) with a compositional approach. The results of the model are extended using a GaussianMattern field. The modelling of PM2.5 using a compositional approach presented adequate quality model indices (NSE = 0.82, RMSE = 0.23, and a Pearson correlation coefficient of 0.91); however, the correlation range showed a slightly lower value than the conventional/traditional approach. The proposed method could be used in spatial prediction in places without monitoring stations.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1063/5.0008195", "year": 2020, "title": "Forecasting of extreme flood events using different satellite precipitation products and wavelet-based machine learning methods", "abstract": "An accurate and timely forecast of extreme events can mitigate negative impacts and enhance preparedness. Real-time forecasting of extreme\nflood events with longer lead times is difficult for regions with sparse rain gauges, and in such situations, satellite precipitation could be\na better alternative. Machine learning methods have shown promising results for flood forecasting with minimum variables indicating the\nunderlying nonlinear complex hydrologic system. Integration of machine learning methods in extreme event forecasting motivates us to\ndevelop reliable flood forecasting models that are simple, accurate, and applicable in data scare regions. In this study, we develop a forecasting\nmethod using the satellite precipitation product and wavelet-based machine learning models. We test the proposed approach in the flood-\nprone Vamsadhara river basin, India. The validation results show that the proposed method is promising and has the potential to forecast\nextreme flood events with longer lead times in comparison with the other benchmark models.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.ASR.2015.04.026", "year": 2015, "title": "Carbon monoxide (CO) emissions and its tropospheric variability over Pakistan using satellite-sensed data", "abstract": "This study presents major anthropogenic sources of carbon monoxide (CO) in Pakistan and discusses the spatio-temporal variability of tropospheric CO over Pakistan and neighboring regions of Afghanistan, India and Iran for a period from 2003 to 2012 using satellite-sensed (AIRS/AMSU) data. The results show a large spatio-temporal variability of CO over the study region mostly associated with anthropogenic activities such as crop residue burning, vehicular transport, and electricity and energy generation, and local meteorology. The annual mean value of tropospheric CO is observed to be 1152ppbv that remains almost steady during the study period with decadal increase of only 2%. Due to more anthropogenic emissions of CO and its transport, the eastern zone shows a higher average value of 1222ppbv with 2.7% decadal increase than the western zone (1113ppbv with 1.4% decadal increase). Elevated concentrations of CO have been observed over the Indo-Gangetic Basin, Lahore, Karachi, and Delhi. During the study period large fluctuations in CO mean monthly values are found ranging from 99ppbv to 131ppbv. The fact that, in spite of a large increase in the CO emissions from 2003 to 2012, its average concentration remains almost stable indicates that a large scale regional transport contributes substantially to the tropospheric CO. Carbon monoxide concentrations exhibit a strong seasonal pattern with maximum amplitude in spring and minimum in autumn. July is found to have the highest decadal increasing trend of 13% followed by August at 8%, whereas May has the highest decreasing trend of 8% followed by November at 4.4%.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1029/2022GH000597", "year": 2022, "title": "Impacts of COVID-19 Restrictions on Regional and Local Air Quality Across Selected West African Cities", "abstract": "The emergence of COVID-19 brought with it panic and a sense of urgency causing governments to impose strict restrictions on human activities and vehicular movements. With anthropogenic emissions, especially waste management (domestic and municipal), traffic, and industrial activities, said to be a significant contributor to ambient air pollution, this study assessed the impacts of the imposed restrictions on the concentrations and size distribution of atmospheric aerosols and concentration of gaseous pollutants over West African subregion and seven major COVID-19 epicenters in the subregion. Satellite retrievals and reanalysis data sets were used to study the impact of the restrictions on Aerosol Optical Depth (AOD) and atmospheric concentrations NO2, SO2, CO, and O3. The anomalies were computed for 2020 relative to 20172019 (the reference years). In 2020 relative to the reference years, for area-averaged AOD levels, there was a consequential mean percentage change between 6.7% 21.0% and 19.2% 27.9% in the epicenters and 10.1% 15.4% over the subregion. The levels of NO2 and SO2 also reduced substantially at the epicenters, especially during the periods when the restrictions were highly enforced. However, the atmospheric levels of CO and ozone increased slightly in 2020 compared to the reference years. This study shows that a one cap fits all policy cannot reduced the level of air pollutants and that traffic and industrial processes are not the predominant sources of CO in major cities in the subregion.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JENVMAN.2023.117655", "year": 2023, "title": "Browning of vegetation in efficient carbon sink regions of India during the past two decades is driven by climate change and anthropogenic intrusions", "abstract": "Accurate estimation of carbon cycle is a challenging task owing to the complexity and heterogeneity of ecosystems. Carbon Use Efficiency (CUE) is a metric to define the ability of vegetation to sequester carbon from the atmosphere. It is key to understand the carbon sink and source pathways of ecosystems. Here, we quantify CUE using remote sensing measurements to examine its variability, drivers and underlying mechanisms in India for the period 20002019, by applying the principal component analyses (PCA), multiple linear regression (MLR) and causal discovery. Our analysis shows that the forests in the hilly regions (HR) and northeast (NE), and croplands in the western areas of South India (SI) exhibit high (>0.6) CUE. The northwest (NW), Indo-Gangetic plain (IGP) and some areas in Central India (CI) show low (<0.3) CUE. In general, the water availability as soil moisture (SM) and precipitation (P) promote higher CUE, but higher temperature (T) and air organic carbon content (AOCC) reduce CUE. It is found that SM has the strongest relative influence (33%) on CUE, followed by P. Also, SM has a direct causal link with all drivers and CUE; reiterating its importance in driving vegetation carbon dynamics (VCD) for the cropland dominated India. The long-term analysis reveals that the low CUE regions in NW (moisture induced greening) and IGP (irrigation induced agricultural boom) have an increasing trend in productivity (greening). However, the high CUE regions in NE (deforestation and extreme events) and SI (warming induced moisture stress) exhibit a decreasing trend in productivity (browning), which is a great concern. Our study, therefore, provides new insights on the rate of carbon allocation and the need of proper planning for maintaining balance in the terrestrial carbon cycle. This is particularly important in the context of drafting policy decisions for the mitigation of climate change, food security and sustainability.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ENVC.2023.100699", "year": 2023, "title": "A comprehensive remote sensing-based Agriculture Drought Condition Indicator (CADCI) using machine learning", "abstract": "Agriculture drought is a decrease in soil moisture during a growing season. In this study, a comprehensive remote sensing-based Agriculture Drought Condition Indicator (CADCI) was developed to monitor the agriculture drought in semi-arid environments and assess its effectiveness in rainfed agriculture regions in (A) Jordan and (B) Syria. First, remote sensed-based drought-condition spectral indices [i.e., Vegetation Condition Index (VCI), Temperature Condition Index (TCI), Evapotranspiration Condition Index (ETCI), Precipitation Condition Index (PCI), Soil Moisture Condition Index (SMCI), and Vegetation Health Index (VHI)] were calculated using data from Moderate Resolution Imaging Spectroradiometer satellite (MODIS) [Land Surface Temperature (LST), Normalized Difference Vegetation Index (NDVI), and evapotranspiration (ET)]; the Global Precipitation Measurement (GPMs); the Soil Moisture Active Passive (SMAPs); and Sentinel-1A. Second, Random Forest (RF) was used to estimate and determine the relative importance of these indices based on Standardized Precipitation Index (SPI) values to select the three spectral indices that have the most monthly short-term relative importance in identifying the agriculture drought for semi-arid environments, which were PCI, TCI, and VCI. Third, these indices were integrated to identify the drought severity based on specific thresholds that compare the pixel-specific value with the study area average value. For instance, a severe drought condition is identified if all three indices indicate a drought condition, a moderate drought or mild drought conditions are identified if any two or any one of the indices indicate drought conditions, respectively. Lastly, a none drought condition is identified if none of the indices indicate a drought condition. Finally, the SPI sets for 1 and 3-months (SPI-1 and SPI-3) were used to evaluate the performance of the CADCI. The results showed the CADCI has a high agreement with SPI-1 classes in the study areas, with overall accuracy and Kappa-values of 85% and 0.80, for study area A and 83% and 0.76 for study area B, respectively. Consequently, the CADCI shows its ability to monitor agricultural drought in semi-arid environments. Perhaps, it could be applicable for larger areas due to the spatial resolution of the input dataset.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1007/S11356-023-25613-5", "year": 2023, "title": "Variations in the aerosol index and its relationship with meteorological parameters over Pakistan using remote sensing", "abstract": "Particulate pollution has become a major issue in developing countries including Pakistan. Aerosols are causing severe impacts on climate and human health. To understand the effects of aerosols on the environment and human health, we must first understand their optical and physical properties. In this paper, we used ozone monitoring instrument (OMI) retrieved ultraviolet aerosol index (UVAI) to analyze spatial and temporal distribution, annual and seasonal trends of absorbing aerosols, and their relationship with meteorological parameters (e.g., temperature, relative humidity, and wind speed) over Pakistan from October 2004 to December 2021. Significant spatiotemporal changes in UVAI values were found with high values in southern and central regions and low values in northern regions of Pakistan. The mean UVAI over Pakistan showed an increasing trend of 2.89% year1. Seasonally, UVAI increases at the rate of 3.97% winter1, 3.24% autumn1, 0.81% summer1, and 0.71% spring1. A strong positive correlation of UVAI with precipitation and temperature (~ 0.6) is observed in the central and southern regions of Pakistan. A negative and positive correlation of 0.3223 and 0.4284 of UVAI with CO2 emissions and primary industry is observed in Pakistan, respectively. We also found potential sources of aerosols over major cities of Pakistan using the Hybrid Single Particle Langrangian Integrated Trajectory (HYSPLIT) model. It determines that the dominant aerosols over Karachi are natural aerosols like sea salt and dust particles and anthropogenic aerosols are dominant over Lahore. Moreover, the natural and anthropogenic factors influencing absorbing aerosols are also discussed herein. Considering the outcomes of this study different methods would be used to reduce the concentration of particulate pollution like afforestation, efficient fuel energy consumption, promotion of public transport networks, etc.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S10661-023-11027-W", "year": 2023, "title": "Influence of stubble burning on air quality of Northern India: a case study of Indo-Gangetic plains of India", "abstract": "Stubble burning is an emerging environmental issue in Northern India, which has severe implications for the air quality of the region. Although stubble burning occurs twice during a year, first during AprilMay and again in OctoberNovember due to paddy burning, the effects are severe during OctoberNovember months. This is exacerbated by the role of meteorological parameters and presence of inversion conditions in the atmosphere. The deterioration in the atmospheric quality can be attributed to the emissions from stubble burning which can be perceived from the changes observed in land use land cover (LULC) pattern, fire events, and sources of aerosol and gaseous pollutants. In addition, wind speed and wind direction also play a role in changing the concentration of pollutants and particulate matter over a specified area. The present study has been carried out for the states of Punjab, Haryana, Delhi, and western Uttar Pradesh to study the influence of stubble burning on the aerosol load of this region of Indo-Gangetic Plains (IGP). In this study, the aerosol level, smoke plume characteristics, long-range transport of pollutants, and affected areas during OctoberNovember from year 2016 to 2020 were examined over the Indo-Gangetic Plains (Northern India) region by the satellite observations. By MODIS-FIRMS (Moderate Resolution Imaging Spectroradiometer-Fire Information for Resource Management System) observations, it was revealed that there was an increase in stubble burning events with the highest number of events being observed during the year 2016 and then a decrease in the number of events in subsequent years from 2017 to 2020. MODIS observations revealed a strong AOD gradient from west to east. The prevailing north-westerly winds assist the spread of smoke plumes over Northern India during the peak burning season of October to November. The findings of this study might be used to expand on the atmospheric processes that occur over northern India during the post-monsoon season. The pollutant, smoke plume features, and impacted regions of biomass-burning aerosols in this region are critical for weather and climate research, especially given the rising trend in agricultural burning over the previous two decades.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/RS15102561", "year": 2023, "title": "Geospatial Modeling Based-Multi-Criteria Decision-Making for Flash Flood Susceptibility Zonation in an Arid Area", "abstract": "Identifying areas susceptible to flash flood hazards is essential to mitigating their negative impacts, particularly in arid regions. For example, in southeastern Sinai, the Egyptian government seeks to develop its coastal areas along the Gulf of Aqaba to maximize its national economy while preserving sustainable development standards. The current study aims to map and predict flash flood prone areas utilizing a spatial analytic hierarchy process (AHP) that integrates GIS capabilities, remote sensing datasets, the NASA Giovanni web tool application, and principal component analysis (PCA). Nineteen flash flood triggering parameters were initially considered for developing the susceptibility model by conducting a detailed literature review and using our experiences in the flash food studies. Next, the PCA algorithm was utilized to reduce the subjective nature of the researchers judgments in selecting flash flood triggering factors. By reducing the dimensionality of the data, we eliminated ten explanatory variables, and only nine relatively less correlated factors were retained, which prevented the creation of an ill-structured model. Finally, the AHP method was utilized to determine the relative weights of the nine spatial factors based on their significance in triggering flash floods. The resulting weights were as follows: rainfall (RF = 0.310), slope (S = 0.221), drainage density (DD = 0.158), geology (G = 0.107), height above nearest drainage network (HAND = 0.074), landforms (LF = 0.051), Melton ruggedness number (MRN = 0.035), plan curvature (PnC = 0.022), and stream power index (SPI = 0.022). The current research proved that AHP, among the most dependable methods for multi-criteria decision-making (MCDM), can effectively classify the degree of flash flood risk in ungauged arid areas. The study found that 59.2% of the area assessed was at very low and low risk of a flash flood, 21% was at very high and high risk, and 19.8% was at moderate risk. Using the area under the receiver operating characteristic curve (AUC ROC) as a statistical evaluation metric, the GIS-based AHP model developed demonstrated excellent predictive accuracy, achieving a score of 91.6%.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.APR.2022.101569", "year": 2022, "title": "Assessment of aerosols over five cities of Angola based on MERRA2 reanalysis data", "abstract": "The use of Aerosol Optical Depth (AOD) has been proven as an alternative to the traditional ground-level monitoring of air quality in many countries across the world. Therefore, this study based on MERRA-2 data aims: (i) to characterize the spatiotemporal and component variations of aerosols in the atmosphere over the capital cities (Luanda, Sumbe, Benguela, Huambo and Lubango) of the five most densely populated provinces of Angola from 2010 to 2020; (ii) to analyze the relationship between the monthly mean variation of the total AOD and the meteorological parameters (precipitation, temperature, wind speed, and relative humidity) in those five cities; and (iii) to assess the influence of emissions from the Nyamuragira volcano, located in the Democratic Republic of Congo, on the air quality at the five cities. The most significant contribution to the total AOD was derived from organic carbon, in all the cities, whereby the highest values (0.190.23) were in Luanda. Ranges of sulphates across the coastal cities were higher when compared to the interior cities caused by the emissions inventory data. The value of AOD in all the cities increased and reached the peak during the dry season. The HYSPLIT model showed that air masses from Nyamuragira at various heights in November 2011 reached Luanda and Sumbe, and CALIPSO could confirm the existence of volcanic aerosols in this same period. This study allowed to conclude that the variability of AOD loading depends on seasons and regions, thus providing a little more information about the matter.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.RSASE.2023.100935", "year": 2023, "title": "Remote sensing techniques for monitoring algal blooms in the area between Jeddah and Rabigh on the Red Sea Coast", "abstract": "The Red Sea is known to host and facilitate the growth and reproduction of several species of phytoplankton and algae. The degree of density and distribution of these organisms differ with region. However, very few studies have been conducted on algal blooms in this region. Hence, this study aimed to identify the effectiveness of remote sensing techniques in monitoring and controlling algal blooms in the area extending between the cities of Jeddah and Rabigh on the Red Sea coast. A series of satellite images were used to study algae from January 2020 to March 2021. All study data were subjected to processing and analysis using spectral indices [chlorophyll a (Chl-a); Concentration and Sea Surface Temperature (SST); Normalized Difference Turbidity Index (NDTI); Surface Scum Index (SSI); Surface Algal Bloom Index (SABI); Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI)], and the classification, overlay, and buffer methods. We found that the rate of chlorophyll a (Chl-a) increased in February 2021 and decreased in May 2020, with the algal bloom dwindling with increasing distance from the shores of the Red Sea. Furthermore, despite the varying effectiveness of the spectral indices in estimating the distribution and density of algae in the Red Sea, Landsat SSI was the most effective. One of the primary results of the study was that algal blooms more frequently occur in the winter (February). The study produced a digital map of algal blooms in the study area. Algal blooms exhibited medium inverse correlations with temperature and specific humidity, and strong direct correlation with wind speed. Valley estuaries, close to the beaches, were found to be the most suitable area for the concentration and growth of algae. The study's findings emphasize the need for close monitoring and controlling changes in the components of the marine environment using remote sensing techniques, in order to track the changes that marine plants (algae) are exposed to in the Red Sea.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11356-022-21167-0", "year": 2022, "title": "Urban air quality in Xinjiang and snow chemistry of Urumqi Glacier No. 1 during COVID-19s restrictions", "abstract": "The unprecedented COVID-19 outbreak impacted the world in many aspects. Air pollutants were largely reduced in cities worldwide in 2020. Using samples from two snow pits dug separately in 2019 and 2020 in Urumqi Glacier No. 1 (UG1) in the Xinjiang Uygur Autonomous Region (Xinjiang), China, we measured water-stable isotopes, soluble ions, and black and organic carbon (BC and OC). Both carbon types show no significant variations in the snow-pit profiles dated from 2018 through 2020. The deposition of anthropogenically induced soluble ions (K+, Cl, SO42, and NO3) in the snow decreased to 2040% of their respective concentrations between 2019 and 2020; however, they increased 2- to fourfold from 2018 to 2019. We studied the daily concentrations of SO2 (20192020), NO2 (20152020), CO (20192020), and PM2.5 (20192020) measured in the sixteen major cities and towns across Xinjiang. The variabilities in these air pollutants were supposed to illustrate the air quality in the urban area and represent the change in the source area. The NO2 decreased in response to mobility restrictions imposed by local governments, while SO2, CO, and PM2.5 did not consistently correspond. This difference indicates that the restriction measures primarily affected traffic. The increases in chemical species in the snow from 2018 to 2019 and the subsequent decreases from 2019 to 2020 were consistent with the variations in SO2 and NO2 measured in urban air and estimated by MERRA-2 model. Therefore, the pandemic could possibly have an impact on snow chemistry of the Tien-Shan glaciers via reduced traffic and industrial intensity; more evidence would be obtained from ice cores, tree rings, and other archives in the future.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119111", "year": 2022, "title": "Novel hybrid deep learning model for satellite based PM10 forecasting in the most polluted Australian hotspots", "abstract": "More timely and accurate air quality forecasting could contribute to better public health protection and air pollution prevention. Particulates are a significant indicator for measuring the degree of air pollution. This paper reports on research to model an early warning tool for coarse particulates when assessing the impact of the 12 satellite-derived and ground-based meteorological pollutants out of 30 pollutants considered using hourly Australian data from January 2018December 2020. A one-dimensional convolutional neural network (CNN) was integrated with a one-directional fully gated recurrent unit (GRU) to forecast consecutive hours' air quality. The CNN model acts as a spatial feature extractor, whereas the new generation GRU makes it computationally efficient. The resultant hybrid CNN-GRU is then comprehensively benchmarked outperforming an ensemble of six other deep learning models. The proposed model's efficacy is indicated at the four most air polluted Australian postcodes in the testing phase. A detailed error analysis with visual and statistical metrics for air quality forecasting ascertains the proposed model's countermeasure to reduce harm and loss. The practical tool is immensely beneficial and can be widely deployed to the regions of public health concern where air pollution is a significant hazard.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.GEOMORPH.2020.107590", "year": 2021, "title": "Contrasting climate controls on the hydrology of the mountainous Cauca River and its associated sedimentary basin: Implications for interpreting the sedimentary record", "abstract": "In coupled source-to-sink systems, spatial differences in hydrology and geomorphology influence how processes in the source are recorded in the sink. The catchment of the tropical Cauca River (source) in the northern (Colombian) Andes, and its associated Mojana lowland sedimentary basin (sink), are a model system in which to explore the relationship between climate processes that control runoff and erosion in the upper catchment, and sediment deposition in the lower basin that occurs through avulsion events and seasonal wetland flooding. This study employed historical climate and hydrologic data from the Cauca River watershed and its associated sedimentary basin, along with topographic data and satellite imagery. We discovered that the Cauca River catchment and its associated Mojana Basin are governed by different patterns of intra- and inter-annual climate variability. Biannual passage of the Intertropical Convergence Zone (ITCZ) over the watershed, annual incursion of the Choco Jet, and sub-decadal variability of the El Nino Southern Oscillation (ENSO) all modulate runoff and sediment fluxes that ultimately become fluvial deposits (e.g., crevasse splays, channel and floodplain sediments). Fluctuations in wetland water levels and area, preserved as lacustrine and marsh deposits, are influenced primarily by annual variations in rainfall that are controlled by the yearly northernmost extent of the ITCZ. Long-term erosion in the Cauca River catchment is controlled largely by active tectonism in the northern Central Cordillera. Avulsion events on the Cauca River in 2010 and 2011 occurred as a consequence of levee failure during a period of high runoff associated with the negative phase of the El Nino Southern Oscillation (ENSO) along with higher cross-floodplain than down-valley slopes in the basin.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2020JD033418", "year": 2021, "title": "Understanding Tropical Convection Through Triple Oxygen Isotopes of Precipitation From the Maritime Continent", "abstract": "Monthly precipitation samples from Singapore were collected between 2013 and 2019 for stable isotope analysis to further our understanding of the drivers of tropical precipitation isotopes, in particular, 17O-excess. 18O ranges from 11.34 to 2.34, with a low correlation to rainfall (r = 0.31, p = 0.014), suggesting a weak amount effect. d-excess is relatively consistent and has an average value of 10.89 3.45. Compared to high-latitude regions, 17O-excess in our samples generally falls in a narrower range from 2 to 47 per meg with an average of 21 11 per meg. Moreover, 17O-excess shows strong periodic variability; spectral analysis reveals 3-month, 6-month, and 2.7-year periodicities, likely corresponding to intraseasonal oscillations, monsoons, and the El NinoSouthern Oscillation (ENSO), respectively. In contrast, d-excess shows no clear periodicities. Although spectral analysis only identifies 6-month periodicity in the 18O time series, 18O tracks the Nino3.4 sea surface temperature variability; the average 18O value (5.2) is higher during El Nino years than ENSO neutral years (7.6). Therefore, regional convection associated with monsoons and ENSO has different impacts on 18O, d-excess, and 17O-excess. 17O-excess and d-excess are anticorrelated and do not relate to the relative humidity in moisture source regions. Extremely low humidity and drought conditions in moisture source regions would be required to account for high 17O-excess. Processes during transport and precipitation likely modify these two parameters, especially 17O-excess, which no longer record humidity conditions of moisture source regions. Our findings will be useful for further modeling studies to identify physical processes during convection that alter d-excess and 17O-excess.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.4209/AAQR.220191", "year": 2022, "title": "Trends and Variability of PM2.5 at Different Time Scales over Delhi: Long-term Analysis 2007-2021", "abstract": "ABSTRACT The present study investigated the long-term inter-annual, seasonal, and monthly trend analysis and variability of PM2.5 at different time scales over the national capital, Delhi, India using high-resolution surface observations from six stations during 2007-2021. The non-parametric Mann-Kendall and Theil-Sen slope estimator were used to study the temporal variations. The long-term PM2.5 concentration showed an overall small but statistically significant decreasing trend with an average decrease of -1.35 (95 % CI: -2.3, -0.47) g m-3 year-1. Seasonal trends revealed a significant decreasing value of -3.05 g m-3 year-1 (p < 0.1) for summer, insignificant declining trend of -1.95 g m-3 year-1 for monsoon and no significant trend was found for the post-monsoon and winter season. Except for December and January, all months displayed a decreasing trend for PM2.5 concentration. These findings indicate that particle pollution over the city is declining at a very slow rate. A rising trend was found for relative humidity and surface pressure, whereas a declining trend for wind speed and PBLH noted. No trend was observed for temperature and rainfall. The Pearson linear correlation between PM2.5 and meteorological variables was studied using monthly mean data. Rainfall, air temperature, PBLH, and wind speed showed a negative correlation with PM2.5, whereas surface pressure had a positive correlation and relative humidity displayed an inverted U-shape relationship. The average concentration of PM2.5 in the study period of 15 years remained 125 86 g m-3 (ranging between 20 to 985 g m-3) and during winter, summer, monsoon, and post-monsoon seasons it was 174 75, 101 48, 66 50, and 192 93 g m-3 respectively. The monthly average PM2.5 concentration observed minimum in August and maximum in November. Satellite data of fire events showed that the crop residue burning over the Punjab region had a significant contribution to the peak PM2.5 levels in Delhi during the crop burning period. Government agencies need more strict action plans, especially during winter, to comply with air quality standards.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11869-020-00921-8", "year": 2020, "title": "Impact of COVID -19 pandemic lockdown on distribution of inorganic pollutants in selected cities of Nigeria", "abstract": "The COVID-19 global pandemic has necessitated some drastic measures to curb its spread. Several countries around the world instituted partial or total lockdown as part of the control measures for the pandemic. This presented a unique opportunity to study air pollution under reduced human activities. In this study, we investigated the impact of the lockdown on air pollution in three highly populated and industrious cities in Nigeria. Compared with historical mean values, NO2 levels increased marginally by 0.3% and 12% in Lagos and Kaduna respectively. However, the city of Port Harcourt saw a decrease of 1.1% and 215.5% in NO2 and SO2 levels respectively. Elevated levels of O3 were observed during the period of lockdown. Our result suggests that there are other sources of air pollution apart from transportation and industrial sources. Our findings showed that the COVID-19-induced lockdown was responsible for a decrease in NO2 levels in two of the locations studied. These results presents an opportunity for country wide policies to mitigate the impact of air pollution on the health of citizens.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.AEOLIA.2011.12.001", "year": 2012, "title": "Dust storms and their horizontal dust loading in the Sistan region, Iran", "abstract": "The Sistan region in southeast Iran is considered as one of the most active dust source regions in South west Asia. The strong Levar winds in summer favor the uplift of large quantities of dust from the Hamoun basin, which is located in the northern part of Sistan. After a dry period at the end of the 1999s, and due to land-use change and desiccation of the Hamoun lakes, the frequency and severity of dust storms have been significantly increased. Within this framework, this study analyses the aerosol characteristics, dust loading and air quality over the Sistan region. The dust loading was measured using dust traps up to four and eight meters height (with a one meter distance between the traps) at two locations near the Hamoun basin during the period August 2009 to July 2010. The results show large quantities of transported dust that strongly dependent on the duration of the dust events, and secondarily, on the wind speed and distance from the source region. The grain size distribution of the dusts reveals that the coarser calibers are found at the station nearer to Hamoun, while the large differences in the grain-size distribution found between the two stations indicate significant spatio-temporal variation in dust characteristics. Furthermore, to assess the air quality, Particulate Matter (PM10) concentrations were measured over Zabol city during September 2010 to July 2011, and the Air Quality Index (AQI) was obtained. Daily PM10 levels during intense dust storms rise up to 2000gm3, even reaching to 3094gm3, while the monthly mean PM10 variation shows extreme values (>500gm3) for the period June to October. Analysis of the AQI shows that 61% of the days are associated with a high health risk, while 30.1% are even identified as hazardous.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/IJERPH18073528", "year": 2021, "title": "The Effect of Lockdown Period during the COVID-19 Pandemic on Air Quality in Sydney Region, Australia", "abstract": "In early 2020 from April to early June, the metropolitan area of Sydney as well as the rest of New South Wales (NSW, Australia) experienced a period of lockdown to prevent the spread of COVID-19 virus in the community. The effect of reducing anthropogenic activities including transportation had an impact on the urban environment in terms of air quality which is shown to have improved for a number of pollutants, such as Nitrogen Dioxides (NO2) and Carbon Monoxide (CO), based on monitoring data on the ground and from a satellite. In addition to primary pollutants CO and NOx emitted from mobile sources, PM2.5 (primary and secondary) and secondary Ozone (O3) during the lockdown period will also be analyzed using both statistical methods on air quality data and the modelling method with emission and meteorological data input to an air quality model. By estimating the decrease in traffic volume in the Sydney region, the corresponding decrease in emission input to the Weather Research and ForecastingCommunity Multiscale Air Quality Modelling System (WRF-CMAQ) air quality model is then used to estimate the effect of lockdown on the air quality especially CO, NO2, O3, and PM2.5 in the Greater Metropolitan Region (GMR) of Sydney. The results from both statistical and modelling methods show that NO2, CO, and PM2.5 levels decreased during the lockdown, but O3 instead increased. However, the change in the concentration levels are small considering the large reduction of ~30% in traffic volume.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.JENVMAN.2021.113970", "year": 2022, "title": "Modeling relationship between land surface temperature anomaly and environmental factors using GEE and Giovanni", "abstract": "Land surface temperature (LST) and vegetation cover changes are two indicators of landscapes in a region. The relationship between LST anomalies, elevation, vegetation, and urban growth is significant to conservation. This study addresses this issue using night-time satellite imagery, kernel methods (points aggregation), and the trend analysis for a long-term period (20012017) in Iran. Variables for two seasons (summer and winter) in urban and natural land uses were derived using the Google Earth Engine (GEE) and NASA's Giovanni. Point data derived from raster maps were quantified using statistical kernel and trend analysis. As result, it was observed that LST rise in various elevations, seasons, and land uses. The LST was analyzed through kernels (point aggregation in scatter graphs), which shifted to the right. The LST anomaly in the daytime had the highest maximum value (>4 C) and lowest minimum value (", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.117766", "year": 2020, "title": "Characterizing a landmark biomass-burning event and its implication for aging processes during long-range transport", "abstract": "Springtime biomass burning (BB) in peninsular Southeast Asia (PSEA) has a large impact on the downwind air quality as has been frequently observed at the Lulin Atmospheric Background Station (LABS). Numerous PSEA BB long-range transport events have been observed at LABS in the past decade, of which the biggest event (based on the carbon monoxide (CO) mixing ratio and particulate matter (PM) loading) occurred on March 18, 2009. In this study, for the first time, in-situ observations from LABS, MERRA-2 reanalysis data, and satellite data were combined to elucidate this remarkable event. This event lasted over 29 h and seriously impacted the air quality at LABS. Average concentrations (S.D.) of CO, ozone (O3), and PM10 were 586.2 164.5 ppb, 105.2 23.4 ppb, and 90.4 24.4 g m3, respectively, which were enhanced ranging from 98% to 280% over the March 2009 average. Furthermore, significant increases in toxic air pollutants (e.g., gaseous elemental mercury (GEM) and dibenzo-p-dioxin/furan) concentrations were also observed, implying a severe impact from BB smoke on ecosystems and human health. The transport pathway and BB smoke layer height were investigated with backward trajectories, daily satellite aerosol products, and lidar observations. The mean SSA440 value of 0.87 suggested that the plume contained highly adsorbing aerosols, and the high char-EC/soot-EC ratio (low-temperature elemental carbon/high-temperature elemental carbon) of 29.4 suggested predominance of BB aerosols. In addition, plume aging indicators (e.g., GEM/CO, O3/CO, char-EC/soot-EC) suggest the BB plume was only weakly aged (i.e. low air mass intermixing, low chemical transformation, low cloud interaction) and in a nearly pristine state during the whole of the long-range transport. This event study can serve as a valuable benchmark when identifying unaged BB plumes that have been transported from PSEA to LABS (>2000 km) and will be useful for characterizing PSEA BB and its impact on greater Asia environment.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-13-5513-2020", "year": 2020, "title": "Satellite validation strategy assessments based on the AROMAT campaigns", "abstract": "Abstract. The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaigns took place in Romania in September 2014 and August 2015. They focused on two sites: the Bucharest urban area and large power plants in the Jiu Valley. The main objectives of the campaigns were to test recently developed airborne observation systems dedicated to air quality studies and to verify their applicability for the validation of space-borne atmospheric missions such as the TROPOspheric Monitoring Instrument (TROPOMI)/Sentinel-5 Precursor (S5P). We present the AROMAT campaigns from the perspective of findings related to the validation of tropospheric NO2, SO2, and H2CO. We also quantify the emissions of NOx and SO2 at both measurement sites. We show that tropospheric NO2 vertical column density (VCD) measurements using airborne mapping instruments are well suited for satellite validation in principle. The signal-to-noise ratio of the airborne NO2 measurements is an order of magnitude higher than its space-borne counterpart when the airborne measurements are averaged at the TROPOMI pixel scale. However, we show that the temporal variation of the NO2 VCDs during a flight might be a significant source of comparison error. Considering the random error of the TROPOMI tropospheric NO2 VCD (), the dynamic range of the NO2 VCDs field extends from detection limit up to 37 (2.61016 molec. cm2) and 29 (21016 molec. cm2) for Bucharest and the Jiu Valley, respectively. For both areas, we simulate validation exercises applied to the TROPOMI tropospheric NO2 product. These simulations indicate that a comparison error budget closely matching the TROPOMI optimal target accuracy of 25 % can be obtained by adding NO2 and aerosol profile information to the airborne mapping observations, which constrains the investigated accuracy to within 28 %. In addition to NO2, our study also addresses the measurements of SO2 emissions from power plants in the Jiu Valley and an urban hotspot of H2CO in the centre of Bucharest. For these two species, we conclude that the best validation strategy would consist of deploying ground-based measurement systems at well-identified locations.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-14-1205-2014", "year": 2014, "title": "On the relationship between Arctic ice clouds and polluted air masses over the North Slope of Alaska in April 2008", "abstract": "Abstract. Recently, two types of ice clouds (TICs) properties have been characterized using the Indirect and Semi-Direct Aerosol Campaign (ISDAC) airborne measurements (Alaska, April 2008). TIC-2B were characterized by fewer (< 10 L1) and larger (> 110 m) ice crystals, and a larger ice supersaturation (> 15%) compared to TIC-1/2A. It has been hypothesized that emissions of SO2 may reduce the ice nucleating properties of ice nuclei (IN) through acidification, resulting in a smaller concentration of larger ice crystals and leading to precipitation (e.g., cloud regime TIC-2B). Here, the origin of air masses forming the ISDAC TIC-1/2A (1 April 2008) and TIC-2B (15 April 2008) is investigated using trajectory tools and satellite data. Results show that the synoptic conditions favor air masses transport from three potential SO2 emission sources into Alaska: eastern China and Siberia where anthropogenic and biomass burning emissions, respectively, are produced, and the volcanic region of the Kamchatka/Aleutians. Weather conditions allow the accumulation of pollutants from eastern China and Siberia over Alaska, most probably with the contribution of acidic volcanic aerosol during the TIC-2B period. Observation Monitoring Instrument (OMI) satellite observations reveal that SO2 concentrations in air masses forming the TIC-2B were larger than in air masses forming the TIC-1/2A. Airborne measurements show high acidity near the TIC-2B flight where humidity was low. These results support the hypothesis that acidic coating on IN could be at the origin of the formation of TIC-2B.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.ENVRES.2015.09.020", "year": 2016, "title": "Urbanization and environmental change during the economic transition on the Mongolian Plateau: Hohhot and Ulaanbaatar", "abstract": "Driven by drastic socioeconomic changes in China and Mongolia, urbanization has become one of the most significant driving forces in the transformation of the Mongolian Plateau in the past 30 years. Using Hohhot and Ulaanbaatar as case studies, we developed a holistic approach to examine the socioeconomic and natural driving forces for urbanization and to investigate the impact on the urban environment. We used a multidisciplinary approach and relied on a variety of data sources to assess the changes of the landscape and environment of the two cities. We detected a rapid urbanization in Hohhot and Ulaanbaatar, both in terms of urban population growth and urban land expansion, from 1990 to 2010, with a much faster speed in 20002010. The local geo-physical conditions have constrained the spatial direction of expansion. Ulaanbaatar lagged behind Hohhot for about a decade when measured by indicators of urban population and urban land. Both cities have a degraded urban environment and a growing air pollution epidemic. While Hohhot had worse air pollution than Ulaanbaatar in the early 2000s, the gap between the two cities became smaller after 2010. The research presented here highlights the following as key determinants for urbanization and environmental change: (1) the co-evolution of urbanization, economic development, and environmental change; (2) the urbanization of transitional economies driven by the change of the economic structure, i.e., the development by both manufacturing and tertiary sectors and the change in the primary sector; and (3) the recent institutional changes and increased integration with the global economy.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS10110709", "year": 2019, "title": "Aerosol optical depth of the main aerosol species over italian cities based on the NASA/MERRA-2 model reanalysis", "abstract": "The Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2) provides data at 0.5 0.625 resolution covering a period from 1 January 1980 to the present. Natural and anthropogenic aerosols are simulated in MERRA-2, considering the Goddard chemistry, aerosol, radiation, and transport model. This model simulates the sources, sinks, and chemistry of mixed aerosol tracers: dust, sea salt, hydrophobic and hydrophilic black carbon and organic carbon, and sulfate. MERRA-2 aerosol reanalysis is a pioneering tool for investigating air quality issues, noteworthy for its global coverage and its distinction of aerosol speciation expressed in the form of aerosol optical depth (AOD). The aim of this work was to use the MERRA-2 reanalysis to study urban air pollution at a national scale by analyzing the AOD. AOD trends were evaluated for a 30-year period (19872017) over five Italian cities (Milan, Rome, Cagliari, Taranto, and Palermo) in order to investigate the impacts of urbanization, industrialization, air quality regulations, and regional transport on urban aerosol load. AOD evolution predicted by the MERRA-2 model in the period 20022017 showed a generalized decreasing trend over the selected cities. The anthropogenic signature on total AOD was between 50% and 80%, with the largest contribution deriving from sulfate.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/NHESS-10-2031-2010", "year": 2010, "title": "Design and installation of a Prototype Geohazard Monitoring System near Machu Picchu, Peru", "abstract": "Abstract. The town of Machu Picchu, Peru, serves the >700 000 tourists visiting Machu Picchu annually. It has grown threefold in population in the past two decades. Due to the limited low-lying ground, construction is occurring on the unstable valley slopes. Slopes range from <10 on the valley floor to >70 in the surrounding mountains. The town has grown on a delta formed at the confluence of the Alcamayo, Aguas Calientes and Vilcanota Rivers. Geohazards in and around the town of particular concern are 1) large rocks falling onto the town and/or the rail line, 2) flash flooding by any one of its three rivers, and 3) mudflows and landslides. A prototype early warning system that could monitor weather, river flow and slope stability was installed along the Aguas Calientes River in 2009. This has a distributed modular construction allowing components to be installed, maintained, salvaged, and repaired by local technicians. A diverse set of candidate power, communication and sensor technologies was evaluated. Most of the technologies had never been deployed in similar terrain, altitude or weather. The successful deployment of the prototype proved that it is technically feasible to develop early warning capacity in the town.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 9, "name": "Floods" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S13753-013-0008-8", "year": 2013, "title": "Evaluation of the visible and shortwave infrared drought index in China", "abstract": "In this article, the performance of the Visible and Shortwave infrared Drought Index (VSDI), a drought index recently developed and validated in Oklahoma, United States, is further explored and validated in China. The in-situ measured soil moisture from 585 weather stations across China are used as ground-truth data, and five commonly used drought indices are compared with VSDI for surface drought monitoring. The results reveal that VSDI is robust and reliable in the estimation of surface dryness-it has the highest correlation with soil moisture among the six indices when computed using both the original and cloud removed data. All six indices show the highest correlation with soil moisture at the 10 cm layer and the averaged 1050 cm layer. The spatiotemporal patterns of surface moisture indicated by the MODIS-based VSDI are further compared with the precipitation-based drought maps and the Global Land Data Assimilation System (GLDAS) simulated surface soil moisture maps over five provinces located in the Middle-Lower Yangtze Plain of China. The results indicate that despite the difference between the spatial and temporal resolutions of the three products, the VSDI maps still show good agreement with the other two drought products through the rapidly alternating drought and flood events in 2011 in this region. Therefore, VSDI can be used as an effective surface wetness indicator at both the provincial and the national scales in China.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1080/01431161.2014.945001", "year": 2014, "title": "The impact of large-scale forest fires on atmospheric aerosol characteristics", "abstract": "Aerosol optical thickness and aerosol index variations, caused by large-scale forest fires in central Yakutia in 2002 were studied using remote-sensing data (Earth Observing System (EOS) Terra, Earth Probe). Total emissions of CO2, CO, CH4, etc., were calculated using a modelling approach and Moderate Resolution Imaging Spectroradiometer (MODIS)/Terra burned area data. A comparison of the total emissions from forest fires in central Yakutia with global fire and volcanic emissions are made. Furthermore, long-range transport events of aerosol particles during maximum activity of forest fires are examined. It was shown that forest fires have a significant impact on the lower atmosphere; in particular, aerosol plumes are noticeable at a distance of around 3000 km from the study area.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S12517-016-2376-Z", "year": 2016, "title": "Spatio-temporal runoff estimation using TRMM satellite data and NRSC-CN method of a watershed of Upper Subarnarekha River basin, India", "abstract": "Geographical Information System (GIS) and Remote Sensing (RS) have acquired great significance in the recent years for estimation of runoff from watersheds and agricultural fields. This study has made use of the well-established tool, Natural Resources Conservation Service Curve Number (NRCS-CN) method to observe runoff over the study area in conjunction with GIS and RS. Pixel-wise runoff depth of the catchment was estimated by incorporating Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) data, Tropical Rainfall Measuring Mission (TRMM) multi-satellite precipitation analysis data for the years 20012011, and Landsat Enhanced Thematic Mapper (ETM)+ Land Use/Land Cover (LULC) information within the simple rainfall-runoff model. NRSC-CN was modified for Indian condition and the Hydrologic Engineering Centers Geospatial Hydrologic Modeling System (HEC-Geo-HMS) extension was utilized for evaluating the Curve Number (CN). Rainfall-Runoff model was executed to compute pixel-wise runoff, utilizing the model builder interface of ARC GIS 10. It was observed that there had been an increase in the average runoff depth ranging from 2.25 to 2.48 mm in different micro-watersheds of the study area. There was also an increase in total runoff depth from 61.24 to 68.47 m following an increase in mean CN value from 55 in the year 2001 to 57 in the year 2011. This indicated a lesser increase in lower runoff level range and a greater increase in higher runoff level range. In terms of runoff within the watershed, a higher percentage of its micro-watersheds showed lower runoff range compared to the micro-watersheds with higher runoff range. A direct correlation was observed between reduction in agriculture with increased runoff, increase in open land, and decrease in vegetation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ATMOSRES.2019.104763", "year": 2020, "title": "Exploring large-scale blackcarbon air pollution over Northern Eurasia in summer 2016 using MERRA-2 reanalysis data", "abstract": "The abnormally high temperature and the deficit of precipitation in Siberia in summer 2016 contributed to the development of massive forest fires, which resulted in pyrogenic emission in the atmosphere of various biomass burning products. This paper presents the analysis results of the spatial and temporal variations of black carbon (BC) in the atmosphere over Northern Eurasia during the 2016 Siberian wildfires using the MERRA-2 reanalysis data. The spatiotemporal evolution of BC anomalies is presented, with estimates of the increase in BC mass during wildfire period. The peculiarities of large-scale atmospheric circulation responsible for BC transport from Siberia to Central Europe are discussed. The estimates of spatial scale, effective height and speed of the long-range anomalous (from east to west) transfer of air masses in the atmosphere over Northern Eurasia in July 2016 are obtained. Changes in the optical and microphysical characteristics of biomass-burning aerosol during its long-range transport are also discussed. A comparison of daily variations in surface BC concentrations at the polar observatory Tiksi with those in BC column mass density from MERRA-2 revealed a high correlation between local and integral characteristics of BC during arriving air masses from Siberian wildfires.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JASTP.2018.01.022", "year": 2018, "title": "Modeling of tropospheric NO2 column over different climatic zones and land use/land cover types in South Asia", "abstract": "We have applied regression analyses for the modeling of tropospheric NO2 (tropo-NO2) as the function of anthropogenic nitrogen oxides (NOx) emissions, aerosol optical depth (AOD), and some important meteorological parameters such as temperature (Temp), precipitation (Preci), relative humidity (RH), wind speed (WS), cloud fraction (CLF) and outgoing long-wave radiation (OLR) over different climatic zones and land use/land cover types in South Asia during October 2004December 2015. Simple linear regression shows that, over South Asia, tropo-NO2 variability is significantly linked to AOD, WS, NOx, Preci and CLF. Also zone-5, consisting of tropical monsoon areas of eastern India and Myanmar, is the only study zone over which all the selected parameters show their influence on tropo-NO2 at statistical significance levels. In stepwise multiple linear modeling, tropo-NO2 column over landmass of South Asia, is significantly predicted by the combination of RH (standardized regression coefficient, = 49), AOD ( = 0.42) and NOx ( = 0.25). The leading predictors of tropo-NO2 columns over zones 15 are OLR, AOD, Temp, OLR, and RH respectively. Overall, as revealed by the higher correlation coefficients (r), the multiple regressions provide reasonable models for tropo-NO2 over South Asia (r = 0.82), zone-4 (r = 0.90) and zone-5 (r = 0.93). The lowest r (of 0.66) has been found for hot semi-arid region in northwestern Indus-Ganges Basin (zone-2). The highest value of for urban area AOD (of 0.42) is observed for megacity Lahore, located in warm semi-arid zone-2 with large scale crop-residue burning, indicating strong influence of aerosols on the modeled tropo-NO2 column. A statistical significant correlation (r = 0.22) at the 0.05 level is found between tropo-NO2 and AOD over Lahore. Also NOx emissions appear as the highest contributor ( = 0.59) for modeled tropo-NO2 column over megacity Dhaka.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ENVSOFT.2017.11.031", "year": 2018, "title": "Estimating the spatiotemporal variation of NO2 concentration using an adaptive neuro-fuzzy inference system", "abstract": "Statistical modelling has been successfully used to estimate the variations of NO2 concentration, but employing new modelling techniques can make these estimations far more accurate. To do so, for the first time in application to spatiotemporal air pollution modelling, we employed a soft computing algorithm called adaptive neuro-fuzzy inference system (ANFIS) to estimate the NO2 variations. Comprehensive data sets were investigated to determine the most effective predictors for the modelling process, including land use, meteorological, satellite, and traffic variables. We have demonstrated that using selected satellite, traffic, meteorological, and land use predictors in modelling increased the R2 by 21%, and decreased the root mean square error (RMSE) by 47% compared with the model only trained by land use and meteorological predictors. The ANFIS model found to have better performance and higher accuracy than the multiple regression model. Our best model, captures 91% of the spatiotemporal variability of monthly mean NO2 concentrations at 1 km spatial resolution (RMSE 1.49 ppb) in a selected area of Australia.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2017.09.003", "year": 2018, "title": "Simulation and analysis of synoptic scale dust storms over the Arabian Peninsula", "abstract": "Dust storms are among the most severe environmental problems in arid and semi-arid regions of the world. The predictability of seven dust events, viz. D1: April 24, 2014; D2: February 2324, 2015; D3: April 13, 2015; D4: March 2628, 2016; D5: August 35, 2016; D6: March 1314, 2017 and D7:March 1921, 2017, are investigated over the Arabian Peninsula using a regionally adapted chemistry transport model CHIMERE coupled with the Weather Research and Forecast (WRF) model. The hourly forecast products of particulate matter concentrations (PM10) and aerosol optical depths (AOD) are compared against both satellite-based (MSG/SEVRI RGB dust, MODIS Deep Blue Aerosol Optical Depth: DB-AOD, Ozone Monitoring Instrument observed UV Aerosol Absorption Index: OMI-AI) and ground-based (AERONET AOD) remote sensing products. The spatial pattern and the time series of the simulations show good agreement with the observations in terms of the dust intensity as well as the spatiotemporal distribution. The causative mechanisms of these dust events are identified by the concurrent analyses of the meteorological data. From these seven storms, five are associated with synoptic scale meteorological processes, such as prefrontal storms (D1 and D7), postfrontal storms of short (D2), and long (D3) duration types, and a summer shamal storm (D6). However, the storms D4 and D6 are partly associated with mesoscale convective type dust episodes known as haboobs. The socio-economic impacts of the dust events have been assessed by estimating the horizontal visibility, air quality index (AQI), and the dust deposition flux (DDF) from the forecasted dust concentrations. During the extreme dust events, the horizontal visibility drops to near-zero values co-occurred withhazardous levels of AQI and extremely high dust deposition flux (250 g cm 2 day 1).", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-10-1665-2017", "year": 2017, "title": "High-resolution mapping of the NO2 spatial distribution over Belgian urban areas based on airborne APEX remote sensing", "abstract": "Abstract. We present retrieval results of tropospheric nitrogen dioxide (NO2) vertical column densities (VCDs), mapped at high spatial resolution over three Belgian cities, based on the DOAS analysis of Airborne Prism EXperiment (APEX) observations. APEX, developed by a Swiss-Belgian consortium on behalf of ESA (European Space Agency), is a pushbroom hyperspectral imager characterised by a high spatial resolution and high spectral performance. APEX data have been acquired under clear-sky conditions over the two largest and most heavily polluted Belgian cities, i.e. Antwerp and Brussels on 15 April and 30 June 2015. Additionally, a number of background sites have been covered for the reference spectra. The APEX instrument was mounted in a Dornier DO-228 aeroplane, operated by Deutsches Zentrum fur Luft- und Raumfahrt (DLR). NO2 VCDs were retrieved from spatially aggregated radiance spectra allowing urban plumes to be resolved at the resolution of 60 80 m2. The main sources in the Antwerp area appear to be related to the (petro)chemical industry while traffic-related emissions dominate in Brussels. The NO2 levels observed in Antwerp range between 3 and 35 1015 molec cm2, with a mean VCD of 17.4 3.7 1015 molec cm2. In the Brussels area, smaller levels are found, ranging between 1 and 20 1015 molec cm2 and a mean VCD of 7.7 2.1 1015 molec cm2. The overall errors on the retrieved NO2 VCDs are on average 21 and 28 % for the Antwerp and Brussels data sets. Low VCD retrievals are mainly limited by noise (1 slant error), while high retrievals are mainly limited by systematic errors. Compared to coincident car mobile-DOAS measurements taken in Antwerp and Brussels, both data sets are in good agreement with correlation coefficients around 0.85 and slopes close to unity. APEX retrievals tend to be, on average, 12 and 6 % higher for Antwerp and Brussels, respectively. Results demonstrate that the NO2 distribution in an urban environment, and its fine-scale variability, can be mapped accurately with high spatial resolution and in a relatively short time frame, and the contributing emission sources can be resolved. High-resolution quantitative information about the atmospheric NO2 horizontal variability is currently rare, but can be very valuable for (air quality) studies at the urban scale.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S12237-016-0172-3", "year": 2017, "title": "Differential Impact of Anniversary-Severe Cyclones on the Water Quality of a Tropical Coastal Lagoon", "abstract": "Mapping spatio-temporal dynamics of suspended load in a lagoon before-during-after a cyclone is crucial for monitoring sudden nutrient enrichment and associated processes such as algal blooms and siltation. However, not all cyclones produce similar impact on a coastal lagoon, some trigger algal blooms after passage while others just increase the overall turbidity. Asias largest brackish water lagoon, Chilika Lagoon, India was hit by two anniversary-severe cyclones Phailin (12 October 2013) and Hudhud (12 October 2014) recently. Their impacts were analysed with respect to physical, biological and meteorological factors which favour or restrict a phytoplankton bloom after the passage of a storm. Moderate-resolution imaging spectroradiometer surface reflectance data were used to examine the spatio-temporal variability in total suspended sediment (TSS) and chlorophyll-a (Chl-a) concentration pre- and post-cyclone. Comparative results revealed that Phailin was associated with higher rainfall, wind speed and surface runoff compared with Hudhud. These factors contributed to higher TSS concentration in all sectors of the lagoon post-Phailin compared with post-Hudhud. Extreme TSS, limited light, high rainfall and runoff and increased flushing rate post-Phailin restricted the likelihood of a phytoplankton bloom in the lagoon, a commonly reported phenomenon after the passage of a cyclone. In contrast, sufficient light availability due to lower TSS, low runoff and flushing and stable wind supported a phytoplankton bloom post-Hudhud. The observed differential impacts were linked to the individual cyclones characteristics such as differences in landfall locations, wind speed, trajectory after the landfall, differences in rainfall rate and surface runoff and speed of passage.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/RS10101541", "year": 2018, "title": "Detecting Areas Vulnerable to Sand Encroachment Using Remote Sensing and GIS Techniques in Nouakchott, Mauritania", "abstract": "Sand dune advances poses a major threat to inhabitants and local authorities in the area of Nouakchott, Mauritania. Despite efforts to control dune mobility, accurate and adequate local studies are still needed to tackle sand encroachment. We have developed a Sand Dune Encroachment Vulnerability Index (SDEVI) to assess Nouakchotts vulnerability to sand dune encroachment. Said index is based on the geo-physical characteristics of the area (wind direction and intensity, slope and surface height, land use, vegetation or soil properties) with Geographic Information System (GIS) techniques that can support local authorities and decision-makers in implementing preventive measures or reducing impact on the population and urban infrastructures. In order to validate this new index, we use two remote sensing approaches: optical-Sentinel 2 and Synthetic Aperture Radar (SAR)Sentinel 1 data. Results show that the greatest vulnerability is located in the north-eastern part of Nouakchott, where local conditions favor the advance of sand in the city, although medium to high values are also found in the eastern part. Optical images enabled us to distinguish desert sand using the ratio between near infrared/blue bands, and SAR Coherence Change Detection (CCD) imagery was used to assess the degree of stability of those sand bodies. The nature of the SDEVI index allows us to currently assess which areas are vulnerable to sand encroachment since we use long data records. Nevertheless, optical and SAR remote sensing allow sand evolution to be monitored on a near real-time basis.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12517-018-3487-5", "year": 2018, "title": "Determination and prediction of standardized precipitation index (SPI) using TRMM data in arid ecosystems", "abstract": "Drought over a period threatens the water resources, agriculture, and socioeconomic activities. Therefore, it is crucial for decision makers to have a realistic anticipation of drought events to mitigate its impacts. Hence, this research aims at using the standardized precipitation index (SPI) to predict drought through time series analysis techniques. These adopted techniques are autoregressive integrating moving average (ARIMA) and feed-forward backpropagation neural network (FBNN) with different activation functions (sigmoid, bipolar sigmoid, and hyperbolic tangent). After that, the adequacy of these two techniques in predicting the drought conditions has been examined under arid ecosystems. The monthly precipitation data used in calculating the SPI time series (SPI 3, 6, 12, and 24 timescales) have been obtained from the tropical rainfall measuring mission (TRMM). The prediction of SPI was carried out and compared over six lead times from 1 to 6 using the model performance statistics (coefficient of correlation (R), mean absolute error (MAE), and root mean square error (RMSE)). The overall results prove an excellent performance of both predicting models for anticipating the drought conditions concerning model accuracy measures. Despite this, the FBNN models remain somewhat better than ARIMA models with R 0.7865, MAE 1.0637, and RMSE 1.2466. Additionally, the FBNN based on hyperbolic tangent activation function demonstrated the best similarity between actual and predicted for SPI 24 by 98.44%. Eventually, all the activation function of FBNN models has good results respecting the SPI prediction with a small degree of variation among timescales. Therefore, any of these activation functions can be used equally even if the sigmoid and bipolar sigmoid functions are manifesting less adjusted R2 and higher errors (MAE and RMSE). In conclusion, the FBNN can be considered a promising technique for predicting the SPI as a drought monitoring index under arid ecosystems.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.ATMOSENV.2018.04.052", "year": 2018, "title": "The deterioration of materials as a result of air pollution as derived from satellite and ground based observations", "abstract": "Dose Response Functions (DRFs) are widely used in estimating corrosion and/or soiling levels of materials used in building constructions and cultural monuments. These functions quantify the effects of air pollution and environmental parameters on different materials through ground based measurements of specific air pollutants and climatic parameters. Here, we propose a new approach where available satellite observations are used instead of ground-based data. Through this approach, the use of DRFs is expanded to cover situations where there are no in situ measurements, introducing also a totally new field where satellite data can be shown to be very helpful. In the present work satellite observations made by MODIS (MODerate resolution Imaging Spectroradiometer) on board Terra and Aqua, OMI (Ozone Monitoring Instrument) on board Aura and AIRS (Atmospheric Infrared Sounder) on board Aqua have been used.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.APR.2019.01.009", "year": 2019, "title": "Extended database of SO2 column densities over Pakistan by exploiting satellite observations", "abstract": "Increasing levels of atmospheric SO2 is a major threat and is now widely included in health risk assessment studies. An annual estimation of SO2 has been conducted for both anthropogenic and natural activities at country level. Satellite observations of atmospheric sulfur dioxide (SO2) are obtained over Pakistan during the time span of 20052016. The data was acquired from the Ozone Monitoring Instrument (OMI) onboard NASA's Aura satellite. DOAS (Differential Optical Absorption Spectroscopy) based algorithm was utilized to retrieve SO2 column densities. In addition to spatio-temporal analysis of SO2 column, seasonal cycles over major areas of Pakistan are evaluated and discussed. Year 2007, 2011 exhibited anomalous high levels of SO2 attributed to trans-boundary volcanic plumes observed in Pakistan. SO2 plumes were caused by Dallafilla and Nabro volcanic eruption and spread over East African, the Middle Eastern and South Asian regions. A temporal increase of about 78% was observed in anthropogenic SO2 levels for a period of 20052016 across Pakistan. Further, the relative change was maximum in Khyber Pakhtoon Khwa (KPK region 46%) followed by Punjab (38%), Sindh (28%) and Baluchistan (18%), respectively. The economic prosperity in recent years resulted in increased demand for energy by both the industrial and domestic sector, and consequent increase in SO2 emissions in Pakistan.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 18, "name": "Volcanic Eruptions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/ATMOS9120486", "year": 2018, "title": "Performance Evaluation of CCAM-CTM Regional Airshed Modelling for the New South Wales Greater Metropolitan Region", "abstract": "A comprehensive evaluation of the performance of the coupled Conformal Cubic Atmospheric Model (CCAM) and Chemical Transport Model (CTM) (CCAM-CTM) for the New South Wales Greater Metropolitan Region (NSW GMR) was conducted based on modelling results for two periods coinciding with measurement campaigns undertaken during the Sydney Particle Study (SPS), namely the summer in 2011 (SPS1) and the autumn in 2012 (SPS2). The model performance was evaluated for fine particulate matter (PM2.5), ozone (O3) and nitrogen dioxide (NO2) against air quality data from the NSW Governments air quality monitoring network, and PM2.5 components were compared with speciated PM measurements from the Sydney Particle Studys Westmead sampling site. The model tends to overpredict PM2.5 with normalised mean bias (NMB) less than 20%, however, moderate underpredictions of the daily peak are found on high PM2.5 days. The PM2.5 predictions at all sites comply with performance criteria for mean fractional bias (MFB) of 60%, but only PM2.5 predictions at Earlwood further comply with the performance goal for MFB of 30% during both periods. The model generally captures the diurnal variations in ozone with a slight underestimation. The model also tends to underpredict daily maximum hourly ozone. Ozone predictions across regions in SPS1, as well as in Sydney East, Sydney Northwest and Illawarra regions in SPS2 comply with the benchmark of MFB of 15%, however, none of the regions comply with the benchmark for mean fractional error (MFE) of 35%. The model reproduces the diurnal variations and magnitudes of NO2 well, with a slightly underestimating tendency across the regions. The MFE and normalised mean error (NME) for NO2 predictions fall well within the ranges inferred from other studies. Model results are within a factor of two of measured averages for sulphate, nitrate, sodium and organic matter, with elemental carbon, chloride, magnesium and ammonium being underpredicted. The overall performance of CCAM-CTM modelling system for the NSW GMR is comparable to similar model predictions by other regional airshed models documented in the literature. The performance of the modelling system is found to be variable according to benchmark criteria and depend on the location of the sites, as well as the time of the year. The benchmarking of CCAM-CTM modelling system supports the application of this model for air quality impact assessment and policy scenario modelling to inform air quality management in NSW.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ECSS.2019.02.038", "year": 2019, "title": "Long-term distribution patterns of remotely sensed water quality variables in Pearl River Delta, China", "abstract": "Pearl River Delta (PRD) is the third largest and one of the most productive Deltas in south China, where long-term monitoring and its assessment of water quality are necessary to understand the distribution patterns to infer the coastal zone management. The studies on long-term monitoring in water quality variable concerning the changing climate and anthropogenic effects can be made possible by continuous coverage of Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. This study attempts to study the long-term trends, quantitative measurements, and assessment of water quality variables including total suspended solids (TSS), diffuse attenuation coefficient for downwelling irradiance at 490 nm (Kd (490)), and sea surface temperature (SST) using 8-day composite and monthly data products of MODIS data for the period between July 2002 and August 2018 in the turbid waters of the PRD. Monthly products are used to quantify the variability of these water quality properties on long-term climatology, seasonal and as well as spatial distributions to interannual timescales. We observed a decreasing trend of TSS and Kd (490) between 2002 and 2018, though not significant, whereas, an increasing trend of SST has recorded for the PRD region during the same time. Seasonal patterns of TSS, Kd (490) and SST showed significant differences between the seasons. The high values of TSS (>15 gm3) and Kd (490) (>2 m1) were found in summer, autumn followed by winter, and low values (<0.5 gm 3 and 0.1 m-1) in spring. Consequently, high SSTs were noticed in the in summer-Autumn season and low SSTs in winter. The spatial concentrations of TSS, Kd (490) and SST were found high in the northern region and low values in the offshore and the southern part of the PRD. The increased values of TSS and Kd (490) in summer can be attributed to the high amount of precipitation, and strong monsoonal winds lead to the significant amounts of highly turbid waters in the water column. Based on the MODIS derived time series of TSS and Kd (490), a significant correlation with wind speed was found between these variables, suggesting a critical role of precipitation, river discharge and wind forcing in the variability of ocean variables in the PRD region.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/S11069-019-03714-0", "year": 2019, "title": "Comparative analysis of two rainfall retrieval algorithms during extreme rainfall event: a case study on cloudburst, 2010 over Ladakh (Leh), Jammu and Kashmir", "abstract": "Intense rainfall events lead to floods and landslides in the Western Himalayas (WH). These rainfall amounts are considered comparatively moderate over the plains. These events, called cloudbursts, are convective triggered followed by orographically locked phenomena producing sudden high-intensity rainfall over a small area. Early warning and prediction of such severe local weather systems is important to mitigate societal impacts arising from the accompanying flash floods, landslides, etc. Due to lack of ground-based observations, cloudbursts over remote and unpopulated hilly areas often go unreported. Present study examines a cloudburst occurred at Ladakh (Leh) in the WH in the early hours of August 5, 2010, using remotely sensed rainfall data from Tropical Rainfall Measuring Mission (TRMM) and Kalpana-1. The storm lasted for 2 days starting from August 3, 2010, followed by flash floods. Rain-band propagation over the region is studied from Kalpana-1 3-hourly rainfall estimates using Indian Satellite (INSAT) multi-spectral rainfall algorithm (IMSRA) and TRMM rainfall estimates using TRMM 3B42 algorithm. Quantitative and qualitative assessment and comparison of these two products is made. It is observed that there is decrease in satellite brightness temperature (BT) during the rainfall event. Initiation of rainfall occurs at about ", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S12595-019-00314-5", "year": 2020, "title": "Influence of Oceanographic Variability on the Life Cycle and Spawning Period of Sardinella fimbriata in the Northern Part of Bay of Bengal", "abstract": "Reproduction and distribution patterns of Sardinella fimbriata had responded differently to oceanographic changes in various parts of the world. This is the first report investigating the effects of oceanographic parameters on the maturation and spawning of S. fimbriata in the northern part of Bay of Bengal. Monthly precipitation rate, sea surface temperature (SST) and chlorophyll-a data were analyzed for possible correlation with Catch per Unit Effort (CPUE) of the fish species under study. Gonado-somatic Index, Gastro-somatic Index, and histology of the gonadal maturity stages were also studied. The peak spawning activity was found to take place during the period with the highest precipitation rate (r2 = 0.5006, p ", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JMARSYS.2020.103305", "year": 2020, "title": "The satellite derived environmental factors and their relationships with dimethylsulfide in the East Marginal Seas of China", "abstract": "Biogenic dimethylsulfide (DMS) sea-to-air flux and its closely linked environment factors are studied in the East Marginal Seas of China (EMSC) (25N-40N, 120E-130E) from 2011 to 2015. Higher chlorophyll-a (CHL) up north during blooming season is due to the southeasterly wind brought more nutrients from the Changjiang River waters. The elevated CHL during autumn and winter periods down south is more related with the higher sea surface temperature (SST). The lower CHL in the middle region in the later half year was mainly influenced by terrestrial runoff and the diluted Changjiang River waters. The enriched Changjiang River discharges brought more nutrients to the Zhejiang coastal waters and enriched the local phytoplankton, where aerosol optical depth (AOD) had the highest correlation with CHL (0.96). Peak SST was in August and had a negative correlation with wind speed (WIND). With increased WIND up north, AOD reduced accordingly. Lower CHL in 2015 was mainly related to the southeastern wind brought less nutrient water from Open Sea during blooming season. DMS sea-to-air fluxes are calculated and compared with OUC (Ocean University of China) field data. The reasonable agreements are made. DMS concentrations ranged from 0.32 to 5.64 nM with a mean of 2.19 nM, it had high positive correlations with CHL in the summer and autumn periods. DMS sea-to-air fluxes ranged within 2.1459.06 molm2d1 with a mean of 18.96 molm2d1. The elevated DMS sea-to-air fluxes in ECMS indicate the contributions of DMS emission in the study region cannot be ignored on the global climate evaluation.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2020EA001315", "year": 2020, "title": "How Accurately Can Satellite Products (TMPA and IMERG) Detect Precipitation Patterns, Extremities, and Drought Across the Nepalese Himalaya?", "abstract": "This study aims to assess the accuracy of two satellite-based precipitation products (SBPPs), that is, Tropical Rainfall Measurement Mission (TRMM)-based Multi-satellite Precipitation Analysis (TMPA) and its upgraded version Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (IMERG), in capturing spatial and temporal variation of precipitation and their application for extreme events (high-intensity precipitation and drought). They were evaluated against 142-gauge stations from Nepal during 20012018. The results show that, in general, both SBPPs show the overall characteristics of precipitation patterns, although underestimated the mean annual precipitation during the study period. It was also noted that IMERG product yields better performance to detect precipitation events (probability of detection) and no-precipitation events (false alarm ratio) than TMPA. Based on four different extreme precipitation indices: heavy precipitation events (R10mm), extreme precipitation events (R25mm), five consecutive dry days (CDD), and five consecutive wet days (CWD), it was observed that the SBPPs underestimated the frequency of R25mm and CDD spells while overestimated R10mm and CWD spells. Additionally, both SBPPs exhibited considerable capabilities in capturing the drought events during the study period. Overall, the drought event, bias, and frequency show that the IMERG product has slightly better capabilities to capture drought than the TMPA product. In general, IMERG was found to be superior at a daily timescale, while TMPA shows consistent performance on a monthly scale during the study period. Furthermore, there is still space for further improvement of IMERG rainfall retrieval algorithms.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.ATMOSENV.2019.117150", "year": 2020, "title": "Carbonaceous aerosol emission reduction over Shandong province and the impact of air pollution control as observed from synthetic satellite data", "abstract": "Aerosol loading and trace gas emissions from agriculture crop residue burning has been one of the main factors leading to the deterioration of air quality especially during the harvest time in China. Here, we evaluate the contribution of atmospheric aerosol loading from biomass burning and its relationship to the air pollution control policy. We focused on Shandong province, China because it has the highest level of agriculture burning pollution in October. Satellite-based data related to biomass burning including aerosol optical depth (AOD) and fire pixel counts from Moderate Resolution Imaging Spectroradiometer (MODIS), carbon monoxide (CO) from Measurements Of Pollution In The Troposphere (MOPITT), aerosol index (AI) and tropospheric NO2 from Ozone Monitoring Instrument (OMI), and aerosol layer depths from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO). These metrics were synthetically utilized to evaluate spatial and temporal variation of atmospheric aerosols during the agriculture crop residue burning month from 2006 to 2017. Carbonaceous aerosol emission reduction and the impact of the air pollution control policy can be found in the CALIPSO aerosol types and MODIS fire pixel counts data. The AOD, NO2, CO, and AI over three different land covers (cropland, forest and impervious surfaces) were further obtained according to the land cover data set. The results indicated that there was an obvious decrease in all carbonaceous aerosol-related quantities after year 2012 when the local government began to enact and implement strict air pollution control policies, although a period (23 years) of transition after the policy implementation time was identified. We also found that CO is stable and low over the cropland versus forest and impervious surfaces; NO2 exhibits a continuously high value in the northern areas of the oil field. The impact of industry activity rather than straw burning should be also considered for NO2 and CO in certain areas.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S10113-019-01514-7", "year": 2019, "title": "Interannual lake fluctuations in the Argentine Puna: relationships with its associated peatlands and climate change", "abstract": "High elevation ecosystems are likely more sensitive to climate change. But, due to paucity of instrumental records, such effects are poorly studied, particularly in mountains outside Europe and North America. Here, we quantified water body area fluctuations for the last 32 years in 15 lakes spread over an area of 14.3 million ha in the Argentine Puna, through the classification of Landsat images; and we quantified peatlands NDVI (a proxy of vegetation productivity) from MODIS images. We evaluated the pairwise similarity between lakes interannual fluctuations and their relationship with climate models (TRMM 3B43 v7; CRU TS 4.10) and potential controls (ENSO index); and the correlations between water body area and the NDVI variation of its associated peatlands. Lakes were grouped in two clusters defined by their synchronic water body area variability and these clusters define two main geographic zones: NE and SW. Consistent with previous observations of an overall aridization trend, water body area generally decreased but showed large variability among lakes. Peatlands productivity was more correlated with lake variability than with modeled precipitation, and lake water body area was weakly related to indices of ENSO, providing an additional tool to relate local climate with continental and global climate models. The analysis shows that lake behavior is highly variable spatially and temporally, and that satellite-based monitoring is a valuable tool for assessing ecological conditions of wetlands in the region, characterized by the lack of climatic instrumental records; and to explore the vulnerability of wetlands to climate change.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1073/PNAS.1714597115", "year": 2018, "title": "High fire-derived nitrogen deposition on central African forests", "abstract": "Atmospheric nitrogen (N) deposition is an important determinant of N availability for natural ecosystems worldwide. Increased anthropogenic N deposition shifts the stoichiometric equilibrium of ecosystems, with direct and indirect impacts on ecosystem functioning and biogeochemical cycles. Current simulation data suggest that remote tropical forests still receive low atmospheric N deposition due to a lack of proximate industry, low rates of fossil fuel combustion, and absence of intensive agriculture. We present field-based N deposition data for forests of the central Congo Basin, and use ultrahigh-resolution mass spectrometry to characterize the organic N fraction. Additionally, we use satellite data and modeling for atmospheric N source apportionment. Our results indicate that these forests receive 18.2 kg N hectare1 years1 as wet deposition, with dry deposition via canopy interception adding considerably to this flux. We also show that roughly half of the N deposition is organic, which is often ignored in N deposition measurements and simulations. The source of atmospheric N is predominantly derived from intensive seasonal burning of biomass on the continent. This high N deposition has important implications for the ecology of the Congo Basin and for global biogeochemical cycles more broadly.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S10346-018-1008-Y", "year": 2018, "title": "Landslide inventory for hazard assessment in a data-poor context: a regional-scale approach in a tropical African environment", "abstract": "Landslide hazard remains poorly characterized on regional and global scales. In the tropics in particular, the lack of knowledge on landslide hazard is in sharp contrast with the high landslide susceptibility of the region. Moreover, landslide hazard in the tropics is expected to increase in the future in response to growing demographic pressure and climate and land use changes. With precipitation as the primary trigger for landslides in the tropics, there is a need for an accurate determination of rainfall thresholds for landslide triggering based on regional rainfall information as well as reliable data on landslide occurrences. Here, we present the landslide inventory for the central section of the western branch of the East African Rift (LIWEAR). Specific attention is given to the spatial and temporal accuracy, reliability, and geomorphological meaning of the data. The LIWEAR comprises 143 landslide events with known location and date over a span of 48 years from 1968 to 2016. Reported landslides are found to be dominantly related to the annual precipitation patterns and increasing demographic pressure. Field observations in combination with local collaborations revealed substantial biases in the LIWEAR related to landslide processes, landslide impact, and the remote context of the study area. In order to optimize data collection and minimize biases and uncertainties, we propose a three-phase, Search-Store-Validate, workflow as a framework for data collection in a data-poor context. The validated results indicate that the proposed methodology can lead to a reliable landslide inventory in a data-poor context, valuable for regional landslide hazard assessment at the considered temporal and spatial resolutions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1080/02626667.2018.1557335", "year": 2019, "title": "Hydrological appraisal of rainfall estimates from radar, satellite, raingauge and satellitegauge combination on the Qinhuai River Basin, China", "abstract": "Multisource rainfall products can be used to overcome the absence of gauged precipitation data for hydrological applications. This study aims to evaluate rainfall estimates from the Chinese S-band weather radar (CINRAD-SA), operational raingauges, multiple satellites (CMORPH, ERA-Interim, GPM, TRMM-3B42RT) and the merged satellitegauge rainfall products, CMORPH-GC, as inputs to a calibrated probability distribution model (PDM) on the Qinhuai River Basin in Nanjing, China. The Qinhuai is a middle-sized catchment with an area of 799 km2. All sources used in this study are capable of recording rainfall at high spatial and temporal resolution (3 h). The discrepancies between satellite and radar data are analysed by statistical comparison with raingauge data. The streamflow simulation results from three flood events suggest that rainfall estimates using CMORPH-GC, TRMM-3B42RT and S-band radar are more accurate than those using the other rainfall sources. These findings indicate the potential to use satellite and radar data as alternatives to raingauge data in hydrological applications for ungauged or poorly gauged basins.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.4401/AG-7600", "year": 2018, "title": "Observations of Precipitable Water Vapor along the Maritime Continent Associated with El Nino-Southern Oscillation Activity", "abstract": "The effect of El Nino and La Nina events is a major issue in the regional climate of Southeast Asia. This study uses the Precipitable Wa- ter Vapor (PWV) values estimated from Global Navigation Satellite System (GNSS; in particular Global Positioning System, GPS) to in- vestigate the El Nino-Southern Oscillation (ENSO) activity in the Southern coast of the South China Sea (SCS). For this study, GPS and meteorological systems are installed at the Universiti Malaysia Sabah, Kota Kinabalu (UMSK), which is located on the coast of the mar- itime continent. Subsequently, PWV from GPS and PWV obtained from Radiosonde, prior to the investigation of ENSO activity, are com- pared. To further investigate the relationship between PWV and ENSO activities, data from three additional GPS stations located along the coast of SCS during the 3-year period 2009-2011 were analyzed. The selection period considers the availability of GPS data. The obtained results show that during the increased intensity of El Nino in 2009/2010, PWV decreases and drops about 10-week later, i.e., after the sea surface temperature anomaly (SSTa) has peaked. PWV has a negative correlation with the El Nino index, which is comparable with pre- cipitation data obtained from NASAs Tropical Rainfall Measuring Mission (TRMM). In contrast, the amount of PWV was increased dur- ing the La Nina event of 2010/2011. This observation suggests the GPS is a suitable technique for studying the ENSO activity.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JAG.2017.11.003", "year": 2018, "title": "A novel cross-satellite based assessment of the spatio-temporal development of a cyanobacterial harmful algal bloom", "abstract": "As the frequency of cyanobacterial harmful algal blooms (CyanoHABs) become more common in recreational\nlakes and water supply reservoirs, demand for rapid detection and temporal monitoring will be imminent for\neffective management. The goal of this study was to demonstrate a novel and potentially operational cross-\nsatellite based protocol for synoptic monitoring of rapidly evolving and increasingly common CyanoHABs in\ninland waters. The analysis involved a novel way to cross-calibrate a chlorophyll-a (Chl-a) detection model for\nthe Landsat-8 OLI sensor from the relationship between the normalized difference chlorophyll index and the\nfloating algal index derived from Sentinel-2A on a coinciding overpass date during the summer CyanoHAB\nbloom in Utah Lake. This aided in the construction of a time-series phenology of the Utah Lake CyanoHAB event.\nSpatio-temporal cyanobacterial density maps from both Sentinel-2A and Landsat-8 sensors revealed that the\nbloom started in the first week of July 2016 (July 3rd, mean cell count: 9163 cells/mL), reached peak in mid-\nJuly (July 15th, mean cell count: 108176 cells/mL), and reduced in August (August 24th, mean cell count: 9145\ncells/mL). Analysis of physical and meteorological factors suggested a complex interaction between landscape\nprocesses (high surface runoff), climatic conditions (high temperature, high rainfall followed by negligible\nrainfall, stable wind), and water quality (low water level, high Chl-a) which created a supportive environment\nfor triggering these blooms in Utah Lake. This cross satellitebased monitoring methods can be a great tool for\nregular monitoring and will reduce the budget cost for monitoring and predicting CyanoHABs in large lakes.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.RSMA.2019.100598", "year": 2019, "title": "Spatio-temporal dynamics of phytoplankton functional groups in the South China Sea and their relative contributions to marine primary production", "abstract": "The sea-surface distribution of four phytoplankton functional groups in the South China Sea (SCS) namely Coccolithophores (Coc), Diatoms (Dia), Cyanobacteria (Cya) and Chlorophytes (Chlo) was studied across spatial and temporal scales. The time-series datasets derived from the National Aeronautic and Space Administration (NASA) Ocean Biogeochemical Model and retrieved via the Giovanni Portal were analysed statistically with well-known methods including Pearsons correlation coefficient, ordinary least square regression (OLR), Maximum Entropy Spectral Analysis (MESA) and Principal Components Analysis (PCA). The data were analysed for relative abundance, seasonality, cyclicity, long-term trends, spatial variability, inter-relationships, and relative contributions of individual phytoplankton groups to primary production (PP, using Chl-a as a proxy). The results reveal that the numerically dominant phytoplankton group in terms of relative abundance is Cya, comprising about 57% of the planktonic biomass, followed closely by Coc (about 40%), while Dia constitutes almost 3% of the total abundance. Dia was found to have the strongest annual cycle, and hence displayed the highest rate of seasonal variability. Clear spatial segregation patterns have also been uncovered; Coc and Dia are strongly correlated in the Northern SCS (NSCS) while Cya dominate in Southern SCS (SSCS). Coc and Dia display a strong positive correlation with PP, whereas the seasonal relationships between Cya and Chlo with PP are non-linear, and hence appear statistically non-significant. The rise in the trend of Cya and decrease in Coc, since 2004, may be indicative of changes in successional patterns of phytoplankton functional groups in the SCS. This study, therefore, sets the precedence for more robust research to uncover the immediate and remote causes of the observed spatiotemporal changes in marine phytoplankton dynamics and to develop predictive models of marine primary productivity (MPP) and ecological health.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/HYDROLOGY6020038", "year": 2019, "title": "Spatio-Temporal Rainfall Variability and Flood Prognosis Analysis Using Satellite Data over North Bihar during the August 2017 Flood Event", "abstract": "Flooding is one of the most common natural disasters in India. Typically, the Kosi and Gandak river basins are well-known for lingering flood affected basins in North Bihar every year, which lies in the eastern part of India. There were no such comprehensive studies available in North Bihar that discussed flood progression and regression at shorter time-scales like two day intervals. So in this study, we employed high temporal resolution data to capture inundation extent and further, the flood extent has been validated with high spatial resolution data. The specific objective of this study was to analyze the satellite-derived Near Real Time (NRT) MODIS flood product for spatiotemporal mapping of flood progression and regression over the North Bihar. The synthetic aperture RADAR (SAR) data were also used to validate the MODIS NRT Flood data. As a case study, we selected a recent flood event of AugustSeptember 2017 and captured the flood inundation spatial extent at two day intervals using the 2 day composite NRT flood data. The flood prognosis analysis has revealed that during the peak flooding period, 12% to 17% of the area was inundated and the most adversely affected districts were Darbhanga and Katihar in North Bihar. We estimated that in total nearly 6.5% area of the North Bihar was submerged. The method applied was simple, but it can still be suitable to be applied by the community involved in flood hazard management, not necessarily experts in hydrological modeling. It can be concluded that the NRT MODIS flood product was beneficial to monitor flood prognosis over a larger geographical area where observational data are limited. Nevertheless, it was noticed that the flood extent area derived from MODIS NRT data has overestimated areal extent, but preserved the spatial pattern of flood. Apparently, the present flood prognosis analysis can be improved by integrating microwave remote sensing data (SAR) and hydrological models.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/QJ.2983", "year": 2017, "title": "Role of interactions between cloud microphysics, dynamics and aerosol in the heavy rainfall event of June 2013 over Uttarakhand, India", "abstract": "In this study, we propose a hypothesis, supported by numerical model simulations, concerning the role of cloud microphysical processes and aerosols in the invigoration of an extreme rainfall event over Uttarakhand in June 2013. The interactions among dynamics, thermodynamics and microphysical processes and their feedbacks play a vital role in the occurrence of extreme events. To test the proposed hypothesis, Weather Research and Forecasting (WRF) simulations are carried out with three different microphysical schemes (i.e. WDM6, Morrison, and CLR). The role of aerosol indirect effects in the process of invigoration of precipitation is demonstrated with a high-resolution regional model for the extreme event over the foothills of the Himalayas. The extreme event is characterized by the strong northsouth tropospheric temperature gradient and strong moisture convergence. Forced uplift beyond the freezing level initiates a precipitation process which involves cloud ice and mixed-phase cloud microphysics and latent heat release; further, it invigorates convection and enhances precipitation. Results pinpoint that the role of microphysical processes are very crucial during such a type of extreme event. Additionally, the result accentuates the importance of aerosols on the deep convective cloud systems which have influence through invigoration and involvement of complex interactions between aerosol, large-scale dynamics and cloud microphysics.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.AEOLIA.2015.02.004", "year": 2015, "title": "Dust emission and environmental changes in the dried bottom of the Aral Sea", "abstract": "In the 1990s, the western world became aware of the ecological disaster of what was once the fourth largest lake in the world the Aral Sea. The drastic desiccation of the Aral Sea led to the intensive development of desertification processes in the region and the formation of a new desert, the Aralkum. In the last few decades, the Aralkum has become the new hot spot of dust and salt storms in the region. Dust storms and their source areas have been determined and analyzed by the NOAA AVHRR, TOMS and OMI data. An analysis of the land-cover changes in the dried bottom of the Aral Sea revealed that the north-eastern part of the Aralkum Desert is one of the most active dust sources in the region, responsible for high aerosol concentrations in the atmosphere. Dust plumes that sweep up from the dried bottom of the Aral Sea have become larger, and dust storms have become more powerful, since the bottom exposure. The main change that occurred in the land cover was the considerable reduction of vegetation and small water bodies, while the areas of solonchaks (salty pans) and sandy massifs increased significantly.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 1, "name": "Air Quality" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.EPSL.2015.06.014", "year": 2015, "title": "Volcanic ash fall events identified using principal component analysis of a high-resolution speleothem trace element dataset", "abstract": "Large multivariate trace element datasets produced by LA-ICP-MS speleothem analysis can pose difficulties for analysis and interpretation. Processes acting on various timescales and magnitudes affect trace element concentrations, and deconvolving the most important controls is often complex. Here Principal Component Analysis (PCA) is applied to identify the modes and timings of variation which best explain the overall variability in an exceptionally high-resolution (10 m vertical resolution) multivariate trace element record produced by LA-ICP-MS from a modern (19792001) Belizean stalagmite with excellent age control. Principal Component 1 (PC1) in this dataset is defined by a weak correlation between multiple elements, and may reflect non-carbonate material incorporated within the speleothem. Elevated PC1 scores in ATM-7 occur following regional volcanic eruptions with ash clouds extending over the cave site, as demonstrated using NASA remote sensing data from the Total Ozone Mapping Spectrometer and HYSPLIT trajectory modelling. Spikes in PC1 occur at the beginning of the wet season, and this may reflect a seasonal flushing event that transports volcanogenic material through the karst and incorporates it within the speleothem. Our results suggest that PCA can simplify exploration of large laser ablation datasets, and that PCA is a valuable tool for identifying the dominant controls on stalagmite trace element chemistry. Future studies should evaluate how transferable this technique is to other sites with different environmental conditions where volcanic ashfall has occurred. This research potentially adds tephrochronology to the stalagmite dating toolkit or, conversely, opens the door to using stalagmites to identify previously unknown or uncertainly dated eruptions.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/RS70201504", "year": 2015, "title": "Evaluation of Six High-Resolution Satellite and Ground-Based Precipitation Products over Malaysia", "abstract": "Satellite precipitation products (SPPs) potentially constitute an alternative to sparse rain gauge networks for assessing the spatial distribution of precipitation. However, applications of these products are still limited due to the lack of robust quality assessment. This study compares daily, monthly, seasonal, and annual rainfall amount at 342 rain gauges over Malaysia to estimations using five SPPs (3B42RT, 3B42V7, GPCP-1DD, PERSIANN-CDR, and CMORPH) and a ground-based precipitation product (APHRODITE). The performance of the precipitation products was evaluated from 2003 to 2007 using continuous (RMSE, R2, ME, MAE, and RB) and categorical (ACC, POD, FAR, CSI, and HSS) statistical approaches. Overall, 3B42V7 and APHRODITE performed the best, while the worst performance was shown by GPCP-1DD. 3B42RT, 3B42V7, and PERSIANN-CDR slightly overestimated observed precipitation by 2%, 4.7%, and 2.1%, respectively. By contrast, APHRODITE and CMORPH significantly underestimated precipitations by 19.7% and 13.2%, respectively, whereas GPCP-1DD only slightly underestimated by 2.8%. All six precipitation products performed better in the northeast monsoon than in the southwest monsoon. The better performances occurred in eastern and southern Peninsular Malaysia and in the north of East Malaysia, which receives higher rainfall during the northeast monsoon, whereas poor performances occurred in the western and dryer Peninsular Malaysia. All precipitation products underestimated the no/tiny (<1 mm/day) and extreme (20 mm/day) rainfall events, while they overestimated low (120 mm/day) rainfall events. 3B42RT and 3B42V7 showed the best ability to detect precipitation amounts with the highest HSS value (0.36). Precipitations during flood events such as those which occurred in late 2006 and early 2007 were estimated the best by 3B42RT and 3B42V7, as shown by an R2 value ranging from 0.49 to 0.88 and 0.52 to 0.86, respectively. These results on SPPs uncertainties and their potential controls might allow sensor and algorithm developers to deliver better products for improved rainfall estimation and thus improved water management.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12040-016-0693-Y", "year": 2016, "title": "Impact of high resolution land surface initialization in Indian summer monsoon simulation using a regional climate model", "abstract": "The direct impact of high resolution land surface initialization on the forecast bias in a regional climate model in recent years over Indian summer monsoon region is investigated. Two sets of regional climate model simulations are performed, one with a coarse resolution land surface initial conditions and second one used a high resolution land surface data for initial condition. The results show that all monsoon years respond differently to the high resolution land surface initialization. The drought monsoon year 2009 and extended break periods were more sensitive to the high resolution land surface initialization. These results suggest that the drought monsoon year predictions can be improved with high resolution land surface initialization. Result also shows that there are differences in the response to the land surface initialization within the monsoon season. Case studies of heat wave and a monsoon depression simulation show that, the model biases were also improved with high resolution land surface initialization. These results show the need for a better land surface initialization strategy in high resolution regional models for monsoon forecasting.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSE.2016.04.019", "year": 2016, "title": "Mapping and quantifying Sargassum distribution and coverage in the Central West Atlantic using MODIS observations", "abstract": "Sargassum washing ashore on the beaches of the Caribbean Islands since 2011 has caused problems for the local environments, tourism, and economies. Although preliminary results of Sargassum distributions in the nearby oceans have been obtained using measurements from the Medium Resolution Imaging Spectrometer (MERIS), MERIS stopped functioning in 2012, and detecting and quantifying Sargassum distributions still face technical challenges due to ambiguous pixels from clouds, cloud shadows, cloud adjacency effect, and large-scale image gradient. In this paper, a novel approach is developed to detect Sargassum presence and to quantify Sargassum coverage using the Moderate Resolution Imaging Spectroradiometer (MODIS) alternative floating algae index (AFAI), which examines the red-edge reflectance of floating vegetation. This approach includes three basic steps: 1) classification of Sargassum-containing pixels through correction of large-scale gradient, masking clouds and cloud shadows, and removal of ambiguous pixels; 2) linear unmixing of Sargassum-containing pixels; and, 3) statistics of Sargassum area coverage in pre-defined grids at monthly, seasonal, and annual intervals. In the absence of direct field measurements to validate the results, limited observations from the Hyperspectral Imager for the Coastal Ocean (HICO) measurements and numerous local reports support the conclusion that the elevated AFAI signals are due to the presence of Sargassum instead of other floating materials, and various sensitivity analyses are used to quantify the uncertainties in the derived Sargassum area coverage. The approach was applied to MODIS observations between 2000 and 2015 over the Central West Atlantic (CWA) region (022N, 6338W) to derive the spatial and temporal distribution patterns as well as the total area coverage of Sargassum. Results indicate that the first widespread Sargassum distribution event occurred in 2011, consistent with previous MERIS findings. Since 2011, only 2013 showed a minimal Sargassum coverage similar to the period of 2000 to 2010; all other years showed significantly more coverage. More alarmingly, the summer months of 2015 showed mean coverage of >2000km2, or about 4 times of the summer 2011 coverage and 20 times of the summer 2000 to 2010 coverage. Analysis of several environmental variables provided some hints on the reasons causing the inter-annual changes after 2010, yet further multi-disciplinary research (including in situ measurements) is required to understand such changes and long-term trends in Sargassum coverage.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11356-015-5629-6", "year": 2016, "title": "Seasonal, interannual, and long-term variabilities in biomass burning activity over South Asia", "abstract": "The seasonal, interannual, and long-term variations in biomass burning activity and related emissions are not well studied over South Asia. In this regard, active fire location retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), the retrievals of aerosol optical depth (AOD) from MODIS Terra, and tropospheric column NO2 from Ozone Monitoring Instrument (OMI) are used to understand the effects of biomass burning on the tropospheric pollution loadings over South Asia during 20032013. Biomass burning emission estimates from Global Fire Emission Database (GFED) and Global Fire Assimilation System (GFAS) are also used to quantify uncertainties and regional discrepancies in the emissions of carbon monoxide (CO), nitrogen oxide (NOx), and black carbon (BC) due to biomass burning in South Asia. In the Asian continent, the frequency of fire activity is highest over Southeast Asia, followed by South Asia and East Asia. The biomass burning activity in South Asia shows a distinct seasonal cycle that peaks during February-May with some differences among four (north, central, northeast, and south) regions in India. The annual biomass burning activity in north, central, and south regions shows an increasing tendency, particularly after 2008, while a decrease is seen in northeast region during 20032013. The increase in fire counts over the north and central regions contributes 24 % of the net enhancement in fire counts over South Asia. MODIS AOD and OMI tropospheric column NO2 retrievals are classified into high and low fire activity periods and show that biomass burning leads to significant enhancement in tropospheric pollution loading over both the cropland and forest regions. The enhancement is much higher (110176 %) over the forest region compared to the cropland (3462 %) region. Further efforts are required to understand the implications of biomass burning on the regional air quality and climate of South Asia.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JASTP.2016.10.006", "year": 2016, "title": "The solar dimming/brightening effect over the Mediterranean Basin in the period 19792012", "abstract": "Numerous studies have shown that the solar radiation reaching the Earth's surface is subjected to multi-decadal variations with significant spatial and temporal heterogeneities in both magnitude and sign. Although several studies have examined the solar radiation trends over Europe, North America and Asia, the Mediterranean Basin has not been studied extensively. This work investigates the evolution and trends in the surface net short-wave radiation (NSWR, surface solar radiation - reflected) over the Mediterranean Basin during the period 19792012 using monthly re-analysis datasets from the Modern Era Retrospective-Analysis for Research and Applications (MERRA) and aims to shed light on the specific role of clouds on the NSWR trends. The solar dimming/brightening phenomenon is temporally and spatially analyzed over the Mediterranean Basin. The spatially-averaged NSWR over the whole Mediterranean Basin was found to increase in MERRA by +0.36Wm2 per decade, with higher rates over the western Mediterranean (+0.82Wm2 per decade), and especially during spring (March-April-May; +1.3Wm2 per decade). However, statistically significant trends in NSWR either for all-sky or clean-sky conditions are observed only in May. The increasing trends in NSWR are mostly associated with decreasing ones in cloud optical depth (COD), especially for the low (<700hPa) clouds. The decreasing COD trends (less opaque clouds and/or decrease in absolute cloudiness) are more pronounced during spring, thus controlling the increasing tendency in NSWR. The NSWR trends for cloudless (clear) skies are influenced by changes in the water-vapor content or even variations in surface albedo to a lesser degree, whereas aerosols are temporally constant in MERRA. The slight negative trend (not statistically significant) in NSWR under clear skies for nearly all months and seasons implies a slight increasing trend in water vapor under a warming and more humid climatic scenario over the Mediterranean.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.RSE.2014.06.013", "year": 2015, "title": "Coupling remote sensing bio-optical and three-dimensional hydrodynamic modeling to study the phytoplankton dynamics in a tropical hydroelectric reservoir", "abstract": "The goal of this study was to determine the extent to which mixing and stratification processes influence the horizontal surface phytoplankton distribution in a tropical hydroelectric reservoir in Brazil. We used a synergistic approach that combines remote sensing bio-optical empirical and three-dimensional hydrodynamic modeling to represent phytoplankton dynamics. Seasonal differences were evaluated by simulating the bio-optical and the three-dimensional hydrodynamic models for two periods: the austral summer and winter of 2009. The three-dimensional hydrodynamic model simulations showed that the water column was completely mixed during winter; the water column remained stratified during summer. We also noticed a permanent thermocline during the summer between 15 and 25m in the reservoir. In both seasons, the surface current was wind driven and preferentially directed eastward. The bio-optical model showed that the horizontal surface phytoplankton distribution, as indicated by chlorophyll-a concentration, was heterogeneous during winter and homogenous during summer. Moreover, higher concentrations were observed by the empirical bio-optical model during winter (the highest mean areal concentration was 24gL1) than in summer (2.1gL1). This difference was explained by short timescale events, such as cold front passages, which contributed to the proliferation of phytoplankton in winter by enhancing vertical mixing in the water column. Lake number analysis showed that upwelling events were the most common mechanisms driving the mixing process during winter (LN<1 82% of the time). Combining remote sensing and three-dimensional hydrodynamic modeling makes it possible to more fully analyze the dynamics of the horizontal surface phytoplankton distribution under different meteorological conditions. The two modeling techniques can be used in a complementary manner and serve as an essential tool for the environmental monitoring of aquatic systems.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/IJGI3020732", "year": 2014, "title": "Correlating Remote Sensing Data with the Abundance of Pupae of the Dengue Virus Mosquito Vector, Aedes aegypti, in Central Mexico", "abstract": "Using a geographic transect in Central Mexico, with an elevation/climate gradient, but uniformity in socio-economic conditions among study sites, this study evaluates the applicability of three widely-used remote sensing (RS) products to link weather conditions with the local abundance of the dengue virus mosquito vector, Aedes aegypti (Ae. aegypti). Field-derived entomological measures included estimates for the percentage of premises with the presence of Ae. aegypti pupae and the abundance of Ae. aegypti pupae per premises. Data on mosquito abundance from field surveys were matched with RS data and analyzed for correlation. Daily daytime and nighttime land surface temperature (LST) values were obtained from Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua cloud-free images within the four weeks preceding the field survey. Tropical Rainfall Measuring Mission (TRMM)-estimated rainfall accumulation was calculated for the four weeks preceding the field survey. Elevation was estimated through a digital elevation model (DEM). Strong correlations were found between mosquito abundance and RS-derived night LST, elevation and rainfall along the elevation/climate gradient. These findings show that RS data can be used to predict Ae. aegypti abundance, but further studies are needed to define the climatic and socio-economic conditions under which the correlations observed herein can be assumed to apply.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1002/2013JD021260", "year": 2014, "title": "Uncertainty of different atmospheric ozone retrievals and its effect on temporal trends and radiative transfer simulations in the Iberian Peninsula", "abstract": "AbstractUncertainty in total ozone column (TOC) values is quantified for eight different databases through a direct comparison with ground-based data at three Spanish locations, the maximum uncertainty being about 10.5 Dobson unit. A long-term TOC series is constructed using the mentioned databases from 1950 to 2011 for nine locations in the Iberian Peninsula. The monthly TOC climatology in the nine locations is presented. An exhaustive analysis is performed of TOC series trends and their statistical significance in the periods 19502011, 19501984, and 19852011. A significant ozone reduction between 1950 and 2011 appears in the Iberian Peninsula with a strong reduction from the late 1970s to the mid-1990s and with more or less constant or slightly increasing levels in the last 17 year. These trends are recalculated taking into account of uncertainty in the TOC values of the series, with a decrease in the number of statistically significant trends emerging. The statistically significant trends in annual and in the averaged Iberian Peninsula series are usually still significant even considering the uncertainty. Finally, a study is carried out of the uncertainty caused by TOC uncertainty in total shortwave and erythemal ultraviolet irradiances simulated under cloudless skies using a radiative transfer model.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/JGRD.50707", "year": 2013, "title": "Satellite-derived estimates of ultrafine particle concentrations over eastern North America", "abstract": "High concentrations of ultrafine particles (UFP, i.e., particles with diameter < 100 nm) impact both human health and Earth's climate. Recent innovations in remote sensing technologies and data retrievals offer the potential for predicting UFP concentrations based on data from satellite-borne instrumentation. Herein we present a physically based statistical algorithm to estimate UFP concentrations across eastern North America using remotely sensed aerosol optical depth, Angstrom exponent, ultraviolet solar radiation flux, and ammonia and sulfur dioxide concentrations. The proposed algorithm is built and independently evaluated using an array of in situ observations. The algorithm is able to capture up to 60% of the variability in daily measured UFP number concentrations at a regionally representative reference site and is thus applied to generate seasonal UFP concentration estimates across eastern North America. The resulting UFP concentrations are cross-evaluated with simulations from a global aerosol microphysics model. There is a negative bias in the model output relative to the satellite-driven proxy, which is largest (up to 76%) in summer and may be due to overestimation of UFP from the satellite-based algorithm derived herein, due to the higher availability of remote sensing data in clear-sky conditions or uncertainty in the model simulation of new particle formation. Nevertheless, the model and algorithm indicate similar spatial and seasonal variability (spatial correlation coefficients of 0.10 to 0.56), indicating the value of the satellite-based UFP proxy in global and regional model evaluation exercises and in efforts to identify regions where future in situ data collection should be prioritized.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2012.750773", "year": 2013, "title": "Enhanced SO2 concentrations observed over northern India: role of long-range transport", "abstract": "The combustion of fossil fuels (coal and petroleum products) constitutes a source of continuous release of anthropogenic SO2 into the atmosphere. Furthermore, natural sources such as volcanoes can inject large amounts of SO2 directly into the troposphere and sometimes even into the stratosphere. These event-based volcanic eruptions provide solitary opportunities to study the transport and transformation of atmospheric constituents. In this study, we present an episode of high SO2 concentration over northern India as a result of long-range transport from Africa using multiple satellite observations. Monthly averaged column SO2 values over the Indo-Gangetic Plain (IGP) were observed in the range of 0.60.9 Dobson units (DU) during November 2008 using observations from the Ozone Monitoring Instrument (OMI). These concentrations were conspicuously higher than the background concentrations (<0.3 DU) observed during 20052010 over this region. The columnar SO2 loadings were highest on 6 November over most of the IGP region and even exceeded 6 DU, a factor of 1020 higher than background levels in some places. These enhanced SO2 levels were not reciprocated in satellite-derived NO2 or CO columns, indicating transport from a non-anthropogenic SO2 source. As most of the local aerosols over the IGP region occur below 3 km, a well-separated layer at 45 km was observed from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite. Wind fields and back-trajectory analysis revealed a strong flow originating from the Dalaffilla volcanic eruption in Ethiopia during 46 November 2008. Although volcanic SO2 plumes have been extensively studied over many parts of Asia, Europe, and the USA, analysis of such events for the IGP region is being reported for the first time in this study.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/TC-7-1205-2013", "year": 2013, "title": "Micrometeorological conditions and surface mass and energy fluxes on Lewis Glacier, Mt Kenya, in relation to other tropical glaciers", "abstract": "Abstract. The Lewis Glacier on Mt Kenya is one of the best-studied tropical glaciers, but full understanding of the interaction of the glacier mass balance and its climatic drivers has been hampered by a lack of long-term meteorological data. Here we present 2.5 yr of meteorological data collected from the glacier surface from October 2009 to February 2012. The location of measurements is in the upper portion of Lewis Glacier, but this location experiences negative annual mass balance, and the conditions are comparable to those experienced in the lower ablation zones of South American glaciers in the inner tropics. In the context of other glaciated mountains of equatorial East Africa, the summit zone of Mt Kenya shows strong diurnal cycles of convective cloud development as opposed to the Rwenzoris, where cloud cover persists throughout the diurnal cycle, and Kilimanjaro, where clear skies prevail. Surface energy fluxes were calculated for the meteorological station site using a physical mass- and energy-balance model driven by measured meteorological data and additional input parameters that were determined by Monte Carlo optimization. Sublimation rate was lower than those reported on other tropical glaciers, and melt rate was high throughout the year, with the glacier surface reaching the melting point on an almost daily basis. Surface mass balance is influenced by both solid precipitation and air temperature, with radiation providing the greatest net source of energy to the surface. Cloud cover typically reduces the net radiation balance compared to clear-sky conditions, and thus the frequent formation of convective clouds over the summit of Mt Kenya and the associated higher rate of snow accumulation are important in limiting the rate of mass loss from the glacier surface. The analyses shown here form the basis for future glacier-wide mass and energy balance modeling to determine the climate proxy offered by the glaciers of Mt Kenya.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ACP-11-9839-2011", "year": 2011, "title": "Sulfur dioxide and primary carbonaceous aerosol emissions in China and India, 19962010", "abstract": "Abstract. China and India are the two largest anthropogenic aerosol generating countries in the world. In this study, we develop a new inventory of sulfur dioxide (SO2) and primary carbonaceous aerosol (i.e., black and organic carbon, BC and OC) emissions from these two countries for the period 19962010, using a technology-based methodology. Emissions from major anthropogenic sources and open biomass burning are included, and time-dependent trends in activity rates and emission factors are incorporated in the calculation. Year-specific monthly temporal distributions for major sectors and gridded emissions at a resolution of 0.10.1 distributed by multiple year-by-year spatial proxies are also developed. In China, the interaction between economic development and environmental protection causes large temporal variations in the emission trends. From 1996 to 2000, emissions of all three species showed a decreasing trend (by 9 %17 %) due to a slowdown in economic growth, a decline in coal use in non-power sectors, and the implementation of air pollution control measures. With the economic boom after 2000, emissions from China changed dramatically. BC and OC emissions increased by 46 % and 33 % to 1.85 Tg and 4.03 Tg in 2010. SO2 emissions first increased by 61 % to 34.0 Tg in 2006, and then decreased by 9.2 % to 30.8 Tg in 2010 due to the wide application of flue-gas desulfurization (FGD) equipment in power plants. Driven by the remarkable energy consumption growth and relatively lax emission controls, emissions from India increased by 70 %, 41 %, and 35 % to 8.81 Tg, 1.02 Tg, and 2.74 Tg in 2010 for SO2, BC, and OC, respectively. Monte Carlo simulations are used to quantify the emission uncertainties. The average 95 % confidence intervals (CIs) of SO2, BC, and OC emissions are estimated to be 16 %17 %, 43 %93 %, and 43 %80 % for China, and 15 %16 %, 41 %87 %, and 44 %92 % for India, respectively. Sulfur content, fuel use, and sulfur retention of hard coal and the actual FGD removal efficiency are the main contributors to the uncertainties of SO2 emissions. Biofuel combustion related parameters (i.e., technology divisions, fuel use, and emission factor determinants) are the largest source of OC uncertainties, whereas BC emissions are also sensitive to the parameters of coal combustion in the residential and industrial sectors and the coke-making process. Comparing our results with satellite observations, we find that the trends of estimated emissions in both China and India are in good agreement with the trends of aerosol optical depth (AOD) and SO2 retrievals obtained from different satellites.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-10-6311-2010", "year": 2010, "title": "Sulfur dioxide emissions in China and sulfur trends in East Asia since 2000", "abstract": "Abstract. With the rapid development of the economy, the sulfur dioxide (SO2) emission from China since 2000 is of increasing concern. In this study, we estimate the annual SO2 emission in China after 2000 using a technology-based methodology specifically for China. From 2000 to 2006, total SO2 emission in China increased by 53%, from 21.7 Tg to 33.2 Tg, at an annual growth rate of 7.3%. Emissions from power plants are the main sources of SO2 in China and they increased from 10.6 Tg to 18.6 Tg in the same period. Geographically, emission from north China increased by 85%, whereas that from the south increased by only 28%. The emission growth rate slowed around 2005, and emissions began to decrease after 2006 mainly due to the wide application of flue-gas desulfurization (FGD) devices in power plants in response to a new policy of China's government. This paper shows that the trend of estimated SO2 emission in China is consistent with the trends of SO2 concentration and acid rain pH and frequency in China, as well as with the increasing trends of background SO2 and sulfate concentration in East Asia. A longitudinal gradient in the percentage change of urban SO2 concentration in Japan is found during 20002007, indicating that the decrease of urban SO2 is lower in areas close to the Asian continent. This implies that the transport of increasing SO2 from the Asian continent partially counteracts the local reduction of SO2 emission downwind. The aerosol optical depth (AOD) products of Moderate Resolution Imaging Spectroradiometer (MODIS) are found to be highly correlated with the surface solar radiation (SSR) measurements in East Asia. Using MODIS AOD data as a surrogate of SSR, we found that China and East Asia excluding Japan underwent a continuous dimming after 2000, which is in line with the dramatic increase in SO2 emission in East Asia. The trends of AOD from both satellite retrievals and model over East Asia are also consistent with the trend of SO2 emission in China, especially during the second half of the year, when sulfur contributes the largest fraction of AOD. The arrested growth in SO2 emissions since 2006 is also reflected in the decreasing trends of SO2 and SO42 concentrations, acid rain pH values and frequencies, and AOD over East Asia.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1029/2018JD029049", "year": 2018, "title": "Sources of black carbon deposition to the Himalayan glaciers in current and future climates", "abstract": "The Weather Research and Forecasting model coupled with Chemistry and a modified version of the Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants (ECLIPSE) 5a emission inventory were used to investigate the sources impacting black carbon (BC) deposition to the Himalaya, Karakoram, and Hindu Kush (HKHK) region. This work extends previous studies by simulating deposition to the HKHK region not only under current conditions but also in the 20402050 period under two realistic emission scenarios and in three different phases of the El NinoSouthern Oscillation (ENSO). Under current conditions, sources from outside our South Asian modeling domain have a similar impact on total BC deposition to the HKHK region (3587%, varying with month) as South Asian anthropogenic sources (1362%). Industry (primarily brick kilns) and residential solid fuel burning combined account for 4566% of the in-domain anthropogenic BC deposition to the HKHK region. Under a no further control emission scenario for 20402050, the relative contributions to BC deposition in the HKHK region are more skewed toward in-domain anthropogenic sources (4565%) relative to sources outside the domain (2652%). The in-domain anthropogenic BC deposition has significant contributions from industry (3242%), solid fuel burning (1728%), and diesel fuel burning (1727%). Under a scenario in which emissions in South Asia are mitigated, the relative contribution from South Asian anthropogenic sources is significantly reduced to 1134%. The changes due to phase of ENSO do not seem to follow consistent patterns with ENSO. Future work will use the high-resolution deposition maps developed here to determine the impact of different sources of BC on glacier melt and water availability in the region.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/RS12132100", "year": 2020, "title": "Air pollution scenario over China during COVID-19", "abstract": "The unprecedented slowdown in China during the COVID-19 period of November 2019 to April 2020 should have reduced pollution in smog-laden cities. However, moderate resolution imaging spectrometer (MODIS) satellite retrievals of aerosol optical depth (AOD) show a marked increase in aerosols over the BeijingTianjinHebei (BHT) region and most of Northeast and Central China, compared with the previous winter. Fine particulate (PM2.5) data from ground monitoring stations show an increase of 19.5% in Beijing during January and February 2020, and no reduction for Tianjin. In March and April 2020, a different spatial pattern emerges, with very high AOD levels observed over 50% of the Chinese mainland, and including peripheral regions in the northwest and southwest. At the same time, ozone monitoring instrument (OMI) satellite-derived NO2 concentrations fell drastically across China. The increase in PM2.5 while NO2 decreased in BTH and across China is likely due to enhanced production of secondary particulates. These are formed when reductions in NOx result in increased ozone formation, thus increasing the oxidizing capacity of the atmosphere. Support for this explanation is provided by ground level air quality data showing increased volume of fine mode aerosols throughout February and March 2020, and increased levels of PM2.5, relative humidity (RH), and ozone during haze episodes in the COVID-19 lockdown period. Backward trajectories show the origin of air masses affecting industrial centers of North and East China to be local. Other contributors to increased atmospheric particulates may include inflated industrial production in peripheral regions to compensate loss in the main population and industrial centers, and low wind speeds. Satellite monitoring of the extraordinary atmospheric conditions resulting from the COVID-19 shutdown could enhance understanding of smog formation and attempts to control it.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1155/2018/8746068", "year": 2018, "title": "Analysis of SO2 pollution changes of Beijing-Tianjin-Hebei region over China based on OMI observations from 2006 to 2017", "abstract": "Sulfur dioxide (SO2) in the planetary boundary layer (PBL) as a kind of gaseous pollutant has a strong effect regarding atmospheric environment, air quality, and climate change. As one of the most polluted regions in China, air quality in Beijing-Tianjin-Hebei (BTH) region has attracted more attention. This paper aims to study the characteristics of SO2 distribution and variation over BTH. Spatial and temporal variations for a long term (20062017) over BTH derived from OMI PBL SO2 products were discussed. The temporal trends confirm that the SO2 loading falls from average 0.88 DU to 0.16 DU in the past 12 years. Two ascending fluctuations in 2007 and 2011 appeared to be closely related to the economic stimulus of each five-year plan (FYP). The spatial analysis indicates an imbalanced spatial distribution pattern, with higher SO2 level in the southern BTH and lower in the northern. This is a result of both natural and human factors. Meanwhile, the SO2 concentration demonstrates a decreasing trend with 14.92%, 28.57%, and 27.43% compared with 2006, during the events of 2008 Olympic Games, 2014 Asia-Pacific Economic Cooperation (APEC) summit, and 2015 Military Parade, respectively. The improvement indicates that the direct effect is attributed to a series of long-term and short-term control measures, which have been implemented by the government. The findings of this study are desirable to assist local policy makers in the BTH for drawing up control strategies regarding the mitigation of environmental pollution in the future.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JASTP.2020.105491", "year": 2021, "title": "Impact of aerosols on surface ozone during COVID-19 pandemic in southern India: A multi-instrumental approach from ground and satellite observations, and model simulations", "abstract": "The World Health Organization (WHO) declared the coronavirus disease of 2019 (COVID-19) as a pandemic due to its widespread global infection. This has resulted in lockdown under different phases in many nations, including India, around the globe. In the present study, we report the impact of aerosols on surface ozone in the context of pre-lockdown (01st - 24th March 2020 (PLD)), lockdown phase1 (25th March to 14th April 2020 (LDP1)), and lockdown phase 2 (15th April to 03rd May 2020 (LDP2)) on clear days at a semi-arid site, Anantapur in southern India using both in situ observations and model simulations. Collocated measurements of surface ozone (O3), aerosol optical depth (AOD), black carbon mass concentration (BC), total columnar ozone (TCO), solar radiation (SR), and ultraviolet radiation (UV-A) data were collected using an Ozone analyzer, MICROTOPS sunphotometer, Ozonometer, Aethalometer, and net radiometer during the study period. The diurnal variations of O3 and BC exhibited an opposite trend during three phases. The concentrations of ozone were ~10.7% higher during LDP1 (44.8 5.2 ppbv) than the PLD (40.5 6.0 ppbv), which mainly due to an unprecedented reduction in NOx emissions leading to a lower O3 titration by NO. The prominent increase in the surface zone during LDP1 is reasonably consistent with the observed photolysis frequencies (j (O1D)) through Tropospheric Ultraviolet and Visible (TUV) model. The results show that a pronounced spectral and temporal variability in the AOD during three lockdown phases is mainly due to distinct aerosol sources. The increase in AOD during LDP2 due to long-range transport can bring large amounts of mineral dust and smoke aerosols from the west Asian region and central India, and which is reasonably consistent with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) air mass back trajectories and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts analysis over the measurement location. Overall, a drastic reduction in BC concentration (~8.4%) and AOD (10.8%) were observed in the semi-arid area during LDP1 with correspondence to PLD. The columnar aerosol size distributions retrieved from the spectral AODs followed power-law plus unimodal during three phases. The absorption angstrom exponent (AAE) analysis reveals a predominant contribution to the BC from biomass burning activities during the lockdown period over the measurement location.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.DYNATMOCE.2020.101184", "year": 2021, "title": "Evaluation of the assimilation of conventional and satellite-based observations in simulating heavy rainfall event using WRFDA over the North-West Himalayan region", "abstract": "Present work elucidates the impact of 3DVAR data assimilation technique for the simulation of one of the heavy rainfall events reported over Kotdwara region in the North-West Himalayan (NWH) region on 4th August 2017. We have examined the impact of conventional and satellite-based radiance datasets on the simulated results with and without assimilating the observations into the Weather Research and Forecasting (WRF) model. Three experiments have been designed with 3 nested domains of variable resolutions, one without assimilation (referred as control experiment) and other two experiments after assimilating conventional and satellite radiances observations (refer as DA-OBS and DA-SAT respectively). In the present study, assimilation of surface, upper air and the satellite-based radiance observations has been carried out for the outermost domain with horizontal resolution of 9 km. Statistical analysis suggests that the correlation coefficient is high (0.55) and root mean square error (RMSE) is low (17.12) for DA-SAT experiment as compared to other two experiments. Substantial improvement in the location, pattern and intensity of extreme rainfall event is noted after assimilation of both conventional and satellite observations with respect to the observed rainfall data. However, it is noted that the assimilation of satellite radiances has greater impact in simulating better intensity of the heavy rainfall event as compared to the assimilation of conventional observations. Plausible reason behind this could be the non-availability of the conventional observations close to the extreme rainfall event affected region.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSRES.2020.105341", "year": 2021, "title": "Evaluation of GPM-IMERG and TRMM-3B42 precipitation products over Pakistan", "abstract": "Understanding the performance of remotely-sensed precipitation with rain gauge as reference is essential before their application in estimating multiple processes. In current study, the Global Precipitation Measurements from Integrated Multi-satellite Retrievals (GPM-IMERG) and Tropical Rainfall Measuring Mission (TRMM-3B42) precipitation products were evaluated, taking the rain gauge data as a reference for the period of 2004 to 2018 over Pakistan. The data at daily, monthly, annual and seasonal timescales were evaluated using multiple statistical (three continuous and four categorical) error metrics. The Satellite Precipitation Products (SPPs) showed consistent precipitation climatology with some regional differences. All SPPs overall performed well in the central and southern regions compared to the northern region of study area. Evaluation revealed that the performance of SPPs was influenced by topography, while the error characteristics of SPPs were dependent on the precipitation intensity and climatic condition of the region. The SPPs were able to capture the extreme precipitation events (95th percentile) across different climatic regions. The highest values for probability of detection (POD), critical success index (CSI), and accuracy (ACC) at the rate of 0.7, 0.4, and 0.9 were observed respectively, while the lowest value for false alarm ratio (FAR) is 0.4. The IMERG final run harmonizes rain gauges very closely in plain and medium elevation regions, while root mean square difference greater than 20 mm/month were observed for high altitude. The spatial distribution of correlation coefficients with the values greater than 0.7 suggest that selected SPPs well captured the seasonality and mutual comparison shows that IMERG final run performed well, followed by TRMM-3B42, whereas in winter and pre-monsoon, the IMERG early run and IMERG late run captured higher precipitation values in the northeast of the study area. The results can help the researchers to select reliable SPPs as an alternate source of rain gauge in the country and other adjoining regions and the data evaluation information can help algorithm developers to rectify the errors and improve the selected SPPs.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ENVRES.2020.110665", "year": 2021, "title": "Phase-wise analysis of the COVID-19 lockdown impact on aerosol, radiation and trace gases and associated chemistry in a tropical rural environment", "abstract": "Phase-wise variations in different aerosol (BC, AOD, PM1, PM2.5 and PM10), radiation (direct and diffused) and trace gases (NO, NO2, CO, O3, SO2, CO2 and CH4) and their associated chemistry during the COVID-19 lockdown have been investigated over a tropical rural site Gadanki (13.5 N, 79.2 E), India. Unlike most of the other reported studies on COVID-19 lockdown, this study provides variations over a unique tropical rural environment located at a scientifically strategic location in the Southern Indian peninsula. Striking differences in the time series and diurnal variability have been observed in different phases of the lockdown. The levels of most species that are primarily emitted from anthropogenic activities reduced significantly during the lockdown which also impacted the levels and diurnal variability of secondary species like O3. When compared with the same periods in 2019, short-lived trace gas species such as NO, NO2, SO2 which have direct anthropogenic emission influence have shown the reduction over 50%, whereas species like CO and O3 which have direct as well as indirect impacts of anthropogenic emissions have shown reductions up to 10%. Long-lived species (CO2 and CH4) have shown negligible difference (<1%). BC and AOD have shown reductions over 20%. Particulate Matter (1, 2.5 and 10) reductions have been in the range of 40 to 50% when compared to the pre-lockdown period. The changes in shortwave downward radiation at the surface, diffuse component due to the scattering and diffuse fraction have been +2.2%, 4.1% and 2.4%, respectively, in comparison with 2019. In contrast with the studies over urban environments, air quality category over the rural environment remained same during the lockdown despite reduction in pollutants level. All the variations observed for different species and their associated chemistry provides an excellent demonstration of rural atmospheric chemistry and its intrinsic links with the precursor concentrations and dynamics.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.26491/MHWM/133088", "year": 2021, "title": "Assessment of the GPM IMERG and CHIRPS precipitation estimations for the steppe part of the Crimea", "abstract": "This paper compares the spatial distribution datasets on monthly precipitation totals derived from the Famine Early Warning System Network FEWS NET service (CHIRPS 2.0 product) and the International Mission of the Global Pre-cipitation Measurement GPM (IMERG v06 product) with ground-based...", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1038/S41598-020-76936-Z", "year": 2020, "title": "Aerosol-induced atmospheric heating rate decreases over South and East Asia as a result of changing content and composition", "abstract": "Aerosol emissions from human activities are extensive and changing rapidly over Asia. Model simulations and satellite observations indicate a dipole pattern in aerosol emissions and loading between South Asia and East Asia, two of the most heavily polluted regions of the world. We examine the previously unexplored diverging trends in the existing dipole pattern of aerosols between East and South Asia using the high quality, two-decade long ground-based time series of observations of aerosol properties from the Aerosol Robotic Network (AERONET), from satellites (Moderate Resolution Imaging Spectroradiometer (MODIS) and Ozone Monitoring Instrument (OMI)), and from model simulations (Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). The data cover the period since 2001 for Kanpur (South Asia) and Beijing (East Asia), two locations taken as being broadly representative of the respective regions. Since 2010 a dipole in aerosol optical depth (AOD) is maintained, but the trend is reversedthe decrease in AOD over Beijing (East Asia) is rapid since 2010, being 17% less in current decade compared to first decade of twenty-first century, while the AOD over South Asia increased by 12% during the same period. Furthermore, we find that the aerosol composition is also changing over time. The single scattering albedo (SSA), a measure of aerosols absorption capacity and related to aerosol composition, is slightly higher over Beijing than Kanpur, and has increased from 0.91 in 2002 to 0.93 in 2017 over Beijing and from 0.89 to 0.92 during the same period over Kanpur, confirming that aerosols in this region have on an average become more scattering in nature. These changes have led to a notable decrease in aerosol-induced atmospheric heating rate (HR) over both regions between the two decades, decreasing considerably more over East Asia ( 31%) than over South Asia ( 9%). The annual mean HR is lower now, it is still large ( 0.6 K per day), which has significant climate implications. The seasonal trends in AOD, SSA and HR are more pronounced than their respective annual trends over both regions. The seasonal trends are caused mainly by the increase/decrease in anthropogenic aerosol emissions (sulfate, black carbon and organic carbon) while the natural aerosols (dust and sea salt) did not change significantly over South and East Asia during the last two decades. The MERRA-2 model is able to simulate the observed trends in AODs well but not the magnitude, while it also did not simulate the SSA values or trends well. These robust findings based on observations of key aerosol parameters and previously unrecognized diverging trends over South and East Asia need to be accounted for in current state-of-the-art climate models to ensure accurate quantification of the complex and evolving impact of aerosols on the regional climate over Asia.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS11060570", "year": 2020, "title": "Spatial-Temporal Pattern of Black Carbon (BC) Emission from Biomass Burning and Anthropogenic Sources in New South Wales and the Greater Metropolitan Region of Sydney, Australia", "abstract": ": Biomass burnings either due to Hazards Reduction Burnings (HRBs) in late autumn and early winter or bushfires during summer periods in various part of the world (e.g., CA, USA or New South Wales, Australia) emit large amount of gaseous pollutants and aerosols. The emissions, under favourable meteorological conditions, can cause elevated atmospheric particulate concentrations in metropolitan areas and beyond. One of the pollutants of concern is black carbon (BC), which is a component of aerosol particles. BC is harmful to health and acts as a radiative forcing agent in increasing the global warming due to its light absorption properties. Remote sensing data from satellites have becoming increasingly available for research, and these provide rich datasets available on global and local scale as well as in situ aethalometer measurements allow researchers to study the emission and dispersion pattern of BC from anthropogenic and natural sources. The Department of Planning, Industry and Environment (DPIE) in New South Wales (NSW) has installed recently from 2014 to 2019 a total of nine aethalometers to measure BC in its state-wide air quality network to determine the source contribution of BC and PM2.5 (particulate Matter less than 2.5 m in diameter) in ambient air from biomass burning and anthropogenic combustion sources. This study analysed the characteristics of spatial and temporal patterns of black carbon (BC) in New South Wales and in the Greater Metropolitan Region (GMR) of Sydney, Australia, by using these data sources as well as the trajectory HYSPLIT (Hybrid Single Particle Lagrangian Integrated Trajectory) modelling tool to determine the source of high BC concentration detected at these sites. The emission characteristics of BC in relation to PM2.5 is dependent on the emission source and is analysed using regression analysis of BC with PM2.5 time series at the receptor site for winter and summer periods. The results show that, during the winter, correlation between BC and PM2.5 is found at nearly all sites while little or no correlation is detected during the summer period. Traffic vehicle emission is the main BC emission source identified in the urban areas but was less so in the regional sites where biomass burnings/wood heating is the dominant source in winter. The BC diurnal patterns at all sites were strongly influenced by meteorology.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S12517-021-07591-5", "year": 2021, "title": "Time-lag correlations between atmospheric anomalies and earthquake events in Iran and the surrounding Middle East region (19802018)", "abstract": "The main goal of this study was to survey a possible correlation between atmospheric parameters (air temperature, precipitation rate) and subsequent earthquakes in Iran and the surrounding Middle Eastern region. This research was carried out in response to previous work regarding atmospheric anomalies prior to major earthquake events. Area-averaged daily and monthly time-series data were compiled from global reanalyzed datasets for the study area between 1980 and 2018. The time-lagged correlation test through the cross-correlation function was examined to distinguish possible relationships between earthquake events and climatic elements within daily and monthly shifts. The results revealed that the precipitation has a strong ability to predict the earthquake series at least from 312 months prior to the earthquakes. The estimated lagged correlation confirms a positive relationship between precipitation and subsequent earthquake events within 3 to 103 days lag-time (CCF= 0.036 to 0.046). Contrarily, no precursory relation was found between atmospheric temperature variations and subsequent earthquake events in Iran and the surrounding region.", "labels": [ { "id": 5, "name": "Earthquakes" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/978-3-030-66238-7_20", "year": 2021, "title": "Northern Gulf Marine Biodiversity in Relevance to the River Discharge", "abstract": "This chapter summarizes the results of research studies, which addressed the peculiarity of the estuarine and northern Arabian Gulf marine environment and the influence of the Shatt Al-Arab River and its associated marshes on the oceanography and biodiversity of the northern Gulf. The findings of the studies indicated that the northern waters of Kuwait, which are impacted by the Shatt Al-Arab River discharge, displayed lower salinity, higher nitrate concentration, higher chlorophyll-a, and higher sedimentation. The biodiversity of the northern waters of the Gulf also was significantly distinguished from the adjacent area away from the influence of the river flow. Discharge of the Shatt Al-Arab is considered to be a dominating driver of the northern Gulfs ecology and largely responsible for the primary and secondary productivity of Kuwaits waters. Long-term reduction in river discharge due to man-made alterations (damming and diversion of rivers) impacted the oceanographic characteristics of Kuwaits waters with implication to fisheries resources. Management of Shatt Al-Arab River discharge into the Gulf requires cooperation among the riparian countries and downstream countries like Kuwait to preserve the productivity, biodiversity, and uniqueness of the northern Gulf ecosystems. Long-term monitoring and assessment as well as joint research programs involving scientists from the three concerned countries, Kuwait, Iraq, and Iran, are needed.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SOLENER.2022.01.066", "year": 2022, "title": "Evaluation of MERRA-2 hourly surface solar radiation across China", "abstract": "Accurate global horizontal irradiance (GHI) is key to solar energy resource assessment and prediction. The GHI provided by MERRA-2 (Version 2 of the Modern-Era Retrospective Analysis for Research and Applications) still needs to be evaluated over China. In this study, GHI observed by 37 ground stations in 2018 are used to systematically assess the MERRA-2 GHI performance for all-sky, clear-sky and cloudy days. Moreover, aerosol and cloud products from MERRA-2 are compared with satellite counterparts to determine the dominant factor affecting MERRA-2 GHI. The results show that MERRA-2 overestimates the hourly and daily mean GHI by 69.35 W/m2 and 27.54 W/m2 on all-sky days, respectively. The mean bias error and root mean square error of hourly GHI between MERRA-2 and CERN are 4.98 W/m2 and 124.85 W/m2 on clear-sky days and 107.16 W/m2 and 215.24 W/m2 on cloudy days, respectively. These values indicate a much greater overestimation of MERRA-2 GHI on cloudy days than on clear-sky days. By comparing cloud fraction (CF) and aerosol optical thickness (AOD) between the Moderate-resolution Imaging Spectroradiometer (MODIS) and MERRA-2, we find that the overestimation of MERRA-2 GHI in most areas is induced by the substantial underestimation of MERRA-2 CF. MERRA-2 underestimates AOD in North China and further enhances the overestimation of GHI caused by the underestimation of MERRA-2 CF, whereas the overestimation of AOD in the Sichuan Basin and Southeastern China partly counterbalances the overestimation of GHI caused by the underestimation of MERRA-2 CF.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.3390/ATMOS13020305", "year": 2022, "title": "Projection of the Near-Future PM2.5 in Northern Peninsular Southeast Asia under RCP8.5", "abstract": "Throughout the year, particularly during the dry season, the northern peninsula of Southeast Asia struggles with air pollution from PM2.5. In this study, we used the Nested Regional Climate and Chemistry Model (NRCM-Chem) to predict the PM2.5 concentrations over Southeast Asias northern peninsula during the years 20202029 under the Representative Concentration Pathway (RCP)8.5. In general, the model reasonably shows a good result, including temperature, precipitation, and PM2.5 concentration, compared to the observation with an Index of Agreement (IOA) in the range of 0.63 to 0.80. However, there were some underestimations for modeled precipitation and temperature and an overestimation for modeled PM2.5 concentration. As a response to changes in climatic parameters and the emission of PM2.5s precursors, PM2.5 concentrations tend to increase across the region in the range of (+1) to (+35) g/m3 during the dry season (November to April) and decline in the range of (3) to (30) g/m3 during the wet season (May to October). The maximum increase in PM2.5 concentrations were found in March by >40 g/m3.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2011.07.016", "year": 2012, "title": "Biomass burning aerosols observed in Eastern Finland during the Russian wildfires in summer 2010 Part 2: Remote sensing", "abstract": "In the summer 2010 extensive wildfires in the western parts of Russia emitted massive amounts of smoke and aerosols into the atmosphere. These smoke plumes also drifted to Finland over 1000 km away from the fires. The smoke plumes were detected in Kuopio (Eastern Finland) with a wide range of instruments on two specific days: July 29 and August 8. The plumes were studied with several spaceborne instruments: MODIS, OMI, AIRS and CALIOP. Furthermore, a ground-based remote sensing instrument (Cimel) was also used in the analysis. Our results show that ground-based and spaceborne instruments were in good agreement on the Aerosol optical depth (AOD550) values during the episode (Julymid August). The correlation coefficient between MODIS and AERONET measurements done in Kuopio was 0.98 and the mean difference was 0.005 (AERONET AOD being larger). Spaceborne measurements of carbon monoxide provided a clear indicator for biomass burning aerosols. Particle mass (PM2.5) and AERONET AOD550 measurements were also in good agreement with a correlation coefficient of 0.87. Single scattering albedo (SSA675) values derived from AERONET measurements and calculated from in-situ absorption and scattering measurements had similar values close 0.9. On average, the daily in-situ SSA values were 0.02 smaller than the corresponding AERONET values. CALIOP provided vertical profiles of the smoke plumes for the two most polluted days in Kuopio. In July the plume was located close to the surface (mainly below 2 km) while in August the plume had two elevated layers: one between 1 and 2 km and the other between 2.5 and 4 km.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105820", "year": 2021, "title": "Incorporating gridded concentration data in air pollution back trajectories analysis for source identification", "abstract": "The identification of air pollution sources is a challenging task due to the confounding effects of local and transboundary emitters. While the Potential Source Contribution Function (PSCF) is a useful tool for trajectory analysis and source identification, it can overestimate the impact of less polluted areas in which a trajectory event passed through. In this work, we propose incorporating air pollutant concentration fields from reanalysis data to improve the PSCF method's performance that avoids the overcontribution of less polluted areas. We develop the 3D-PSCF-CONC based on an updated three-dimensional version of the PSCF method (3D-PSCF). We used as a test case the Metropolitan Area of Sao Paulo (MASP) in Brazil, one of the most polluted regions in the world, for comparing the results of the conventional and the new PSCF method. A monitoring station in Vitoria - Espirito Santo, Brazil which has smaller local emissions than MASP was used as an auxiliary test case. Hourly carbon monoxide (CO) and sulfur dioxide (SO2) concentrations from 2015 to 2019 of monitoring stations were analyzed. The daily average concentrations of CO and SO2 were used as a threshold on the probability calculations. An overall of 1825 backward trajectories from HYSPLIT version 4 was processed using the three models. CO and SO2 surface concentrations from MERRA-2, with a resolution of 0.5 x 0.625 was incorporated in the 3D-PSCF-CONC to correct the potential contribution calculation based on the air pollutant concentration field. Our results revealed that the 3D-PSCF-CONC reached a more consistent identification of local and regional sources, rather than emphasizing mostly the regional sources as the other PSCF methods. The 3D-PSCF-CONC reduced the potential contribution of less polluted and high precipitation areas. The analysis suggests a contribution of vehicular sources close to the receptor site in MASP and long-range transport of industrial emissions and biomass burning from the land clearing of sugarcane production. This work presents an important tool for understanding the air pollution process and source identification.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSENV.2014.02.059", "year": 2014, "title": "Signature of tropospheric ozone and nitrogen dioxide from space: A case study for Athens, Greece", "abstract": "The aim of the present study is to investigate the variability of the tropospheric ozone and nitrogen dioxide (NO2) columns over mainland Greece, by using observations carried out by satellite-borne instrumentation and Multi Sensor Reanalysis. The results obtained show that the tropospheric ozone residual (TOR) dispersed farther away than the tropospheric NO2 column (TNO), due to the longer TOR's lifetime in respect to that of TNO. This results in the influence of the air quality of the nearby southern islands from the air pollution of the greater Athens basin. Furthermore, the TOR and TNO columns over Athens, for the period October 2004 to December 2011 were found to be negatively correlated with a correlation coefficient 0.85, in contrast to recent findings which suggested strong positive correlation. Interestingly, this strong negative correlation into a slight positive correlation when the TNO concentration becomes higher than around 4 1015 molec cm2, thus being best fitted by a quadratic relationship. In addition, the temporal evolution of TOR during 19791993 showed a decline of 0.2% per decade and just after 1993 it seems to obey a positive trend of 0.1% per decade, thus recovering during the period 19932011 almost 63% of the lost TOR amounts through the years 19791993. Finally, the association between TOR, the total ozone column (TOZ), the tropopause height and the outgoing longwave radiation (OLR) is presented by analysing observations during 19792011. An unexpected positive correlation between OLR and TOR was found, which may probably be attributed to the fact that enhanced abundance in tropospheric water vapor reduces the summertime TOR maximum by destructing ozone in the lower and middle troposphere through uptake mechanisms, thus emitting higher amounts of longwave radiation upwards.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1175/MWR-D-14-00184.1", "year": 2015, "title": "Two Heavy Rainfall Types over the Korean Peninsula in the Humid East Asian Summer Environment: A Satellite Observation Study", "abstract": "A total of 10 years (200211) of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) reflectivities, signaling heavy rainfall (>10 mm h1), were objectively classified by applying the K-means clustering method in order to obtain typical reflectivity profiles associated with heavy rainfall over East Asia. Two types of heavy rainfall emerged as the most important rain processes over East Asia: type 1 (cold type) characterized by high storm height and abundant ice water under convectively unstable conditions, developing mostly over inland China; and type 2 (warm type) associated with a lower storm height and lower ice water content, developing mostly over the ocean. These two types also show sharp contrasts in relation to their seasonal changes and in the diurnal variation of frequency maxima, in addition to other contrasting meteorological parameters. The PR-derived heavy rain events were observed over the Korean peninsula and their spatiotemporal evolution was examined using 10-yr composites of 11-m brightness temperature from geostationary satellites and Interim ECMWF Re-Analysis (ERA-Interim) data. Cold-type heavy rainfall over Korea is characterized by an eastward moving cloud system with an oval shape while the warm type shows a comparatively wide spatial distribution over an area extending from the southwest to northeast. Overall the warm-type process appears to link the low-level moisture convergence area to the vertically aligned divergence area formed over the jet stream level. This setup continuously pushes air upward under moist-adiabatically near-neutral conditions and thus yields heavy rainfall. As warm-type heavy rainfall persists longer, it is considered to be more responsible for flood events occurring over the Korean peninsula.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105729", "year": 2021, "title": "Reduction of surface radiative forcing observed from remote sensing data during global COVID-19 lockdown", "abstract": "The calamity of the COVID-19 pandemic during the early half of 2020 not only caused a huge physical and economic loss but altered the social behavior of the whole world. The social and economic stagnation imposed in many countries and served as a major cause of perturbation in atmospheric composition. This paper utilized the relation between atmospheric composition and surface radiation and analyzed the impact of global COVID-19 lockdown on land surface solar and thermal radiation. Top of atmosphere (TOA) and surface radiation are obtained from the Clouds and Earth's Radiant Energy System (CERES) and European Reanalysis product (ERA5) reanalysis product. Aerosol Optical Depth (AOD) is obtained from Moderate Resolution Imaging Spectroradiometer (MODIS) while Nitrogen dioxide (NO2), and sulfur dioxide (SO2) are obtained from Ozone Monitoring Instrument (OMI). Observations of all mentioned parameters are studied for the global lockdown period of 2020 (from January to July) and compared with the corresponding months of the previous four years (201619) observations. Regarding surface radiation, April 2020 is the most affected month during the pandemic in which 0.2% increased net solar radiation (NSR), while 3.45% and 4.8% decreased net thermal radiation (NTR) and net radiation (NR) respectively was observed. Average radiative forcing during MarchMay 2020 was observed as 1.09 Wm2, 2.19 Wm2 and 1.09 Wm2 for NSR, NTR and NR, respectively. AOD was reduced by 0.2% in May 2020 while NO2 and SO2 were reduced by 5.4% and 8.8%, respectively, in April 2020. It was observed that NO2 kept on reducing since January 2020 while SO2 kept on reducing since February 2020 which were the pre-lockdown months. These results suggest that a more sophisticated analysis is needed to explain the atmosphere-radiation relation.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2022JD036457", "year": 2022, "title": "An Analysis of the Aerosol Lifecycle Over India: COALESCE Intercomparison of Three General Circulation Models", "abstract": "Atmospheric aerosols or atmospheric particulate matter affects climate variables like temperature and rainfall, agricultural productivity, soil, and human health. We evaluated aerosol lifecycle over India via simulations (20052014) from three general circulation models under the COALESCE project (carbonaceous aerosol emissions, source apportionment, and climate impacts; Venkataraman et al., 2020, 10.1175/bams-d-19-0030.1). The ECHAM6.3-HAM2.3, CAM5.3, and NICAM-SPRINTARS simulations use identical regional emissions (from the Speciated Multi-pollutant generator, SMoG-India-v1). Satisfactory model simulations of meteorological variable magnitudes and seasonal cycle have been achieved partly from the adoption of nudging. Estimations of anthropogenic aerosol, aerosol optical depth (AOD), and particulate matter surface concentrations are significantly improved from (a) dust tuning (b) use of satellite-derived organic aerosol to carbon ratio, and (c) nudged meteorology to capture variables influencing the production of secondary sulfate. Larger wintertime under prediction (30% to 60%) results from over prediction of seasonal planetary boundary layer height and the absence of secondary ammonium nitrate and organic aerosols. Vertical dispersion to higher altitudes than in observations calls for improved modeling of vertical mass flux representation. Carbonaceous aerosol residence time and AOD fraction larger than global mean values in India, with a seasonal predominance in the autumn and winter seasons can be explained by enhanced regional emissions from residential biofuel cooking, agricultural stubble burning, and traditional informal industries like brick production.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41598-020-80026-5", "year": 2021, "title": "Evaluation of the TRMM product for monitoring drought over Paraiba State, northeastern Brazil: a trend analysis", "abstract": "Droughts are complex natural phenomena that influence society's development in different aspects; therefore, monitoring their behavior and future trends is a useful task to assist the management of natural resources. In addition, the use of satellite-estimated rainfall data emerges as a promising tool to monitor these phenomena in large spatial domains. The Tropical Rainfall Measuring Mission (TRMM) products have been validated in several studies and stand out among the available products. Therefore, this work seeks to evaluate TRMM-estimated rainfall data's performance for monitoring the behavior and spatiotemporal trends of meteorological droughts over Paraiba State, based on the standardized precipitation index (SPI) from 1998 to 2017. Then, 78 rain gauge-measured and 187 TRMM-estimated rainfall time series were used, and trends of drought behavior, duration, and severity at eight time scales were evaluated using the MannKendall and Sen tests. The results show that the TRMM-estimated rainfall data accurately captured the pattern of recent extreme rainfall events that occurred over Paraiba State. Drought events tend to be drier, longer-lasting, and more severe in most of the state. The greatest inconsistencies between the results obtained from rain gauge-measured and TRMM-estimated rainfall data are concentrated in the area closest to the coast. Furthermore, long-term drought trends are more pronounced than short-term drought, and the TRMM-estimated rainfall data correctly identified this pattern. Thus, TRMM-estimated rainfall data are a valuable source of data for identifying drought behavior and trends over much of the region.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.ATMOSENV.2021.118923", "year": 2022, "title": "Influence of major typhoons on ocean, atmosphere and air quality of Northwest Pacific during August 2020", "abstract": "Tropical storms (TSs)/Typhoons (TYs) in the Northwest Pacific (NWP) region are one of the most devastating natural hazards, which cause large-scale impacts on human life and infrastructure. In August 2020, a total of 9 tropical storms were identified by International Best Track Archive for Climate Stewardship (IBTrACS) in the NWP region. These TSs/TYs made their landfall over the coastal parts of China, North Korea, and South Korea, while none of them made their landfall over Taiwan. These conditions were unique in recent years and induced drought conditions in Taiwan during 2020. We have carried out a three-dimensional analysis of oceanic, atmospheric, and meteorological parameters for the evaluation of changes associated with typhoons during August 2020. The model, satellite, and ground observations data have been used for the assessment of the impact of these TS/TYs on the ocean, atmosphere, and air quality. The rise in ocean temperature (1 C2 C) was observed even at the depth of 100 m. Strong upwelling of the ocean water in the NWP originated a change in the mixed layer depth and also has affected the salinity in South China, East China, and the Philippines Sea. The strong convective forces during the storm conditions produced a prominent rise in CO and Ozone concentration. These typhoons also affected the air quality of Taiwan during August 2020. The transboundary air pollutants triggered the enhancement in particulate matter (PM1.0 and PM2.5) and surface ozone over Taiwan, which resulted in major health hazards to a large population.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/HYP.14547", "year": 2022, "title": "Stable isotopic variations (D and 18O) in a mountainous river with rapidly changing altitude: Insight into the hydrological processes and rainout in the basin", "abstract": "Hydrological processes play an important role in stable isotopic compositional variations of the river water. The present study includes spatial distributions of stable hydrogen and oxygen isotopes (D and 18O) of a Himalayan River (the Teesta) to trace various hydrological processes and their associated roles on isotopic fractionation of river water. The 18O compositions of the water samples varies between 12.2 and 5.4 (mean: 8.01 1.81) and that of D between 95.1 and 38.5 (mean: 57.6 15.6). The observed compositional variation in 18O, D and d values of river water is mainly governed through snowmelt input, evaporation, and recycled moisture contribution. The variation of 18O and D values point towards an early melting of snow in the basin and a significant contribution of snowmelt to the river water. The orographic induced precipitation front appears to control the hydrological regimes in a distinct manner as reflected in the trend between d values and elevation. The rain shadow affected northern reaches of the basin are characterized with dry & arid climate triggering evaporation whereas, the windward southern side witness temperature influenced evaporation. The study suggests that the differential degree of recycled moisture contribution to the local precipitation is also a key component in bringing the stable isotopic variation in the river water. This varied magnitude of moisture recycling could result from uneven distribution of evapotranspiration and surface water evaporation. Results found that a rapid change in the altitude of a river basin can give rise to different hydrometeorological conditions, thereby resulting in simultaneous operation of almost all the major hydrological processes and a complex isotopic compositional variation in the river water. Also, the rainout percentage in the Teesta basin is found to be higher owing to this rapid rate of elevation increase.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/TROPICALMED8020077", "year": 2023, "title": "Aedes aegypti in Southern Brazil: Spatiotemporal Distribution Dynamics and Association with Climate and Environmental Factors", "abstract": "In Brazil, the mosquito Aedes (Stegomyia) aegypti is considered the main vector of the dengue, chikungunya, and Zika arbovirus transmission. Recent epidemiological studies in southern Brazil have shown an increase in the incidence of dengue, raising concerns over epidemiological control, monitoring, and surveys. Therefore, this study aimed at performing a historical spatiotemporal analysis of the Ae. aegypti house indices (HI) in southern Brazil over the last 19 years. As vector infestation was associated with climatic and environmental variables, HI data from the Brazilian Ministry of Health, climate data from the Giovanni web-based application, and environmental data from the Mapbiomas project were used in this study. Our results showed an expressive increase in the number of HI surveys in the municipalities confirming the vector presence, as compared to those in 2017. Environmental variables, such as urban infrastructure, precipitation, temperature, and humidity, were positively correlated with the Ae. aegypti HI. This was the first study to analyze Ae. aegypti HI surveys in municipalities of southern Brazil, and our findings could help in developing and planning disease control strategies to improve public health.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ANBEHAV.2022.01.002", "year": 2022, "title": "Fitness effects of seasonal birth timing in a long-lived social primate living in the equatorial forest", "abstract": "Reproductive seasonality is the norm in mammals from temperate regions but less common at lower latitudes, where a broad diversity of reproductive phenology strategies is observed. Our knowledge of the evolutionary determinants shaping this diversity remains fragmentary and may reflect high phenotypic plasticity in individual strategies. Here we investigated the ecological determinants and fitness consequences of variation in birth timing across the annual cycle in a social primate endemic to the Congo basin, the mandrill, Mandrillus sphinx, which breeds seasonally. We further examined traits that modulate this variation within and across individuals. We used 9 years of ecological, life history and behavioural data from a natural population to characterize patterns of environmental and reproductive seasonality. We then investigated the consequences of variation in birth timing for pre- and postnatal offspring survival and maternal interbirth intervals. Finally, we studied the influence of within- (reproductive history and age) and between-individual (social rank) traits on variation in birth timing. We found that mandrills daily foraging time varied seasonally, with greater fluctuations for subordinate than dominant females. Birth timing was plastic, as females gave birth year round without detectable consequences for postnatal offspring survival. Giving birth within the birth peak, however, decreased interbirth intervals and probability of miscarriage. Finally, reproductive history and social rank mediated within- and between-individual variation in birth timing, respectively. Specifically, females that experienced a previous reproductive failure gave birth early in the next birthing season and dominant females bred less seasonally than subordinates, which may reflect their more even access to resources across the year. Overall, the selective pressures shaping mandrill reproductive seasonality differed from a classical scenario of seasonal fluctuations in resources limiting offspring survival. A complex interplay between social and ecological factors may thus determine within- and between-individual variation in phenology strategies of tropical and gregarious mammals.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/ATMOS13081264", "year": 2022, "title": "Assessment of Drought Severity and Their Spatio-Temporal Variations in the Hyper Arid Regions of Kingdom of Saudi Arabia: A Case Study from Al-Lith and Khafji Watersheds", "abstract": "The goal of this study is to calculate meteorological drought using the Standard Precipitation Index (SPI) and Standard Precipitation Evapotranspiration Index (SPEI) for the Al-Lith and Khafji basins of the Kingdom of Saudi Arabia (KSA) from 2001 to 2020. The in situ (rain gauges, RGs) and Integrated Multi-satellite Retrievals for GPM (IMERG) data are used in the current study. The meteorological drought is monitored across the AL-Lith and Khafji watersheds. The climate of the Khafji watershed is like the climate of Al-Lith to some extent. Still, due to complex terrain, Al-Lith receives relatively high precipitation and has a higher average temperature than the Khafji watershed. Results show that the total drought periods observed are 166 and 139 months based on SPEI and SPI on a multiple time scale (1, 3, 6, and 12 months) in the Al-Lith watershed, respectively. While, based on SPEI and SPI, the Khafji watershed experienced a drought of 129 and 72 months, respectively. This finding indicates that the SPEI-calculated drought is more severe and persistent in both watersheds than the SPI-calculated drought. Additionally, the correlation coefficient (CC) between SPI and SPEI is investigated; a very low correlation is observed at a smaller scale. CC values of 0.86 and 0.93 for Al-Lith and 0.61 and 0.79 for the Khafji watershed are observed between SPEI-1/SPI-1 and SPEI-3/SPI-3. However, the correlation is significant at high temporal scales, i.e., 6 and 12 months, with CC values of 0.95 and 0.98 for Al-Lith and 0.86 to 0.94 for the Khafji watershed. Overall, the study compared the performance of IMERG with RGs to monitor meteorological drought, and IMERG performed well across both watersheds during the study period. Therefore, the current study recommends the application of IMERG for drought monitoring across data-scarce regions of KSA. Furthermore, SPEI estimates a more severe and long-lasting drought than SPI because of the temperature factor it considers.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1088/2515-7620/AC0BD1", "year": 2021, "title": "Quantifying vegetation response to environmental changes on the Galapagos Islands, Ecuador using the Normalized Difference Vegetation Index (NDVI)", "abstract": "The vegetation of the Galapagos Islands (Ecuador) is strongly influenced by climate. El Nino events, seasonality, isolation, volcanism, and increasing human activity define the ecosystems of the archipelago. Given their socio-cultural and economic importance, it is critical to monitor the response of Galapagos vegetation to changes in climate and assess its vulnerability. This study explores the potential to use Normalized Difference Vegetation Index (NDVI) as a proxy to describe trends in primary productivity in the Galapagos (20002019) and models the relationship between NDVI and climate variables including evaporation and atmospheric carbon dioxide concentration. From numerous possible co-variates compiled from reanalysis and satellites, we identify the independent variables that most strongly influence NDVI using the least absolute shrinkage and selection operator (LASSO) method. Significant variables, including carbon dioxide concentration, evaporation, and autocorrelation (1-month and 12-months lagged NDVI) are then used to model NDVI in a generalized linear model (GLM) framework. The model predicts NDVI more effectively where values for NDVI are high (high elevation, lush vegetation), and clearly reflects seasonality. Validation of the model across pixels produces R 2 values ranging from 0.05 to 0.94, and the mean R 2 is 0.57 (0.65 for elevation >20 m). This methodology has the potential to continuously and non-intrusively monitor vegetation changes in sensitive ecological regions, such as the Galapagos.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ENVC.2022.100624", "year": 2022, "title": "ARIMA and SPSS statistics based assessment of landslide occurrence in western Himalayas", "abstract": "The Jammu-Srinagar National Highway is the critical road connection between Kashmir valley and the rest of India. It passes through extremely steep slopes and high mountains prone to mass movements, particularly landslides and rockslides. Most mountainous roads are constructed on fragile and rocky slopes, and any natural (e.g., precipitation) or human-triggered disturbance (e.g., heavy traffic) can cause a fatal and devastating landslide under the influence of gravity. Many landslide-prone sites along the Highway are responsible for the continuous blockade almost throughout the year but peaking particularly during winters. As a result, it has a high toll on the state's economy and is responsible for many human casualties yearly. The present study aims to characterize various factors and their threshold values responsible for triggering a landslide. Through extensive field surveys, we evaluated different geotechnical parameters of soils at the most landslide-prone site along the Highway and augmented it with the satellite remote sensing datasets to determine the threshold values that trigger a landslide and assess the probability of occurrence of landslide events in the future using Autoregressive Moving Average (ARIMA) model and IBM SPSS Forecasting Model. This work shall help devise countermeasures for managing the landslides in the study area locally and shall serve as the guiding framework for using artificial intelligence and machine learning techniques for hazard management in the Himalayas.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12647-022-00533-W", "year": 2022, "title": "Classification of Different Sky Conditions Based on Solar Radiation Extinction and the Variability of Aerosol Optical Depth, Angstrom Exponent, Fine Particles Over Tehri Garhwal, Uttarakhand, India", "abstract": "On entering the Earths atmosphere, a large amount of solar radiation gets absorbed and scattered by aerosols, clouds, atmospheric gases, and Earths surface. In this context, we discuss an approach to characterize the sky conditions using ground-based observations of solar radiation. The proposed approach is applied to the measured solar radiation for the duration 16 October 2018 to 31 December 2019, at Himalayan Clouds Observatory (HCO), which is situated at Swami Ram Tirtha (SRT) Campus (3034 N, 7841 E) Badshahithaul, Tehri Garhwal, Uttarakhand, India. The present work demonstrates the variation in Clearness Index (KT) associated with Global Horizontal Radiation (Ha), Extraterrestrial Horizontal Radiation (Ho) and associated variability of Aerosol Optical Depth (AOD), Angstrom Exponent (AE) and fine particles (PM2.5 (g m3)) in different sky conditions. Most of the period of 2018 shows clear sky (81.82%) as compared to partially cloudy (4.29%) and cloudy (3.9%) days. Whereas only 20.89% days having clear sky, 38.38% as partially cloudy sky and 34.73% as cloudy sky conditions were observed during 2019. From the variance of Ha and KT, we obtained minimum values in the monsoon and winter from which we get cloudier condition in these seasons. AOD and PM2.5 remains lower in clear sky condition and highest in cloudy condition due to several atmospheric factors. Also, the AE of cloudy cases is marginally lower, implying larger particles, most likely due to swelling in humid conditions. Finally, we observed that the negative correlation between AOD and AE which indicates the swelling particles nearby cloudy region. Similarly, a positive correlation between AOD and PM2.5 indicates the sources of air pollution can influence aerosol loading for all sky conditions.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.EJRS.2022.01.006", "year": 2022, "title": "Remote sensing of vegetation prolonged drought at the salt playas of Hail Saudi Arabia", "abstract": "Drought is a complex natural phenomenon with a wide variety of natural and socioeconomic impacts, including water scarcity, health, agriculture, etc. This study provides a short-term (20002019) trend assessment of drought in Hail region, Saudi Arabia, using the Normalized Difference Vegetation Index (NDVI) and rainfall dataset synchronized by the assessment of the decadal trends of the local land surface temperatures (LST). The NDVI and LST data were obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument, while rainfall data were acquired from the Tropical Rainfal Measuring Mission (TRMM) precipitation database. The impacts of drought on soils and natural vegetation of the region were also considered. Results evidenced that natural vegetation witnessed a prolonged decline between 2000 and 2019, accompanied by a regional increase of the decadal LST trends and decline of rainfall. However, it seems that vegetation communities in this hyper-arid region are of high tolerance to soil salinity and drought. There is a general consensus that drought conditions prevailing in this region reflect the context of climate change prevailing in the region and worldwide.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12648-022-02375-3", "year": 2022, "title": "Variability of air quality and aerosol over Indian region during 20032012", "abstract": "The Indo-Gangetic basin is one of the biggest, most populated and polluted regions in the world. Satellite- and ground-based data show strong seasonal variability of aerosol loading with a maximum during pre-monsoon (summer) season. In this study, decadal (20032012) variability of aerosol optical depth (AOD) derived from AERONET measurements over Kanpur is presented which indicates maximum AOD during 2003 and minimum during 2012. The aerosol size distribution (ASD) exhibits an increase in the radius and a decrease in the width of distribution. It shows an enhancement during 2003 and 2010 and diminished values during 2004, 2007, 2009 and 2011. The ASD is found to show a peak during summer season (pre-monsoon) throughout 20032012 only except the years 2008 and 2011. Moreover, for years 2008 and 2011 ASD showed a peak value during a monsoon month (July). Changes in the spectrum of ASD are explained in terms of surface temperature and precipitation. Seasonal variation of aerosol radiative forcing and its climatic impacts have also been discussed.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S11069-022-05486-6", "year": 2022, "title": "A scoping review of flash floods in Malaysia: current status and the way forward", "abstract": "Flash floods are not only the deadliest weather-related hazard but also one of the leading challenges with which governments and societies need to cope. Flash floods occur within a very limited time, which is insufficient to enable effective warnings and preparedness. Flash floods have become, for many reasons, the most frequent form of natural disaster in Malaysia, considerably affecting humans, property, and the economy. Modeling flash flood phenomena in the tropics is challenging due to the high topographic and meteorological complexity of these regions. The uncertain definition boundary of the monsoon flood and the multidisciplinary nature of flash flood studies also increase the challenge of the reviewing process. In this study, a systematic methodology was developed to review flash floods in Malaysia by considering all the possible related issues. This study revealed a gap in the data analysis of flash floods and that related studies in Malaysia are still not highly developed. Accordingly, the creation of a comprehensive Malaysian flash flood dataset is recommended to advance flash flood studies, modeling, and forecasting. Rainfall analysis based on Global Precipitation Measurement and Tropical Rainfall Measuring Mission data of different intensities also confirmed the high variability of rainfall in Malaysia. The highest variability in the hourly-based rainfall dataset was observed in the central region. The information and findings presented here will be useful for interested hydrologists and decision-makers by enabling better water management. Additionally, the proposed recommendations for future research could pave the way for a better understanding of flash floods in Malaysia, and the method could be applied in different river basins worldwide.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/MET.2039", "year": 2021, "title": "Unprecedented heavy rainfall event over Yamunanagar, India during 14 July 2016: An observational and modelling study", "abstract": "Extreme rainfall events have posed several serious threats to many populated and urbanized areas in the world including the Indian subcontinent. Therefore, accurate predictions of their intensity and areas of influence are important for flood-prone risk assessments. On 14 July 2016, heavy to exceptionally heavy rainfall occurred in Yamunanagar (30.16 N, 77.29 E), located in the state of Haryana in North India, which led to widespread disruption of communication, electricity, inundation of houses, and so forth. The present paper aims at examining observational, synoptic, thermo-dynamical, and numerical features associated with this devastating rainfall episode. The analysis found that during extreme rainfall episodes, a trough in mid-tropospheric westerlies and a strong low-level atmospheric monsoonal flow seem to have strongly interacted with each other, creating a strong convergence zone near study areas that led to a severe rainstorm. The quasi-stationary supercells were also noticed due to continuous moisture incursions from the Bay of Bengal and orographic uplift over the Himalayas near Yamunanagar. A deep layer of wind shear interacts dynamically with the convergence zone and leads to a potential rainstorm. Thermodynamic indices indicate high instability over the heavy rainfall area. The dynamics of this event were studied in detail by using three-dimensional variational data assimilation within the weather research and forecasting model, configured with triple two-way nesting domains (27, 9, and 3 km). The model results show that the weather research and forecasting model satisfactorily captures the quantitative precipitation (300 mm) in 24 h over the Yamunanagar region as compared with observation (365 mm).", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.AGWAT.2021.107080", "year": 2021, "title": "Evaluation of various meteorological datasets in estimation yield and actual evapotranspiration of wheat and maize (case study: Qazvin plain)", "abstract": "Precipitation (P) and temperature (T) are important factors in agricultural studies, water resources, and ecosystems. Therefore, their accurate measurement and estimation are very important. In this study, GLDAS-AgMERRA, GLDAS-CRU, GLDAS-AgCFSR networked meteorological datasets were evaluated in estimating the yield and actual evapotranspiration (ETa) of wheat and maize plants and comparing them with Qazvin Synoptic Station information. For this purpose, the Qazvin Synoptic Station information from 1980 to 2010 and the climatic information of the mentioned sets was extracted for six scenarios (S1: P and potential evapotranspiration (ETp) of GLDAS-T of CRU,S2: P and ETP of GLDAS-T of AgMERRA, S3: P of GLDAS- T and ETP of CRU, S4: P of GLDAS- T and ETP of AgMERRA, S5: P and ETP of GLDAS- T of AgCFSR, S6: P of GLDAS- T and ETp of AgCFSR). These datasets data quality was evaluated using R2, NRMSE, and ME statistical parameters with Aqua Crop model outputs. The calculated statistical parameters showed that in estimating the yield of the simulated wheat plant using Scenario 2 and 4, for maize, scenarios 1 and 3 were better correlated with other scenarios. In terms of ETa, Scenario 3 for maize and Scenario 6 for wheat were better correlated. The results show that accurately networked meteorological datasets can be used to estimate crop yields.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1134/S0001433822090183", "year": 2022, "title": "Satellite Assessment of Some Environmental Parameters in the Region of the Iskitim Coal Mines in 20132020", "abstract": "This article discusses the use of multispectral data from Landsat 8, Sentinel 2, Aqua, and Terra satellites for monitoring the environment in areas of open-pit coal mines in the Iskitimsky district of Novosibirsk oblast for 20132020. The dynamics of changes in the values of the reflection coefficient (CR) from the surface and water bodies, the snow index NDSI during the snowmelt period, and the change in NDVI in summer are shown. The dynamics of changes in the aerosol optical depth (AOD) (aerosol optical thickness (AOT)) of CO and CH4 values in the atmosphere of the Iskitimsky district is shown using the Giovanni data analysis and visualization system. A satellite assessment of the state of the atmosphere revealed seasonal changes in the AOD with maximum values in April and July. It is shown that the highest concentrations of carbon monoxide in the atmosphere are observed in the winter months, as well as in the spring of March and April. A stable decrease in the concentration of carbon monoxide in the atmosphere over 7 years from 2014 to 2020 with a determination coefficient of R2 = 0.95 and an increase in the concentration of methane with a determination coefficient of R2 = 0.89 are shown.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JSAMES.2022.104164", "year": 2023, "title": "Environmental degradation of vegetation cover and water bodies in the semiarid region of the Brazilian Northeast via cloud geoprocessing techniques applied to orbital data", "abstract": "The spatiotemporal diagnosis of climate variability and environmental changes in arid and semiarid regions is essential to minimize pressures and impacts on natural ecosystems. Remote sensing techniques and satellite images allow the detection of such changes. The study evaluated spatio-temporally the processes of environmental degradation of vegetation cover and water resources via physical-hydric parameters at the surface using remote sensing techniques for the Northeast of Brazil (NEB). Geospatial data from TRMM and MODIS satellites/sensors, digital cloud processing of vegetation indices (NDVI), water (NDWI and MNDWI), and rainfall were performed for the period 2000 to 2019. The patterns identified in the study were evaluated by multivariate statistics and correlation. The NDVI showed the significant vulnerability of vegetation cover in the Northeastern Semiarid region, due to the intensification of droughts. The spectral behavior of NDVI is due to rainfall, confirmed by principal component analysis (PCA) and correlation. The NDWI and MNDWI detected the pattern of water availability in the semiarid region, with a critical reduction in water bodies. In the space-time analysis, the physical-hydric parameters showed a significant water deficit, followed by severe drought and prolonged drought. MNDWI was efficient and sensitive to open water content, especially in areas covered by water bodies concerning NDWI, and correlated with rainfall. The variability of rainfall directly impacted the dynamics and resilience of vegetation and water bodies in the Northeastern Semiarid region. The critical reduction of areas of water bodies, the increase of non-vegetated areas, and the pressures of anthropic activities are favored.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/ATMOS13060994", "year": 2022, "title": "Long-Term Variations of Meteorological and Precursor Influences on Ground Ozone Concentrations in Jinan, North China Plain, from 2010 to 2020", "abstract": "Ground-level ozone (O3) pollution in the North China Plain has become a serious environmental problem over the last few decades. The influence of anthropogenic emissions and meteorological conditions on ozone trends have become the focus of widespread research. We studied the long-term ozone trends at urban and suburban sites in a typical city in North China and quantified the contributions of anthropogenic and meteorological factors. The results show that urban O3 increased and suburban O3 decreased from 2010 to 2020. The annual 90th percentile of the maximum daily 8-h average of ozone in urban areas increased by 3.01 gm3year1 and, in suburban areas, it decreased by 3.74 gm3year1. In contrast to the meteorological contributions, anthropogenic impacts are the decisive reason for the different ozone trends in urban and suburban areas. The rapid decline in nitrogen oxides (NOX) in urban and suburban areas has had various effects. In urban areas, this leads to a weaker titration of NOX and enhanced O3 formation, while in suburban areas, this weakens the photochemical production of O3. Sensitivity analysis shows that the O3 formation regime is in a transition state in both the urban and suburban areas. However, this tends to be limited to volatile organic compounds (VOCs) in urban areas and to NOX in suburban areas. One reasonable approach to controlling ozone pollution should be to reduce nitrogen oxide emissions while strengthening the control of VOCs.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11356-022-20391-Y", "year": 2022, "title": "Response of enhanced vegetation index changes to latent/sensible heat flux and precipitation over Pakistan using remote sensing", "abstract": "For a sustainable development and ecological integrity, it is of worth importance to monitor land use/ land cover (LULC) changes and related landatmosphere fluxes. To serve this purpose, we have used moderate resolution imaging spectroradiometer (MODIS) retrievedenhanced vegetation index (EVI), MERRA-2 re-analysis surface heat fluxes (latent heat flux, sensible heat flux and specific humidity), TRMM rainfall data, and OMI retrieved aerosol index (AI) over Pakistan during 2000 to 2021. High EVI (0.66) is observed in May 2021 as compared to May 2000 over Muzaffarabad, Srinagar, north and northwest of Khyber Pakhtunkhwa, east of Punjab and along the Indus River in Sindh. The highest increase in vegetative area is observed in Baluchistan (~ 366%), followed by Manavadar (~ 60%), Khyber Pakhtunkhwa (~ 41%), Sindh (~ 37%), and Punjab (~ 20%) whereas Gilgit-Baltistan and Jammu and Kashmir show reduction in vegetative area by 21% and 11% respectively. The coefficient of determination (R2) is found to be highest between rainfall and latent heat flux (R2 = 0.59) followed by rainfall and specific humidity (R2 = 0.35), and rainfall and sensible heat flux (R2 = 0.06). The latent heat flux shows increasing trend at the rate of 0.003 Wm2 winter1, 0.0065 Wm2 pre-monsoon1 and 0.0272 Wm2 post-monsoon1 during 19802021 whereas sensible heat flux shows decreasing trend at the rate of 0.00056 Wm2 winter1, 0.00249 Wm2 pre-monsoon1 and 0.0037 Wm2 post-monsoon1 during 19802021. Specific humidity depicts increasing trend at the rate of 0.0002 Wm2 winter1, 0.0038 Wm2 pre-monsoon1 and decreasing trend at the rate of 0.0080 Wm2 post-monsoon1 during 19802021. The interannual variations in AI show highest AI of 2.28 in 2021 with maximum positive percentage anomaly of 28.06% during 2007.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.UCLIM.2023.101412", "year": 2023, "title": "Impact of mobility restrictions on NO2 concentrations in key Latin American cities during the first wave of the COVID-19 pandemic", "abstract": "Between March and June 2020, activity in the major cities of Latin America declined due to containment efforts implemented by local governments to avoid the rapid spread of COVID-19. Our study compared 2020 with the previous year and demonstrated a considerable drop in tropospheric NO2 levels obtained by the SENTINEL 5P satellite in major Latin American cities. Lima (47.5%), Santiago (36.1%), Sao Paulo (27%), Rio de Janeiro (23%), Quito (18.6%), Bogota (17.5%), Buenos Aires (16.6%), Guayaquil (15.3%), Medellin (14.2%), La Paz (9.5%), Belo Horizonte (7.8%), Mexico (7.6%) and Brasilia (5.9%) registered statistically significant decreases in NO2 concentrations during the study period. In addition, we analyzed mobility data from Google and Apple reports as well as meteorological information from atmospheric reanalysis data along with satellite fields between 2011 and 2020, and performed a refined multivariate analysis (non-negative matrix approximation) to show that this decrease was associated with a reduction in population mobility rather than meteorological factors. Our findings corroborate the argument that confinement scenarios may indicate how air pollutant concentrations can be effectively reduced and managed.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S12524-023-01681-5", "year": 2023, "title": "Aerosol Variability at Coastal Bhola Island (Bangladesh), an IGP Outflow Region", "abstract": "The aerosol optical depth (AOD) and Angstrom parameters are recognised to be pivotal factors in understanding the status of ambient aerosol concentrations over a certain place and depend not only on the local but also on large-scale atmospheric dynamics. Aerosol climatology was undertaken across coastal Bhola Island for 7 years (20142021), using data from the Aerosol Robotic Network (AERONET). This study provides a protracted scrutiny of daily, monthly, seasonal and inter-annual variations of the AOD and Angstrom parameters for Bhola. The observed columnar AOD was analysed to offer a hitherto unknown temporal picture of trends in aerosol pollution over Bhola. During the study period (20142021), the AOD value increased from 20152019 to 20202021. The AOD value was 0.70 except for 20142015 and 20192020. The seasonal mean AOD over Bhola was > 0.3, highest in January and February (winter) and lowest in July (monsoon). Coarse-mode fractions during winter and fine-mode fractions during rest, corroborate the seasonal pattern of AODs and (Angstrom wavelength exponent). The average was found to be > 1 during the inter-annual comparison, implying the ubiety and predominance of fine-mode aerosol. The average ' (second order Angstrom exponent) value was positive, with an overall cumulative count of 90% of the data having positive ' validating the pre-eminence of fine-mode aerosols. The (Angstrom turbidity coefficient) value proportionally varied with respect to AOD, whereas it was inversely proportional to the at a broader wavelength. The average varied between 0.2 and 0.4. The aerosols detected over the Bhola are of metropolitan/industrial, maritime, biomass combustion and dust origins, with proportionate inputs varying in various seasons. The current study data will be used for future investigations of Bholas aerosols, pollution load, climate and atmospheric environment. Thus, this study is important as it facilitates the baseline data for policymakers and model simulation for pollution load and climate change analysis.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S10661-023-11118-8", "year": 2023, "title": "Evaluation of MODIS combined DT and DB AOD retrievals and their association with meteorological variables over Qena, Egypt", "abstract": "The purpose of this study is to validate the daily Terra-MODIS level 2 combined dark target (DT) and deep blue (DB) aerosol optical depth (AOD) retrievals with a spatial resolution of 10 km against the ground-based AERONET AOD data to be used in evaluating the air pollution and impact of meteorological variables over Qena, Egypt, in 2019. The regression analysis demonstrated an accepted agreement between the MODIS and AERONET AOD data with a correlation coefficient (R) of 0.7118 and 74.22% of the collocated points fall within the expected error (EE) limits. Quality flag filtering and spatial and temporal collocation were found to have a significant impact on the regression results. Quality flag filtering increased R by 0.2091 and % within EE by 17.97, spatial collocation increased R by 0.0143 and % within EE by 1.13, and temporal collocation increased R by 0.0089 and % within EE by 4.43. By validating the MODIS AOD data seasonally and analyzing the temporal distribution of the seasonal AOD data to show the retrieval accuracy variations between seasons, it was found that the MODIS AOD observations overestimated the AERONET AOD values in all seasons, and this may be because of underestimating the surface reflectance. Perhaps the main reason for the highest overestimation in summer and autumn is the transportation of aerosols from other regions, which changes the aerosol model in Qena, making accurate aerosol-type assumptions more difficult. Therefore, this study recommends necessary improvements regarding the aerosol model selection and the surface reflectance calculations. Temperature and relative humidity were found to have a strong negative relationship with a correlation of 0.735, and both have a moderate association with AOD with a correlation of 0.451 and 0.356, respectively. Because Qena is not a rainy city, precipitation was found to have no correlation with the other variables.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/SU15054173", "year": 2023, "title": "Exploring the Impact of Winter Storm Uri on Power Outage, Air Quality, and Water Systems in Texas, USA", "abstract": "Texas was hit by a record-setting cold snap from the 1417 February 2021 after three decades that resulted in power outages, disruption of the public water systems, and other cascading effects. This study investigates the unprecedented impact of winter storm Uri on power outages, air quality, and water systems in Texas, USA. Analysis of the Parameter Regression of Independent Slopes Model (PRISM) gridded climate data showed that the average daily freezing temperature range was 019 C on 14 February 2021, with severe levels (1719 C) occurring in the Texas High Plains. Our results showed that the extreme freezing temperature persisted from 1417 February 2021, significantly affecting power operation and reliability, and creating power outages across Texas. Uri impacted the public water systems and air quality on time scales ranging from a few minutes to several days, resulting in 322 boiling notices. The air quality index level exceeded the standard limit by 51.7%, 61.7%, 50.8%, and 60% in DallasFort Worth, HoustonGalveston, Austin, and Lubbock regions. The level of the pollutants exceeded the EPA NAAQS standard allowable limits during winter storm Uri. In general, this study gives information on the governments future preparedness, policies, communication, and response to storm impacts on vulnerable regions and communities.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/RS15051262", "year": 2023, "title": "COVID-19 Pandemic: Impacts on Air Quality during Partial Lockdown in the Metropolitan Area of Sao Paulo", "abstract": "Air pollution has become one of the factors that most affect the quality of life, human health, and the environment. Gaseous pollutants from motor vehicles have a significantly harmful effect on air quality in the Metropolitan Area of Sao Paulo (MASP)Brazil. Motor vehicles emit large amounts of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs), the last three acting as the main tropospheric ozone (O3) precursors. In this study, we evaluated the effects of these pollutants on air quality in the MASP during the partial lockdown that was imposed to ensure the social distancing necessitated by the COVID-19 pandemic. We compared the monthly data for nitrogen dioxide (NO2) from the Ozone Monitoring Instrument (OMI) and CO, SO2, and BC from MERRA-2 for the period between April and May 2020 (during the pandemic) with the average for the same period for the (pre-pandemic) years 2017 to 2019 in the southeast region of Brazil. The meteorological and pollutant concentration data from the CETESB air quality monitoring stations for the MASP were compared with the diurnal cycle of three previous years, with regard to the monthly averages of April and May (2017, 2018, and 2019) and the same period in 2020, when the partial lockdown was first imposed in southeast Brazil. Our findings showed that there was a decrease in NO2 concentrations ranging from 10% to more than 60% in the MASP and the Metropolitan Area of Rio de Janeiro (MARJ), whereas in the Metropolitan Area of Belo Horizonte and Vitoria (MABH and MAV, respectively), there was a reduction of around 10%. In the case of the concentrations of CO and BC from MERRA-2, there was a considerable decrease (approx. 10%) during the period of partial lockdown caused by COVID-19 throughout almost the entire state of Sao Paulo, particularly in the region bordering the state of Rio de Janeiro. The concentration of SO2 from MERRA-2 was 5 to 10% lower in the MASP and MARJ and the west of the MABH, and there was a decrease of 30 to 50% on the border between the states of Sao Paulo and Rio de Janeiro, while in the MAV region, there was an increase in pollutant levels, as this region was not significantly affected by the COVID-19 pandemic. Sharp reductions in the average hourly concentrations of CO (38.8%), NO (44.9%), NO2 (38.7%), and PM2.5 (6%) were noted at the CETESB air quality monitoring stations in the MASP during the partial lockdown in 2020 compared with the hourly average rate in the pre-pandemic period. In contrast, there was an increase of approximately 16.0% in O3 concentrations in urban areas that are seriously affected by vehicular emissions, which is probably related to a decrease in NOx.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/GEOHAZARDS4020012", "year": 2023, "title": "Earth Observation Data Synergy for the Enhanced Monitoring of Ephemeral Water Bodies to Anticipate Karst-Related Flooding", "abstract": "With the increasing availability and diversity of satellite imagery, the multisensor fusion of data can more effectively address the improved monitoring of temporary water bodies. This study supports the attempt to apply well established methods to detect spatial and temporal changes in ephemeral shallow lakes in lowland karst terrain, as well as to improve the understanding concerning the dynamics of water storage and hydrological mechanisms during extreme precipitation events. Based on the joint analysis of Copernicus Sentinel SAR and optical mission data, as well as soil moisture and EO-based rainfall observations over the period of 20152020, we demonstrated the control of the karst system on the ephemeral lake appearances in the broader area of Chalkida (Evvia, Greece). A connection between the prolonged and extended water coverage in the ephemeral lakes and flooding in the area is documented. Our EO-supported findings may serve as indicators for flood alerts in future extreme precipitation events, improving responses in cases of emergencies.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/9781118872086.CH20", "year": 2014, "title": "NASA Giovanni: A Tool for Visualizing, Analyzing, and Intercomparing Soil Moisture Data", "abstract": "As part of two NASA-funded projects, with team members who are end users from the National Oceanic and Atmospheric Administration (NOAA) National Weather Service (NWS) and the U.S. Department of Agriculture (USDA) World Agricultural Outlook Board (WAOB), a number of level 3 (gridded) soil moisture products have been incorporated into a beta prototype Giovanni portal. The purpose of this effort, beyond satisfying the requirements of the projects, is to create an environment, as part of the NASA Giovanni family of portals that facilitates intercomparisons and other uses of soil moisture products. This chapter provides some additional details on Giovanni. It describes the data products currently available in the Giovanni Intercomparison of Soil Moisture Products portal, and illustrates the portal's user interface and currently available services. The chapter then focuses on two examples of how the portal might be used for and facilitate hydrologic applications.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.4209/AAQR.2020.06.0295", "year": 2021, "title": "Impact of COVID-19 on the Air Quality over China and India Using Long-term (2009-2020) Multi-satellite Data", "abstract": "ABSTRACT We have examined the air quality over China, India and demonstrated marked differences in levels of air pollution resulted from the COVID-19 restrictions during DecemberApril, 201920 to that of 11 years mean of 200919. The criteria air quality indicators i.e., nitrogen dioxide (NO2), sulphur dioxide (SO2), Aerosol Index (AI) and aerosol optical depth (AOD) data are retrieved from the Ozone Monitoring Instrument (OMI), TROPOspheric Monitoring Instrument (TROPOMI), and MODerate Resolution Imaging Spectroradiometer (MODIS) sensor on the Terra and Aqua satellites, respectively. Over China, during COVID-19 lockdown a significant drop in columnar abundances of tropospheric NO2 (37%), SO2 (64%) and AOD (8%) for 2020 in comparison to 11 years mean (200919) has been observed. A noticeable difference in NO2 column burden is seen over SE (35%), NE (33%), NW (13%) and SW (5%) China. Over the SE and NE China, both NO2 and SO2 levels decreased dramatically in 2020 from that of 200919, by more than 40% and 65%, respectively, because of both stricter regulations of emissions and less traffic activity due to reduced social and industrial activities during COVID-19 restrictions. In contrast, the curve of monthly mean tropospheric columnar burden of NO2 and SO2 over India has shown moderate reduction of 16% and 20%, respectively because lockdown came into effect much later in March 2020. The mean NO2 and SO2 over IGP region is found to be 25% higher than whole Indias mean concentration due to large scale urban settlement and crop burning events. The statistical t-test analysis results confirm significant (p < 0.05) improvements in AQ during lockdown. The COVID-19 pandemic provided an unprecedented opportunity to investigate such large-scale reduction in emissions of trace gases and aerosols. Therefore, it is important to further strengthen environmental policies to tackle air quality, human health, and climate change in this part of the world.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S10346-022-01968-7", "year": 2022, "title": "Mapping the landslide susceptibility considering future land-use land-cover scenario", "abstract": "The landslide susceptibility (LS) of any mountainous region is significantly affected by the land-use land-cover (LULC) change. Recently, LULC change effects on landslides have been investigated by many researchers. However, the future prediction of the LS using these LULC changes has not been quantified. The main objective of this study is to predict the future LS map considering the future LULC change scenario for the Tehri region, India. To achieve this objective, we first prepared a geospatial database of past landslide events. These events data were clustered into three major temporal categories, 20052010, 20102015, and 20152020. Second, the artificial neural network (ANN) approach was adopted to prepare LS maps for the years 2010, 2015, and 2020. Then, for the same years, LULC maps were also developed. Third, the future scenario of LULC for the year 2030 was simulated using the ANN-cellular automata model, and the future LULC changes were derived using the change detection technique. Finally, the future LS map for 2030 was projected using derived future LULC changes. The LULC change results reveal that the region is expected to see a significant growth in the built-up area by 34.1%, water body by 6.3%, and agriculture land by 1%. Further, a shrink in dense forest area by 2.4% and sparse forest area by 0.9% is expected in the future. Additionally, the projected LS results reveal a 33% increment in the very high LS zone. This information about the increase in future LS due to rapid urban growth in the mountains can help the various government agencies to scientifically plan the various developmental activities.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/ATMOS11101068", "year": 2020, "title": "Mid-Century Changes in the Mean and Extreme Climate in the Kingdom of Saudi Arabia and Implications for Water Harvesting and Climate Adaptation", "abstract": "The Kingdom of Saudi Arabia (KSA) is a water-scarce region with a dry, desert climate, yet flood-producing precipitation events and heat extremes lead to loss of life and damages to local infrastructure, property and economy. Due to its distinctive natural and man-made spatial features (e.g., coastal features, wadis, agricultural areas) studying changes in the mean climate and extreme events requires higher-resolution climate projections than those available from the current generation of Earth System Models. Here, a high-resolution convection-permitting regional climate model is used to downscale the middle of the 21st century (20412050) climate projections of the Community Earth System Model (CESM) under representative concentration pathway (RCP) 8.5 and for a historical time period (20082017) focusing on two months (August and November) within KSAs dry-hot and wet seasons, where extreme events have historically been observed more frequently. Downscaling of climate reanalysis is also performed for the historical time period (20082017) to evaluate the downscaling methodology. An increase in the intensity and frequency of precipitation events is found in August by mid-century, particularly along the mountainous western coast of KSA, suggesting potential for water harvesting. Conversely, the northern flank of the Empty Quarter experiences a noticeable reduction in mean and extreme precipitation rates during the wet season. Increasing August heat index is found to particularly make regional habitability difficult in Jeddah by mid-century.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S10661-021-09005-1", "year": 2021, "title": "Drought dynamics of Northwestern Teesta Floodplain of Bangladesh: a remote sensing approach to ascertain the cause and effect", "abstract": "Drought is an affliction for a region that primarily depends on agriculture as economic activity. Commonly monitoring and characterizing of drought is performed by only analyzing the meteorological aspect, assuming precipitation as the primary source of water. However, in riverine Bangladesh, this can lead to an erroneous conclusion, as there is a multitude of available water sources. Consequently, in this study, vegetation condition (Standard Vegetation Index), soil moisture (Soil Moisture Index), and precipitation (Standard Precipitation Index) are separately investigated from 2003 to 2019, in the Northwestern Teesta floodplain. Subsequently, statistical regression analysis is performed to determine the relationships between different aspects of drought. In addition, information obtained from field visits and expert opinions has also been assimilated. Analysis of vegetation and soil moisture condition presents a progressively improving scenario. However, SPI shows an incessant decline in meteorological drought conditions, especially after 2007. Evidently, regression analysis does not provide any indication of an interrelationship between the studied agricultural and meteorological parameters. Presumably, this absence is instigated because the study area is highly irrigated as the groundwater table is suitably near the surface and the existence of nearby Teesta river allows for the utilization of surface water. Moreover, the cropping pattern is shifting toward crops that require much less water and to places where soil moisture is scarce. Thus, this study addresses the gap in knowledge regarding the nature of agricultural drought and the dynamics of different aspects of drought which will be invaluable for the water management and agricultural policy in the study area as well as other regions with a similar backdrop.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.ATMOSRES.2020.105296", "year": 2021, "title": "Simulation of an extreme dust episode using WRF-CHEM based on optimal ensemble approach", "abstract": "Extreme dust episodes have been noticeably increasing in recent years. Dust burden during such events imparts several threats to the environment and human health. Therefore, forecast of such extreme events becomes of utmost importance to minimise the adverse impact on various socio-economy sectors. In the present study model experiments have been carried out for the simulation of an extreme dust episode that emanated over the western Indian region that coupled with previously transported dust from the West Asia region and resulted in the highly degraded air quality over the Indian region. For this purpose four ensemble members, using Weather Research and Forecasting model fully coupled with chemistry (WRF-CHEM), have been generated for identical model configuration but for the perturbed initial conditions. Model performance has been evaluated with respect to the available ground based measurements from Central Pollution Control Board (CPCB) and the Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA2) data sets using standard statistical measures. Ensemble spread is noted amongst the four ensemble members generated based on 4 varying initial conditions, therefore it is suggested to use ensemble mean forecast for the dust storm monitoring and analysis. It is revealed from the analysis based on the categorical validation scheme that the WRF-CHEM simulated dust load is able to capture the locational accuracy with respect to the reanalysis/observational data sets over Indian subcontinent fairly well with 0% false alarm ratio, 7892% probability of detection and 7990% accuracy. It is noted that thick blanket of dust load enveloped Northern part of India subsequent to the dust storm which resulted in substantially dropped ground reaching solar radiation (~100150 W/m2) and a consequential reduction in the surface temperature (~2 C). Further to this enhanced temperature in association with reduced relative humidity from 800 to 600 hPa has also been noted in response to the enhanced dust loading in the model simulations. Results obtained in the present study suggests that WRF-CHEM is able to simulate both the direct and semi-direct effects of dust aerosols reasonably well. Present work has implications for improved prediction skills of WRF-CHEM in simulating extreme dust episodes and investigating the impact of dust aerosols on weather and climate.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS13030424", "year": 2022, "title": "Exploring Meteorological Conditions and Human Health Impacts during Two Dust Storm Events in Northern Cape Province, South Africa: Findings and Lessons Learnt", "abstract": "Dust storms are meteorological hazards associated with several adverse health impacts including eye irritations, respiratory and cardiovascular disorders, and vehicular road accidents due to poor visibility. This study investigated relations between admissions from a large, public hospital that serves people living in Northern Cape and Free State provinces, South Africa during 2011 to 2017, and meteorological variables (temperature and air quality) during two dust storms, one in October 2014 (spring) and the second in January 2016 (summer), identified from the media as no repository of such events exists for South Africa. Distributed nonlinear lag analysis and wavelet transform analysis were applied to explore the relationships between hospital admissions for respiratory and cardiovascular diseases, eye irritation, and motor vehicle accidents; maximum temperature, and two air quality proxy measures, aerosol optical depth and Angstrom exponent, were used as ground-based air quality data were unavailable. Eye irritation was the most common dust-related hospital admission after both dust storm events. No statistically significant changes in admissions of interest occurred at the time of the two dust storm events, using either of the statistical methods. Several lessons were learnt. For this type of study, ground-based air quality and local wind data are required; alternative statistical methods of analysis should be considered; and a central dust storm repository would help analyze more than two events. Future studies in South Africa are needed to develop a baseline for comparison of future dust storm events and their impacts on human health.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.RSASE.2022.100757", "year": 2022, "title": "Effects of the COVID-19 lockdown and recovery on People's mobility and air quality in the United Arab Emirates using satellite and ground observations", "abstract": "The stringent COVID-19 lockdown measures in 2020 significantly impacted people's mobility and air quality worldwide. This study presents an assessment of the impacts of the lockdown and the subsequent reopening on air quality and people's mobility in the United Arab Emirates (UAE). Google's community mobility reports and UAE's government lockdown measures were used to assess the changes in the mobility patterns. Time-series and statistical analyses of various air pollutants levels (NO2, O3, SO2, PM10, and aerosol optical depth-AOD) obtained from satellite images and ground monitoring stations were used to assess air quality. The levels of pollutants during the initial lockdown (March to June 2020) and the subsequent gradual reopening in 2020 and 2021 were compared with their average levels during 20152019. During the lockdown, people's mobility in the workplace, parks, shops and pharmacies, transit stations, and retail and recreation sectors decreased by about 34%79%. However, the mobility in the residential sector increased by up to 29%. The satellite-based data indicated significant reductions in NO2 (up to 22%), SO2 (up to 17%), and AOD (up to 40%) with small changes in O3 (up to 5%) during the lockdown. Similarly, data from the ground monitoring stations showed significant reductions in NO2 (49% 57%) and PM10 (19% 64%); however, the SO2 and O3 levels showed inconsistent trends. The ground and satellite-based air quality levels were positively correlated for NO2, PM10, and AOD. The data also demonstrated significant correlations between the mobility and NO2 and AOD levels during the lockdown and recovery periods. The study documents the impacts of the lockdown on people's mobility and air quality and provides useful data and analyses for researchers, planners, and policymakers relevant to managing risk, mobility, and air quality.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.3390/ATMOS12101283", "year": 2021, "title": "Understanding the Trend of NO2, SO2 and CO over East Africa from 2005 to 2020", "abstract": "The atmospheric chemistry constituents of nitrogen dioxide (NO2), sulphur dioxide (SO2) and carbon monoxide (CO) are associated with air pollution and climate change. In sub-Saharan Africa, a lack of sufficient ground-based and aircraft observations has, for a long time, limited the study of these species. This study thus utilized satellite observations as an alternative source of data to study the abundance of these species over the East African region. The instruments used included the Ozone Monitoring Instrument (OMI), the Atmospheric InfraRed Sounder (AIRS), and the TROPOspheric Monitoring Instrument (TROPOMI). An investigation of trends in the data series from 2005 to 2020 was carried out using the sequential Mann-Kendall test while the Pearson correlation coefficient was used to compare the data records of the instruments. The analysis revealed no trend in NO2 (p > 0.05), a decreasing trend in SO2 (p < 0.05), a decreasing trend (p < 0.05) in CO closer to the surface (850 hPa to 500 hPa) and an increasing trend (p < 0.05) in CO higher up in the atmosphere (400 hPa to 1 hPa). There is likely a vertical ascent of CO. The correlation between the instrument records was 0.54 and 0.77 for NO2 and CO, respectively. Furthermore, seasonal fires in the savanna woodlands were identified as the major source of NO2 and CO over the region, while cities such as Kampala, Nairobi, and Bujumbura and towns such as Dar es Salaam and Mombasa were identified as important NO2 hotspots. Similarly, the active volcano at Mt. Nyiragongo near Goma was identified as the most important SO2 hotspot.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S41976-022-00066-5", "year": 2022, "title": "A Complete Study on the Costliest Super Cyclone Amphan (May 2020) with Its Devastating Impact on West Bengal, India", "abstract": "Amphan (1621 May 2020) is the most intense tropical storm in the history of West Bengal during recent decades (20112020). After the 1999 Odisha Super Cyclone (OSuC), it is also the most intense super cyclonic storm (SuCS) that has originated over the Bay of Bengal (BoB) and caused irreparable damages during the storm event. The intensification time of Amphan was slow initially, but it grew from category 1 to 5 in record time, just within 18 h. This paper highlights mainly the pre-disaster state-level preparedness and also the severity of cyclonic storm Amphan on West Bengal. To map the flooded areas of southern West Bengal, the Sentinel-1 SAR dataset have been analyzed in the Google Earth Engine (GEE) environment. The results derived from the pixel-based analysis show that nearly 1075 km2 of land has been inundated due to intense rainfall and storm surges during Amphan. The powerful high storm surge is also responsible for the embankment breaching, which is 160 km long along the coastal belt of West Bengal.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S40098-021-00566-Z", "year": 2021, "title": "Assessment of Landslides Along NH 29 in the Kevuza Area, Kohima, Nagaland", "abstract": "National Highway (NH) 29 is a strategic highway of India that runs from Assam to Manipur, through Nagaland. This highway, also known as the Asian Highway 1 (AH 1), connects India to the Southeast Asian countries via Myanmar. A section of the highway, located near the capital city of Kohima, was damaged by major landslides on 1st August 2018. Another landslide occurred in the same area on 4th August 2019, which totally blocked vehicular movement for nearly a month. In both instances, the area received heavy rainfall intermittently for some days preceding slope failure. Geologically, the area is made up of highly jointed and fractured Disang rocks that are composed predominantly of shales intercalated with minor beds of siltstone, and some clay pockets indicating weathering of these rocks. The slide material comprises a mixture of loose debris of shales and saturated clays. A multi-parameter study involving geotechnical, kinematic and joint analyses, slope mass rating, resistivity surveys, and remote sensing using an Unmanned Aerial Vehicle (UAV) was carried out to determine the factors responsible for the two landslide events in this area. The study finds that the soils, with low values of unconfined compressive strength, are one of the major contributors to slope failure in the area. Slope stability analyses demarcate the slopes of the study area as partially stable to highly unstable. Kinematic and joint analyses indicate that the rocks are structurally weak due to the presence of joints, which make them susceptible to wedge failure. Analyses of joints and slickensides confirm complex deformation taking place in the area. The study of satellite imagery of the study area, coupled with field evidences, indicate that the area is crossed with faults. The presence of one such fault and two confined aquifers was validated by resistivity surveys, which explains the shearing of the rocks and high degree of weathering of the country rocks. The low shear strength of the soils and saturation of other slope materials due to heavy rainfall led to the two landslides events.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.EJRH.2019.100634", "year": 2019, "title": "Multidisciplinary study with quantitative analysis of isotopic data for the assessment of recharge and functioning of volcanic aquifers: Case of Bromo-Tengger volcano, Indonesia", "abstract": "Study region\nThe Bromo-Tengger volcanic aquifer system, (East Java, Indonesia).\nStudy focus\nAndesitic volcanic aquifers in Indonesia are an important source of groundwater supply for the population. The artesian flow from high discharge springs facilitates the access for irrigation and drinking water but continuously flowing artesian wells exert an increasing pressure on the groundwater resource. Given the complexity of the volcanic edifice, a multidisciplinary approach including geological, hydrometeorological, hydrochemical and isotopic measurements was performed to characterise the hydrogeological functioning of the volcanos northern flank.\nNew hydrogeological insights for the region\nTwo main hydrogeological systems are identified: a system with perched aquifers in the lava flows and pyroclastic complex, supplying low discharge springs or infiltrating to a deep flow system. The latter system is unconfined and provides groundwater to the downstream plain that hosts a confined multi-layer volcano-sedimentary aquifer. The joint implementation of a quantitative isotopic approach and a groundwater budget allows characterising aquifer recharge along the whole volcano flank. It is mainly controlled by the rainfall distribution that peaks around 1200 m elevation. The caldera basin on the top of the volcano has a very limited contribution to recharge. A conceptual hydrogeological model is proposed and compared to the main concepts of volcanic islands. This study is a first step for further scientific and management discussions to implement protection policies on the Bromo-Tengger aquifer system.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1038/S41598-019-53112-6", "year": 2019, "title": "Non-deforestation drivers of fires are increasingly important sources of aerosol and carbon dioxide emissions across Amazonia", "abstract": "Deforestation rates have declined substantially across the Brazilian Legal Amazon (BLA) over the period from 20002017. However, reductions in fire, aerosol and carbon dioxide have been far less significant than deforestation, even when accounting for inter-annual variability in precipitation. Our observations and analysis support a decoupling between fire and deforestation that has exacerbated forest degradation in the BLA. Basing aerosol and carbon dioxide emissions on deforestation rates, without accounting for forest degradation will bias these important climate and ecosystem-health parameters low, both now and in the future. Recent increases in deforestation rate since 2014 will enhance such degradation, particularly during drought-conditions, increasing emissions of aerosol and greenhouse gases. Given Brazils committed Nationally Determined Contribution under the Paris Agreement, failure to account for forest degradation fires will paint a false picture of prior progress and potentially have profound implications for both regional and global climate.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ENGGEO.2021.106504", "year": 2022, "title": "The world's second-largest, recorded landslide event: Lessons learnt from the landslides triggered during and after the 2018 Mw 7.5 Papua New Guinea earthquake", "abstract": "Events characterized by widespread landslides provide rare but valuable opportunities to investigate the spatial and size distributions of landslides in relation to seismic, climatic, geological and morphological factors. This study presents a unique event inventory for the co-seismic landslides induced by the February 25, 2018 Mw 7.5 Papua New Guinea earthquake. The mainshock rupture was dominated by reverse fault motion, and this was also the case for the aftershocks. The latter also triggered widespread landslides in combination with rainfall during the period between February 26 and March 19. We mapped approximately 11,600 landslides of which, more than 10,000 were triggered by the mainshock, with a total failed planimetric area of about 145 km2. Such a large area makes this inventory the world's second-largest recorded landslide event after the 2008 Mw 7.9 Wenchuan earthquake, where the motion changed from predominantly thrust to strike-slip. Large landslides are abundant throughout the study area located within the remote Papua New Guinea Highlands. Specifically, more than half of the landslide population is larger than 50,000 m2 and overall, post-seismic landslides are even larger than their co-seismic counterparts. To understand the factors controlling the distribution of landslides' occurrence and size, we combine descriptive statistics as well as more rigorous bivariate and multivariate analyses. We statistically show that the 15-day antecedent precipitation plays a role in explaining the spatial distribution of co-seismic landslides. Also, we examine four strong aftershocks (Mw 6.0) within 9 days after the mainshock and statistically demonstrate that the cumulative effect of aftershocks is the main factor disturbing steep hillslopes and causing the initiation of very large landslides, up to ~5 km2. Overall, the dataset and the findings presented in this paper represent a step towards a holistic understanding of the seismic landslide hazard assessment of the entire Papua New Guinea mainland.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/ATMOS11010059", "year": 2020, "title": "Effects of ozone and clouds on temporal variability of surface UV radiation and UV resources over Northern Eurasia derived from measurements and modeling", "abstract": "Temporal variability in erythemal radiation over Northern Eurasia (4080 N, 10 W180 E) due to total ozone column (X) and cloudiness was assessed by using retrievals from ERA-Interim reanalysis, TOMS/OMI satellite measurements, and INM-RSHU chemistryclimate model (CCM) for the 19792015 period. For clear-sky conditions during spring and summer, consistent trends in erythemal daily doses (Eery) up to +3%/decade, attributed to decreases in X, were calculated from the three datasets. Model experiments suggest that anthropogenic emissions of ozone-depleting substances were the largest contributor to Eery trends, while volcanic aerosol and changes in sea surface temperature also played an important role. For all-sky conditions, Eery trends, calculated from the ERA-Interim and TOMS/OMI data over the territory of Eastern Europe, Siberia and Northeastern Asia, were significantly larger (up to +58%/decade) due to a combination of decrease in ozone and cloudiness. In contrast, all-sky maximum trends in Eery, calculated from the CCM results, were only +34%/decade. While Eery trends for Northern Eurasia were generally positive, negative trends were observed in July over central Arctic regions due to an increase in cloudiness. Finally, changes in the ultraviolet (UV) resources (characteristics of UV radiation for beneficial (vitamin D production) or adverse (sunburn) effects on human health) were assessed. When defining a UV optimum condition with the best balance in Eery for human health, the observed increases in Eery led to a noticeable reduction of the area with UV optimum for skin types 1 and 2, especially in April. In contrast, in central Arctic regions, decreases in Eery in July resulted in a change from UV excess to UV optimum conditions for skin types 2 and 3.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S00445-018-1242-0", "year": 2018, "title": "Long-term eruptive trends from space-based thermal and SO2 emissions: a comparative analysis of Stromboli, Batu Tara and Tinakula volcanoes", "abstract": "Batu Tara (Indonesia) and Tinakula (Solomon Island) are two poorly known volcanoes with morphologies and short-term eruptive activity similar to Stromboli (Italy). However, quantitative information about their long-term eruptive behaviour is limited, making the comparisons with Stromboli descriptive and based on short periods of observations. Here, we use over a decade of satellite data to measure and compare the radiant flux (20002017) and the SO2 mass (20042017) of all three volcanoes. The combined analysis of volcanic radiant power (from MODIS data) and SO2 flux (from OMI data) reveals different long-term eruptive trends and contrasting ratios of SO2/VRP. These data indicate that the eruptive mechanisms operating at each volcano are quite different. The persistent open-vent activity of Stromboli volcano is episodically interrupted by flank eruptions that drain degassed magma stored in the very shallow portion of the central conduit. In contrast, a long-lasting exponential decay of both VRP and SO2 flux observed at Batu Tara is consistent with the eruption of undegassed magma from a deep, closed magma chamber, whilst Tinakula displays multiple year-long eruptive phases, characterised by evolving gas/thermal ratios and an eruptive intensity increasing with time. Magma budget calculations for the latter volcano are consistent with eruption from a volatile-zoned magma chamber, coupled with periods of gas/magma accumulations at depth. Our results suggest that the combined analysis of satellite thermal/gas data provides a valuable tool for decrypting the long-term volcanic dynamics that could remain hidden over shorter timescales.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/RS12061026", "year": 2020, "title": "Changes in Atmospheric, Meteorological, and Ocean Parameters Associated with the 12 January 2020 Taal Volcanic Eruption", "abstract": "The Taal volcano erupted on 12 January 2020, the first time since 1977. About 35 mild earthquakes (magnitude greater than 4.0) were observed on 12 January 2020 induced from the eruption. In the present paper, we analyzed optical properties of volcanic aerosols, volcanic gas emission, ocean parameters using multi-satellite sensors, namely, MODIS (Moderate Resolution Imaging Spectroradiometer), AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), TROPOMI (TROPOspheric Monitoring Instrument) and ground observations, namely, Argo, and AERONET (AErosol RObotic NETwork) data. Our detailed analysis shows pronounced changes in all the parameters, which mainly occurred in the western and south-western regions because the airmass of the Taal volcano spreads westward according to the analysis of airmass trajectories and wind directions. The presence of finer particles has been observed by analyzing aerosol properties that can be attributed to the volcanic plume after the eruption. We have also observed an enhancement in SO2, CO, and water vapor, and a decrease in Ozone after a few days of the eruption. The unusual variations in salinity, sea temperature, and surface latent heat flux have been observed as a result of the ash from the Taal volcano in the south-west and south-east over the ocean. Our results demonstrate that the observations combining satellite with ground data could provide important information about the changes in the atmosphere, meteorology, and ocean parameters associated with the Taal volcanic eruption.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S11869-020-00863-1", "year": 2020, "title": "Impact of lockdown on air quality in India during COVID-19 pandemic", "abstract": "First time in India, total lockdown was announced on 22 March 2020 to stop the spread of COVID-19 and the lockdown was extended for 21 days on 24 March 2020 in the first phase. During the total lockdown, most of the sources for poor air quality were stopped in India. In this paper, we present an analysis of air quality (particulate matter-PM2.5, Air Quality Index, and tropospheric NO2) over India using ground and satellite observations. A pronounced decline in PM2.5 and AQI (Air Quality Index) is observed over Delhi, Mumbai, Hyderabad, Kolkata, and Chennai and also a declining trend was observed in tropospheric NO2 concentration during the lockdown period in 2020 compared with the same period in the year 2019. During the total lockdown period, the air quality has improved significantly which provides an important information to the cities administration to develop rules and regulations on how they can improve air quality.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1175/BAMS-D-18-0113.1", "year": 2019, "title": "A sea level stratospheric ozone intrusion event induced within a thunderstorm gust front", "abstract": "Ozone from a stratospheric intrusion (SI) reached sea level in association with a thunderstorm gust front during the predawn hours of 16 April 2018. The event caused surface ozone concentration increases of 30 to more than 50 ppbv in a matter of minutes in a band from approximately Richmond, Virginia, to Philadelphia, Pennsylvania. Peak hourly ozone concentrations reached 74 ppbv in northeastern Maryland despite absent photochemistry and ongoing convective activity. An intense jet stream with velocities >80 kt (41 m s(-1)) less than 1 km above ground level was observed associated with a deepening cyclone. Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), showed a filament of ozone with concentrations greater than 90 ppbv extending downward from the stratosphere to the lower troposphere. This SI filament became collocated with an ongoing severe squall line, and stratospheric ozone was transported directly to sea level when entrained into the squall-line gust front. Weather radar and in situ observations confirmed surface ozone increased with the thunderstorm gust front, while a concurrent reduction in carbon monoxide confirmed air within the gust front had stratospheric origins. While rare, such coupling events are important to troposphere-stratosphere exchanges and in overall atmospheric chemistry and climate. This may be the first event of its type and magnitude documented.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/GMD-13-5707-2020", "year": 2020, "title": "New strategies for vertical transport in chemistry transport models: application to the case of the Mount Etna eruption on 18 March 2012 with CHIMERE v2017r4", "abstract": "Abstract. Excessive numerical diffusion is one of the major limitations in the representation of long-range transport by chemistry transport models. In the present study, we focus on excessive diffusion in the vertical direction, which has been shown to be a major issue, and we explore three possible ways of addressing this problem: increasing the vertical resolution, using an advection scheme with anti-diffusive properties and more accurately representing the vertical wind. This study was carried out using the CHIMERE chemistry transport model for the 18 March 2012 eruption of Mount Etna, which released about 3 kt of sulfur dioxide into the atmosphere in a plume that was observed by satellite instruments (the Infrared Atmospheric Sounding Interferometer instrument, IASI, and the Ozone Monitoring Instrument, OMI) for several days. The change from the classical Van Leer (1977) scheme to the Despres and Lagoutiere (1999) anti-diffusive scheme in the vertical direction was shown to provide the largest improvement to model outputs in terms of preserving the thin plume emitted by the volcano. To a lesser extent, the improved representation of the vertical wind field was also shown to reduce plume dispersion. Both of these changes helped to reduce vertical diffusion in the model as much as a brute-force approach (increasing vertical resolution).", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/NHESS-19-775-2019", "year": 2019, "title": "A susceptibility-based rainfall threshold approach for landslide occurrence", "abstract": "Abstract. Rainfall threshold determination is a pressing issue in\nthe landslide scientific community. While major improvements have been made towards more reproducible techniques for the identification of triggering\nconditions for landsliding, the now well-established rainfall intensity or\nevent-duration thresholds for landsliding suffer from several\nlimitations. Here, we propose a new approach of the frequentist method for\nthreshold definition based on satellite-derived antecedent rainfall\nestimates directly coupled with landslide susceptibility data. Adopting a\nbootstrap statistical technique for the identification of threshold\nuncertainties at different exceedance probability levels, it results in\nthresholds expressed as AR = ()S(), where AR is antecedent rainfall (mm), S is\nlandslide susceptibility, and are scaling parameters, and\n and are their uncertainties. The main\nimprovements of this approach consist in (1) using spatially continuous\nsatellite rainfall data, (2) giving equal weight to rainfall characteristics\nand ground susceptibility factors in the definition of spatially varying\nrainfall thresholds, (3) proposing an exponential antecedent rainfall\nfunction that involves past daily rainfall in the exponent to account for\nthe different lasting effect of large versus small rainfall,\n(4) quantitatively exploiting the lower parts of the cloud of data points, most\nmeaningful for threshold estimation, and (5) merging the uncertainty on\nlandslide date with the fit uncertainty in a single error estimation. We\napply our approach in the western branch of the East African Rift based on\nlandslides that occurred between 2001 and 2018, satellite rainfall estimates\nfrom the Tropical Rainfall Measurement Mission Multi-satellite Precipitation\nAnalysis (TMPA 3B42 RT), and the continental-scale map of landslide\nsusceptibility of Broeckx et al. (2018) and provide the first regional rainfall\nthresholds for landsliding in tropical Africa.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/ACP-20-6037-2020", "year": 2020, "title": "Solar UV radiation measurements in Marambio, Antarctica, during years 20172019", "abstract": "Abstract. In March 2017, measurements of downward global irradiance of ultraviolet (UV) radiation were started with a multichannel GUV-2511 radiometer in Marambio, Antarctica (64.23 S; 56.62 W), by the Finnish Meteorological Institute (FMI) in collaboration with the Servicio Meteorologico Nacional (SMN). These measurements were analysed and the results were compared to previous measurements performed at the same site with the radiometer of the Antarctic NILU-UV network during 20002008 and to data from five stations across Antarctica. In 2017/2018 the monthly-average erythemal daily doses from October to January were lower than those averaged over 20002008 with differences from 2.3 % to 25.5 %. In 2017/2018 the average daily erythemal dose from September to March was 1.88 kJ m2, while in 2018/2019 it was 23 % larger (2.37 kJ m2). Also at several other stations in Antarctica the UV radiation levels in 2017/2018 were below average. The maximum UV indices (UVI) in Marambio were 6.2 and 9.5 in 2017/2018 and 2018/2019, respectively, whereas during years 20002008 the maximum was 12. Cloud cover, the strength of the polar vortex and the stratospheric ozone depletion are the primary factors that influence the surface UV radiation levels in Marambio. The lower UV irradiance values in 2017/2018 are explained by the high ozone concentrations in November, February and for a large part of October. The role of cloud cover was clearly seen in December, and to a lesser extent in October and November, when cloud cover qualitatively explains changes which could not be ascribed to changes in total ozone column (TOC). In this study, the roles of aerosols and albedo are of minor influence because the variation of these factors in Marambio was small from one year to the other. The largest variations of UV irradiance occur during spring and early summer when noon solar zenith angle (SZA) is low and the stratospheric ozone concentration is at a minimum (the so-called ozone hole). In 2017/2018, coincident low total ozone column and low cloudiness near solar noon did not occur, and no extreme UV indices were measured.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/ATMOS11010096", "year": 2020, "title": "UV Index Forecasting under the Influence of Desert Dust: Evaluation against Surface and Satellite-Retrieved Data", "abstract": "Human exposure to healthy doses of UV radiation is required for vitamin D synthesis, but exposure to excessive UV irradiance leads to several harmful impacts ranging from premature wrinkles to dangerous skin cancer. However, for countries located in the global dust belt, accurate estimation of the UV irradiance is challenging due to a strong impact of desert dust on incoming solar radiation. In this work, a UV Index forecasting capability is presented, specifically developed for dust-rich environments, that combines the use of ground-based measurements of broadband irradiances UVA (320-400 nm) and UVB (280-315 nm), NASA OMI Aura satellite-retrieved data and the meteorology-chemistry mesoscale model WRF-Chem. The forecasting ability of the model is evaluated for clear sky days as well as during the influence of dust storms in Doha, Qatar. The contribution of UV radiation to the total incoming global horizontal irradiance (GHI) ranges between 5% and 7% for UVA and 0.1% and 0.22% for UVB. The UVI forecasting performance of the model is quite encouraging with an absolute average error of less than 6% and a correlation coefficient of 0.93. In agreement with observations, the model predicts that the UV Index at local noontime can drop from 10-11 on clear sky days to approximately 6-7 during typical dusty conditions in the Arabian Peninsula-an effect similar to the presence of extensive cloud cover.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.ETI.2018.08.006", "year": 2018, "title": "Application of satellite-based sulfur dioxide observations to support the cleantech sector: Detecting emission reduction from copper smelters", "abstract": "In this study, we present the result of the application of space-based sulfur dioxide (SO2) observations to evaluate the efficacy of cleantech solutions in reducing air polluting emissions from metal smelting. We analyze the Ozone Monitoring Instrument (OMI) satellite-based SO2 observations over Tsumeb (Namibia) and Bor (Serbia) copper smelters, where two sulfur-capture plants, designed to transform gaseous SO2 emissions into sulfuric acid, were implemented in 2015. We observe a reduction in the annual SO2 emissions by up to 90% after 2015 at both smelters, as a result of the implementation of the sulfuric acid plants. The OMI-based emission estimates are mostly in line with those reported at facility-level and reproduce the same year-to-year variability. This variability is driven by the changes in the copper production, the sulfur-to-copper ratio and by the technology employed to reduce the SO2 emissions. OMI observations are directly used by the company operating the sulfuric acid plants to confirm the efficacy of the employed technology using independent satellite-based observations.\n\nThe results demonstrate how satellite-based observations are able to detect relative changes in SO2 emissions and can be used to verify and complete existing emission informations. The approach presented here can be applied to other sources on global scale to support cleantech companies as well as decision-makers involved in environmental policies and sustainable development.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.7717/PEERJ.6507", "year": 2019, "title": "Enhancement of carbon monoxide concentration in atmosphere due to large scale forest fire of Uttarakhand", "abstract": "The richly forested Indian state of Uttarakhand experienced widespread forest fires in April to May 2016. The current study examines dispersion of carbon monoxide (CO) from the source regions of forest fire to distant places, using the Lagrangian particle dispersion model, FLEXPART. Atmospheric Infrared Sounder (AIRS) observations revealed that CO columnar concentrations had increased by almost 28 percentage during 24 April to 02 May 2016 with respect to the previous non-burning period of April 2016 at Uttarakhand. It is also seen that there is considerable enhancement of 45 percentage in average columnar concentration of CO during the burning period, compared to that in the previous 5 years as observed by AIRS. In the present study, concentrations of CO at different pressure levels and columnar CO over Uttarakhand during the forest fire event have been simulated using FLEXPART. The area averaged profile of model derived CO has been compared with the profile from AIRS onboard Aqua. Comparison between model derived columnar CO and satellite observations shows good agreement with coefficient of correlation (r) approximately 0.91 over the burnt areas. Further analysis using FLEXPART reveals that the transport of pollutants is towards north-eastern and eastern regions from the locations of forest fire events. Model derived vertical distribution of CO over Tibet, which is situated at the northeast of Uttarakhand, shows significant increase of CO concentration at higher altitudes around 3 kin from the mean sea level during the fire event. FLEXPART results show that the emissions from the Uttarakhand fires were transported to Tibet during the study period.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-19-1147-2019", "year": 2019, "title": "Cloud feedbacks in extratropical cyclones: insight from long-term satellite data and high-resolution global simulations", "abstract": "Abstract. A negative extratropical shortwave cloud feedback driven by changes in cloud\noptical depth is a feature of global climate models (GCMs). A robust positive\ntrend in observed liquid water path (LWP) over the last two decades across\nthe warming Southern Ocean supports the negative shortwave cloud feedback\npredicted by GCMs. This feature has been proposed to be due to transitions\nfrom ice to liquid with warming. To gain insight into the shortwave cloud\nfeedback we examine extratropical cyclone variability and the response of\nextratropical cyclones to transient warming in GCM simulations. Multi-Sensor\nAdvanced Climatology Liquid Water Path (MAC-LWP) microwave observations of\ncyclone properties from the period 19922015 are contrasted with GCM\nsimulations, with horizontal resolutions ranging from 7 km to hundreds of\nkilometers. We find that inter-cyclone variability in LWP in both\nobservations and models is strongly driven by the moisture flux along the\ncyclone's warm conveyor belt (WCB). Stronger WCB moisture flux enhances the\nLWP within cyclones. This relationship is replicated in GCMs, although its\nstrength varies substantially across models. It is found that more than\n80 % of the enhancement in Southern Hemisphere (SH) extratropical cyclone LWP in GCMs in\nresponse to a transient 4 K warming can be predicted based on the\nrelationship between the WCB moisture flux and cyclone LWP in the historical\nclimate and their change in moisture flux between the historical and warmed\nclimates. Further, it is found that that the robust trend in\ncyclone LWP over the Southern Ocean in observations and GCMs is consistent with changes in the moisture flux. We propose two cloud feedbacks acting\nwithin extratropical cyclones: a negative feedback driven by\nClausiusClapeyron increasing water vapor path (WVP), which enhances the\namount of water vapor available to be fluxed into the cyclone, and a feedback\nmoderated by changes in the life cycle and vorticity of cyclones under\nwarming, which changes the rate at which existing moisture is imported into\nthe cyclone. Both terms contribute to increasing LWP within the cyclone.\nWhile changes in moisture flux predict cyclone LWP trends in the current\nclimate and the majority of changes in LWP in transient warming simulations,\na portion of the LWP increase in response to climate change that is\nunexplained by increasing moisture fluxes may be due to phase transitions.\nThe variability in LWP within cyclone composites is examined to understand\nwhat cyclonic regimes the mixed-phase cloud feedback is relevant to. At a\nfixed WCB moisture flux cyclone LWP increases with increasing sea surface temperature (SST) in the half\nof the composite poleward of the low and decreases in the half equatorward of\nthe low in both GCMs and observations. Cloud-top phase partitioning observed\nby the Atmospheric Infrared Sounder (AIRS) indicates that phase transitions\nmay be driving increases in LWP in the poleward half of cyclones.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2020EA001624", "year": 2021, "title": "Antecedent Rainfall, Excessive Vegetation Growth and Its Relation to Wildfire Burned Areas in California", "abstract": "In recent years, California has experienced wildfire seasons of increasing frequency and magnitude, especially in terms of wildfire burned areas. Here, we investigate the precipitation and vegetation growth preceding each wildfire season for the 20012020 period to determine if antecedent rainfall led to enhanced vegetation growth in wildfire burned areas in California. Precipitation data from the Global Precipitation Measurement (GPM) Mission and Normalized Difference Vegetation Index (NDVI) and the Enhanced Vegetation Index (EVI) data are examined to determine if antecedent rainfall and vegetation were normal, above, or below average, for the peak wet (DecemberFebruary) and peak growth (MarchMay) periods preceding each wildfire season, as well as for the two previous wet and growth seasons. Then spatial correlations are done between precipitation and the vegetation indexes to determine the statistical significance of the relationships. Eleven of the 20 wildfire seasons were generally found to be preceded by above average levels of precipitation and vegetation growth. In three of the six seasons with more wildfire activities, linear regression model results show high positive correlations between precipitation and vegetation, suggesting that antecedent rainfall fueled vegetation growth that might have caused a significant impact on wildfire burned areas. Most of the larger wildfires in California, including the largest on record, exhibited positive correlations between antecedent rainfall and vegetation. Our results suggest that antecedent rainfall in California led to enhanced vegetation growth that later fueled more than half of the wildfire seasons analyzed in this study.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1117/12.2535487", "year": 2019, "title": "Preliminary validation of high-detailed GSA/Resurs-P tropospheric NO2 maps with alternative satellite measurements and transport simulations", "abstract": "An experiment for the retrieval of the high-detailed spatial NO2 distribution in the troposphere using measurements of the GSA instrument onboard the Resurs-P satellite was performed in 2016. The authors developed an algorithm to obtain the tropospheric NO2 2D distribution with the horizontal spatial resolution reaching 2,4 km for the first time at the world level and provided on a grid with a step of 120 m. The high spatial resolution of the NO2 space measurements for the first time allowed the identification of local sources of NO2 pollution and their plumes. The paper presents preliminary results of validation of the GSA high-detailed NO2 field obtained on September 29, 2016 for Hebei province, the North China Plain, which is the most NO2 polluted area in the world. To validate the coarse structures in the obtained NO2 field we performed comparisons with OMI NO2 observations having the resolution of 13 km x 24 km. The comparison confirmed the reliability of the GSA NO2 fields in general. For the validation of fine structures detected in the NO2 fields of GSA/Resurs-P, we are developing methods based on comparisons with chemical transport models. The paper presents preliminary comparison of the Resurs-P tropospheric NO2 field with simulation based on HYSPLIT dispersion model. For the solution of the problem, a high-detailed chemical transport model is under the development.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.EJRH.2021.100987", "year": 2022, "title": "Characterization of the hydro-geological regime of fractured aquifers in Benin (West-Africa) using multi-satellites and models", "abstract": "Study region\nFractured aquifers in Benin have emerged in the past decades as a critical resource because of the increasing domestic water needs, agriculture, and livestock breeding. Hence this study was undertaken in the poorly gauged and complex basement aquifers beneath the 9th latitude.\nStudy focus\nTo aid water resources management and sustainability, this study combined satellite remote sensing products with outputs from hydrological models and in situ measurement to assess the spatial and temporal patterns of water storage changes, including groundwater. The fractured aquifers hydrogeological regime is further analysed through monitoring wells series interpretation.\nNew hydrological insights for the region\nResults show considerable inter-annual variations in Terrestrial Water Storage (TWS) during the study period (20032019). Two uptrend intervals characterized by wet hydrological seasons from 2006 to 2013 and 20162019 with respectively, Sens slope values of 1.16 mm/yr and 4.47 mm/yr were observed. However, two downtrend intervals represented by dry hydrological seasons with Sens slopes of 1.01 mm/yr (20032006) and 1.19 mm/yr (20132016) were also observed. The inter-annual seasonality in land water storage components showed that unlike the 4 climatic seasons, the hydrogeological regime is affected by 3 seasons each year. The first dry season takes place from January to April-May (29.1 17.7 mm/yr) followed by the wet season (April-May to October-November: 41.6 26.4 mm/yr) and the last dry period, which is stronger (November to December: 53.7 31.6 mm/yr). Soil moisture (SM) and canopy water content (CW) declined during the 20082016 period, coinciding with decline in Tree cover areas, which dropped by 25.5% (3086.7 sqkm). Further from 2007 to 2014, the four monitoring wells have seen the groundwater level increased by, 1.44 m/yr, 2.0 m/yr, 3.2 m/yr, and 0.56 m/yr for the Affon, Zou, Okpara and Couffo sub-basins, respectively. The retrieved TWS and Water Global Assessment and Prognosis groundwater storage (WaterGap-GWS) sub-domains based on statistical decomposition was used to identify hidden patterns to improve knowledge on the climatic and hydrological conditions, which affected land water storage. Moreover, TWS, GWS and SM lost water 51%, 57% and 47% of the time, respectively, during the period and the storage potential is lower for the aquifers compared to the unsaturated zone. Precipitation is recognized as a primary driver of GWS (r = 0.69; = 0.05) in the region and a change in GWS is more likely to drive the CW and affect the vegetation greenness. Moreover, the anthropogenic pressure exacerbates Tree cover loss. Additionally, the Extra Tree regressor performs best in the groundwater storage change GWS prediction with a strong and positive Pearson Correlation Coefficient of 0.92. The basement aquifers assessment using the aforementioned approach has potential to support large-scale monitoring efforts for more reliable water resources management in the region.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/LAND11030317", "year": 2022, "title": "Likelihood of Transformation to Green Infrastructure Using Ensemble Machine Learning Techniques in Jinan, China", "abstract": "Rapid urbanization influences green infrastructure (GI) development in cities. The government plans to optimize GI in urban areas, which requires understanding GI spatiotemporal trends in urban areas and driving forces influencing their pattern. Traditional GIS-based methods, used to determine the greening potential of vacant land in urban areas, are incapable of predicting future scenarios based on the past trend. Therefore, we propose a heterogeneous ensemble technique to determine the spatial pattern of GI development in Jinan, China, based on driving biophysical and socioeconomic factors. Data-driven artificial neural networks (ANN) and random forests (RF) are selected as base learners, while support vector machine (SVM) is used as a meta classifier. Results showed that the stacking model ANN-RF-SVM achieved the best test accuracy (AUC 0.941) compared to the individual ANN, RF, and SVM algorithms. Land surface temperature, distance to water bodies, population density, and rainfall are found to be the most influencing factors regarding vacant land conversion to GI in Jinan.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/ATMOS11121270", "year": 2020, "title": "Analyzing Precipitation Changes in the Northern Tip of the Antarctic Peninsula during the 19702019 Period", "abstract": "Five decades of precipitation data are available from the Chilean Antarctic weather stations located in the northern tip of the Antarctic Peninsula. Data include daily accumulation and type of precipitation registered at the time of the observation at the Meteorological Antarctic Center located at Base Eduardo Frei Montalva, King George Island. This information allowed us to analyze not only the precipitation accumulation changes (always questionable in cold and windy regions) but also changes in precipitation days and precipitation phases (rain versus snow). The expo nential filter was applied to the monthly data to obtain decadal-like changes. The analysis revealed an overall increase in precipitation from 1970 to the early-1990s 60 7 mm (10 year)1 (p < 0.05) and 31 4 mm (10 year)1 (p < 0.05) and a negative trend between 1991 and 1999 with decreasing precipitation of 95 9 mm (10 year)1 (p < 0.05). On the other hand, while an increase in precipitation events also took place from 1970 to the early-1990s, there was a decreasing trend in precipitation events during the 2010s. This implies that the positive trend in precipitation accumulation registered during this period is due to the increasing extreme precipitation events. The precipitation type analysis shows an increase (decrease) in snow (rain) events from around the mid-1990s to mid-2010s during the summer season. These opposite trends were related to the summer cooling affecting the AP region.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SESCI.2021.03.001", "year": 2021, "title": "Investigating and modelling ground settlement response to groundwater dynamic variation in parts of Lagos using space-based retrievals", "abstract": "Ground settlement has impacted many infrastructures in Lagos. Rapid urbanisation has further compounded this problem. Monitoring and modelling of ground settlement will provide actionable information that can help to mitigate this problem. In this study, space-based retrievals were used to investigate the magnitude and spatial distribution of ground settlement and the role of groundwater depletion in Lagos. Using the SBAS technique, the ground settlement rates were computed based on the Sentinel-1 data acquired between 20152019. The GRACE-derived groundwater head changes between 20022017 was quantified, and the ground settlement response to groundwater depletion was modelled. The highest recorded groundwater depletion rate was 11 mm/year, while the highest observed ground settlement rate was 94 mm/year, indicating an intense rate of ground settlement up to the end of 2019. The statistical correlation between ground settlement and groundwater head changes is in the order of 0.4, which is a moderate positive correlation indicating a partial correlation between ground settlement and groundwater depletion. To model settlement, a one-dimensional approach was used to simulate the response of ground settlement to changes in groundwater level. The simulated results fairly correspond to the magnitude of observed settlement, confirming that factors other than groundwater depletion partly control ground settlement in Lagos.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S43247-022-00365-1", "year": 2022, "title": "Nontarget mass spectrometry and in silico molecular characterization of air pollution from the Indian subcontinent", "abstract": "Fine particulate-matter is an important component of air pollution that impacts health and climate, and which delivers anthropogenic contaminants to remote global regions. The complex composition of organic molecules in atmospheric particulates is poorly constrained, but has important implications for understanding pollutant sources, climate-aerosol interactions, and health risks of air pollution exposure. Here, comprehensive nontarget high-resolution mass spectrometry was combined with in silico structural prediction to achieve greater molecular-level insight for fine particulate samples (n = 40) collected at a remote receptor site in the Maldives during January to April 2018. Spectral database matching identified 0.5% of 60,030 molecular features observed, while a conservative computational workflow enabled structural annotation of 17% of organic structures among the remaining molecular dark matter. Compared to clean air from the southern Indian Ocean, molecular structures from highly-polluted regions were dominated by organic nitrogen compounds, many with computed physicochemical properties of high toxicological and climate relevance. We conclude that combining nontarget analysis with computational mass spectrometry can advance molecular-level understanding of the sources and impacts of polluted air.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S40808-022-01352-3", "year": 2022, "title": "Satellite observations for monitoring atmospheric NO2 in correlation with the existing pollution sources under arid environment", "abstract": "Monitoring of air pollutants using satellite data has been largely improved over the past few decades, which can provide deeper insights into the effects of anthropogenic activities on the air quality. The observations and measurements of atmospheric NO2 are poorly investigated in North Africa, therefore, the current study applied a multi-proxy approach to better understand of the ambient environment. This approach is based on satellite observations, chemical and biological analyses, and investigative information during fieldworks. The Aura satellite provides the basic data for the current study with fine resolution of atmospheric NO2 and O3 concentrations. The obtained results reveal noticeable increases of atmospheric NO2 values since the 2011, where its emission reaches the peak during summer season that is characterized by high anthropogenic activities. The study area has many sources for NO2 emissions, such as the urban region, traffic, as well as the NH3 emission that is in turn converted to NO2. Although the discharged and spreading wastewater (80,000 m3/day in summer) has a limited role in NO2 emissions, it represents an indicator of the anthropogenic activities. The wastewater analyses confirm the occurrence of nitrate (NO3), nitrite (NO2), and ammonia (NH4+), which provide an appropriate condition for NO2 release. The analyses of multi-climate datasets (previous records and the expected scenarios) reveal an increase of temperature accompanied by decrease of precipitation which confirmed the existence of climate change. Therefore, the study presents a set of suggestions to mitigate the release of NOx gases and achieve Net-Zero emissions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1371/JOURNAL.PONE.0271230", "year": 2022, "title": "Predicting flood damage using the flood peak ratio and Giovanni Flooded Fraction", "abstract": "A spatially-resolved understanding of the intensity of a flood hazard is required for accurate predictions of infrastructure reliability and losses in the aftermath. Currently, researchers who wish to predict flood losses or infrastructure reliability following a flood usually rely on computationally intensive hydrodynamic modeling or on flood hazard maps (e.g., the 100-year floodplain) to build a spatially-resolved understanding of the floods intensity. However, both have specific limitations. The former requires both subject matter expertise to create the models and significant computation time, while the latter is a static metric that provides no variation among specific events. The objective of this work is to develop an integrated data-driven approach to rapidly predict flood damages using two emerging flood intensity heuristics, namely the Flood Peak Ratio (FPR) and NASAs Giovanni Flooded Fraction (GFF). This study uses data on flood claims from the National Flood Insurance Program (NFIP) to proxy flood damage, along with other well-established flood exposure variables, such as regional slope and population. The approach uses statistical learning methods to generate predictive models at two spatial levels: nationwide and statewide for the entire contiguous United States. A variable importance analysis demonstrates the significance of FPR and GFF data in predicting flood damage. In addition, the model performance at the state-level was higher than the nationwide level analysis, indicating the effectiveness of both FPR and GFF models at the regional level. A data-driven approach to predict flood damage using the FPR and GFF data offer promise considering their relative simplicity, their reliance on publicly accessible data, and their comparatively fast computational speed.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1038/S41598-022-16850-8", "year": 2022, "title": "Spaceborne NO2 observations are sensitive to coal mining and processing in the largest coal basin of Russia", "abstract": "Coal use exacerbates several major environmental problems including build-up of greenhouse gases and air quality deterioration. Although Kuzbass (Siberia) is one of the largest exploited coal basins worldwide, the role of regional coal mining and processing in atmospheric pollution is unknown. We outlined the Kuzbass coal basin by spaceborne night-lights and revealed a regional, long-term tropospheric NO2 anomaly (20052018) by spaceborne NO2 column observations (hereafter NO2). The spatial agreement between NO2 and night-lights indicates that the anomaly is attributable to an agglomeration of coal quarries and the cities in Kuzbass, that are heavily reliant on coal. A positive relationship between NO2 and interannual coal production suggested that the anomaly was related to coal in Kuzbass; ~ 1.0% of annual coal production increase induced ~ 0.50.6% of NO2 enhancement. As coal production accelerated since 2010, NO2 exhibited strikingly similar annual increases over Kuzbass in 20102014 (7%) and 20152019 (15%), compared to 20052009. Conversely, Siberian cities lacking a coal industry followed the global trend of reducing NO2 for the same periods (5% and 14%, respectively), driven by fuel combustion improvements. Overall, we demonstrated that coal mining, processing and utilization can induce distinct tropospheric NO2 anomalies, detectable from space.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.7717/PEERJ.13969", "year": 2022, "title": "Satellite remote sensing of environmental variables can predict acoustic activity of an orthopteran assemblage", "abstract": "Passive acoustic monitoring (PAM) is a promising method for biodiversity assessment, which allows for longer and less intrusive sampling when compared to traditional methods (e.g., collecting specimens), by using sound recordings as the primary data source. Insects have great potential as models for the study and monitoring of acoustic assemblages due to their sensitivity to environmental changes. Nevertheless, ecoacoustic studies focused on insects are still scarce when compared to more charismatic groups. Insects acoustic activity patterns respond to environmental factors, like temperature, moonlight, and precipitation, but community acoustic perspectives have been barely explored. Here, we provide an example of the usefulness of PAM to track temporal patterns of acoustic activity for a nocturnal assemblage of insects (Orthoptera). We integrate satellite remote sensing and astronomically measured environmental factors at a local scale in an Andean Forest of Colombia and evaluate the acoustic response of orthopterans through automated model detections of their songs for nine weeks (March and April of 2020). We describe the acoustic frequency range and diel period for the calling song of each representative species. Three species overlapped in frequency and diel acoustics but inhabit different strata: canopy, understory, and ground surface level. Based on the acoustic frequency and activity, we identified three trends: (i) both sampled cricket species call at lower frequency for shorter periods of time (dusk); (ii) all sampled katydid species call at higher frequency for longer time periods, including later hours at night; and (iii) the diel acoustic activity span window seems to increase proportionally with dominant acoustic frequency, but further research is required. We also identified a dusk chorus in which all the species sing at the same time. To quantify the acoustic response to environmental factors, we calculated a beta regression with the singing activity as a response variable and moon phase, surface temperature and daily precipitation as explanatory variables. The response to the moon phase was significant for the katydids but not for the crickets, possibly due to differences in diel activity periods. Crickets are active during dusk, thus the effects of moonlight on acoustic activity are negligible. The response to precipitation was significant for the two crickets and not for the katydids, possibly because of higher likelihood of rain interrupting crickets shorter diel activity period. Our study shows how the local survey of orthopteran acoustic assemblages, with a species taxonomic resolution coupled with remote-sensing environmental measurements can reveal responses to environmental factors. In addition, we demonstrate how satellite data might prove to be a useful alternative source of environmental data for community studies with geographical, financial, or other constraints.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/RS15020449", "year": 2023, "title": "Predicting Short-Term Deformation in the Central Valley Using Machine Learning", "abstract": "Land subsidence caused by excessive groundwater pumping in Central Valley, California, is a major issue that has several negative impacts such as reduced aquifer storage and damaged infrastructures which, in turn, produce an economic loss due to the high reliance on crop production. This is why it is of utmost importance to routinely monitor and assess the surface deformation occurring. Two main goals that this paper attempts to accomplish are deformation characterization and deformation prediction. The first goal is realized through the use of Principal Component Analysis (PCA) applied to a series of Interferomtric Synthetic Aperture Radar (InSAR) images that produces eigenimages displaying the key characteristics of the subsidence. Water storage changes are also directly analyzed by the use of data from the Gravity Recovery and Climate Experiment (GRACE) twin satellites and the Global Land Data Assimilation System (GLDAS). The second goal is accomplished by building a Long Short-Term Memory (LSTM) model to predict short-term deformation after developing an InSAR time series using LiCSBAS, an open-source InSAR time series package. The model is applied to the city of Madera and produces better results than a baseline averaging model and a one dimensional convolutional neural network (CNN) based on a mean squared error metric showing the effectiveness of machine learning in deformation prediction as well as the potential for incorporation in hazard mitigation models. The model results can directly aid policy makers in determining the appropriate rate of groundwater withdrawal while maintaining the safety and well-being of the population as well as the aquifers integrity.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2022GB007391", "year": 2022, "title": "Lithogenic particle flux to the subantarctic Southern Ocean: A multitracer estimate using sediment trap samples", "abstract": "Mineral dust is a key source of essential micronutrients, particularly iron (Fe), for phytoplankton in the Southern Ocean. However, observations of dust deposition over the Southern Ocean are sparse, hindering assessments of its influence on marine biogeochemistry. We present a time series (20102019) of lithogenic particle flux estimates using sediment trap samples collected at 1,000 m depth at the subantarctic Southern Ocean Time Series (SOTS) site. Lithogenic flux was estimated using individual Fe, aluminium (Al), titanium, and thorium concentrations in sediment trap particles less than 1 mm in size. These tracers showed good agreement with one another, and their average was investigated as a proxy for mineral dust deposition. This multi-tracer average lithogenic flux exhibited strong seasonality, peaking in late spring and summer. No significant Fe enrichment was observed compared to the average upper continental crust, indicating that lithogenic material dominates particulate Fe flux at SOTS. Similar Fe:Al ratios in our samples compared to those reported in marine aerosols off southern Australia, coupled with particle trajectory analysis, suggested Australian dust constitutes the primary lithogenic source to SOTS sinking particles. Lead enrichment in our samples also highlighted an anthropogenic contribution to sinking particles, which might represent an additional aeolian source of more bio-available Fe to subantarctic waters. This study contributes a new long-term estimate of lithogenic particle fluxes and aeolian deposition over the subantarctic Southern Ocean. These estimates may enhance model representation of trace metal contribution to biogeochemical processes in the Southern Ocean.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1134/S0001433821120239", "year": 2021, "title": "Studying the Dynamics of Wildfires in Russia in 20012020 Taking into Account Climatic Factors", "abstract": "The features of large wildfires that occurred in Russia in 20012020 were studied on the base of satellite monitoring data. The contribution of the regions of the European part of Russia, as well as the Ural, Siberian, and Far East federal districts, to , 2, and PM2.5 emissions due to wildfires is estimated. It is established that the contribution of the Siberian Federal District into total emission volumes due to wildfires was prevailing from 2011 to 2017, and in some years it reached 60%. It is revealed that in 2020 wildfire emission volumes in the territory of the Far East Federal District exceeded 55% of the all-Russian emissions. An analysis of the features of anomalous wildfires is performed taking into account weather and climate factors. The relationship between large wildfires and weather and climatic factors, including blocking anticyclones, has been revealed. Using OMI (Aura satellite) data, it has been found that an aerosol plume due to large wildfires in Russia can spread over long distances and reach other continents.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S41651-018-0016-8", "year": 2018, "title": "Assessment of Runoff Pattern and Relationship to Sediment Yield of BhagirathiAlaknanda River Basin Using Geospatial Techniques", "abstract": "Erosion has been as a major issue in Bhagirathi and Alaknanda river basins due to high surface runoff. The river basins are located in the Uttarakhand state of India and have a total basin area of 19,066.5 km2. Sediment yield has been estimated and then correlated with the surface runoff using geospatial techniques during the period 20002015. Analytic hierarchy process (AHP) has been used to estimate the sediment yield. All required layers for assessment of runoff and sediment yield has been prepared in a geographical information system environment. Tropical Rain Measuring Mission (TRMM) rainfall data (0.25 0.25), Global Land Data Assimilation System (GLDAS) runoff data (0.25 0.25), Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) elevation data (30 m), and Landsat 5 and Landsat 8 satellite images (30 m) have been used to prepare rainfall maps, runoff maps, relief maps, and land use/land cover maps respectively. The study has shown that the sediment yield, as well as runoff, has a non-monotonic trend during 2000 to 2015. The highest runoff has been observed in the year 2013 whereas minimum runoff was in the year 2009. Correspondingly, the highest and lowest sediment yields were observed in the years 2013 and 2009 respectively. The northern part of the catchment was observed to be more vulnerable with respect to high sediment yield as well as runoff. As a whole, both river basins have a strong positive correlation between sediment yield and runoff with R2 values of 0.8. With respect to the findings, it can be concluded that some of the reservoirs for hydropower projects within these river basins may be in danger in the near future due to high sediment yields.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1155/2015/959284", "year": 2015, "title": "Tropospheric NO2 Trends over South Asia during the Last Decade (20042014) Using OMI Data", "abstract": "The focus of this study is to assess spatiotemporal variability of tropospheric NO2 over South Asia using data from spaceborne OMI during the past decade (20042015). We find an average value of NO2 1.0 0.05 1015 molec/cm2 and a significant decadal increase of 14%. The elevating NO2 pollution over the region is linked to rise in motor vehicles and industrial and agricultural activities and increase in biomass fuel usage. The observed seasonality of NO2 is associated with change in meteorological conditions and seasonal cycles of anthropogenic emissions. OMI data reveal a seasonal peak in spring followed by winter largely linked to metrological conditions and anthropogenic emissions from crop residue and biomass burning for heating purpose, and low concentration in summer is mostly attributed to meteorological conditions. Significant increase, up to 42%, in NO2 concentrations over northwestern IGB, is observed connected to large scale postmonsoon crop residue events of 2010 and 2012. It is seen that NO2 is mounting over all the hotspot locations and most of the cities. Dhaka shows the highest increase of 77% followed by Islamabad (69%), Kabul (68%), Korba (64%), Bardhaman (47%), and Lahore (40%). On the contrary, DG Khan has shown negative trend of 11%.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S00382-014-2120-X", "year": 2015, "title": "The relationship between African easterly waves and daily rainfall over West Africa: observations and regional climate simulations", "abstract": "The relationship between summer African easterly waves (AEWs) and daily rainfall is assessed in West Africa for 19982008 using various reanalyses, satellite-derived rainfall products, and a regional climate model (RCM) run at 90- and 30-km resolutions. 35 and 69 day AEWs are extracted by filtering daily 700 hPa meridional wind time series at 1W and 11.5N, and 1W and 17.5N, respectively. Both observed and simulated rainfall anomalies are of larger magnitude over West Africa during 35-d than 69-d AEWs. The RCM simulates larger rainfall rates in phase with the 35-d wave trough instead of ahead, unlike the observations, and overestimates the intensity and spatial coverage of rainfall associated with 69-d AEWs. The observed and simulated co-variability between 35-d (69-d) AEW activity and daily rainfall is strong (weak) and mostly located south (north) of 15N. However, the RCM overestimates the spatial coverage of the AEWrainfall relationship in the longitudinal (latitudinal) direction in the case of 35-d (69-d) AEWs. Observed and simulated daily intense rainfall events, extracted using a percentile threshold approach, are mostly located south of 15N during summer. The observed relationship between their frequency of occurrence and active 35-d AEWs is maximal west of 8E, while extends up to southern Chad in both RCM simulations. Their magnitude is also largely overestimated by the RCM, indicating an exaggerated coupling between the wave activity and the convection. Finally, observed and simulated 35-d AEWs establish the most favorable synoptic conditions for the development of intense rainfall events over West Africa.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSRES.2008.12.009", "year": 2009, "title": "Relationship between rainfall and lightning over central Indian region in monsoon and premonsoon seasons", "abstract": "Lightning activity and rainfall over the central Indian region (lat, 15.5 N to 25.5 N and lon, 75 E to 85 E) from the TRMM satellite have been analyzed. Ten years' data of monthly lightning and hourly averaged monthly rainfall from 1998 to 2007 have been used for analysis, which shows quite different relationships between lightning and rainfall in monsoon and premonsoon seasons in this region. Very good positive correlation is observed between rainfall and lightning during the premonsoon period, however, in the monsoon period a correlation between them is not so good. The different relationship between lightning and rainfall in the monsoon and premonsoon has been attributed to the low updraft during the monsoon period due to low cloud base height and low aerosol concentration during this period. This analysis shows that deep electrified convective systems do form over the central Indian region during active monsoon periods; however the relationship between convective rainfall and lightning frequency during this period is not as consistent as during the premonsoon period.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1177/0309133316658614", "year": 2017, "title": "Recent catastrophic landslide lake outburst floods in the Himalayan mountain range", "abstract": "Among the more complex and devastating interactions between climate and hydromorphological processes in mountain environments are landslide lake outburst floods (LLOFs), resulting from mass movements temporarily blocking a drainage system. This work reviews these processes in the Himalayas and highlights the high frequency of this type of phenomenon in the region. In addition, we analyse two recent catastrophic trans-national LLOFs occurring in the Sutlej river basin during 2000 and 2005. Based on high resolution satellite images, Tropical Rainfall Measuring Mission (TRMM), Moderate-Resolution Imaging Spectroradiometer (MODIS) derived evolution of snowline elevation and discharge data we reconstruct the timing and hydrometeorological conditions related to the formation and failure of landslide dams. Results showed that the 2005 flood, originating from the outburst of the Parchu Lake, was not related to heavy precipitation, but was likely enhanced by the rapid and late snowmelt of an unusually deep and widespread snowpack. The flood in 2000 was triggered by the outburst of an unnamed lake located on the Tibetan plateau, identified here for the first time. In this case, the outburst followed intense precipitation in the lake watershed, which raised the level of the lake and thus caused the breaching of the dam. As stream gauges were damaged during the events detailed discharge data is not available, but we estimated the peak discharges ranging between 1100 m3 s1 and 2000 m3 s1 in 2005, and 1024 m3 s1 and 1800 m3 s1 in 2000. These events caused significant geomorphic changes along the river valleys, with observed changes in channel width exceeding 200 m. Results also demonstrate that remotely-sensed data enables valuable large-scale monitoring of lake development and related hydrometeorological conditions, and may thereby inform early warning strategies, and provide a basis for flood risk reduction measures that focus on disaster preparedness and response strategies.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 9, "name": "Floods" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/2014JD022579", "year": 2015, "title": "Role of inertial instability in the West African monsoon jump", "abstract": "AbstractThe West African monsoon jump is a sudden shift in the latitude of the West African precipitation maximum from the Guinean coast near 4N into Sahel near 12N in late June or early July. An examination of reanalyses and observations indicates that the Sahel rainy season develops smoothly and the monsoon jump occurs because of an abrupt decrease in Guinean coast rainfall. We show that this abrupt end of the coastal rainy season occurs when inertial instability develops over the region, 1 month later than it develops in the vicinity of the marine Atlantic Intertropical Convergence Zone. The reason for this delay is the presence of the African easterly jet, which places strong negative meridional zonal wind gradients over the coast to preserve the inertially stable environment. When the African easterly jet moves farther north due to the seasonal solar forcing, these gradients weaken and then reverse to satisfy the threshold condition for inertial instability; the rapid end of the Guinean coast rainy season follows. The northward movement and intensity of the African easterly jet are controlled by the seasonal development of strong meridional land surface temperature gradients and are independent of the formation of the Atlantic cold tongue. This explanation for the West African monsoon jump relates the phenomenon to the shape and location of the African continent, including the low-latitude position of the Guinean coast and the large expanse of the continent to the north.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/NATURE21048", "year": 2017, "title": "Age, extent and carbon storage of the central Congo Basin peatland complex", "abstract": "Peatlands are carbon-rich ecosystems that cover just three per cent of Earths land surface1, but store one-third of soil carbon2. Peat soils are formed by the build-up of partially decomposed organic matter under waterlogged anoxic conditions. Most peat is found in cool climatic regions where unimpeded decomposition is slower, but deposits are also found under some tropical swamp forests2,3. Here we present field measurements from one of the worlds most extensive regions of swamp forest, the Cuvette Centrale depression in the central Congo Basin4. We find extensive peat deposits beneath the swamp forest vegetation (peat defined as material with an organic matter content of at least 65 per cent to a depth of at least 0.3 metres). Radiocarbon dates indicate that peat began accumulating from about 10,600 years ago, coincident with the onset of more humid conditions in central Africa at the beginning of the Holocene5. The peatlands occupy large interfluvial basins, and seem to be largely rain-fed and ombrotrophic-like (of low nutrient status) systems. Although the peat layer is relatively shallow (with a maximum depth of 5.9 metres and a median depth of 2.0 metres), by combining in situ and remotely sensed data, we estimate the area of peat to be approximately 145,500 square kilometres (95 per cent confidence interval of 131,900156,400 square kilometres), making the Cuvette Centrale the most extensive peatland complex in the tropics. This area is more than five times the maximum possible area reported for the Congo Basin in a recent synthesis of pantropical peat extent2. We estimate that the peatlands store approximately 30.6 petagrams (30.6 1015 grams) of carbon belowground (95 per cent confidence interval of 6.346.8 petagrams of carbon)a quantity that is similar to the above-ground carbon stocks of the tropical forests of the entire Congo Basin6. Our result for the Cuvette Centrale increases the best estimate of global tropical peatland carbon stocks by 36 per cent, to 104.7 petagrams of carbon (minimum estimate of 69.6 petagrams of carbon; maximum estimate of 129.8 petagrams of carbon2). This stored carbon is vulnerable to land-use change and any future reduction in precipitation7,8.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.QUAINT.2014.10.033", "year": 2015, "title": "Neotectonically triggered instability around the palaeolake regime in Central Kumaun Himalaya, India", "abstract": "Mass wasting often results from the combined effect of tectonic and climate processes. It has not only resulted in human casualties on large scale but has also ruined agricultural land and disrupted hydro power projects and other governmental as well as private property. Despite the belief that prevention is inevitably better than cure, decrease in future hazards requires proper dissemination of knowledge to the Himalayan inhabitants. Considering this, we investigated a part of Kumaun Himalaya to understand the cause of cloud burst induced mass movements along the Saryu River that took place on 18th August 2010 and subsequently on 1214th September, 2012. A number of Quaternary faults, e.g., Dulam fault (DF), Dulam Gadhera Fault (DGF) and Vongarh-Gason Fault (VGF) in the zone of a major thrust (Berinag Thrust) in the studied sector are invariably active as evident by various geomorphic features, e.g., saw cutting of host rocks, immature topography, deflecting river courses, ponding of ancient drainage, development of cascades, formation of unpaired fluvial terraces, and series of triangular fault facets. The fragile lithology, deep V shaped valleys, accelerating erosion and incision with higher uplift due to tectonic upheaval along the active faults are also responsible for rainfall induced catastrophes in the region. Additionally, morphometric analysis reveals that the Saryu basin is elongated and tilted. Further, the tectonic tilting and moderate to coarse drainage density may possibly be responsible for quicker runoff, amplified erosion, and subsequently increased flooding around the study area. We infer that the area is not only controlled by topography but may also have been affected by the hydraulic factors such as climate. In addition, the drainage is dominated mostly by first order streams which seem to be indicative of higher chances of flooding, as most of the water is concentrated in a single channel during monsoon season. We believe that the similar studies done in the other sectors will be helpful in reducing not only the huge loss of life but may also help in protecting ongoing and huge hydropower and other developmental projects in this newly born state.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S00704-018-2509-2", "year": 2019, "title": "Long-term study of aerosolcloudprecipitation interaction over the eastern part of India using satellite observations during pre-monsoon season", "abstract": "This study attempts to analyze possible aerosolcloudprecipitation interaction over the eastern part of India including Bhubaneswar city and the whole Odisha region primarily using a long-term satellite-based dataset from 2000 to 2016 during pre-monsoon period. Relationship between aerosol optical depth (AOD), rainfall, and cloud properties is examined by taking convectively driven rain events. The two-sample students t test is used to compute p value of datasets that are statically significant. Role of aerosols in governing cloud properties is analyzed through the variation of COD (cloud optical depth) and CER (cloud effective radius) in the AOD ranges 0.20.8. A relatively stronger and affirmative AODCER relationship is observed over Bhubaneswar city compared to Odisha region though the aerosols still play an appreciable role for the later too. The AODCOD relationship is weak over both the regions. For Odisha, relationships between aerosol and cloud parameters are insignificant irrespective of rainfall regimes. Fostering of heavy rainfall over these regions takes place due to invigoration and microphysical effect during pre-monsoon months, depending upon meteorological conditions. Liquid water content and presence of a mixed-phase zone, both seem to be quite important in the convectively driven precipitation over Odisha region including Bhubaneswar city.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10346-015-0584-3", "year": 2016, "title": "Lake outburst and debris flow disaster at Kedarnath, June 2013: hydrometeorological triggering and topographic predisposition", "abstract": "Heavy rainfall in June 2013 triggered flash flooding and landslides throughout the Indian Himalayan state of Uttarakhand, killing more than 6000 people. The vast majority of fatalities and destruction resulted directly from a lake outburst and debris flow disaster originating from above the village of Kedarnath on June 16 and 17. Here, we provide a systematic analysis of the contributing factors leading to the Kedarnath disaster, both in terms of hydrometeorological triggering and topographic predisposition. Topographic characteristics of the lake watershed above Kedarnath are compared with other glacial lakes across the north-western Himalayan states of Uttarakhand and Himachal Pradesh, and implications for glacier lake outburst hazard assessment in a changing climate are discussed. Our analysis suggests that the early onset of heavy monsoon rainfall (390 mm, June 1017) immediately following a 4-week period of unusually rapid snow cover depletion and elevated streamflow was the crucial hydrometeorological factor, resulting in slope saturation and significant run-off into the small seasonal glacial lake. Between mid-May and mid-June 2013, snow-covered area above Kedarnath decreased by around 50 %. The unusual situation of the lake being dammed in a steep, unstable paraglacial environment but fed entirely from snowmelt and rainfall within a fluvial dominated watershed is important in the context of this disaster. A simple scheme enabling large-scale recognition of such an unfavourable topographic setting is introduced. In view of projected 21st century changes in monsoon timing and heavy precipitation in South Asia, more emphasis should be given to potential hydrometeorological triggering of lake outburst and debris flow disasters in the Himalaya.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3402/TELLUSA.V67.26031", "year": 2015, "title": "Improved understanding of an extreme rainfall event at the Himalayan foothills a case study using COSMO", "abstract": "In recent years, an increased occurrence of loss and damage of property and human casualties over the southern rim area of the Himalayas, caused by landslides following intense rainfall events, has been reported. An analysis of Tropical Rainfall Measuring Mission (TRMM)-gridded rainfall data shows that events with an exceedance probability of 1.6% for 200 mm/d rainfall are common over this region during the monsoon season. An improved understanding of the mechanisms, which lead to such events, is important for their prediction and to estimate the impact of climate change on their recurrence. In this study, we analyse such an extreme precipitation event, which hit the Uttarakhand region of the central Himalayas on 13 September 2012. We use the operational regional weather forecast model COSMO at a convection-permitting resolution of 2.8 km to simulate this event. The spatial pattern of daily-accumulated precipitation and atmospheric state profiles simulated by the model compared well with the TRMM-gridded data and radiosonde observations, which adds confidence to our model results. Our analysis suggests a three-step mechanism leading to this event: (1) development of an easterly low-level wind along the Gangetic Plain caused by a low pressure system over the central Gangetic Plain; (2) convergence of moisture over the north-western part of India, leading to an increase of potential instability of the air mass along the valley recesses, which is capped by an inversion located above the ridgeline; and (3) strengthening of the north-westerly flow above the ridges, which supports the lifting of the potentially unstable air over the protruding ridge of the foothills of the Himalayas and triggers shallow convection, which on passing through adjacent folds initiates deep convection.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/01431161.2017.1306140", "year": 2017, "title": "Importance of satellite-retrieved rain/no-rain information on short-range weather predictions", "abstract": "The impact of assimilating rain (satellite-retrieved rainfall is greater than zero) and no-rain (satellite-retrieved rainfall is equal to zero) information retrieved from the Tropical Rainfall Measuring Mission (TRMM) 3B42 precipitation is assessed during Indian summer monsoon 2013 using the weather research and forecasting (WRF) model. Daily three parallel experiments are performed with and without satellite rainfall assimilation for short-range weather forecasts. Additional two experiments are performed daily to evaluate the sensitivity of cumulus parameterization on the WRF model predictions when precipitations are used for assimilation. Precipitation assimilation improves the 48 h low-level temperature, moisture, and winds predictions. Rainfall prediction is also improved over central India when satellite-retrieved rainfall information are assimilated compared to without rainfall assimilation (CNT) experiments. More improvements are seen in moisture forecasts when the KainFritsch (KF) cumulus convection parameterization scheme is used against the GrellDevenyi ensemble (GD) scheme, whereas for temperature and wind speed forecasts the Grell convection parameterization scheme performed better over the Indian region. Overall, precipitation assimilation improved the WRF model analysis and subsequent model forecasts compared with without precipitation assimilation experiments. Results show that no-rain observations also have a significant positive impact on short-range weather forecasts.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/JGRD.50634", "year": 2013, "title": "Impacts of woody plant encroachment on regional climate in the southern Great Plains of the United States", "abstract": "AbstractVegetation change can influence climate by altering the fluxes of mass and energy between ecosystems and the atmosphere. In the past century or so, rapid conversion of grasslands to woodland by woody species encroachment is one of the most important vegetation changes in the semiarid and arid regions of the world. The objective of this study is to investigate potential impacts of this widespread phenomenon on climate system in the southern Great Plains of the United States. The Regional Atmospheric Modeling System (RAMS) is used for this study. Grassland on the surface in RAMS is gradually replaced by woody species and RAMS is run a set of times, each with a different amount of encroachment. RAMS-simulated precipitation and air temperature are then analyzed. This study finds tha t over a 1 year period woody plant encroachment leads to increase in rainfall and the increase is statistically significant at many locations. Woody encroachment also has an overall warming effect, but increase in temperature is not statistically significant. Temperature and precipitation increase almost linearly with increasing encroachment on the surface. When grassland is completely replaced, annual accumulated precipitation increases by 23.6 mm and maximum air temperature rises by 0.13C averaged over the entire study area. In areas where encroachment occurs, averaged increases in accumulated precipitation and temperature are 58.2 mm and 0.27C, respectively. The largest increase in precipitation and strongest warming tend to be located in dry and encroached areas including central and northern Texas, and they reach as high as 213.6 mm and 0.68C, respectively. Decrease in surface albedo is found to be the most important factor that causes these changes.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S12040-011-0015-3", "year": 2011, "title": "Impact of additional surface observation network on short range weather forecast during summer monsoon 2008 over Indian subcontinent", "abstract": "The three dimensional variational data assimilation scheme (3D-Var) is employed in the recently developed Weather Research and Forecasting (WRF) model. Assimilation experiments have been conducted to assess the impact of Indian Space Research Organisations (ISRO) Automatic Weather Stations (AWS) surface observations (temperature and moisture) on the short range forecast over the Indian region. In this study, two experiments, CNT (without AWS observations) and EXP (with AWS observations) were made for 24-h forecast starting daily at 0000 UTC during July 2008. The impact of assimilation of AWS surface observations were assessed in comparison to the CNT experiment. The spatial distribution of the improvement parameter for temperature, relative humidity and wind speed from one month assimilation experiments demonstrated that for 24-h forecast, AWS observations provide valuable information. Assimilation of AWS observed temperature and relative humidity improved the analysis as well as 24-h forecast. The rainfall prediction has been improved due to the assimilation of AWS data, with the largest improvement seen over the Western Ghat and eastern India.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S11069-011-0064-6", "year": 2013, "title": "Extreme weather and economic well-being in rural Mozambique", "abstract": "Societies dependent on rain-fed agriculture are highly vulnerable to weather extremes; thus, linkages between rainfall variability and economic well-being merit close attention. The hypothesis of this paper is that rainfall patterns impact changes in income within our study region of central and northern Mozambique. Utilizing satellite-based estimates of rainfall analyzed within a GIS, we establish a 12-year rainfall climatology and calculate monthly rainfall anomalies for 419 villages during three growing seasons. We also approximate storm-total rainfall from tropical cyclones entering the Mozambique Channel. Hierarchical cluster analysis groups the villages according to the monthly rainfall anomalies and rainfall received from Cyclones Delfina and Japhet. Then, using data from the National Agricultural Survey of Mozambique conducted in 2002 and 2005, we relate rainfall and change in income through the calculation of Pearsons correlation coefficients and independent-samples t tests using village-groups produced by the cluster analysis. We find that no season closely approximates the 12-year climatology and that rainfall varied among the three seasons. Although most villages experience income declines, those affected by Delfina exhibit the worst economic performance, indicating that heavy rainfall from some tropical cyclones can have long-lasting negative effects on income. Additionally, receiving above-normal rainfall may hinder economic well-being more than below-normal rainfall. Our study identifies patterns in sub-national rainfall variability and economic well-being that enable a more detailed understanding of weather-related effects on socio-economic outcomes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 15, "name": "Severe Storms" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.RSE.2012.11.011", "year": 2013, "title": "Climate-driven chlorophyll-a changes in a turbid estuary: Observations from satellites and implications for management", "abstract": "Significant advances have been made in ocean color remote sensing of turbidity and water clarity for estuarine waters, yet accurate estimations of chlorophyll-a concentrations (Chla in mgm3) has been problematic, posing a challenge to the research community and an obstacle to managers for long-term water quality assessment. Here, a novel empirical Chla algorithm based on a Red-Green-Chorophyll-Index (RGCI) was developed and validated for MODIS and SeaWiFS observations between 1998 and 2011. The algorithm showed robust performance with two independent datasets, with relative mean uncertainties of ~30% and ~50% and RMS uncertainties of ~40% and ~65%, respectively, for Chla ranging between 1.0 and >30.0mgm3. These uncertainties are comparable or even lower than those reported for the global open oceans when traditional blue-green band ratio algorithms are used. A long-term Chla time series generated from SeaWiFS and MODIS observations showed excellent agreement between sensors and with in situ measurements. Substantial variability in both space and time was observed in the four bay segments, with higher Chla in the upper bay segments and lower Chla in the lower bay segments, and higher Chla in the wet season and lower Chla in the dry season. On average, river discharge could explain ~60% of the seasonal changes and ~90% of the inter-annual changes, with the latter mainly driven by climate variability (e.g. El Nino and La Nina years) and anomaly events (e.g. tropical cyclones). Significant positive correlation was found between monthly mean Chla anomalies and monthly Multivariate ENSO Index (MEI) (Pearson correlation coefficient=0.43, p<0.01, N=147), with high Chla associated with El Nino and lower Chla associated with La Nina. Further, a Water Quality Decision Matrix (WQDM) was established from satellite observations, providing complementary and more reliable information to the existing WQDM based on less synoptic and less frequent field measurements. The satellite-derived WQDM and long-term time-series data support the decision making efforts of the management agencies that regulate nutrient discharge to the bay. Similar approaches may be established for other estuaries where field data are much more limited than for Tampa Bay.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10236-015-0838-6", "year": 2015, "title": "Changes in local oceanographic and atmospheric conditions shortly after the 2004 Indian Ocean tsunami", "abstract": "This study examines changes in the local oceanographic and atmospheric conditions over the southern Bay of Bengal and adjacent Indian Ocean waters after the 2004 Indian Ocean tsunami based on satellite remote sensing data and atmospheric reanalysis fields. After the tsunami that occurred on 26 December 2004, the accumulated rainfall had a notably increase (600 mm per month) in January of 2005 over deep waters to the southeast of Sri Lanka. This rainfall increase after the tsunami was accompanied with cooling in the sea surface temperature (SST) (up to 2 C). Four-day averaged SST anomalies had a noticeable increase (14 C) after the tsunami over the deep waters to the southwest of the epicenter. Series of ocean atmospheric and biological variables changed successively after the change of SST. The chain of causality between the tsunami and the changes in the local atmospheric conditions is suggested.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1111/1752-1688.12398", "year": 2016, "title": "Assessment of the TRMM 3B42 Precipitation Product in Southern Brazil", "abstract": "The increase in the use of satellite-derived precipitation products generated by different methods and algorithms emphasizes the need for a deeper analysis of their quality and accuracy. Using the contingency table method, we evaluated the accuracy of versions 6 and 7 of the Tropical Rainfall Measuring Mission Precipitation (TRMM) 3B42 product in southern Brazil by comparing daily precipitation over 13 years (V6 was tested for historical context). The interpolated data from 25 rain gauges were compared with both versions of TRMM. The V7 product tended to produce a slight increase in PC (proportion correct). V7 also showed a slight increase in the correlation coefficient (CC) and a significant increase in the H (hit rate) and CSI (critical success) indexes. However, the upgraded version shows an undesirable increase in the false alarm ratio. When the rainfall volumes were compared, V6 clearly underestimated the total rainfall over the entire period, but the V7 product slightly overestimated the cumulative volume (11%) which still represented a more reliable estimate than from V6. Furthermore, the main improvement in V7 was a large increase in the quantitative recognition of extreme precipitation events: V6 detected only 1% of the daily rainfalls above 60 mm, whereas V7 detected 57% of the events.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12665-013-2562-1", "year": 2014, "title": "Geomorphology and the controls of geohydrology on waterlogging in Gangetic Plains, North Bihar, India", "abstract": "Waterlogging is a complex phenomenon, the severity of which depends on a number of natural as well as anthropogenic factors. The present study pertains to the evaluation of control exerted by various factors, viz geomorphology, relief, groundwater fluctuation, rainfall, catchment area and canalroad network density, on waterlogging in the north Bihar region of Gangetic Plains. Satellite images IRS P6 LISS III acquired in the years 2005 and 2006 were used to map temporal variability in surface waterlogging which revealed a reduction of 52 % in the waterlogging area during the pre-monsoon. The seasonal groundwater fluctuation was examined using 20052006 pre- and post-monsoon water level data. It clearly indicated that a large portion of the area was also under highly critical groundwater level occurring at a depth of less than 1 m belowground surface during the post-monsoon periods. The percentage of waterlogged area per square kilometer in each geomorphological unit clearly depicts that the Kosi megafan (Lower), because of a high density of paleochannels, comprises the highest post-monsoon waterlogged area. The Tropical Rainfall Measuring Mission (TRMM) data were analyzed for the period 19982009 to examine the spatial variability of rainfall over the entire catchment during the monsoon period. The high incidence of post-monsoon surface waterlogging delineated through satellite data and high average rainfall (>1,100 mm) in the same area indicates a positive relationship between rainfall and surface waterlogging. Waterlogging is more prominent in the lower relief zones, but anomalous relative rise in waterlogging within 4050 m of relief zone was attributed to anthropogenic factors primarily related to the development of canal network.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.GLOPLACHA.2011.04.005", "year": 2011, "title": "A short note on linkage of climatic records between a river valley and the upper timberline in the Sygera Mountains, southeastern Tibetan Plateau", "abstract": "Tree-ring data from timberlines have been widely used to reconstruct past temperature variability. High-quality reconstructions depend on successful calibrations in which tree-ring records are compared with instrumental observations of climatic factors to establish quantitative relationships between tree growth and climate. Climatic data used in the calibrations are mostly from nearby meteorological stations, located generally in the valleys near human settlements of mountainous areas, regardless of whether climatic records at low elevations are representative for the upper timberline. In order to better understand the characteristics of the alpine environment at the upper timberline of blackseed juniper (Juniperus saltuaria) in the eastern side of the Sygera Mountains, southeastern Tibetan Plateau, an automatic weather station was established. We found that the variation in the daily/5-day/10-day/monthly mean temperatures and sums of precipitation on the valley bottom (3000ma.s.l.) as well as the daily/seasonal sums of precipitation from the TRMM (Tropical Rainfall Measuring Mission) are highly correlated with the measurements at the upper timberline (4400ma.s.l.). Thus, the variations of the valley bottom temperature and precipitation records are confident indicators of the conditions at the upper timberline on the southeastern Tibetan Plateau and hence can be used for the calibration in the dendroclimatic reconstructions based on timberline tree-ring data. For 5-day mean temperature pooled by individual months, the R2 values of the regression models>0.60 between the valley bottom and timberline in FebruaryAugust and October, and <0.40 in December. For 5-day total precipitation, the R2 values>0.60 in MarchJuly and OctoberDecember, and <0.40 in January, February, August and September. This study represents a small step towards fixing problems regarding to dendroclimatic calibrations.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1623/HYSJ.53.6.1137", "year": 2008, "title": "Evaluation of five satellite products for estimation of rainfall over Uganda / Evaluation de cinq produits satellitaires pour l'estimation des precipitations en Ouganda", "abstract": "Five satellite-based rainfall estimation algorithms (TRMM 3B42, CMORPH, TAMSAT, RFE 2.0 and PERSIANN) are assessed against historical monthly rainfall statistics from raingauges within four regions of Uganda. Results are discussed in terms of the accuracy of the products, the effect of climate variability, and differences between products. Products are able to reasonably reflect seasonal patterns in rainfall, and also the spatial patterns in rainfall between regions. Patterns in the occurrence of rainfall are better reflected than patterns in rainfall amounts. There is significant scope for improving the estimation of amounts by calibration to the raingauge data. TRMM 3B42, CMORPH and TAMSAT show most promise in this application followed by RFE 2.0 and the PERSIANN system. However, the relative performance of the products depends on what aspects of the rainfall regime are being considered. Differences between the products are large and the use of more than one product for any application is recommended.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.PCE.2017.02.009", "year": 2017, "title": "Evaluation of satellite and simulated rainfall products for hydrological applications in the Notwane catchment, Botswana", "abstract": "In semi-arid catchments, hydrological modeling, water resources planning and management are hampered by insufficient spatial rainfall data which is usually derived from limited rain gauge networks. Satellite products are potential candidates to augment the limited spatial rainfall data in these areas. In this paper, the utility of the Tropical Rainfall Measuring Mission (TRMM) product (3B42 v7) is evaluated using data from the Notwane catchment in Botswana. In addition, rainfall simulations obtained from a multi-site stochastic rainfall model based on the generalised linear models (GLMs) were used as additional spatial rainfall estimates. These rainfall products were compared to the observed rainfall data obtained from six (6) rainfall stations available in the catchment for the period 19982012. The results show that in general the two approaches produce reasonable spatial rainfall estimates. However, the TRMM products provided better spatial rainfall estimates compared to the GLM rainfall outputs on an average, as more than 90% of the monthly rainfall variations were explained by the TRMM compared to 80% from the GLMs. However, there is still uncertainty associated mainly with limited rainfall stations, and the inability of the two products to capture unusually high rainfall values in the data sets. Despite this observation, rainfall indices computed to further assess the daily rainfall products (i.e. rainfall occurrence and amounts, length of dry spells) were adequately represented by the TRMM data compared to the GLMs. Performance from the GLMs is expected to improve with addition of further rainfall predictors. A combination of these rainfall products allows for reasonable spatial rainfall estimates and temporal (short term future) rainfall simulations from the TRMM and GLMs, respectively. The results have significant implications on water resources planning and management in the catchment which has, for the past three years, been experiencing prolonged droughts as shown by the drying of Gaborone dam (currently at a record low of 1.6% full), which is the main source of water supply to the city of Gaborone and neighbouring townships in Botswana.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSRES.2017.09.007", "year": 2018, "title": "Characteristics of different convective parameterization schemes on the simulation of intensity and track of severe extratropical cyclones over North Atlantic", "abstract": "The role of the convective parameterization schemes (CPSs) in the ARW-WRF (WRF) mesoscale model is ex-\namined for extratropical cyclones (ETCs) over the North Atlantic Ocean. The simulation of very severe winter\nstorms such as Xynthia (2010) and Gong (2013) are considered in this study. Most popular CPSs within WRF\nmodel, along with Yonsei University (YSU) planetary boundary layer (PBL) and WSM6 microphysical para-\nmeterization schemes are incorporated for the model experiments. For each storm, four numerical experiments\nwere carried out using New Kain Fritsch (NKF), Betts-Miller-Janjic (BMJ), Grell 3D Ensemble (Gr3D) and no\nconvection scheme (NCS) respectively. The prime objectives of these experiments were to recognize the best CPS\nthat can forecast the intensity, track, and landfall over the Iberian Peninsula in advance of two days. The WRF\nmodel results such as central sea level pressure (CSLP), wind field, moisture flux convergence, geopotential\nheight, jet stream, track and precipitation have shown sensitivity CPSs. The 48-hour lead simulations with BMJ\nschemes produce the best simulations both regarding ETCs intensity and track than Gr3D and NKF schemes. The\naverage MAE and RMSE of intensities are least that (6.5 hPa in CSLP and 3.4 ms 1 in the 10-m wind) found in\nBMJ scheme. The MAE and RMSE for and intensity and track error have revealed that NCS produces large errors\nthan other CPSs experiments. However, for track simulation of these ETCs, at 72-, 48- and 24-hour means track\nerrors were 440, 390 and 158 km respectively. In brevity, BMJ and Gr3D schemes can be used for short and\nmedium range predictions of the ETCs over North Atlantic. For the evaluation of precipitation distributions using\nGr3D scheme are good agreement with TRMM satellite than other CPSs.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1007/978-981-16-2904-4_8", "year": 2022, "title": "Hydrologic Assessment of the Uncertainty of Six Remote Sensing Precipitation Estimates Driven by a Distributed Hydrologic Model in the Blue Nile Basin", "abstract": "Because of the sparseness of the ground monitoring network, precipitation estimations based on satellite products (PESPs) are currently requisite tools for hydrological simulation research and applications. The evaluation of six global high-resolution PESPs (TRMM 3B42V7, GPGP-1DD, TRMM 3B42RT, CMORPH-V1.0, PERSIANN, and PERSIANN-CDR) is the ultimate purpose of this research. Additionally, the distributed Hydrological River Basin Environmental Assessment Model (Hydro-BEAM) is used to investigate their potential effects in streamflow predictions over the Blue Nile basin (BNB) during the period 2001 to 2007. The correctness of the studied PESPs is assessed by applying categorical criteria to appraise their performances in estimating and reproducing precipitation amounts, while statistical indicators are utilized to determine their rain detection capabilities. Our findings reveal that TRMM 3B42V7 outperforms the remaining product in both the estimation of precipitation and the hydrological simulation, as reflected in highest NSE and R2 values ranges from 0.85 to 0.94. Generally, the TRMM 3B42V7 precipitation product exhibits tremendous potential as a substitute for precipitation estimates in the BNB, which will provide powerful forcing input data for distributed hydrological models. Overall, this study will hopefully provide a better comprehension of the usefulness and uncertainties of various PESPs in streamflow simulations, particularly in this region.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JAG.2018.02.010", "year": 2018, "title": "Seasonality of vegetation types of South America depicted by moderate resolution imaging spectroradiometer (MODIS) time series", "abstract": "The development, implementation and enforcement of policies involving the rational use of the land and the conservation of natural resources depend on an adequate characterization and understanding of the land cover, including its dynamics. This paper presents an approach for monitoring vegetation dynamics using high-quality time series of MODIS surface reflectance data by generating fraction images using Linear Spectral Mixing Model (LSMM) over South America continent. The approach uses physically-based fraction images, which highlight target information and reduce data dimensionality. Further dimensionality was also reduced by using the vegetation fraction images as input to a Principal Component Analysis (PCA). The RGB composite of the first three PCA components, accounting for 92.9% of the dataset variability, showed good agreement with the main ecological regions of South America continent. The analysis of 21 temporal profiles of vegetation fraction values and precipitation data over South America showed the ability of vegetation fractions to represent phenological cycles over a variety of environments. Comparisons between vegetation fractions and precipitation data indicated the close relationship between water availability and leaf mass/chlorophyll content for several vegetation types. In addition, phenological changes and disturbance resulting from anthropogenic pressure were identified, particularly those associated with agricultural practices and forest removal. Therefore the proposed method supports the management of natural and non-natural ecosystems, and can contribute to the understanding of key conservation issues in South America, including deforestation, disturbance and fire occurrence and management.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/IJGI7070275", "year": 2018, "title": "Temporal Variations and Associated Remotely Sensed Environmental Variables of Dengue Fever in Chitwan District, Nepal", "abstract": "Dengue fever is one of the leading public health problems of tropical and subtropical countries across the world. Transmission dynamics of dengue fever is largely affected by meteorological and environmental factors, and its temporal pattern generally peaks in hot-wet periods of the year. Despite this continuously growing problem, the temporal dynamics of dengue fever and associated potential environmental risk factors are not documented in Nepal. The aim of this study was to fill this research gap by utilizing epidemiological and earth observation data in Chitwan district, one of the frequent dengue outbreak areas of Nepal. We used laboratory confirmed monthly dengue cases as a dependent variable and a set of remotely sensed meteorological and environmental variables as explanatory factors to describe their temporal relationship. Descriptive statistics, cross correlation analysis, and the Poisson generalized additive model were used for this purpose. Results revealed that dengue fever is significantly associated with satellite estimated precipitation, normalized difference vegetation index (NDVI), and enhanced vegetation index (EVI) synchronously and with different lag periods. However, the associations were weak and insignificant with immediate daytime land surface temperature (dLST) and nighttime land surface temperature (nLST), but were significant after 45 months. Conclusively, the selected Poisson generalized additive model based on the precipitation, dLST, and NDVI explained the largest variation in monthly distribution of dengue fever with minimum Akaikes Information Criterion (AIC) and maximum R-squared. The best fit model further significantly improved after including delayed effects in the model. The predicted cases were reasonably accurate based on the comparison of 10-fold cross validation and observed cases. The lagged association found in this study could be useful for the development of remote sensing-based early warning forecasts of dengue fever.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/W9070459", "year": 2017, "title": "An assessment of mean areal precipitation methods on simulated stream flow: a SWAT model performance assessment", "abstract": "Accurate mean areal precipitation (MAP) estimates are essential input forcings for\nhydrologic models. However, the selection of the most accurate method to estimate MAP can\nbe daunting because there are numerous methods to choose from (e.g., proximate gauge, direct\nweighted average, surface-fitting, and remotely sensed methods). Multiple methods (n = 19) were\nused to estimate MAP with precipitation data from 11 distributed monitoring sites, and 4 remotely\nsensed data sets. Each method was validated against the hydrologic model simulated stream flow\nusing the Soil and Water Assessment Tool (SWAT). SWAT was validated using a split-site method and\nthe observed stream flow data from five nested-scale gauging sites in a mixed-land-use watershed\nof the central USA. Cross-validation results showed the error associated with surface-fitting and\nremotely sensed methods ranging from 4.5% to 5.1%, and 9.8% to 14.7%, respectively. Split-site\nvalidation results showed the percent bias (PBIAS) values that ranged from 4.5% to 160%. Second\norder polynomial functions especially overestimated precipitation and subsequent stream flow\nsimulations (PBIAS = 160) in the headwaters. The results indicated that using an inverse-distance\nweighted, linear polynomial interpolation or multiquadric function method to estimate MAP may\nimprove SWAT model simulations. Collectively, the results highlight the importance of spatially\ndistributed observed hydroclimate data for precipitation and subsequent steam flow estimations.\nThe MAP methods demonstrated in the current work can be used to reduce hydrologic model\nuncertainty caused by watershed physiographic differences.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00704-015-1680-Y", "year": 2017, "title": "A study on the role of land-atmosphere coupling on the south Asian monsoon climate variability using a regional climate model", "abstract": "Land-atmosphere coupling over the south Asian monsoon region is examined using a regional climate model. For this purpose, the Weather Research and Forecasting (WRF) model with a resolution of 45 km was used. In the control experiment (CTL), the model was integrated from the year 2000 to 2011 and allowed the soil moisture interaction with the atmosphere using a coupled land surface model. In the second experiment (CSM), the soil moisture evolution at each time step was replaced with the climatology of soil moisture taken from the control run. The results reveal that land-atmosphere coupling plays a critical role in influencing the south Asian monsoon climate variability. Soil moisture is found to have stronger impacts on daily maximum temperature compared to minimum temperature. Soil moisture also makes a significant contribution to monsoon rainfall variability over the monsoon region. The coupling strength for large-scale rainfall is found to be higher compared to that of cumulus rainfall. Soil moisture is found more strongly coupled to sensible heat flux over most of the monsoon region.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00704-016-1894-7", "year": 2017, "title": "Impact of single-point GPS integrated water vapor estimates on short-range WRF model forecasts over southern India", "abstract": "Specifying physically consistent and accurate initial conditions is one of the major challenges of numerical weather prediction (NWP) models. In this study, ground-based global positioning system (GPS) integrated water vapor (IWV) measurements available from the International Global Navigation Satellite Systems (GNSS) Service (IGS) station in Bangalore, India, are used to assess the impact of GPS data on NWP model forecasts over southern India. Two experiments are performed with and without assimilation of GPS-retrieved IWV observations during the Indian winter monsoon period (NovemberDecember, 2012) using a four-dimensional variational (4D-Var) data assimilation method. Assimilation of GPS data improved the model IWV analysis as well as the subsequent forecasts. There is a positive impact of 10 % over Bangalore and nearby regions. The Weather Research and Forecasting (WRF) model-predicted 24-h surface temperature forecasts have also improved when compared with observations. Small but significant improvements were found in the rainfall forecasts compared to control experiments.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.GEOMORPH.2017.01.003", "year": 2017, "title": "Assessment of landslide hazards induced by extreme rainfall event in Jammu and Kashmir Himalaya, northwest India", "abstract": "In the Indian Himalayan region (IHR), landslide-driven hazards have intensified over the past several decades primarily caused by the occurrence of heavy and extreme rainfall. However, little attention has been given to determining the cause of events triggered during pre- and post-Indian Summer Monsoon (ISM) seasons. In the present research, detailed geological, meteorological, and remote sensing investigations have been carried out on an extreme rainfall landslide event that occurred in Sadal village, Udhampur district, Jammu and Kashmir Himalaya, during September 2014. Toward the receding phase of the ISM (i.e., in the month of September 2014), an unusual rainfall event of ~ 488.2 mm rainfall in 24 h took place in Jammu and Kashmir Himalaya in contrast to the normal rainfall occurrence. Geological investigations suggest that a planar weakness in the affected region is caused by bedding planes that consist of an alternate sequence of hard, compact sandstone and weak claystone. During this extreme rainfall event, the Sadal village was completely buried under the rock slides, as failure occurred along the planar weakness that dips toward the valley slope. Rainfall data analysis from the Tropical Rainfall Measuring Mission (TRMM) for the preceding years homogeneous time series (JulySeptember) indicates that the years 2005, 2009, 2011, 2012, and 2014 (i.e., closely spaced and clustering heavy rainfall events) received heavy rainfalls during the withdrawal of the ISM; whereas the heaviest rainfall was received in the years 2003 and 2013 at the onset of the ISM in the study region. This suggests that no characteristic cyclicity exists for extreme rainfall events. However, we observe that either toward the onset of the ISM or its retreat, the extreme rainfall facilitates landslides, rockfall, and slope failures in northwestern Himalaya. The spatiotemporal distribution of landslides caused by extreme rainfall events suggests its confinement toward the windward side of the Himalayan front.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-17-615-2017", "year": 2017, "title": "Stratospheric tropical warming event and its impact on the polar and tropical troposphere", "abstract": "Abstract. Stratospheretroposphere coupling is investigated in relation to middle atmospheric subtropical jet (MASTJ) variations in boreal winter. An exceptional strengthening of the MASTJ occurred in association with a sudden equatorward shift of the stratospheric polar night jet (PNJ) in early December 2011. This abrupt transformation of the MASTJ and PNJ had no apparent relation to the upward propagation of planetary waves from the troposphere. The impact of this stratospheric event penetrated into the troposphere in two regions: in the northern polar region and the tropics. Due to the strong MASTJ, planetary waves at higher latitudes were deflected and trapped in the northern polar region. Trapping of the planetary waves resulted in amplification of zonal wave number 1 component, which appeared in the troposphere as the development of a trough over the Atlantic sector and a ridge over the Eurasian sector. A strong MASTJ also suppressed the equatorward propagation of planetary waves, which resulted in weaker tropical stratospheric upwelling and produced anomalous warming in the tropical stratosphere. In the tropical tropopause layer (TTL), however, sublimation of ice clouds kept the temperature change minor. In the troposphere, an abrupt termination of a MaddenJulian Oscillation (MJO) event occurred following the static stability increase in the TTL. This termination suggests that the stratospheric event affected the convective episode in the troposphere.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ISPRSARCHIVES-XL-8-399-2014", "year": 2014, "title": "Satellite-based estimation and validation of monthly rainfall distribution over Upper Ganga river basin", "abstract": "Abstract. Water is one of the most precious natural resources for all living flora and fauna. 97.5% of water on the Earth is sea water, the remaining 2.5 % is fresh water of which slightly over two thirds is frozen in glaciers and polar ice caps. The unfrozen fresh water is mainly found as groundwater, with only a small fraction present above ground or in the air. Since one of the main source of water is rainfall. Therefore, proper information on rainfall and its variability in space and time is required for better watershed planning and management and other applications. In Himalayan basin, the rain gauge network is relatively sparse with uneven distribution. Hence, there is lack of proper information on rainfall patterns of this region. The main advantage of satellite derived rainfall estimation over rain gauge derived rain data is that these provide homogenous spatio-temporal rainfall information over a large area e.g. Upper Ganga river basin region. Therefore, a better understanding of the rainfall patterns of this region is required for better disaster mitigation. The objectives of this study are to evaluate the reliability of Tropical Rainfall Measuring Mission (TRMM) 3B43 V7 derived high resolution satellite product to study the rainfall distribution over the Upper Ganga river basin. TRMM 3B43 V7 derived monthly rainfall data is analyzed and the monthly rainfall product is validated and correlated with IMD (Indian Meteorological Department) gauge station's rainfall data. The monthly rainfall data of 15 years i.e. from 1998 to 2012 is used in the study. Statistical indices can be used to evaluate, compare and validate satellite rainfall data with respect to gauge rainfall data. Statistical indices used in this study are Correlation Coefficient (r), Mean Square Error (MSE), Root Mean Square Error (RMSE), and Average Percentage Error (Avg. % Error). Most of the rainfall in the study area occurs in the months of June, July, August, September and October. The isohyets were prepared using gauge rainfall data and are matched with the spatially distributed rainfall surface prepared from TRMM satellite data for all the months of the rainy season of the study area. Kriging spatial interpolation method was used to generate the spatially distributed rainfall surface. From the results it was observe d that they matched fairly well with each other showing high spatial correlation. The monthly rainfall result showed that TRMM data is underestimated with low accuracy, though TRMM data and rain gauge data have positive correlation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JHYDROL.2016.05.026", "year": 2016, "title": "Testing the skill of numerical hydraulic modeling to simulate spatiotemporal flooding patterns in the Logone floodplain, Cameroon", "abstract": "Recent innovations in hydraulic modeling have enabled global simulation of rivers, including simulation of their coupled wetlands and floodplains. Accurate simulations of floodplains using these approaches may imply tremendous advances in global hydrologic studies and in biogeochemical cycling. One such innovation is to explicitly treat sub-grid channels within two-dimensional models, given only remotely sensed data in areas with limited data availability. However, predicting inundated area in floodplains using a sub-grid model has not been rigorously validated. In this study, we applied the LISFLOOD-FP hydraulic model using a sub-grid channel parameterization to simulate inundation dynamics on the Logone River floodplain, in northern Cameroon, from 2001 to 2007. Our goal was to determine whether floodplain dynamics could be simulated with sufficient accuracy to understand human and natural contributions to current and future inundation patterns. Model inputs in this data-sparse region include in situ river discharge, satellite-derived rainfall, and the shuttle radar topography mission (SRTM) floodplain elevation. We found that the model accurately simulated total floodplain inundation, with a Pearson correlation coefficient greater than 0.9, and RMSE less than 700km2, compared to peak inundation greater than 6000km2. Predicted discharge downstream of the floodplain matched measurements (NashSutcliffe efficiency of 0.81), and indicated that net flow from the channel to the floodplain was modeled accurately. However, the spatial pattern of inundation was not well simulated, apparently due to uncertainties in SRTM elevations. We evaluated model results at 250, 500 and 1000-m spatial resolutions, and found that results are insensitive to spatial resolution. We also compared the model output against results from a run of LISFLOOD-FP in which the sub-grid channel parameterization was disabled, finding that the sub-grid parameterization simulated more realistic dynamics. These results suggest that analysis of global inundation is feasible using a sub-grid model, but that spatial patterns at sub-kilometer resolutions still need to be adequately predicted.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S12040-015-0622-5", "year": 2015, "title": "Numerical simulation of an intense precipitation event over Rudraprayag in the central Himalayas during 1314 September 2012", "abstract": "A recent heavy precipitation event on 13 September 2012 and the associated landslide on 14 September 2012 is one of the most severe calamities that occurred over the Rudraprayag region in Uttarakhand, India. This heavy precipitation event is also emblematic of the natural hazards occuring in the Himalayan region. Study objectives are to present dynamical fields associated with this event, and understand the processes related to the severe storm event, using the Weather Research and Forecasting (WRF ver 3.4) model. A triple-nested WRF model is configured over the Uttarakhand region centered over Ukhimath (3030N; 79 15E), where the heavy precipitation event is reported. Model simulation of the intense storm on 13 September 2012 is with parameterized and then with explicit convection are examined for the 3 km grid spacing domain. The event was better simulated without the consideration of convection parameterization for the innermost domain. The role of steep orography forcings is notable in rapid dynamical lifting as revealed by the positive vorticity and high reflectivity values and the intensification of the monsoonal storm. Incursion of moist air, in the lower levels, converges at the foothills of the mountains and rise along the orography to form the updraft zone of the storm. Such rapid unstable ascent leads to deep convection and increases the condensation rate of the water vapour forming clouds at a swift rate. This culminates into high intensity precipitation which leads to high amount of surface runoff over regions of susceptible geomorphology causing the landslide. Even for this intense and potentially unsual rainfall event, the processes involved appear to be the classic enhanced convective activity by orographic lifting of the moist air, as an important driver of the event.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12517-013-1094-Z", "year": 2014, "title": "Evaluating factors responsible for contrasting signature of wasteland development in northern and southern Ganga Plains (Bihar State, India) with focus on waterlogging", "abstract": "The present study provides assessment of wasteland development in Bihar State based on satellite data. Wasteland covers 6.90 % (6,501 km2) of the state area and exhibits dominance of waterlogged areas in North Bihar (25.28 %) and scrubland (26.61 %) in South Bihar. The waterlogged areas in the state are dominantly associated with northern Bihar plains (94 %) with minor development (6 %) in southern Bihar plains. Such unequal distribution of waterlogged land areas in northern and southern Bihar plains is largely governed by high cumulative discharge generated in the large catchment area in Himalayan mountain ranges in the upland areas of northern Bihar plains in contrast to low cumulative discharge generated within small catchments in the Chota Nagpur Plateau in the southern Bihar plains. It is evaluated that the relief and groundwater level define the primary controlling factors, whereas rainfall, watershed area, and upland/plain ratio exert secondary control. Lower relief areas with high rainfall exhibit high soil moisture thereby inducing conditions of waterlogging. The study signifies the potential of satellite image-based evaluation of waterlogging through the use of Digital Elevation Model, Tropical Rainfall Measuring Mission-based rainfall measurement, and temporal waterlogging assessment together with other terrain parameters for conceptual understanding of waterlogging in northern Bihar plains.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1080/02723646.2014.893476", "year": 2014, "title": "Conditions associated with large rain-field areas for tropical cyclones landfalling over Florida", "abstract": "To adequately warn the public about the potential for heavy rainfall, it is important to understand the conditions associated with large rain fields as tropical cyclones (TCs) move over land. This study examines rain-field areas during 29 landfalls over Florida utilizing data from the Tropical Rainfall Measuring Missions 3B42 product. A GIS was used to calculate the areas of regions delineated by 5 mm h1 rain rates occurring within 48 h pre- or post-landfall. Thirteen conditions were evaluated, including intensity, motion, vertical wind shear, cause of demise, month, and time of day. After dividing observations into groups for each condition, MannWhitney U and KruskalWallis tests determined that statistically significant differences existed among the groups for 11 conditions. The largest rain fields belonged to TCs that occurred in October or November, followed by those that were hurricanes and/or were intensifying at landfall. TCs nearing the end of an extratropical transition as well as those observed at 1100 Eastern Daylight Time also had relatively large areas of moderate-to-high rain rates. TCs meeting these conditions should be monitored closely as they move towards and over Florida due to their potential for widespread moderate-to-heavy rainfall, which may begin prior to the arrival of the fastest winds.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.3390/IJGI3041372", "year": 2014, "title": "Use of the NASA Giovanni Data System for Geospatial Public Health Research: Example of Weather-Influenza Connection", "abstract": "The NASA Giovanni data analysis system has been recognized as a useful tool to access and analyze many different types of remote sensing data. The variety of environmental data types has allowed the use of Giovanni for different application areas, such as agriculture, hydrology, and air quality research. The use of Giovanni for researching connections between public health issues and Earths environment and climate, potentially exacerbated by anthropogenic influence, has been increasingly demonstrated. In this communication, the pertinence of several different data parameters to public health will be described. This communication also provides a case study of the use of remote sensing data from Giovanni in assessing the associations between seasonal influenza and meteorological parameters. In this study, logistic regression was employed with precipitation, temperature and specific humidity as predictors. Specific humidity was found to be associated (p < 0.05) with influenza activity in both temperate and tropical climate. In the two temperate locations studied, specific humidity was negatively correlated with influenza; conversely, in the three tropical locations, specific humidity was positively correlated with influenza. Influenza prediction using the regression models showed good agreement with the observed data (correlation coefficient of 0.50.83).", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S10346-013-0422-4", "year": 2013, "title": "Tumbi Landslide, Papua New Guinea: rainfall induced?", "abstract": "On 24 January 2012, a fatal landslide with an estimated volume of 3 Mm3 hit villagers and infrastructure in the Tagali Valley, Southern Highlands Province, Papua New Guinea (PNG). Although a moderate event by PNG standards, the associated human casualties and infrastructure destruction give a human as well as a scientific need to review the potential causes for the event. PNG experiences numerous landslides annually, most of which are trigged either by rainfall events or seismic activity. Here, we review the short-term rainfall patterns leading up to the slope failure at Tumbi Quarry and compare the rainfall accumulations obtained over durations of 30, 60 and 90 days prior to the landslide, with comparable rainfall accumulations obtained for other failures observed in PNG over a 12-year period. Additionally, a review of long-term rainfall over a period of 6 months prior to the failure is completed as well as an assessment of seismic activity. Based on our analysis, we believe a seismic trigger to be very unlikely, while the increase in rainfall in the 2 weeks prior to the failure in conjunction with a high-intensity rainfall event at the end of October 2011 could have had a greater influence in enhancing rather than restraining slope failure. This, in addition to natural denudational processes, geological structure and the anthropogenic activity in the vicinity of the landslide, could all have served to affect slope stability.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S11356-011-0506-4", "year": 2011, "title": "Anomalous low tropospheric column ozone over Eastern India during the severe drought event of monsoon 2002: a case study", "abstract": "The present study is an attempt to examine some of the probable causes of the unusually low tropospheric column ozone observed over eastern India during the exceptional drought event in July 2002.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/W5020698", "year": 2013, "title": "Remote Sensing Analysis of Lake Dynamics in Semi-Arid Regions: Implication for Water Resource Management. Lake Manyara, East African Rift, Northern Tanzania", "abstract": "We show here that a remote sensing (RS) approach is a cost-efficient and accurate method to study water resource dynamics in semi-arid areas. We use a MODIS surface reflectance dataset and a Modified Normalized Difference Water Index (MNDWI) to map the variability of Lake Manyaras water surface area using a histogram segmentation technique. The results indicate that Lake Manyaras water surface coverage has been decreasing from 520.25 km2 to 30.5 km2 in 2000 and 2011 respectively. We observe that the lake water surface and the lake water balance displayed a similar pattern from 2006 to 2009, probably initiated by heavy rainfall and low temperature in 2006. Lake water surface area appears to have an inverse relationship with MODIS evapotranspiration (ET) and MODIS land surface temperature (LST). We imply that recent fluctuations of Lake Manyaras surface water area are a direct consequence of global and regional climate fluctuations. We therefore conclude that, by means of RS it is possible to provide timely and up-to-date water resource information to managers and hence enable optimized and operational decisions for sustainable management and conservation. We suggest that the method employed in this research should be applied to monitor water resource dynamics provided that remotely sensed datasets are available.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSE.2012.02.022", "year": 2012, "title": "Near real-time disturbance detection using satellite image time series", "abstract": "Near real-time monitoring of ecosystem disturbances is critical for rapidly assessing and addressing impacts on carbon dynamics, biodiversity, and socio-ecological processes. Satellite remote sensing enables cost-effective and accurate monitoring at frequent time steps over large areas. Yet, generic methods to detect disturbances within newly captured satellite images are lacking. We propose a multi-purpose time-series-based disturbance detection approach that identifies and models stable historical variation to enable change detection within newly acquired data. Satellite image time series of vegetation greenness provide a global record of terrestrial vegetation productivity over the past decades. Here, we assess and demonstrate the method by applying it to (1) simulated time series of vegetation greenness data from satellite data, (2) real-world satellite greenness image time series between February 2000 and July 2011 covering Somalia to detect drought-related vegetation disturbances. First, simulation results illustrate that disturbances are successfully detected in near real-time while being robust to seasonality and noise. Second, major drought-related disturbance corresponding with most drought-stressed regions in Somalia are detected from mid-2010 onwards. The method can analyse in-situ or satellite data time series of biophysical indicators from local to global scale since it is fast, does not depend on thresholds and does not require time series gap filling. While the data and methods used are appropriate for proof-of-concept development of global scale disturbance monitoring, specific applications (e.g., drought or deforestation monitoring) mandate integration within an operational monitoring framework (e.g., http://www.fews.net/).", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1111/J.1752-1688.2011.00604.X", "year": 2012, "title": "Validation of Satellite Precipitation Adjustment Methodology From Seven Basins in the Continental United States1", "abstract": "Tobin, Kenneth J. and Marvin E. Bennett, 2012. Validation of Satellite Precipitation Adjustment Methodology From Seven Basins in the Continental United States. Journal of the American Water Resources Association (JAWRA) 48(2): 221-234. DOI: 10.1111/j.1752-1688.2011.00604.x Abstract: The precipitation science community has expressed concern regarding the ability of satellite-based precipitation products to accurately capture rainfall values over land. There has been some work that has focused on addressing the deficiencies of satellite precipitation products, particularly on the adjustment of bias. This article outlines a methodology that adjusts satellite products utilizing ground-based precipitation data. The approach is not a simple bias adjustment, but is a three-step process that transforms a satellite product based on a ground-based precipitation product (NEXRAD-derived Multisensor Precipitation Estimator [MPE] product or rain-gauge data). The developed methodology was successfully applied to seven moderate-to-large sized watersheds from continental United States (CONUS) and northern Mexico over a spectrum of climatic regimes ranging from dry to humid settings. Methodology validation is based on comparison of observed and simulated streamflow generated with SWAT (Soil and Water Assessment Tool) model using unadjusted and adjusted precipitation products as input. Streamflow comparison is based on mass balance error and Nash-Sutcliffe efficiency coefficient. Finally, the contribution of how adjustment to correct misses, false alarms, and bias impacts adjusted datasets and the potential impact that the adjustment methodology can have on hydrological applications such as water resource monitoring and flood prediction are explored.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00703-012-0189-5", "year": 2012, "title": "Intra-seasonal variability in Oceansat-2 scatterometer sea-surface winds over the Indian summer monsoon region", "abstract": "In September 2009, the Indian Space Research Organisation launched a Ku-band microwave scatterometer (OSCAT) onboard the polar orbiting satellite Oceansat-2. In this article, the capabilities of the newly available OSCAT sea-surface winds are demonstrated by studying the monsoon intra-seasonal variabilities during the 2010 summer monsoon season. A preliminary validation of OSCAT surface winds with European Centre for Medium Range Weather Forecasting (ECMWF) analysis surface winds carried out during June to August 2010 suggests that the quality of the OSCAT winds are able to meet the mission specifications. The observed mean monthly features of the Indian summer monsoon in July and August 2010 from OSCAT match well with those of ECMWF reanalysis winds. The OSCAT winds capture the known characteristics of the Indian summer monsoon, such as the northward propagation of a low level jet, and its preferred locations during active and break monsoon conditions, reasonably well. The Morlet wavelet transform is used for time series analysis. The OSCAT measured sea-surface winds were found to possess two dominant modes of variability during the 2010 monsoon season: one with a periodicity between 32 and 64 days, and another with a periodicity between 8 and 16 days. Rainfall activity over the Indian summer monsoon region is closely associated with the phases of the two above-mentioned dominant intra-seasonal variabilities. This study demonstrates that the OSCAT winds can be used very well and with confidence for meteorological studies.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2012JD017716", "year": 2012, "title": "Variabilities in ozone at a semi-urban site in the Indo-Gangetic Plain region: Association with the meteorology and regional processes", "abstract": "The Indo-Gangetic Plain (IGP) region is one of the most densely populated regions in the World, but ground-based observations of air pollutants are highly limited in this region. Here, surface ozone observations made during March 2009June 2011 at a semi-urban site (Pantnagar; 29.0N, 79.5E, 231 m amsl) in the IGP region are presented. Ozone mixing ratios show a daytime photochemical buildup with ozone levels sometimes as high as 100 ppbv. Seasonal variation in 24-h average ozone shows a distinct spring maximum (39.3 18.9 ppbv in May) while daytime (11301630 h) average ozone shows an additional peak during autumn (48.7 13.8 ppbv in November). The daytime, but not daily average, observed ozone seasonality is in agreement with the space-borne observations of OMI tropospheric column NO2, TES CO (681 hPa), surface ozone observations at a nearby high altitude site (Nainital) in the central Himalayas and to an extent with results from a global chemistry transport model (MATCH-MPIC). It is suggested that spring and autumn ozone maximum are mainly due to photochemistry, involving local pollutants and small-scale dynamical processes. Biomass burning activity over the northern Indian region could act as an additional source of ozone precursors during spring. The seasonal ozone photochemical buildup is estimated to be 3241 ppbv during spring and autumn and 914 ppbv during AugustSeptember. A correlation analysis between ozone levels at Pantnagar and Nainital along with the mixing depth data suggests that emissions and photochemical processes in the IGP region influence the air quality of pristine Himalayan region, particularly during midday hours of spring. The evening rate of change (8.5 ppbv hr1) is higher than the morning rate of change, which is dissimilar to those at other urban or rural sites. Ozone seasonality over the IGP region is different than that over southern India. Results from the MATCH-MPIC model capture observed ozone seasonality but overestimate ozone levels. Model simulated daytime ratios of H2O2/HNO3 are higher and suggesting that this region is in a NOx-limited regime. A chemical box model (NACR Master Mechanism) is used to further corroborate this using a set of sensitivity simulations, and to estimate the integrated net ozone production in a day (72.9 ppbv) at this site.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1080/23249676.2021.1884617", "year": 2021, "title": "Rainfall-runoff simulation using satellite rainfall in a scarce data catchment", "abstract": "This study investigates the performance of TRMM and PERSIANN satellite rainfall data as input in a reliable rainfall-runoff model in order to provide information to the flood early warning for the Voshmgir Dam, Iran. Calibration of both continuous daily rainfall-runoff and an event-based flood was done using HEC-HMS Nelder-Mead (NM) method. Furthermore, simulations based on daily versus 3-hourly TRMM were compared to evaluate the effect of input time-step of rainfall-runoff model. Results show that the deficit and constant loss method is able to successfully predict the observed runoff. In addition, the Green-Ampt method using 3-hourly TRMM data showed a good capability to simulate daily peak discharges. The current study demonstrates the suitability of HEC-HMS for continuous and event-based runoff simulation in a complex watershed. Therefore, this research will have a significant contribution to the future development of water resources planning in this catchment in particular and in other data-scarce catchments.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.RSASE.2021.100589", "year": 2021, "title": "Precipitation estimations based on remote sensing compared with data from weather stations over agricultural region of Argentina pampas", "abstract": "Global patterns of precipitation have changed due to the increase in temperature as a result of climate change. Measuring the amount of precipitation at a given location using surface instruments is relatively simple. However, the great spatial and temporal variability of the intensity, type and occurrence of this phenomenon, makes direct and uniformly calibrated measurements difficult in large regions. Satellite information is an important alternative to describe precipitation events; the Global Precipitation Measurement (GPM) mission estimates precipitation, considering different time periods, with three products Integrated Multi-Satellite Retrievals for GPM (IMERG), in near real time. This study evaluates and quantifies, temporal and spatially, the monthly precipitation estimated by Early (IMERG-E), Late (IMERG-L) and Final (IMERG-F) products compared with data from weather stations located in agricultural areas of the Pampas region in Argentina. Data of precipitation belonging to meteorological stations located at four provinces: Buenos Aires, Cordoba, La Pampa and Santa Fe, for 20142018 periods, were considered. The spatial performance of IMERG was evaluated using statistical coefficients and Taylor diagrams, considering at region, province and stations level. The adjustment of the products increased from IMERG-E to IMERGF, obtaining R2 values between 0.86 and 0.95 and RMSE from 14.2 to 29.3 mm, the best results corresponding to Cordoba and the worst to La Pampa. The performance of GPM products varies temporally; IMERG-F presented a higher correlation coefficient and a lower percent root mean square error in warm than in cold seasons. The results indicate that GPM can effectively capture the amount and patterns of monthly precipitation over the Pampas region of Argentina, which is important for its application to agricultural production and disaster prevention.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S11356-023-27047-5", "year": 2023, "title": "A study on optical properties, classification, and transport of aerosols during the smog period over South Asia using remote sensing", "abstract": "Over the past few years, South Asian region has experienced frequent and thick smog events because of rapid population growth and enhanced anthropogenic activities, particularly in the Indo-Gangetic Plain (IGP). Therefore, the present study investigates aerosol properties such as aerosol optical depth (AOD) (500 nm), Angstrom exponent (AE) (440870 nm), single scattering albedo (SSA), fine-mode fraction (FMF), absorption aerosol optical depth (AAOD), and absorption aerosol exponent (AAE) over selected AERONET sites namely Bhola (20122021), Dhaka (20122021), Jaipur (20112021), Kanpur (20112021), Karachi (20112021), Lahore (20112021), and Pokhara (20112021) in the IGP during the smog period (October, November, and December). Additionally, different aerosol types were categorized using AERONET direct sun (AOD, AE) and inversion products (VSD, SSA, RI, FMF, and ASY). The monthly mean AOD, AE, and FMF varied from 0.33 to 1.07, 0.3 to 1.4, and 0.60.9 m over all selected AERONET sites during the smog period. Moreover, the outcomes revealed the dominance of biomass-burning and urban/ industrial aerosols over Lahore, Karachi, Dhaka, and Bhola during the smog period. Contrary to this, dust and mixed aerosols were abundant over Jaipur and Karachi, respectively. Furthermore, HYSPLIT cluster analysis is used to trace the transmission paths and potential sources of aerosols over selected sites.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.25130/TJPS.V24I6.441", "year": 2019, "title": "Integrating GIS-based and geophysical techniques for groundwater potential assessment in Halabja Said Sadiq sub-basin, Kurdistan, NE Iraq", "abstract": "Groundwater is an important resource in Halabja Said Sadiq sab-basin, Sulaymaniyah district for agricultural and other uses. Continuous dramatic extraction of groundwater from legal and illegal wells led to a severe decline in the water table for the last thirty years. The objectives of this study are to delineate the groundwater productivity zones by combining the geographic information system and geoelectrical survey, which serves to recognize the locations of good groundwater storage and recharge zones. The Halabja Said Sadiq sub-basin has been selected as a case study to delineate the groundwater productivity zones. Four geoelectrical resistivity profiles conducted with electrode spacing 10 m and the length of the profiles is equal to 710 m. Themes such as hydrogeology, land use/land cover, topography, drainage density, soil type, slope, lineaments and rainfall maps are created. The thematic maps made with GIS platform and appropriate weights put to the attributes taking into account the influence on the storage potential of groundwater. The results of geoelectrical profiles revealed that the aquifer thickness is 150 m. Three zones of groundwater potential delineated which are low, moderate and high and cover 33 %, 24 %, and 42 % of the total area respectively. Spatially, the highest zone is located along with the Quaternary deposits which characterized by high lineament density, low slop, and pediment deposition\nThe output of the groundwater potential model is verified by testing the discharge rate of the existing 580 wells. The results are revealed that most of the high yield wells are located within the high groundwater potential zone. Results of such verifications proved that the groundwater productivity areas recognized by GIS (AHP) and geoelectrical techniques are dependable and practical.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.30630/JOIV.7.2.1578", "year": 2023, "title": "Evaluation of the Compatibility of TRMM Satellite Data with Precipitation Observation Data", "abstract": "The availability of hydrological data is one of the challenges associated with developing water infrastructure in different areas. This led to the TRMM (Tropical Precipitation Measurement Mission) design by NASA, which involves using satellite weather monitoring technology to monitor and analyze tropical precipitation in different parts of the world. Therefore, this validation study was conducted to compare TRMM precipitation data with observed precipitation to determine its application as an alternate source of hydrological data. The Kuranji watershed was selected as the study site due to the availability of suitable data. Moreover, the validation analyses applied include the Root Mean Squared Error (RMSE), Nash-Sutcliffe Efficiency (NSE), Coefficient Correlation (R), and Relative Error (RE). These used two calculation forms: one for the uncorrected data and another for the corrected data. The results showed that the best-adjusted data validation from the Gunung Nago station in 2016 was recorded to be RMSE = 62,298, NSE = 0.044, R = 0.902, and RE = 11,328. The closeness of the R-value to one implies that the corrected TRMM data outperforms the uncorrected ones. Therefore, it was generally concluded that the TRMM data matches the observed precipitation data and can be used for hydrological study in the Kuranji watershed", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1038/S41612-023-00367-6", "year": 2023, "title": "Aerosol demasking enhances climate warming over South Asia", "abstract": "Abstract\n \n Anthropogenic aerosols mask the climate warming caused by greenhouse gases (GHGs). In the absence of observational constraints, large uncertainties plague the estimates of this masking effect. Here we used the abrupt reduction in anthropogenic emissions observed during the COVID-19 societal slow-down to characterize the aerosol masking effect over South Asia. During this period, the aerosol loading decreased substantially and our observations reveal that the magnitude of this aerosol demasking corresponds to nearly three-fourths of the CO\n 2\n -induced radiative forcing over South Asia. Concurrent measurements over the northern Indian Ocean unveiled a ~7% increase in the earths surface-reaching solar radiation (surface brightening). Aerosol-induced atmospheric solar heating decreased by ~0.4 K d\n 1\n . Our results reveal that under clear sky conditions, anthropogenic emissions over South Asia lead to nearly 1.4 W m\n 2\n heating at the top of the atmosphere during the period MarchMay. A complete phase-out of todays fossil fuel combustion to zero-emission renewables would result in rapid aerosol demasking, while the GHGs linger on.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/SU15053874", "year": 2023, "title": "Spatial Prediction of Groundwater Withdrawal Potential Using Shallow, Hybrid, and Deep Learning Algorithms in the Toudgha Oasis, Southeast Morocco", "abstract": "Water availability is a key factor in territorial sustainable development. Moreover, groundwater constitutes the survival element of human life and ecosystems in arid oasis areas. Therefore, groundwater potential (GWP) identification represents a crucial step for its management and sustainable development. This study aimed to map the GWP using ten algorithms, i.e., shallow models comprising: multilayer perceptron, k-nearest neighbor, decision tree, and support vector machine algorithms; hybrid models comprising: voting, random forest, adaptive boosting, gradient boosting (GraB), and extreme gradient boosting; and the deep learning neural network. The GWP inventory map was prepared using 884 binary data, with 1 indicating a high GWP and 0 indicating an extremely low GWP. Twenty-three GWP-influencing factors have been classified into numerical data using the frequency ration method. Afterwards, they were selected based on their importance and multi-collinearity tests. The predicted GWP maps show that, on average, only 11% of the total area was predicted as a very high GWP zone and 17% and 51% were estimated as low and very low GWP zones, respectively. The performance analyses demonstrate that the applied algorithms have satisfied the validation standards for both training and validation tests with an average area under curve of 0.89 for the receiver operating characteristic. Furthermore, the models prioritization has selected the GraB model as the outperforming algorithm for GWP mapping. This study provides decision support tools for sustainable development in an oasis area.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/SU15043325", "year": 2023, "title": "GIS-Based Soil Erosion Risk Assessment in the Watersheds of Bukidnon, Philippines Using the RUSLE Model", "abstract": "The sustainability of watersheds for supplying water and for carbon sequestration and other environmental services depends to a large extent on their susceptibility to soil erosion, particularly under changing climate. This study aimed to assess the risk of soil erosion in the watersheds in Bukidnon, Philippines, determine the spatial distribution of soil loss based on recent land cover maps, and predict soil loss under various rainfall scenarios based on recently reported climate change projections. The soil erosion risk assessment and soil loss prediction made use of GIS and the RUSLE model, while the rainfall scenarios were formulated based on PAGASAs prediction of drier years for Bukidnon in the early-future to late-future. Results showed that a general increase in soil loss was observed in 2015, over the period from 2010 to 2020, although some watershed clusters also showed a declining trend of soil erosion, particularly the Agusan-Cugman and Maridugao watershed clusters. Nearly 60% of Bukidnon has high to very severe soil loss rates. Under extreme rainfall change scenario with 12.61% less annual rainfall, the soil loss changes were only +1.37% and 2.87% in the category of none-to-slight and very severe, respectively. Results showed that a decrease in rainfall would have little effect on resolving the excessive soil erosion problem in Bukidnon. Results of this study suggest that having more vegetative land cover and employing soil conservation measures may prove to be effective in minimizing the risk of soil erosion in the watersheds. This study provides valuable information to enhance the sustainability of the watersheds. The erosion-prone areas identified will help decision-makers identify priority areas for soil conservation and environmental protection.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/ATMOS14030478", "year": 2023, "title": "Forecasting Air Quality in Tripoli: An Evaluation of Deep Learning Models for Hourly PM2.5 Surface Mass Concentrations", "abstract": "In this article, we aimed to study the forecasting of hourly PM2.5 surface mass concentrations in the city of Tripoli, Libya. We employed three state-of-the-art deep learning models, namely long short-term memory, gated recurrent unit, and convolutional neural networks, to forecast PM2.5 levels using univariate time series methodology. Our results revealed that the convolutional neural networks model performed the best, with a coefficient of variation of 99% and a mean absolute percentage error of 0.04. These findings provide valuable insights into the use of deep learning models for forecasting PM2.5 and can inform decision-making regarding air quality management in the city of Tripoli.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.46717/IGJ.56.1C.12MS-2023-3-23", "year": 2023, "title": "Multi-Sensor Remote Sensing Data and GIS Modeling for Mapping Groundwater Possibilities: A Case Study at the Western Side of Assiut Governorate, Egypt", "abstract": "Groundwater is an essential natural resource and it has a significant role in the development of dry lands. It is the main source of fresh water in arid and semi-arid regions. The present study investigates groundwater potentiality in the western part of Assiut Governorate, Egypt using advanced remote sensing and geospatial techniques along with hydrological data and field validation. The adopted method provides a low-cost and highly effective tool that can be combined with the conventional land-based approach for mapping Groundwater Potentiality (GWP). The study aims to determine the groundwater probability and recharging zones based on the contribution of some physiographic variables that influence groundwater storage. Therefore, multi-sensors remote sensing data from ASTER, Landsat-8, MODIS, Shuttle Radar Topography Mission (SRTM), Tropical Rainfall Measuring Mission (TRMM), and Radarsat-1 were accustomed to extract several geospatial thematic layers (variables). These layers include elevation, slope, curvature, drainage density, topographic wetness index, surface roughness, frequency of thermal anomaly, accumulated precipitation, Land Use/Land Cover (LULC), and lineament density. The produced layers are then scaled and weighted based on their contributions to the recharge of near-surface (unconfined) groundwater aquifers through infiltration and percolation processes. The Simple Additive Weight (SAW) method was utilized to aggregate all the weighted layers for creating the GWP map. This aggregated grouped map was then classified into 5 classes, from very high to very low groundwater potentiality zones. The results show that the high GWP was associated with low terrain, high surface ruggedness, high drainage and lineament densities, and relatively close to thermal anomalies in wadi deposits, and adjacent sandy areas. The remote sensing results were validated using comprehensive field observations including, pumping tests, water wells data, and vegetation patterns in the study area. The study concluded that a groundwater possibility map based on geospatial techniques and remote sensing data can provide a robust tool in groundwater exploration, and consequently, it can be adopted elsewhere in arid regions.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5772/INTECHOPEN.109906", "year": 2023, "title": "Groundwater Dynamics in Transboundary Aquifers of Southern Africa", "abstract": "Groundwater resources are indispensable not only in water scarce or water stressed countries, but globally as a dependable reservoir and an alternative resource of freshwater. This study assessed the spatio-temporal variability of groundwater resources within two of the biggest transboundary aquifers that South Africa shares with its neighbouring countries. Groundwater dynamics in the Karoo-Sedimentary Transboundary Aquifer (KSTA) as well as the Stampriet Transboundary Aquifer System (STAS) were studied over a period of 72 years from 1948-2020. The study explored the use of historical groundwater storage data acquired through the use of Remote Sensing (RS) techniques, coupled with the use of Geographical Information Systems (GIS) to map spatio-temporal variability in groundwater storage. Groundwater resources of the Karoo-Sedimentary Transboundary Aquifer were found to be declining over time, with an overall decline of just over 5.4 km3, whereas groundwater resources in the Stampriet remained relatively constant, with an overall increase of 0.2 km3 over the past 72 years. The results show that RS techniques coupled with GIS applications are invaluable where there is a dearth of scientific data and information, furthermore, their use in the monitoring, management and protection of groundwater resources can be applicable on the local, regional and international scales.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S11356-022-23553-0", "year": 2022, "title": "Investigating the long-term trends in aerosol optical depth and its association with meteorological parameters and enhanced vegetation index over Turkey", "abstract": "Aerosol optical depth (AOD) provides useful information on particulate matter pollution at both regional and global levels. In this study, the long-term datasets of aerosols, meteorological parameters, and enhanced vegetation index (EVI) were used from September 2002 to December 2021 over Turkey. This study examined the spatiotemporal distribution of aerosols and their association with meteorological parameters (temperature (Temp), relative humidity (RH), wind speed (WS)), and EVI over Turkey from 2002 to 2021. Moreover, this study also performed a comparison of AOD retrieved from Aqua with other satellites (Terra, SeaWiFS, and MISR) and ground-based (AERONET) products. The higher mean seasonal AOD (> 0.3) was observed over Southeastern Anatolia Region due to the dust transport from the Saharan Desert and Arabian Peninsula. Moreover, AOD was positively correlated with Temp and WS in the east of Turkey, while negative correlations were observed in the coastal regions. The correlation between AOD and RH was also observed negative in most parts of Turkey. Furthermore, in the coastal region, the correlation between AOD and EVI was found to be positive, whereas a negative correlation was seen over less vegetative areas. The multi-seasonal AOD averages were calculated as 0.187, 0.183, 0.138, and 0.104 for the spring, summer, autumn, and winter seasons, respectively. The most important result of this study is the regional differences in AOD over Turkey. For new studies, AOD should be observed separately for coastal areas and the eastern part of Turkey.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.RINGEO.2022.100017", "year": 2022, "title": "Southeast Asian dust flux reconstructed using accurately dated stalagmite thorium concentrations", "abstract": "Mineral dust flux is an important component of the global climate system, but chronological uncertainties complicate interpretations of the timing and magnitude of paleo-dust fluxes. This study establishes a correlation between modern satellite-derived atmospheric dust concentration data and stalagmite thorium concentrations (from published records of stalagmites growing over the last 500 years), and subsequently applies this relationship to reconstruct Asian dust flux during the late Pleistocene using published records. Thorium is an element often associated with mineral dust, and because most stalagmite records are dated using uranium-thorium disequilibrium techniques, a spatiotemporally large, yet untapped, database of thorium concentrations exists. Specifically, 194 thorium records from South-East (SE) Asian stalagmites were compiled to produce a composite SE Asian dust flux record for the past 100,000 years. The new dust flux record is consistent with the perspective that dust flux is a function of westerly wind strength across Asia and regional aridity. Dansgaard-Oeschger (D-O) event expression within the median stalagmite 232Th record is variable, with several D-O events evident within stalagmite 18O records not evident within the new dust record. This may reflect East Asian Summer Monsoon (EASM) moisture source region Sea Surface Temperature (SST) variability (affecting stalagmite 18O) but stable westerly wind regime (resulting in invariant 232Th concentrations) or the fact that these events were too brief to trigger biome shifts. This study presents encouraging first results suggesting that stalagmite thorium concentrations partially reflect dust flux over cave sites. Although here we use a compilation of records, and the spread of data within each time slice is high, future studies at well-understood cave sites where thorium input to the cave is predominantly via dry deposition may require only single stalagmites to produce adequate absolutely dated dust reconstructions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S10874-022-09444-1", "year": 2022, "title": "Remote sensing of aerosols due to biomass burning over Kanpur, Sao-Paulo, Ilorin and Canberra", "abstract": "Aerosol affect the climate in number of ways. In order to investigate these effects, we need a deep insight into aerosols optical, physical and radiative properties. So, to understand aerosols climatology, we investigate the properties of aerosols such as aerosol optical depth (AOD) (500 nm), Angstrom exponent (AE) (440870 nm), single scattering albedo (SSA), refractive index (RI) and aerosols radiative forcing (ARF). For this purpose, we select four different AErosol RObotic NETwork (AERONET) sites located in four different continents; Kanpur, (India) Asia, Sao-Paulo, (Brazil) Southern America, IIorin, (Nigeria) Africa and Canberra, Australia. High AOD and AE is found (AOD = 0.90, AE = 1.31) in November at Kanpur and in September (AOD = 0.39, AE = 1.48) at Sao-Paulo. High AOD (1.06 and 1.12) over IIorin in January and February is found because of fog and haze. SSA shows decreasing trend with increasing wavelengths having minimum value (0.88 and 0.78 at 1020 nm) during the months of DJF and SON over Sao-Paulo and Canberra respectively. The highest value of SSA (~ 0.96) is found during the months of MAM over IIorin because of presence of coarse aerosols. The low value of SSA over Kanpur during DJF months shows dominance of fine urban/ biomass burning aerosols. Based on the values of AOD, AE and SSA, Canberra is the most pristine site. The estimated ARF values indicate that Kanpur and Ilorin sites exhibit higher TOA and BOA values as compared to Sao-Paulo. ARF at ATM is observed to be 7.4 Wm2 higher during JJA months and 10.1 Wm2 during SON months than MAM months over Kanpur. We have also observed lowest ARF efficiency (FeffBOA) of 181 Wm2 AOD1550 nm during MAM months for Sao-Paulo while the highest value of 297 Wm2 AOD1550 nm is observed during DJF months for Kanpur.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1117/1.JRS.17.014505", "year": 2023, "title": "Apple yield prediction mapping using machine learning techniques through the Google Earth Engine cloud in Kashmir Valley, India", "abstract": "Our study established a machine learning (ML) model that could predict the apple yield based on various satellite multisensor data, such as climatological, SAR backscatter, terrain distribution, and soil factors, grouped as 26 subcriteria. A total of 986 apple orchards database were collected from 2018 to 2021 in Kashmir Valley, India covering an area of 277953.7 ha farmland. The novelty of our research is the integration of Google Earth Engine cloud and ML models, namely random forest, support vector machine, extreme gradient boosting, K-nearest neighbors, and Cubist along with the geographic information system/remote sensing technology to create an accurate and comprehensive apple yield prediction model in the precision agriculture realm for highlands. The multicollinearity testing indicated that the tolerance and VIF values of all the conditioning factors were <0.1 and <6.85, respectively, indicating no multicollinearity problems among the apple yield suitability factors. Among the tested ML models, the Cubist model performed best, with R2 of 0.83, root-mean-squared error of 0.56 t / ha, and mean absolute error of 0.2 t / ha. The results showed a low mean fruit yield during 2018 of 12.36 ton / ha, whereas maximum fruit yield was reflected in 2021 of 14.05 ton / ha. The heat map revealed the highest normalized differential vegetation index along with vertical-vertical/ vertical-horizontal polarization backscatter, detected during the pre-event of severe snowfall compared to on- and postevent of snowfall for the respective years. Untimely snowing and infestation due to fungi and bacterial diseases regularly reduce fruit yield in the study area. Our study successfully used of high-resolution optical-SAR data combined with ML models as a promising tool for monitoring the yield variability over the highland areas.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1088/1748-9326/AC14ED", "year": 2021, "title": "Climate-driven acceleration in forest evapotranspiration fuelling extreme rainfall events in the Himalaya", "abstract": "Warming-induced expansion in vegetation coverage and activity can accelerate the montane hydrological regimes. However, the climate impacts on ecohydrology of forested valleys of the Himalaya are uncertain. In this study, utilizing results of about three centuries of cellulose isotope chronologies ( 13C and 18O) of dominant tree species, geo-chronological proxies, bio-geophysical dataset and simulations including satellite observations, we show an activation in the ecophysiological processes including evapotranspiration (ET) since the 1950s. Observation suggests rapid greening, while isotopic records indicate enhanced assimilation and transpiration in deciduous species vis-a-vis conifers post 1950s. Given strong vegetation-precipitation feedback and superimposed on the increasing trends of conducive atmospheric factors affecting valley-scale convective processes, intensification in forest ET is manifesting in a progressive enhancement in extreme rainfall events (EREs) since the last few decades. Results suggest that representation of ecophysiological processes and dynamics of seasonal moisture loading in observational and modelling framework is critical for understanding EREs under climate change.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00024-022-03044-6", "year": 2022, "title": "Investigation of the Vegetation Coverage Dynamics and its Relation to Atmospheric Patterns in Kabul River Basin in Afghanistan", "abstract": "The variations in vegetation coverage (defined as the area with Normalised Difference Vegetation Index (NDVI) > 0.2) and atmospheric patterns occurring during various vegetation seasons in the Kabul River Basin (KRB) in Afghanistan during 20012019 were analyzed. The analysis was done based on the NDVI, land surface temperature (LST), precipitation images from the remote sensing data, and geopotential height and temperature at 500 hPa from the retrospective datasets. The results revealed that the vegetation dynamics in KRB are impacted by both precipitation and LST. In the winter season, the LST has a more substantial role in shaping the vegetation dynamics than precipitation, while it is on contrary during the summer season. Cluster analysis showed that the four atmospheric patterns (e.g., Sub-Tropical High Pressure (STHP), Western European ridge-the Eastern Mediterranean and the Black Sea trough, Caspian Sea ridge (CSR), and the Mediterranean Sea trough-Central to Eastern Iran trough) can be identified and connected with the periods with the highest and the lowest vegetation coverage (VC) anomalies in the study area. The CSR and the Mediterranean Sea trough-the Central to Eastern Iran trough are the patterns responsible for the most positive VC anomalies. At the same time, the STHP and Western Europe ridge-the Eastern Mediterranean and the Black Sea trough are responsible for the most negative VC anomalies. As the atmospheric patterns have a significant role in shaping the vegetation status, a quick alert system to prevent agricultural areas from water or temperature stresses can be developed based on observations of them.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1134/S0001433822120209", "year": 2022, "title": "Correlation of Ground-Based and Satellite Measurements of Methane Concentration in the Surface Layer of the Atmosphere in the Tiksi Region", "abstract": "In this work, the correlation of AIRS/Aqua satellite measurements of methane concentration in the surface layer of the atmosphere with ground-based measurements at the Voeikov Main Geophysical Observatory in Tiksi in 20112020 is determined. The correlation of satellite measurements with ground measurements depends on the season. In spring and summer, the correlation exceeds the autumn correlation, and it is lowest in winter. For the winter period (December, January, and February), the decrease in correlation is associated with possible inversions of air temperature (Yurganov et al., 2016; Anisimov and Kokorev, 2015). When the temperature contrast (TC) is less than 10C (the difference between air temperatures at the surface and at a level of 4 km (600 hPa)), it is preferable to use satellite data averaged at the levels of 400500 hPa. This gives an increase in the Spearman correlation coefficient (SCC) between ground and satellite measurements from 0.44 (1000 hPa) to 0.63 (400500 hPa). However, the obtained regression relationship with a determination coefficient of 0.44 makes it problematic to use it for predicting ground-based data from satellite measurements in areas similar in climatic conditions to Tiksi.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12040-020-01546-2", "year": 2021, "title": "Sensitivity to initial conditions on the simulation of extratropical cyclone Gong formed over North Atlantic", "abstract": "Sensitivity of initial and boundary conditions (ICs) are studied for an extra-tropical cyclone (ETC, Gong (2013)) over North Atlantic Ocean using WRF model.Movement (track) and synoptic feature of Gong have been evaluated with observations. WRF could simulate the characteristics throughout life cycle of Gong.The model attained intense stage was well simulated.Cyclogenesis and Q-Vector for Gong are sensitive to the ICs and model could simulate better with 48-h lead time.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JHM-D-22-0013.1", "year": 2022, "title": "Surface Shortwave Radiative Fluxes derived from the US Air Force Cloud Depiction Forecast System World-Wide Merged Cloud Analysis", "abstract": "Abstract We present a global scale evaluation of surface shortwave (SW) radiative fluxes as derived with cloud amount information from the US Air Force Cloud Depiction Forecast System (CDFS) II World-Wide Merged Cloud Analysis (WWMCA) and implemented in the framework of the NASA Land Information System (LIS). Evaluation of this product is done against ground observations, a satellite-based product from the Moderate Resolution Imaging Spectroradiometer (MODIS), and several reanalysis outputs. While the LIS/US Air Force (USAF) product tends to overestimate the SW fluxes when compared to ground observations and satellite estimates, its performance is comparable or better than the following reanalysis products: ERA5, CFSR and MERRA-2. Results are presented using all available observations over the globe and independently for several regional domains of interest. When evaluated against ground observations over the globe the bias in the LIS/USAF product at daily time scale was about 9.34 Wm2 and the rms was 29.20 Wm2 while over the USA the bias was about 10.65 Wm2 and the rms was 35.31 Wm2, respectively. The sample sizes used were not uniform over the different regions and the quality of both ground truth and the outputs of the other products may vary regionally. It is important to note that the LIS/USAF is a NearReal-Time (NRT) product of interest for potential users and as such fills a need that is not met by most products. Due to latency issues, the level of observational inputs in the NRT product is less than in the reanalysis data.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12145-022-00904-6", "year": 2023, "title": "Flood modeling through remote sensing datasets such as LPRM soil moisture and GPM-IMERG precipitation: A case study of ungauged basins across Morocco", "abstract": "North Africa is characterized by several ungauged basins, especially in Morrocco, where satellite products could be an alternative of the lack ground-based measurements. In this study, the Land Parameter Retrieval Model (LPRM) soil moisture and the Integrated Multi-Satellite Retrievals for Global Precipitation Measurement (GPM-IMERG) were used in flood modeling in Moroccan ungauged basins (Bourrous, Al Wiza, El Hallouf and Jamala). We started with comparing GPM-IMERG Early with ground measurements from five rain gauges. Next, the Soil Conservation Service Curve Number (SCS-CN) was applied with ground precipitation measurements, LPRM and GPM-IMERG Early datasets to simulated flood events in a gauged basin, the Ghdat. Finally, this SCS-CN model was transposed with these satellite data sets validated to those ungauged basins in order to reproduce flood events. The results show that the GPM-IMERG Early is best with in situ measurements (correlation coefficient = 0.50; relative bias = 27.51%; probability of detection = 0.77; false alarm rate = 0.23), on a daily scale. The observed precipitation, LPRM and GPM-IMERG Early were performed well in validation to simulate floods in the Ghdat, where NashSutcliffe criterion range from 0.43 and 0.98 using the SCS-CN model. For Bourrous, Al Wiza, El Hallouf and Jamala all flood events and hydrographs were reproduced by GPM-IMERG Early and LPRM products. Furthermore, LPRM products were validated against soil moisture measurements with a coefficient of determine R2 between 0.72 and 0.84. The results of this work provided interesting insights for flood modeling using GPM-IMERG and LPRM satellite products in ungauged basins.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119516", "year": 2023, "title": "PM2.5-bound biogenic secondary organic aerosol tracers over a regionally representative site in central India: Characteristics and sources", "abstract": "Biogenic secondary organic aerosol (BSOA) in PM2.5 over Bhopal, central India were quantified. Fine particles were collected on Teflon filters for measuring PM2.5 mass and on quartz fiber filter for organic carbon (OC), elemental carbon (EC), and BSOA tracers, including oxidation products of isoprene, monoterpene and sesquiterpene between November 2017 and May 2018. Isoprene SOA tracers were present in the highest mean concentration (86.5 ng m3 93.5 ng m3) amongst all quantified tracers, accounting for 64% 23% of the BSOA tracers. Isoprene oxidation products, including C5-alkene triols and 2-methyltetrols, and sesquiterpene oxidation products (-caryophyllinic acid), were found to be the most abundant compound class over the study location. Correlations in the temporal variation of tracers of isoprene and monoterpene, with ozone (O3) suggested that photochemical oxidation influenced their concentrations over central India. The temporal variation of -caryophyllinic acid and comparison with the previous suggested that their concentration was potentially influenced by biomass burning. Overall, the findings suggest that oxidation products of isoprene, monoterpene and sesquiterpene can be utilized to understand the characteristics and apportionment of BSOA sources over central India.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1021/ACS.EST.2C02224", "year": 2022, "title": "Evidence against Rapid Mercury Oxidation in Photochemical Smog", "abstract": "Mercury pollution is primarily emitted to the atmosphere, and atmospheric transport and chemical processes determine its fate in the environment, but scientific understanding of atmospheric mercury chemistry is clouded in uncertainty. Mercury oxidation by atomic bromine in the Arctic and the upper atmosphere is well established, but less is understood about oxidation pathways in conditions of anthropogenic photochemical smog. Many have observed rapid increases in oxidized mercury under polluted conditions, but it has not been clearly demonstrated that these increases are the result of local mercury oxidation. We measured elemental and oxidized mercury in an area that experienced abundant photochemical activity (ozone >100 ppb) during winter inversion (i.e., cold air pools) conditions that restricted entrainment of air from the oxidized mercury-rich upper atmosphere. Under these conditions, oxidized mercury concentrations decreased day-upon-day, even as ozone and other pollutants increased dramatically. A box model that incorporated rapid kinetics for reactions of elemental mercury with ozone and OH radical overestimated observed oxidized mercury, while incorporation of slower, more widely accepted reaction rates did not. Our results show that rapid gas-phase mercury oxidation by ozone and OH in photochemical smog is unlikely.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/SU15032029", "year": 2023, "title": "Aerosol Characterization of Northern China and Yangtze River Delta Based on Multi-Satellite Data: Spatiotemporal Variations and Policy Implications", "abstract": "Horizontal and vertical distributions of aerosol properties in the Taklimakan Desert (TD), North central region of China (NCR),North China Plain(NCP), and Yangtze River Delta (YRD) were investigated by statistical analysis using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) L3 data from 2007 to 2020, to identify the similarities and differences in atmospheric aerosols in different regions, and evaluate the impact of pollution control policies developed in China in 2013 on aerosol properties in the study area. The aerosol optical depth (AOD) distribution had substantial seasonal and spatial distribution characteristics. AOD had high annual averages in TD (0.38), NCP (0.49), and YRD (0.52). However, these rates showed a decline post-implementation of the long-term pollution control policies; AOD values declined by 5%, 13.8%, 15.5%, and 23.7% in TD, NCR, NCP, and YRD respectively when comparing 20142018 to 20072013, and by 7.8%, 11.5%, 16%, and 10.4% when comparing 20192020 to 20142018. The aerosol extinction coefficient showed a clear regional pattern and a tendency to decrease gradually as height increased. Dust and polluted dust were responsible for the changes in AOD and extinction coefficients between TD and NCR and NCP and YRD, respectively. In TD, with change of longitude, dust aerosol first increased and then decreased gradually, peaking in the middle. Similarly in NCP, polluted dust aerosol first increased and then decreased, with a maximum value in the middle. The elevated smoke aerosols of NCP and YRD were significantly higher than those observed in TD and NCR. The high aerosol extinction coefficient values (>0.1 km1) were mainly distributed below 4 km, and the relatively weak aerosol extinction coefficients (>0.001 km1) were mainly distributed between 58 km, indicating that the high-altitude long-range transport of TD and NCR dust aerosols affects NCP and YRD.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.HYDROA.2022.100145", "year": 2022, "title": "Interannual variability of ice cover in the Caspian Sea", "abstract": "Satellite remote sensing data (SAR and Ocean Color), MERRA-2 reanalysis and records at Astrakhan meteorological station were used to investigate interannual variability of ice cover characteristics in the North Caspian Sea for 23 winter seasons (November 1 April 15) from 1999/2000 to 2021/2022. The maximum annual ice cover area, ice freeze onset and melt dates and ice cover duration were determined from satellite remote sensing data, mostly SAR instruments on board the European Space Agencys satellites, ranging from ERS-2 to the Sentinel-1A, -1B tandem. We propose a new band combination for Sentinel-2 MSI and Landsat-8 OLI that allows better distinguishing ice cover from clouds or land than the standard RGB composites. In the absence of SAR data, this method was used to estimate the above mentioned parameters with high spatial and temporal resolution. To assess the severity of winters, the criterion on the basis of the sum of freezing degree-days (SFDD) was applied. For this purpose, we used values of daily minimum air temperature over the North Caspian (44.4647.14N, 46.7052.90E), daily mean and daily minimum ones over its coldest eastern part (with the western border at 50E), obtained from the MERRA-2 reanalysis, as well as data from the meteorological station in Astrakhan (46.35N, 48.07E). The resulting SFDD sequences show that until the winter of 2011/2012, there was a cooling trend on average (with noticeable interannual variability), whereas after that winter it changed to warming for Astrakhan and virtually disappeared for the North Caspian and its eastern part. A noticeable interannual variability is also shown by the maximum ice area and the duration of the ice period, both parameters with maximums in the winter of 2011/2012. We discuss in detail the correspondence between the SFDD and ice cover characteristics variations, as well as previously published results. In agreement with the other authors, we find that in the 21st century, compared to the 20th century, the number of very severe and severe winters has decreased, while the number of mild winters has increased.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1111/AEC.12977", "year": 2020, "title": "Structural resistance and functional resilience of the Chaco forest to wildland fires: an approach with MODIS time series", "abstract": "Forests have resistance that allows them to resist fires without changing to another state, and resilience that allows them to recover after disturbance. These properties are determined by many structural and functional determinants that interact between them. Despite the importance of structural resistance and functional resilience to wildland fires, few studies have evaluated the combined effect that structural and functional determinants have on them. Our goal was to assess the structural resistance and functional resilience to fire using remote sensing information. We specifically assessed the combined effect of pre-fire vegetation characteristics, burn severity, and post-fire precipitation on forest structural resistance and functional resilience to fire. Eighty-five forest plots of 250 m 250 m were selected in areas that burned in 2003. For each burned plot, a paired unburned control plot of 250 m 250 m was selected outside the burned areas. We measured burn severity and post-fire precipitations (20042011). We analysed MODIS time series in order to calculate the following pre- (2002) and post-fire (2011) phenological parameters: minimum level of photosynthetic activity per year; maximum level of photosynthetic activity per year; length of growing season per year; integral of annual photosynthetic activity; relative seasonality of photosynthetic activity. Also we detected plots that changed into a shrubland eight years after the fire. Fifty three per cent of burned plots changed from forest into a shrubland state. Results show that the forest structural resistance to fire depends on the balance between the level of severity and the parameters related to pre-fire aboveground net primary production. The impact of pre-fire vegetation characteristics on functional resilience ability was driven by burn severity and its interactions with pre-fire productivity and seasonality. Results suggest that changes in forest species composition and aboveground net primary production reduced forest structural resistance and functional resilience to fire.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.161041", "year": 2023, "title": "Spatiotemporal analysis of absorbing aerosols and radiative forcing over environmentally distinct stations in East Africa during 20012018", "abstract": "East Africa (EA) suffers from the inadequate characterization of atmospheric aerosols, with far-reaching consequences of its inability to quantify precisely the impacts of these particles on regional climate. The current study aimed at characterizing absorption and radiative properties of aerosols using the long-term (20012018) AErosol RObotic NETwork (AERONET) and Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data over three environmentally specific sites in EA. The annual mean absorption aerosol optical depth (AAOD440 nm), absorption Angstrom Exponent (AAE440870 nm), total effective radius (REff), and total volume concentration (m3/m2) revealed significant spatial heterogeneity over the domain. The study domain exhibited a significant contribution of fine-mode aerosols compared to the coarse-mode particles. The monthly variation in SSA440 nm over EA explains the strength in absorption aerosols that range from moderate to strong absorbing aerosols. The aerosols exhibited significant variability over the study domain, with the dominance of absorbing fine-mode aerosols over Mbita accounting for 40 to 50 %, while weakly absorbing coarse-mode particles accounted for 8.2 % over Malindi. The study conclusively determined that Mbita was dominated by AAOD mainly from biomass burning in most of the months, whereas Malindi was coated with black carbon. The direct aerosol radiative forcing (DARF) retrieved from both the AERONET and MERRA-2 models showed strong cooling at the top of the atmosphere (TOA; 6 to 27 Wm2) and the bottom of the atmosphere (BOA, 7 to 66 Wm2). However, significant warming was noticed within the atmosphere (ATM; +14 to +76 Wm2), an indication of the role of aerosols in regional climate change. The study contributed to understanding aerosol absorption and radiative characteristics over EA and can form the basis of other related studies over the domain and beyond.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11356-022-20022-6", "year": 2022, "title": "Long-term climatology and spatial trends of absorption, scattering, and total aerosol optical depths over East Africa during 20012019", "abstract": "The unprecedented increase in anthropogenic activities, coupled with the prevailing climatic conditions, has increased the aerosol load over East Africa (EA). Given this, the present study examined the trends in total, absorption, scattering, and total aerosol extinction optical depth (TAOD, AAOD, SAOD, and TAEOD) over EA, alongside trends in single scattering albedo (SSA). For this purpose, the AOD of different optical properties retrieved from multiple sensors and the Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) model between January 2001 to December 2019 were utilized to estimate trends and assess their statistical significance. The spatial patterns of seasonal mean AOD from the Moderate-resolution Imaging Spectroradiometer (MODIS) sensor and MERRA-2 model were generally characterized with high (>0.35) and low (<0.2) AOD centers over EA observed during the local dry and wet seasons, respectively. Also, the spatial trend analysis revealed a general increase in TAOD, being positive and significant over the arid and semi-arid zones of the northeastern part of EA, which is majorly dominated by locally derived dust. The local dry (wet) months generally experienced positive (negative) trends in TAOD, associated with seasonal cycles of rainfall. High and significant positive trends in AAOD were dominated over the study domain, attributed to an increased amount of biomass burning, variations in soil moisture, and changes in the rainfall pattern. The trends in TAEOD showed a distinct pattern, except over some months that depicted significant increasing trends attributed to changes in climatic conditions and anthropogenic activities. At last, the study domain exhibited decreasing trends in SSA, signifying strong absorption of direct solar radiation resulting in a warming effect. The study revealed patterns of trends in aerosol optical properties and forms the basis for further research in aerosols over EA.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1080/02626667.2022.2093642", "year": 2022, "title": "Uncertainty quantification of multi-source hydrological data products for the improvement of water budget estimations in small-scale Sakarya basin, Turkey", "abstract": "The present study aims to improve the efficacy of water budget (WB) estimations from various hydrological data products, by (1) evaluating the uncertainties of hydrological data products, (2) merging four precipitation and six evapotranspiration products using their error variances, and (3) employing the constrained Kalman filter (CKF) method to distribute residual errors among water budget components based on their relative uncertainties. The results show that applying bias correction before the merging process improved estimations of precipitation products with decreasing root mean square error (RMSE), except Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN). Variable Infiltration Capacity (VIC) and bias-corrected Climate Prediction Center Morphing Technique (CMORPH) products outperformed other evapotranspiration and bias-corrected precipitation products, respectively, in terms of mean merging weights. The terrestrial water storage change is the primary reason for non-closure errors, mainly caused by the coarse resolution of Gravity Recovery and Climate Experiment (GRACE). The CKF results were insensitive to variations in uncertainties of runoff. Precipitation derived from the CKF was the best precipitation output, with the highest correlation coefficient (CC) and smallest root mean square deviation (RMSD).", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/10106049.2022.2060325", "year": 2022, "title": "Photosynthetic trends in India derived from remote sensing measurements during 20002019: vegetation dynamics and key climate drivers", "abstract": "Significant changes in the photosynthesis of terrestrial vegetation are observed in recent decades due to climate variability, land use and land cover changes, frequent disasters and anthropogenic forcing, but this situation in the Indian context remains largely unexplored. Here, therefore, we estimate the longterm changes in photosynthesis and its key climate drivers in India. The gross photosynthetic activity peaks (FPAR mean = 0.57) in postmonsoon (September, October and November) due to high soil moisture (87.26 kg/m2), good precipitation (5.2 mm/day) and optimum temperature (21.46 C) conditions, whereas it is smallest (FPAR mean = 0.4) in summer (March, April and May) due to very high temperature (27.37 C) and lower soil moisture (55.45 kg/m2). The trend in FPAR over 20002019 reveals enhanced photosynthetic activity in India. In the northwest, both soil moisture and temperature have a positive influence on greening (i.e. moisture induced greening). Conversely, the unfavourable soil moisture and temperature conditions dominate in the peninsular region to trigger browning there (i.e. warming induced moisture stress). Our analyses suggest that the photosynthetic trend is primarily controlled by trend in the soil moisture (44.31%) and air temperature (32.54%). The warming induced moisture stress can be a serious threat in the future to drive browning in more areas. Extreme events such as droughts, landslides and fires are expected to increase in the hilly regions such as the northeast due to browning. Furthermore, as food production and forest resources influence the economy of a country like India, management and conservation of greenery are inevitable for a sustainable ecosystem.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119101", "year": 2022, "title": "Investigation on the role of aerosols on precipitation enhancement over Kerala during August 2018", "abstract": "Previous studies based on satellite data and model analysis have shown that the dust over Arabian Sea correlates positively with the Indian summer monsoon. During August 2018, over a period of a few days from August 13, the state of Kerala experienced anomalous rainfall, which was followed by heavy floods. In the present study, the meteorological factors and the aerosol conditions during this event are investigated. MERRA 2 reanalysis data suggests that the dust loading over the Arabian Sea during the month of August, during which the anomalous event of rainfall took place, is the highest in the last decade. Using CALIPSO aerosol vertical profiles, OMI Absorbing Aerosol Index and the HYSPLIT back trajectory analysis, higher altitude dust transport from the arid gulf region towards the Arabian sea and near to Kerala coast is confirmed during the heavy precipitation days and even prior to that. Changes in cloud properties like Cloud Fraction (CF), Cloud Top Temperature (CTT), Cloud Water Liquid Water Path (CWLWP) and Cloud Condensation Nuclei (CCN) with AOD variations during the period clearly indicate that there is a close relation between the aerosols and the cloud properties over the region. Observed CWLWP in the study on August 14 and 15, 2018 was 80% higher than the monthly average value. CCN concentration was increased by 23 percent during the severe rainy days of August when the CTT was about 16 K lower than the monthly mean value. Dust aerosols at altitudes of 24 km and further higher at 1015 km, along with the deep convective clouds, point to the possibility of aerosol-cloud-precipitation interaction under conducive meteorological conditions. INSAT- 3D temperature profiles show an interesting enhancement of temperature (1 K) at altitudes 3 km, where elevated dust layers are noticed. This elevated heating could pave the way for moisture convergence and it is further confirmed from the INSAT derived Relative Humidity profiles. Investigation of vertical winds shows strong updrafts over the region during the period of heavy precipitation, indicative of the coexistence of moisture and CCN at higher altitudes. The study infers that the moisture built up over the region was excessive, enough to overwhelm the commonly observed semi direct effect caused by aerosols, and in contradiction, the aerosols amplify the cloud cover and precipitation over the Kerala region during the period of study. Thus the heavy dust loading over the South Eastern Arabian Sea region, near the west coast of Kerala, together with the conducive meteorological conditions and orography of the region led to intensified precipitation over Kerala during the mid of August 2018.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/24749508.2022.2132706", "year": 2022, "title": "Spatio-temporal distribution of pollutant trace gases (CO, CH4, O3 and NO2) in India: an observational study", "abstract": "India is one of the largest contributors to anthropogenic emissions during the recent decade associated with its rapid economic growth in India. Trace gases are important components in the climate change process and due to that climate change, there will be a change in their atmospheric concentrations as the climate is sensitive to Earths; therefore, proper assessment of trace gases is necessary for ongoing sudden changes in climate. In this study, we used remote-sensing datasets from the Atmospheric Infrared Sounder (AIRS) and Ozone Monitoring Instrument (OMI) to analyze the spatio-temporal variations of four trace gases, like methane (CH4), ozone (O3), carbon monoxide (CO), and nitrogen dioxide (NO2) over India region during 20062015 and taken four seasons (i.e., winter, spring, summer, and winter) to interpret the seasonal variation. The project focuses on the temporal pattern of pollutant trace gases i.e., monthly, seasonal, and annual mean variations of trace gases, trend analysis of trace gases, and a comparison of the seasonal behavior of the trace gases by trend analysis was assessed. Higher concentrations of CO show east-to-west, CH4 show north-to-south, and O3 south-to-north gradient, indicating the variations in trace gases due to the impact of emissions and local meteorology. On the other hand, due to immense population density, huge traffic emissions, tremendous, polluted air, and overgrown industrial activities, total NO2 concentrations shoot up over Delhi, Lucknow, and Kolkata. Now as a result of seasonal variation in the long-range transport of air parcels and biomass burning activities, all trace gases shown significant seasonal variations in the spring season and substantially reduced in the summer season. However, in the winter season, O3 concentration evaluates minimum due to less amount of heat on cold days which leads to the reduction of O3 formation. Due to trace gases, all are significant to get regional climate variability. In this study by taking 2006 as a base year and investigate the behaviors of gases for 20072015 years to exhibit the increment and decrements in four seasons of all trace gases by taking the most populated 11 different cities of India.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.4236/GEP.2022.105011", "year": 2022, "title": "The Dust Comportment in the Latitudinal Band 10 North - 20 North in Africa: Emission and Deposition", "abstract": "The three measurement periods: the TOMS Nimbus-7 TOMSN7L3 v008 from 1978 to 1993, the TOMS EP TOMSEPL3 v008 from 1996 to 2005 and the OMI OMTO3d v003 from 2004 to 2008 have allowed the presence of dust to be observed in the 10 North to 20 North latitudinal band (10 - 20 band) of Africa. The 10 - 20 band has a permanent dust presence. The AERONET data show AOD peaks exceeding 2 in Senegal and Niger (on an AOD scale). The statistical study reveals intra-annual relationships in deposition. In Senegal, a significant deposition is observed.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5897/AJEST2022.3112", "year": 2022, "title": "Impact of dust accumulation and deposits on polycrystalline solar panel: Case of Senegal", "abstract": "This study focuses on the Sahel, one of the areas with the highest concentration of desert dust, with source areas having fine particle emissions in Chad, Niger, Mauritania, etc. It also includes areas of subsidence of air masses that promote the deposition of dust, such as Senegal. It turns out that the countries of Sahel are among the poorest in the world. They have a relatively low electrification rate. However, this area is also characterized by its good solar potential which makes it an ideal place for the installation of photovoltaic solar collectors. Senegal has launched the challenge to solve this problem of electrification by turning to renewable energies. But being a drop zone, the sensors on the ground will be impacted. This study defines the impact of the thickness of the dust deposit layer on a polycrystalline photovoltaic sensor. By looking at the behaviour of irradiation and aerosol deposition in Senegal with the ERA5 and Giovanni data, the intra-annual profile of deposition and irradiation in Senegal was established. By applying the results obtained on the climatology of these parameters to a monocrystalline solar photovoltaic collector, it was contrasted that the evolution of the power, as well as the yield of the collector was strongly impacted by the accumulation of the deposit after 5 years. The power delivered by the collector went from 59.779 W during the month of the 1st year of accumulation to 4.28 W during the last month of the 5th year of accumulation. The resulting yield is also affected. More detailed illustrations are given in this work.\n\n\t \n\n\tKey words: Dust, accumulation, photovoltaic, polycrystalline, efficiency, Senegal.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JHYDROL.2022.128676", "year": 2022, "title": "Impact of prevailing atmospheric conditions on diurnal variability of the pre-monsoon rainfall over a tropical location, Kolkata", "abstract": "The annual rainfall amount over Gangetic West Bengal is predominantly determined by monsoon (June to September) and pre-monsoon (March to May) rain events. Consequently, such seasonal precipitation is directly linked to the socio-economic advancement of the area. In this paper, some characteristics of pre-monsoon rainfall over a tropical urban location, Kolkata have been explored utilizing ground-based observations. Pre-monsoon rainfall over Kolkata is characterized by convective rain events and thunderstorms, mostly occurring from afternoon to night (15:30 IST 21:30 IST) span. Emphasis has been given to the set-in time of pre-monsoon rain events, based upon which they are classified as expected (14:30 IST 18:30 IST) and delayed (after 18:30 IST). Efforts have been made to assess the sustaining atmospheric conditions (in terms of temperature, water vapour, liquid water content and instability parameter) associated with such rain events prevailing over two non-overlapping time spans of pre-monsoon season. The mean diurnal variations of integrated water vapour (IWV), liquid water path (LWP), and instability parameter, namely, convective available potential energy (CAPE) during the expected and delayed rain event dates show distinct intensity in the increasing trends prior to the respective rainfall peaks. It has been observed that for the delayed events, the temperature difference between ground and 2000 m altitude begins to fall at a later part of the evening in comparison with the expected ones. Overall the investigated parameters exhibited distinguishable nature of variations for the two classes of rain events over the study location.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSMA.2022.102742", "year": 2023, "title": "Mapping marine habitats in the Gulf of Guinea: A contribution to the future establishment of Marine Protected Areas in Principe Island", "abstract": "Accurate mapping of marine benthic habitats, using acoustic technologies such as Side-Scan Sonar (SSS), is a useful tool for marine conservation and management, as well as to support zoning processes of maritime activities in the coastal environment. Georeferenced habitat maps can improve management of isolated tropical coastal and marine ecosystems, where rapid unsustainable anthropogenic coastal development often occurs. In this study, SSS was employed to map subtidal marine habitats of Principe Island (Gulf of Guinea, West Africa) to determine areas of especial interest for biodiversity or marine resource conservation. The SSS methodology was applied, during the BIO-Principe Scientific Expedition (2016), in four target areas, both inside and outside its UNESCO Biosphere Reserve, covering 675 ha between 3 and 30 m depth, also combining SCUBA diving and video transects. These areas were chosen based on their geographical location and habitat information, provided by the local stakeholders. Over the total surface mapped, five main habitats were recorded: sandy seabeds (flat sandbanks and rippled sandbanks), rhodolith seabeds (rhodoliths interspersed with scleractinian coral colonies and macroalgae), biogenic (mud/sedimentary) seabeds, and rocky seabed (bedrock and rocky reefs). In the northern, eastern, and southern areas of the island, sandy bottoms with ripples, interspersed with small biogenic sedimentary beds and rhodolith bottoms predominated. The southwestern area, Baia das Agulhas, concentrated the greatest variability and richness of habitats, including the largest rhodolith seascape. This study provided a consistent and detailed dataset to support the creation and design of future MPAs, already planned by the Principes government, adding including essential information on areas containing key habitats (e.g. rhodoliths) not detected in previous reports.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/NRM.12298", "year": 2021, "title": "Assessment of satellite products for filling rainfall data gaps in the Amazon region", "abstract": "Rainfall data series with adequate quality and length are often incomplete or nonexistent. Thus, filling in rainfall gaps becomes necessary to complete databases. This article proposes the use of satellite products (TRMMTropical Rainfall Measuring Mission, CHIRPSClimate Hazards Group InfraRed Precipitation with Stations and CMORPHCPC Morphing Technique) to fill gaps in the rainfall historical series. The simple regression method, using satellite rainfall estimates, was tested to fill the missing data from 164 rainfall gauge stations in the Amazon region. Large dispersions were observed between rainfall data, with R2 ranging from 0.383 to 0.844, the best results were found in areas with less rainfall. As well, the greatest performance of the products was verified in the dry period, with r and d higher than 0.899 and 0.950, respectively. The product with the best representation in the region was CHIRPS, which had the lowest monthly values of mean absolute error (0.979 mm) and root mean square error (3.656 mm). The results confirm that the satellite estimates satisfactorily represent the seasonal variation of rainfall in the region, despite presenting cases of overestimation and underestimation of data. The higher performance of CHIRPS can be explained by the higher spatial resolution (0.05), allowing for more accurate weather forecasts. In fact, CHIRPS has the CHPclim model, which adds other factors to the good product performance. These characteristics justify the better performance of the CHIRPS product for filling gaps in daily rainfall data in the Amazon region, favoring the best monthly rainfall estimates for each region state analyzed. Recommendations for Resource Managers Satellite products have been increasingly used for estimating rainfall data in regions with a low number of installed rainfall gauge stations. Thus, the assessment and selection of these products needs to be elaborated for the best decision making of water resource managers. Rainfall data are important to recognize the occurrence patterns for prediction of the climatic behavior of a region. Sectors such as agriculture and disaster prevention (droughts, floods, erosion of watersheds, and river silting) need knowledge of rainfall for planning, management, and mitigation. Knowledge of rainfall behavior is very important in the Amazon region. In this case, the dry season and temperatures have been increasing due to global climate change. These changes establish conditions for more intense fires, which increases the deforestation of the region.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS13214446", "year": 2021, "title": "Improving Hourly Precipitation Estimates for Flash Flood Modeling in Data-Scarce Andean-Amazon Basins: An Integrative Framework Based on Machine Learning and Multiple Remotely Sensed Data", "abstract": "Accurate estimation of spatiotemporal precipitation dynamics is crucial for flash flood forecasting; however, it is still a challenge in Andean-Amazon sub-basins due to the lack of suitable rain gauge networks. This study proposes a framework to improve hourly precipitation estimates by integrating multiple satellite-based precipitation and soil-moisture products using random forest modeling and bias correction techniques. The proposed framework is also used to force the GR4H model in three Andean-Amazon sub-basins that suffer frequent flash flood events: upper Napo River Basin (NRB), Jatunyacu River Basin (JRB), and Tena River Basin (TRB). Overall, precipitation estimates derived from the framework (BC-RFP) showed a high ability to reproduce the intensity, distribution, and occurrence of hourly events. In fact, the BC-RFP model improved the detection ability between 43% and 88%, reducing the estimation error between 72% and 93%, compared to the original satellite-based precipitation products (i.e., IMERG-E/L, GSMAP, and PERSIANN). Likewise, simulations of flash flood events by coupling the GR4H model with BC-RFP presented satisfactory performances (KGE* between 0.56 and 0.94). The BC-RFP model not only contributes to the implementation of future flood forecast systems but also provides relevant insights to several water-related research fields and hence to integrated water resources management of the Andean-Amazon region.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ASR.2021.12.042", "year": 2022, "title": "The Greater Mekong Subregion (GMS) and tropical expansion: A regional study of convection and precipitation", "abstract": "A series of data sets including brightness temperature from HIRS-UTWV, high cloud cover, precipitation and evaporation from ERA-Interim reanalysis data, and deep convective cloud from ISCCP were used to examine the latitudinal changes of the Hadley cell in the Greater Mekong Subregion (GMS) over the 19792018 period. In the study region, a pronounce poleward expansion was found during the winter season using three metrics of expansion: latitude of maximum brightness temperature associated with the anticyclonic center; latitude of zero crossing of precipitation minus evaporation, marking the extent of the tropical region; and latitude where high cloud cover reaches 50% of its maximum tropical value. However, no trends were discovered for the summer season. During the study period, there was an increase in equatorial convection as indicated by increased high cloud cover features. When precipitation minus evaporation was less than 0, there was diminishing dry zone evidence.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/S41598-022-20303-7", "year": 2022, "title": "An ozonesonde evaluation of spaceborne observations in the Andean tropics", "abstract": "Satellite observations of ozone in the tropics have feedback from in situ measurements at sea level stations, but the tropical Andes is a region that is yet to be included in systematic validations. In this work, ozonesondes launched from the equatorial Andes were used to evaluate total column ozone (TCO) measured by spaceborne sensors TROPOMI/S5P (20182021), GOME-2/MetOp-B, OMI/Aura, and OMPS/Suomi NPP (20142021). Likewise, we evaluated tropospheric column ozone (TrCO) measured by the first two. Additionally, we evaluated TCO and TrCO from reanalysis products MERRA-2 and CAMS-EAC4. Results indicate that TCO observations by OMPS/Suomi NPP produce the closest comparison to ozonesondes ( 0.2% mean difference) followed by OMI/Aura (+ 1.2% mean difference). Thus, they outperform the sensor with the highest spatial resolution of current satellite measurements, namely TROPOMI/S5P (+ 3.7% mean difference). This overprediction is similar to the one encountered for GOME-2/MetOp-B (+ 3.2% mean difference). A positive bias with respect to soundings was also identified in TrCO measured by TROPOMI/S5P (+ 32.5% mean difference). It was found that the climatology used by TROPOMI overpredicts ozone in the troposphere when compared with the mean of Andes measurements, while both data sets are essentially the same in the stratosphere. Regarding reanalysis products, MERRA-2 compares better to ozonesondes than CAMS, both for TCO and TrCO (mean differences are 1.9% vs. 3.3%, and 11.5% vs. 22.9%, respectively). Identifying spaceborne ozone measurements that currently perform the best over the region is relevant given the present conditions of rapidly changing atmospheric composition. At the same time, ozonesonde data in this work offer an opportunity to improve satellite observations in the Andean tropics, a challenging region for space measurements.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.24057/2071-9388-2022-021", "year": 2023, "title": "The Relation Between Net Primary Productivity And Human Activities For Three Biomes In Bahia State, Brazil", "abstract": "Brazilian biomes are hotspots of global biodiversity, important biomass producers and, consequently, help maintain the worlds carbon balance. Net primary production (NPP) is a variable used to determine carbon uptake by land cover. As environmental factors and human activities vary, net primary production increases or decreases. This study aimed to evaluate NPP in three Brazilian biomes Atlantic Forest, Cerrado, and Caatinga in the state of Bahia for the last 17 years, and to understand its relationship with human activities by analyzing burned areas, as well as interrelated environmental factors, such as climate variability and soil heat flux, using remote sensing. Using the MOD17 dataset, we find evidence that the Atlantic Forest biome is the one that absorbs more carbon in comparison to the Caatinga and Cerrado biomes, with a mean annual net primary production in each one of these three biomes equal to 1,227.89 g C m-2, 913.81 g C m-2, and 803.56 g C m-2, respectively. The years of El Nino influenced all biomes, and the results showed a strong relationship between climate and NPP in the studied biomes, especially in Caatinga, which is the most sensitive to climatic variations. Besides these results, we find evidence that, in all these biomes, the NPP dynamics have been affected by the increase in land use for agricultural and livestock activities, mainly because of deforestation and burning.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.154957", "year": 2022, "title": "Early-life environmental exposures and anaemia among children under age five in Sub-Saharan Africa: An insight from the Demographic & Health Surveys", "abstract": "Background\nReports show that the majority (60%) of children under age five years in Sub-Saharan Africa are anaemic. Studies in the region have mainly focused on the effect of individual, maternal and household socioeconomic status on the prevalence of anaemia. Currently, there is limited understanding of the association between early-life environmental exposures and anaemia among children in Sub-Saharan Africa.\nObjective\nThe study examines the association between early-life environmental exposures and anaemia among children under five in Sub-Saharan Africa.\nMethods\nThe study used health and demographic data from the Demographic and Health Survey (DHS) program and environmental data from NASA's Geospatial Interactive Online Visualization ANd aNalysis Infrastructure (GIOVANNI) and Atmospheric Composition Analysis Group. Three exposure periods were defined for the study, namely: in-utero, post-utero and cumulative life exposures. Multilevel mixed-effect models were used to assess the associations between environmental exposures and anaemia in each exposure period.\nResults\nThe findings show that 63% of children in the study were anaemic. It also reveals that mean PM 2.5 exposure for in-utero (34.93 gm3), post-utero (35.23 gm3) and cumulative exposure (35.08 gm3) were seven times higher than the new air quality guideline WHO recommended. A 10 gm3 increase in in-utero, post-utero and cumulative PM 2.5 exposures was associated with 4% to 5% increase in the prevalence of anaemia among children. A 10ppbv increase in in-utero, post-utero and cumulative carbon monoxide exposures was associated with 1% increase in the prevalence of anaemia among children. The spatial risk distribution maps show that socioeconomic factors modify the spatial risk distribution pattern.\nConclusion\nThe findings of the study suggest that early-life exposure to ambient air pollution is significantly associated with anaemia among children in Sub-Saharan Africa. Thus, policies aimed at addressing air quality should be incorporated into targeted interventions for anaemia among children in the region.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS12020229", "year": 2021, "title": "Investigation of Aeolian Dust Deposition Rates in Different Climate Zones of Southwestern Iran", "abstract": "Dust and atmospheric particles have been described in southwestern Iran primarily in terms of load, concentration and transport. The passive deposition, however, has been discussed inadequately. Therefore, the relationships between different climate zones in southwestern Iran and dust deposition rates were quantified between 2014 and 2017 using both space- (second modern-era retrospective analysis for research and applications, version 2 reanalysis model) and ground-based (eolian ground deposition rate) tools. In addition, the surface meteorological records, including the wind patterns favoring the occurrence of dust events, were examined. A hot desert climate (BWh), hot semi-arid climate (BSh), and temperate hot and dry summer climate (Csa) were identified as the three dominant climate regions in the study area, exhibiting the highest average dust deposition rates. In this study, correlations between the most relevant climate patterns and deposition rate weather parameters were found to describe a regions deposition rate when a dust event occurred. Based on these results, the BSh and Csa regions were found to be associated with the seasonal cycle of dust events in March, April, and May, revealing that in the long run meteorological conditions were responsible for the varying dust deposition rates. Relatively, precipitation and temperature were the two major factors influencing dust deposition rates, not wind speed. Moreover, the peak seasonal deposition rates in the spring and summer were 8.40 t km2 month1, 6.06 t km2 month1, and 3.30 t km2 month1 for the BWh, BSh, and Csa climate regions, respectively. However, each of these climate types was directly related to the specific quantity of the dust deposition rates. Overall, the highest dust deposition rates were detected over the years studied were 100.80 t km2 year1, 79.27 t km2 year1, and 39.60 t km2 year1 for BWh, BSh, and Csa, respectively.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/W13060800", "year": 2021, "title": "Integrating Satellite Rainfall Estimates with Hydrological Water Balance Model: Rainfall-Runoff Modeling in Awash River Basin, Ethiopia", "abstract": "Hydrologic models play an indispensable role in managing the scarce water resources of a region, and in developing countries, the availability and distribution of data are challenging. This research aimed to integrate and compare the satellite rainfall products, namely, Tropical Rainfall Measuring Mission (TRMM 3B43v7) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR), with a GR2M hydrological water balance model over a diversified terrain of the Awash River Basin in Ethiopia. NashSutcliffe efficiency (NSE), percent bias (PBIAS), coefficient of determination (R2), and root mean square error (RMSE) and Pearson correlation coefficient (PCC) were used to evaluate the satellite rainfall products and hydrologic model performances of the basin. The satellite rainfall estimations of both products showed a higher PCC (above 0.86) with areal observed rainfall in the Uplands, the Western highlands, and the Lower sub-basins. However, it was weakly associated in the Upper valley and the Eastern catchments of the basin ranging from 0.45 to 0.65. The findings of the assimilated satellite rainfall products with the GR2M model exhibited that 80% of the calibrated and 60% of the validated watersheds in a basin had lower magnitude of PBIAS (", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/978-3-030-96355-2_5", "year": 2022, "title": "Our Carbon Debt: A Curriculum for Interdisciplinary Education on Climate Change", "abstract": "Although academic departments often prepare students through education on the scientific foundations of climate change from the perspectives of such fields as conservation biology, environmental geoscience, or environmental geology, our college aims to provide a broader perspective on the climate change issue. To do so, we engage students in a more targeted manner, based on their disciplinary and program focus. For some students, this involves application of geotechnology and modeling applications so they are more informed on the technology necessary for monitoring greenhouse gases and their related impacts. For others, we focus more on promoting dialogue on the educational and societal implications of climate change by integrating perspectives from environmental economics, entrepreneurship, art, and social foundations of education through active learning activities. In this chapter, we present an interdisciplinary perspective on sustainability rooted in the concept of climate debt.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSRES.2022.106496", "year": 2023, "title": "PM10 aerosol enhancement in the anticyclonic anomalies caused by the East Asian spring warming of 2021", "abstract": "This study analyzed the PM10 aerosol enhancement caused by East Asian atmospheric warming during transboundary transport in March of 2021. It was found to be cooled near the north polar area and to have shifted the polar vortices northward over the East Asian region in the mid-troposphere. The Siberian high was weakened and the East Asian region was characterized by a positive air temperature anomaly and negative zonal wind speeds. The increasing rate of air temperature anomalies at 2 m was higher in the high latitude areas over 40N in Mongolia and northeastern China, causing a decrease in zonal wind speeds at 10 m over eastern China and Korea. The anomalous variations of the MODIS-induced aerosol optical depth (AOD) were found to be positive with the highest value of +0.93 in the area ranging from northeastern China to Korea, despite the recent decreasing trends. The positive anomalous region of the MODIS-induced AOD was correlated with positive air temperatures and negative zonal wind speeds, causing enhanced formations of secondary aerosols in the atmosphere. As cold northerly winds were suppressed in the East Asian region, anomalous high pressures (anticyclonic anomalies) developed frequently in eastern China and moved to Korea. The Weather Research and Forecasting model to which meteorological and climate data were applied coupled with Chemistry (WRF-Chem) simulations on increases in the PM10 enhancement ratio, indicating enhanced formation amounts, during transboundary transport for the period of March 1315, 2021. An air mass near the high terrain surface over eastern China under the backward side of an anticyclone warmed and moved toward the relatively low terrain of the Yellow Sea and Korea in keeping with the height. Air temperature inversion developed in the anomalous warmer center in the mid-troposphere, reaching the surface of the Yellow Sea and Korea. High PM10 concentrations were constrained near the shallow inversion layer. Furthermore, the PM10 enhancement ratio showed a positive level over the Yellow Sea with nearly zero anthropogenic emissions on the surface, gradually increasing at a rate of approximately 60% in Korea. The hourly contribution by the warming-induced PM10 enhancement (PM10 CbWIE) was calculated and found to be at the highest level of 70% in Seoul, Korea. Among PM10 secondary inorganic aerosols, nitrate formations were enhanced during transboundary transport in the warming-induced anticyclone with reactions rich in ammonium. While the sulfate enhancement ratio reached a positive level over the Yellow Sea, the gradual decrease during transboundary transport may be reflected by the decreased emissions of sulfur dioxide in eastern China.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00024-021-02874-0", "year": 2021, "title": "Absorption Angstrom Exponent of Dust Aerosols Over the Tarim Basin", "abstract": "The first ever (to our knowledge) long-term characteristics of aerosol absorption optical depth (AAOD) and then absorption Angstrom exponent (AAE) over the Tarim Basin during 20052018 are investigated based on the latest Ozone Monitoring Instrument (OMI) retrievals. This paper aims at evaluating the AAOD and AAE in terms of annual, seasonal, and monthly variations, and referential AAE values of dust aerosols over the Tarim Basin. Our results reveal that the AAOD increases by a factor of nearly 2 from 2015 to 2018, with yearly average values from 0.08 to 0.14 and from 0.04 to 0.07 at 388 and 500 nm, respectively, indicating that the situation of dust aerosol pollution in the Tarim Basin has become severe in recent years. The AAE based on the AAODs at wavelengths of 388 and 500 nm over the Tarim Basin exhibits large variations, with a range of 2.53.8. The seasonality of AAOD depicts maximum levels in spring, moderate levels in winter and autumn, and minimum levels in summer, whereas the AAE shows a distinctive pattern with high values in summer and low levels in winter. The monthly mean AAOD values vary by twofold, while monthly average AAE is in a range of 2.83.3, with the lowest value in February and the highest in June. The daily AAE between 388 and 500 nm for dust episodes is found to be in a range of 3.23.6, with a mean of 3.3, which hopefully provides typical AAE values of dust aerosols over the Tarim Basin.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS12091190", "year": 2021, "title": "Situation of Urban Mobility in Pakistan: Before, during, and after the COVID-19 Lockdown with Climatic Risk Perceptions", "abstract": "The coronavirus pandemic (COVID-19) has impacted the usual global movement patterns, atmospheric pollutants, and climatic parameters. The current study sought to assess the impact of the COVID-19 lockdown on urban mobility, atmospheric pollutants, and Pakistans climate. For the air pollution assessment, total column ozone (O3), sulphur dioxide (SO2), and tropospheric column nitrogen dioxide (NO2) data from the Ozone Monitoring Instrument (OMI), aerosol optical depth (AOD) data from the Multi-angle Imaging Spectroradiometer (MISR), and dust column mass density (PM2.5) data from the MERRA-2 satellite were used. Furthermore, these datasets are linked to climatic parameters (temperature, precipitation, wind speed). The KruskalWallis H test (KWt) is used to compare medians among k groups (k > 2), and the Wilcoxon signed-rank sum test (WRST) is for analyzing the differences between the medians of two datasets. To make the analysis more effective, and to justify that the variations in air quality parameters are due to the COVID-19 pandemic, a Generalized Linear Model (GLM) was used. The findings revealed that the limitations on human mobility have lowered emissions, which has improved the air quality in Pakistan. The results of the study showed that the climatic parameters (precipitation, Tmax, Tmin, and Tmean) have a positive correlation and wind speed has a negative correlation with NO2 and AOD. This study found a significant decrease in air pollutants (NO2, SO2, O3, AOD) of 3040% in Pakistan during the strict lockdown period. In this duration, the highest drop of about 28% in NO2 concentrations has been found in Karachi. Total column O3 did not show any reduction during the strict lockdown, but a minor decline was depicted as 0.38% in Lahore and 0.55% in Islamabad during the loosening lockdown. During strict lockdown, AOD was reduced up to 23% in Islamabad and 14.46% in Lahore. The results of KWt and WRST evident that all the mobility indices are significant (p < 0.05) in nature. The GLM justified that restraining human activities during the lockdown has decreased anthropogenic emissions and, as a result, improved air quality, particularly in metropolitan areas.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.46488/NEPT.2021.V20I02.030", "year": 2021, "title": "The Effect of COVID-19 on the Atmospheric Parameters Over the Indian Subcontinent", "abstract": "In the present study, the atmospheric concentrations of various pollutants over the Indian subcontinent\nbefore the COVID-19 (during 2019) and during COVID-19 phases (2020) were studied. The COVID-19\nhas created a negative impact on the countrys economy but has positivity over the atmospheric\nresources. The levels of carbon monoxide (CO), nitrogen dioxide (NO 2 ), and UV aerosol index were\nassessed using satellite images for the two different phases. The obtained results can be interpreted\nand can be substantiated with the lockdown effect due to the COVID -19 pandemic. The pollutants\nare mostly emitted from anthropogenic sources like vehicular emissions, industrial emissions, power\nplants, construction works, commercial and institutional places. It was evident that the levels of carbon\nmonoxide, nitrous dioxide and aerosols levels have drastically decreased during the lockdown period.\nHence, it can be concluded that COVID-19 has cleaned the atmospheric pollution as well as climate\nchange scenario and nature on its own.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/RS13040752", "year": 2021, "title": "Satellite Monitoring of Environmental Solar Ultraviolet A (UVA) Exposure and Irradiance: A Review of OMI and GOME-2", "abstract": "Excessive exposure to solar ultraviolet (UV) radiation has damaging effects on life on Earth. High-energy short-wavelength ultraviolet B (UVB) is biologically effective, influencing a range of dermal processes, including the potentially beneficial production of vitamin D. In addition to the damaging effects of UVB, the longer wavelength and more abundant ultraviolet A (UVA) has been shown to be linked to an increased risk of skin cancer. To evaluate this risk requires the monitoring of the solar UVA globally on a time repetitive basis in order to provide an understanding of the environmental solar UVA irradiance and resulting exposures that humans may receive during their normal daily activities. Satellite-based platforms, with the appropriate validation against ground-based instrumentation, can provide global monitoring of the solar UVA environment. Two satellite platforms that currently provide data on the terrestrial UVA environment are the ozone monitoring instrument (OMI) and the global ozone monitoring experiment (GOME-2). The objectives of this review are to provide a summary of the OMI and GOME-2 satellite-based platforms for monitoring the terrestrial UVA environment and to compare the remotely sensed UVA data from these platforms to that from ground-based instrumentation.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S12040-021-01650-X", "year": 2021, "title": "Ionospheric and atmospheric perturbations due to two major earthquakes (M >7.0)", "abstract": "The perturbation produced in the atmosphere/ionosphere associated with earthquake precursors during seismic activity of two major earthquakes which occurred on (1) 24 June 2019 in Indonesia (M = 7.3) and (2) on 19 August 2018 at Ndoi, Fiji (M = 8.2), are studied. Based on statistical analysis of total electron content (TEC) data, the presence of ionospheric perturbations 5 days before and after the main shock are found, which depends on the distance as well as direction of observation point from the epicentre. In general, ionospheric perturbations after the EQ at all the stations are found larger than that before the EQ. Probable mechanisms behind these perturbations associated with EQ are also being discussed. The ionospheric perturbations are observed at stations which are at larger distances from the epicentre, but not observed over other stations in different directions which are comparatively closer to the epicentre. These results suggest that seismic induced ionospheric anomaly is not isotropic in nature. Ozone data from three satellites: AIRS, OMI, and TOMS-like and MERRA-2 model are also analyzed 5 days before the EQ day and compared to the monthly average level. A strong link between anomalous variation in ionospheric TEC and atmospheric ozone data prior to both the EQs is noticed.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1155/2021/2835393", "year": 2021, "title": "UV Index for Public Health Awareness Based on OMI/NASA Satellite Data at King Abdulaziz University, Saudi Arabia", "abstract": "Exposure to ultraviolet radiation (UV) is essential for good health and formation of vitamin D while overexposure poses a risk to public health. Therefore, it is important to provide information to the public about the level of solar UV radiation. The ultraviolet index (UVI) is used to help avoid the negative effects of ultraviolet (UV) radiation on humans and to optimize individual exposure. There is limited ground measurement of solar UV radiation, but satellite Ozone Monitoring Instrument (OMIs) satellite products with a spatial resolution of can be used to create UV index climatology at local noon time. In this study, we utilize OMI satellite products collected over the campus of King Abdulaziz University (KAU) (21.5 North and 39.1 East), Jeddah, Saudi Arabia, to estimate changes in exposure to UV over a period of 15 years (2004-2020). The results indicate a significantly increasing trend in UV index over this period. Between 2004 and 2020, daily extreme UV (, as defined by the World Health Organization (WHO)) occurred on 46.60% of days. The frequency of low UVI () was only about 0.06%. These results imply dangerous exposure levels to solar UV radiation on the KAU campus and call for safety measures to increase awareness and decrease direct exposure; for example, by implementing the United States Environmental Protection Agency (EPA) general guidelines.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S11869-020-00946-Z", "year": 2020, "title": "Application of satellite data and GIS services for studying air pollutants in Lithuania (case study: Kaunas city)", "abstract": "Satellite remote sensing, with its relatively short history, is going to play a major role in the fields that encompass topics related to place and space. Through this innovation in technology, real-time monitoring and mapping of changing phenomena on the surface of the earth has been possible. The purpose of this study was to investigate and evaluate the Kaunas city air pollutants between 14 and 25 October 2019 using environmental station data and satellite data (Terra, Aqua, OMI, and Sentinel-5P). The data obtained from satellite and the pollutant data gathered from air quality monitoring stations located in different parts of Kaunas were used. The data was downloaded for days mentioned above for the geographical bound of Kaunas city. Each data file covered an area of the size of Lithuania; hence, we should have extracted data for the area of interest, which was Kaunas city. The overall results of this study confirmed the capability of Sentinel-5P data to be used in monitoring the air quality and air pollution over the Kaunas local area. The existence of strong and acceptable correlations between satellite data and in situ measurements was indicative of the ability of satellite images to monitor air pollution, particularly over Kaunas urban areas during the fire incident in the city of Alytus.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1134/S1024856020060196", "year": 2020, "title": "The Relationship between Ultraviolet Radiation and Meteorological Factors and Atmospheric Turbidity: Part I. Role of Total Ozone Content, Clouds, and Aerosol Optical Depth", "abstract": "We analyze the interrelation between the daily UVB radiation and a number of factors determining the absorption of UV radiation in the atmosphere (total ozone content (TOC), cloud amount, and aerosol optical depth (AOD)). This is done using a homogeneous time series of measurements of UVB radiation at the Tropospheric Ozone Research (TOR) station of the Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, from 2003 to 2016, satellite data on TOC, AOD data from the AERONET network, and data on cloud cover from the meteorological site of the Institute of Monitoring of Climatic and Ecological Systems, Siberian Branch, Russian Academy of Sciences. The regression equations are obtained, relating the increment of the diurnal intake of UV-B radiation as a function of the increment of TOC under different cloud conditions and atmospheric transparency.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1134/S000143382012035X", "year": 2020, "title": "Joint Analysis of Anomalies of Different Geophysical Fields, Recorded from Space before Strong Earthquakes in California", "abstract": "Results are presented from using satellite data to study anomalies of different geophysical fields due to the interaction of the lithosphere, atmosphere, and ionosphere. The anomalies are mid- and short-term precursors of strong earthquakes in California that occurred on July 4 and 5, 2019 (M = 6.4 and M = 7.1). Precursory changes in the lithosphere are analyzed using lineament system characteristics obtained by processing satellite imagery (Terra/Aqua satellites and MODIS instrument), along with variations in the Earths surface temperature (the Aqua satellite and the AIRS instrument). Fluctuations in the temperature of the near-surface atmospheric layer are studied to detect atmospheric anomalies during preparation of seismic events, as are fluctuations in the air temperature now at an altitude of 1000 hPa and changes in outgoing longwave radiation recorded by the AIRS instrument on the Aqua satellite. Variations in the ionospheric electron density in the F2-layer maximum are studied with GPS data to reveal ionospheric anomalies during the precursors and occurrence of earthquakes. Joint analysis of anomalies in different geophysical fields, identified via satellite monitoring, allow precursory changes in the lithosphere to be detected a month before strong earthquakes. Precursory changes in the atmosphere and ionosphere can be detected 36 days and 35 or 10 days before earthquakes, respectively.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.148518", "year": 2021, "title": "Comparison of INSAT-3D retrieved total column ozone with ground-based and AIRS observations over India", "abstract": "Ozone plays an important role in the thermal structure and chemical composition of the atmosphere. The present study compares the temporal and spatial distributions of Total Column Ozone (TCO) over the Indian sub-continent retrieved from a geostationary Indian National Satellite (INSAT-3D) and Atmospheric Infrared Sounder (AIRS). The INSAT-3D TCO values are also evaluated against the Dobson spectrophotometer observations at two locations. The inter-comparison results reveal a good correlation of 0.8, the bias of 5 DU, and Root Mean Square Error (RMSE) of 15 DU approximately between the TCO retrieved from INSAT-3D and AIRS. The lowest RMSE and highest correlation coefficient were found in the pre-monsoon season. The INSAT-3D and AIRS show reasonable agreement with the RMSE varying between 10 and 30 DU. On the other hand, evaluation of the INSAT-3D TCO with the ground-based observations from Dobson spectrophotometers located at New Delhi and Varanasi showed fair agreement with a maximum monthly mean correlation coefficient of 0.68 and 0.76, respectively, and RMSE varying from 11 to 16 DU for both the stations. The seasonal distribution of TCO and its variation over the Indian region has also been studied using INSAT-3D and AIRS data. The analysis exhibits strong seasonal variations, with higher values in pre-monsoon season and minimum values in winter season. The noticeable seasonal variability of TCO can be attributed to complex combination of photochemical and dynamical processes in the troposphere and stratosphere. The main objectives of the study are to compare the INSAT-3D TCO with two independent ground-based Dobson spectrophotometer observations and Atmospheric Infrared Sounder (AIRS) aboard NASA's Aqua satellite.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.APR.2021.02.005", "year": 2021, "title": "Temporal patterns of remote-sensed tropospheric carbon dioxide and methane over an urban site in Malawi, Southeast Africa: Implications for climate effects", "abstract": "Carbon dioxide (CO2) and Methane (CH4) are considered the most crucial climate forcing greenhouse gases due to their significant impacts on climate systems. The present study is aimed at analyzing the long-term (20042016) concentration patterns of CO2 and CH4 over Malawi located in Southeast Africa using the observations from Atmospheric Infrared Sounding (AIRS). The study found an annual increase concentration of CO2 and CH4, with a rate of 7.08% and 1.66%, respectively; whereas, the respective concentration levels of CO2 and CH4 in 2016 were noted as >400 ppm and >750 ppb, which is comparable to that reported by IPCC (2014) over the globe. The monthly and seasonal analyses revealed that high patterns are associated with biomass burning season, changes in vegetation cover, and long-range transport. The two trace gases were seasonally correlated with carbon-containing compounds produced from incomplete combustion and biomass burning. The trace gases and pollutants are emitted from the burning of crop residues during the harvesting season, besides, open burning of forests and vehicular emissions. The present study also detected a seasonal increase in CO2 and CH4 concentrations during JJA and SON seasons. The temperature (T C) exhibited profound correlation with CO2 (r = 0.75, p ", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.JASTP.2021.105652", "year": 2021, "title": "Retrieval of total columnar precipitable water vapour using radio occultation technique over the Indian region", "abstract": "Total precipitable water vapour (PWV) is retrieved using radio occultation retrievals of water vapour from COSMIC satellites over four regions of India. This analysis is carried out to assess the accuracy of the radio occultation technique for estimating PWV and to observe the PWV variation over these regions. The impact points of radio occultation are investigated for one year to select those points which are very near to the surface for the four regions. Total column PWV is estimated using these points data and further compared to the PWV values obtained from AIRS instrument and reanalysis data from MERRA2. The findings obtained using the radio occultation technique show that the vertical profile of PWV from COSMIC provides almost similar results at different pressure levels with AIRS and MERRA2 PWVs. The PWV values obtained from COSMIC are 22 mm, 17 mm, 27 mm, and 52 mm approximately for region1, region2, region3, and region4 respectively having differences in the range of 2 mm7 mm with respect to PWV values estimated from AIRS and MERRA2. On the surface level, the average difference is estimated to be less than 1 mm. It is inferred that a good estimation of total column PWV is obtained using the radio occultation technique which can be further used for rainfall prediction, its impact on climate change and to study hydrological cycle more efficiently.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3389/FEART.2022.818671", "year": 2022, "title": "A Machine-Learning Based Tool for Diagnosing Inland Tropical Cyclone Maintenance or Intensification Events", "abstract": "Tropical Cyclone Maintenance and Intensification (TCMI) is a generalized definition of tropical cyclones that strengthen or maintain intensity inland while maintaining tropical characteristics. Herein, a novel methodology, using a machine learning method was created to examine the tropical cyclone record to improve climatological representation of such cases. Using the International Best Track Archive for Climate Stewardship (IBTrACS) dataset, individual times of inland tropical cyclones were classified into TCMI and non-TCMI (weakening) events. The MERRA-2 dataset was applied to develop a prototypical machine-learning model to help diagnose future TCMI events. A list of possible TCMI storms for case studies in future analyses is provided. Two of these storms were examined for attributes characteristic of the Brown Ocean Effect, a hypothesized mechanism for TCMI centered on warm, moist soils. It was revealed that variables that were important at the time of storm arrival were important the prior day, which indicates that a TCMI event is a reaction to the environment. Moreover, the variables that were finally selected show a heavy emphasis on land-surface processes. This supports the idea that the accurate representation of the land surface state is critical to the accurate diagnosis of TCMI.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2020.1832281", "year": 2021, "title": "Investigation of seasonal variability of atmospheric columnar CO2 over India in relation to environmental parameters using OCO-2 observation and vertical redistribution model", "abstract": "This work re-explores the seasonal change of atmospheric carbon dioxide (CO2) concentration, a subject of renewable interest over half a century, in both time and frequency domain and identifies the atmospheric surface pressure and the surface air temperature as key factors for the temporal variation. The annual variability of CO2 dry-air mole fraction derived from the National Aeronautics and Space Administration Jet Propulsion Laboratory (NASA-JPL) Orbiting Carbon Observatory-2 (OCO-2) database for the region bounded by 22 N to 23 N and 86 E to 89 E was found to increase in summer, to decrease in winter and to exhibit a tendency of increase at the end of the year consistently for the years 2016 and 2017 whereas the corresponding variations of solar-induced fluorescence, surface pressure and air temperature showed partial consistency with that. The trends of these findings were cross-checked with the long-time gross variations of CO2, Normalized Difference Vegetation Index, surface pressure and surface temperature for 25 urban regions within approximately 20 N to 29 N and 69 E to 89 E obtained from NASA-Giovanni database for a period of 2010 to 2017. The periodic variations of these parameters were pin-pointed by Fourier transform. Field measurements were carried out for ground level and column-averaged CO2 concentrations in parts per million (ppm) at the region around Kolkata city (22.55 N, 88.35 E). Based on the above findings, a simple atmospheric model is developed for vertical redistribution of CO2 molecules under changed temperature and pressure causing a changed atmospheric path for radiation absorption and an apparent change in the gas concentration at any specific altitude.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JENVMAN.2021.112433", "year": 2021, "title": "xCO2 temporal variability above Brazilian agroecosystems: A remote sensing approach", "abstract": "Agriculture and soil management practices are closely related to CO2 emissions in crop fields. These practices directly interfere on the carbon dynamics between the land and atmosphere. In this study, we investigated the temporal variability of the column-averaged dry-air mole fraction of atmospheric CO2 (xCO2), solar-induced chlorophyll fluorescence (SIF), and the normalized difference vegetation index (NDVI) in areas with the main agroecosystems in southern-central Brazil as a way to understand if and how crops cycle and agricultural management could be associated with the temporal variability of NDVI, SIF and xCO2. The study was carried out in areas corresponding to the three agroecosystems: sugarcane (Pradopolis, State of Sao Paulo, Brazil), cropland with soybean-corn succession (Santo Antonio do Paraiso, State of Parana, Brazil), and grassland (Aguas Claras, State of Mato Grosso do Sul, Brazil). Air temperature, precipitation, NDVI, and SIF and xCO2 were retrieved from NASA-POWER, NASA-GIOVANNI, SATVeg-EMBRAPA, and OCO-2, respectively, during a two-year study. Trends were removed from the NDVI, SIF, and xCO2 time series applying the regression method. A negative correlation between SIF and xCO2 was found in sugarcane and cropland areas, but in grasslands, no correlation showed up. Higher SIF values were observed in grassland (2.24 W m2 sr1 m1), and lower xCO2 values were observed above grains, which varied from 396.8 to 404.2 ppm. Both xCO2 and SIF followed more a seasonal pattern in sugarcane and annual crops, but over pasture this presented an unusual pattern related to higher precipitation events. Our results indicate a potential use of SIF and xCO2 which could help identifying potential sources and sinks of the main additional greenhouse gas over agricultural areas.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.JHYDROL.2022.128765", "year": 2022, "title": "Modified Flood Potential Index (MFPI) for Flood Monitoring in Terrestrial Water Storage Depletion Basin Using GRACE Estimates", "abstract": "The Gravity Recovery and Climate Experiment (GRACE) and Follow-On (GRACE-FO) missions offer great potential for large-scale flood event monitoring. However, the effectiveness of current GRACE-based indices may be limited in areas with significant Terrestrial Water Storage (TWS) decline. In this study, a Modified Flood Potential Index (MFPI) was proposed to improve the monitoring capability for flood events in the Yarlung Tsangpo-Brahmaputra River Basin (YBRB). First, the GRACE/FO Terrestrial Water Storage Anomaly (TWSA) data gap was filled with a Multilayer Perceptron Artificial Neural Network Model (MLP-ANN). Based on the gap-filled data, the performance of the MFPI was compared with five selected indices: Flood Potential Index (FPI), Total Storage Deficit Index (TSDI), Modified Total Storage Deficit Index (MTSDI), Water Storage Deficit Index (WSDI), and Combined Climatologic Deviation Index (CCDI). Finally, the spatiotemporal monitoring ability of the MFPI was evaluated for typical and atypical flood events. We found that (1) MLP-ANN was able to predict the GRACE/FO data gap with a performance of Very Good; (2) the MFPI outperformed the FPI, TSDI, MTSDI, WSDI, and CCDI in capturing flood events, and could also reflect their spatiotemporal processes; and (3) the MFPI avoids long-term TWSA trend effects on flood event monitoring and is available for areas with significant TWSA trends. This study can provide a reference for using GRACE data to monitor large-scale flood events.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.ATMOSRES.2023.106604", "year": 2023, "title": "On the relationship between eastern China aerosols and western North Pacific tropical cyclone activity", "abstract": "How aerosols affect the weather and climate system has received increasing attention. This study finds a significant negative correlation between MarchMay eastern China aerosol optical depth (AOD) and JulyNovember western North Pacific (WNP) tropical cyclone (TC) frequency during 20032020. This time period spans when several aerosol reanalyses are available and both Terra and Aqua Moderate Resolution Imaging Spectroradiometer AOD retrievals are assimilated therein. Composite analyses and budget analyses of dynamical genesis potential indices indicate the importance of large-scale environmental factors, especially vertical velocity and vertical wind shear, associated with changes in AOD that in turn modulate changes in WNP TC frequency. Increased eastern China AOD may facilitate negative Pacific meridional mode development via modulation of the westerly jet, which then forces an anticyclonic circulation over the WNP basin. Increased AOD can also directly decrease the inter-hemispheric temperature differential and increases the intra-hemispheric temperature differential between the equator and the mid-latitudes, thus weakening ascending motion and enhancing vertical wind shear over the WNP, especially the southeastern portion of the basin. All of these large-scale environment changes induced by increased eastern China AOD tend to suppress WNP TCs. This study highlights the potential influence of eastern China aerosol loadings on WNP TCs, thus improving our understanding of TC climate variability over the WNP.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SCITOTENV.2023.161551", "year": 2023, "title": "Chemical characterization of marine aerosols from two cruises over the South China Sea: Importance of biomass burning and secondary formation", "abstract": "Total suspended particle (TSP) samples were collected during JuneJuly 2015 in the northern South China Sea (NSCS) and AugustSeptember 2016 in the western South China Sea (WSCS). Water-soluble ions (WSIs), organic carbon (OC), elemental carbon (EC), and organic compounds were measured. The average concentrations of WSIs, OC, EC and organic compounds were 19.4 10.9 g m3, 2.48 1.54 gC m3, 0.31 0.25 gC m3 and 789 217 ng m3 in the NSCS, and were 10.2 4.71 g m3, 1.76 1.82 gC m3, 0.43 0.32 gC m3 and 781 342 ng m3 in the WSCS. In both cruises, sea salt ions (Na+ and Cl) and secondary inorganic ions (SO42, NO3, and NH4+) were the main species of WSIs, accounting for 54.0 % and 43.6 % in the NSCS, and for 35.0 % and 54.0 % in the WSCS. The secondary products (dicarboxylic acids and aromatic acids) (NSCS: 73.3 %; WSCS: 73.9 %) and saccharides (NSCS: 19.0 %; WSCS: 18.0 %) accounted large fractions of organic compounds in aerosol particles over the SCS. These results suggest sea salt emissions and secondary formation are the main sources of the aerosols over the SCS in summer. The positive correlations between the biomass burning tracers (nss-K+ and levoglucosan) and OC as well as organic compounds indicated that biomass burning from nearby continents was also an important source of organic aerosols over the SCS. Based on back-trajectory analysis and satellite fire spots, Indochina Peninsula and China were proposed as the main continental source areas of non-sea salt WSIs and organic compounds. Our results highlight the significant contribution of continental outflow especially biomass burning and photochemical secondary oxidation to the organic compositions of aerosol particles over the SCS in summertime.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.SCITOTENV.2023.161509", "year": 2023, "title": "Enhanced aerosols over the southeastern Tibetan Plateau induced by open biomass burning in spring 2020", "abstract": "The Tibetan Plateau is the third pole of the world, with an essential role in regulating Northern Hemisphere climate. Previous studies showed that atmospheric aerosols over the Tibetan Plateau are influenced by biomass burning (BB) products from South and Southeast Asia. In fact, open biomass burning (OBB) is also an important form of BB in Southeast Asian countries, causing serious springtime air pollution yearly. However, there are still scientific gaps in the contribution of OBB to surrounding regional aerosols, especially on the Tibetan Plateau. In order to quantify this contribution, we collected samples of fine particulate matter and derived the concentrations of major water soluble ion, water soluble organic carbon (WSOC), and total carbon (TC) and total nitrogen (TN) as well as the dual isotopic compositions of carbon and nitrogen (13C and 15N) during MarchJune on the southeastern Tibetan Plateau. 13C and 15N showed no significant difference (p > 0.05) between the OBB and non-OBB periods. Furthermore, both 13C and 15N (25.7 0.7 and 8.0 3.6 ) values calculated during the whole sampling period were similar to the BB value, indicating that the primary source of TC and TN in aerosols was BB, whether OBB or non-OBB burning periods. TC and TN concentrations during the OBB period (6.5 2.9 g m3 and 1.2 0.4 g m3, respectively) were significantly higher than during the non-OBB period (4.1 1.7 g m3, with p = 0.014, and 0.7 0.3 g m3, with p = 0.013, respectively). Active fire data and surface smoke concentrations further indicated that BB emissions from Southeast Asia were higher during the OBB period. This suggests that OBB-related high BB emissions significantly enhanced atmospheric aerosols concentrations on the southeastern Tibetan Plateau.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1117/1.JRS.17.014507", "year": 2023, "title": "Investigating ground deformation due to a series of collapse earthquakes by means of the PS-InSAR technique and Sentinel 1 data in Kandy, Sri Lanka", "abstract": "Time series interferometry synthetic aperture radar (InSAR) techniques have rarely been applied to detect displacement due to low-magnitude (5.5 M) earthquakes. This study exploits the combined permanent scatterer (PS) interferometry (PS-InSAR) and differential interferometry (D-InSAR) methods to investigate the deformation rates due to low-magnitude partial series of collapse earthquakes. Kandy, the hill capital of Sri Lanka, was experiencing a series of collapsed earthquakes. Historical geological evidence of dynamic topography with prolonged vertical movement further promotes the initiatory InSAR investigation. A series of Sentinel 1A images from the years 2019 to 2021 were employed. Initial D-InSAR near-zero baseline analysis suggested possible displacement in the range of 10 mm / year and +2 mm / year for subsidence and uplift, respectively. Using these prior motion velocities, the temporal coherence was optimized in PS-InSAR. Variogram models and ordinary Kriging (OK) were employed to predict deformation for the areas with limited PS detection. Descending orbits images PS show a dominant uplift of +20 mm / year, which are concentrated over Kandy urban areas. Movements along the ascending line of sight at Victoria Dam in the south are in the range of 40 mm / year. Slopes along the Mahaweli river lineament to the east show subsidence in the range of 29 to 36 mm / year. The coregistered landslide hazard map of Kandy shows deformation areas are exposed to landslide risk. Changes in terrestrial and ground water levels measured with the gravity recovery and climate experiment/GRACE-Follow-On during the period reveal significant irregularities. The study can be considered a prototype example that can be extended to investigate low-magnitude incomplete collapse earthquakes in different geological and geotechnical setups for ground deformation.", "labels": [ { "id": 5, "name": "Earthquakes" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ATECH.2023.100184", "year": 2023, "title": "Assessment of irrigation water distribution using remotely sensed indicators: A case study of Doho Rice Irrigation Scheme, Uganda", "abstract": "The rising competition for scarce land and water resources and the need to satisfy the global food demand from an ever-growing population necessitates novel methods to monitor irrigation scheme performance for improved water use efficiency. The traditional methods employed in sub-Saharan Africa to assess irrigation performance are point-based, expensive, and time-consuming, making monitoring and evaluation of these capital-intensive projects difficult. This study aimed at employing satellite data with high spatial and temporal resolution in assessing the performance of Doho Rice Irrigation Scheme through estimations of actual evapotranspiration. Actual evapotranspiration (ETa) was modelled from Landsat 7 imagery using the surface energy balance system algorithm on five clear days between January and April 2020. Using equity and adequacy metrics, the derived ETa was used to assess the irrigation performance of the scheme. Results showed that the equity indicator was generally fair, with the coefficient of variation between 0.11 and 0.08, close to the 0.10 threshold implying irrigation water is fairly distributed within the scheme. The average adequacy was 0.87, above the 0.65 threshold, indicating adequate water supply throughout the scheme. The study's findings can be used in future research and benchmarking with other irrigation schemes to address the country's water resource management challenges.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.31481/UHMJ.30.2022.03", "year": 2022, "title": "The current regime of heat waves and their impact on the yield of cereal crops in Ukraine", "abstract": "Heat waves are one of the most dangerous meteorological phenomena, the manifestations of which have become more frequent in all regions of the globe in recent decades. Due to excessively high temperatures persisting for a long time, heat waves cause heat stress in living organisms and plants, and negatively affect various sectors of the national economy. Although the mechanism of heat wave formation is well known, the question of determining and predicting the intensity and duration of these processes in advance, as well as the areas of their propagation, remains open, including due to the lack of unified concept of a heat wave. This study analyzed the spatiotemporal distribution of extremely warm days and heat waves for the period 1996-2021 in 16 regions of Ukraine, where the production of the main agricultural crops (winter wheat, spring barley, corn) is concentrated. The analysis was performed using the surface skin temperature Ts, which contains information about the temperature of both the canopy and ground surface.\nIt was found that during the study period, the number of extremely warm days increased in all regions of the country and in all seasons of the year, with the most significant increase occurring in the last decade in winter and autumn. The warmest year was 2020, when the number of extremely warm days in some regions reached 100-106 per year. The frequency of heat waves at the end of the study period almost doubled compared to the beginning, reaching an average of 8-10 cases per year. The average seasonal frequency of heat waves was 4-5 cases in summer and 2-4 cases in other seasons. The longest heat waves lasting 17-19 days were recorded in all agro-climatic zones in August 2010. In other seasons, the maximum duration of heat waves did not exceed 10-14 days.\nStatistical assessment of the relationship between the seasonal number of extremely warm days and the grain yield crops showed that an increase in these days in the spring leads to decrease in the yield crops of winter wheat and spring barley; in summer this negative impact is observed for corn.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/978-981-16-4482-5_5", "year": 2022, "title": "Effect of Greenhouse Gases on Human Health", "abstract": "Greenhouse gases (GHGs) are the essential component for our planet earth to maintain an ambient condition for our survival. These gases in collaboration form an atmospheric layer which protects direct UV rays from reaching the earth. Human activities have increased the use of these gases artificially for many commercial purposes. Along with global warming and climate change greenhouse gases have adverse impacts on human health. Although human body has the capacity to cope with short-term exposure of these gases, long-term high concentration exposure becomes detrimental. The chronic exposure slowly affects multiple different organs primarily including the respiratory system, cardiovascular system, the central nervous system (CNS), the immune system, the digestive system and often the reproductive system. This chapter summarizes the mechanism of action and the adverse effects of greenhouse gases on human health and the primary target organs in an attempt to better understand the consequences of our actions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.APGEOG.2022.102869", "year": 2023, "title": "Improved air quality leads to enhanced vegetation growth during the COVID19 lockdown in India", "abstract": "The direct effect of pandemic induced lockdown (LD) on environment is widely explored, but its secondary impacts remain largely unexplored. Therefore, we assess the response of surface greenness and photosynthetic activity to the LD-induced improvement of air quality in India. Our analysis reveals a significant improvement in air quality marked by reduced levels of aerosols (AOD, 19.27%) and Particulate Matter (PM 2.5, 23%) during LD (2020)from pre-LD (MarchSeptember months for the period 20172019). The vegetation exhibits a positive response, reflected by the increase in surface greenness [Enhanced Vegetation Index (EVI, +10.4%)] and photosynthetic activity [Solar Induced Fluorescence (SiF, +11%)], during LD from pre-LD that coincides with two major agricultural seasons of India; Zaid (MarchMay) and Kharif (JuneSeptember). In addition, the croplands show a higher response [two-fold in EVI (14.45%) and four-fold in SiF (17.7%)] than that of forests. The prolonged growing period (phenology) and high rate of photosynthesis (intensification) led to the enhanced greening during LD owing to the reduced atmospheric pollution. This study, therefore, provides new insights into the response of vegetation to the improved air quality, which would give ideas to counter the challenges of food security in the context of climate pollution, and combat global warming by more greening.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/978-3-031-21644-2_15", "year": 2023, "title": "Analytical Approach of Haematology in Variation to Physical Parameters of Indian Mackerel and Yellowfin Tuna from Indian Waters", "abstract": "Study of haematology assists to understand the relationship of an organism amid the blood parameters with the habitat, as well as its susceptibility to the environment. Yellowfin tuna and Indian mackerel are two important commercial fish species in the Indian waters. Studies of haematological parameters of these two species were done from two locations, that is, the Arabian Sea and the Bay of Bengal, respectively. The purpose outlined in this study is to assess the health status of both fishes and to observe the relative similarity among the various haematological parameters. One-time sampling was done in March 2021 from Andaman and Nicobar Islands, Odisha, Kerala and Lakshadweep Islands simultaneously using requisite craft and gear. Blood samples of Indian mackerel and yellowfin tuna were taken from all these specimens and analysed for haematology. All the parameters showed a certain degree of variation, with WBC (white blood cells) in tunas dominating. Statistical analysis revealed that all the parameters were distinctly related and shared a relatively high degree of closeness. Bray-Curtis dendrogram showed maximum similarity between Andaman and Nicobar Islands and Kerala. Chlorophyll data derived through remote sensing gave a positive correlation with haematological and physio-chemical parameters. Overall, the study provides a comprehensive account of the haematology in fish which gives a positive state of the fish as well as base information for future studies from these areas. This data can be used to draw the similarities or differences between fishes from tropical water at a global scale.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.55529/JECNAM.31.41.60", "year": 2023, "title": "Hydrological Model Evaluation of Ground, GPM IMERG, and CHIRPS precipitation data for Shabelle Basin in Ethiopia", "abstract": "Consistent and accurate precipitation measurement is a fundamental input component of the hydrological model. However, most developing countries, including Ethiopia, lack consistent and precise precipitation measurements. Nevertheless, satellitebased precipitation data may play a crucial role in bridging the data gap and providing precipitation inputs for rainfall-runoff models in regions with limited ground data. The study compares the ground precipitation data from the Ethiopian meteorological agency and SWALIM to the satellite-based GPM_IMERG and CHIRPS precipitation products. HECHMS software was used to model rainfall-runoff simulation, and the study areas spatial characteristics and model development were processed with ArcGIS and HEC- GeoHMS. Since the data on hand is enough and fit for continuous event assessment, the deficit and constant loss method, a continuous event-based loss method, was tested, and found good model performance results. The onhand 14 years of precipitation and discharge data were divided into seven years for calibration and seven years for validation. Using NashSutcliffe efficiency (ENS), coefficient of determination (R2), Root Mean Square Error (RMSE), and percentage bias objective functions, the performance of the satellite precipitation was evaluated. During calibration periods (Jan 2013 to Dec 2009), the model performance showed ENS values of 0.65, R2 values of 0.68, RMSE values of 0.6, a percent bias of 0.58% for the metrological stations, ENS values of 0.61, R2 values of 0.64, RMSE values of 0.6, a percent bias of 5.38% for CHIRPS, and ENS values of 0.63, R2 values of 0.66, RMSE values of 0.7, and a percent bias of 18.9% for GMP_IMERG satellite precipitation products. During validation periods (Jan 2010 to Dec 2016), the model performance showed ENS values of 0.75, R2 values of 0.78, RMSE values of 0.6, a percent bias of -16.9% for the metrological stations, ENS values of 0.71, R2 values of 0.74, RMSE values of 0.6, a percent bias of -22.12% for CHIRPS2, and ENS values of 0.76, R2 values of 0.76, RMSE values of 0.5, and a percent bias of -0.03% for GPM_IMERG satellite precipitation products. The study showed that the HEC-HMS model performed well and gave very good results for the hydrological model for the CHIRPS and GPM_IMERG rainfall products. The study also indicates that the model outperformed well during the validation period. Overall, the study found that the simulated GPM_IMERG product gave better results than the simulated CHIRPS product.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1088/2752-5295/ACB22A", "year": 2023, "title": "Changing PM2.5 and related meteorology over India from 19502014: a new perspective from a chemistry-climate model ensemble", "abstract": "Surface PM2.5 concentrations in India have increased dramatically as emissions have risen in recent years. The role of meteorological factors in this increase is unclear, mainly due to a lack of long-term observations over the region. A 12-member ensemble of historical (19502014) simulations from the Community Earth System Model version 2-Whole Atmosphere Community Climate Model version 6 (CESM2-WACCM6) offers an unprecedented opportunity to examine simulated PM2.5 and meteorology for 20th century climates that can arise due to climate noise under the same historical greenhouse gas and air pollutant emission trajectories. CESM2-WACCM6 includes interactive aerosol and gas-phase chemistry in the atmosphere coupled to ocean-sea ice-land models, and each ensemble member differs only in its initial conditions of the climate state. We systematically examine, decade-by-decade, the changes in PM2.5 and associated meteorology, including wind speed, surface temperature inversions, boundary layer height, precipitation, and relative humidity in four cities in India: Chennai, Kolkata, Mumbai, and New Delhi. Forced changes clearly emerge in meteorological variables from 1950 to 2014, including increases in both relative humidity and temperature inversion strength, and decreases in boundary layer height and average surface wind speed. The timing of these changes varies by city: boundary layer heights decrease most over New Delhi in the premonsoon season (ensemble average decrease of 400 m), but over Mumbai in the postmonsoon season (ensemble average decrease of 100 m). PM2.5 concentrations increase across India regardless of climate variability, with an almost threefold increase from 1950 to 2014 over New Delhi. Analysis of dimensionless variables shows that PM2.5 exhibits larger ensemble mean trends and smaller variability than the trends in the meteorological variables, enabling us to infer that the increase in PM2.5 is predominantly controlled by increases in anthropogenic emissions rather than climate variability. Overall, our simulations corroborate the dominant role of air pollutant emissions on poor air quality in India.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/RS15010173", "year": 2023, "title": "Spectral Aerosol Radiative Forcing and Efficiency of the La Palma Volcanic Plume over the Izana Observatory", "abstract": "On 19 September 2021, a volcanic eruption began on the island of La Palma (Canary Islands, Spain). The eruption has allowed the assessment of an unprecedented multidisciplinary study on the effects of the volcanic plume. This work presents the estimation of the spectral direct radiative forcing (F) and efficiency (FEff) from solar radiation measurements at the Izana Observatory (IZO) located on the island of Tenerife (140 km from the volcano). During the eruption, the IZO was affected by different types of aerosols: volcanic, Saharan mineral dust, and a mixture of volcanic and dust aerosols. Three case studies were identified using ground-based (lidar) data, satellite-based (Sentinel-5P Tropospheric Monitoring Instrument, TROPOMI) data, reanalysis data (Modern-Era Retrospective Analysis for Research and Applications, version 2, MERRA-2), and backward trajectories (Flexible Trajectories, FLEXTRA), and subsequently characterised in terms of optical and micro-physical properties using ground-based sun-photometry measurements. Despite the F of the volcanic aerosols being greater than that of the dust events (associated with the larger aerosol load present), the FEff was found to be lower. The spectral FEff values at 440 nm ranged between 1.9 and 2.6 Wm2nm1AOD1 for the mineral dust and mixed volcanic and dust particles, and between 1.6 and 3.3 Wm2nm1AOD1 for the volcanic aerosols, considering solar zenith angles between 30 and 70, respectively.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.3390/APP13031355", "year": 2023, "title": "GIS-Based Urban Traffic Assessment in a Historical European City under the Influence of Infrastructure Works and COVID-19", "abstract": "Urban areas have developed organically over time, driven by the economic success of cities. However, this development has usually been accompanied by the side effects of urbanization, such as increased traffic and its associated problems: traffic congestion, increased accident rates and pollution. As urban populations grow and expand, the importance of GIS lies in its ability to collect a large amount of geospatial data, including human-generated data. This data is necessary to understand the complexity of the city, set priorities, solve complicated planning problems and perform a variety of spatial analysis, which shows not only the feasibility but also the consistency of the proposed infrastructure with the requirements of a sustainable city. In this paper, we demonstrate the benefits of integrating real-time traffic data with GIS technology and remote sensing data for analyzing the impact of infrastructure works and COVID-19 on traffic in Oradea, Romania. The case study was focused on the historical center of Oradea and was based on remote sensing data collected before, during, and after traffic restrictions. The study also shows the need for using GIS and crowdsourcing-based applications in traffic analysis and planning.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.CHEMGEO.2023.121311", "year": 2023, "title": "Variations of multiple gaseous emissions associated with the great Sumatra earthquakes in 2004 and 2005", "abstract": "Three-dimensional (3D) temporal variations and correlation analysis of CO, CH4 and O3 concentrations associated with the 26 December 2004 Sumatra-Andaman MW 9.1 Earthquake and 28 March 2005 Sumatra-Nias MW 8.6 Earthquake offshore of Sumatra, Indonesia were investigated using satellite data from AQUA AIRS in order to understand the lithospheric and atmospheric interactions during seismic activities. These great earthquakes occurred in the subduction zone northwest of the Sumatra Island. It was observed that large amounts of gases were emitted from the Earth's crust into the atmosphere before, during and after the earthquakes compared to the earthquake-free periods and background areas. Anomalies in CO, CH4 and O3 concentrations occurred along the NW-trending Sumatra fault system and peak values were found in the epicenter areas. Temporally, the anomalies occurred from 3 months before the Sumatra-Andaman Earthquake to 1 month after the Sumatra-Nias Earthquake and they lasted for 7 months. The correlation coefficients between the gas parameters increased with the period closer to the earthquake occurrence. More CO and CH4 were emitted from the epicenter area and O3 was produced in the background area during earthquake preparation period and occurrence reflected in the correlation analysis. The data indicated that the gaseous anomalies were most probably attributed to the gas emissions caused by the two great earthquakes that were accompanied by intense tectonic activities and fractures produced in the crust. After the underground gases were emitted into the atmosphere, they underwent a series of physical (diffusion, convection, etc.) and chemical reactions, which consequently lead to the gases (e.g. CO, CH4 and O3) anomalies at different altitudes in the atmosphere. The results are helpful in improving the judgment ability to understand geochemical earthquake anomalies and understanding the mechanism of lithosphere-coversphere-atmosphere-ionosphere coupling (LCAIC).", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119570", "year": 2023, "title": "How to Measure the Amount of Aerosol Optical Thickness in the Atmosphere in a Simple Way: A Calitoo Handheld Sun-Photometer Measurement", "abstract": "To have useful information about the effects of atmospheric particles on visibility degradation, extinction of solar radiation, climate changes, and tropospheric corrections in remote sensing, aerosol optical thickness (AOT) plays a crucial role. So, the measurement of AOT is an essential task for atmospheric physicists. In this regard, this article presents a systematic way in a simple form using a Calitoo handheld sun-photometer (SPM) to study atmospheric AOT. Zanjan city is selected for a period of six months as an example due to existing reference data for comparison. Hence, we use a schedule distributed in seven times, including 8:00, 9:30, 10:45, solar noon, 13:45, 15:30, and 17:00 in local time. The used wavelengths for recording are 465, 540, and 619 nm. Our data analysis shows that the mean value for AOT at those wavelengths are 0.25, 0.21, and 0.20, respectively. Also, the mean Angstrom exponent (AE) extracted from the AOTs at 465, and 619 nm is 0.80. Accordingly, AE versus AOT plot demonstrates that most of the particles in Zanjans atmosphere are classified as urban industrial (64%) and dust plus mixed (36%) particles. In addition, to have a metric, a comparison between the AOT extracted from simultaneous measurements of Calitoo handheld and Cimel automatic SPMs is employed that indicates a strong correlation (r = 0.99) between them. Furthermore, OMI, Aqua MODIS, and Terra MODIS AOT products are compared with the Calitoo SPM AOT data. The results reveal that there is a better relationship between MODIS and Calitoo data than OMI. This study leads us to conclude that it can open new insights by simple instruments to study the atmospheres that are unknown to scientists due to the limitations of geographical stations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.160980", "year": 2023, "title": "Synoptic view of an unprecedented red Noctiluca scintillans bloom in the Beibu Gulf, China", "abstract": "An unprecedented red Noctiluca scintillans (RNS) bloom in February 2021 in the Beibu Gulf, China was investigated using multi-sensor imagery. The location and spatial extent of the RNS patches were delineated based on the spectral signature. A combination of satellite remote sensing and numerical model data over the region was used to detect and monitor the development and progress of the RNS bloom and figure out the possible mechanism. Multi-sensor satellite imagery demonstrates a total coverage area of >20,000 km2 for the two-phase bloom event from Feb 13 to 26, with abrupt dissipation on Feb 17 and reappearance on Feb 20. Analysis of the initialization mechanism of the bloom suggests that nutrients conveyed from the western coast of Guangdong through Qiongzhou Strait and from convective transport in the offshore area together stimulated the outbreak of the bloom. The most distinctive finding is the negative correlation between the area of RNS patches and wind speed. The abrupt disappearance of the RNS bloom deserves further study.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1134/S1024856022060276", "year": 2022, "title": "Effect of Meteorological Conditions and Long-Range Air Mass Transport on Surface Aerosol Composition in Winter Moscow", "abstract": "We discuss the results from the complex experiment aimed at studying the composition and time variations in urban aerosol in the surface air at the center of Moscow based on daily data on PM10 and PM2.5 concentrations. In addition to these continuous observations every season (for 3540 days), the total aerosol mass concentration (by gravimetric method) and 65 chemical elements in aerosol composition were measured daily. Winters 2019/2020 and 2020/2021 are considered. The aerosol composition is juxtaposed to the meteorological parameters in the surface atmosphere in Moscow, the direction of long-range air mass transport toward the Moscow region, and the distribution of dust in air over the European Russia (using the MERRA-2 reanalysis data). The detailed analysis of the aerosol elemental composition in Moscow made it possible to identify the elements of global/local spread, as well as of natural/anthropogenic genesis. Concentrations of all aerosol constituents in Moscow during winter did not exceed the corresponding daily average MPC values for the air of residential territories. It is shown that the accumulation of PM10 and PM2.5 in urban air was favored by calm weather conditions. The maximal levels of aerosol pollution were observed in December 2020 during southeasterly winds, when long-range atmospheric transport of admixtures to Moscow occurred from sources located in the southern regions of European Russia, the Caspian Depression, and western Kazakhstan.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1002/AQC.3901", "year": 2023, "title": "Assessing the benefits of the marine protected area of Punta Coles, southern Peru (south-east Pacific) on productivity of conspicuous benthic species using pre-image population analysis", "abstract": "The coastal marine protected ecosystem at Punta Coles (as a part of the Reserva Nacional de Islas, Islotes y Puntas Guaneras) is located in a highly exploited area in southern Peru and contains several commercial, bioengineering and other benthic species. Pre-image population analysis was used to estimate the transient values of intrinsic growth rate (r) based on biomass and density time series as a proxy of productivity to assess the effectiveness of protection. The outcomes obtained showed that the gastropods Concholepas concholepas, Fissurella latimartiginata and the tunicate Purya chilensis showed a reduction of productivity during recent years, whilst the sea urchin Loxechinus albus, the barnacle Balanus laevis and the bivalve Semimytilus algosus showed an opposite pattern. Several species exhibited a chaotic dynamic, coinciding with the highest productivity values. In 2016 and 2017, several species exhibited a reduction of their abundance which could be delayed responses explained by changes in oceanographic conditions (reduction of coastal upwelling), La Nina event and illegal harvest. The above notwithstanding, the results suggest that effective protection of benthic species in the protected ecosystem of Punta Coles have been partially accomplished. Therefore, this work could be considered a baseline study, permitting the subsequent monitoring of productivity of the main species inhabiting the coastal area of Punta Coles. Pre-image population analysis could be used as a complimentary analytical tool since it enables the evaluation of transient population parameters (e.g. productivity) thus aiding population management, conservation and monitoring decisions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.32776/REVBIOMED.V33I2.923", "year": 2022, "title": "Spatiotemporal distribution of fungi of clinical importance in the environment of two states of northern Mexico", "abstract": "Introduction. Some fungi species present in the environment can have serious implications in human health, particularly in persons with a compromised immune system. It has been reported that invasive and endemic mycosis present temporal and geographic variations and are influenced by global climate changes. Objective. To determine the spatiotemporal variability of fungi of importance in public health present in the environment of a region in northern Mexico. Material and methods. Air sampling was conducted at 18 urban and rural sites located in Durango and Coahuila at three seasons.Asingle-stage impactor was used and Petri dishes with dextrose Sabouraud agar supplemented with antibiotics were used. Climate data was obtained from the NASAs Giovanni database. Results. Predominant fungi in Durango were Bipolaris, Cladosporium and Aspergillus fumigatus which had a cumulative importance index of 50% while in Coahuila were Aspergillus niger, A. fumigatus, Alternaria and Bipolaris. Sites located in Coahuila recorded a larger precipitation amount in dates closer to sampling but compared to Durangos, the cumulative amount was less. Ambient temperature also influenced the type of fungi found. Conclusion. Identifying fungi genera can be useful to health professionals for diagnosis and decision-making regarding mycotic diseases and respiratory allergies by having specific knowledge about those predominant in a specific area.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1177/11786221221139529", "year": 2022, "title": "Impact of COVID-19 Pandemic on Traffic Volume and Air Quality in Urban Areas", "abstract": "The large transmission of COVID-19 has resulted in a deep impact on the surrounding urban environments, especially on air quality and traffic flows. The objective of this study was to analyze air pollutant concentrations (PM10, SO2, NO2, CO, and O3) and traffic volumes at five congested districts (Bundaran HI, Kelapa Gading, Jagakarsa, Lubang Buaya, and Kebon Jeruk) within Jakarta city impacted by the large-scale social restriction (LSSR) policy. Air quality data during three periods; before, during, and after the LSSR at five observed districts was obtained from the Department of Environment of Jakarta using the Air Quality Monitoring (AQMS) tool. While vehicle speed data were obtained from the waze data during the study period. In this study, air pollutant data during three periods; before, during, and after the LSSR were compared with vehicle speed and meteorological data using a statistical analysis. Results revealed the mean traffic volume at all five districts has greatly reduced by 19% from before to during the LSSR period. It was consistent with the mean PM10, NO2, CO, and SO2 concentrations which also dropped about 46%, 45%, 30%, and 23% respectively. In contrast, the concentrations of air pollutants significantly increased after the LSSR period. During the LSSR period, the traffic volume was negatively associated with the O3 concentration (r?=??.86, p?", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSRES.2022.106584", "year": 2023, "title": "Effects of anthropogenic aerosols and sea salt aerosols during a summer precipitation event in the Yangtze River Delta", "abstract": "Currently, we know little about the effects of anthropogenic aerosols (AAs) and sea salt aerosols (SSAs) on heavy precipitation over the densely populated coastal areas. In this view, we developed a local aerosol activation parametrization scheme which conforms to the Yangtze River Delta (YRD) characteristics using cloud condensation nucleus (CCN) with supersaturation at 0.4 (CCN0.4) and aerosol optical depth (AOD) data at 550 nm (AOD550) to improve the model performance. Meanwhile, we simulated a heavy precipitation over the YRD during early summer using the WRF-Chem model (version 4.1) with the Morrison microphysics scheme. Increased AAs and SSAs presented opposite responses in droplets concentrations and precipitation intensity. The increased AAs increased the aerosol concentrations, leading to more but smaller droplets; and the cloud droplets mixing ratio Qc was slightly increased by 17.7% due to the weakened auto-conversion from droplets to raindrops, while the rain mixing ratio Qr was decreased by about 5.7%. On the contrary, presence of SSAs increased the effective (EFC) radius of cloud droplets because of the larger particles. Along with increased AAs, due to the influences of decreased Qr and smaller droplets, probability density function (PDF) of the hourly surface rain rates shifted to the smaller values (< 0.5 mm/h), which was caused by lowered latent heat release resulting from the enhanced rain evaporative cooling and weakened condensation rate, weakening the convective intensity and updrafts. Meanwhile, decreased updrafts resulted in fewer cloud droplets being transformed to the upper air, less accretion of droplets by ice crystal and snow, and reduced ice mixing ratio Qi and snow mixing ratio Qs. The averaged surface precipitation accumulated for 24 h decreased by about 7.2%, and the intensity of radar reflectivity was decreased by about 7.0%. In contrast, presence of SSAs enhanced the auto-conversion droplets and weakened the evaporation of raindrops, thus increasing the Qr. In this case, the 24-h accumulated averaged surface rainfall was increased by about 30.1% with the larger radar reflectivity and increased area of large reflectivity values (> 20 dbz). The latent heat release and related microphysical processes were enhanced due to the changes of conversion rate, which, together with the increased Qr and larger droplets, strengthened the precipitation, increased the incidence of heavier precipitation (> 2 mm/h), and enhanced the ice-phase microphysical processes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S12517-022-11022-4", "year": 2022, "title": "Analysis of temperature inversion in Ahwaz city", "abstract": "This research is aimed to investigate the types of inversions and their intensity using atmospheric thermodynamic indices such as SI, LI, KI, and TT indices in Ahwaz station from 2010 to 2020. In this research, atmospheric upper-air sounding data from Ahwaz Synoptic Station for 00:00 GMT (local 3:30 am) during the last 11 years (2010 to 2020) and 11 km above sea level were obtained from the University of Wyoming. The results showed that the average number of events of temperature inversion in Ahwaz is 467 cases per year, of which about 28.8% is radiation temperature inversion, 9% to frontals, and the other 62.2% is temperature inversion of subsidence type. Due to air subsidence under subtropical high pressure, the share of subsidence inversions is higher than other types of inversions. But in terms of intensity, the most severe temperature inversion in Ahwaz was radiation type. The results of the intensity coefficient showed that whenever the thickness layer is less, the air temperature is higher, the incidence height is lower, the layer pressure is higher, inversion occurs near the earths surface, and the severity of inversion is also increasing, which will have devastating consequences for human health and the environment. The relationship between inversion intensity and temperature, pressure, and height parameters showed that there was an inverse and significant relationship between inversion intensity values with thickness and height. The lower the height and thickness of the layer, the more intense the inversion becomes, but the relationship between the intensity coefficient and the temperature of the layer is direct and significant so that the higher the temperature of the layer, the more severe the inversion occurred will be and vice versa. Also, the relationship between inversion intensity and atmospheric gases showed that with the increase in the amounts of these gases, the inversion severity in the city of Ahwaz has also increased significantly.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.54386/JAM.V24I4.1834", "year": 2022, "title": "Linkage between the vegetation indices and climate factors over Haryana", "abstract": "Present study was an attempt to study the relationship of Normalized Difference Vegetation Index (NDVI) and Leaf Area Index (LAI) with climatic parameters (maximum temperature, minimum temperature, relative humidity, rainfall, wind speed and aerosol optical depth) over the Indian state of Haryana using MODIS derived vegetation indices on monthly and yearly values for the time period from 2010 to 2020. The values of correlations coefficients of NDVI and LAI with climatic variables varied with the months, the nature of their variation was similar for two indices. During summer season the correlation values were maximum while these were minimum during rainy season. The overall correlation analysis revealed that the rainfall and relative humidity were positively correlated with NDVI and LAI, while the remaining climate variables had negative impact on the NDVI and LAI.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/ATMOS13121990", "year": 2022, "title": "Investigation of Two Severe Shamal Dust Storms and the Highest Dust Frequencies in the South and Southwest of Iran", "abstract": "Dust storms create some of the most critical air quality problems in the world; the Middle East, located in the dust belt, suffers substantially from dust storms. Iran, as a country in the Middle East, is affected by dust storms from multiple internal and external sources that mostly originate from deserts in Iraq and Syria (especially the Mesopotamia region). To determine the highest dust loadings in the south and west of Iran, dust frequencies were investigated in the eight most polluted stations in the west, southwest, and southern Iran for a period of 21 years from 2000 to 2021. During the studys duration, the dust frequency was much higher from 2008 to 2012, which coincided with severe droughts reported in Iraq and Syria; from which, we investigated two severe dust storms (as well as the dust sources and weather condition effects) that took place on 1517 September 2008 and 13 June 2012; we used secondary data from ground measurement stations, and satellite and modeling products. In both cases, horizontal visibility was reduced to less than 1 km at most weather stations in Iran. The measured PM10 in the first case reached 834 g m3 at Ilam station in west Iran and the IranIraq borders while the measured PM10 in the second case reached 4947 g m3 at Bushehr station in the northern shore of the Persian Gulf. The MODIS true color images and MODIS AOD detected the dust mass over Iraq, southern Iran, and Saudi Arabia in both cases; the AOD value reached 4 in the first case and 1.8 in the second case over the Persian Gulf. During these two severe dust storms, low-level jets were observed at 930 hPa atmospheric levels in north Iraq (2008 case) and south Iraq (2012 case). The output of the NAPPS model and CALIPSO satellite images show that the dust rose to higher than 5 km in these dust storm cases, confirming the influence of Shamal wind on the dust storm occurrences.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.QUAINT.2022.10.010", "year": 2023, "title": "Coccolithophore paleoproductivity since the Last Glacial Maximum in the Atlantic Ocean: Relationship with calcification and preservation variability", "abstract": "Paleoproductivity, calcification and preservation patterns are presented from calcareous nannoplankton paleo-assemblages records covering the last 25 kyr retrieved from Integrated Ocean Drilling Program Sites U1385 (3734.285N; 107.562W) and U1313 (410.0N; 3257.4W), located respectively along the Western Iberian Margin and in the North Atlantic Ocean. The main aim of the study is to provide paleoceanographic and paleoclimatic analyses together with an investigation of changes in coccolithophore calcification processes occurring in response to climate variability from the Last Glacial Maximum up to the Holocene. Coccolithophore calcification was investigated by comparing variations in coccolith thickness and total coccolith calcite; at the same time dissolution/preservation indices were used to better understand the response of coccolithophores to changes in environmental parameters. In general, the increasing CO2 recorded during the last 25 kyr has a negative effect on calcification, resulting in a reduction of the different species size-normalized thicknesses at both sites. However, differences between the responses at the two latitudes studied are identified, in particular during the Heinrich Stadials; in contrast, during both Younger Dryas and Holocene intervals, the different size-normalized species thicknesses show consistent patterns at the two sites. During the Last Glacial Maximum the influence of subtropical waters due to Azores Current recirculation leads to a moderate productivity, initially at Site U1385 and later at Site U1313. At the same time, temperature influences the calcification at both sites. At Site U1385, the temperature is the main parameter affecting the paleoproductivity during Heinrich Stadial events; in addition, during Heinrich Stadial 1 alone, it also affects the calcification. At Site U1313 the calcification processes during Heinrich Stadial events are apparently hampered by an increasing water turbidity, caused by icebergs acting as ice rafted debris transporters, which affects light filtration in the water column. Light availability is an important calcification-influencing factor. At Site U1313 during Heinrich Stadial 1 and at the Last Glacial Maximum inception, dissolution, a consequence of increased CO2 solubility in the colder ice-age ocean, has a negative influence on calcification. Furthermore, at Site U1313, in contrast to Site U1385, the continually increasing CO2 concentration recorded during the Blling-Allerd hampers both calcification and preservation.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S11869-022-01276-Y", "year": 2022, "title": "Summertime variability of aerosols and covariates over Saudi Arabia using remote sensing", "abstract": "The summer season is the longest in Saudi Arabia and thus significantly modifies the aerosol concentration in the country. Hydrometeorological parameters when exposed to and interacting with multiple source aerosols produce a radiative climatic response. This study was made to analyze the space-time dynamics of aerosol optical depth (AOD) with prevailing meteorological and surface parameters from the summer of 2003 to 2016. Level 3 daily products from Moderate Resolution Imaging Spectroradiometer (MODIS) and Multiangle Imaging Spectroradiometer (MISR) were used. Covariates such as surface temperature, ozone, and relative humidity (RH) from AIRS, and SO2, dust column mass density (CMD), and dust surface mass concentration (SMC) were also used on a daily time scale. The spatial distribution of AOD showed high concentration (0.50.9) over southern and southeastern regions, whereas relatively low concentrations were present in the northern and northwestern regions. For trend observation of AOD, the Mann-Kendall trend test was used, which manifested an increasing trend in the southern and southwestern regions, whereas a decreasing trend in the northern and central regions of Saudi Arabia was observed. Correlation analysis was performed between AOD and meteorological parameters, in which slightly similar patterns were observed for the same variables. Wavelet analysis displays significant periodicity in the 1664 band. The wavelet coherency analysis provides the abundance of in-phase, anti-phase, leading, and lagging situations in the 1664 periodic band, along with a few interjections of the 64128 periodic band. Through this, an obvious difference was concluded in space-time patterns between MODIS and MISR datasets. These findings may prove useful for short-term and long-term studies including oscillating features of AOD and covariates.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JENVMAN.2022.116580", "year": 2023, "title": "Co-occurrence patterns and environmental factors associated with rapid onset of Microcystis aeruginosa bloom in a tropical coastal lagoon", "abstract": "The environmental factors contributing to the Microcystis aeruginosa bloom (hereafter referred to as Microcystis bloom) are still debatable as they vary with season and geographic settings. We examined the environmental factors that triggered Microcystis bloom outbreak in India's largest brackish water coastal lagoon, Chilika. The warmer water temperature (25.3132.48 C), higher dissolved inorganic nitrogen (DIN) loading (10.1513.53 mol L1), strong Plimitation (N:P ratio 138.47246.86), higher water transparency (46.6273.38 cm), and low-salinity (5.459.15) exerted a strong positive influence on blooming process. During the bloom outbreak, M. aeruginosa proliferated, replaced diatoms, and constituted 7088% of the total phytoplankton population. The abundances of M. aeruginosa increased from 0.89 104 cells L1 in September to 1.85 104 cells L1 in November and reduced drastically during bloom collapse (6.22 103 cells L1) by the late November of year 2017. The decrease in M. aeruginosa during bloom collapse was associated with a decline in DIN loading (2.97 mol L1) and N:P ratio (73.95). Sentinel-3 OLCI-based satellite monitoring corroborated the field observations showing Cyanophyta Index (CI) > 0.01 in September, indicative of intense bloom and CI ", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11802-022-5298-2", "year": 2022, "title": "Vertical Chlorophyll and Dimethylsulfide Profile Simulations in Southern Greenland Sea", "abstract": "Biogenetic sulfide dimethylsulfide (DMS) plays a major role on the global climate, especially in Arctic Ocean. Accurate simulate DMS concentration is an important task. Here we introduced both biogeochemical depth-averaged model G93 and its extension model-one dimensional DMS model. Both surface concentrations, vertical profiles of chlorophyll (CHL) and DMS are simulated using the two models within southern Greenland Sea (0E10E, 70N75N) during year 2012. As the input data for the models simulations, the spatial monthly mean of methodology forcings including sea surface temperature (SST), wind speed (WIND), cloud cover (CLD), sea ice concentration (ICE) and mixed layer depth (MLD) are calculated. Satellite 8-day time series of chlorophyll-a (CHL) are used as observation data for CHL related parameter calibrations. Simos imperial formula is used as the monthly DMS observation data. The Genetic Algorithm technique is used for the parameter calibrations. The simulation results show that the most DMS related surface concentrations exhibit the normal distributions with peak during May. CHL, DMS and DMSP (dimethylsulphoniopropionate) vertical profiles are obtained for July, August and September in year 2012. CHL had the higher variation of subsurface concentration maximum (SCM) in July with the lower surface concentration value. DMS had surface higher and subsurface lower profile for the all three months. DMSP also had subsurface high in July. The SCM CHL diurnal variation in the subsurface also can be resulted from diurnal changes in MLD and vertical mixing variations, plus photolysis and wind-driven ventilations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S10661-022-10553-3", "year": 2022, "title": "Impact of extreme weather events on cropland inundation over Indian subcontinent", "abstract": "Cyclonic storms and extreme precipitation lead to loss of lives and significant damage to land and property, crop productivity, etc. The Gulab cyclonic storm formed on the 24th of September 2021 in the Bay of Bengal (BoB), hit the eastern Indian coasts on the 26th of September and caused massive damage and water inundation. This study used Integrated Multi-satellite Retrievals for GPM (IMERG) satellite precipitation data for daily to monthly scale assessments focusing on the Gulab cyclonic event. The Otsus thresholding approach was applied to Sentinel-1 data to map water inundation. Standardized Precipitation Index (SPI) was employed to analyze the precipitation deviation compared to the 20 years mean climatology across India from June to November 2021 on a monthly scale. The water-inundated areas were overlaid on a recent publicly available high-resolution land use land cover (LULC) map to demarcate crop area damage in four eastern Indian states such as Andhra Pradesh, Chhattisgarh, Odisha, and Telangana. The maximum water inundation and crop area damages were observed in Andhra Pradesh (~2700 km2), followed by Telangana (~2040 km2) and Odisha (~1132 km2), and the least in Chhattisgarh (~93.75 km2). This study has potential implications for an emergency response to extreme weather events, such as cyclones, extreme precipitation, and flood. The spatio-temporal data layers and rapid assessment methodology can be helpful to various users such as disaster management authorities, mitigation and response teams, and crop insurance scheme development. The relevant satellite data, products, and cloud-computing facility could operationalize systematic disaster monitoring under the rising threats of extreme weather events in the coming years.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 9, "name": "Floods" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1029/2022JG007049", "year": 2022, "title": "Seasonal Variation of Long-Chain Alkyl Diols Proxies in Suspended Particulate Matter of the Changjiang River Estuary", "abstract": "Long-chain alkyl diols (LCDs) were applied as indicators of salinity, sea surface temperature (SST), upwelling, and nutrient conditions in marine settings. While increasing the body of most applications of LCDs proxies reconstructed paleo-environment information, few studies reported seasonal variation in LCDs and evaluated their applicability as environmental indicators in modern marine environments. Here, the composition and distribution of LCDs in suspended particulate matter (SPM) in three seasons in the Changjiang River Estuary (CRE) were analyzed to evaluate seasonal influence on the application of LCDs as environmental indicators. We found that the reconstructed temperature based on the long-chain diol index (LDI; LDI = C30 1,15-diol/(C28 1,13-diol + C30 1,13-diol + C30 1,15-diol)) was not consistent with satellite-measured SST, likely due to vertical mixing of LCDs in this region. The 1,14-diols previously used to indicate upwelling conditions, did not reflect the nutrient distribution of this region due to the Changjiang River (CR) nutrients discharge. Our results showed that the mean relative proportions of FC32 1,15-diol (FC32 1,15-diol = C32 1,15-diol 100%/(C28 1,13-diol + C30 1,13-diol + C30 1,15-diol + C32 1,15-diol)) gradually decreased from nearshore to offshore (71.1%, 37.4%, and 16.5%, respectively), suggesting that FC32 1,15-diol was a reliable proxy for riverine input to the CRE. We found that the diol index (DI; DI = C30 1,15-diol 100/(C30 1,15-diol + C32 1,15-diol)) values were correlated strongly with salinities in spring (R2 = 0.82) and summer (R2 = 0.94), indicating that DI can be considered as a useful indicator for salinity construction in this estuary.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S10040-022-02570-W", "year": 2022, "title": "Evaluating aquifer stress and resilience with GRACE information at different spatial scales in Cambodia", "abstract": "Groundwater exploitation for different sectors in Cambodia is expanding. Groundwater levels have already begun to decline in some parts of the country. Monitoring and assessing groundwater storage (GWS) change, aquifer stress and aquifer resilience will support the proper planning and management of the countrys groundwater resources; however, information regarding groundwater in Cambodia is currently scarce. Thus, GWS change in Cambodia over the 15 years from April 2002 to March 2017 was assessed using remote-sensing-based Gravity Recovery and Climate Experiment (GRACE) and Global Land Data Assimilation System (GLDAS) datasets, with a comprehensive validation of the GRACE-derived groundwater storage anomaly (GWSA) with respect to in-situ field-based observations. The current study also investigated the impact of surface water storage (SWS) change in Tonle Sap Lake, South-East Asias largest freshwater lake, on deriving the GWS change in Cambodia. The groundwater aquifer stresses (GAS), and aquifer resilience (AR) were also evaluated. The validation results were promising, with the correlation coefficient between satellite-based estimations and ground-based measurements ranging from 0.82 to 0.88 over four subbasins. The overall decreasing rate of GWS was found to be 0.63 mm/month, with two basins having the highest declining rate of more than 1.4 mm/month. Meanwhile, the aquifer experiencing stress during the dry season had a very low ability to quickly recover from these stresses. These findings emphasise that appropriate management is urgently needed to ensure the sustainability of the groundwater resource system in this country.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S41810-022-00168-Z", "year": 2022, "title": "Temporal and Spatial Variations of Satellite-Based Aerosol Optical Depths, Angstrom Exponent, Single Scattering Albedo, and Ultraviolet-Aerosol Index over Five Polluted and Less-Polluted Cities of Northern India: Impact of Urbanization and Climate Change", "abstract": "It is widely acknowledged that factors such as population growth, urbanization's quick speed, economic growth, and industrialization all have a role in the atmosphere's rising aerosol concentration. In the current work, we assessed and discussed the findings of a thorough analysis of the temporal and spatial variations of satellite-based aerosol optical parameters such as Aerosol Optical Depth (AOD), Angstrom Exponent (AE), Single Scattering Albedo (SSA), and Ultraviolet-Aerosol Index (UV-AI), and their concentration have been investigated in this study over five polluted and less-polluted cities of northern India during the last decade 20112020. The temporal variation of aerosol optical parameters for AOD ranging from 0.2 to 1.8 with decadal mean 0.86 0.36 for Patna region shows high value with a decadal increasing trend over the study area due to rise in aerosols combustion of fossil fuels, huge vehicles traffic, and biomass over the past ten years. The temporal variation of AE ranging from 0.3 to 1.8 with decadal mean 1.72 0.11 for Agra region shows high value as compared to other study areas, which indicates a comparatively higher level of fine-mode aerosols at Agra. The temporal variation of SSA ranging from 0.8 to 0.9 with decadal mean 0.92 0.02 for SSA shows no discernible decadal pattern at any of the locations. The temporal variation of UV-AI ranging from -1.01 to 2.36 with decadal mean 0.59 0.06 for UV-AI demonstrates a rising tendency, with a noticeable rise in Ludhiana, which suggests relative dominance of absorbing dust aerosols over Ludhiana. Further, to understand the impact of emerging activities, analyses were done in seasonality. For this aerosol climatology was derived for different seasons, i.e., Winter, Pre-Monsoon, Monsoon, and Post-Monsoon. High aerosol was observed in Winter for the study areas Patna, Delhi, and Agra which indicated the particles major dominance of burning aerosol from biomass; and the worst in Monsoon and Post-Monsoon for the Tehri Garhwal and Ludhiana study areas which indicated most of the aerosol concentration is removed by rainfall. After that, we analyzed the correlation among all the parameters to better understand the temporal and spatial distribution characteristics of aerosols over the selected region. The value of r for AOD (550 nm) for regions 2 and 1(0.80) shows a strong positive correlation and moderately positive for the regions 3 and 1 (0.64), mostly as a result of mineral dust carried from arid western regions. The value of r for AE (412/470 nm) for region 3 and (0.40) shows a moderately positive correlation, which is the resultant of the dominance of fine-mode aerosol and negative for the regions 5 and 1 ( 0.06). The value of r for SSA (500 nm) for regions 2 and 1 (0.63) shows a moderately positive correlation, which explains the rise in big aerosol particles, which scatters sun energy more efficiently, and the value of r for UV-AI for regions 1 and 2 shows a strong positive correlation (0.77) and moderately positive for the regions 3 and 1 (0.46) which indicates the absorbing aerosols present over the study region.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1111/JBI.14540", "year": 2022, "title": "Contrasting genetic diversity and structure between endemic and widespread damselfishes are related to differing adaptive strategies", "abstract": "Aim Several marine biogeographical provinces meet at the Arabian Peninsula. Where and how these junctions affect species is poorly understood. We herein aimed to identify the barriers to dispersal and how these shape fish populations, leading to differing biogeographies despite shared habitat and co-ancestry. Taxon Dascyllus marginatus (endemic) and Dascyllus abudafur (widespread). Location Coral reefs from the Red Sea (RS), Djibouti, Yemen, Oman, and Madagascar. Methods We tested potential barriers to gene flow using RADseq-derived SNPs and identified whether population genetic differences on each side of these barriers were neutral or selective to relate this to the biogeography of the species. Seven locations (ranging over 5100 km) were sampled for the endemic and six (ranging over 7400 km) for the widespread species, taking 20 individuals per location, with two exceptions. Results Dascyllus marginatus populations (comprising 5648 SNPs) had an order of magnitude higher genetic differentiation compared to D. abudafur (comprising 10,667 SNPs), as well as several outlier loci that were absent in D. abudafur despite equal sampling locations. In both species, the RS and Djibouti specimens formed one genetic cluster separated from all other locations. Although ranging from the RS to Madagascar, D. abudafur was absent in Yemen and Oman. Main Conclusions Stronger genetic structure at smaller geographical scales and outlier loci in the endemic species seem associated with faster adaptation to environmental differences and selective pressure. Genetic differentiation in the widespread species is neutral and only occurs at large geographical distances. Restrictive transitions (between the Gulf of Aqaba and the RS or the RS and the Gulf of Aden) do not hinder gene flow in either species, and the environmental shift within the RS (at 22N/20N) only affected the endemic species. The genetic break in the Gulf of Aden likely reflects historical colonization processes and not contemporary environmental regimes.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3934/ENVIRONSCI.2022043", "year": 2022, "title": "Clustering analysis of PM2.5 concentrations in the South Sumatra Province, Indonesia, using the Merra-2 Satellite Application and Hierarchical Cluster Method", "abstract": "\nThe air quality monitoring system is the most prominent tool for monitoring air pollution levels, especially in areas where forest fires often occur. The South Sumatra Province of Indonesia is one of the greatest contributors to haze events in Indonesia due to peatlands fires. It does not sufficiently possess a ground monitoring system to cover rural areas, and thus, delayed actions can result in severe air pollution within this region. Therefore, the aim of this current study is to analyze the distribution and classification of PM2.5 observed from 2019 to 2021 within the South Sumatra Province, Indonesia. The acquisition of PM2.5 data was from the Merra-2 Satellite with a spatial resolution of 0.5 \n 0.625 and an hourly interval. The hierarchical cluster analysis (HCA) was applied in this study for the clustering method. The result of the study revealed that the daily mean of PM2.5 levels varied from 5.90.01 to 21.30.03 g/m3. The study area was classified into three classes: high pollution areas (HPA), moderate pollution areas (MPA) and low pollution areas (LPA), based on the HCA method. The average level of PM2.5 observed in HPA was notably higher, at 16.80.02 g/m3, followed by MPA and LPA. Furthermore, this study indicated that the highest level of PM2.5 was found during 2019, with a severe haze event in the study area due to the intensive burning of forests, bush and peatlands. As a whole, the output of this study can be used by authorities for air quality management due to forest fire events in a certain area.\n", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1007/S12145-022-00899-0", "year": 2022, "title": "Estimation of groundwater storage change in the Helmand River Basin (Afghanistan) using GRACE satellite data", "abstract": "Understanding groundwater storage dynamic changes and quantifying the trends of groundwater fluctuations in the Helmand River Basin (HRB) aquifers, where the groundwater is the main source for drinking and irrigation applications, is significantly important in order to effectively manage groundwater resources. This case study quantifies the changes in groundwater storage over 18 years (i.e., from 2003 to 2021) in the HRB by employing the Gravity Recovery and Climate Experiment (GRACE) observations and Global Land Data Assimilation System (GLDAS) data due to sparse groundwater monitoring networks and lack of ground-based information. The data of observation wells was applied to validate the results of the GRACE and GLDAS outputs. The results indicate that changes in groundwater storage on average from 2003 to 2021 are equal to (-98.6 226.84 mm or -1.9 4.38 km3/year). On average, during 2003 to 2021 groundwater table decline was -2.6 m in the HRB. The study indicates relatively strong correlation (0.75) between the GRACE derived data and direct in-situ measurements. This study highlights the effectiveness of the GRACE-derived data for the reliable estimation of groundwater storage changes in the HRB and may contribute to sustainable groundwater resources management in the region.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.46717/IGJ.55.2D.15MS-2022-10-31", "year": 2022, "title": "Dynamical Study For Aerosols Transportation For Selected Extreme Dust Storms Over Al Jazeera Region", "abstract": "The characteristics and classifications of aerosol properties in Iraq were studied in this paper. The 11 grid of monthly aerosol optical depth and angstrom exponent data of the period 2005 to 2017 in Iraq is used from Terra of MODIS. Moreover, the 11 grid of Aerosol Index is used and it is available from NASA's Data and Information Services Center for Earth Sciences (GESDISC). The backtrjectory for 12 dust extreme events over the Al-Jaziraregion was studied by using the Single-Particle Lagrangian Integrated Trajectory model (HySplit-4). The spatial-seasonal aerosol properties over Iraq were obtained from the EOS-Aura satellite by Ozone Monitoring Instrument. The high-high clusters of aerosol optical depth and Aerosol Index values which refer to high concentration have been found in western and southern Iraq however low-low clusters have been found in the winter season over the whole of Iraq. According to Angstrom Exponent, there are three kinds of aerosol modes: fine, mixture, and coarse. This classification shows the maximum area under fine aerosols mode has occurred in the winter with 13.6% whereas the spring season did not show any area with fine aerosols mode. Moreover, the coarse mode covers the maximum area during the summer season at 97.7% and the minimum area during the winter season at 77. 2%. To demonstrate the relationship between topography and aerosol characteristics, Aerosol Properties Index is used which shows the degree of aerosol coarseness in each pixel. Using Geographically Weighted Regression and Ordinary Least Squares, the Aerosol Properties Index geographical distribution is strongly influenced by topographic conditions. Where the maximum coefficient of determination has been observed in the spring (R2=0.91) from the Geographically Weighted Regression model, while Ordinary Least Squares show a lower coefficient of determination (R2=0.33), Geographically Weighted Regression in comparison to Ordinary Least Squares show a better coefficient of determination in all seasons. The back trajectory for extreme dust events shows that some sources of air masses and their path to the study area through two pressure levels (1000 mb, 850 mb) and the geographical desert in the area of the study are the main cause of dust storms in the study area.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/EARTH3040065", "year": 2022, "title": "Mapping and Prioritizing Potential Illegal Dump Sites Using Geographic Information System Network Analysis and Multiple Remote Sensing Indices", "abstract": "Due to rapid urbanization and population growth, identification and management of illegal dump sites has been a global challenge. In this study, satellite imagery and geographic information system were used to map potential illegal dump sites (PIDS). An original analytical approach was developed to identify PIDS using a set of remote sensing indices and vector files. The Network Analysis tool was used to prioritize PIDS considering driving distance between PIDS and neighboring populated points. A total of five variables (Landfills, LST, HCHO, Highways, and EVI) were considered. A study area in Saskatchewan, Canada, was selected, and the identified PIDS account for about 37.3% of the total area. Road network intensity and accessibility appear important to the occurrence of PIDS. Overall road densities in identified PIDS ranged from 0.098 to 0.251 km/km2. All five variables have observable effects on the occurrence of PIDS; however, LST and highways are recommended for future studies due to their higher membership grade and spatial sensitivity. The combination of multiple remote sensing indices and network analysis on PIDS prioritization is advantageous. The proposed PIDS mapping and prioritization method can be easily employed elsewhere.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/JMSE10111761", "year": 2022, "title": "Seasonal Variability in Present-Day Coccolithophore Fluxes in Deep Eastern Mediterranean Sea: A Multi-Year Study (20152017) of Coccolithophore Export in SE Ionian Sea at 4300 m Depth", "abstract": "This study is the first attempt to understand the coccolith flux and its seasonal variability at the deepest part of the Mediterranean Sea. Samples were obtained from the deepest Mediterranean time-series sediment trap (4300 m) moored in the SE Ionian Sea (Nestor site) from January 2015 to November 2017. Throughout the study period, the coccolith fluxes displayed a seasonality signal with high values during the late winterearly spring convective mixing period (February to April) and low flux values during summer except for some solitary peaks in June. The maximum coccolith flux was observed in March 2015 while the minimum value was recorded in November 2017. Among the nineteen identified species of heterococcoliths, the dominant species in all the samples was Emiliania huxleyi reaching up to 79%, followed by Florisphaera profunda that comprised up to 33% of the total coccolith count. For the annual cycle of 2015, the average coccolith flux for the Nestor Site at a relatively shallower depth (2000 m) was comparable and for some time intervals was lower than the coccolith flux recorded in the present study at 4300 m, while coccolith flux peaks appeared simultaneously in both traps indicating a fast sinking rate. The higher E. huxleyi, F. profunda, Gladiolithus flabellatus, and Calciosolenia brasiliensis coccolith flux at 4300 m compared with their corresponding fluxes at 2000 m can be attributed to lateral advection, resuspension, and/or the influence of Eastern Mediterranean Deep Waters (EMDWs).", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.AGWAT.2022.108019", "year": 2023, "title": "Tracking the influence of drought events on winter wheat using long-term gross primary production and yield in the Wei River Basin, China", "abstract": "The Wei River Basin (WRB) is the main winter wheat-producing area in Northwest China and plays a pivotal role in national food security and economic development. Drought is the main agro-meteorological disaster affecting winter wheat yield in this region, and the accurate assessment of the drought impacts on crop growth and yield is an important part of maintaining food security. However, commonly used assessment methods, such as correlation analysis and crop model simulation, have some limitations. In this study, based on standardized precipitation evapotranspiration index (SPEI) at multiple time scales, gross primary production (GPP) and yield data from 1990 to 2018, sensitivity analysis, Pearson correlation, and superposed epoch analysis (SEA) were used to analyze the spatiotemporal characteristics of drought in the WRB and its influence on winter wheat growth and quantitatively assess the impact of drought at different levels on winter wheat yield. The results were as follows: 1) Overall, the WRB was in a dry state with a drying trend during 19902018, and the droughts in spring, summer, and winter were the main driving forces of annual drought that seriously threatened the growth and yield of winter wheat, especially in spring (MarchMay), which is the key growth period of winter wheat. 2) The average annual GPP of winter wheat in the WRB showed a significant upward trend of 0.465 10a1, and the central part of the WRB was the region where winter wheat GPP had higher sensitivity to drought. In general, winter wheat GPP during the growing season was most sensitive to SPEI-3, indicating that seasonal water deficits had the greatest impact on winter wheat growth. 3) The yield reduction of winter wheat caused by drought presented a spatial distribution that is heavy in the north and light in the south, and as the drought grade increased, the winter wheat yield decreased more significantly, even in irrigated areas. Therefore, relevant government departments still need to strengthen the risk management of agricultural droughts in the WRB and formulate reasonable policies to maintain food security.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S11069-022-05651-X", "year": 2022, "title": "Effect of dust particles on lightning flash rate and polarity of dust storms over India", "abstract": "Six cases of dust storms that occurred over the northwestern and northern parts of India have been studied here to understand the effect of dust on the lightning characteristics of these storms. Satellite pictures show high dust content on all six storm days, and ground station data show that visibility was reduced to less than 500 m. Lightning data observed by the lightning detection network indicate that these six cases of convective dust storms produced more than 30 percent of positive CG lightning in the total CG lighting, which is considered to be very high compared to ordinary thunderstorms. Further, analysis indicates that the current carried by positive lightning is much higher than negative lightning. In some cases, the lightning flash rate reached more than 200 flashes per min (fpm). Observation shows that all these thunderstorms were accompanied by dust, and hence, incursion of the abundance of dust particles into the cloud was likely to be very high. Many earlier observations have suggested that aerosols can affect thunderstorms microphysical (such as vertical distribution of the hydrometers) and electrical characteristics. With the abundance of dust particles in the cloud and increased positive CG discharges, it has been proposed that increased dust particles can modify the vertical distribution of ice particles inside a thundercloud and affect the lightning flash rate as well as polarity.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.POCEAN.2022.102922", "year": 2022, "title": "Trophic architecture as a predictor of ecosystem resilience and resistance in the eastern Pacific", "abstract": "The intricate trophic structure of marine ecosystems defines their ecological properties and network metrics; it has been used extensively to assess the development and maturity of ecosystems. The Eastern Pacific is warming due to climate change, and added human stressors are affecting the trophic architecture of its marine ecosystems. We aimed to explore the maturity of ecosystems in this region under the assumption that the trophic architecture of an ecosystem is a proxy of maturity, and that there is a direct relationship between resistance and maturity and an inverse one with resilience. We applied ecosystem network analysis to model runs of published rebuilt Ecopath models to explore the potential effects of oceanographic variables and human disturbance on the trophic architecture of 13 ecosystem models, 11 models within three different Large Marine Ecosystems (LMEs) and two models describing oceanic islands, that have an array of oceanographic conditions and are subject to different human stressors. We conclude that even when ecosystem attributes cannot conclusively assert maturity stage, they can suggest how close or far the ecosystems are from maturity. We found that the ecosystems in the Gulf of California are resilient because they have a high median trophic level, high Production/Biomass ratio, and median ascendency/capacity ratio, and because they are subject to natural variations of productivity. Upwelling ecosystems are in an intermediate stage of maturity, followed by ecosystems from the Pacific Central American Coastal LME. As expected, oceanic islands, which have a production deficit, must optimize their energy transfer. Our analysis suggests that although trophic architecture cannot serve as a direct indicator of maturity, it can help estimate ecosystem resilience and identify those systems that can withstand future impacts.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1590/2675-2824071.22016HDSB", "year": 2022, "title": "Distribution of nutrients and chlorophyll across an equatorial reef region: Insights on coastal gradients", "abstract": "Abstract We evaluate how the concentrations of inorganic nutrients and chlorophyll a vary in a heterogeneous area (Equatorial SW Atlantic), covering a gradient from stations closer to the coast to others more distant associated or not with turbid-zone reefs. Vertical temperature (27.9 0.10 C; mean standard deviation) and salinity (36.2 0.14) profles showed that the water column is well mixed (0-30 m depth). The oligotrophic condition was marked by low concentrations of phosphate (0.30 0.22 M) and dissolved inorganic nitrogen (0.64 0.74 M). Moreover, dissolved reactive silicon (DSi) was low in most samples (< 2.0 M), but higher (>10 M) in nearshore stations, probably related to continental runoff and/or resuspension of the bottom sediments. The pelagic phytoplankton biomass indicated that chlorophyll a (0.25 0.08 g L-1) was low, positively correlated with light and negatively correlated with nutrients, indicating possible phytoplankton uptake. Chlorophyll a concentrations were lower in stations closer to the coast and higher in some stations near the reefs, indicating that the latter could be more prone to phytoplankton development and depletion of nutrients, especially DSi. Therefore, although oligotrophy is present along this coast, we found some unexpected heterogeneity of nutrient and chlorophyll a distributions, which were probably infuenced by benthic-pelagic coupling due to the presence of extensive reefs, sponge gardens (18-30 m depth), and the proximity to the coast. These results highlight the importance of understanding the heterogeneity of ocean productivity, especially in lesser known low-latitude areas, which showed distinct nutrient and chlorophyll a levels related to the occurrence of tropical reefs that are capable of supporting important fsh stocks and unique biological communities.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.159969", "year": 2023, "title": "Radiative effects of absorbing aerosol types over South Asia", "abstract": "A comprehensive study on classifying the aerosol types and absorbing aerosol types, and quantifying the effect of absorbing aerosols on aerosol optical and radiative properties using four years (20152016, 20182019) of high-quality Aerosol Robotic Network (AERONET) datasets over Kanpur (urban) and Gandhi College (rural) in the Indo-Gangetic Plain (IGP) region is conducted on a seasonal scale, for the first time. Biomass burning (BB), urban-industrial, and mixed aerosol types are always present, whereas dust aerosol and mostly dust absorbing aerosol types are only present in pre-monsoon and monsoon seasons. During winter and post-monsoon seasons, BB aerosols and mostly black carbon (MBC) absorbing aerosols dominate, and the contribution of aerosol optical depth (AOD) and single scattering albedo (SSA) corresponding to MBC to total AOD and SSA are higher. SSA for MBC varies over a broader range due to mixing of BC with water-soluble aerosols. During pre-monsoon and monsoon seasons, mixing of dust with anthropogenic aerosols increases the amount of mixed aerosol type. Surface cooling and atmospheric heating efficiency for mixed aerosols are higher than MBC and dust aerosols due to enhancement in aerosol absorption over both locations. Seasonal analysis of aerosol radiative properties showed that during winter and post-monsoon, MBC absorbing aerosols are the major contributor in controlling/influencing the total aerosol radiative forcing (ARF) and heating rate (HR). During the other seasons, each absorbing aerosol type significantly influences ARF depending on their AOD and SSA values. In addition to Kanpur and Gandhi College, data from seven other AERONET sites located at Karachi, Lahore, Jaipur, Lumbini, Pokhara, Bhola, and Dhaka in South Asia are analysed to conduct a regional-scale examination of aerosol optical parameters and radiative effects due to different absorbing aerosol types. As the aerosol characteristics and trends are similar over these sites, the findings from such a regional-scale analysis can be an appropriate representative for the South Asian region. The regional analysis revealed that the annual mean atmospheric ARF (ARFATM) and ARF efficiency (ARFEATM), and HR are higher for MBC, followed by mixed and MD aerosols over South Asia due to higher AOD, and higher absorbing efficiency of MBC aerosols. In comparison, mixed aerosols exhibit higher ARFATM over East Asia. This quantification of absorbing aerosol types over a global aerosol hotspot will be useful for an accurate quantification of climate impacts of aerosols.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2022JG007022", "year": 2022, "title": "Functional Genes Profile of Atmospheric Dust in the East Mediterranean Suggests Widespread Anthropogenic Influence on Aerobiome Composition", "abstract": "The microbiome of atmospheric dust events has raised increasing interest in the last decade, resulting in numerous studies that characterized the different parameters affecting the composition of the atmospheric microbiome, that is, the aerobiome. However, less is known about the functional profile of the aerobiome and how it compares with other environments. Here, we describe the results of shotgun metagenome analysis conducted on a representative set of particulate matter (PM) samples taken in Israel under dusty and nondusty conditions. We compared the functional profiles of these samples to local metagenomes collected from soils, sea, and leaf surfaces and to PM collected in Saudi Arabia, in order to link between the sampled aerosols and potential sources that contribute to the aerobiome. We found that PM samples collected in Israel most resembled Saudi Arabian dust and Israeli soils in both community composition and functional genes profile. In addition, we found significant differences in the abundances of genes associated with anthropogenic activity. Specifically, the examined dust exhibited a significantly higher abundance of genes associated with the biodegradation of organic contaminants, mostly benzoate and aminobenzoate, compared with all other examined environments. These preliminary results suggest that an anthropogenic impact on the aerobiome composition and functional profile is widespread, and pave the path to understanding the role of dust storms in disseminating microorganisms in various environments, spreading various traits, and affecting humans, livestock, plants, and ecosystem health.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/NHESS-22-3361-2022", "year": 2022, "title": "Earthquake-induced landslides in Haiti: analysis of seismotectonic and possible climatic influences", "abstract": "Abstract. First analyses of landslide distribution and triggering factors are presented for the region affected by the 14 August 2021 earthquake (Mw=7.2) in the Nippes Department, Haiti. Landslide mapping was mainly carried out by comparing pre- and post-event remote imagery (0.51 m resolution) available on Google Earth Pro and Sentinel-2 (10 m resolution) satellite images. The first covered about 50 % of the affected region (for post-event imagery and before completion of the map in January 2022), and the latter were selected to cover the entire potentially affected zone. On the basis of the completed landslide inventory, comparisons are made with catalogs compiled by others both for the August 2021 and the January 2010 seismic events, including one open inventory (by the United States Geological Survey) that was also used for further statistical analyses. Additionally, we studied the pre-2021 earthquake slope stability conditions. These comparisons show that the total number of landslides mapped for the 2021 earthquake (7091) is larger than the one recently published by another research team for the same event but slightly smaller than the number of landslides mapped by a third research team. It is also clearly smaller than the one observed by two other research teams for the 2010 earthquake (e.g., 23 567, for the open inventory). However, these apparently fewer landslides triggered in 2021 cover much wider areas of slopes (>80 km2) than those induced by the 2010 event (25 km2 considering the open inventory). A simple statistical analysis indicates that the lower number of 2021 landslides can be explained by the missing detection of the smallest landslides triggered in 2021, partly due to the lower-resolution imagery available for most of the areas affected by the recent earthquake; this is also confirmed by an inventory completeness analysis based on sizefrequency statistics. The much larger total area of landslides triggered in 2021, compared to the 2010 earthquake, can be related to different physical reasons: (a) the larger earthquake magnitude in 2021, (b) the more central location of the fault segment that ruptured in 2021 with respect to coastal zones, (c) and possible climatic preconditioning of slope instability in the 2021 affected area. These observations are supported by (1) a new pre-2021 earthquake landslide map; (2) rainfall distribution maps presented for different periods (including October 2016 when Hurricane Matthew had crossed the western part of Haiti), covering both the 2010 and 2021 affected zones; and (3) shaking intensity prediction maps.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S10661-022-10440-X", "year": 2022, "title": "Climatology and model prediction of aerosol optical properties over the Indo-Gangetic Basin in north India", "abstract": "The current research focuses on the use of different simulation techniques in the future prediction of the crucial aerosol optical properties over the highly polluted Indo-Gangetic Basin in the northern part of India. The time series model was used to make an accurate forecast of aerosol optical depth (AOD) and angstrom exponent (AE), and the statistical variability of both cases was compared in order to evaluate the effectiveness of the model (training and validation). For this, different models were used to simulate the monthly average AOD and AE over Jaipur, Kanpur and Ballia during the period from 2003 to 2018. Further, the study was aimed to construct a comparative model that will be used for time series statistical analysis of MODIS-derived AOD550 and AE412470. This will provide a more comprehensive information about the levels of AOD and AE that will exist in the future. To test the validity and applicability of the developed models, root-mean-square error (RMSE), mean absolute error (MAE), mean absolute percent error (MAPE), fractional bias (FB), and Pearson coefficient (r) were used to show adequate accuracy in model performance. From the observation, the monthly mean values of AOD and AE were found to be nearly similar at Kanpur and Ballia (0.62 and 1.26) and different at Jaipur (0.25 and 1.14). Jaipur indicates that during the pre-monsoon season, the AOD mean value was found to be highest (0.32 0.15), while Kanpur and Ballia display higher AOD mean values during the winter season (0.72 0.26 and 0.83 0.32, respectively). Among the different methods, the autoregressive integrated moving average (ARIMA) model was found to be the best-suited model for AOD prediction at Ballia based on fitted error (RMSE (0.22), MAE (0.15), MAPE (24.55), FB (0.05)) and Pearson coefficient r (0.83). However, for AE, best prediction was found at Kanpur based on RMSE (0.24), MAE (0.21), MAPE (22.54), FB (-0.09) and Pearson coefficient r (0.82).", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1520/JTE20170059", "year": 2018, "title": "Albedo estimation of finite-sized concrete specimens", "abstract": "Albedo in the context of the Urban Heat Island contributes to the environmental impact of a pavement. Measuring the pavement albedo is difficult as it depends on the size of the specimen, background interference, and variations in the incoming solar spectrum. For this study, the albedo was determined for a 1-m2 concrete slab cast with white cement containing titanium dioxide nanoparticles. The size of the exposed surface of the slab was varied using black paper. To calculate the albedo of these nonstandard specimen sizes, a new testing technique was proposed that uses an albedometer and various geometric conditions, including the exposed slab surface and measurement height. The albedo of the finite-sized concrete specimen was found to range from 0.50 to 0.55, depending on the number of unknowns assumed, with the most reasonable estimate of 0.54. The measured slab albedo from the new method was also verified using a laboratory spectrophotometer. With this proposed methodology to account for background surfaces, the albedo of laboratory-sized concrete specimens of any shape can now be easily measured at various test site locations.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "SECTION: 9\n_EPRINT: HTTPS://ONLINELIBRARY.WILEY.COM/DOI/PDF/10.1002/9781119788157.CH9\n10.1002/9781119788157.CH9", "year": 2022, "title": "Forest Fire Susceptibility Mapping by Integrating Remote Sensing and Machine Learning Algorithms", "abstract": "Forest fires are a very common in India, especially in the hilly regions of the western and northeastern Himalayas, which puts adverse impacts on the environment and society. Himachal Pradesh and Uttarakhand are the states most prone to forest fires; therefore, this research is intended to map forest fire occurrence in both states using geospatial techniques and machine learning algorithms (MLAs). To fulfill this objective, we used the meteorological data such as evapotranspiration, precipitation, temperature and wind speed data regarding aridity, elevation, slope, aspect, curvature and land use/land cover (LULC) data; and three MLAs: support vector machine (SVM), random forest (RF), and logistic regression (LR) along with an ensemble learning model were used for the modeling of susceptibility of forest fires. This produced forest fire susceptible maps that were finally validated using the global fire atlas of the NASA Earth DATA. The result showed that more than 50% of the area of Uttarakhand and Himachal Pradesh states lies under the moderate, high, and very high forest fire susceptible zones. Further, most of the low hilly and foothill regions of both the states lie under the high and very high forest fire susceptible zones. The validation of the models used was completed using the ROC curve, which showed that the area under curve (AUC) of the ROC (experimental and binormal) was highest for ensemble model, i.e. 0.923 and 0.989, respectively followed by SVM (0.89 and 0.97), RF (0.887 and 0.96), and LR (0.85 and 0.92). This indicates that, although all the models produced satisfactory results, the accuracy of the ensemble model was highest. The output of this research can be utilized for the effective mitigation of forest fires, as well as forest management in the region. Further, similar approaches may be used in other parts of the world for forest fire susceptibility mapping using additional parameters.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ATMOSRES.2022.106468", "year": 2023, "title": "Impact of Relative Humidity on the vertical distribution of aerosols over India", "abstract": "Water uptake by aerosol particles significantly changes its light-scattering characteristics, alters the physical and optical properties of aerosols. In this article, we present the effect of ambient relative humidity (RH) on the optical properties of surface and columnar aerosols under different RH conditions during different seasons over India. In particular, relation between surface RH and surface aerosol properties, surface RH and aerosol optical depth (AOD) and profile of RH on the AOD is presented. An increase in the surface aerosol scattering coefficient (scat) and total aerosol number concentration (N(d)) is observed under high humidity (50100%) condition than low humidity (030%). This is more prominent in the winter and pre-monsoon seasons. An increase in the AOD is observed as surface RH increase in all the seasons except in monsoon season where it showed an inverse relation. The profile measurements (Lidar and radiosonde) also showed a consistent increase in AOD (0-6 km) from low to high RH (0-6 km) conditions. This relationship is significant during winter followed by the post-monsoon, pre-monsoon, and monsoon seasons. An increase in AOD with RH is observed regardless of altitude in all seasons, except during the monsoon at higher altitudes (2-6 km). Our findings clearly demonstrated that during the winter and monsoon (pre- and post-monsoon) seasons, aerosols within (above) the boundary layer are more sensitive to the RH. This relationship has been tested in different surface conditions across India using CALIPSO and IMD radiosonde measurements. These measurements also confirmed an increase in AOD with increasing RH in all the regions except East Coast (EC) region. Irrespective of the region, this feature is more prominent at lower altitudes (01.5 km) during winter and higher altitudes (1.5-6 km) during other seasons. At higher altitudes, only a few regions (Central India, Indo-Gangetic Plain, and West Coast) showed an inverse relationship between AOD and RH during the monsoon and post-monsoon seasons. Further, our results illustrated the contribution of hygroscopic particles to the RH increases the AOD in a given season. This finding implies that hygroscopic growth caused by water-soluble particles in the lower troposphere can significantly alter the magnitude of aerosol radiative forcing both at the surface and at the top of the atmosphere.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.37896/SR9.10/007", "year": 2022, "title": "Long Term Study of Surface Gases Variability Trends Using Satellite Based Data at Southern Region of Rajasthan", "abstract": "In this study, we present long-term total column measurements of carbon monoxide (CO), Nitrogen dioxide (NO2), Sulfur dioxide (SO2), ozone (O3) at an urban location, Udaipur (24.59N, 73.73E, 423 m above mean sea level), in Rajasthan from January 2010 to December 2020. The long-term mean total column concentrations of CO, NO2, SO2, and O3 were 2.09 (x 10 18 mol/cm 2), 1.9 (x 10 15 mol/cm 2), 0.12 DU, and 270.4 DU, respectively. CO, NO2, and SO2 were the lowest during the monsoon season, whereas O3 concentration peaked during summer. The former could be attributed mainly to the near-surface anthropogenic sources (e.g. automobiles, residential cooking, agricultural land-clearing, and biomass burning) and increased humidity. In contrast, the latter was clearly due to enhanced chemical production of O3 during the pre-monsoon (i.e. summer) season. The mean lowest concentration of all gases was observed during the post-monsoon season due to efficient wet scavenging by precipitation. The averaged decadally and multi-annual patterns showed mixed trends, declining in 2020 due to movement restriction. Total column concentrations of CO, NO2, SO2, and O3 register 1.8%, 6.9%, 7.7%, and 1.3% enhancement since 2010 in the Udaipur region. From the interannual comparison, the column CO and O3 concentrations have increased by 1.5% and 3.5%, respectively, from 2019, despite the imposed movement restrictions. Upon the investigation of atmospheric parameters, average Temperatures are linked to the boundary layer height variability. The correlation between CO, NO2, SO2 and O3 was average. Contrarily, O3 depicted a reverse pattern with the highest concentrations during summer and monsoon and lowest in the winters. The mean wind speeds, PBL height and RH at Udaipur during 2010-2020 were five m/s, 820 m, and 38%, respectively. O3 followed a positive correlation with Temperature, the negative with CO, NO2 and SO2.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/D14100808", "year": 2022, "title": "Variation in Fish Abundance, Diversity and Assemblage Structure in Seagrass Meadows across the Atlanto-Mediterranean Province", "abstract": "Seagrasses worldwide provide key habitats for fish assemblages. Biogeographical disparities in ocean climate conditions and seasonal regimes are well-known drivers of the spatial and temporal variation in seagrass structure, with potential effects on associated fish assemblages. Whether taxonomically disparate fish assemblages support a similar range of ecological functions remains poorly tested in seagrass ecosystems. In this study, we examined variation in the abundance, diversity (from a taxonomic and functional perspective), and assemblage structure of fish community inhabiting nine meadows of the seagrass Cymodocea nodosa across three regions in the Mediterranean (Mallorca and Alicante) and the adjacent Atlantic (Gran Canaria), and identified which attributes typifying the structure of meadows, and large-scale variability in ocean climate, contributed most to explaining such ecological variation. Despite a similar total number of species between Mallorca and Gran Canaria, the latter region had more taxonomically and functionally diverse fish assemblages relative to the western Mediterranean regions, which translated into differences in multivariate assemblage structure. While variation in the abundance of the most conspicuous fish species was largely explained by variation in seagrass structural descriptors, most variation in diversity was accounted for by a descriptor of ocean climate (mean seasonal SST), operating at regional scales. Variation in fish assemblage structure was, to a lesser extent, also explained by local variability in seagrass structure. Beyond climatic drivers, our results suggest that lower temporal variability in the canopy structure of C. nodosa meadows in Gran Canaria provides a more consistent source of food and protection for associated fish assemblages, which likely enhances the more abundant and diverse fish assemblages there.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/URBANSCI6040070", "year": 2022, "title": "Relationship between Lightning and Aerosol Optical Depth over the Uttarakhand Region in India: Thermodynamic Perspective", "abstract": "The current study is mainly focused on the monthly variation in the lightning flash rate (LFR) and related thermodynamic parameters using the data for the years 20002013, and the trend of lightning variation is explored. Lightning data are used from a lightning imaging sensor (LIS) and an optical transient detector (OTP) boarded on the tropical rainfall measuring mission (TRMM). Additionally, aerosol optical depth (AOD) data at 550 nm for the same period were considered from a Moderate Resolution Imaging Spectroradiometer (MODIS). The assessment of lightning and AOD using monthly data makes it difficult to study seasonal contributions, and higher-resolution (hourly) data may be more appropriate, but unfortunately, no data were available with a higher resolution than monthly. The dependency of LFR is also investigated using thermodynamic/dynamic parameters. The LFR shows a moderate correlation with a correlation coefficient of 0.56, 0.62, and 0.63 for AOD, CAPE, and vertical velocity, respectively. The increasing AOD in the pre-monsoon season is associated with higher lightning flash rates over this region. The possible sources of aerosols that cause an increase in lightning activities are identified from the classification of aerosols based on the characteristic values of the AOD and the Angstrom exponent. The thermodynamic relation of the Product of Bowen ratio with the sum of the precipitation rate and evaporation rate has been used as a proxy to evaluate the lightning flash rate density over Srinagar, Uttarakhand region (78.55 E79.05 E, 29.97 N30.47 N), with nine models from the Coupled Model Inter-comparison Project-Phase 5 (CMIP5). The model-simulated LFR has also been used for the projection of lightning in the late 21st century, and the projected LFR over the study area shows a 7.41% increase during the (20792088) period as compared to the historic period (19962005). The results of the study region indicate caution in using any single climate variable as a proxy for projecting a change in the lightningclimate relationships in the scenario of global warming.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/LOM3.10522", "year": 2022, "title": "Multiple sampling methods to develop indices of mid-trophic levels abundance in open ocean ecosystems", "abstract": "Mid-trophic level (MTL) organisms play a key role in the sub-Antarctic ecosystem food web, linking primary producers and tertiary consumers transferring energy across trophic levels. In this region, the relative abundance of MTLs has been monitored using single-frequency acoustic data collected opportunistically in a time series of trawl surveys carried out in the austral late spring/early summer. To advance this approach, we developed a methodology that enabled us to disaggregate multifrequency acoustic data into three different MTL groups to assess their temporal and spatial patterns: mesopelagic fish, gelatinous zooplankton (excluding pyrosomes), and euphausiids. We used acoustic data and biological sampling information collected with two midwater trawl nets from a dedicated voyage, to train a classification tree algorithm. We complemented these data with footage from an in-trawl camera system that gave us new insights on vertical distribution and presence of pelagic taxa. The testing dataset used to implement our classification algorithm was a time series of acoustic data from the sub-Antarctic trawl survey. This approach was successful at disaggregating acoustic data and provided useful information to study the relative abundance and temporal and spatial patterns of pelagic taxa. Our analysis revealed the presence of dense shallow layers of gelatinous zooplankton which showed a statistically significant increasing trend over the time series. Although we were unable to detect pyrosomes acoustically, we encountered large biovolumes of these organisms during our biological sampling, which was supported by the in-trawl camera system.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.JMARSYS.2015.02.006", "year": 2015, "title": "Organic carbon inputs to the sea bottom of the Mallorca continental slope", "abstract": "To assess the origin and degradation state of the organic particles sinking towards the sea bottom of the Mallorca continental slope, the major inorganic and organic components of the total mass flux and its biochemical composition (in terms of protein, carbohydrate, lipid and phytopigment contents) have been analysed. Two instrumented lines were deployed at the western (Soller station, Balearic sub-basin) and southern (Cabrera station, Algerian sub-basin) slopes of Mallorca Island, 900m depth from November 2009 to January 2011. The two locations are characterized by putatively different environmental settings. Settled material at Soller station has higher lithogenic contents when compared with the Cabrera one. Such difference can be explained by the synergistic presence in the Soller station of large inputs of resuspended material due to the mesoscale variability of the Balearic current and the impact of bottom trapped waves. On the other hand, at the Cabrera station sinking particles are characterized by OM and opal percentages higher than those recorded at the Soller station. This result points out that organic particles reaching the sea floor at the Cabrera station have a pre-eminent pelagic origin. Based on analyses of the C and N stable isotopes of the sinking material, our results also highlight that, overall, the OM reaching the sea floor at the Mallorca slope is mostly of marine origin. In general, the OM settled at the Soller station has a higher nutritional value than that at the Cabrera one. Such a difference, occurring across a relatively reduced spatial scale, let us hypothesizing that the nutritionally richer particles descending in the Cabrera station are exposed to a less energetic environment than that in the Soller setting. This would lead to higher settling velocity of particles in the Soller setting which in turn would result in lower degradation rates of particles during their descent towards the sea bottom.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5721/EUJRS20154826", "year": 2015, "title": "Variability of satellite-derived sea surface height anomaly, and its relationship with Bigeye tuna (Thunnus obesus) catch in the Eastern Indian Ocean", "abstract": "We analyzed the variability of sea surface height anomaly (SSHA), and its relationship with Bigeye tuna catch in the eastern Indian Ocean (EIO) off of Java Island (Indonesia). Both time series of SSHA and Bigeye tuna HR show dominant signals corresponding to the annual and inter-annual variability. During the southeast monsoon the wind blows along southern coast of Java and produces coastal upwelling. This causes sea level to drop due to an offshore Ekman transport, and thermocline becomes shallower. During El Nino and Indian Ocean Dipole (IOD) positive phase, upwelling is more intense and a large cold eddy forms in the EIO off Java. Generally, Bigeye tuna HR tends to increase during upwelling seasons and becomes even higher during El Nino and the positive phase of the IOD. The increased Bigeye tuna HR during the southeast monsoon, El Nino and the IOD positive phase can be attributed to the shallower thermocline depth and the enhancement of biological productivity due to development of eddies and strong upwelling in the EIO. The spatial distribution of SSHA indicates that Bigeye tuna catches are abundant in the frontal regions between cold and warm eddies.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/ATMOS6081211", "year": 2015, "title": "UV Irradiance Enhancements by Scattering of Solar Radiation from Clouds", "abstract": "Scattering of solar radiation by clouds can reduce or enhance solar global irradiance compared to cloudless-sky irradiance at the Earths surface. Cloud effects to global irradiance can be described by Cloud Modification Factors (CMF). Depending on strength and duration, irradiance enhancements affect the energy balance of the surface and gain of solar power for electric energy generation. In the ultraviolet region, they increase the risk for damage to living organisms. Wavelength-dependent CMFs have been shown to reach 1.5 even in the UV-B region at low altitudes. Ground-based solar radiation measurements in the high Andes region at altitudes up to 5917 m a.s.l showed cloud-induced irradiance enhancements. While UV-A enhancements were explained by cloud scattering, both radiation scattering from clouds and Negative Ozone Anomalies (NOA) have been discussed to have caused short-time enhancement of UV-B irradiance. Based on scenarios using published CMF and additional spectroradiometric measurements at a low-altitude site, the contribution of cloud scattering to the UV-B irradiance enhancement in the Andes region has been estimated. The range of UV index estimates converted from measured UV-B and UV-A irradiance and modeled cloudless-sky ratios UV-B/erythemal UV is compatible with an earlier estimate of an extreme UV index value of 43 derived for the high Andes.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S12517-014-1578-5", "year": 2015, "title": "Use of multitemporal satellite images to find some evidence for glacier changes in the Haft-Khan glacier, Iran", "abstract": "Present paper reports on the Haft-Khan glacier clean-ice area change between 1955 and 2010 based on several high to medium spatial resolution satellite images. Present glacier is heavily covered by debris (referred as supra-glacial debris cover). Because of these covers, mapping the actual glacier area with reasonable accuracy is impossible. Therefore, the changes of clean-ice regions have been detected as a good evidence for glacier change. For the detection of these changes, nine high to medium spatial resolution satellite images were selected. Although these images are the best available satellite images in Haft-Khan Glacier (to avoid any misclassification), but the possible changes in perennial snow fields cannot be separated from the clean-ice area changes. It means that some of the obtained changes may also be related to the changes in perennial snow fields not the absolute change of clean-ice regions. The object-oriented classification approach has been used to estimate the clean-ice glaciated areas. Object-oriented classification method takes into account the shapes of the features along with their spectral patterns. In the last decades, advantages in computer technologies have led to the development of object-based image analysis; an image classification technique that can be seen as an alternative to the common pixel-based image analysis and manual digitization. Results revealed that debris-free areas of Haft-Khan glacier shrank since 2010 with an overall area reduction of about 58 5 %. Although the general trend is clean-ice area reduction, some limited area gain has been observed over the period of 20032010. During the 19922000, the maximum reduction in the clean-ice area was observed (0.13 0.009 km2 a1). However, during the 20032010, the areas of clean-ice regions have steadily increased. Fractional snow cover (FSC) change during the last 34 years (19792013) revealed that precipitation during the accumulation period (from November to May of the following year) decreased significantly, reducing the snowfall contribution to mean balance. This is the main reason for the clean-ice area shrinkage in the Haft-Khan glacier.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.CSR.2015.08.026", "year": 2015, "title": "Time series analyses reveal environmental and fisheries controls on Atlantic horse mackerel (Trachurus trachurus) catch rates", "abstract": "Time-series models (Dynamic factorial analyses and; Min/max autocorrelation factor analysis) were used to explore the relative influences of environmental variables and fishing pressure of trawl, seine and artisanal fleets on catch rates on Trachurus trachurus in ICES IXa sub-divisions (IXaCN-North coast; IXa- CS-South coast; IXaS-Algarve, South coast, Algarve). Fishing effort influenced catch rates in all areas with a 2 year lag and fishing pressure for each area was related to specific fleet sectors effort. In IXaCN, winter upwelling (spawning peak) and both summer northerly wind and wind magnitude (outside of the spawning peak) were strongly correlated with catch rates. In IXaCS summer/autumn westerly winds were related with catch rates. Northerly winds in spring, upwelling and SST (winter and autumn) were related with catch rates in IXaS-Algarve. For species with a long spawning season such as horse mackerel, seasonal analyses at broad regional scales can detract from a better understanding of variability in short term sub-stock catch rates. Favorable environmental conditions, even during seasons with low spawning activity can positively affect catch rates. Ignoring the role of regional oceanographic features on the spatial distribution of the sub-stocks when analysing variability in catch rates can lead to poor inferences about the productivity of the populations.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5094/APR.2015.063", "year": 2015, "title": "Spatiotemporal variability in dust observed over the Sinkiang and Inner Mongolia regions of Northern China", "abstract": "This study presents a detailed analysis of the spatiotemporal variability in dust observed over Sinkiang and Inner Mongolia in Northern China from 2005 to 2008. The relationships between airborne dust (observed by OMIAI and MODISAOD), the normalized difference vegetation index (NDVI), monthly total precipitation (MTP) and surface wind speed (SWS) are investigated. The results show that the spatial distribution of airborne dust distinctly decreases from west to east across Northern China; this pattern is opposite to that of the NDVI and MTP. Both Sinkiang and Inner Mongolia experience high amounts of airborne dust in spring, with the highest values in April. The two regions also had different dust variabilities. In Sinkiang, three major dust regions were identified, with airborne dust mainly distributed in regions with NDVI values between 0 and 0.1, SWS values between 2 and 5m/s, and a MTP of less than 5mm. In addition, the temporal variation in airborne dust exhibits both positive and negative correlations with the NDVI, MTP and SWS. However, over Inner Mongolia, five highdust regions were confirmed, with airborne dust generally distributed in the areas with NDVI values between 0 and 0.4, SWS values between 3 and 6m/s, and a MTP of less than 10mm. The time series of airborne dust is negatively correlated with the NDVI and MTP but strongly and positively correlated with the SWS. In addition, the temporal pattern of the AOD in Sinkiang is essentially controlled by dust activity, whereas it may be influenced by anthropogenic emissions in Inner Mongolia. Overall, the spatiotemporal variabilities in dust over Sinkiang and Inner Mongolia are not identical, although both regions are important sources of dust in East Asia.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2015.04.026", "year": 2015, "title": "Spatiotemporal coherence of mean and extreme aerosol particle events over eastern North America as observed from satellite", "abstract": "Quantifying spatiotemporal scales of coherence and variability of aerosol particle properties provides (i) metrics for evaluating observational data sets and model simulations, (ii) inferences regarding dominant causes of variability, and (iii) information that is necessary to determine their climate forcing and air quality impacts. Accordingly, analyses of columnar aerosol optical depth (AOD) and Angstrom exponent (AE) from the MODerate resolution Imaging Spectroradiometer (MODIS) on the Aqua and Terra satellites, and AErosol RObotic NETwork (AERONET) stations are used to evaluate the spatially averaged (Level-3) MODIS products, and to characterize the spatiotemporal scales of variability (and coherence) of aerosol particles over eastern North America (20002013). Results show a high degree of consistency in AOD retrievals from the different data sets but larger discrepancies in AE estimates, highest mean AOD and lowest day-to-day variability during the summer, and largest scales of spatial coherence in summer and fall. Consistent with the scales of spatial coherence from MODIS data, in both data sets power spectra indicate AOD variability is manifest primarily on synoptic and annual time scales. Conversely, AE variability in MODIS data is primarily focused on seasonal, semiannual, and annual time scales, and there is an additional mode of AE variability at 30 days in the AERONET measurements. The frequency of co-occurrence of extreme AOD values (>local 90th percentile) decreases to below 50% at 150 km from a central grid cell, but is above that expected by random chance over almost all of eastern North America, indicating supra-regional scale extreme events.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.EPSL.2015.04.015", "year": 2015, "title": "A dual-tracer approach to estimate upwelling velocity in coastal Southern California", "abstract": "The distribution of the cosmogenic radionuclide 7Be (t1/2=53d) in the surface ocean has previously been used to estimate upwelling velocity in the open ocean. However, the loss of 7Be to particle export has limited this approach in high particle density environments like the continental margins. In this study, we combine a mass balance of 7Be with a 234Th budget in the surface ocean to constrain the loss of 7Be to particle sinking at the San Pedro Ocean Time-series (SPOT) in the inner Southern California Bight during spring 2013. Upwelling velocities (all in m d1) determined from the 7Be mass balance were observed to increase from 0.50.6 in January to 2.51.3 in May, then decrease to 1.20.5 in June. These results agree within uncertainty with upwelling velocities derived from the monthly Bakun Upwelling Index, which ranged from 0.1 to 2.8 m d1, supporting the pressure-field-based approach. Evidence from a heat budget and the nutrient distribution over the course of the study supports that the upwelling signal at SPOT (20 km offshore) is not transported from coastal upwelling near shore, but instead is dominantly a local signal, likely driven by wind-stress curl.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2014JD023005", "year": 2015, "title": "Validation of modeled daily erythemal exposure along tropical and subtropical shipping routes by ship-based and satellite-based measurements", "abstract": "AbstractThe Personal ERythemal EXposure (PEREX) model for seafarers working on decks of vessels has been developed to be used for retrospective estimates of personal occupational erythemal exposure in dependence of work profile, time period, and sea route. Extremely high UV index values up to 22 and daily erythemal exposure up to 89 standard erythemal dose have been derived from ship-based measurements in tropical oceans. Worldwide climatological maps of daily solar erythemal exposure derived from 10 year (20042013) hourly grid point radiative transfer model calculations for both cloudless sky and cloudy sky serve as the database of PEREX. The PEREX database is compared with ship-based measurements taken along four routes of merchant vessels, continuous UV radiation measurements taken on the research vessel Meteor on its mainly tropical and subtropical routes for 2 years, daily cloudless-sky erythemal exposure derived from 10 min LibRadtran radiative transfer model calculations, and 2 years of satellite-based erythemal exposure data of the Ozone Monitoring Instrument on the Aura satellite along the ship routes. Systematic differences between PEREX model data, ship-based data, and satellite-based daily erythemal exposure for all-sky conditions are only 1 to 3%, while short-term variations of cloudiness result in standard deviations of differences around 30%. Measured ratios between cloudless-sky erythemal radiation at vertical to horizontal incidence decrease with decreasing solar zenith angle, while clouds flatten their diurnal course.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1134/S0001437015060065", "year": 2015, "title": "Vortex dynamics in the southeastern Baltic Sea from satellite radar data", "abstract": "The analysis of radar satellite images shows that vortex dipoles are a typical element of the water circulation in the southeastern part of the Baltic Sea. The wide range of spatial dimensions of observed vortices (from approximately 2 to 25 km) corresponds to mesoscale and submesoscale vortex formations (signifying whether the diameter is respectively larger or smaller than the baroclinic Rossby radius of deformation, equal to 56 km). Vortex dipoles typical for different areas and their spatial characteristics are considered. These areas were the Hel Spit, the Taran Cape, the central part of the Gulf of Gdansk and the area northward of the Gulf. It is shown that the mesoscale vortex dipoles and the associated jets condition horizontal water exchange in an area comparable with the size of the considered water area. The differences in the appearance of the cyclonic and anticyclonic components of vortex dipoles revealed in satellite radar images are discussed.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00703-014-0352-2", "year": 2015, "title": "Variability in aerosol optical properties and radiative forcing over Gorongosa (18.97oS, 34.35oE) in Mozambique", "abstract": "This paper reports the observational results of aerosol optical, microphysical and radiative characteristics for the time measured over Gorongosa (18.97oS, 34.35oE, 30 m asl) in Mozambique using a ground-based AERONET sun-sky radiometer. In the present study, the data recorded during the period JulyDecember, 2012 have been used and particular attention was paid to show how aerosol loading evolves during the biomass burning season (spring) including pre- and post-months. The results reveal that the monthly mean aerosol optical depth (AOD) at 500 nm was high (low) with 0.64 0.34 (0.20 0.06) in September (November), while the Angstrom Exponent (AE) (440870) decreased, except September (1.56 0.26) due to increase in the fine-mode aerosol concentration produced from biomass burning. The volume size distribution (VSD) has bimodal lognormal structure and has fine-mode (coarse) maximum at a radius of 0.15 m (3.0 m) in September (December). The single scattering albedo (SSA) decreases with wavelength from July to October and almost stable in November and December. The imaginary (Im) refractive index (RI) showed a strong evidence of black carbon aerosol origin during the biomass burning months. Aerosol radiative forcing (ARF) computed from SBDART model shows large negative values at the surface (89.22 W m2) and at the top (22.36 W m2), with a higher value of atmospheric forcing (+66.87 W m2) resulting in average tropospheric heating rate of 1.88 K day1 for the study period. Further, the comparison shows good agreement between the ARFs at the top and bottom of the atmosphere derived from AERONET to SBDART.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ASR-12-147-2015", "year": 2015, "title": "UV and global irradiance measurements and analysis during the Marsaxlokk (Malta) campaign", "abstract": "Abstract. A solar radiation measurement campaign was performed in the south-eastern village of Marsaxlokk (3550' N; 1433' E; 10 m a.s.l), Malta, between 15 May and 15 October 2012. Erythemal solar radiation data (from a UVB-1 pyranometer), and total horizontal solar radiation (global and diffuse components) from two CM21 pyranometer were recorded. A comparison of atmospheric compounds from ground measurements and satellites shows that TOC (total ozone column) data from the Ozone Monitoring Instrument OMI, TOMS and DOAS algorithms correlate well with ground-based recorded data. The water vapour column and the aerosol optical depth at 550 nm show a significant correlation at the confidence level of 99 %. Parametric models for evaluating the solar UV erythemal (UVER), global (G) and diffuse (D) horizontal irradiances are calibrated, from which aerosol effects on solar irradiance are evaluated using the Aerosol Modification Factor (AMF). The AMFUVER values are lower than AMFG, indicating a greater aerosol effect on UVER than on global solar irradiance. In this campaign, several dust event trajectories are identified by means of the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and by synoptic conditions for characterizing desert dust events. Hence, changes in the UV index due to atmospheric aerosols are described.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.JAG.2015.01.008", "year": 2015, "title": "Using remote sensing to monitor the influence of river discharge on watershed outlets and adjacent coral Reefs: Magdalena River and Rosario Islands, Colombia", "abstract": "Worldwide, coral reef ecosystems are being increasingly threatened by sediments loads from river discharges, which in turn are influenced by changing rainfall patterns due to climate change and by growing human activity in their watersheds. In this case study, we explored the applicability of using remote sensing (RS) technology to estimate and monitor the relationship between water quality at the coral reefs around the Rosario Islands, in the Caribbean Sea, and the rainfall patterns in the Magdalena River watershed. From the Moderate Resolution Imaging Spectroradiometer (MODIS), this study used the water surface reflectance product (MOD09GQ) to estimate water surface reflectance as a proxy for sediment concentration and the land cover product (MCD12Q1 V51) to characterize land cover of the watershed. Rainfall was estimated by using the 3B43 V7 product from the Tropical Rainforest Measuring Mission (TRMM). For the first trimester of each year, we investigated the inter-annual temporal variation in water surface reflectance at the Rosario Islands and at the three main mouths of the Magdalena River watershed. No increasing or decreasing trends of water surface reflectance were detected for any of the sites for the study period 20012014 (p>0.05) but significant correlations were detected among the trends of each site at the watershed mouths (r=0.570.90, p<0.05) and between them and the inter-annual variation in rainfall on the watershed (r=0.630.67, p<0.05). Those trimesters with above-normal water surface reflectance at the mouths and above-normal rainfall at the watershed coincided with La Nina conditions while the opposite was the case during El Nino conditions. Although, a preliminary analysis of inter-annual land cover trends found only cropland cover in the watershed to be significantly correlated with water surface reflectance at two of the watershed mouths (r=0.58 and 0.63, p<0.05), the validation analysis draw only a 40.7% of accuracy in this land cover classification. This requires further analysis to confirm the impact of the cropland on the water quality at the watershed outlets. Spatial analysis with MOD09GQ imagery detected the overpass of river plumes from Barbacoas Bay over the Rosario Islands waters.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.3390/CLI3010193", "year": 2015, "title": "Urban-Induced Mechanisms for an Extreme Rainfall Event in Beijing China: A Satellite Perspective", "abstract": "Using 1 km satellite remote sensing observations, this paper examines the clouds, aerosols, water vapor and surface skin temperature over Beijing to understand the possible urban system contributions to the extreme rainfall event on 21 July 2012 (i.e., 721 event). Remote sensing measurements, with the advantage of high spatial resolution and coverage, reveal three key urban-related mechanisms: (a) the urban heat island effect (UHI) resulted in strong surface convection and high level cloud cover over Beijing; (b) urban aerosol amount peaked before the rainfall, which seeded the clouds and invigorated precipitation; and (c) urban tall buildings provided additional lift for the air mass and provided heat at the underlying boundary to keep the rainfall system alive for a long duration precipitation (>10 hours). With the existing rainfall system moving from the northwest and abundant water vapor was transported from the southeast into Beijing, the urban canyon-lifting, aerosol, and UHI effects all enhanced this extreme rainfall event. This work proves that urban system is responsible, at least partly, for urban rainfall extremes and thus should be considered for urban extreme rainfall prediction in the future.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3354/MEPS11288", "year": 2015, "title": "Uncovering the trophic relationship between Themisto gaudichaudii and Salpa thompsoni in the Antarctic Polar Frontal Zone", "abstract": "Trophic dynamics of 2 abundant macrozooplankton species Salpa thompsoni and Themisto gaudichaudii were studied during the austral summer at 2 locations near the Antarctic Polar Front with contrasting low and high chlorophyll a (chl a) concentrations. Compound-specific stable isotope analysis, complemented by gut content and bulk isotope analyses, were used to investigate trophic interactions between species, and to assess their trophic positions in the pelagic food web. The results of the compound-specific stable isotope analysis placed S. thompsoni at the second trophic level and approx. 1 trophic level below T. gaudichaudii. Two forms of T. gaudichaudii appeared to feed at different trophic levels, with T. gaudichaudii bispinosa feeding at a higher trophic level (~3.3) than T. gaudichaudii compressa (~2.8). Isotope data coupled with gut content analysis indicated a regular consumption of salps in both areas, although a higher contribution of gelatinous prey was encountered in a chl a poor area. The food web baseline values (bulk 13C) varied regionally, highlighting 2 independent food webs albeit with a similar trophic structure. Overall, our findings suggested that in areas where S. thompsoni is highly abundant, T. gaudichaudii may be a significant predator of this species.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSRES.2015.06.021", "year": 2015, "title": "Uncertainties in anthropogenic aerosol concentrations and direct radiative forcing induced by emission inventories in eastern China", "abstract": "This study quantified the uncertainties in concentrations and direct radiative forcing of anthropogenic aerosols due to emissions in eastern China using a global chemistryaerosolclimate model. The emission inventories included three global inventories, ACCMIP (Atmospheric Chemistry & Climate Model Intercomparison Project), EDGAR-HTAP (Emission Database for Global Atmospheric Research for Hemispheric Transport of Air Pollution), and EDGAR Version 4.2, and one regional INTEX-B (Intercontinental Chemical Transport ExperimentPhase B) inventory. The uncertainties (a percentage of the standard deviation divided by the mean value across the four inventories) in the regional surface-layer aerosol concentrations due to emissions were 3.9% in sulfate, 40.0% in nitrate, 18.4% in ammonium, 11.1% in POA, 16.7% in SOA and 15.4% in BC. Compared with the ACCMIP model results based on a uniform emission inventory, the impacts of emissions were smaller. One exception is the regional surface-layer nitrate concentration, which had comparable uncertainties due to the emissions (40.0%) and the models (43.8%) because of the complex nitrate chemistry and the highly uncertain NH3 emission. The mean regional aerosol direct forcing at the top of the atmosphere between 1850 and 2006 was 3.6Wm2 under all-sky conditions and was enhanced up to 3.83Wm2 after the model assimilated the MODIS find-mode aerosol optical depth (AOD). The impact of the assimilation of absorption AOD is discussed. The uncertainties in aerosol direct forcing were smaller than those of the ACCMIP inter-model results, but still significant. An accurate emission inventory is essential for quantifying the role of aerosols in regional climate.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11356-014-3561-9", "year": 2015, "title": "Time series model prediction and trend variability of aerosol optical depth over coal mines in India", "abstract": "A study of the assessment and management of air quality was carried out at 11 coal mines in India. Long-term observations (about 13 years, March 2000December 2012) and modeling of aerosol loading over coal mines in India are analyzed in the present study. In this respect, the Box-Jenkins popular autoregressive integrated moving average (ARIMA) model was applied to simulate the monthly mean Terra Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol optical depth (AOD550 nm) over 11 sites in the coal mines region. The ARIMA model was found as the most suitable model with least normalized Bayesian information criterion (BIC) and root mean square error and high value of R2. Estimation was done with the Ljung-Box test. Finally, a forecast for a 3-year period from January 2013 to December 2015 was calculated which showed that the model forecasted values are following the observed trend quite well over all mining areas in India. The average values of AOD for the next 3 years (20132015) at all sites are found to be 0.575 0.13 (Raniganj), 0.452 0.12 (Jharia), 0.339 0.13 (Bokaro), 0.280 0.09 (Bishrampur), 0.353 0.13 (Korba), 0.308 0.08 (Talcher), 0.370 0.11 (Wardha), 0.35 0.10 (Adilabad), 0.325 0.09 (Warangal), 0.467 0.09 (Godavari Valley), and 0.236 0.07 (Cuddapah), respectively. In addition, long-term lowest monthly mean AOD550 values are observed over Bishrampur followed by Cuddapah, Talcher, Warangal, Adilabad, Korba, Wardha, Godavari Valley, Jharia, and Raniganj. Raniganj and Jharia exhibit the highest AOD values due to opencast mines and extensive mining activities as well as a large number of coal fires. Similarly, the highest AOD values are observed during the monsoon season among all four seasons over all the mining sites. Raniganj exhibits the highest AOD value at all seasons and at all sites. In contrast, the lowest seasonal AOD values are observed during the post-monsoon season over Raniganj, Talcher, Wardha, Adilabad, Warangal, and Godavari Valley. Similarly, over Jharia, Bokaro, Bishrampur, Korba, and Cuddapah, the lowest AOD values are found in the winter season. Increasing trends in AOD550 have been observed over Raniganj, Bokaro, Bishrampur, Korba, Talcher, and Wardha as well as over Adilabad and Godavari Valley, which is in agreement with previous works. Negative or decreasing AOD trend is found only over Jharia, Warangal, and Cuddapah without being statistically significant. Seasonal trends in AODs have also been studied in the present paper.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-15-13269-2015", "year": 2015, "title": "The role of semi-volatile organic compounds in the mesoscale evolution of biomass burning aerosol: a modeling case study of the 2010 mega-fire event in Russia", "abstract": "Abstract. Chemistry transport models (CTMs) are an indispensable tool for studying and predicting atmospheric and climate effects associated with carbonaceous aerosol from open biomass burning (BB); this type of aerosol is known to contribute significantly to both global radiative forcing and to episodes of air pollution in regions affected by wildfires. Improving model performance requires systematic comparison of simulation results with measurements of BB aerosol and elucidation of possible reasons for discrepancies between them, which, by default, are frequently attributed in the literature to uncertainties in emission data. Based on published laboratory data on the atmospheric evolution of BB aerosol and using the volatility basis set (VBS) framework for organic aerosol modeling, we examined the importance of taking gas-particle partitioning and oxidation of semi-volatile organic compounds (SVOCs) into account in simulations of the mesoscale evolution of smoke plumes from intense wildfires that occurred in western Russia in 2010. Biomass burning emissions of primary aerosol components were constrained with PM10 and CO data from the air pollution monitoring network in the Moscow region. The results of the simulations performed with the CHIMERE CTM were evaluated by considering, in particular, the ratio of smoke-related enhancements in PM10 and CO concentrations (PM10 and CO) measured in Finland (in the city of Kuopio), nearly 1000 km downstream of the fire emission sources. It is found that while the simulations based on a \"conventional\" approach to BB aerosol modeling (disregarding oxidation of SVOCs and assuming organic aerosol material to be non-volatile) strongly underestimated values of PM10/CO observed in Kuopio (by a factor of 2), employing the \"advanced\" representation of atmospheric processing of organic aerosol material resulted in bringing the simulations to a much closer agreement with the ground measurements. Furthermore, taking gas-particle partitioning and oxidation of SVOCs into account is found to result in a major improvement of the agreement of simulations and satellite measurements of aerosol optical depth, as well as in considerable changes in predicted aerosol composition and top-down BB aerosol emission estimates derived from AOD measurements.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/ACP-15-12231-2015", "year": 2015, "title": "The radiative impact of desert dust on orographic rain in the CevennesVivarais area: a case study from HyMeX", "abstract": "Abstract. The study is focused on Intensive Observation Period (IOP) 14 of the Hydrological Cycle in the Mediterranean Experiment first Special Observing Period (HyMeX SOP 1) that took place from 17 to 19 October 2012 and was dedicated to the study of orographic rain in the CevennesVivarais (CV) target area. During this IOP a dense dust plume originating from northern Africa (the Maghreb and Sahara) was observed to be transported over the Balearic Islands towards the south of France. The plume was characterized by an aerosol optical depth between 0.2 and 0.8 at 550 nm, highly variable in time and space over the western Mediterranean Basin. The impact of this dust plume, the biggest event observed during the 2-month-long HyMeX SOP 1, on the precipitation over the CV area has been analyzed using high-resolution simulations from the convection permitting mesoscale model Meso-NH (mesoscale non-hydrostatic model) validated against measurements obtained from numerous instruments deployed specifically during SOP 1 (ground-based/airborne water vapor and aerosol lidars, airborne microphysics probes) as well as space-borne aerosol products. The 4-day simulation reproduced realistically the temporal and spatial variability (including the vertical distribution) of the dust. The dust radiative impact led to an average 0.6 K heating at the altitude of the dust layer in the CV area (and up to +3 K locally) and an average 100 J kg1 increase of most unstable convective available potential energy (and up to +900 J kg1 locally) with respect to a simulation without prescribed dust aerosols. The rainfall amounts and location were only marginally affected by the dust radiative effect, even after 4 days of simulation. The transient nature of this radiative effect in dynamical environments such as those found in the vicinity of heavy precipitation events in the Mediterranean is not sufficient to impact 24 h of accumulated rainfall in the dust simulation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSRES.2014.10.004", "year": 2015, "title": "The influence of Sardinia on Corsican rainfall in the western Mediterranean Sea: A numerical sensitivity study", "abstract": "The interaction of orographic effects and moisture availability is of high importance to the\nprecipitation amount and distribution in the western Mediterranean and neighboring land\nsurfaces. In particular, the forecast of heavy precipitation events is still a challenge for operational\nweather forecast models. In this study, the thermal and dynamical interactions between the two\nneighboring islands of Corsica and Sardinia in the western Mediterranean Sea are investigated\nusing the COnsortium for Small-scale MOdeling (COSMO) model. Six cases with different synoptic\nconditions are analyzed and the dependance of the Corsican rainfall on the presence and terrain\ncharacteristics of Sardinia is investigated. Besides a reference run with standard model orography,\nsensitivity runs with removed and flat island of Sardinia are performed. The numerical results\nshow that the daily precipitation amount over Corsica can increase by up to 220% of the amount\nfrom the reference run. Whereas most of the sensitivity runs show a decrease of the precipitation\namount under strong synoptic forcing, there is no systematic relationship on days with weak\nsynoptic forcing. The differences in the precipitation amount are induced by (i) missing deviation\nor missing blocking of the southerly flow by Sardinia and (ii) by the influence of cold pools\ngenerated by deep convection over Sardinia. These differences can be attributed to changes of\nlow-level convergence and moisture/heat content and their effect on thermodynamic parameters,\nlike convective available potential energy or convective inhibition. Furthermore, the position and\ntranslation speed of frontal systems over Corsica on days with strong synoptic forcing also depend\non the Sardinian orography. These results demonstrate the high sensitivity of numerical weather\nprediction to the interaction of neighboring mountainous islands.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2014JD022954", "year": 2015, "title": "The GAW-PFR aerosol optical depth network: The 20082013 time series at Cape Point Station, South Africa", "abstract": "AbstractA ground-based aerosol optical depth (AOD) climatology is presented for Cape Point (CPT) station, South Africa, for the 20082013 period. CPT is part of the Global Atmosphere WatchPrecision Filter Radiometer network which conducts long-term AOD measurements at remote background sites. AOD ( = 500 nm) and Angstrom exponent (368 to 862 nm; 368862) averages for the entire period were 0.059 and 0.68, displaying only a weak seasonality. Based on an established method for air mass classification using the in situ wind direction and 222Rn concentration, the following four air mass types were used to further investigate AOD: background marine, marine, mixed, and continental. AOD was similar for all types, but 368862 was distinctly lower (0.43) for background marine and higher (1.07) for continental air masses, illustrating the presence of coarse mode and anthropogenic aerosols, respectively. Trajectory cluster analysis of 5 day back trajectories confirmed/augmented this classification. AOD for background marine and marine air mass types were consistent with ship-based (Maritime Aerosol Network) and island (AErosol RObotic NETwork) measurements, suggesting that CPT is a suitable site to monitor pristine conditions in the South Atlantic and Southern Oceans when 222Rn concentrations are < 100 mBq m3.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00703-014-0343-3", "year": 2015, "title": "The footprints of Saharan air layer and lightning on the formation of tropical depressions over the eastern Atlantic Ocean", "abstract": "The roles of the Saharan Air Layer (SAL) and lightning during genesis of Tropical Depression (TD) 8 (2006) and TD 12 (2010) were investigated in relation to the interaction of the dust outbreaks with each system and their surrounding environment. This study applied data collected from the 2006 NASA African Monsoon Multidisciplinary Analysis and 2010 Genesis and Rapid Intensification Processes projects. Satellite observations from METEOSAT and Moderate Resolution Imaging Spectroradiometer (MODIS)Aerosol Optical Depth (AOD) were also employed for the study of the dust content. Lightning activity data from the Met Office Arrival Time Difference (ATD) system were used as another parameter to correlate moist convective overturning and a sign of cyclone formation. The AOD and lightning analysis for TD 8 demonstrated the time-lag connection through their positive contribution to TC-genesis. TD 12 developed without strong dust outbreak, but with lower wind shear (2 m s1) and an organized Mesoscale Convective System (MCS). Overall, the results from the combination of various data analyses in this study support the fact that both systems developed under either strong or weak dust conditions. From these two cases, the location (i.e., the target area) of strong versus weak dust outbreaks, in association with lightning, were essential interactions that impacted TC-genesis. While our dust footprints hypothesis applied under strong dust conditions (i.e., TD 8), other factors (e.g., vertical wind shear, pre-existing vortex and trough location, thermodynamics) need to be evaluated as well. The results from this study suggest that the SAL is not a determining factor that affects the formation of tropical cyclones (i.e., TD 8 and TD 12).", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/2015GL063040", "year": 2015, "title": "The fertilizing role of African dust in the Amazon rainforest: A first multiyear assessment based on data from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations", "abstract": "The productivity of the Amazon rainforest is constrained by the availability of nutrients, in particular phosphorus (P). Deposition of long-range transported African dust is recognized as a potentially important but poorly quantified source of phosphorus. This study provides a first multiyear satellite-based estimate of dust deposition into the Amazon Basin using three-dimensional (3-D) aerosol measurements over 20072013 from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). The 7 year average of dust deposition into the Amazon Basin is estimated to be 28 (848) Tg a1 or 29 (850) kg ha1 a1. The dust deposition shows significant interannual variation that is negatively correlated with the prior-year rainfall in the Sahel. The CALIOP-based multiyear mean estimate of dust deposition matches better with estimates from in situ measurements and model simulations than a previous satellite-based estimate does. The closer agreement benefits from a more realistic geographic definition of the Amazon Basin and inclusion of meridional dust transport calculation in addition to the 3-D nature of CALIOP aerosol measurements. The imported dust could provide about 0.022 (0.0060.037) Tg P of phosphorus per year, equivalent to 23 (739) g P ha1 a1 to fertilize the Amazon rainforest. This out-of-basin phosphorus input is comparable to the hydrological loss of phosphorus from the basin, suggesting an important role of African dust in preventing phosphorus depletion on timescales of decades to centuries.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1098/RSOS.140429", "year": 2015, "title": "The effects of precipitation, river discharge, land use and coastal circulation on water quality in coastal Maine", "abstract": "Faecal pollution in stormwater, wastewater and direct run-off can carry zoonotic pathogens to streams, rivers and the ocean, reduce water quality, and affect both recreational and commercial fishing areas of the coastal ocean. Typically, the closure of beaches and commercial fishing areas is governed by the testing for the presence of faecal bacteria, which requires an 1824 h period for sample incubation. As water quality can change during this testing period, the need for accurate and timely predictions of coastal water quality has become acute. In this study, we: (i) examine the relationship between water quality, precipitation and river discharge at several locations within the Gulf of Maine, and (ii) use multiple linear regression models based on readily obtainable hydrometeorological measurements to predict water quality events at five coastal locations. Analysis of a 12 year dataset revealed that high river discharge and/or precipitation events can lead to reduced water quality; however, the use of only these two parameters to predict water quality can result in a number of errors. Analysis of a higher frequency, 2 year study using multiple linear regression models revealed that precipitation, salinity, river discharge, winds, seasonality and coastal circulation correlate with variations in water quality. Although there has been extensive development of regression models for freshwater, this is one of the first attempts to create a mechanistic model to predict water quality in coastal marine waters. Model performance is similar to that of efforts in other regions, which have incorporated models into water resource managers' decisions, indicating that the use of a mechanistic model in coastal Maine is feasible.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.ECOLMODEL.2015.09.006", "year": 2015, "title": "The effects of long-term climate variability on the trophodynamics of an estuarine ecosystem in southern South America", "abstract": "The trophodynamics of the Rio de la Plata ecosystem over a long time scale (from 1948 to 2008) were simulated using a food-web model forced by two environmental factors. The Atlantic Meridional Mode (meridional sea surface temperature anomalies) was used as regional forcing, and the Rio de la Plata (RdlP) runoff was applied as local forcing. The entire food web was impacted by the regional forcing on a decadal scale; at the inter-annual scale, this remote factor had partial effects on the base of the food web. The RdlP runoff impacted primary producers and secondary consumers at the inter-annual scale. The higher effects of the local forcing were temporally coupled with seven of the strongest El Nino events from 1950 to 2008 (19571958, 19651966, 19721973, 19821983, 19861987, 19911992, 19971998). In contrast, the lower effects of RdlP runoff on the food web were coupled with six of the strongest La Nina events since 1950 (19501951, 19541956, 1964, 19701971, 19741975, 19881989). Total system biomass (trophic web attribute) and a measure of system entropy (holistic indicator) were used to identify ecosystem degradation. The entropy and total biomass of the RdlP ecosystem showed two opposite phases: before and after the early 1970s. During the period 19481971, the system showed high entropy and low total biomass, indicating high degradation. This cycle was reversed after 1972, and prevailed until the beginning of the 2000s. During this new cycle, the system entropy decreased and it was compensated by an increase in total system biomass. A sustainable entropy gain occurred after 2003, suggesting a new period of ecosystem degradation. The findings are discussed in light of temporal changes in the structural properties of this coastal ecosystem.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACPD-15-1523-2015", "year": 2015, "title": "The climatology of dust aerosol over the arabian peninsula", "abstract": "Abstract. Dust storms are considered to be a natural hazard over the Arabian Peninsula, since they occur all year round with maximum intensity and frequency in Spring and Summer. The Regional Climate Model version 4 (RegCM4) has been used to study the climatology of atmospheric dust over the Arabian Peninsula from 1999 to 2012. This relatively long simulation period samples the meteorological conditions that determine the climatology of mineral dust aerosols over the Arabian Peninsula. The modeled Aerosol Optical Depth (AOD) has been compared against ground-based observations of three Aerosol Robotic Network (AERONET) stations that are distributed over the Arabian Peninsula and daily space based observations from the Multi-angle Imaging SpectroRadiometer (MISR), the Moderate resolution Imaging SpectroRadimeter (MODIS) and Ozone Monitoring Instrument (OMI). The large scale atmospheric circulation and the land surface response that lead to dust uplifting have been analyzed. While the modeled AOD shows that the dust season extends from March to August with two pronounced maxima, one over the northern Arabian Peninsula in March with AOD equal to 0.4 and one over the southern Arabian Peninsula in July with AOD equal to 0.7, the observations show that the dust season extends from April to August with two pronounced maxima, one over the northern Arabian Peninsula in April with AOD equal to 0.5 and one over the southern Arabian Peninsula in July with AOD equal to 0.5. In spring a high pressure dominates the Arabian Peninsula and is responsible for advecting dust from southern and western part of the Arabian Peninsula to northern and eastern part of the Peninsula. Also, fast developed cyclones in northern Arabian Peninsula are responsible for producing strong dust storms over Iraq and Kuwait. However, in summer the main driver of the surface dust emission is the strong northerly wind (\"Shamal\") that transport dust from the northern Arabian Peninsula toward south parallel to the Arabian Gulf. The AERONET shortwave Top of Atmosphere Radiative Forcing (TOARF) and at the Bottom of Atmosphere Radiative Forcing (BOARF) have been analyzed and compared with the modeled direct radiative forcing of mineral dust aerosol. The annual modeled TOARF and BOARF are 3.3 and 12 W m2, respectively. However, the annual observed TOARF and BOARF are significantly different at 10 and 52 W m2, respectively. The analysis of observed and modeled TOARF agrees with previous studies in highlighting the need for more accurate specification of surface albedo over the region. Due to the high surface albedo of the central Arabian Peninsula, mineral dust aerosols tend to warm the atmosphere in summer (JuneAugust).", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-15-8809-2015", "year": 2015, "title": "The anthropogenic contribution to atmospheric black carbon concentrations in southern Africa: a WRF-Chem modeling study", "abstract": "Abstract. South Africa has one of the largest industrialized economies in Africa. Emissions of air pollutants are particularly high in the Johannesburg-Pretoria metropolitan area, the Mpumalanga Highveld and the Vaal Triangle, resulting in local air pollution. This study presents and evaluates a setup for conducting modeling experiments over southern Africa with the Weather Research and Forecasting model including chemistry and aerosols (WRF-Chem), and analyzes the contribution of anthropogenic emissions to the total black carbon (BC) concentrations from September to December 2010. The modeled BC concentrations are compared with measurements obtained at the Welgegund station situated ca. 100 km southwest of Johannesburg. An evaluation of WRF-Chem with observational data from ground-based measurement stations, radiosondes, and satellites shows that the meteorology is modeled mostly reasonably well, but precipitation amounts are widely overestimated and the onset of the wet season is modeled approximately 1 month too early in 2010. Modeled daily mean BC concentrations show a temporal correlation of 0.66 with measurements, but the total BC concentration is underestimated in the model by up to 50 %. Sensitivity studies with anthropogenic emissions of BC and co-emitted species turned off show that anthropogenic sources can contribute up to 100 % to BC concentrations in the industrialized and urban areas, and anthropogenic BC and co-emitted species together can contribute up to 60 % to PM1 levels. Particularly the co-emitted species contribute significantly to the aerosol optical depth (AOD). Furthermore, in areas of large-scale biomass-burning atmospheric heating rates are increased through absorption by BC up to an altitude of about 600hPa.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S00227-015-2689-6", "year": 2015, "title": "Temporal variation in intertidal community recruitment and its relationships to physical forcings, chlorophyll-a concentration and sea surface temperature", "abstract": "We investigated the recruitment of intertidal barnacles and mussels at three temporal scales (months, weeks and days), and its relationships to physical forcings, chlorophyll-a concentration (Chla) and sea surface temperature (SST), at both a local (km) and a regional (10100 km) resolution. The study was conducted in the South Brazilian Bight, a subtropical region influenced by upwelling and meteorological fronts, where recruitment rates were measured monthly, biweekly and daily, from 2012 to 2013 using artificial substrates fixed in the intertidal zone. The strength of the relationship between recruitment and physical forcings, Chla and SST depended on the temporal scale, with different trends observed for barnacles and mussels. Barnacle recruitment was positively correlated with wind speed and SST and negatively related to the wind direction, cold front events and Chla. Wind direction was positively correlated with mussel recruitment and negatively covaried with SST. We calculated net recruitment (NR) to estimate the differences in recruitment rates observed at longer time scales (months and weeks), with recruitment rates observed at shorter time scales (weeks and days), and found that NR varied in time and among taxa. These results suggest that wind-driven oceanographic processes might affect onshore abundance of barnacle larvae, causing the observed variation in recruitment. This study highlights the importance of oceanicclimatic variables as predictors of intertidal invertebrate recruitment and shows that climatic fluctuations might have different effects on rocky shore communities.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11356-014-3418-2", "year": 2015, "title": "Temporal variability of MODIS aerosol optical depth and chemical characterization of airborne particulates in Varanasi, India", "abstract": "Temporal variation of airborne particulate mass concentration was measured in terms of toxic organics, metals and water-soluble ionic components to identify compositional variation of particulates in Varanasi. Information-related fine particulate mass loading and its compositional variation in middle Indo-Gangetic plain were unique and pioneering as no such scientific literature was available. One-year ground monitoring data was further compared to Moderate Resolution Imaging Spectroradiometer (MODIS) Level 3 retrieved aerosol optical depth (AOD) to identify trends in seasonal variation. Observed AOD exhibits spatiotemporal heterogeneity during the entire monitoring period reflecting monsoonal low and summer and winter high. Ground-level particulate mass loading was measured, and annual mean concentration of PM2.5 (100.0 29.6 g/m3) and PM10 (176.1 85.0 g/m3) was found to exceed the annual permissible limit (PM10: 80 %; PM2.5: 84 %) and pose a risk of developing cardiovascular and respiratory diseases. Average PM2.5/PM10 ratio of 0.59 0.18 also indicates contribution of finer particulates to major variability of PM10. Particulate sample was further processed for trace metals, viz. Ca, Fe, Zn, Cu, Pb, Co, Mn, Ni, Cr, Na, K and Cd. Metals originated mostly from soil/earth crust, road dust and re-suspended dust, viz. Ca, Fe, Na and Mg were found to constitute major fractions of particulates (PM2.5: 4.6 %; PM10: 9.7 %). Water-soluble ionic constituents accounted for approximately 27 % (PM10: 26.9 %; PM2.5: 27.5 %) of the particulate mass loading, while sulphate (8.09.5 %) was found as most dominant species followed by ammonium (6.08.2 %) and nitrate (5.57.0 %). The concentration of toxic organics representing both aliphatic and aromatic organics was determined by organic solvent extraction process. Annual mean toxic organic concentration was found to be 27.5 12.3 g/m3 (n = 104) which constitutes significant proportion of (PM2.5, 1719 %; PM10, 1120 %) particulate mass loading with certain exceptions up to 50 %. Conclusively, compositional variation of both PM2.5 and PM10 was compared to understand association of specific sources with different fractions of particulates.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.MARENVRES.2015.10.006", "year": 2015, "title": "Temporal variability in epifaunal assemblages associated with temperate gorgonian gardens", "abstract": "The present study is one of the few that investigate the temporal variability of epifaunal assemblages associated with coral species, particularly the octocorals Eunicella gazella and Leptogorgia lusitanica in south Portugal. The results suggest time rather than colony size as a primary driver of the ecological patterns of these assemblages, which were dominated by amphipods, molluscs and polychaetes. Temporal variability was linked to changes in environmental parameters, namely temperature, chlorophyll a and particulate organic carbon. Hence, temporal variability must be taken into account for the design of future biodiversity assessment studies, as different patterns may be observed depending on the sampling time. Associated epifaunal assemblages were consistently dominated by resident species (i.e. species present in all sampling periods) and a peak of rare species was observed in the transition from spring to summer following the increase in seawater temperature. Turnover was particularly high in the transition between the spring and summer periods. In both hosts, turnover was higher in the small sized colonies, which harboured less diverse and less abundant assemblages that also differed from those inhabiting larger size colonies. The high levels of diversity associated with gorgonian colonies highlight the need for the conservation of this priority habitat.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/FOG.12104", "year": 2015, "title": "Temporal and spatial availability of Atlantic Thread Herring, Opisthonema oglinum, in relation to oceanographic drivers and fishery landings on the Florida Panhandle", "abstract": "Since 1995, landings of Atlantic Thread Herring (Opisthonema oglinum) on the Florida Panhandle averaged 124 mt each spring (AprilJune) but declined to nearly zero in 199697 and 2006. To elucidate causes of recurring periods of low landings, we used generalized additive mixed models (GAMMs) to examine the relationship between Atlantic Thread Herring catch in a trawl survey on the west-central coast of Florida and four environmental variables. Chlorophyll-a was significant in the models, indicating a direct relationship between local abundance of baitfish and their planktonic food. Temperature and depth were also significant whereas salinity was not. During 2003 and 2012, synoptic satellite-derived temperature and chlorophyll-a maps were used with the GAMMs to predict monthly spatial availability on the Florida Panhandle fishing grounds (long. 8588o W and depth 1225 m). The predicted monthly availability was significantly correlated with commercial catch rates (Pearson's r = 0.26, P = 0.004, d.f. = 118). We used multiple linear regression (MLR) with lags to describe the effect of river discharge and wind (as a transport mechanism) on surface chlorophyll-a over the Panhandle fishing grounds. Discharge from local rivers was significant in all MLRs, and the Mississippi was only significant as an interaction with wind. We conclude that Atlantic Thread Herring are distributed over the Panhandle fishing grounds based on food availability that is driven by river discharge and eastward transport of Mississippi River plumes. This analysis improves our understating of baitfish dynamics, an important ecosystem component in the Gulf of Mexico.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1098/RSPB.2014.2260", "year": 2015, "title": "Symbiodinium identity alters the temperature-dependent settlement behaviour of Acropora millepora coral larvae before the onset of symbiosis", "abstract": "The global distribution of marine species, many of which disperse during the larval stages, is influenced by ocean temperature regimes. Here, we test how temperature and the coral symbionts (Symbiodinium) affect survival, symbiont uptake, settlement success and habitat choice of Acropora millepora larvae. Experiments were conducted at Heron Island (Australia), where larvae were exposed to 22.5, 24.5, 26.5 and 28.5C. Within each temperature treatment, larvae were offered symbionts with distinct characteristics: (i) homologous Symbiodinium type C3, (ii) regionally homologous thermo-tolerant type D1, and (iii) heterologous thermo-tolerant type C15, as well as controls of (iv) un-filtered and (v) filtered seawater. Results show that lower instead of higher temperatures adversely affected recruitment by reducing larval survival and settlement. Low temperatures also reduced recruit habitat choice and initial symbiont densities, both of which impact on post-settlement survival. At lower temperatures, larvae increasingly settle away from preferred vertical surfaces and not on crustose coralline algae (CCA). Surprisingly, substrate preference to CCA was modified by the presence of specific symbiont genotypes that were present ex-hospite (outside the coral larvae). When different symbionts were mixed, the outcomes were non-additive, indicating that symbiont interactions modify the response. We propose that the observed influence of ex-hospite symbionts on settlement behaviour may have evolved through ecological facilitation and the study highlights the importance of biological processes during coral settlement.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1086/682363", "year": 2015, "title": "Switch between Morphospecies of Pocillopora Corals", "abstract": "Pocillopora corals are the main reef builders in the eastern tropical Pacific. The validity of Pocillopora morphospecies remains under debate because of disagreements between morphological and genetic data. To evaluate the temporal stability of morphospecies in situ, we monitored the shapes of individual colonies in three communities in the southern Gulf of California for 44 months. Twenty-three percent of tagged colonies of Pocillopora damicornis changed to Pocillopora inflata morphology during this time. This switch in identity coincided with a shift to a higher frequency of storms and lower water turbidity (i.e., lower chlorophyll a levels). Seven months after the switch, P. inflata colonies were recovering their original P. damicornis morphology. All colonies of both morphospecies shared a common mitochondrial identity, but most P. damicornis colonies undergoing change were at a site with low-flow conditions. This is the first in situ study to document switching between described morphospecies, and it elucidates the influence of temporal shifts in environmental conditions on morphologically plastic responses.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1155/2015/247531", "year": 2015, "title": "Study of Aerosols Characteristics and Dynamics over the Kingdom of Saudi Arabia Using a Multisensor Approach Combined with Ground Observations", "abstract": "This study covers various aspects of the aerosol distribution and characteristics, namely, optical depth climatology, absorption characteristics, and their microphysical properties over four regions in Saudi Arabia using satellite and ground observations including MODIS/Terra and Aqua, OMI, MISR/Terra, AERONET, and CALIPSO for the period April 2003January 2013. The study includes cities in the North Western, Western, Eastern provinces of Saudi Arabia and in the Rub al Khali desert or Empty Quarter. Satellite and ground observations showed that the dust season extends from April to August with prominent peaks yet with high anthropogenic contribution late summer and early fall. Analysis shows an increase in the aerosol concentration during March 2009 which could be attributed to a major dust storm during that time. Comparing the AOD time series over regions 13 and region 4 (desert) we observe monthly and annual variability with no recurrence pattern over the years. The Aqua Deep Blue AOD550 data shows a single peak pattern that occurs over region 4 during the spring season known for its frequent dust events. OMI data shed the light on the presence of higher air pollution levels over region 3, representing the oil rich eastern province of Saudi Arabia.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2015.06.015", "year": 2015, "title": "Spatiotemporal characteristics of aerosols in India: Observations and model simulations", "abstract": "An analysis of aerosol characteristics measured using sun photometers, MODIS and MISR, and simulated using global aerosol models (GOCART and MOZART) over six distinctly different environments in India reveal significant regional and temporal variations. Model AODs are lower than measured AODs, and exhibit a winter low and summer high, while features in measured AODs differ. MODIS and MISR AODs are higher than model simulated AODs. Differences between measured and model AODs arise due to absence of seasonal cycle in model AODs which occurs mainly due to lack of proper representation of aerosol emissions and not due to meteolorogy. In model simulations dust (>40% during premonsoon) and sulfate (40% during monsoon) contribute the maximum to total AOD. Model derived single scattering albedo (SSA) is higher than measured SSA over the study locations because simulated BC is low. The inter-annual variability in model derived SSA is lower than model-observation differences in SSA. The intra-regional variation in model AODs is lower than that of MODIS AODs. Sea salt contributes 10% to total AOD during monsoon only over Peninsular and west Central India. The underestimation of AODs by GOCART and MOZART and space-time differences with observations strongly favors improving the emission inventories of aerosol sources and removal mechanisms of aerosols in the models. Results from present study can serve as inputs to tune models because not only total AODs but also species AODs, and their amount need to be properly simulated in order to reduce the uncertainty in radiative and climate impact of aerosols.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.4209/AAQR.2014.09.0200", "year": 2015, "title": "Spatio-Temporal Distribution of Aerosol and Cloud Properties over Sindh Using MODIS Satellite Data and a HYSPLIT Model", "abstract": "ABSTRACTIn this study, aerosols spatial, seasonal and temporal variations over Sindh, Pakistan were analyzed which can lead to variations in the microphysics of clouds as well. All cloud optical properties were analyzed using Moderate Resolution Imaging Spectroradiometer (MODIS) data for 12 years from 2001 to 2013. We also monitored origin and movements of air masses that bring aerosol particles and may be considered as the natural source of aerosol particles in the region. For this purpose, the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to make trajectories of these air masses from their sources. Aerosol optical depth (AOD) high values were observed in summer during the monsoon period (JuneAugust). The highest AOD values in July were recorded ranges from 0.41 to 1.46. In addition, low AOD values were found in winter season (DecemberFebruary) particularly in December, ranges from 0.16 to 0.69. We then analyzed the relationship between AOD and Angstrom exponent that is a good indicator of the size of an aerosol particle. We further described the relationships of AOD and four cloud parameters, namely water vapor (WV), cloud fraction (CF), cloud top temperature (CTT) and cloud top pressure (CTP) by producing regional correlation maps of their data values. The analyses showed negative correlation between AOD and Angstrom exponent especially in central and western Sindh. The correlation between AOD and WV was throughout positive with high correlation values > 0.74 in whole Sindh except eastern most arid strip of the Thar Desert in the region. The correlation between AOD and CF was positive in southern Sindh and goes to negative in northern Sindh. AOD showed a positive correlation with CTP and CTT in northern Sindh and a negative correlation in southern Sindh. All these correlations were observed to be dependent on the meteorological conditions for all of the ten sites investigated.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.DSR.2015.04.007", "year": 2015, "title": "Spatio-temporal distribution and transport of particulate matter in the eastern tropical North Atlantic observed by Argo floats", "abstract": "The spatial and temporal distribution of particulate matter in the water column of the eastern tropical North Atlantic between 16.922.9N and 16.629.3W was investigated using optical measurements from transmissometers mounted on Argo floats. The corresponding profiles of beam attenuation coefficients measured from February 2008 to May 2009 were used to study particulate matter in different layers such as the surface nepheloid layer (SNL), subsurface nepheloid layer (SSNL), intermediate nepheloid layer (INL) and bottom nepheloid layer (BNL) as well as to investigate sinking particles (SP). The SNL were down to about 60m water depth at thicknesses between 20 and 60m. Our analyses verified high correlation between particulate matter and phytoplankton in the SNL. High offshore SNL extension of up to 750km was found in the area of Cape Blanc filaments in January 2009. Their typical widths ranged from 11 to 72km. Furthermore, float-borne observations even resolved atmospheric dust deposition into the surface water layer during a strong Saharan dust event in October 2008. The observed dust concentration in the mixed water layer was found to vary between 0.0021 and 0.0168gm3 depending on applied assumptions. An abrupt change from a SNL to a SSNL regime over distances of only 80 to 90km was observed. The particulate matter in the SSNL showed lateral extensions from 420 to 1020km offshore. A statistically significant correlation between the depth of subsurface particle maxima and the distance to shore was found. An averaged diameter of 30km was determined for the sharply isolated patches of INL which was consistent with model simulations of other studies. The lateral transport of particulate matter in these INL features in the area of the giant Cape Blanc filaments was found to be more pronounced than reported in earlier studies. The distribution of particulate matter within the INL filaments reached up to 610km off the shelf edge. The frequency of INL decreased with increasing distance to shore. The sinking velocity of particulate matter of one long-term observed INL was approximately 1.3mday1. Highly concentrated BNLs with beam attenuation coefficients of up to 4.530m1 were observed in the continental slope region. INLs appeared more frequently than SP events which lead to the conclusion that the lateral transport of particulate matter in INL features in the study area was more important than their passive vertical sinking.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/978-3-319-09057-3_286", "year": 2015, "title": "Spatial Pattern of Hydrological Predictability of Landslide-Prone Areas", "abstract": "In this paper, the authors argue that integration of the hydrological model for landslide-prone areas should proceed under a soft geovisual communication in order to mitigate the uncertainty involved in downscaling rainstorm hazard mapping and geocomputational tracking. In this respect, examples of geovisualized spatial patterns for Terminio-Tuoro area affected by damaging landslide events is given by the rainstorm hazard index (RHI)kriged probability map. These findings should contribute to improving the information base needed to implement and monitor a sound strategy for warning, forecasting and planning landslide hazard.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JASTP.2015.05.015", "year": 2015, "title": "Solar global horizontal and direct normal irradiation maps in Spain derived from geostationary satellites", "abstract": "Solar radiation derived from satellite imagery is a powerful and highly accurate technique for solar resource assessment due to its maturity and to the long term database of observation images available. This work presents the methodology developed at CIEMAT for mapping solar radiation from geostationary satellite information and it also shows solar irradiation maps of global horizontal and direct normal components elaborated for Spain. The maps presented here have been developed from daily solar irradiation estimated for eleven years of satellite images (20012011). An attempt to evaluate the uncertainty of the presented maps is made using ground measurements from 27 meteorological stations available in Spain for global horizontal irradiation obtained from the World Radiation Data Centre. In the case of direct normal irradiation the ground measurement database was scarce, having available only six ground stations with measurements for a period of 4 years. Yearly values of global horizontal irradiation are around 1800kWhm2 in most of the country and around 19502000kWhm2 for annual direct normal irradiation. Root mean square errors in monthly means were of 11% and of 29% for global horizontal and direct normal irradiation, respectively.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S10346-015-0618-X", "year": 2015, "title": "Soil moisture and precipitation thresholds for real-time landslide prediction in El Salvador", "abstract": "Described is the development of a regional forecasting system for landslide hazard threat level, suitable for use operationally by forecasting and disaster management agencies. The system utilizes spatially distributed operational hydrologic models to estimate depth-integrated soil moisture on basin scales of order 160 km2, with forcing of remotely sensed and on-site precipitation data. The depth-integrated soil moisture data and the precipitation forcing are used together with regional databases of landslide occurrence to develop threshold curves in the precipitation/soil moisture space that allow the prediction of landslide hazard threat level on satellite-derived rainfall pixel scales. Predetermined susceptibility maps may then be used together with the real-time prediction of hazard threat level for a particular rainfall pixel to determine the slopes within the pixel that are more likely to fail in real time and to characterize a given pixel as susceptible or non-susceptible to landsliding for real-time prediction. The operational system development requires global satellite precipitation estimates with short latency, real-time precipitation data from sparse rain gauges in the region, and a regional database of historical landslide events with location and timing information. Parametric databases that support the operational hydrologic model consist of soil texture by depth and land-use/land-cover information. The case study presented is for the country of El Salvador. The study shows the feasibility of the regional system development and the validation of the assumed existence of a threshold curve in two-dimensional space consisting of the depth-integrated soil moisture and of the forcing precipitation. The resulting threshold curve, when examined with data from the period 20062011 in El Salvador, resulted in warnings of landslide occurrence with frequency that spanned the range between 1 and 5 % of the days for the basins identified to be susceptible to landsliding.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1371/JOURNAL.PONE.0129437", "year": 2015, "title": "Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle", "abstract": "In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi) were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas) allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/2015JD023547", "year": 2015, "title": "Separating aerosol microphysical effects and satellite measurement artifacts of the relationships between warm rain onset height and aerosol optical depth", "abstract": "AbstractThe high resolution (375 m) of the Visible Infrared Imaging Radiometer Suite on board the Suomi National Polar-Orbiting Partnership satellite allows retrieving relatively accurately the vertical evolution of convective cloud drop effective radius (re) with height or temperature. A tight relationship is found over SE Asia and the adjacent seas during summer between the cloud-free aerosol optical depth (AOD) and the cloud thickness required for the initiation of warm rain, as represented by the satellite-retrieved cloud droplet re of 14 m, for a subset of conditions that minimize measurement artifacts. This cloud depth (T14) is parameterized as the difference between the cloud base temperature and the temperature at the height where re exceeds 14 m (T14). For a unit increase of AOD, the height of rain initiation is increased by about 5.5 km. The concern of data artifacts due to the increase in AOD near clouds was mitigated by selecting only scenes with cloud fraction (CF) < 0.1. For CF > 0.1 and T14 > 20C, the increase of T14 gradually levels off with further increase of AOD, possibly because the AOD is enhanced by aerosol upward transport and detrainment through the clouds below the T14 isotherm. The bias in the retrieved re due to the different geometries of solar illumination was also quantified. It was shown that the retrievals are valid only for backscatter views or when avoiding scenes with significant amount of cloud self-shadowing. These artifacts might have contributed to past reported relationships between cloud properties and AOD.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/MEC.13471", "year": 2015, "title": "Seascape genetics along environmental gradients in the Arabian Peninsula: insights from ddRAD sequencing of anemonefishes", "abstract": "Understanding the processes that shape patterns of genetic structure across space is a central aim of landscape genetics. However, it remains unclear how geographical features and environmental variables shape gene flow, particularly for marine species in large complex seascapes. Here, we evaluated the genomic composition of the two-band anemonefish Amphiprion bicinctus across its entire geographical range in the Red Sea and Gulf of Aden, as well as its close relative, Amphiprion omanensis endemic to the southern coast of Oman. Both the Red Sea and the Arabian Sea are complex and environmentally heterogeneous marine systems that provide an ideal scenario to address these questions. Our findings confirm the presence of two genetic clusters previously reported for A. bicinctus in the Red Sea. Genetic structure analyses suggest a complex seascape configuration, with evidence of both isolation by distance (IBD) and isolation by environment (IBE). In addition to IBD and IBE, genetic structure among sites was best explained when two barriers to gene flow were also accounted for. One of these coincides with a strong oligotrophic-eutrophic gradient at around 16-20 N in the Red Sea. The other agrees with a historical bathymetric barrier at the straight of Bab al Mandab. Finally, these data support the presence of interspecific hybrids at an intermediate suture zone at Socotra and indicate complex patterns of genomic admixture in the Gulf of Aden with evidence of introgression between species. Our findings highlight the power of recent genomic approaches to resolve subtle patterns of gene flow in marine seascapes.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/SREP08273", "year": 2015, "title": "Water column productivity and temperature predict coral reef regeneration across the Indo-Pacific", "abstract": "Predicted increases in seawater temperatures accelerate coral reef decline due to mortality by heat-driven coral bleaching. Alteration of the natural nutrient environment of reef corals reduces tolerance of corals to heat and light stress and thus will exacerbate impacts of global warming on reefs. Still, many reefs demonstrate remarkable regeneration from past stress events. This paper investigates the effects of sea surface temperature (SST) and water column productivity on recovery of coral reefs. In 71 Indo-Pacific sites, coral cover changes over the past 1-3 decades correlated negative-exponentially with mean SST, chlorophyll a and SST rise. At six monitoring sites (Persian/Arabian Gulf, Red Sea, northern and southern Galapagos, Easter Island, Panama), over half of all corals were <31 years, implying that measured environmental variables indeed shaped populations and community. An Indo-Pacific-wide model suggests reefs in the northwest and central Indian Ocean, as well as the central west Pacific, are at highest risk of degradation and those at high latitudes the least. The model pinpoints regions where coral reefs presently have the best chances for survival. However, reefs best buffered against temperature and nutrient effects are those that current studies suggest to be most at peril from future ocean acidification.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1371/JOURNAL.PMED.1001893", "year": 2015, "title": "Water Supply Interruptions and Suspected Cholera Incidence: A Time-Series Regression in the Democratic Republic of the Congo", "abstract": "Background The eastern provinces of the Democratic Republic of the Congo have been identified as endemic areas for cholera transmission, and despite continuous control efforts, they continue to experience regular cholera outbreaks that occasionally spread to the rest of the country. In a region where access to improved water sources is particularly poor, the question of which improvements in water access should be prioritized to address cholera transmission remains unresolved. This study aimed at investigating the temporal association between water supply interruptions and Cholera Treatment Centre (CTC) admissions in a medium-sized town. Methods and Findings Time-series patterns of daily incidence of suspected cholera cases admitted to the Cholera Treatment Centre in Uvira in South Kivu Province between 2009 and 2014 were examined in relation to the daily variations in volume of water supplied by the town water treatment plant. Quasi-poisson regression and distributed lag nonlinear models up to 12 d were used, adjusting for daily precipitation rates, day of the week, and seasonal variations. A total of 5,745 patients over 5 y of age with acute watery diarrhoea symptoms were admitted to the CTC over the study period of 1,946 d. Following a day without tap water supply, the suspected cholera incidence rate increased on average by 155% over the next 12 d, corresponding to a rate ratio of 2.55 (95% CI: 1.544.24), compared to the incidence experienced after a day with optimal production (defined as the 95th percentile4,794 m3). Suspected cholera cases attributable to a suboptimal tap water supply reached 23.2% of total admissions (95% CI 11.4%33.2%). Although generally reporting less admissions to the CTC, neighbourhoods with a higher consumption of tap water were more affected by water supply interruptions, with a rate ratio of 3.71 (95% CI: 1.917.20) and an attributable fraction of cases of 31.4% (95% CI: 17.3%42.5%). The analysis did not suggest any association between levels of residual chlorine in the water fed to the distribution network and suspected cholera incidence. Laboratory confirmation of cholera was not available for this analysis. Conclusions A clear association is observed between reduced availability of tap water and increased incidence of suspected cholera in the entire town of Uvira in Eastern Democratic Republic of the Congo. Even though access to piped water supplies is low in Uvira, improving the reliability of tap water supply may substantially reduce the incidence of suspected cholera, in particular in neighbourhoods having a higher access to tap water. These results argue in favour of water supply investments that focus on the delivery of a reliable and sustainable water supply, and not only on point-of-use water quality improvements, as is often seen during cholera outbreaks.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1002/2014JC010218", "year": 2015, "title": "Winter bloom and associated upwelling northwest of the Luzon Island: A coupled physical-biological modeling approach", "abstract": "For this paper, a coupled physical-biological model was developed in order to study the mechanisms of the winter bloom in the Luzon Strait (referred as LZB). Based on a simulation for January 2010, the results showed that the model was capable of reproducing the key features of the LZB, such as the location, inverted-V shape, twin-core structure and bloom intensity. The simulation showed that the LZB occurred during the relaxation period of intensified northeasterly winds, when the deepened mixed layer started to shoal. Nutrient diagnostics showed that vertical mixing was responsible for the nutrient supply to the upper 40 m layer, while subsurface upwelling supplied nutrients to the region below the mixed layer. Hydrodynamic diagnostics showed that the advection of relative vorticity (RV) primarily contributed to the subsurface upwelling. The RV advection was resulted from an offshore jet, which was associated with a northeasterly wind, flowed across the ambient RV field.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1134/S0001433815020024", "year": 2015, "title": "Winterspring anomalies in the stratospheric content of NO2 from ground-based measurement results", "abstract": "According to the results of ground-based spectrometric measurements, significant negative anomalies in the stratospheric content of NO2 were observed at a number of stations in the Northern Hemisphere during winter and spring 2011. These anomalies were accompanied by those in total ozone content (TOC) and stratospheric temperature and were caused by the transport of air masses from the region of the arctic ozone hole. The results of analysis of vertical NO2 profiles obtained at the Zvenigorod Scientific Station showed that a certain contribution to the 2011 negative anomalies of NO2 was made due to a denitrification of the polar stratosphere in the ozone-hole region. The relation between variations in the total content of NO2 and those in the TOC and temperature was analyzed for both the Northern and Southern hemispheres during winterspring periods. It was found that this relation depends on the phase of the quasi-biennial oscillation in the stratospheric equatorial wind. Such a correlation usually intensifies if only the episodes of negative anomalies caused by the transport of stratospheric air masses from the ozone-hole region are taken into consideration.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.18052/WWW.SCIPRESS.COM/ILCPA.50.188", "year": 2015, "title": "Satellite Derived Aerosol Optical Depth Climatology over Tropical Coastal Station Machilipatnam, India", "abstract": "Climatological aerosol optical depths (AOD) over Tropical coastal city Machilipatnam, India have been examined to bring out the temporal heterogeneity in columnar aerosol characteristics. AOD values at 388 nm derived from the Ozone Monitoring Instrument (OMI) sensor EOS-AURA satellite, for the period of 20052013 have been analyzed for the purpose. AOD trends exhibited seasonal annual mean variations. Frequency distributions of the AOD values are examined to infer the monthly mean values. Monthly and seasonal variations of AOD are investigated in the light of regional synoptic meteorology. AODs>0.6 showed maximum occurrence in monsoon months. The mean AOD values increased towards summer reaching 0.69 0.34 and attained peak in monsoon season with a value of 0.74 0.33 and decreased during post-monsoon reaching as low as 0.73 0.3. Positive slope 0.016 observed for inter annual distribution trend line. Factors like synoptic scale circulation patterns which are causing modulations of AOD apart from local sources were discussed.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/978-3-319-24474-7_9", "year": 2015, "title": "Satellite Data Science: A Case Study for Smog Disaster Prediction from Multiple Satellite Observations", "abstract": "Smog Disaster studies of PM2.5PM2.5\\text {PM}_{2.5} are limited by the lack of monitoring data, especially in developing countries. Satellite observations offer valuable global information about PM2.5PM2.5\\text {PM}_{2.5} concentrations, but have limited accuracy and completeness. In contrast to satellite domain-driven methods for PM2.5PM2.5\\text {PM}_{2.5} retrieval, our approach is satellite data-driven. Challenges and our proposed solutions discussed here in context of global scale PM2.5PM2.5\\text {PM}_{2.5} estimation include (i) PM2.5PM2.5\\text {PM}_{2.5} regression from Aerosol Optical Depth (AOD) data; (ii) training such a multi-view model for robust performance across multiple satellite measures; and (iii) the model for incomplete data avoids direct imputation of the missing elements. Experimental results on real-world data sets show that it significantly outperforms the existing approaches.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1080/01431161.2015.1060646", "year": 2015, "title": "Saharan dust as a causal factor of hemispheric asymmetry in aerosols and cloud cover over the tropical Atlantic Ocean", "abstract": "Previous studies showed that, over the global ocean, there is no noticeable hemispheric asymmetry in cloud fraction (CF). This contributes to the balance in solar radiation reaching the sea surface in the northern and southern hemispheres. In the current study, we focus on the tropical Atlantic (30 N30 S), which is characterized by significant amounts of Saharan dust dominating other aerosol species over the North Atlantic. Our main point is that, over the tropical Atlantic, Saharan dust not only is responsible for the pronounced hemispheric aerosol asymmetry, but also contributes to significant cloud cover along the Saharan Air Layer (SAL). Over the tropical Atlantic in July, along the SAL, Moderate Resolution Imaging Spectroradiometer CF data showed significant cloud cover (up to 0.80.9). This significant CF along SAL together with clouds over the Atlantic Intertropical Convergence Zone contributes to the 20% hemispheric CF asymmetry. This leads to the imbalance in strong solar radiation, which reaches the sea surface between the tropical North and South Atlantic, and, consequently, affects climate formation in the tropical Atlantic. During the 10-year study period (July 2002June 2012), NASA Aerosol Reanalysis (aka MERRAero) showed that, when the hemispheric asymmetry in dust aerosol optical thickness (AOT) was most pronounced (particularly in July), dust AOT averaged separately over the tropical North Atlantic was one order of magnitude higher than that averaged over the tropical South Atlantic. In the presence of such strong hemispheric asymmetry in dust AOT in July, CF averaged separately over the tropical North Atlantic exceeded that over the tropical South Atlantic by 20%. Both Multiangle Imaging Spectroradiometer measurements and MERRAero data were in agreement on seasonal variations in hemispheric aerosol asymmetry. Hemispheric asymmetry in total AOT over the Atlantic was most pronounced between March and July, when dust presence over the North Atlantic was maximal. In September and October, there was no noticeable hemispheric aerosol asymmetry between the tropical North and South Atlantic. During the season with no noticeable hemispheric aerosol asymmetry, we found no noticeable asymmetry in cloud cover.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1515/EKO-2015-0006", "year": 2015, "title": "Remote Sensing of Suspended Sediment Over Gulf of Martaban", "abstract": "AbstractGulf of Martaban is located at the north of Andaman, and is one of the world most turbid areas. The presence of suspended sediment concentration (SSC) in the water body could reduce the underwater transmittance. This study has been conducted to investigate the variation of SSC over the Gulf of Martaban. Remote sensing reflectance (Rrs) of 667 nm is used as a proxy to represent the sediment SSC variation over the study area. The data for the period of July 2002 to March 2014 acquired from MODIS Aqua 4 km resolution are used in this study. As a result, there is no obvious yearly variation in the SSC cover area. The SSC variation over this study area is found to be seasonal. High homogenous SSC covers area observably during the northeast (NE) monsoon season that occurs from December to January. The sediment cover area could reach the latitude of 15N that located at the south of the gulf. During southwest (SW) monsoon season that occurs from May to September, low and sparse SSC cover area is observed. As a consequence, the area covered by the SSC is higher during the NE monsoon season as compared to the SW monsoon season. Hence, the SSC cover area during the NE monsoon season is greater than the yearly averaged SSC cover area. Meanwhile the SSC cover area during the rainy SW monsoon season is less than the yearly and NE monsoon season.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.5194/BG-12-2411-2015", "year": 2015, "title": "Reconciling single-chamber Mg / Ca with whole-shell 18O in surface to deep-dwelling planktonic foraminifera from the Mozambique Channel", "abstract": "Abstract. Most planktonic foraminifera migrate vertically through the water column during life, meeting a range of depth-related conditions as they grow and calcify. For reconstructing past ocean conditions from geochemical signals recorded in their shells, it is therefore necessary to know vertical habitat preferences. Species with a shallow habitat and limited vertical migration will reflect conditions of the surface mixed layer and short-term and mesoscale (i.e. seasonal) perturbations therein. Species spanning a wider range of depth habitats, however, will contain a more heterogeneous, intra-specimen variability (e.g. Mg / Ca and 18O), which is less for species calcifying below the thermocline. Obtained single-chamber Mg / Ca ratios are combined with single-specimen 18O and 13C of the surface-water inhabitant Globigerinoides ruber, the thermocline-dwelling Neogloboquadrina dutertrei and Pulleniatina obliquiloculata, and the deep dweller Globorotalia scitula from the Mozambique Channel. Species-specific Mg / Ca, 13C and 18O data combined with a depth-resolved mass balance model confirm distinctive migration and calcification patterns for each species as a function of hydrography. Whereas single-specimen 18O rarely reflects changes in depth habitat related to hydrography (e.g. temperature), measured Mg / Ca of the last chambers can only be explained by active migration in response to changes in temperature stratification. Foraminiferal geochemistry and modelled depth habitats shows that the single-chamber Mg / Ca and single shell 18O are in agreement with each other and in line with the changes in hydrography induced by eddies.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.17159/SAJS.2015/20140133", "year": 2015, "title": "Real-time measurement of outdoor workers exposure to solar ultraviolet radiation in Pretoria, South Africa", "abstract": "The city of Pretoria in South Africa receives considerable solar ultraviolet radiation (UVR) because of its low latitude (2235S) and relatively clear skies. Certain meteorological factors affect the amount of solar UVR that reaches the ground; the most dominant factors being stratospheric ozone, cloud cover and solar zenith angle. It is known that overexposure to solar UVR may lead to the development of adverse health conditions, the most significant being skin cancer. Outdoor workers spend a significant amount of time outside and are thus susceptible to this risk. In this case study, we estimated, for the first time, the realtime solar UVR exposure of an outdoor worker in Pretoria. Measurements were made on 27 and 28 May 2013 using a handheld ultraviolet index (UVI) meter calibrated against a science-grade biometer at the South African Weather Service in Pretoria. Personal exposure estimation was used to discern the pattern in diurnal and annual sunburn risk for the outdoor worker. Ambient UVR levels ranged from 0 UVI to 4.66 UVI and the outdoor workers potential exposure estimates regularly exceeded 80% of these levels depending on the time of day. The risk of sunburn was evident; however, actual incidents would depend on individual skin photosensitivity and melanin content, as well as sun protection used. Further research is needed to determine the personal exposure estimations of outdoor workers in other provinces in which solar UVR levels may be equally high, or higher than those in Pretoria.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.SCITOTENV.2015.02.023", "year": 2015, "title": "Prevalence of microbiological contaminants in groundwater sources and risk factor assessment in Juba, South Sudan", "abstract": "In low-income regions, drinking water is often derived from groundwater sources, which might spread diarrheal disease if they are microbiologically polluted. This study aimed to investigate the occurrence of fecal contamination in 147 improved groundwater sources in Juba, South Sudan and to assess potential contributing risk factors, based on bivariate statistical analysis. Thermotolerant coliforms (TTCs) were detected in 66% of the investigated sources, including 95 boreholes, breaching the health-based recommendations for drinking water. A significant association (p<0.05) was determined between the presence of TTCs and the depth of cumulative, long-term prior precipitation (both within the previous five days and within the past month). No such link was found to short-term rainfall, the presence of latrines or damages in the borehole apron. However, the risk factor analysis further suggested, to a lesser degree, that the local topography and on-site hygiene were additionally significant. In summary, the analysis indicated that an important contamination mechanism was fecal pollution of the contributing groundwater, which was unlikely due to the presence of latrines; instead, infiltration from contaminated surface water was more probable. The reduction in fecal sources in the environment in Juba is thus recommended, for example, through constructing latrines or designating protection areas near water sources. The study results contribute to the understanding of microbiological contamination of groundwater sources in areas with low incomes and high population densities, tropical climates and weathered basement complex environments, which are common in urban sub-Saharan Africa.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1111/IVB.12104", "year": 2015, "title": "Population-dependent acclimatization capacity of thermal tolerance in larvae of the rocky-shore barnacle Pollicipes elegans", "abstract": "As environmental temperatures increase and become more seasonally variable, the ability of individuals to plastically alter their physiological responses to temperature (=acclimatize) may affect the potential for species persistence. Among marine organisms, the larval stage is often the most physiologically sensitive; larvae are also often the main dispersal stage in the life history. However, studies that address the acclimatization of marine larvae are rare. We investigated whether larvae of the gooseneck barnacle Pollicipes elegans from two temperate populations, one from the Northern Hemisphere (Mexico) and one from the Southern Hemisphere (Peru), show patterns of seasonal acclimatization to temperature. We compared the effects of temperature on swimming activity, oxygen consumption, and mortality of larvae from the two populations in both warm and cold seasons. Larvae from Mexico had higher thermal tolerances when collected in the boreal summer compared to the boreal winter, while no similar indication of seasonal acclimatization was seen in larvae from Peru. The lack of acclimatization in larvae of P. elegans from Peru may be related to recent thermal history, low selection for acclimatization due to irregular patterns of seasonal temperature change during ENSO events, or to different phylogeographic histories of Northern- and Southern-hemisphere populations.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11356-015-4928-2", "year": 2015, "title": "PM10 and PM2.5 composition over the Central Black Sea: origin and seasonal variability", "abstract": "Daily PM10 and PM2.5 samples were collected between April 2009 and July 2010 at a rural site (Sinop) situated on the coast of the Central Black Sea. The concentrations of PM10 and PM2.5 were 23.2 16.7 and 9.8 6.9 g m3, respectively. Coarse and fine filters were analyzed for Cl, NO3, SO42, C2O42, PO43, Na+, NH4+, K+, Mg2+, and Ca2+ by using ion chromatography. Elemental and organic carbon content in bulk quartz filters were also analyzed. The highest PM2.5 contribution to PM10 was found in summer with a value of 0.54 due to enhanced secondary aerosols in relation to photochemistry. Cl, Na+, and Mg2+ illustrated their higher concentrations and variability during winter. Chlorine depletion was chiefly attributed to nitrate. Higher nssCa2+ concentrations were ascribed to episodic mineral dust intrusions from North Africa into the region. Crustal material (31 %) and sea salt (13 %) were found to be accounted for the majority of the PM10. The ionic mass (IM), particulate organic matter (POM), and elemental carbon (EC) explained 13, 20, and 3 % of the PM10 mass, correspondingly. The IM, POM, and EC dominated the PM2.5 (~74 %) mass. Regarding EU legislation, the exceeded PM2.5 values were found to be associated with secondary aerosols, with a particular dominance of POM. For the exceeded PM10 values, six of the events were dominated by dust while two and four of these exceedances were caused by sea salt and mix events, respectively.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/978-94-017-9661-3_3", "year": 2015, "title": "Physical and Anthropogenic Factors", "abstract": "Natural hazards are controlled by many physical and anthropogenic factors that govern the level of risk and its geographic distribution. These factors vary between regions and are not well defined; different studies have produced contradictory findings. The present study investigated the fundamental factors that influence floods and torrents in Jeddah city and the surrounding area, based on the flood events that took place in 2009 and 2011.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.AGRFORMET.2014.12.008", "year": 2015, "title": "Patterns of energy exchange for tropical ecosystems across a climate gradient in Mato Grosso, Brazil", "abstract": "The spatial and temporal variations in the partitioning of energy into latent (LE) and sensible (H) heat flux for tropical ecosystems are not yet fully understood. In the state of Mato Grosso State, Brazil, there are three different ecosystems (Cerrado, Pantanal and the Amazon Rainforest) with distributions that vary across rainfall and humidity gradients. Our goal was to analyze the seasonal variation in microclimate, spectral reflectance, LE and H for these ecosystems and quantify how energy partitioning varies across the regional climate gradient. We used the Bowen ratio energy balance method to estimate the LE and H of a dense, evergreen ombrophylous forest near Alta Floresta (AFL), a semi-deciduous forest in the Amazon-Cerrado transition zone near Sinop (SIN), a savanna grassland at Fazenda Miranda (FMI), a managed savanna pasture at Fazenda Experimental (FEX), a seasonally flooded woodland at Baia das Pedras in the Pantanal (BPE), and a riparian forest dominated by Vochysia divergens Pohl (CAM) in the Pantanal. Annual rainfall decreased from north to south, and 83% of the annual rainfall occurred during the wet season. However, the seasonal amplitude of volumetric soil water content (VSWC) increased from north to south, because of the increased potential for seasonal flooding. The vapor pressure deficit (VPD), air temperature, solar radiation (Rg) and net radiation (Rn) also increased from north to south, which directly affected the seasonal amplitude in the enhanced vegetation index (EVI). Our data suggest that energy partitioning in the wettest sites (AFL and CAM) were driven by solar radiation instead of soil water availability, while seasonal variation in rainfall was more important for the Amazon-Cerrado transitional forest (SIN), Cerrado (FMI and FEX) and Pantanal scrublands (BPE). These patterns are discernable using appropriate satellite vegetation indices, such as the EVI, allowing spatial and temporal variations in energy partitioning to be quantified across diverse landscapes like the Amazon Basin.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.DSR.2015.06.002", "year": 2015, "title": "Particle sources and downward fluxes in the eastern Fram strait under the influence of the west Spitsbergen current", "abstract": "The carbon cycle of the Arctic Ocean is tightly regulated by landatmospherecryosphereocean interactions. Characterizing these environmental exchanges and feedbacks is critical to facilitate projections of the carbon cycle under changing climate conditions. The environmental drivers of sinking particles including organic carbon (OC) to the deep-sea floor are investigated with four moorings including sediment traps and currentmeters at the Arctic gateway in the eastern Fram Strait, which is the area where warm anomalies are transported northwards to the Arctic. Particles fluxes were collected over one year (July 2010July 2011) and have been analysed to obtain the content of the lithogenic fraction, calcium carbonate, OC and its stable isotopes, opal, and the grain size. Records of near bottom current speed and temperature along with satellite observations of sea ice extent and chlorophyll-a concentration have been used for evaluation of the environmental conditions. We found increased lithogenic fluxes (up to 9872mgm2d1) and coarsening grain size of settling particles in late winterearly spring. At the same time, intensifications of the northward flowing west Spitsbergen current (WSC) were recorded. The WSC was able to resuspend and transport northwards sediments that were deposited at the outlet of Storfjordrenna and on the upper slope west of Spitsbergen. The signal of recurrent winnowing of fine particles was also detected in the top layer of surface sediments. In addition, an increased arrival of sea ice transported ice rafted detritus (>414 detrital carbonate mineral grains larger than 1mm per m2) from the southern Spitsbergen coast along with terrestrial organic matter was observed beyond 1000m of water depth during winter months. Finally, the downward particle fluxes showed typical temporal variability of high latitudes, with high percentages of the biogenic compounds (opal, organic carbon and calcium carbonate) linked to the phytoplankton bloom in springsummer. However, on an annual basis local planktonic production was a secondary source for the downward OC, since most of the OC was advected laterally by the WSC. Overall, these observations demonstrated the sensitivity of the downward flux of particles to environmental conditions such as hydrodynamics, sea ice rafting, and pelagic primary production. Future alteration of the patterns of natural drivers due to climate change is thus expected to cause major shifts in the downward flux of particles, including carbon, to the deep sea ecosystems.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-15-6159-2015", "year": 2015, "title": "Ozone and aerosol tropospheric concentrations variability analyzed using the ADRIMED measurements and the WRF and CHIMERE models", "abstract": "Abstract. During the months of June and July 2013, over the EuroMediterranean area, the ADRIMED (Aerosol Direct Radiative Impact on the regional climate in the MEDiterranean region) project was dedicated to characterize the ozone and aerosol concentrations in the troposphere. It is first shown that this period was not highly polluted compared to previous summers in this region, with a moderate ozone production, no significant vegetation fire events and several precipitation periods scavenging the aerosol. The period is modeled with the WRF (Weather Research and Forecasting) and CHIMERE models, and their ability to quantify the observed pollution transport events is presented. The CHIMERE model simulating all kinds of sources (anthropogenic, biogenic, mineral dust, vegetation fires); the aerosol speciation, not available with the measurements, is presented: during the whole period, the aerosol was mainly constituted by mineral dust, sea salt and sulfates close to the surface and mainly by mineral dust in the troposphere. Compared to the AERONET (Aerosol Robotic Network) size distribution, it is shown that the model underestimates the coarse mode near mineral dust sources and overestimates the fine mode in the Mediterranean area, highlighting the need to improve the model representation of the aerosol size distribution both during emissions, long-range transport and deposition.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1017/S0025315414001647", "year": 2015, "title": "Oceanographic scenario and fish larval distribution off Guinea-Bissau (north-west Africa)", "abstract": "This paper describes the hydrography and the larval fish assemblage of Guinea Bissau waters, and analyses the spatial distribution of the main families in relation to the oceanographic features of the area. Data were obtained during an oceanographic survey, undertaken between October and November 2008. In addition to 98 demersal fishing hauls, a total of 33 stations, located between 20 and 1000 m depth, were sampled for hydrography and ichthyoplankton. Data showed that Guinea-Bissauan surface waters are characterized by a strong thermohaline front that flows parallel to the bathymetry of the area. Warm surface waters (SST > 29C) occupy the inner shelf, and colder (SST ", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.AEOLIA.2015.07.009", "year": 2015, "title": "Observation and modeling of black soil wind-blown erosion from cropland in Northeastern China", "abstract": "As the nations bread basket, Northeastern China has experienced dramatic land use changes in the past decades, with much natural land being converted into cropland to feed the growing population. The long dormant season, coupled with frequent cold fronts and strong spring winds, makes the exposed cropland vulnerable to wind erosion. However, the rates and spatialtemporal characteristics of wind erosion in this particular soil type have been poorly studied. The present study aimed to measure and simulated the wind erosion characteristics from black soil cropland in the Dehui region of Northeastern China. Our results showed that wind-blown erosion was positively correlated with wind speed and negatively linked to soil moisture, vegetation and soil roughness in this region. The measured threshold friction velocity was 4.47m/s at 2m height, corresponding to 0.37m/s at the surface ground. Based on WRF-CMAQ-FENGSHA model, we localized the parameters and simulated a significant wind erosion event in the Dehui region on May 31, 2013. The relationships between modeled dust flux and ground measurement were correlated (R2=0.78). In addition, the modeled aerosol optical depths were also captured by satellite observations (MODIS and CALIPSO). Our results indicate that the bare farmland areas over Northeastern China are important dust sources over this region, and should not be neglected in regional air quality models. The use of protective farming techniques, protection of grassland and plowing in autumn for cropland areas should be considered to combat dust emission.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.JARIDENV.2015.01.008", "year": 2015, "title": "Newly desertified regions in Iraq and its surrounding areas: Significant novel sources of global dust particles", "abstract": "Using the newly developed Middle East Dust Index (MEDI) applied to MODIS satellite data, we consider a relationship between the recent desertified regions, over the past three decades, and the dust source points identified during the period of 20012012. Results indicate that major source points are located in Iraq and Syria, and by implementing the spectral mixture analysis on the Landsat TM images (1984 and 2012), a novel desertification map was extracted. Results of this study indicate for the first time that c.a., 39% of all detected source points are located in this newly anthropogenically desertified area. Using extracted indices for Deep Blue algorithm, dust sources were classified into three levels of intensity: low, medium, and high. A large number of low frequency sources are located within or close to the newly desertified areas. These severely desertified regions require immediate concern at a global scale.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS70810788", "year": 2015, "title": "Net Surface Shortwave Radiation from GOES ImageryProduct Evaluation Using Ground-Based Measurements from SURFRAD", "abstract": "The Earths surface net radiation controls the energy and water exchanges between the Earths surface and the atmosphere, and can be derived from satellite observations. The ability to monitor the net surface radiation over large areas at high spatial and temporal resolution is essential for many applications, such as weather forecasting, short-term climate prediction or water resources management. The objective of this paper is to derive the net surface radiation in the shortwave domain at high temporal (half-hourly) and spatial resolution (~1 km) using visible imagery from Geostationary Operational Environmental Satellite (GOES). The retrieval algorithm represents an adaptation to GOES data of a standard algorithm initially developed for the NASA-operated Clouds and Earths Radiant Energy System (CERES) scanner. The methodology relies on: (1) the estimation of top of atmosphere shortwave radiation from GOES spectral measurements; and (2) the calculation of net surface shortwave (SW) radiation accounting for atmospheric effects. Comparison of GOES-retrieved net surface shortwave radiation with ground-measurements at the National Oceanic and Atmospheric Administrations (NOAA) Surface Radiation (SURFRAD) stations yields very good agreement with average bias lower than 5 Wm2 and root mean square difference around 70 Wm2. The algorithm performance is usually higher over areas characterized by low spatial variability in term of land cover type and surface biophysical properties. The technique does not involve retrieval and assessment of cloud properties and can be easily adapted to other meteorological satellites around the globe.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S10113-014-0642-8", "year": 2015, "title": "Natural disasters and land-use/land-cover change in the southwest coastal areas of Bangladesh", "abstract": "Natural hazards and major land-use/land-cover change can have significant impacts on humans around the world. If these two concerns exist together in a coastal area, the consequences for people and the environment may be severe. This study investigated the combined effects of land-use changes and natural disasters in the southwest coastal area of Bangladesh. Satellite images were analyzed to detect changes in land cover in the study period of 13 years (19992012). Three areas were selected for ground data collection. Household surveys and focus groups were conducted to discover the type, level and effects of disasters. Probit regression analysis was performed to assess the relationship between various disasters with overall income, agricultural production and outward migration. Results from image analysis showed an overall 30 % increase in shrimp culture ponds in the past 13 years. Agricultural land and vegetation decreased by 48 and 3 %, respectively. Barren and built-up areas increased by 73 % due to both land-use activity and natural hazards. Analysis of household data showed cyclones and storm surges had important effects on income, agricultural production and migration. Sustainable management and enhancement of resilience capacity of this area will be crucial in the near future.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/ACP-15-5047-2015", "year": 2015, "title": "Molecular characterization of free tropospheric aerosol collected at the Pico Mountain Observatory: a case study with a long-range transported biomass burning plume", "abstract": "Abstract. Free tropospheric aerosol was sampled at the Pico Mountain Observatory located at 2225 m above mean sea level on Pico Island of the Azores archipelago in the North Atlantic. The observatory is located ~ 3900 km east and downwind of North America, which enables studies of free tropospheric air transported over long distances. Aerosol samples collected on filters from June to October 2012 were analyzed to characterize organic carbon, elemental carbon, and inorganic ions. The average ambient concentration of aerosol was 0.9 0.7 g m3. On average, organic aerosol components represent the largest mass fraction of the total measured aerosol (60 51%), followed by sulfate (23 28%), nitrate (13 10%), chloride (2 3%), and elemental carbon (2 2%). Water-soluble organic matter (WSOM) extracted from two aerosol samples (9/24 and 9/25) collected consecutively during a pollution event were analyzed using ultrahigh-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Approximately 4000 molecular formulas were assigned to each of the mass spectra in the range of m/z 1001000. The majority of the assigned molecular formulas had unsaturated structures with CHO and CHNO elemental compositions. FLEXPART retroplume analyses showed the sampled air masses were very aged (average plume age > 12 days). These aged aerosol WSOM compounds had an average O/C ratio of ~ 0.45, which is relatively low compared to O/C ratios of other aged aerosol. The increase in aerosol loading during the measurement period of 9/24 was linked to biomass burning emissions from North America by FLEXPART retroplume analysis and Moderate Resolution Imaging Spectroradiometer (MODIS) fire counts. This was confirmed with biomass burning markers detected in the WSOM and with the morphology and mixing state of particles as determined by scanning electron microscopy. The presence of markers characteristic of aqueous-phase reactions of phenolic species suggests that the aerosol collected at the Pico Mountain Observatory had undergone cloud processing before reaching the site. Finally, the air masses of 9/25 were more aged and influenced by marine emissions, as indicated by the presence of organosulfates and other species characteristic of marine aerosol. The change in the air masses for the two samples was corroborated by the changes in ethane, propane, and ozone, morphology of particles, as well as by the FLEXPART retroplume simulations. This paper presents the first detailed molecular characterization of free tropospheric aged aerosol intercepted at a lower free troposphere remote location and provides evidence of low oxygenation after long-range transport. We hypothesize this is a result of the selective removal of highly aged and polar species during long-range transport, because the aerosol underwent a combination of atmospheric processes during transport facilitating aqueous-phase removal (e.g., clouds processing) and fragmentation (e.g., photolysis) of components.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1002/2015JD023234", "year": 2015, "title": "Moisture sources and synoptic to seasonal variability of North Atlantic water vapor isotopic composition", "abstract": "AbstractThe isotopic composition of near surface (or planetary boundary layer) water vapor on the south coast of Iceland (63.83N, 21.47W) has been monitored in situ between November 2011 and April 2013. The calibrated data set documents seasonal variations in the relationship between 18O and local humidity (ppmv) and between deuterium excess and 18O. These seasonal variations are attributed to seasonal changes in atmospheric transport. A strong linear relationship is observed between deuterium excess and atmospheric relative humidity calculated at regional sea surface temperature. Surprisingly, we find a similar relationship between deuterium excess and relative humidity as observed in the Bermuda Islands. During days with low amount of isotopic depletion (more enriched values), our data significantly deviate from the global meteoric water line. This feature can be explained by a supply of an evaporative flux into the planetary boundary layer above the ocean, which we show using a 1-d box model. Based on the close relationship identified between moisture origin and deuterium excess, we combine deuterium excess measurements performed in Iceland and south Greenland with moisture source diagnostics based on back trajectory calculations to establish the distribution of d-excess moisture uptake values across the North Atlantic. We map high deuterium excess in the Arctic and low deuterium excess for vapor in the subtropics and midlatitudes. This confirms the role of North Atlantic water vapor isotopes as moisture origin tracers.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-15-7471-2015", "year": 2015, "title": "Modulation of Saharan dust export by the North African dipole", "abstract": "Abstract. We have studied the relationship between the long-term interannual variability in large-scale meteorology in western North Africa the largest and most active dust source worldwide and Saharan dust export in summer, when enhanced dust mobilization in the hyper-arid Sahara results in maximum dust impacts throughout the North Atlantic. We address this issue by analyzing 28 years (19872014) of summer averaged dust concentrations at the high-altitude Izana observatory (~ 2400 m a.s.l.) on Tenerife, and satellite and meteorological reanalysis data. The summer meteorological scenario in North Africa (aloft 850 hPa) is characterized by a high over the the subtropical Sahara and a low over the tropics linked to the monsoon. We measured the variability of this highlow dipole-like pattern in terms of the North African dipole intensity (NAFDI): the difference of geopotential height anomalies averaged over the subtropics (3032 N, Morocco) and the tropics (1013 N, Bamako region) close to the Atlantic coast (at 58 W). We focused on the 700 hPa standard level due to dust export off the coast of North Africa tending to occur between 1 and 5 km a.s.l. Variability in the NAFDI is associated with displacements of the North African anticyclone over the Sahara and this has implications for wind and dust export. The correlations we found between the 19872014 summer mean of NAFDI with dust at Izana, satellite dust observations and meteorological re-analysis data indicate that increases in the NAFDI (i) result in higher wind speeds at the north of the Inter-Tropical Convergence Zone that are associated with enhanced dust export over the subtropical North Atlantic, (ii) influence the long-term variability of the size distribution of exported dust particles (increasing the load of coarse dust) and (iii) are associated with enhanced rains in the tropical and northern shifts of the tropical rain band that may affect the southern Sahel. Interannual variability in NAFDI is also connected to spatial distribution of dust over the North Atlantic; high NAFDI summers are associated with major dust export (linked to winds) in the subtropics and minor dust loads in the tropics (linked to higher rainfall), and vice versa. The evolution of the summer NAFDI values since 1950 to the present day shows connections to climatic variability (through the Sahelian drought, ENSO (El NinoSouthern Oscillation) and winds) that have implications for dust export paths. Efforts to anticipate how dust export may evolve in future decades will require a better understanding of how the large-scale meteorological systems represented by the NAFD will evolve.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10661-015-5041-1", "year": 2015, "title": "MODIS-Aqua detects Noctiluca scintillans and hotspots in the central Arabian Sea", "abstract": "Northern Arabian Sea is considered as an ecologically sensitive area as it experiences a massive upwelling and long-lasting algal bloom, Noctiluca scintillans (green tide) during summer and spring-winter, respectively. Diatom bloom is also found to be co-located with N. scintillans and both have an impact on ecology of the basin. In-house technique of detecting species of these blooms from Moderate Resolution Imaging Spectroradiometer (MODIS)-Aqua data was used to generate a time-series of images revealing their spatial distribution. A study of spatial-temporal variability of these blooms using satellite data expressed a cyclic pattern of their spread over a period of 13 years. An average distribution of the blooms for JanuaryMarch period revealed a peak in 2015 and minimum in 2013. Subsequently, a time-series of phytoplankton species images were generated for these 2 years to study their inter-annual variability and the associated factors. Species images during active phase of the bloom (February) in 2015 indicated development of N. scintillans and diatom in the central Arabian Sea also, up to 12 N. This observation was substantiated with relevant oceanic parameters measured from the ship as well as satellite data and the same is highlight of the paper. While oxygen depletion and release of ammonia associated with N. scintillans are detrimental for waters on the western side; it is relatively less extreme and supports the entire food chain on the eastern side. In view of these contrasting eco-sensitive events, it is a matter of concern to identify biologically active persistent areas, hot spots, in order to study their ecology in detail. An ecological index, persistence of the bloom, was derived from the time-series of species images and it is another highlight of our study.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S13351-015-5043-5", "year": 2015, "title": "Modification of cumulus convection and planetary boundary layer schemes in the GRAPES global model", "abstract": "Cumulus convection is a key linkage between hydrological cycle and large-scale atmospheric circulation. Cumulus parameterization scheme is an important component in numerical weather and climate modeling studies. In the Global/Regional Assimilation and Prediction Enhanced System (GRAPES), turbulent mixing and diffusion approach is applied in its shallow convection scheme. This method overestimates the vertical transport of heat and moisture fluxes but underestimates cloud water mixing ratio over the region of stratocumulus clouds. As a result, the simulated low stratocumulus clouds are less than observations. To overcome this problem, a mass flux method is employed in the shallow convection scheme to replace the original one. Meanwhile, the deep convection scheme is adjusted correspondingly. This modification is similar to that in the US NCEP Global Forecast System (GFS), which uses the simplified Arakawa Schubert Scheme (SAS). The planetary boundary layer scheme (PBL) is also revised by considering the coupling between the PBL and stratocumulus clouds. With the modification of both the cumulus and PBL schemes, the GRAPES simulation of shallow convective heating rate becomes more reasonable; total amounts of stratocumulus clouds simulated over the eastern Pacific and their vertical structure are more consistent with observations; the underestimation of stratocumulus clouds simulated by original schemes is less severe with the revised schemes. Precipitation distribution in the tropics becomes more reasonable and spurious precipitation is effectively suppressed. The westward extension and northward movement of the western Pacific subtropical high simulated with the revised schemes are more consistent with Final Operational Global Analysis (FNL) than that simulated with the original schemes. The statistical scores for the global GRAPES forecast are generally improved with the revised schemes, especially for the simulation of geopotential height in the Northern Hemisphere and winds in the tropics. Root mean square errors (RMSEs) decrease in the lower and upper troposphere with the revised schemes. The above results indicate that with the revised cumulus and PBL schemes, model biases in the tropics decrease and the global GRAPES performance is greatly improved.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/QJ.2542", "year": 2015, "title": "Modeling the effects of dust-radiative forcing on the movement of Hurricane Helene (2006)", "abstract": "The influence of direct dust-radiative forcing on the movement and track of Hurricane Helene (2006) is examined numerically using the Weather Research and Forecasting dust model. Numerical simulations show that the model-generated dust plume modifies the thermal field, causing a clockwise turning of the vertical shear surrounding the plume, which changes the deep layer steering flow. The change in the steering flow modifies Helene's moving speed and direction as it transits the plume. As Helene exits the plume, it has a different trajectory than it would have had in the absence of dust-radiative forcing. Consequently, the difference in the tracks with and without dust-radiative forcing continues to grow with distance from the plume. The dust-induced changes in temperature and wind together cause Helene's modeled storm track to be in closer agreement with the observed track; the dust-radiative forcing reduces the error in the model's 7-day track forecasts by an average of 27% (205 km).", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1364/OE.23.023924", "year": 2015, "title": "Modeling daytime sky access for a satellite quantum key distribution downlink", "abstract": "Daytime sky radiance can lead to quantum-bit-error rates (QBER) sufficiently high to preclude quantum key distribution over satellite-to-Earth downlinks. For circular orbits, sky radiance and propagation losses are both pointing-angle-dependent quantities. This dependence makes it possible to map the sky as a function of the QBER in certain protocols. Sky radiance distributions are generated by libRadtran software with aerosol values representative of summer and winter. Hemispherical maps of the QBER are created for orbit altitudes of 400 and 800 km. Sunrise-to-sunset simulations are presented for a system with commercial optical components and compared to a case employing an atomic-line spectral filter.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.MARCHEM.2015.06.024", "year": 2015, "title": "Microbial community composition and nitrogen availability influence DOC remineralization in the South Pacific Gyre", "abstract": "Many environmental factors are thought to control the bioavailability of marine dissolved organic matter (DOM) for marine microbes including its composition, the microbial community structure, and nutrient availability, yet which factors dominate at the ocean basin scale remains uncertain. Understanding the controls on DOM lability is an important goal given the role of DOM in the marine carbon cycle. We performed DOM lability experiments at two contrasting stations, one oligotrophic and one mesotrophic, in the eastern tropical South Pacific (ETSP) to investigate the controls on microbial remineralization of surface ocean DOM. Surface layer dissolved organic carbon (DOC) and nitrogen (DON) were recalcitrant to remineralization over 9 to 14days when exposed to the microbial communities from the surface mixed layer, however exposure to microbial communities from the upper mesopelagic (twilight zone) allowed consumption of DOC but not DON. The DOC remineralization response differed between the mesotrophic site (~21M consumed), likely experiencing allochthonous inputs of DOM from the adjacent eastern boundary upwelling system, versus the oligotrophic station (~3M consumed) further offshore in the South Pacific gyre. DNA fingerprinting of the microbial communities across the ETSP with terminal restriction fragment length polymorphism (T-RFLP) analyses revealed greater differences between microbial communities in surface vs. subsurface (e.g., 100m) waters at the same station than between surface water microbial communities separated by 1000s of kilometers. The subsurface microbial community at the mesotrophic station responsible for the greatest observed DOC remineralization, with a concomitant consumption of nitrate, consumed DOC to concentrations below that observed in situ (at 100m), suggesting a potential role for co-metabolism of relatively labile with more recalcitrant DOC or relief from micronutrient limitation, in driving the additional DOC consumption. DOC remineralization by the mesopelagic (200m) microbial community was much less at the oligotrophic station and similar to previously published results from the Sargasso Sea. Both microbial community composition and nutrient availability contribute to DOM persistence over weekly timescales in the surface mixed layer with varying degrees of DOC lability in the subsurface waters of the ETSP.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.AEOLIA.2015.01.006", "year": 2015, "title": "Meteorological, atmospheric and climatic perturbations during major dust storms over Indo-Gangetic Basin", "abstract": "During the pre-monsoon season (AprilJune), the Indo-Gangetic Basin (IGB) suffers from frequent and intense dust storms originated from the arid and desert regions of southwest Asia (Iran, Afghanistan), Arabia and Thar desert blanketing IGB and Himalayan foothills. The present study examines the columnar and vertical aerosol characteristics and estimates the shortwave (0.254.0m) aerosol radiative forcing (ARF) and atmospheric heating rates over Kanpur, central IGB, during three intense dust-storm events in the pre-monsoon season of 2010. MODIS images, meteorological and AERONET observations clearly show that all the dust storms either originated from the Thar desert or transported over, under favorable meteorological conditions (low pressure and strong surface winds) affecting nearly the whole IGB and modifying the aerosol loading and characteristics (Angstrom exponent, single scattering albedo, size distribution and refractive index). CALIPSO observations reveal the presence of high-altitude (up to 35km) dust plumes that strongly modify the vertical aerosol profile and are transported over Himalayan foothills with serious climate implications (atmospheric warming, enhanced melting of glaciers). Shortwave ARF calculations over Kanpur using SBDART model show large negative forcing values at the surface (93.27, 101.60 and 66.71Wm2) during the intense dusty days, associated with planetary (top of atmosphere) cooling (18.16, 40.95, 29.58Wm2) and significant atmospheric heating (75.11, 60.65, 37.13Wm2), which is translated to average heating rates of 1.57, 1.41 and 0.78Kday1, respectively in the lower atmosphere (below 3.5km). The ARF estimates are in satisfactory agreement with the AERONET ARF retrievals over Kanpur.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.AEOLIA.2015.06.006", "year": 2015, "title": "Meteorological regimes modulating dust outbreaks in southwest Asia: The role of pressure anomaly and Inter-Tropical Convergence Zone on the 13 July 2014 case", "abstract": "The present work examines the characteristics (source regions, pathways, vertical profiles) as well as the meteorological conditions and the role of the Inter-Tropical Convergence Zone (ITCZ) during a dust event on 13 July 2014 over southwest (SW) Asia. NCEP/NCAR reanalysis, meteorological and satellite remote sensing (MODIS, Meteosat, CALIPSO) observations are utilized. The major dust storm (AOD550 up to 1.52.0) was generated in the southern Karakum desert in Turkmenistan as a result of intense north winds (Levar), due to enhanced pressure gradient between the Caspian Sea and Hindu Kush Mountains. The dust storm was vertically extended up to 5km over the arid terrain of SW Asia, as a consequence of the deep mixing layer and increased convection, while over northern Arabian Sea it was mixed with another dust plume coming from Arabia and marine aerosols due to strong monsoon winds within the boundary layer. The regional topography, variations in pressure, monsoon circulation and the position of the ITCZ play a decisive role on modulation of the wind field, dust-storm pathways and vertical distribution of dust. Enhanced knowledge of atmospheric circulation and processes responsible for dust export over SW Asia and Arabian Sea in linkage to the Levar wind and Indian summer monsoon is essential for improving dust forecasts and simulations over the region.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ECOLMODEL.2015.06.040", "year": 2015, "title": "Mathematical modelling of the seasonal variability of plankton and forage fish in the Gulf of Kachchh", "abstract": "Seasonal variability of plankton and small fish in the coastal water of west coast of India is studied with a non-linear mathematical model (NPZF model) having four compartments viz., nutrient, phytoplankton, zooplankton and forage fish. The inclusion of an additional compartment of forage fish increases the complexity of the earlier proposed NPZ model as it introduces additional seven unknown parameters, which need to be specified for performing numerical simulations. The key problem is therefore to estimate the range of values of these parameters in the dynamical system. With the help of local stability analysis, sensitivity analysis and numerical simulations, these parameters have been estimated. As a case study for the evaluation of the model, simulations are performed to explain the aquatic ecology of Gulf of Kachchh (2220 N2340 N, 6820 E7040 E), an inlet on west coast of India in the Arabian Sea. An important conclusion of this study is that by using the prescribed parameters as estimated from the sensitivity analysis, the NPZF model reproduces some salient features of the Gulf of Kachchh, especially the bimodal oscillations observed in the plankton and forage fish. The 4-compartment model could therefore serve as an ecological model of the Gulf of Kuchchh.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/2014JC010591", "year": 2015, "title": "Marine climate influences on interannual variability of tropical cyclones in the eastern Caribbean: 19792008", "abstract": "Interannual variability of tropical cyclones (TCs) in the eastern Caribbean is studied using MIT-Hurdat fields during the JulyOctober season from 1979 to 2008. TC intensity shows local climate sensitivity particularly for upper ocean currents, salinity and mixed-layer depth, and 200850 mb wind shear. Remote influences from the Southern Oscillation, Saharan dust, and the South American monsoon are also identified as important. Ocean currents diminish along the coast of South America, so interbasin transfer between the North Brazil and Caribbean Currents declines in seasons of frequent and intense TCs. This is related to a dipole pattern in the sea surface height formed mainly by reduced trade wind upwelling northeast of Venezuela. A low-salinity plume from the Orinoco River spreads across the eastern Caribbean. It is the weaker currents and shallower mixed layer that conspire with surplus heat to build thermodynamic energy available for TC intensification.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1134/S0001437015010087", "year": 2015, "title": "Manifestations of the rim current, coccolithophore blooms, and continental runoff in the long-term monthly mean distributions of satellite reflectance coefficients of the Black Sea", "abstract": "Based on the archived data of the ocean color scanner MODIS-Aqua for 20032011, we constructed the long-term monthly mean distributions of the reflectance Rrs of the Black Sea for April, May, June, and September in order to visualize the contributions of seasonal factors to the long-term variability of the basins images. In April, the Rim Currents branch west of 34 E is visualized by higher Rrs in different regions of the visible spectrum due to the transport of suspended matter caused by intensification of the Rim Current during the winter-spring period. During the June coccolithophore blooms, the long-term Rrs level is 23 times higher when compared to the previous and subsequent months. This excess is particularly considerable outside the shelf and coastal areas. The open sea Rrs distribution in June features horizontal inhomogeneity. The seasonal trend of the Rrs spectra on the Black Sea NW shelf is explicitly related to the annual cycle of the continental runoff effects.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SEARES.2015.06.018", "year": 2015, "title": "Life in the sea of plenty: Seasonal and regional comparison of physiological performance of Euphausia hanseni in the northern Benguela upwelling system", "abstract": "Variability in upwelling events may lead to periods of constrained food availability in the northern Benguela upwelling system (NBUS), thereby affecting the physiological state and metabolic activity of euphausiids. Most attention has so far been paid to seasonal effects but little is known about regional variability. Metabolic activity (expressed by respiration and excretion rates) and physiological state (expressed by reproductive effort and moult activity) in Euphausia hanseni were examined at different stations during austral summer (minimum upwelling) and austral winter (maximum upwelling). Overall, regional differences in physiological state, influencing metabolic activity, were greater than seasonal ones, indicating favourable conditions for growth and reproduction year-round. Higher respiration rates were found for females in more advanced stages of sexual development. Moult stage did not affect oxygen consumption rates, however. The physiological state of E. hanseni at the time of capture may serve as a meaningful indicator of the associated hydrographic conditions in the NBUS, to be further used in eco-system analysis on seasonal or long-term time scales. A latitudinal comparison of species highlights the extraordinary physiological plasticity of euphausiids.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/BG-12-5309-2015", "year": 2015, "title": "Latitudinal and temporal distributions of diatom populations in the pelagic waters of the Subantarctic and Polar Frontal zones of the Southern Ocean and their role in the biological pump", "abstract": "Abstract. The Subantarctic and Polar Frontal zones (SAZ and PFZ) represent a large portion of the total area of the Southern Ocean and serve as a strong sink for atmospheric CO2. These regions are central to hypotheses linking particle fluxes and climate change, yet multi-year records of modern flux and the organisms that control it are, for obvious reasons, rare. In this study, we examine two sediment trap records of the flux of diatoms and bulk components collected by two bottom-tethered sediment traps deployed at mesopelagic depths (~ 1 km) in the SAZ (2-year record; July 1999October 2001) and in the PFZ (6-year record; September 1997February 1998, July 1999August 2000, November 2002October 2004 and December 2005October 2007) along the 140 E meridian. These traps provide a direct measure of transfer below winter mixed layer depths, i.e. at depths where effective sequestration from the atmosphere occurs, in contrast to study of processes in the surface ocean. Total mass fluxes were about twofold higher in the PFZ (24 13 g m2 yr1) than in the SAZ (14 2 g m2 yr1). Bulk chemical composition of the particle fluxes mirrored the composition of the distinct plankton communities of the surface layer, being dominated by carbonate in the SAZ and by biogenic silica in the PFZ. Particulate organic carbon (POC) export was similar for the annual average at both sites (1.0 0.1 and 0.8 0.4 g m2 yr1 for the PFZ and SAZ, respectively), indicating that the particles in the SAZ were relatively POC rich. Seasonality in the particle export was more pronounced in the PFZ. Peak fluxes occurred during summer in the PFZ and during spring in the SAZ. The strong summer pulses in the PFZ are responsible for a large fraction of the variability in carbon sequestration from the atmosphere in this region. The latitudinal variation of the total diatom flux was found to be in line with the biogenic silica export with an annual flux of 31 5.5 108 valves m2 yr1 at the PFZ compared to 0.5 0.4 108 m2 yr1 at the SAZ. Fragilariopsis kerguelensis dominated the annual diatom export at both sites (43 % at the SAZ and 59 % in the PFZ). POC fluxes displayed a strong positive correlation with the relative contribution of a group of weakly silicified and bloom-forming species in the PFZ. Several lines of evidence suggests that the development of these species during the growth season facilitates the formation of aggregates and carbon export. Our results confirm previous work suggesting that F. kerguelensis plays a major role in the decoupling of the carbon and silicon cycles in the high-nutrient low-chlorophyll waters of the Southern Ocean.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1371/JOURNAL.PONE.0118390", "year": 2015, "title": "Large-Scale Geographic Variation in Distribution and Abundance of Australian Deep-Water Kelp Forests", "abstract": "Despite the significance of marine habitat-forming organisms, little is known about their large-scale distribution and abundance in deeper waters, where they are difficult to access. Such information is necessary to develop sound conservation and management strategies. Kelps are main habitat-formers in temperate reefs worldwide; however, these habitats are highly sensitive to environmental change. The kelp Ecklonia radiate is the major habitat-forming organism on subtidal reefs in temperate Australia. Here, we provide large-scale ecological data encompassing the latitudinal distribution along the continent of these kelp forests, which is a necessary first step towards quantitative inferences about the effects of climatic change and other stressors on these valuable habitats. We used the Autonomous Underwater Vehicle (AUV) facility of Australias Integrated Marine Observing System (IMOS) to survey 157,000 m2 of seabed, of which ca 13,000 m2 were used to quantify kelp covers at multiple spatial scales (10100 m to 1001,000 km) and depths (1560 m) across several regions ca 26 latitude apart along the East and West coast of Australia. We investigated the large-scale geographic variation in distribution and abundance of deep-water kelp (>15 m depth) and their relationships with physical variables. Kelp cover generally increased with latitude despite great variability at smaller spatial scales. Maximum depth of kelp occurrence was 4050 m. Kelp latitudinal distribution along the continent was most strongly related to water temperature and substratum availability. This extensive survey data, coupled with ongoing AUV missions, will allow for the detection of long-term shifts in the distribution and abundance of habitat-forming kelp and the organisms they support on a continental scale, and provide information necessary for successful implementation and management of conservation reserves.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-15-6651-2015", "year": 2015, "title": "Lagrangian analysis of microphysical and chemical processes in the Antarctic stratosphere: a case study", "abstract": "Abstract. We investigated chemical and microphysical processes in the late winter in the Antarctic lower stratosphere, after the first chlorine activation and initial ozone depletion. We focused on a time interval when both further chlorine activation and ozone loss, but also chlorine deactivation, occur. We performed a comprehensive Lagrangian analysis to simulate the evolution of an air mass along a 10-day trajectory, coupling a detailed microphysical box model to a chemistry model. Model results have been compared with in situ and remote sensing measurements of particles and ozone at the start and end points of the trajectory, and satellite measurements of key chemical species and clouds along it. Different model runs have been performed to understand the relative role of solid and liquid polar stratospheric cloud (PSC) particles for the heterogeneous chemistry, and for the denitrification caused by particle sedimentation. According to model results, under the conditions investigated, ozone depletion is not affected significantly by the presence of nitric acid trihydrate (NAT) particles, as the observed depletion rate can equally well be reproduced by heterogeneous chemistry on cold liquid aerosol, with a surface area density close to background values. Under the conditions investigated, the impact of denitrification is important for the abundances of chlorine reservoirs after PSC evaporation, thus stressing the need to use appropriate microphysical models in the simulation of chlorine deactivation. We found that the effect of particle sedimentation and denitrification on the amount of ozone depletion is rather small in the case investigated. In the first part of the analyzed period, when a PSC was present in the air mass, sedimentation led to a smaller available particle surface area and less chlorine activation, and thus less ozone depletion. After the PSC evaporation, in the last 3 days of the simulation, denitrification increases ozone loss by hampering chlorine deactivation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSRES.2015.03.010", "year": 2015, "title": "Investigation of sea-breeze convergence in Salento Peninsula (southeastern Italy)", "abstract": "The frequency, the location and the characteristics of convective rainfall events induced by the convergence of different sea breeze systems on a Mediterranean peninsula (Salento, in southeastern Italy) are analyzed. Such events have been studied considering satellite/radar images and output fields from two Limited Area Models in the summer period of 20112013. A total of 20days have been detected in which the precipitation due to sea-breeze convergence was clearly observed in satellite and radar images. The synoptic conditions associated with these events have been identified considering the averages of some relevant meteorological parameters in the selected days and the anomaly with respect to the climate. The presence of a cold trough in the central Mediterranean basin appears as a fundamental ingredient for the occurrence of sea breeze convergence and associated precipitation. High-resolution simulations with two state-of-art numerical models have revealed that both of them are generally able to simulate a convergence pattern correctly, apart from a couple of cases for each model. The higher rainfall amounts occur with weak synoptic wind, and weak-to-moderate values of Convective Available Potential Energy (CAPE). When the synoptic wind is of moderate intensity, the region of convergence moves toward the Adriatic coast for a prevailing southerly component, and toward the Ionian coast for a prevailing northerly component. On the opposite, the skin sea surface temperature is relatively uniform and the difference between the Ionian and the Adriatic Seas, surrounding the peninsula on the east and west side, is generally smaller than 1K, having only a marginal effect on the sea breeze patterns. Similarly, the value of CAPE before the occurrence of rainfall has low prognostic value. The results shows that limited area models with a grid spacing of few km appear as appropriate tools for the simulation for such relatively small scale phenomena.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SEARES.2015.09.007", "year": 2015, "title": "Interannual variability in chlorophyll-a on the southern Queensland continental shelf and its relationship to ENSO", "abstract": "Coastal phytoplankton blooms can result from upwelling of colder nutrient-rich water, seasonal fluvial or anthropogenic point sources of nutrient. Here we analyze 15-year time series of monthly mean and 8-day satellite-derived chlorophyll-a (Chl-a) and sea surface temperature (SST) on the southern Queensland continental shelf (24.2528.25S) from March 2000 to February 2015. We examine the interannual variability in these parameters and its relationship to algal bloom dynamics. Seasonal climatological means are computed and analyzed. Empirical orthogonal function (EOF) analysis is applied to these time series. Cross-correlation and spatial correlation analyses are used to investigate the relationship between the multivariate ENSO index (MEI), Chl-a and SST. Computed eigenvectors of the time series of Chl-a and SST present a strong seasonal variability on the first EOF modes. Thus, the seasonal variability was removed by computing monthly and 8-day Chl-a and SST anomalies. The EOF analysis was then applied to the anomaly time series. Correlation analysis results show a positive correlation between MEI and the eigenvector of the first EOF of the monthly Chl-a anomaly with time lag of three to four months. We find a negative correlation between MEI and the eigenvector of the second EOF of the monthly Chl-a anomaly with time lag of three to four months. There is no correlation between MEI and eigenvectors of the monthly SST anomaly. There are significant correlations between eigenvectors of the first and second EOF modes of 8-day Chl-a and the first and second EOF modes of 8-day SST respectively. Negative correlation coefficients between 8-day anomalies of Chl-a and SST are found on the continental shelf to the east of Fraser Island and Stradbroke Island. Analysis of a particular algal bloom event indicates a negative SST anomaly and negative curl of wind stress in the waters to the southeast of Fraser Island suggesting that wind stress is possibly a secondary but significant physical driver of the upwelling system. Our results suggest that variability in phytoplankton biomass on the southern Queensland continental shelf is driven by upwelling of nutrients during the spring dry season and fluvial nutrient loads during the summer and autumn wet seasons. Seasonal change is the primary factor controlling the variability of Chl-a and SST while climate variability (ENSO) and upwelling are secondary but significant factors.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSENV.2015.02.027", "year": 2015, "title": "Influence of air mass origin on aerosol properties at a remote Michigan forest site", "abstract": "The northern Great Lakes region of North America is a large, relatively pristine area. To date, there has only been limited study of the atmospheric aerosol in this region. During summer 2009, a detailed characterization of the atmospheric aerosol was conducted at the University of Michigan Biological Station (UMBS) as part of the Community AtmosphereBiosphere Interactions Experiment (CABINEX). Measurements included particle size distribution, water-soluble composition, and CCN activity. Aerosol properties were strongly dependent on the origin of the air masses reaching the site. For 60% of the study period, air was transported from sparsely populated regions to the northwest. During these times aerosol loadings were low, with mean number and volume concentrations of 1630 cm3 and 1.91 m3 cm3, respectively. The aerosol during clean periods was dominated by organics, and exhibited low hygroscopicities (mean = 0.18 at s = 0.3%). When air was from more populated regions to the east and south (29% of the time), aerosol properties reflected a stronger anthropogenic influence, with 85% greater particle number concentrations, 2.5 times greater aerosol volume, six times more sulfate mass, and increased hygroscopicity (mean = 0.24 at s = 0.3%). These trends are have the potential to influence forestatmosphere interactions and should be targeted for future study.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1080/01431161.2015.1041174", "year": 2015, "title": "Influence of acquisition time and resolution on wheat yield estimation at the field scale from canopy biophysical variables retrieved from SPOT satellite data", "abstract": "Detailed information about the prediction of within-field potential in terms of yield at the field scale is an attractive goal that would allow useful applications in precision agriculture. Biophysical variables characterizing crop canopies, such as the leaf area index (LAI), fraction of absorbed photosynthetically active radiation (FAPAR), fractional ground cover (Fcover) and the concentration of chlorophyll-a and -b (Cab), can be estimated from satellite remote-sensing data through the application of a neural network inversion of a radiative transfer model, such as PROSAIL. The knowledge of the temporal and spatial variability of these variables can enhance the possibilities of estimating yield at the field scale. The aim of this study is to investigate the influence of acquisition time and spatial resolution of biophysical variables estimated from satellite data on the grain yield estimation of wheat crops. We used SPOT 4 (spatial resolution: 20 m) and SPOT 5 (spatial resolution: 10 m) images, acquired at six different dates during the wheat growing season in 2012, to obtain LAI, Fcover, FAPAR, and Cab on five fields in Maccarese (Central Italy). A preliminary survey was carried out to correlate spatially biophysical variables with the final grain yield at each acquisition date. Biophysical variables estimated at a spatial resolution of 10 m during the stem elongation stage showed the best simple and spatial correlation with yield. At this stage, all the biophysical variables showed the highest correlation values as compared to the other dates. Subsequently, we used the variables estimated from SPOT data at each growth stage to calibrate multiple linear regression (MLR) and cubist regression (CR) models for two fields, which were then validated on five independent fields. Although the CR calibration models provided better accuracy than MLR, the best validation statistics were gained from MLR models, obtaining a root mean square error (RMSE) of about 1 t ha1 for three of these fields, using remote data having a spatial resolution of 10 metres and acquired between steam elongation and booting stage. The optimal acquisition time is affected, ceteris paribus, by the agricultural management and in particular by the variety that can influence the trend of crop growth. However, the optimal growth stage for yield estimation seems to be quite similar over the study area during a growth season. The validation of models on field data collected in another growing season is mainly affected by the climate conditions. These results highlight the importance of spatial resolution and the influence of acquisition time of satellite images on the estimation of yield at the field scale by remote-sensing data.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.ECSS.2015.03.027", "year": 2015, "title": "In situ response of bay productivity to nutrient loading from a small tributary: The Delaware Bay-Murderkill Estuary tidally-coupled biogeochemical reactor", "abstract": "A small, turbid and nutrient-rich tributary, the Murderkill Estuary, and a large estuarine ecosystem, the Delaware Bay, are tightly linked and form an efficient, tidally-coupled biogeochemical reactor during the summer. Nitrate loading from the Murderkill Estuary generates an instantaneous increase in biological oxygen production in the adjacent Delaware Bay. We are able to capture this primary production response with continuous hourly measurements of dissolved oxygen, chlorophyll, and nitrate. The nitrate influxes from the Murderkill support primary production rates in the Delaware Bay margins that are twice as high as the average production rates measured in the central Bay regions. This elevates chlorophyll in the Bay margins in the summer and fuels metabolism. Tidal transport of the newly produced autochthonous chlorophyll particles from the Bay into the Estuary could also provide a source of labile material to the marshes surrounding the Murderkill, thus perhaps fueling marsh respiration. As a consequence of the tidal coupling between Delaware Bay and the Murderkill Estuary, ecosystem productivity and metabolism in the Bay and Estuary are linked, generating an ecosystem feedback mechanism. Storms modulate this tidally-coupled biogeochemical reactor, by generating significant nitrate and salinity changes. Depending on their magnitude and duration, storms induce large phytoplankton blooms in the Delaware Bay. Such large phytoplankton blooms may occur more often with climate change, since century-long discharge records document an increase in storm frequency.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5094/APR.2015.054", "year": 2015, "title": "Implications of MODIS impression of aerosol loading over urban and rural settlements in Nigeria: Possible links to energy consumption patterns in the country", "abstract": "A study of aerosol loading patterns in some selected cities in Nigeria was carried out using MODIS, TOMS/OMI AND AIRS satellite imageries for a period of 10 years. The results showed that an aerosol optical depth (AOD) loading obtained ranged from 0.020.9, UV aerosol index (AI) and carbon monoxide (CO) results ranged from 1.32 2.43 and 2.222.6 molecule/cm2, respectively. The CO data was used to infer the presence of carbonecous aerosols from biomass, fossil combustion and industrial activities. This result indicates that areas with higher AOD and AI do not correspond in high CO loading. From the HYSPLIT and HAT analysis conducted it showed that advection plays important role in the dispersion of aerosols. This implies that aerosols can reside in a place remote from where they are generated. Also, the high concentration of CO aerosol in the southern cities suggests a high rate of industrial pollution as a result of fossil fuel burning, vehicular emissions, high population density and gas flaring. Therefore, emphasis should be on the need to switch to renewable energy options as an alternative to fossil fuel. Furthermore, plans for mitigations should not be limited to industrialized cities only but extended to other cities which might be bearing the real brunt of industrial emissions as shown in this work.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-15-12251-2015", "year": 2015, "title": "Impacts of Amazonia biomass burning aerosols assessed from short-range weather forecasts", "abstract": "Abstract. The direct radiative impacts of biomass burning aerosols (BBA) on meteorology are investigated using short-range forecasts from the Met Office Unified Model (MetUM) over South America during the South American Biomass Burning Analysis (SAMBBA). The impacts are evaluated using a set of three simulations: (i) no aerosols, (ii) with monthly mean aerosol climatologies and (iii) with prognostic aerosols modelled using the Coupled Large-scale Aerosol Simulator for Studies In Climate (CLASSIC) scheme. Comparison with observations show that the prognostic CLASSIC scheme provides the best representation of BBA. The impacts of BBA are quantified over central and southern Amazonia from the first and second day of 2-day forecasts during 14 September3 October 2012. On average, during the first day of the forecast, including prognostic BBA reduces the clear-sky net radiation at the surface by 15 1 W m2 and reduces net top-of-atmosphere (TOA) radiation by 8 1 W m2, with a direct atmospheric warming of 7 1 W m2. BBA-induced reductions in all-sky radiation are smaller in magnitude: 9.0 1 W m2 at the surface and 4.0 1 W m2 at TOA. In this modelling study the BBA therefore exert an overall cooling influence on the Earthatmosphere system, although some levels of the atmosphere are directly warmed by the absorption of solar radiation. Due to the reduction of net radiative flux at the surface, the mean 2 m air temperature is reduced by around 0.1 0.02 C. The BBA also cools the boundary layer (BL) but warms air above by around 0.2 C due to the absorption of shortwave radiation. The overall impact is to reduce the BL depth by around 19 8 m. These differences in heating lead to a more anticyclonic circulation at 700 hPa, with winds changing by around 0.6 m s1. Inclusion of climatological or prognostic BBA in the MetUM makes a small but significant improvement in forecasts of temperature and relative humidity, but improvements were small compare with model error and the relative increase in forecast skill from the prognostic aerosol simulation over the aerosol climatology was also small. Locally, on a 150 km scale, changes in precipitation reach around 4 mm day1 due to changes in the location of convection. Over Amazonia, including BBA in the simulation led to fewer rain events that were more intense. This change may be linked to the BBA changing the vertical profile of stability in the lower atmosphere. The localised changes in rainfall tend to average out to give a 5 % (0.06 mm day1) decrease in total precipitation over the Amazonian region (except on day 2 with prognostic BBA). The change in water budget from BBA is, however, dominated by decreased evapotranspiration from the reduced net surface fluxes (0.2 to 0.3 mm day1), since this term is larger than the corresponding changes in precipitation and water vapour convergence.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.4209/AAQR.2015.05.0380", "year": 2015, "title": "Impact of Meteorological Parameters and Gaseous Pollutants on PM2.5 and PM10 Mass Concentrations during 2010 in Xian, China", "abstract": "ABSTRACTMass concentrations of PM2.5 and PM10 from the six urban/rural sampling sites of Xian were obtained during two weeks of every month corresponding to January, April, July and October during 2010, together with the six meteorological parameters and the data of two precursors. The result showed that the average annual mass concentrations of PM2.5 and PM10 were 140.9 108.9 g m3 and 257.8 194.7 g m3, respectively. Basin terrain constrains the diffusion of PM2.5 and PM10 concentration spatially. High concentrations in wintertime and low concentrations in summertime are due to seasonal variations of meteorological parameters and cyclic changes of precursors (SO2 and NO2). Stepwise Multiple Linear Regression (MLR) analysis indicates that relative humidity is the main factor influencing on meteorological parameter. Entry MLR analysis suggests that SO2 from local coal-burning power plants is still the primary pollutant. Trajectory cluster results of PM2.5 at BRR indicate that the entrained urban pollutants carried by the westerly or winter monsoon forms the dominant regional pollution sources in winter and spring. Ultraviolet (UV) aerosol index verified the source and pathway of dust storm in spring.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-15-2227-2015", "year": 2015, "title": "Identifying fire plumes in the Arctic with tropospheric FTIR measurements and transport models", "abstract": "Abstract. We investigate Arctic tropospheric composition using ground-based Fourier transform infrared (FTIR) solar absorption spectra, recorded at the Polar Environment Atmospheric Research Laboratory (PEARL, Eureka, Nunavut, Canada, 8005' N, 8642' W) and at Thule (Greenland, 7653' N, 6874' W) from 2008 to 2012. The target species, carbon monoxide (CO), hydrogen cyanide (HCN), ethane (C2H6), acetylene (C2H2), formic acid (HCOOH), and formaldehyde (H2CO) are emitted by biomass burning and can be transported from mid-latitudes to the Arctic. By detecting simultaneous enhancements of three biomass burning tracers (HCN, CO, and C2H6), ten and eight fire events are identified at Eureka and Thule, respectively, within the 5-year FTIR time series. Analyses of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model back-trajectories coupled with Moderate Resolution Imaging Spectroradiometer (MODIS) fire hotspot data, Stochastic Time-Inverted Lagrangian Transport (STILT) model footprints, and Ozone Monitoring Instrument (OMI) UV aerosol index maps, are used to attribute burning source regions and travel time durations of the plumes. By taking into account the effect of aging of the smoke plumes, measured FTIR enhancement ratios were corrected to obtain emission ratios and equivalent emission factors. The means of emission factors for extratropical forest estimated with the two FTIR data sets are 0.40 0.21 g kg1 for HCN, 1.24 0.71 g kg1 for C2H6, 0.34 0.21 g kg1 for C2H2, and 2.92 1.30 g kg1 for HCOOH. The emission factor for CH3OH estimated at Eureka is 3.44 1.68 g kg1. To improve our knowledge concerning the dynamical and chemical processes associated with Arctic pollution from fires, the two sets of FTIR measurements were compared to the Model for OZone And Related chemical Tracers, version 4 (MOZART-4). Seasonal cycles and day-to-day variabilities were compared to assess the ability of the model to reproduce emissions from fires and their transport. Good agreement in winter confirms that transport is well implemented in the model. For C2H6, however, the lower wintertime concentration estimated by the model as compared to the FTIR observations highlights an underestimation of its emission. Results show that modeled and measured total columns are correlated (linear correlation coefficient r > 0.6 for all gases except for H2CO at Eureka and HCOOH at Thule), but suggest a general underestimation of the concentrations in the model for all seven tropospheric species in the high Arctic.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JMARSYS.2010.05.006", "year": 2010, "title": "Winter phytoplankton bloom induced by subsurface upwelling and mixed layer entrainment southwest of Luzon Strait", "abstract": "Phytoplankton blooms appear in winter (NovJan) in the southwest of Luzon Strait, South China Sea, which is an oligotrophic region in general. To understand dynamic features of the winter phytoplankton bloom southwest of Luzon Strait, this study analyzes seven years (20002006) of remote sensing data of Chlorophyll a, sea surface temperature, and ocean vector winds, along with in situ observations of dissolved oxygen, nutrients (nitrate, phosphate, and silicate), and physical oceanographic parameters mixed layer depth, Ekman pumping velocity, and entrainment velocity. The results demonstrate that the winter phytoplankton bloom in the southwest of Luzon Strait is primarily induced by both Ekman pumping-driven upwelling (observed at about 50m under sea surface) and upper mixed layer entrainment. The area of winter phytoplankton blooms is about 2.58104km2, based on Empirical Orthogonal Function analysis. The seasonal variability of the bloom is associated with monsoonal wind forcing.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2010GL044629", "year": 2010, "title": "Volcanic ash fuels anomalous plankton bloom in subarctic northeast Pacific", "abstract": "Using multiple lines of evidence, we demonstrate that volcanic ash deposition in August 2008 initiated one of the largest phytoplankton blooms observed in the subarctic North Pacific. Unusually widespread transport from a volcanic eruption in the Aleutian Islands, Alaska deposited ash over much of the subarctic NE Pacific, followed by large increases in satellite chlorophyll. Surface ocean pCO2, pH, and fluorescence reveal that the bloom started a few days after ashfall. Ship-based measurements showed increased dominance by diatoms. This evidence points toward fertilization of this normally iron-limited region by ash, a relatively new mechanism proposed for iron supply to the ocean. The observations do not support other possible mechanisms. Extrapolation of the pCO2 data to the area of the bloom suggests a modest 0.01 Pg carbon export from this event, implying that even large-scale iron fertilization at an optimum time of year is not very efficient at sequestering atmospheric CO2.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2009JD013715", "year": 2010, "title": "Variations in surface ozone at Nainital: A high-altitude site in the central Himalayas", "abstract": "Surface ozone measurements have been made for the first time at Nainital (29.37N, 79.45E, 1958 m amsl), a high-altitude site in the central Himalayas, between October 2006 and December 2008. Diurnal variations in ozone do not show the daytime photochemical build-up typical of urban or rural sites. The seasonal variation shows a distinct ozone maximum in late spring (May; 67.2 14.2 ppbv) with values sometimes exceeding 100 ppbv and a minimum in the summer/monsoon season (August; 24.9 8.4 ppbv). Springtime ozone values in the central Himalayas are significantly higher than those at another high-altitude site (Mt. Abu) in the western part of India. Seasonal variations in ozone and the processes responsible for the springtime peak are studied using meteorological parameters, insolation, spatial and temporal classifications of air mass trajectories, fire counts, and simulations with a chemical transport model. Net ozone production over the Northern Indian Subcontinent in regionally polluted air masses is estimated to be 3.2 ppbv/day in spring but no clear build-up is seen at other times of year. Annual average ozone values in regionally polluted air masses (47.1 16.7 ppbv) and on high insolation days (46.8 17.3 ppbv) are similar. Background ozone levels are estimated to be 3035 ppbv. Regional pollution is shown to have maximum contribution (16.5 ppbv) to ozone levels during MayJune and is about 7 ppbv on an annual basis, while the contribution of long-range transport is greatest during JanuaryMarch (811 ppbv). The modeled stratospheric ozone contribution is 216 ppbv. Both the trajectory analysis and the model suggest that the stratospheric contribution is 46 ppbv greater than the contribution from regional pollution. Differences in the seasonal variation of ozone over high-altitude sites in the central Himalayas (Nainital) and western India (Mt. Abu) suggest diverse regional emission sources in India and highlight the large spatial and temporal variability in ozone over the Indian region.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-10-6537-2010", "year": 2010, "title": "Tropospheric ozone variations at the Nepal Climate Observatory-Pyramid (Himalayas, 5079 m a.s.l.) and influence of deep stratospheric intrusion events", "abstract": "Abstract. The paper presents the first 2 years of continuous surface ozone (O3) observations and systematic assessment of the influence of stratospheric intrusions (SI) at the Nepal Climate Observatory at Pyramid (NCO-P; 2757' N, 8648' E), located in the southern Himalayas at 5079 m a.s.l.. Continuous O3 monitoring has been carried out at this GAW-WMO station in the framework of the Ev-K2-CNR SHARE and UNEP ABC projects since March 2006. Over the period March 2006February 2008, an average O3 value of 4912 ppbv (1) was recorded, with a large annual cycle characterized by a maximum during the pre-monsoon (619 ppbv) and a minimum during the monsoon (3910 ppbv). In general, the average O3 diurnal cycles had different shapes in the different seasons, suggesting an important interaction between the synoptic-scale circulation and the local mountain wind regime. Short-term O3 behaviour in the middle/lower troposphere (e.g. at the altitude level of NCO-P) can be significantly affected by deep SI which, representing one of the most important natural input for tropospheric O3, can also influence the regional atmosphere radiative forcing. To identify days possibly influenced by SI at the NCO-P, a specially designed statistical methodology was applied to the time series of observed and modelled stratospheric tracers. On this basis, during the 2-year investigation, 14.1% of analysed days were found to be affected by SI. The SI frequency showed a clear seasonal cycle, with minimum during the summer monsoon (1.2%) and higher values during the rest of the year (21.5%). As suggested by back-trajectory analysis, the position of the subtropical jet stream could play an important role in determining the occurrence of deep SI transport on the southern Himalayas. We estimated the fraction of O3 due to SI at the NCO-P. This analysis led to the conclusion that during SI O3 significantly increased by 27.1% (+13 ppbv) with respect to periods not affected by such events. Moreover, the integral contribution of SI (O3S) to O3 at the NCO-P was also calculated, showing that up to 13.7% of O3 recorded at the measurement site could be possibly attributed to SI. On a seasonal basis, the lowest SI contributions were found during the summer monsoon (less than 0.1%), while the highest were found during the winter period (up to 24.2%). Even considering the rather large uncertainty associated with these estimates, the obtained results indicated that, during non-monsoon periods, high O3 levels could affect NCO-P during SI, thus influencing the variability of tropospheric O3 over the southern Himalayas.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/J.1752-1688.2010.00448.X", "year": 2010, "title": "Tracking Cholera in Coastal Regions Using Satellite Observations1", "abstract": "Jutla, Antarpreet S., Ali S. Akanda, and Shafiqul Islam, 2010. Tracking Cholera in Coastal Regions Using Satellite Observations. Journal of the American Water Resources Association (JAWRA) 46(4): 651-662. DOI: 10.1111/j.1752-1688.2010.00448.x Abstract: Cholera remains a significant health threat across the globe. The pattern and magnitude of the seven global pandemics suggest that cholera outbreaks primarily originate in coastal regions and then spread inland through secondary means. Cholera bacteria show strong association with plankton abundance in coastal ecosystems. This review study investigates the relationship(s) between cholera incidence and coastal processes and explores utility of using remote sensing data to track coastal plankton blooms, using chlorophyll as a surrogate variable for plankton abundance, and subsequent cholera outbreaks. Most studies over the last several decades have primarily focused on the microbiological and epidemiological understanding of cholera outbreaks. Accurate identification and mechanistic understanding of large scale climatic, geophysical, and oceanic processes governing cholera-chlorophyll relationship is important for developing cholera prediction models. Development of a holistic understanding of these processes requires long and reliable chlorophyll datasets, which are beginning to be available through satellites. We have presented a schematic pathway and a modeling framework that relate cholera with various hydroclimatic and oceanic variables for understanding disease dynamics using the latest advances in remote sensing. Satellite data, with its unprecedented spatial and temporal coverage, have potentials to monitor coastal processes and track cholera outbreaks in endemic regions.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1186/1475-2875-9-125", "year": 2010, "title": "Towards malaria risk prediction in Afghanistan using remote sensing", "abstract": "Malaria is a significant public health concern in Afghanistan. Currently, approximately 60% of the population, or nearly 14 million people, live in a malaria-endemic area. Afghanistan's diverse landscape and terrain contributes to the heterogeneous malaria prevalence across the country. Understanding the role of environmental variables on malaria transmission can further the effort for malaria control programme.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.EPSL.2009.12.030", "year": 2010, "title": "Timescales of lateral sediment transport in the Panama Basin as revealed by radiocarbon ages of alkenones, total organic carbon and foraminifera", "abstract": "Paired radiocarbon measurements on haptophyte biomarkers (alkenones) and on co-occurring tests of planktic foraminifera (Neogloboquadrina dutertrei and Globogerinoides sacculifer) from late glacial to Holocene sediments at core locations ME0005-24JC, Y69-71P, and MC16 from the south-western and central Panama Basin indicate no significant addition of pre-aged alkenones by lateral advection. The strong temporal correspondence between alkenones, foraminifera and total organic carbon (TOC) also implies negligible contributions of aged terrigenous material. Considering controversial evidence for sediment redistribution in previous studies of these sites, our data imply that the laterally supplied material cannot stem from remobilization of substantially aged sediments. Transport, if any, requires syn-depositional nepheloid layer transport and redistribution of low-density or fine-grained components within decades of particle formation. Such rapid and local transport minimizes the potential for temporal decoupling of proxies residing in different grain-size fractions and thus facilitates comparison of various proxies for paleoceanographic reconstructions in this study area. Anomalously old foraminiferal tests from a glacial depth interval of core Y69-71P may result from episodic spillover of fast bottom currents across the Carnegie Ridge transporting foraminiferal sands towards the north.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/978-90-481-9121-5_1", "year": 2010, "title": "The Ocean-Sea Ice-Atmosphere System of the Hudson Bay Complex", "abstract": "Arctic marine water, vast inputs of fresh water, nearly complete seasonal ice cover, and dynamic coastal morphology make the Hudson Bay (HB) complex remarkable among the worlds large marine areas (LMEs). Each of these features is influenced by the climate. Together they enable Foxe Basin, Hudson Strait, Ungava Bay, Hudson Bay and James Bay which comprise the HB complex, to support a well developed Arctic marine food web far south of its normal range. The life history characteristics that enable biota to thrive in the region also make them sensitive and vulnerable to changes in the seasonal ice cover, freshwater inputs, and/or water levels that can stem from changes in climate.This introductory chapter summarizes current understanding of the physical, chemical, and biological conditions in the HB complex. It also provides examples of how some of the key climate-sensitive oceanographic parameters influence species ecology. The level of research effort in this region has been low relative to the Atlantic and Pacific coasts of Canada. This limits understanding and modeling of many key processes, particularly with respect to seasonal and inter-annual change. It also limits the differentiation of natural cyclical changes from those that are anthropogenically-driven and systematic. Over the coming decades, long-term, stable research will be required to better predict and mitigate the impacts of climate change, a growing human population, hydroelectric and non-renewable resource developments, shipping, and the long range transport of contaminants on this fascinating and potentially vulnerable ecosystem.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.POCEAN.2010.03.002", "year": 2010, "title": "The influence of mixing on primary productivity: A unique application of classical critical depth theory", "abstract": "Mixing and primary productivity was examined in upwelling influenced nearshore waters off south western Eyre Peninsula (SWEP) in the eastern Great Australian Bight (EGAB), the economically and ecologically important shelf region off southern Australia that forms part of the Southern and Indian oceans. Mixing/stratification in the region was highly temporally variable with a unique upwelling circulation in summer/autumn (NovemberApril), and downwelling through winter/spring (MaySeptember). Highest productivity was associated with upwelled/stratified water (up to 2958mgCm2d1), with low productivity during periods of downwelling and mixing (300550mgCm2d1), yet no major variations in macro-nutrient concentrations were detected between upwelling and downwelling events (silica>1molL1, nitrate/nitrite>0.4molL1, phosphate>0.1molL1). We hypothesise that upwelling enriches the region with micro-nutrients. High productivity off SWEP appears to be driven by a shallowing of mixed layer depth due to the injection of upwelled waters above Zcr. Low productivity follows the suppression of enrichment during downwelling/mixing events, and is exacerbated in winter/spring by low irradiances and short daylengths.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/QJ.430", "year": 2010, "title": "The impact of soil moisture modifications on CBL characteristics in West Africa: A case-study from the AMMA campaign", "abstract": "Within the framework of the AMMA campaign in 2006, the response of surface properties to precipitation and their effect on the state of the convective boundary layer (CBL) and on convective instability were analysed. The observation periods covered the pre-monsoon onset (SOP 1) and the mature monsoon phase (SOP 2) and were performed in southwest Burkina Faso. Precipitation caused a distinctive increase in the volumetric soil moisture content in the upper 20 cm of the soil. Coupled with the increase in soil moisture, a continuous decrease of surface and soil temperature with time was observed. Changes in surface temperature, albedo, and a higher availability of water affected the partitioning of the energy balance. Highest values of the Bowen ratio were found during SOP 1 when the surface was dry and vegetation sparse. In SOP 2, a higher vegetation cover made the albedo and Bowen ratio less sensitive to changes in soil moisture. Modifications of surface fluxes influenced the CBL conditions. The CBL height in SOP 1 was 1658 m and in SOP 2 877 m. The heat budget of the CBL was dominated by sensible heat flux convergence, whereas the moisture budget was controlled by both advection and latent heat flux convergence. It was confirmed by the measurements that the diurnal development of convective instability was dominated by the CBL evolution and controlled by changes in the mid- or upper troposphere to a minor degree only. Linear correlations were found between the near-surface equivalent potential temperature and both convective available potential energy and convection index. Copyright 2009 Royal Meteorological Society", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/QJ.599", "year": 2010, "title": "The impact of mesoscale convective systems on the surface and boundary-layer structure in West Africa: Case-studies from the AMMA campaign 2006", "abstract": "Within the framework of the AMMA project, atmospheric, surface and soil observations were performed during the pre-onset phase of the monsoon (Special Observing Period SOP 1) and during the summer monsoon (SOP 2) in 2006. Based on several case-studies the paper investigates the impact of mesoscale convective systems (MCSs) on the surface and boundary layer (PBL), the recovery time of the surface and the PBL after MCS passages, and the differences between the two monsoon phases. In the pre-MCS environment the mean conditional and convective instabilities were higher in SOP 1 than in SOP 2 (e.g. CAPE = 1815 J kg1 and CAPE = 1295 J kg1, respectively). In both monsoon phases these instabilities, which were strongly reduced by MCSs, recovered within less than 2 days. Precipitation of the MCSs and the resulting soil moisture increase caused a significant decrease in the surface temperature by up to 10 K and an increase in evapotranspiration by up to 2.5 mm d1. In both phases of the monsoon, these surface anomalies and, hence, the conditions favourable for triggering MCSs by thermally induced circulation systems, diminished largely within 2 to 3 days. Due to the repeated passage of the first MCSs at intervals of a few days during SOP 1, the surface properties exhibited trends towards higher soil moisture, evapotranspiration and humidity, and lower albedo, temperature and Bowen ratio. After two weeks only, the mean conditions present in the summer monsoon were reached. In SOP 2 no significant trends could be detected. Copyright 2010 Royal Meteorological Society", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.MARPOLBUL.2009.10.017", "year": 2010, "title": "The Gulf: A young sea in decline", "abstract": "This review examines the substantial changes that have taken place in marine habitats and resources of the Gulf over the past decade. The habitats are especially interesting because of the naturally high levels of temperature and salinity stress they experience, which is important in a changing world climate. However, the extent of all natural habitats is changing and their condition deteriorating because of the rapid development of the region and, in some cases from severe, episodic warming episodes. Major impacts come from numerous industrial, infrastructure-based, and residential and tourism development activities, which together combine, synergistically in some cases, to cause the observed deterioration in most benthic habitats. Substantial sea bottom dredging for material and its deposition in shallow water to extend land or to form a basis for huge developments, directly removes large areas of shallow, productive habitat, though in some cases the most important effect is the accompanying sedimentation or changes to water flows and conditions. The large scale of the activities compared to the relatively shallow and small size of the water body is a particularly important issue. Important from the perspective of controlling damaging effects is the limited cross-border collaboration and even intra-country collaboration among government agencies and large projects. Along with the accumulative nature of impacts that occur, even where each project receives environmental assessment or attention, each is treated more or less alone, rarely in combination. However, their combination in such a small, biologically interacting sea exacerbates the overall deterioration. Very few similar areas exist which face such a high concentration of disturbance, and the prognosis for the Gulf continuing to provide abundant natural resources is poor.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1080/01431160903283868", "year": 2010, "title": "The combined use of satellite data, air-mass trajectories and model applications for monitoring dust transport over Athens, Greece", "abstract": "This study focused on Saharan dust (SD) events over Athens, Greece, based on measurements of the daily aerosol optical depth at 550 nm (AOD550) and the fine-mode fraction (FM) derived from Terra Moderate Resolution Imaging Spectroradiometer (MODIS) observations. Back-trajectories ending at Athens at altitudes of 500, 1000 and 4000 m were calculated by means of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Several criteria were taken into account to identify the SD events. According to these criteria and the altitudes of the air masses, three dust transport mechanisms were identified: (1) vertical transport (VT), including the whole atmospheric column, (2) upper atmosphere transport (UAT), above the atmospheric boundary layer, and (3) boundary layer transport (BLT), only within the lower atmospheric levels. The Aerosol Index (AI) derived from Total Ozone Mapping Spectrometer (TOMS) data was found to be adequate for characterization of the dust load over Athens, while higher values of the AI were found in cases where the dust was transported in the upper atmosphere. The predictions of the Dust Regional Atmospheric Model (DREAM) were consistent with the satellite observations and back trajectories, indicating the suitability of the model for monitoring dust transport over the Mediterranean. The analysis presents three case studies, one for each transport mechanism, where the aerosol field deduced from satellites and models is presented over the Eastern Mediterranean. In conclusion, this study shows that the combination of remote sensing measurements and back-trajectory calculations constitutes a powerful tool for the identification of SD events over Athens, while modelling can monitor the spread of the dust.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/BG-7-2091-2010", "year": 2010, "title": "The Arabian Sea as a high-nutrient, low-chlorophyll region during the late Southwest Monsoon", "abstract": "Abstract. Extensive observations were made during the late Southwest Monsoon of 2004 over the Indian and Omani shelves, and along a transect that extended from the southern coast of Oman to the central west coast of India, tracking the southern leg of the US JGOFS expedition (19941995) in the west. The data are used, in conjunction with satellite-derived data, to investigate long-term trends in chlorophyll and sea surface temperature, indicators of upwelling intensity, and to understand factors that control primary production (PP) in the Arabian Sea, focussing on the role of iron. Our results do not support an intensification of upwelling in the western Arabian Sea, reported to have been caused by the decline in the winter/spring Eurasian snow cover since 1997. We also noticed, for the first time, an unexpected development of high-nutrient, low-chlorophyll condition off the southern Omani coast. This feature, coupled with other characteristics of the system, such as a narrow shelf and relatively low iron concentrations in surface waters, suggest a close similarity between the Omani upwelling system and the Peruvian and California upwelling systems, where PP is limited by iron. Iron limitation of PP may complicate simple relationship between upwelling and PP assumed by previous workers, and contribute to the anomalous offshore occurrence of the most severe oxygen (O2) depletion in the region. Over the much wider Indian shelf, which experiences large-scale bottom water O2-depletion in summer, adequate iron supply from reducing bottom-waters and sediments seems to support moderately high PP; however, such production is restricted to the thin, oxygenated surface layer, probably because of the unsuitability of the O2-depleted environment for the growth of oxygenic photosynthesizers.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JMARSYS.2009.02.010", "year": 2010, "title": "Surface transport detected by pairs of COSMO-SkyMed ScanSAR images in the Qingdao region (Yellow Sea) during a macro-algal bloom in July 2008", "abstract": "In early summer 2008 an extended macro-algal bloom in the Qingdao coastal area caused the presence of huge algal aggregates at the sea surface clearly visible in SAR images. The event was observed by WideRegion ScanSAR data (X-band) acquired in July 2008 by the two currently operative COSMO-SkyMed satellites. The current constellation (two of four satellites operative by 2010) provides pairs of overlapping images with a time shift of 48 min, with a repeat time from 12 to 24 h. The full constellation will allow a peak daily acquisition capability of 24 min in the ScanSAR mode. The double acquisition with a short time lag, similar to a time derivative in the overlapping area, allows an accurate feature tracking and automated extraction of the surface transport not previously available. Considering that SAR images are unaffected by cloud cover, accurate surface transport patterns greatly improve the forecasting capability in the case of marine environmental emergencies.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1109/TGRS.2010.2050893", "year": 2010, "title": "Study of Data-Merging and Interpolation Methods for Use in an Interactive Online Analysis System: MODIS Terra and Aqua Daily Aerosol Case", "abstract": "Data merging with interpolation is a method of combining near-coincident satellite observations to provide complete global or regional maps for comparison with models and ground station observations. We investigate various methods and limitations of data merging (or data fusion), with and without interpolation, as a first step toward merging data sets archived in the National Aeronautics and Space Administration Goddard Earth Sciences Data and Information Services Center and made public through the Goddard Interactive Online Visualization and ANalysis Infrastructure (Giovanni) data portals. As a prototype for the data-merging algorithm, this paper uses daily global observations of aerosol optical thickness (AOT), as measured by the MODerate resolution Imaging Spectroradiometer onboard the Terra and Aqua satellites. The goal is to develop a very fast and accurate online method of data merging for implementation into Giovanni. We demonstrate three different methods for pure merging (without interpolation): simple arithmetic averaging (SAA), maximum likelihood estimate (MLE), and weighting by pixel counts. All three methods are roughly comparable, with the MLE (SAA) being slightly preferable when validating with respect to the AOT standard deviations (AOT means). To evaluate the merged product, we introduce two confidence functions, which characterize the percentage of the merged AOT pixels as a function of the relative deviation of the merged AOT from the initial Terra and Aqua AOTs. Eight combinations of merging-interpolation are applied to scenes with regular and irregular data gap patterns. Our results show that the merging-interpolation procedure can produce complete spatial fields with acceptable errors.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-10-10923-2010", "year": 2010, "title": "Sources of light-absorbing aerosol in arctic snow and their seasonal variation", "abstract": "Abstract. Two data sets consisting of measurements of light absorbing aerosols (LAA) in arctic snow together with suites of other corresponding chemical constituents are presented; the first from Siberia, Greenland and near the North Pole obtained in 2008, and the second from the Canadian arctic obtained in 2009. A preliminary differentiation of the LAA into black carbon (BC) and non-BC LAA is done. Source attribution of the light absorbing aerosols was done using a positive matrix factorization (PMF) model. Four sources were found for each data set (crop and grass burning, boreal biomass burning, pollution and marine). For both data sets, the crops and grass biomass burning was the main source of both LAA species, suggesting the non-BC LAA was brown carbon. Depth profiles at most of the sites allowed assessment of the seasonal variation in the source strengths. The biomass burning sources dominated in the spring but pollution played a more significant (though rarely dominant) role in the fall, winter and, for Greenland, summer. The PMF analysis is consistent with trajectory analysis and satellite fire maps.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-10-977-2010", "year": 2010, "title": "Source attribution and interannual variability of Arctic pollution in spring constrained by aircraft (ARCTAS, ARCPAC) and satellite (AIRS) observations of carbon monoxide", "abstract": "Abstract. We use aircraft observations of carbon monoxide (CO) from the NASA ARCTAS and NOAA ARCPAC campaigns in April 2008 together with multiyear (20032008) CO satellite data from the AIRS instrument and a global chemical transport model (GEOS-Chem) to better understand the sources, transport, and interannual variability of pollution in the Arctic in spring. Model simulation of the aircraft data gives best estimates of CO emissions in April 2008 of 26 Tg month1 for Asian anthropogenic, 9.4 for European anthropogenic, 4.1 for North American anthropogenic, 15 for Russian biomass burning (anomalously large that year), and 23 for Southeast Asian biomass burning. We find that Asian anthropogenic emissions are the dominant source of Arctic CO pollution everywhere except in surface air where European anthropogenic emissions are of similar importance. Russian biomass burning makes little contribution to mean CO (reflecting the long CO lifetime) but makes a large contribution to CO variability in the form of combustion plumes. Analysis of two pollution events sampled by the aircraft demonstrates that AIRS can successfully observe pollution transport to the Arctic in the mid-troposphere. The 20032008 record of CO from AIRS shows that interannual variability averaged over the Arctic cap is very small. AIRS CO columns over Alaska are highly correlated with the Ocean Nino Index, suggesting a link between El Nino and Asian pollution transport to the Arctic. AIRS shows lower-than-average CO columns over Alaska during April 2008, despite the Russian fires, due to a weakened Aleutian Low hindering transport from Asia and associated with the moderate 20072008 La Nina. This suggests that Asian pollution influence over the Arctic may be particularly large under strong El Nino conditions.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.DSR.2009.10.005", "year": 2010, "title": "Seasonal variation of diel vertical migration of zooplankton from ADCP backscatter time series data in the Lazarev Sea, Antarctica", "abstract": "Ten-month time series of mean volume backscattering strength (MVBS) and vertical velocity obtained from three moored acoustic Doppler current profilers (ADCPs) deployed from February until December 2005 at 64S, 66.5S and 69S along the Greenwich Meridian were used to analyse the diel vertical zooplankton migration (DVM) and its seasonality and regional variability in the Lazarev Sea. The estimated MVBS exhibited distinct patterns of DVM at all three mooring sites. Between February and October, the timing of the DVM and the residence time of zooplankton at depth were clearly governed by the daynight rhythm. Mean daily cycles of the ADCP-derived vertical velocity were calculated for successive months and showed maximum ascent and descent velocities of 16 and 15mms1. However, a change of the MVBS pattern occurred in late spring/early austral summer (October/November), when the zooplankton communities ceased their synchronous vertical migration at all three mooring sites. Elevated MVBS values were then concentrated in the uppermost layers (<50m) at 66.5S. This period coincided with the decay of sea ice coverage at 64S and 66.5S between early November and mid-December. Elevated chlorophyll concentrations, which were measured at the end of the deployment, extended from 67S to 65S and indicated a phytoplankton bloom in the upper 50m. Thus, we propose that the increased food supply associated with an ice edge bloom caused the zooplankton communities to cease their DVM in favour of feeding.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/J.1529-8817.2009.00799.X", "year": 2010, "title": "Seasonal Variability of the Organic-Walled Dinoflagellate Cyst Production in the Coastal Upwelling Region Off Cape Blanc (mauritania): A Five-Year Survey1", "abstract": "A 5-year sediment trap survey in the upwelling area off Cape Blanc (NW Africa) provides information on the seasonal and annual resting cyst production of dinoflagellates, their sinking characteristics and preservation potential. Strong annual variation in cyst production characterizes the region. Cyst production of generally all investigated species, including Alexandrium pseudogonyaulax (Biecheler) T. Horig. ex T. Kita et Fukuyo (cyst genus Impagidinium) and Gonyaulax spinifera (Clap. et J. Lachm.) Diesing (cyst genus Nematosphaeropsis) was enhanced with increasing upper water nutrient and trace-element concentrations. Cyst production of Lingulodinium polyedrum (F. Stein) J. D. Dodge was the highest at the transition between upwelling and upwelling-relaxation. Cyst production of Protoperidinium americanum (Gran et Braarud) Balech, Protoperidinium monospinum (Paulsen) K. A. F. Zonn. et B. Dale, and Protoperidinium stellatum (D. Wall) Balech, and heterotrophic dinoflagellates forming Brigantedinium spp. and Echinidinium aculeatum Zonn., increased most pronouncedly during upwelling episodes. Production of Protoperidinium conicum (Gran) Balech and Protoperidinium pentagonum (Gran) Balech cysts and total diatom valves were related, providing evidence of a predatorprey relationship. The export cyst-flux of E. aculeatum, P. americanum, P. monospinum, and P. stellatum was strongly linked to the flux of total diatom valves and CaCO3, whereas the export production of Echinidinium granulatum Zonn. and Protoperidinium subinerme (Paulsen) A. R. Loebl. correlated with total organic carbon, suggesting potential consumption of diatoms, prymnesiophytes, and organic matter, respectively. Sinking velocities were at least 274 m d1, which is in range of the diatom- and coccolith-based phytoplankton aggregates and slower fecal pellets. Species-selective degradation did not occur in the water column, but on the ocean floor.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.MARMICRO.2010.07.003", "year": 2010, "title": "Seasonal to interannual variability and geographic distribution of the silicoflagellate fluxes in the Western Mediterranean", "abstract": "A total of 337 samples collected from five sediment traps located in the Gulf of Lions, Catalan margin and the Alboran Sea have been analyzed in order to study the seasonal, interannual and geographical distributions of silicoflagellate fluxes in the Western Mediterranean. As a general trend, maximum fluxes of silicoflagellate skeletons always occurred during the spring bloom; i.e. during the winterspring transition, while minimum fluxes were recorded during summer, characterised by a strong stratification and oligotrophic conditions. However, the sediment trap record of the Catalan margin did not exhibit any clear seasonal signal, probably owing to the fertilizing effect of the rivers Llobregat and Besos. Regarding interannual variability, no clear relationship between the NAO (North Atlantic Oscillation) and the silicoflagellate fluxes was found. In contrast, the silicoflagellate assemblages from the Alboran Sea and the Gulf of Lions responded with low fluxes and a delay in their annual maximum to the anomalous conditions elicited by the 199798 El Nino Event. Furthermore, the 2003 summer heat wave over the Western Mediterranean had similar repercussions on the silicoflagellate spring maximum 2004 in the Gulf of Lions. Three silicoflagellate species were identified in the samples, following the taxonomic concepts of Throndsen (1997): Dictyocha fibula (Ehrenberg), Dictyocha speculum (Ehrenberg) and Octactis octonaria (Ehrenberg) Hovasse 1946. D. fibula was cosmopolitan and the dominant species at all sites, always accounting for more than 80%. Moreover, its maximum fluxes were recorded in those sampling sites which were under the influence of high nutrient concentrations caused by the river input. D. speculum was only recorded in the northern locations, which suggests an affinity for colder water masses. In contrast, O. octonaria was restricted to the Alboran Sea stations, where temperatures reached the highest values and nutrients were scarcer.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/QJ.475", "year": 2010, "title": "Seasonal evolution of boundary-layer turbulence measured by aircraft during the AMMA 2006 Special Observation Period", "abstract": "During the African Monsoon Multidisciplinary Analysis (AMMA) field campaign, the ATR research aircraft made observations of fluxes and thermodynamics during three 15-day periods, which allowed the seasonal evolution of the atmospheric boundary-layer (ABL) characteristics to be monitored before and after the monsoon onset. As expected, temperature and humidity showed a contrast between dry warm conditions and moister cooler conditions from one period to the other. Most of the time, the wind blew from the west (northwesterly to southwesterly) in the ABL and from the east in the free troposphere. Following rainfall events occuring in July and August, surface sensible heat flux decreased and evaporation increased while the momentum flux remained large in the entire boundary layer, whatever the period. The aim of this paper is to characterize turbulence in terms of fluxes and length-scales for ABLs that exhibit particular characteristics relative to (i) entrainment at the top, (ii) wind rotation at the interface between the monsoon and the Saharan air layer and (iii) seasonal variability. In spite of the poorer accuracy of the turbulent flux estimations at the top of the ABL, the flux profiles were observed to increase or decrease linearly with altitude which enabled accurate estimates of entrainment flux ratios. It was found that the moisture flux distribution in the ABL was governed by top-down processes during the driest period and a mixture of top-down and bottom-up processes during the monsoon period. Significant differences in turbulence length-scales were also highlighted. Copyright 2009 Royal Meteorological Society", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSE.2010.04.017", "year": 2010, "title": "Seasonal dynamics and regional features of MODIS-derived land surface characteristics in dust source regions of East Asia", "abstract": "Atmospheric mineral dust is an important component of the climate system; however, representation of dust production in the climate models poses significant challenges. Satellite remote sensing has the potential to aid in determining the surface characteristics of active dust source regions that are of importance to dust emission modeling. This study uses data from the Moderate-resolution Imaging Spectroradiometer (MODIS) in conjunction with soil texture to investigate linkages of spatial distribution of surface characteristics related to dust emission, and their dynamics, at the seasonal time scale. In addition to standard MODIS land products such as surface albedo and NDVI which are strongly linked to dust emission, we introduce a roughness index (RI) and an arid soil surface index (ASSI) to aid in land surface characterization. Three regions of northwestern China known for dust emission, the Taklamakan, Badain Jaran, and Gurbantunggut Deserts, are examined for spatial and temporal changes of surface characteristics during winterspringsummer transition FebruaryJuly 2005. A new methodology is proposed by introducing regional masking derived from MODIS Band 10 surface albedo. The analysis demonstrates regional unique temporal and spatial characteristics in the 2005 seasonal transition for these areas. Seasonal modes of response are clearly present. The soil texture correlation results demonstrate that clay fraction has a consistently high negative correlation to albedo, as does vegetation. The analysis also demonstrates that RI is a dynamic characteristic changing both with season and on much shorter time scales.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JMARSYS.2010.03.003", "year": 2010, "title": "Satellite monitoring of climatic factors regulating phytoplankton variability in the Arabian (Persian) Gulf", "abstract": "Possible factors regulating phytoplankton variability in the Arabian (Persian) Gulf were analyzed on the basis of satellite observations and meteorological data (19972009), including remotely-sensed chlorophyll a concentration (CHL), sea surface temperature, wind, solar radiation, precipitation, and aerosols. Shallow waters of northwestern Gulf influenced by Shatt Al-Arab River discharge were more productive than open Gulf waters, although seasonal CHL patterns in this and other shallow regions looked unrealistic likely because the CHL signal was obscured by bottom reflection. Therefore our further analyses focused on the open Gulf waters, which show a subtropical seasonal CHL cycle with maximum in winter and minimum in springsummer. This cycle, however, was decoupled from the seasonal extremes of wind mixing. Interannual variations of CHL in the open Gulf regions were correlated with precipitation and aerosol data rather than with wind and sea surface temperature, consistent with the hypothesis of atmospheric deposition as a factor regulating phytoplankton growth. The effect of dust fertilization was likely observed in 2000 and 2008, when low precipitation and aerosol properties indicating elevated level of aeolian dust transport were followed by phytoplankton blooms.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-10-1953-2010", "year": 2010, "title": "Saharan dust infrared optical depth and altitude retrieved from AIRS: a focus over North Atlantic comparison to MODIS and CALIPSO", "abstract": "Abstract. Monthly mean infrared (10 m) dust layer aerosol optical depth (AOD) and mean altitude are simultaneously retrieved over the tropics (30 S30 N) from almost seven years of Atmospheric Infrared Sounder (AIRS) observations covering the period January 2003 to September 2009. The method developed relies on the construction of look-up-tables computed for a large selection of atmospheric situations and follows two main steps: first, determination of the observed atmospheric thermodynamic situation and, second, determination of the dust properties. A very good agreement is found between AIRS-retrieved AODs and visible optical depths from the Moderate resolution Imaging Spectroradiometer (MODIS/Aqua) during the main (summer) dust season, in particular for three regions of the tropical North Atlantic and one region of the north-western Indian Ocean. Outside this season, differences are mostly due to the sensitivity of MODIS to aerosol species other than dust and to the more specific sensitivity of AIRS to the dust coarse mode. AIRS-retrieved dust layer mean altitudes are compared to the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP/CALIPSO) aerosol mean layer altitude for the period June 2006 to June 2009. Results for a region of the north tropical Atlantic downwind of the Sahara show a good agreement between the two products (360 m). Differences observed in the peak-to-trough seasonal amplitude, smaller from AIRS, are principally attributed to the large difference in spatial sampling of the two instruments. They also come from the intrinsic limit in sensitivity of the passive infrared sounders for low altitudes. These results demonstrate the capability of high resolution infrared sounders to measure not only dust aerosol AOD but also the mean dust layer altitude.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.2983/035.029.0107", "year": 2010, "title": "Reproduction of the Cortes Geoduck Panopea globosa (Bivalvia: Hiatellidae) and Its Relationship with Temperature and Ocean Productivity", "abstract": "This article describes the timing of gametogenic development and spawning in a population of geoduck clams, Panopea globosa (Dall 1898), from the Upper Gulf of California and its relationship to temperature changes and primary productivity. Clams were collected monthly over 1 year (March 2008 to March 2009), and salinity, dissolved oxygen, and substrate type were recorded during each survey. Standard histological analyses and measurements of oocyte diameters were used to describe the timing of gametogenic development and spawning. Satellite data for temperature and chlorophyll were gathered to test a general conceptual planktonic larval development model. The results demonstrated that reproductive activity was triggered by a steep decrease in temperature 4 months prior to the peak of productivity. Thus, larval development matches favorable conditions, as predicted by Cushing's MatchMismatch Hypothesis.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1134/S1024856010020053", "year": 2010, "title": "Regression models for the estimation of carbon exchange in boreal forests", "abstract": "Based on the measurements of the carbon dioxide fluxes at a few sites of the global FLUXNET network, we developed linear regression models for the estimation of the carbon budget of boreal forests. The model estimates satisfactorily agree with the measurement data obtained in the boreal forests of Canada (Manitoba, Thompson) and Russia (Krasnoyarsk krai, Zotino). The correlation coefficient between the calculations and measurements for a coniferous forests exceeds 0.9, with the annually mean model error in the budget estimate, as compared to the experimental results, not exceeding 50 gC/m2/yr. Using satellite and ground-based meteorological data, we calculated the monthly average carbon budget of the coniferous forests of Krasnoyarsk krai in 2001. Based on the satellite classification of the vegetation cover, we plotted monthly and annually average maps of the carbon budget that reflect the spatiotemporal distribution of the CO2 uptake and emission rates. It is shown that the coniferous forests of Krasnoyarsk krai are mostly a carbon sink, uptaking as much as 300 gC/m2 throughout the growing season.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.2174/1874282301004010001", "year": 2010, "title": "Regional Model Nesting within GFS Daily Forecasts Over West Africa", "abstract": "Regional Model Nesting within GFS Daily Forecasts Over West Africa", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12237-009-9191-7", "year": 2010, "title": "Recent Trends Towards Oligotrophication of the Northern Adriatic: Evidence from Chlorophyll a Time Series", "abstract": "The results of the updated and quality-checked data base of field observations on chlorophyll a (Chl a) collected in the period 1970-2007 in the Northern Adriatic Sea are presented. From the last decade, SeaWiFS satellite information was also considered. Results demonstrate a global tendency towards Chl a reduction in the period of investigation, which is more marked in the eutrophic area under the influence of the Po River. In the rest of the basin, which presents meso-or oligotrophic characteristics, long-term changes are more difficult to detect. The long-term field dataset can be divided into two periods: the last decade characterized by the strong decrease observed in the whole northern Adriatic and the earlier period with no or slight increase. The recent substantial reduction of Chl a concentrations is confirmed all over the basin (-0.11 mg m3 year1) from satellite-derived information. Results are consistent with recently evidenced decrease in concentrations of phosphate and ammonia and point to the existence of oligotrophication in the Northern Adriatic. Results indicate forcefully that the still common perception of the Adriatic Sea as a very eutrophic basin is no longer appropriate, at least for its northern part and in recent years.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2009.11.017", "year": 2010, "title": "Profiles of the atmospheric temperature response to the Saharan dust outbreaks derived from FORMOSAT-3/COSMIC and OMI AI", "abstract": "Based on the data from the Formosa (Taiwan) Satellite (FORMOSAT)-3/Constellation Observing System for the Meteorology, Ionosphere, and Climate (COSMIC), combined with the Ozone Monitoring Instrument (OMI) aerosol index (AI) and reflectivity, this work calculates profiles of the atmospheric temperature response to Saharan dust outbreaks (SDOs), which is one component of the Saharan Air Layer (SAL) over the North Atlantic marine boundary layer. Our results show that warming of the SAL occurs below 5km, with maximum warming located at 23km altitude. The warming of the atmosphere below 5km and above the surface also shows positive correlation between the OMI AI values and the 23km maximum warming temperatures. Cooling in the upper troposphere occurs at 57km altitudes and only appears in late summer months (JulyAugust). The amount and the vertical extent of the cooling depend on the amount of the OMI AI values. These analyses seem to support the cooling hypothesis of Dunion and Marron (2008) for the atmospheric layer about the SAL: that elevated dust loading leads to enhanced warming in the SAL, which leads to more strong vertical ascent and adiabatic cooling in the upper troposphere; and more dust loading leads to more net radiative cooling in the layer above the SAL. The net cooling of the SAL in the lower troposphere appears to be limited to close to the surface. Hence, our analysis shows that temporal variation of the vertical extent of the warming and cooling of the atmosphere due to the SAL is a complex function of the time and the amount of dust loading associated with the SAL. In this work we provide a very strong observational evidence, based upon the new FS3/C constellation, of the thermal impact of Saharan dust. In particular, we demonstrate that the surface cooling consequent to high optical thickness (and corresponding to a low level about 2km heating) which was hypothesized by previous work on theoretical background, is actually very real.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/01431161.2010.487503", "year": 2010, "title": "Precursory signals using satellite and ground data associated with the Wenchuan Earthquake of 12 May 2008", "abstract": "Multi-satellite sensor and ground observation data were analysed soon after the Wenchuan Earthquake of magnitude 7.9 (according to the USGS) or 8.0 (according to Xinhua, the Chinese News Agency) that occurred on 12 May 2008. This earthquake was felt by millions of people living in a number of countries; it took 65 000 lives and made millions of people homeless, damaged small and large infrastructure, and large surface manifestations were observed on the surface. Soon after the earthquake multi-satellite sensor and ground observatory data were analysed to study changes in ground, meteorological and atmospheric parameters. A detailed analysis of these data shows pronounced anomalous changes prior to the Wenchuan Earthquake event. Analysis of Atmospheric InfraRed Sounder (AIRS) data at different pressure levels clearly shows characteristic behaviour of the air temperature and relative humidity compared to other days. Such changes are observed up to 500 hPa, with maximal change at the lower levels. Changes in the surface, atmosphere, meteorological and ionospheric parameters prior to the Wenchuan Earthquake are complementary to one another and show the existence of a strong coupling between land, atmosphere and ionosphere, associated with the Wenchuan Earthquake.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1017/S0954102010000398", "year": 2010, "title": "Potential source regions of biogenic aerosol number concentration apportioning at King George Island, Antarctic Peninsula", "abstract": "Nowadays it is well accepted that background aerosols in the boundary layer over remote oceans are of marine origin and not aged continental. Particularly in the Atlantic sector of the Southern Ocean at least four main important regions exhibit significant ocean primary productivity. They are the BellingshausenAmundsen Sea, the Weddell Sea, the southern Argentinean shelf and the southern Chilean coast. In this work, we have combined ground-based continuous atmospheric sampling of aerosol number concentration (ANC), over-sea dimethyl sulphide (DMS) measurements, chlorophyll a (chl a) concentration provided by Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite images, in situ meteorological data and monthly regional NCEP-NCAR re-analysis wind fields in order to investigate the relative contribution of each of the above regions to the apportionment of the ANC at King George Island (KGI), South Shetland Islands. Our results suggest that, at least during the period from September 1998December 1999, the southern Argentinean shelf acted as the main contributor to the ANC measured in KGI.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1155/2010/301395", "year": 2010, "title": "Ocean Emission Effects on Aerosol-Cloud Interactions: Insights from Two Case Studies", "abstract": "Two case studies are discussed that evaluate the effect of ocean emissions on aerosol-cloud interactions. A review of the first case study from the eastern Pacific Ocean shows that simultaneous aircraft and space-borne observations are valuable in detecting links between ocean biota emissions and marine aerosols, but that the effect of the former on cloud microphysics is less clear owing to interference from background anthropogenic pollution and the difficulty with field experiments in obtaining a wide range of aerosol conditions to robustly quantify ocean effects on aerosol-cloud interactions. To address these limitations, a second case was investigated using remote sensing data over the less polluted Southern Ocean region. The results indicate that cloud drop size is reduced more for a fixed increase in aerosol particles during periods of higher ocean chlorophyll A. Potential biases in the results owing to statistical issues in the data analysis are discussed.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1088/1748-9326/6/1/014001", "year": 2010, "title": "Observations of Saharan dust layer electrification", "abstract": "Electrification of atmospheric dust influences the coagulation, wet removal and fall speeds of dust particles. Alignment of dust particles can also occur in fair weather atmospheric electrical conditions if the particles are charged. However, very few electrical measurements made in elevated dust layers exist. Balloon-borne charge and particle instrumentation have been used to investigate the electrical properties of elevated Saharan dust layers. Soundings from the Cape Verde Islands, which experience frequent Saharan dust outbreaks, intercepted several dust layers. Two balloon soundings during summer 2009 detected dust particles in layers up to 4 km altitude. Simultaneous electrical measurements showed charge inside the dust layers, with a maximum measured charge density of 25 pC m 3, sufficient to influence wet removal processes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-10-9739-2010", "year": 2010, "title": "Nitrogen oxides and PAN in plumes from boreal fires during ARCTAS-B and their impact on ozone: an integrated analysis of aircraft and satellite observations", "abstract": "Abstract. We determine enhancement ratios for NOx, PAN, and other NOy species from boreal biomass burning using aircraft data obtained during the ARCTAS-B campaign and examine the impact of these emissions on tropospheric ozone in the Arctic. We find an initial emission factor for NOx of 1.06 g NO per kg dry matter (DM) burned, much lower than previous observations of boreal plumes, and also one third the value recommended for extratropical fires. Our analysis provides the first observational confirmation of rapid PAN formation in a boreal smoke plume, with 40% of the initial NOx emissions being converted to PAN in the first few hours after emission. We find little clear evidence for ozone formation in the boreal smoke plumes during ARCTAS-B in either aircraft or satellite observations, or in model simulations. Only a third of the smoke plumes observed by the NASA DC8 showed a correlation between ozone and CO, and ozone was depleted in the plumes as often as it was enhanced. Special observations from the Tropospheric Emission Spectrometer (TES) also show little evidence for enhanced ozone in boreal smoke plumes between 15 June and 15 July 2008. Of the 22 plumes observed by TES, only 4 showed ozone increasing within the smoke plumes, and even in those cases it was unclear that the increase was caused by fire emissions. Using the GEOS-Chem atmospheric chemistry model, we show that boreal fires during ARCTAS-B had little impact on the median ozone profile measured over Canada, and had little impact on ozone within the smoke plumes observed by TES.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.ASR.2010.06.025", "year": 2010, "title": "Monitoring spatio-temporal variations in aerosols and aerosolcloud interactions over Pakistan using MODIS data", "abstract": "Clouds are important elements in climatic processes and interactions between aerosols and clouds are therefore a hot topic for scientific research. Aerosols show both spatial and temporal variations, which can lead to variations in the microphysics of clouds. In this research, we have examined the spatial and temporal variations in aerosol particles over Pakistan and the impact of these variations on various optical properties of clouds, using Moderate Resolution Imaging Spectroradiometer (MODIS) data from the Terra satellite. We used the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for trajectory analysis to reveal the origins of air masses, with the aim of understanding these spatial and temporal variabilities in aerosol concentrations. We also documented seasonal variations in patterns of aerosol optical depth (AOD) over Pakistan, for which the highest values occur during the monsoon season (JuneAugust). We then analyzed the relationships between AOD and four other cloud parameters, namely water vapour (WV), cloud fraction (CF), cloud top temperature (CTT) and cloud top pressure (CTP). Regional correlation maps and time series plots for aerosol (AOD) and cloud parameters were produced to provide a better understanding of aerosolcloud interaction. The analyses showed strong positive correlations between AOD and WV for all of the eight cities investigated. The correlation between AOD and CF was positive for those cities where the air masses were predominantly humid, but negative for those cities where the air masses were relatively dry and carried a low aerosol abundance. These correlations were clearly dependent on the meteorological conditions for all of the eight cities investigated. Because of the observed AODCF relationship, the co-variation of AOD with CTP and CTT may be attributable to large-scale meteorological variations: AOD showed a positive correlation with CTP and CTT in northern regions of Pakistan and a negative correlation in southern regions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1371/JOURNAL.PONE.0009450", "year": 2010, "title": "Modeling and Predicting Seasonal Influenza Transmission in Warm Regions Using Climatological Parameters", "abstract": "Background Influenza transmission is often associated with climatic factors. As the epidemic pattern varies geographically, the roles of climatic factors may not be unique. Previous in vivo studies revealed the direct effect of winter-like humidity on air-borne influenza transmission that dominates in regions with temperate climate, while influenza in the tropics is more effectively transmitted through direct contact. Methodology/Principal Findings Using time series model, we analyzed the role of climatic factors on the epidemiology of influenza transmission in two regions characterized by warm climate: Hong Kong (China) and Maricopa County (Arizona, USA). These two regions have comparable temperature but distinctly different rainfall. Specifically we employed Autoregressive Integrated Moving Average (ARIMA) model along with climatic parameters as measured from ground stations and NASA satellites. Our studies showed that including the climatic variables as input series result in models with better performance than the univariate model where the influenza cases depend only on its past values and error signal. The best model for Hong Kong influenza was obtained when Land Surface Temperature (LST), rainfall and relative humidity were included as input series. Meanwhile for Maricopa County we found that including either maximum atmospheric pressure or mean air temperature gave the most improvement in the model performances. Conclusions/Significance Our results showed that including the environmental variables generally increases the prediction capability. Therefore, for countries without advanced influenza surveillance systems, environmental variables can be used for estimating influenza transmission at present and in the near future.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S10872-010-0024-X", "year": 2010, "title": "Mesoscale variability along the east coast of India in spring as revealed from satellite data and OGCM simulations", "abstract": "Since mesoscale features like meanders have great importance in nourishing the coastal fisheries, satellite data analyses and a numerical modeling study were carried out for the east coast of India during spring inter-monsoon time (March-May), when biological productivity is high. During this time, the East India Coastal Current (EICC) system appears as a northward flowing western boundary current of a seasonal subtropical gyre in the Bay of Bengal prior to the summer monsoon with a more intense upwelling in the coastal region. A relatively clear sky permits satellite remote sensing of Sea Surface Temperature (SST) and Chlorophyll-a (Chl-a), whose patterns were verified against geostrophic velocity in altimeter data: i.e., phytoplankton grows in colder and nutrient richer water bounded by the seaward meanders. Progression of meanders in the coastal current was revealed and compared with an eddy-resolving Ocean General Circulation Model (OGCM), which is capable of modeling wind-driven general circulation and each stage of the meander growth. The numerical solutions provided the following results, in reasonable agreement with the linear stability theory using a two-and-a-half layer quasi-geostrophic model. Baroclinic instability plays a key role for the meander growth and eddy generation, while meanders in the coastal current are initiated by isolated mesoscale rotations propagating westward. The baroclinically unstable meanders have a wavelength of 500700 km, grow in one month and propagate downstream of the coastal current at several kilometers per day. The instability is not strong enough for the meanders to detach an eddy from the western boundary current.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2010.04.003", "year": 2010, "title": "MedREM, a rainfall erosivity model for the Mediterranean region", "abstract": "This paper presents and assesses the model MedREM, in which annual-based climate and rainstorm data are used to estimate the long-term (R)Universal Soil Loss Equations and its Revisions (USLE) annual rainfall erosivity over a large region. Two known models of rainfall erosivity (named after the first author of the original paper, Torri and Yang) were also assessed and compared with the MedREM. Yang and Torri models are both based on the annual precipitation models. MedREM also takes annual maximum daily precipitation data into account, and incorporates a longitude-dependent coefficient. The test area was a large region centered on the Mediterranean basin, in which 66 weather stations were available 43 Italian and 23 out-of-Italy sites (12 countries, about 3050 latitude North, and 1050 longitude East) with multi-year data of (R)USLE annual erosivity. The three models were calibrated against (R)USLE rainfall erosivity data from 55 stations and evaluated over a validation dataset from 11 Italian stations. On the validation dataset, the MedREM estimates generally compared well with the (R)USLE data according to NushSutcliffe coefficient (0.87 against 0.76 and 0.73 with Torri and Yang model, respectively). Implications for erosivity modelling were discussed in the context of climatic features concluding that accurate estimations of site-specific annual erosivity for the Mediterranean region require process-based model with spatially-explicit parameterization.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/NGEO856", "year": 2010, "title": "Magnitude of oceanic nitrogen fixation influenced by the nutrient uptake ratio of phytoplankton", "abstract": "The ratio of nitrogen to phosphorus in phytoplankton varies greatly with taxa and growth conditions. An ecosystem model suggests that the relative abundance of fast- and slow-growing phytoplankton controls the amount of new nitrogen added to the ocean.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/J.1365-2699.2010.02273.X", "year": 2010, "title": "Long-standing environmental conditions, geographic isolation and hostsymbiont specificity influence the relative ecological dominance and genetic diversification of coral endosymbionts in the genus Symbiodinium", "abstract": "Aim This study examines the importance of geographic proximity, host life history and regional and local differences in environment (temperature and water clarity) in driving the ecological and evolutionary processes underpinning the global patterns of diversity and distribution of symbiotic dinoflagellates. By comparing and contrasting coralalgal symbioses from isolated regions with differing environmental conditions, we may assess the potential of coral communities to respond to significant changes in climate. Location Indian Ocean. Methods Community assemblages of obligate symbiotic invertebrates were sampled at numerous sites from two regions, the north-eastern Indian Ocean (Andaman Sea, western Thailand) and the western Indian Ocean (Zanzibar, Tanzania). Molecular genetic methods, including denaturing gradient gel electrophoresis analysis of the ribosomal internal transcribed spacers, DNA sequencing and microsatellite genotyping, were used to characterize the species diversity and evolutionary relationships of symbiotic dinoflagellates (genus Symbiodinium). Hostsymbiont specificity, geographic isolation and local and regional environmental factors were evaluated in terms of their importance in governing the distribution and prevalence of certain symbiont taxa. Results Host-generalist symbionts (C3u and D1-4, formerly D1a now designated Symbiodinium trenchi) frequently occurred alone and sometimes together in hosts with horizontal modes of symbiont acquisition. However, the majority of Symbiodinium diversity consisted of apparently host-specific species. Clade C Symbiodinium were diverse and dominated host assemblages from sites sampled in the western Indian Ocean, a pattern analogous to symbiont communities on the Great Barrier Reef with similar environmental conditions. Clade D Symbiodinium were diverse and occurred frequently in hosts from the north-eastern Indian Ocean, especially at inshore locations, where temperatures are warmer, water turbidity is high and large tidal exchanges commonly expose coral populations to aerial desiccation. Main conclusions Regional and local differences in cnidarianalgal combinations indicate that these symbioses are ecologically and evolutionarily responsive and can thrive under various environmental conditions. The high temperatures and turbid conditions of the north-eastern Indian Ocean partly explain the ecological success of Clade D Symbiodinium relative to Clade C. Phylogenetic, ecological and population genetic data further indicate that Clade D has undergone an adaptive radiation, especially in regions around Southeast Asia, during the Pleistocene.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.GLOPLACHA.2010.02.003", "year": 2010, "title": "Long-range transport of dust aerosols over the Arabian Sea and Indian region A case study using satellite data and ground-based measurements", "abstract": "The present study addresses an intense dust storm event over the Persian Gulf and the Arabian Sea (AS) region and its transport over the Indian subcontinent using multi-satellite observations and ground-based measurements. A time series of Indian geostationary satellite KALPANA-1 Very High Resolution Radiometer (VHRR) together with ground observations are used to analyze the temporal variation of the dust event that occurred from 19 to 24 February 2008 with the strongest intensity on 22 February. The Ozone Monitoring Instrument (OMI) Aerosol Index (AI) is also examined to provide an independent assessment of dust presence and plume location. During the dust event drastic increase in Terra/Aqua MODIS AOD550 (>1.0) and AURA-OMI-AI is observed. Vertically-resolved attenuated backscatter during daytime and nighttime from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) is also used as an additional tool to monitor the dust vertical distribution. The main dust layer is observed to be situated between 3 and 5km in altitude, while the CALIPSO observations on vertical profile of aerosols are in qualitative agreement with values of MODIS-AOD550 and OMI-AI. Ground-based measurements show significant reduction in solar irradiance on the dust-laden day (22 February 2008) over Hyderabad, while sun photometer derived AODs from six AERONET sites in south Asia verify the presence of dust and its transport from west to east.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/BG-7-3167-2010", "year": 2010, "title": "Latitudinal distribution of Trichodesmium spp. and N2 fixation in the Atlantic Ocean", "abstract": "Abstract. We have determined the latitudinal distribution of Trichodesmium spp. abundance and community N2 fixation in the Atlantic Ocean along a meridional transect from ca. 30 N to 30 S in NovemberDecember 2007 and AprilMay 2008. The observations from both cruises were highly consistent in terms of absolute magnitude and latitudinal distribution, showing a strong association between Trichodesmium abundance and community N2 fixation. The highest Trichodesmium abundances (mean = 220 trichomes L1,) and community N2 fixation rates (mean = 60 mol m2 d1) occurred in the Equatorial region between 5 S15 N. In the South Atlantic gyre, Trichodesmium abundance was very low (ca. 1 trichome L1) but N2 fixation was always measurable, averaging 3 and 10 mol m2 d1 in 2007 and 2008, respectively. We suggest that N2 fixation in the South Atlantic was sustained by other, presumably unicellular, diazotrophs. Comparing these distributions with the geographical pattern in atmospheric dust deposition points to iron supply as the main factor determining the large scale latitudinal variability of Trichodesmium spp. abundance and N2 fixation in the Atlantic Ocean. We observed a marked South to North decrease in surface phosphate concentration, which argues against a role for phosphorus availability in controlling the large scale distribution of N2 fixation. Scaling up from all our measurements (42 stations) results in conservative estimates for total N2 fixation of 6 TgN yr1 in the North Atlantic (040 N) and ~1.2 TgN yr1 in the South Atlantic (040 S).", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-10-8305-2010", "year": 2010, "title": "Joint spatial variability of aerosol, clouds and rainfall in the Himalayas from satellite data", "abstract": "Abstract. Satellite-based precipitation, Aerosol Optical Depth (AOD), Cloud Optical Depth (COD), and Aerosol Index (AI) data were used to characterize the linkages among landform and the intra-annual variability of aerosols, cloudiness and rainfall in the Himalayas using empirical orthogonal function (EOF) analysis. The first modes of AOD and AI show the presence of two branches of dust aerosol: over the Indus river basin and the Thar desert with a sharp west-east gradient parallel to the southern slopes of the Himalayas the Southern Branch; and the second against the slopes of the Tian Shan and over the Takla Makan desert in the Tibetan Plateau-the Northern branch. The third EOF mode of AOD accounts for about 7% of overall variance of AOD. It is attached to the foothills of the Himalayas east of the Aravalli range peaking in April-May-June followed by a sharp decrease in July during the first active phase of the monsoon. The first and second EOF modes of COD and precipitation show consistent patterns against the central and eastern Himalayas and along the ocean-land boundaries in western India and the Bay of Bengal. The break in cloudiness and rainfall between the winter and the monsoon seasons is captured well by the second EOF mode of COD and rainfall concurrent with the aerosol build up mode (AprilMay) over the region depicted by the third mode of AOD. The results show that the Aravalli range separates the two different modes of aerosol variability over northern India with dust aerosols to the west and polluted mixed aerosols to the east consistent with its role in regional circulation and precipitations patterns as per Barros et al. (2004) and Chiao and Barros (2007). SVD analysis between rainfall, COD and AOD showed a pattern of aerosol loading (resembling EOF3 of MODIS AOD) extending from 80 E~90 E that peaks during the winter and pre-monsoon seasons and decays abruptly during the monsoon: the regions of aerosol buildup during the pre-monsoon season and the areas of high rainfall/cloudiness during the monsoon are collocated and have opposite signs suggesting aerosol-cloud-rainfall interaction. It is proposed that the third EOF of AOD maps the area where aerosol-cloud-rainfall interactions play an important role in the regional hydro-climatology.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.DSR.2010.05.005", "year": 2010, "title": "Intra-annual variability of extremely rapid sedimentation onto Gardar Drift in the northern North Atlantic", "abstract": "North Atlantic sediment drifts are valuable archives for paleoceanographic reconstructions spanning various timescales. However, the short-term dynamics of such systems are poorly known, and this impinges on our ability to quantitatively reconstruct past change. Here we describe a high-resolution 319-day time-series of hydrodynamics and near-bottom (4m) particulate matter flux variability at a 2600m deep site with an extremely high sediment accumulation rate on the southern Gardar Drift in the North Atlantic. We compare our findings with the actual deposits at the site. The total annual particle flux amounted to 360gm2yr1, varied from 0.15 to >5.0gm2day1 and displayed strong seasonal compositional changes, with the highest proportion of fresh biogenic matter arriving after the spring bloom in June and July. Flux variability also depended on the changing input of lithogenic matter that had been (re)suspended for a longer time (decades). Active focussing of material from both sources is required to account for the composition and the magnitude of the total flux, which exceed observations elsewhere by an order of magnitude. The enhanced focussing or increased delivery appeared to be positively related to current velocity. The intercepted annual particle flux accounted for only 60% of the sediment accumulation rate of 60020gm2yr1 (0.200.07cmyr1), indicating higher intra- and inter-annual variability of both the biogenic and lithogenic fluxes and/or advection of additional sediment closer to the seafloor (i.e. <4m). This temporal variability in the composition and amount of material deposited highlights intra-annual changes in the flux of lithogenic material, but also underscores the importance of (reworked) sediment focussing and seasonality of the biogenic flux. All should be taken into account in the interpretation of the paleorecord from such depositional settings.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.MARPOLBUL.2010.06.039", "year": 2010, "title": "Inherent optical properties and satellite retrieval of chlorophyll concentration in the lagoon and open ocean waters of New Caledonia", "abstract": "The retrieval of chlorophyll-a concentration from remote sensing reflectance (Rrs) data was tested with the NASA OC4v4 algorithm on the inner New Caledonian lagoon (Case 2) and adjacent open ocean (Case 1) waters. The input to OC4v4 was Rrs measured in situ or modeled from waters inherent optical properties (20012007). At open ocean stations, backscattering and absorption coefficients were correlated with chlorophyll (R2=0.310.51, respectively), in agreement with models for Case 1 waters. Taking spectrofluorometric measurement as reference, the OC4v4 model leads to an average underestimation of 33% of the chlorophyll concentration. For the lagoon waters, OC4v4 performed inadequately because the backscattering coefficient, highly correlated with turbidity and suspended matter (R2=0.98), was poorly correlated to chlorophyll (R2=0.42). The OC4v4 performance was better in deep lagoon waters for stations with a TDT index (Tchladepth/turbidity) higher than 19mgm2 NTU1 (R2=0.974, bias=10.2%). Global Imager Rrs provided a good estimate of Tchla (R2=0.79, N=28) in the deeper part of the lagoon.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431160902882678", "year": 2010, "title": "Influence of solar proton events during the declining phase of solar cycle 23 on the total ozone concentration in India", "abstract": "Depletion of ozone under the influence of solar proton events (SPEs) is an important natural phenomenon affecting the middle mesospheric and upper stratospheric ozone content. When the Sun went through the declining phase of its activity in solar cycle 23, it unleashed a series of large eruptions, which were unusually intense flares, and accelerated particles to unprecedented energy levels. The severe impact of these events was felt in the Earth's atmosphere, not only at higher latitudes but also at the middle latitudes and tropics. The impact of nine such SPEs, having different proton flux and time duration on the total ozone content at Indian latitude belts, was studied using the ozone data obtained from Earth Probe Total Ozone Mapping Spectrometer and Ozone Monitoring Instrument. It is observed that, for high proton flux, the depletion in ozone levels extended up to low latitudes. The observed depletion in ozone was found to be higher for longer time duration of the SPE.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/978-90-481-3109-9_38", "year": 2010, "title": "Influence of a Tropical Cyclone Gonu on Phytoplankton Biomass (Chlorophyll a) in the Arabian Sea", "abstract": "Tropical cyclones could gradually affect the physical, chemical, and biological processes in the upper layer of the ocean. In terms of biological consequences, the cyclone wind field causes local mixing which results in the injection of nutrients into the upper layer of the ocean and triggering phytoplankton bloom (Subrahmanyam et al. 2002). In some cases, the magnitude of the hurricane-induced bloom could reach a gradual (30-fold) increase in the surface chlorophyll a concentration, as well as an increase in the primary production (Lin et al. 2003; Smitha et al. 2006). In the regions where cyclones often occur, their propagation could chiefly influence the annual productivity of the ocean. For example, an average of 14 cyclones pass over the South China Sea annually, which suggests the contribution of cyclones to annual production to be as much as 20-30% (Lin et al. 2003).", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1080/01431161.2010.496474", "year": 2010, "title": "Impact of satellite based PAR on estimates of terrestrial net primary productivity", "abstract": "Biospheric productivity regulates the supply of food for mankind and therefore, there is a need to estimate its magnitude. The productivity is controlled by the process of photosynthesis driven by solar radiation, primarily in the visible part of the spectrum (0.40.7 m), known as the photosynthetically active radiation (PAR). Current methods to estimate terrestrial net primary production (NPP) use remotely sensed information on vegetation dynamics. Satellite based estimates of PAR are available at a global scale but have seldom been used for estimating NPP. In this study we show that the use of PAR information from satellites does have an impact on estimates of NPP and that there are detectable differences when compared to similar estimates based on conventional PAR information. Net primary production tends to be higher when compared to estimates based on total shortwave (SW) radiation with PAR assumed to be a constant fraction of SW. We focus on the United States during 2004. Net primary production is generally underestimated in regions with mesic environment while overestimated in areas with xeric environment. The most pronounced underestimated region is the southeast United States. The study demonstrates the usefulness of the satellite-based estimates of PAR for modelling terrestrial primary productivity.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S10872-010-0028-6", "year": 2010, "title": "Impact of Alaskan Stream eddies on chlorophyll distribution in the North Pacific", "abstract": "The impact of the Alaskan Stream (AS) eddies on the chlorophyll a (chl-a) distribution in the central subarctic North Pacific was investigated through analysis of chl-a and altimetry data from satellite observations. Altimetry observations provided the locations of mesoscale eddies in time and space within the maps of chlorophyll distributions. The climatological chl-a distributions averaged in the area and time showing presence of AS eddies suggested that AS eddies contributed significantly to the chl-a distribution in the deep-sea region of the subarctic North Pacific. The chl-a distribution was closely related to the AS eddies regardless of whether the eddy was located in or detached from the AS. A combination of two or three AS eddies sometimes formed high chl-a concentration belts that injected chlorophyll and coastal nutrient-rich waters southward from the Aleutian Islands far into the deep-sea region of the subarctic North Pacific. These results indicate that chl-a distribution in the central subarctic North Pacific was strongly impacted by AS eddies.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ANGEO-28-367-2010", "year": 2010, "title": "Impact of agriculture crop residue burning on atmospheric aerosol loading a study over Punjab State, India", "abstract": "Abstract. The present study deals with the impact of agriculture crop residue burning on aerosol properties during October 2006 and 2007 over Punjab State, India using ground based measurements and multi-satellite data. Spectral aerosol optical depth (AOD) and Angstrom exponent () values exhibited larger day to day variation during crop residue burning period. The monthly mean Angstrom exponent \"\" and turbidity parameter \"\" values during October 2007 were 1.310.31 and 0.360.21, respectively. The higher values of \"\" and \"\" suggest turbid atmospheric conditions with increase in fine mode aerosols over the region during crop residue burning period. AURA-OMI derived Aerosol Index (AI) and Nitrogen dioxide (NO2) showed higher values over the study region during October 2007 compared to October 2006 suggesting enhanced atmospheric pollution associated with agriculture crop residue burning.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ECSS.2010.08.009", "year": 2010, "title": "Hot-spots of primary productivity: An Alternative interpretation to Conventional upwelling models", "abstract": "The eastern Great Australian Bight (EGAB) forms part of the Southern and Indian Oceans and is an area of high ecological and economic importance. Although it supports a commercial fishery, quantitative estimates of the primary productivity underlying this industry are open to debate. Estimates range from <100 mg C m2 day1 to > 500 mg C m2 day1. Part of this variation may be due to the unique upwelling circulation of shelf waters in summer/autumn (NovemberApril), which shares some similarities with highly productive eastern boundary current upwelling systems, but differs due to the influence of a northern boundary current, the Flinders current, and a wide continental shelf. This study examines spatial variations in primary productivity in the EGAB during the upwelling seasons of 2005 and 2006. Daily integral productivity calculated using the vertically generalised production model (VGPM) showed a high degree of spatial variation. Productivity was low (<800 mg C m2 day1) in offshore central and western regions of the EGAB. High productivities (16003900 mg C m2 day1) were restricted to hotspots in the east that were influenced by the upwelled water mass. There was a strong correlation between the depth of the euphotic zone and the depth of the mixed layer that suggested that 50% of the euphotic zone lay below the mixed layer depth. As a result, high rates of primary productivity did not require upwelled water to reach the surface. A significant proportion of total productivity in the euphotic zone (57% in 2005 and 65% in 2006) occurred in the upwelled water mass below the surface mixed layer. This result has implications for daily integral productivities modelled with the VGPM, which uses surface measures of phytoplankton biomass to calculate productivity. Macro-nutrient concentrations could not be used to explain the difference in the low and high productivities (silica > 1 mol L1, nitrate/nitrite > 0.4 mol L1, phosphate > 0.1 mol L1). Mixing patterns or micro-nutrient concentrations are possible explanations for spatial variations in primary productivity in the EGAB. On a global scale, daily rates of primary productivity of the EGAB lie between the highly productive eastern boundary current upwelling systems, and less productive coastal regions of western and south eastern Australia, and the oligotrophic ocean. However, daily productivity rates in the upwelling hotspots of the EGAB rival productivities in Benguela and Humboldt currents.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1098/RSPB.2010.0385", "year": 2010, "title": "Hostsymbiont recombination versus natural selection in the response of coraldinoflagellate symbioses to environmental disturbance", "abstract": "Mutualisms between reef-building corals and endosymbiotic dinoflagellates are particularly sensitive to environmental stress, yet the ecosystems they construct have endured major oscillations in global climate. During the winter of 2008, an extreme cold-water event occurred in the Gulf of California that bleached corals in the genus Pocillopora harbouring a thermally sensitive symbiont, designated Symbiodinium C1b-c, while colonies possessing Symbiodinium D1 were mostly unaffected. Certain bleached colonies recovered quickly while others suffered partial or complete mortality. In most colonies, no appreciable change was observed in the identity of the original symbiont, indicating that these partnerships are stable. During the initial phases of recovery, a third species of symbiont B1Aiptasia, genetically identical to that harboured by the invasive anemone, Aiptasia sp., grew opportunistically and was visible as light-yellow patches on the branch tips of several colonies. However, this symbiont did not persist and was displaced in all cases by C1b-c several months later. Colonies with D1 were abundant at inshore habitats along the continental eastern Pacific, where seasonal turbidity is high relative to offshore islands. Environmental conditions of the central and southern coasts of Mexico were not sufficient to explain the exclusivity of D1 Pocillopora in these regions. It is possible that mass mortalities associated with major thermal disturbances during the 19971998 El Nino Southern Oscillation eliminated C1b-c holobionts from these locations. The differential loss of Pocillopora holobionts in response to thermal stress suggests that natural selection on existing variation can cause rapid and significant shifts in the frequency of particular coralalgal partnerships. However, coral populations may take decades to recover following episodes of severe selection, thereby raising considerable uncertainty about the long-term viability of these communities.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-10-8119-2010", "year": 2010, "title": "Haze types in Beijing and the influence of agricultural biomass burning", "abstract": "Abstract. Emissions from agricultural biomass burning (ABB) in northern China have a significant impact on the regional and global climate. The monthly average aerosol optical depth (AOD) at 550 nm in northern China in 2007 had a maximum of 0.7 in June. The AOD measurements are consistent with regional brown hazes that occurred at that time, which was a period of severe aerosol pollution. Aerosol particles were collected in urban Beijing from 12 to 30 June 2007, during a period of high haze, and studied using transmission electron microscopy with energy-dispersive X-ray spectrometry. The dominant particle types collected in the fine fraction (diameter <1 m) were ammonium sulfate, soot, K2SO4, KNO3, and organic matter, except that the K salts were minor between 21 and 30 June. K-rich particles as tracers of biomass burning, together with wildfire maps, show that intense regional ABB in northern China contributed significantly to the regional haze between 12 and 20 June. We therefore grouped the episodes into type-1 and -2 haze, with the former occurring between 12 and 20 June and the latter between 21 and 30 June. After long-range transport, ABB particles in the type-1 haze exhibited marked changes in morphology, composition, and mixing state. KCl particles were absent, presumably having been converted by heterogeneous reactions to K2SO4 and KNO3. Soot particles were mixed with the other particle types. Abundant organic matter and soluble salts emitted by ABB increased their sizes during transport and resulted in more hygroscopic aerosol particles in downwind areas, becoming additional cloud condensation nuclei. The high AOD (average value 2.2) in Beijing during 12 to 20 June is partly explained by the hygroscopic growth of fine aerosol particles and by the strong absorption of internally mixed soot particles, both coming from regional ABB emissions. Therefore, it is important to consider the origins of the haze, which in turn leads to the different particle types.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1155/2010/939171", "year": 2010, "title": "Global Modeling of the Oceanic Source of Organic Aerosols", "abstract": "The global marine organic aerosol budget is investigated by a 3-dimensional chemistry-transport model considering recently proposed parameterisations of the primary marine organic aerosol (POA) and secondary organic aerosol (SOA) formation from the oxidation of marine volatile organic compounds. MODIS and SeaWiFS satellite data of Chlorophyll-a and ECMWF solar incoming radiation, wind speed, and temperature are driving the oceanic emissions in the model. Based on the adopted parameterisations, the SOA and the submicron POA marine sources are evaluated at about 5 Tg ( 1.5 Tg C ) and 7 to 8 Tg ( 4 Tg C ), respectively. The computed marine SOA originates from the dimethylsulfide oxidation ( 78%), the potentially formed dialkyl amine salts ( 21%), and marine hydrocarbon oxidation ( 0.1%). Comparison of calculations with observations indicates an additional marine source of soluble organic carbon that could be partially encountered by marine POA chemical ageing.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1504/IJHST.2012.047409", "year": 2012, "title": "A feasibility of six-hourly rainfall forecast over central India using model output and remote sensing data", "abstract": "Rainfall forecast has prime importance in an agrarian country like India, wherein the agricultural production is solely dependent on monsoon rainfall. In this paper, an artificial neural network (ANN) technique is used to construct a non-linear mapping between output data from global forecast system (GFS) and rainfall from tropical rainfall measuring mission (TRMM) satellite measurements. The objective of the present study is to generate region-specific six-hourly quantitative rainfall forecast over central India using ANN and resilient propagation learning algorithm. Meteorological variables from the GFS model and precipitation product from TRMM multisatellite precipitation analysis (TMPA) are used as input data for training the network, which generate rainfall forecast for the next time step. The test was performed for central India during the summer monsoon period of 2010. In order to evaluate the potential of rainfall forecast skill over the studied region, the forecast precipitation has been intercompared with TMPA-3B42, and Kalpana-1 derived precipitation products and a statistical analysis was performed. The linear correlation between ANN forecast and TMPA-3B42 rainfall was 0.58, whereas it was 0.52 with Kalpana-1 derived precipitation estimates. The results show that the predicted precipitation by the present technique performs better than GFS model precipitation forecast, and the system indicates a potential for more accurate rainfall forecasting.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.TOXICON.2010.02.026", "year": 2010, "title": "Ciguatera fish poisoning and sea surface temperatures in the Caribbean Sea and the West Indies", "abstract": "Ciguatera fish poisoning (CFP) is a circumtropical disease caused by ingestion of a variety of reef fish that bioaccumulate algal toxins. Distribution and abundance of the organisms that produce these toxins, chiefly dinoflagellates of the genus Gambierdiscus, are reported to correlate positively with water temperature. Consequently, there is growing concern that increasing temperatures associated with climate change could increase the incidence of CFP. This concern prompted experiments on the growth rates of six Gambierdiscus species at temperatures between 18C and 33C and the examination of sea surface temperatures in the Caribbean and West Indies for areas that could sustain rapid Gambierdiscus growth rates year-round. The thermal optimum for five of six Gambierdiscus species tested was 29C. Long-term SST data from the southern Gulf of Mexico indicate the number of days with sea surface temperatures 29C has nearly doubled (44 to 86) in the last three decades. To determine how the sea surface temperatures and Gambierdiscus growth data correlate with CFP incidences in the Caribbean, a literature review and a uniform, region-wide survey (19962006) of CFP cases were conducted. The highest CFP incidence rates were in the eastern Caribbean where water temperatures are warmest and least variable.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/BG-7-217-2010", "year": 2010, "title": "Flux and composition of settling particles across the continental margin of the Gulf of Lion: the role of dense shelf water cascading", "abstract": "Abstract. Settling particles were collected using sediment traps deployed along three transects in the Lacaze-Duthiers and Cap de Creus canyons and the adjacent southern open slope from October 2005 to October 2006. The settling material was analyzed to obtain total mass fluxes and main constituent contents (organic matter, opal, calcium carbonate, and siliciclastics). Cascades of dense shelf water from the continental shelf edge to the lower continental slope occurred from January to March 2006. They were traced through strong negative near-bottom temperature anomalies and increased current speeds, and generated two intense pulses of mass fluxes in January and March 2006. This oceanographic phenomenon appeared as the major physical forcing of settling particles at almost all stations, and caused both high seasonal variability in mass fluxes and important qualitative changes in settling material. Fluxes during the dense shelf water cascading (DSWC) event ranged from 90.1 g m2 d1 at the middle Cap de Creus canyon (1000 m) to 3.2 g m2 d1 at the canyon mouth (1900 m). Fractions of organic matter, opal and calcium carbonate components increased seaward, thus diminishing the siliciclastic fraction. Temporal variability of the major components was larger in the canyon mouth and open slope sites, due to the mixed impact of dense shelf water cascading processes and the pelagic biological production. Results indicate that the cascading event remobilized and homogenized large amounts of material down canyon and southwardly along the continental slope contributing to a better understanding of the off-shelf particle transport and the internal dynamics of DSWC events.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-10-10771-2010", "year": 2010, "title": "Feedback between dust particles and atmospheric processes over West Africa during dust episodes in March 2006 and June 2007", "abstract": "Abstract. We used the comprehensive model system COSMO-ART to quantify the impact of mineral dust on the radiative fluxes, the temperature and the feedback between dust particles and their emissions. We simulated two dust storms over West Africa in March 2006 and in June 2007. Simulations with and without coupling of the actual dust concentration with the radiative fluxes and the thermodynamics were carried out for each case. The model results for the 2006 case were compared with observations of the AMMA campaign. At the surface the shortwave radiative effect of mineral dust can be described by a linear relation between the changes in net surface radiation and the aerosol optical depth (AOD). For an AOD at 450 nm of 1 the average shortwave radiation reduction amounts 140 W m2 during noon. The longwave radiative effect of mineral dust is nonlinear, with an average increase of +70 W m2 for an AOD (450 nm) of 1. At the top of the atmosphere the effect of the dust layer with an AOD of 1 on radiative fluxes is not as significant as at the surface. It is slightly positive for the shortwave and approximately 26 W m2 for the longwave radiation. The height range and the extension of the dust layer determine the effect of dust particles on the 2 m temperature. When the dust layer is attached to the surface and lasts for several days it leads to an increase of the surface temperature even during daytime. In case of an elevated dust layer there is a decrease in 2 m temperature of up to 4 K during noon. It is shown, that the temperature changes caused by mineral dust may result in horizontal temperature gradients which also modify near surface winds. Since surface wind thresholds decide the uptake of dust from the surface, a feedback on total emission fluxes is established. The coupled model provides an increase in the total emission fluxes of dust particles by about 16% during the dust storm in March 2006 and 25% during the dust episode in June 2007.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-10-2129-2010", "year": 2010, "title": "Evaluation of aerosol distributions in the GISS-TOMAS global aerosol microphysics model with remote sensing observations", "abstract": "Abstract. The Aerosol Optical Depth (AOD) and Angstrom Coefficient (AC) predictions in the GISS-TOMAS model of global aerosol microphysics are evaluated against remote sensing data from MODIS, MISR, and AERONET. The model AOD agrees well (within a factor of two) over polluted continental (or high sulfate), dusty, and moderate sea-salt regions but less well over the equatorial, high sea-salt, and biomass burning regions. Underprediction of sea-salt in the equatorial region is likely due to GCM meteorology (low wind speeds and high precipitation). For the Southern Ocean, overprediction of AOD is very likely due to high sea-salt emissions and perhaps aerosol water uptake in the model. However, uncertainties in cloud screening at high latitudes make it difficult to evaluate the model AOD there with the satellite-based AOD. AOD in biomass burning regions is underpredicted, a tendency found in other global models but more severely here. Using measurements from the LBA-SMOCC 2002 campaign, the surface-level OC concentration in the model are found to be underpredicted severely during the dry season while much less severely for EC concentration, suggesting the low AOD in the model is due to underpredictions in OM mass. The potential for errors in emissions and wet deposition to contribute to this bias is discussed.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00703-010-0106-8", "year": 2010, "title": "Estimation of Indian summer monsoon rainfall using Kalpana-1 VHRR data and its validation using rain gauge and GPCP data", "abstract": "In the present study, an attempt has been made to estimate and validate the daily and monthly rainfall during the Indian summer monsoon seasons of 2008 and 2009 using INSAT (Indian National Satellite System) Multispectral Rainfall Algorithm (IMSRA) technique utilizing Kalpana-1 very high resolution radiometer (VHRR) measurements. In contrary to infrared (IR), microwave (MW) rain rates are based on measurements that sense precipitation in clouds and do not rely merely on cloud top temperature. Geostationary satellites provide broad coverage and frequent refresh measurements but microwave measurements are accurate but sparse. IMSRA technique is the combination of the infrared and microwave measurements which make use of the best features of both IR- and MW-based rainfall estimates. The development of this algorithm included two major steps: (a) classification of rain-bearing clouds using proper cloud classification scheme utilizing Kalpana-1 IR and water vapor (WV) brightness temperatures (Tb) and (b) collocation of Kalpana-1 IR brightness temperature with Tropical Rainfall Measuring Mission (TRMM)-Precipitation Radar (PR) surface rain rate and establishment of a regression relation between them. In this paper, the capability of IMSRA as an operational algorithm has been tested for the two monsoon seasons 2008 and 2009. For this, IMSRA has been used to estimate daily and monthly rainfall and has been intercompared on daily and monthly scales with TRMM Multisatellite Precipitation Analysis (TMPA)-3B42 V6 product and Global Precipitation Climatology Project (GPCP) rain product during these two monsoon years. The daily and monthly IMSRA rainfall has also been validated against ground-based observations from Automatic Weather Station (AWS) Rain Gauge and Buoy data. The algorithm proved to be in good correlation with AWS data over land up to 0.70 for daily rain estimates except orographic regions like North-East and South-West India and 0.72 for monthly rain estimates. The validation with Buoys gives the reasonable correlation of 0.49 for daily rain estimates and 0.66 for monthly rain estimates over Tropical Indian Ocean.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1155/2010/239808", "year": 2010, "title": "Effects of Ocean Ecosystem on Marine Aerosol-Cloud Interaction", "abstract": "Using satellite data for the surface ocean, aerosol optical depth (AOD), and cloud microphysical parameters, we show that statistically significant positive correlations exist between ocean ecosystem productivity, the abundance of submicron aerosols, and cloud microphysical properties over different parts of the remote oceans. The correlation coefficient for remotely sensed surface chlorophyll a concentration ([Chl-a]) and liquid cloud effective radii over productive areas of the oceans varies between and . Special attention is given to identifying (and addressing) problems from correlation analysis used in the previous studies that can lead to erroneous conclusions. A new approach (using the difference between retrieved AOD and predicted sea salt aerosol optical depth, ) is developed to explore causal links between ocean physical and biological systems and the abundance of cloud condensation nuclei (CCN) in the remote marine atmosphere. We have found that over multiple time periods, 550 nm (sensitive to accumulation mode aerosol, which is the prime contributor to CCN) correlates well with [Chl-a] over the productive waters of the Southern Ocean. Since [Chl-a] can be used as a proxy of ocean biological productivity, our analysis demonstrates the role of ocean ecology in contributing CCN, thus shaping the microphysical properties of low-level marine clouds.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.RSE.2015.05.018", "year": 2015, "title": "Global retrieval of marine and terrestrial chlorophyll fluorescence at its red peak using hyperspectral top of atmosphere radiance measurements: Feasibility study and first results", "abstract": "Chlorophyll fluorescence is directly linked to the physiology of phytoplankton or plants. Here, we present a new satellite remote sensing approach to retrieve chlorophyll fluorescence at its red peak (~685nm) by using measurements from the hyperspectral instruments SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY) and Global Ozone Monitoring Experiment-2 (GOME-2). This method, which is based on the Differential Optical Absorption Spectroscopy (DOAS) technique, was used to exploit narrow spectral structures resulting from the filling-in of the Fraunhofer Fe I line, which originates from fluorescence. The reference spectra for chlorophyll fluorescence were calculated by the coupled oceanatmosphere radiative transfer model SCIATRAN. We compared our results on marine chlorophyll fluorescence observations with the MODIS Terra normalized Fluorescence Line Height (nFLH) product for the average of years 20032011 and year 2009. Our method also enables the retrieval of chlorophyll fluorescence above land vegetation scenes. The results for the fluorescence observed above terrestrial vegetation for July and December 2009 were compared to MODIS Enhanced Vegetation Index (EVI). The comparisons show good spatial agreement between different retrievals providing evidence for the good performance of our algorithm. The method presented is generic and can be applied to other hyperspectral instruments in the future. Having established the retrieval technique, extensive studies of chlorophyll fluorescence will improve global knowledge on physiology and photosynthetic efficiency, in both the marine and terrestrial realms, and its dependence on environmental factors.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S12517-015-1837-0", "year": 2015, "title": "Geoinformatics application for assessing the potential of rainwater harvesting in arid regions. Case study: El Dabaa area, Northwestern Coast of Egypt", "abstract": "In the light of the current situation of water resources in Egypt, where it has a deficit in those resources, the rainwater harvesting and assessment of its potentialities became necessary. In the present study, an attempt is made to define a decision based on scientific approach for identifying the most appropriate sites for rainwater harvesting. This approach is based on GIS data layers which include DEM, landforms, geologic setting, watershed area, rainfall amounts, drainage lines, morphometric parameters, flow accumulation, flow direction, slope, and surface runoff. It also includes a verification of the site suitability through field investigations. El Dabaa area has been chosen because it has a lack of water for agriculture and drinking purposes. In addition, this area has special interest because of a planned nuclear power plant there. The obtained results reveal that the study area contains eight basins which have slightly intensive drainage network. The morphometric analyses of the studied basins reveal their opportunities for surface runoff. Three of them are showing high hazard degrees. These basins have actual runoff (Q) ranges between 16.5 and 25 mm annually resulted from average rainfall of 164 mm. Therefore, management of rainwater harvesting and protections from flash floods were recommended. Many rainwater harvesting structures, for example concert dams, alternative earth dikes, surface water reservoirs, and cisterns, should be established.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S40710-015-0063-9", "year": 2015, "title": "Framework for Investigation of Karst Aquifer in an Arid Zone, Using Isotopes, Remote Sensing and GIS Applications: the Northwestern Coast of Egypt", "abstract": "The hydrogeology of arid regions is becoming increasingly important due to diminishing projections of water resource availability in response to global environmental change. This paper aims to investigate the karst aquifer in the study area and clarifies the different factors which affect the occurrence and quality of its groundwater. The fractures systems are the main factor which controls the groundwater occurrence in the studied aquifer. The isotope analyses reveal that the groundwater has nearly similar isotopic compositions, suggesting similar recharge conditions; they also indicate that the groundwater of karst aquifer is meteoric water and the recharging source is the rainfall. The high values of total dissolved salts (TDS) of the groundwater are attributed to the rock-water interactions which lead to dissolution processes of marine salts into the aquifer matrix. Although most of the water levels in the drilled wells are under the sea level, the isotope analyses indicate that no contribution of seawater intrusion affects the groundwater. The present study reveals that some specific regions have more priorities than others in future groundwater explorations.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.2989/00306525.2015.1030465", "year": 2015, "title": "Food abundance explains the breeding season of a tropical shorebird, the Crab Plover Dromas ardeola", "abstract": "The timing of breeding in birds is a life-history trait that generally depends on food availability, but other factors may play a role, particularly in tropical areas where food availability is less seasonal than in temperate or polar areas. We studied the factors affecting the breeding season of the Crab Plover Dromas ardeola, a burrownesting colonial shorebird endemic to the north-western Indian Ocean. A reduced risk of burrow flooding, high temperatures suitable for exploiting solar incubation, a reduced interference by Palaearctic shorebirds during foraging, a reduced risk of predation by Palaearctic raptors and a high food abundance are all associated with the summer breeding season of the Crab Plover in our study area in Eritrea. In addition, we collected remotely recorded data associated with these advantageous environmental factors around breeding colonies in nine well-separated areas. Only average annual chlorophyll a concentration, a proxy of marine productivity, was significantly correlated with the start of the breeding season, which varies up to one month throughout the breeding range. We conclude that food abundance, with the likely high intraspecific competition due to coloniality, is strongly supported as the critical factor determining the nesting phenology of this tropical species.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/ECE3.1511", "year": 2015, "title": "Exploring seascape genetics and kinship in the reef sponge Stylissa carteri in the Red Sea", "abstract": "A main goal of population geneticists is to study patterns of gene flow to gain a better understanding of the population structure in a given organism. To date most efforts have been focused on studying gene flow at either broad scales to identify barriers to gene flow and isolation by distance or at fine spatial scales in order to gain inferences regarding reproduction and local dispersal. Few studies have measured connectivity at multiple spatial scales and have utilized novel tools to test the influence of both environment and geography on shaping gene flow in an organism. Here a seascape genetics approach was used to gain insight regarding geographic and ecological barriers to gene flow of a common reef sponge, Stylissa carteri in the Red Sea. Furthermore, a small-scale (<1 km) analysis was also conducted to infer reproductive potential in this organism. At the broad scale, we found that sponge connectivity is not structured by geography alone, but rather, genetic isolation in the southern Red Sea correlates strongly with environmental heterogeneity. At the scale of a 50-m transect, spatial autocorrelation analyses and estimates of full-siblings revealed that there is no deviation from random mating. However, at slightly larger scales (100200 m) encompassing multiple transects at a given site, a greater proportion of full-siblings was found within sites versus among sites in a given location suggesting that mating and/or dispersal are constrained to some extent at this spatial scale. This study adds to the growing body of literature suggesting that environmental and ecological variables play a major role in the genetic structure of marine invertebrate populations.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/CLI3040964", "year": 2015, "title": "Evaluation of Precipitation Climatology Derived from TRMM Multi-Satellite Precipitation Analysis (TMPA) Monthly Product over Land with Two Gauge-Based Products", "abstract": "The NASA/JAXA Tropical Rainfall Measuring Mission (TRMM) has been in operation for over 17 years since 1997. The length of TRMM is far shorter than those from ground observations, raising a question as to whether TRMM derived climatology products are good enough for research and applications. In this study, three climatologies derived from a blended product (the TRMM Multi-Satellite Precipitation Analysis (TMPA) monthly product or 3B43) and gauge-based ground observations (Global Precipitation Climatology Center (GPCC) and Willmott and Matsuura (WM)) are compared over land on a global scale (50 N50 S) to assess the performance and weaknesses of the TMPA-derived climatology. Results show that the 3B43 climatology matches well with the two gauge-based climatologies in all seasons in terms of spatial distribution, zonal means as well as seasonal variations. However, large variations are found in light rain (<0.5 mm/day) regions such as the Sahara Desert. At high rain rates, large negative biases (3B43 < WM < GPCC) are found in orographically influenced regions such as windward sides of monsoon mountains in JJA, which is associated with underestimation of shallow orographic rain rates in microwave radiometer algorithms and sparse gauge data for bias correction. Nonetheless, biases in 3B43 exist and vary with geographic locations due to a number of factors such as gauge availability and algorithm issues.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-15-1447-2015", "year": 2015, "title": "Evaluation of black carbon emission inventories using a Lagrangian dispersion model a case study over southern India", "abstract": "Abstract. We evaluated three emission inventories of black carbon (BC) using Lagrangian particle dispersion model simulations and BC observations from a rural site in southern India (Gadanki; 13.48 N, 79.18 E) from 2008 to 2012. We found that 93 to 95% of the BC load at the observation site originated from emissions in India and the rest from the neighbouring countries and shipping. A substantial fraction (33 to 43%) of the BC was transported from northern India. Wet deposition is found to play a minor role in reducing BC mass at the site because of its proximity to BC sources during rainy season and relatively short rainy season over western and northern parts of India. Seasonally, the highest BC concentration (approx. 3.3 g m3) is observed during winter, followed by spring (approx. 2.8 g m3). While the model reproduced well the seasonal cycle, the modelled BC concentrations are significantly lower than observed values, especially in spring. The model bias is correlated to fire radiative power a proxy of open biomass burning activity. Using potential emission sensitivity maps derived using the model, we suggest that underestimation of BC mass in the model during spring is due to the underestimation of BC fluxes over southern India (possibly from open-biomass-burning/forest-fires). The overall performance of the model simulations using three different emission inventories (SAFAR-India, ECLIPSE and RETRO) is similar, with ECLIPSE and SAFAR-India performing marginally better as both have about 30% higher emissions for India than RETRO. The ratio of observed to modelled annual mean BC concentration was estimated as 1.5 for SAFAR, 1.7 for ECLIPSE and 2.4 for RETRO.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1134/S1024856015030124", "year": 2015, "title": "Estimate of errors and verification of the method of fluid location of the atmosphere", "abstract": "A variant of determining errors in the statistical estimate of the average effective concentration field calculated in the quasi-two-dimensional approximation by the method of fluid location of the atmosphere (FLA) is proposed. Results of the FLA verification by three methods are presented. In spite of the fact that the quasi-two-dimensional approximation has some restrictions, all the considered ways of verification point to the possibility to use the FLA method for estimating average concentration fields of fine aerosol.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JHYDROL.2015.08.062", "year": 2015, "title": "Error characterization of TRMM Multisatellite Precipitation Analysis (TMPA-3B42) products over India for different seasons", "abstract": "A comprehensive error characterization of satellite-based precipitation products is vital for advancement of precipitation algorithms, evaluation of numerical model outputs, and their integration in various hydro-meteorological applications. The Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) products are in high demand to users for numerous applications. The latest version 7 (V7) of TMPA products are assumed to be better than its previous versions due to substantial changes in input data sets and algorithm. The TMPA algorithm is also a benchmark algorithm for the Global Precipitation Measurement (GPM) mission multisatellite precipitation products. In this study, both near-real-time (TMPA-RT) and research-quality (TMPA-V7) TMPA data sets are extensively evaluated against gridded gauge-based data over India for pre-monsoon, monsoon, and post-monsoon seasons at daily scale for a 13-year (20012013) period. The systematic and random error components in TMPA data sets are decomposed for their wider usage in agricultural and hydrological applications. Although TMPA-V7 and RT data sets represent the mean seasonal rainfall characteristics reasonably well, both the satellite-based data sets show an overestimation of rainfall over most parts of the country except over the orographic regions. However, TMPA-V7 is better than TMPA-RT when compared with the reference observations. Both the TMPA products show larger systematic error over the mountainous regions of northeast India. TMPA-RT has larger random error than TMPA-V7 possibly due to difference in calibration methods for the development of these data sets. Both the satellite-based data sets show significant difference from the reference observations for light to moderate rainfall ranges especially in the monsoon season. Larger error associated with systematic component in both the data sets is found during the pre-monsoon season. Furthermore, bias and error in satellite-derived rainfall data show a considerable interannual variation. Overall results suggest that a suitable region and season dependent bias-correction is required in TMPA data sets before its integration in hydrological applications.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S10661-015-4585-4", "year": 2015, "title": "Empirical and semi-analytical chlorophyll a algorithms for multi-temporal monitoring of New Zealand lakes using Landsat", "abstract": "The concentration of chlorophyll a (chl a; as a proxy for phytoplankton biomass) provides an indication of the water quality and ecosystem health of lakes. An automated image processing method for Landsat images was used to derive chl a concentrations in 12 Rotorua lakes of North Island, New Zealand, with widely varying trophic status. Semi-analytical and empirical models were used to process 137 Landsat 7 Enhanced Thematic Mapper (ETM+) images using records from 1999 to 2013. Atmospheric correction used radiative transfer modelling, with atmospheric conditions prescribed with Moderate Resolution Imaging Spectroradiometer (MODIS) Terra and AIRS data. The best-performing semi-analytical and empirical equations resulted in similar levels of variation explained (r2 = 0.68 for both equations) and root-mean-square error (RMSE = 10.69 and 10.43 g L1, respectively) between observed and estimated chl a. However, the symbolic regression algorithm performed better for chl a concentrations <5 g L1. Our Landsat-based algorithms provide a valuable method for synoptic assessments of chl a across the 12 lakes in this region. They also provide a basis for assessing changes in chl a individual lakes through time. Our methods provide a basis for cost-effective hindcasting of lake trophic status at a regional scale, informing on spatial variability of chl a within and between lakes.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS70505283", "year": 2015, "title": "Effect of Cloud Fraction on Near-Cloud Aerosol Behavior in the MODIS Atmospheric Correction Ocean Color Product", "abstract": "Characterizing the way satellite-based aerosol statistics change near clouds is important for better understanding both aerosol-cloud interactions and aerosol direct radiative forcing. This study focuses on the question of whether the observed near-cloud increases in aerosol optical thickness and particle size may be explained by a combination of two factors: (i) Near-cloud data coming from areas with higher cloud fractions than far-from-cloud data and (ii) Cloud fraction being correlated with aerosol optical thickness and particle size. This question is addressed through a statistical analysis of aerosol parameters included in the MODIS (MODerate resolution Imaging Spectroradiometer) ocean color product. Results from ten Septembers (20022011) over part of the northeast Atlantic Ocean confirm that the combination of these two factors working together explains a significant but not dominant part (in our case, 15%30%) of mean optical thickness changes near clouds. Overall, the findings show that cloud fraction plays a large role in shaping the way aerosol statistics change with distance to clouds. This implies that both cloud fraction and distance to clouds are important to consider when aerosol-cloud interactions or aerosol direct radiative effects are examined in satellite or modeling studies.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JHYDROL.2015.08.010", "year": 2015, "title": "Drought or humidity oscillations? The case of coastal zone of Lebanon", "abstract": "There is discrepancy in classifying Lebanon according to the different climatic zones; however, it is often described as a semi-arid region. Lately, Lebanon has been witnessing climatic oscillations in the meteorological parameters. The impact of these oscillations on water sector has been reflected also on energy-food nexus. Yet, there are a number of studies obtained to identify the climate of Lebanon, and they show contradictory results; especially these studies elaborated different datasets and applied diverse methods which often modeled only on large-scale regions. Therefore, the analysis of climatic data depended on complete and long-term climatic records that can be applied to assess the existing climatic status of Lebanon, as well as to assure whether Lebanon is under drought, humidity or it is oscillating between both. This study utilized considerable datasets, from different sources including the remotely sensed systems (e.g. TRMM). These datasets were interpolated and analyzed statistically according to De Martonne Aridity Index. Aiming to affirm the climatic attribute of Lebanon; however, ten climatic stations were investigated. They are with representative geographic setting and diverse time series in the coastal zone of Lebanon were investigated. Even though, Lebanon is known as a semi-arid region, yet results in this study show that the studied zone does not evidence any drought, since around 70% of the investigated years are characterized by semi-humid to humid climate. This climatic figure is well pronounced since rainfall rate exceeds 900mm, average temperature rate is about 19C, and snow remains for a couple of months annually.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1017/S003224741300065X", "year": 2015, "title": "Distribution of gymnosomatous pteropods in western Antarctic Peninsula shelf waters: influences of Southern Ocean water masses", "abstract": "Distributions of gymnosomatous pteropods, Spongiobranchaea australis and Clione antarctica, were determined at six sites along a latitudinal gradient in western Antarctica Peninsula shelf waters using vertically stratified trawls. Hydrographic data were collected at the same sites with conductivity-temperature-depth casts, and correlations of explanatory variables to gymnosome distributions were determined using statistical analyses performed in Matlab, a high level programming software to conduct numerical computation and visualisation. Explanatory variables included sampling site, latitude, longitude and depth, seawater temperature, salinity and density, Southern Ocean Antarctic Surface Water, Winter Water, Upper Circumpolar Deep Water and warm transitional waters, as well as oceanographic remote sensing data for coloured dissolved organic matter, chlorophyll a concentration, normalised fluorescence line height, nighttime sea surface temperature, photosynthetically active radiation, particulate inorganic carbon, particulate organic carbon, daytime sea surface temperature and daily sea ice concentration. Hydrographic data revealed that warmer water masses were prevalent along the western Antarctic Peninsula, and the distributions of both gymnosome species were primarily influenced by water masses, temperature, sampling site and latitude. As a consequence, distributional shifts of gymnosomes are predicted in response to the current warming trends.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1371/JOURNAL.PONE.0132681", "year": 2015, "title": "Dissolved Oxygen Sensor in Animal-Borne Instruments: An Innovation for Monitoring the Health of Oceans and Investigating the Functioning of Marine Ecosystems", "abstract": "The current decline in dissolved oxygen concentration within the oceans is a sensitive indicator of the effect of climate change on marine environment. However the impact of its declining on marine life and ecosystems health is still quite unclear because of the difficulty in obtaining in situ data, especially in remote areas, like the Southern Ocean (SO). Southern elephant seals (Mirounga leonina) proved to be a relevant alternative to the traditional oceanographic platforms to measure physical and biogeochemical structure of oceanic regions rarely observed. In this study, we use a new stage of development in biologging technology to draw a picture of dissolved oxygen concentration in the SO. We present the first results obtained from a dissolved oxygen sensor added to Argos CTD-SRDL tags and deployed on 5 female elephant seals at Kerguelen. From October 2010 and October 2011, 742 oxygen profiles associated with temperature and salinity measurements were recorded. Whether a part of the data must be considered cautiously, especially because of offsets and temporal drifts of the sensors, the range of values recorded was consistent with a concomitant survey conducted from a research vessel (Keops-2 project). Once again, elephant seals reinforced the relationship between marine ecology and oceanography, delivering essential information about the water masses properties and the biological status of the Southern Ocean. But more than the presentation of a new stage of development in animal-borne instrumentation, this pilot study opens a new field of investigation in marine ecology and could be enlarged in a near future to other key marine predators, especially large fish species like swordfish, tuna or sharks, for which dissolved oxygen is expected to play a crucial role in distribution and behaviour.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-15-12731-2015", "year": 2015, "title": "Direct radiative effect by brown carbon over the Indo-Gangetic Plain", "abstract": "Abstract. The importance of light-absorbing organic aerosols, often called brown carbon (BrC), has become evident in recent years. However, there have been relatively few measurement-based estimates for the direct radiative effect of BrC so far. In earlier studies, the AErosol RObotic NETwork (AERONET)-measured aerosol absorption optical depth (AAOD) and absorption Angstrom exponent (AAE) were exploited. However, these two pieces of information are clearly not sufficient to separate properly carbonaceous aerosols from dust, while imaginary indices of refraction would contain more and better justified information for this purpose. This is first time that the direct radiative effect (DRE) of BrC is estimated by exploiting the AERONET-retrieved imaginary indices. We estimated it for four sites in the Indo-Gangetic Plain (IGP), Karachi, Lahore, Kanpur and Gandhi College. We found a distinct seasonality, which was generally similar among all the sites, but with slightly different strengths. The monthly warming effect up to 0.5 W m2 takes place during the spring season. On the other hand, BrC results in an overall cooling effect in the winter season, which can reach levels close to 1 W m2. We then estimated similarly also the DRE of black carbon and total aerosol, in order to assess the relative significance of the BrC radiative effect in the radiative effects of other components. Even though BrC impact seems minor in this context, we demonstrated that it is not insignificant. Moreover, we demonstrated that it is crucial to perform spectrally resolved radiative transfer calculations to obtain good estimates for the DRE of BrC.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2014JD022658", "year": 2015, "title": "Dimming over the oceans: Transient anthropogenic aerosol plumes in the twentieth century", "abstract": "Anthropogenic aerosols reduce incoming surface solar radiation (SSR), but the magnitude of this effect for reducing sea surface temperatures (SST) is still debated. Using simulations from the global climate model ECHAM5 with the Hamburg Aerosol Module and prescribed SSTs, we quantify anthropogenic aerosol dimming over sea surfaces by comparing ensembles, which only differ in anthropogenic aerosol emissions. We isolate the anthropogenic aerosol effect on SSR with sufficiently large ensemble sizes to provide statistically significant results. The following simulation results are obtained: Dimming plumes extend from their source regions with clear seasonality. The latter is predominantly shaped by atmospheric circulation, while interdecadal changes follow the gradual increase in anthropogenic aerosol emissions. Comparing the 1990s with the 1870s, on average, 9.4% (clear-sky SSR) or 15.4% (all-sky SSR) of the entire ocean surface was affected by anthropogenic aerosol dimming larger than 4 Wm2 (decadal mean). Comparing the same time periods, global average anthropogenic dimming over oceans is 2.3 Wm2 and 3.4 Wm2 for clear-sky and all-sky SSR, respectively. Surface dimming is hemispherically asymmetrical with stronger Northern Hemispheric dimming by 2.3 Wm2 and 4.5 Wm2 for clear-sky and all-sky SSR, respectively. Zonal average clear-sky dimming reaches its maximum (5.5 Wm2) near the equator. All-sky dimming peaks at 40N (8 Wm2) and is regionally larger than clear-sky dimming. Regionally, surface dimming can reach values up to 9.5 Wm2 (clear-sky) and 25 Wm2 (all-sky). Results are a contribution toward better quantifying spatially heterogeneous and time-dependent anthropogenic dimming effects on SSTs.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ISPRSJPRS.2015.03.012", "year": 2015, "title": "Diffuse sky radiation influences the relationship between canopy PRI and shadow fraction", "abstract": "The Photochemical Reflectance Index (PRI) of green leaves is an indicator of photosynthetic downregulation: when the photosynthetic apparatus is close to the saturation limit, PRI becomes dependent on light conditions. Therefore, by measuring the PRI of leaves under different local irradiance conditions, it should be possible to determine the saturation level of the leaves and obtain information on the light use efficiency (LUE) of a vegetation canopy. The dependence of PRI on the ratio of sunlit to shaded foliage (quantified by the canopy shadow fraction) in the field of view of an instrument has been used to remotely measure canopy LUE on clear days. However, besides photosynthetic downregulation, the dependence of canopy PRI on shadow fraction is affected by the blue sky radiation caused by scattering in the atmosphere. To quantify this effect on remotely sensed PRI, we present the underlying definitions relating leaf and canopy PRI and perform the required calculations for typical midsummer conditions in Central Finland. We demonstrate that the effect of blue sky radiation on the variation of PRI with canopy shadow fraction is similar in shape and magnitude to that of LUE variations reported in literature.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5539/JGG.V7N2P70", "year": 2015, "title": "Development of Flood Forecasting System for the Wangchhu River Basin in Bhutan", "abstract": "In mountainous countries like Bhutan, floods are potentially serious dangers for communities since they triggersubsequent hazards such as landslides. The countries lying in the Himalayan Mountain are exposed to floodsowing to the heavy rainfall and glacial lake outburst floods. The forecasting of catastrophic flood hazards iscrucial for the sustainability of these mountainous countries. At the same time, the hydro-met observation systemis inadequate to set up a robust flood-forecasting model in Bhutan. This paper focuses on developing a floodforecasting model for the Wangchhu river basin in Bhutan, by assimilating the hydrological gauge data andsatellite rainfall, and by providing stream flow frequency, rating curve and stream characteristics of theWangchhu basin. The study depicts the poor efficiency without upstream rainfall gauges. Using satellite databasewith proxy stations in the upper catchments increase the accuracy of the model. The Weather Research Forecast(WRF) model generated 3-day rainfall forecasts, which were used to generate flow forecasting. The WRF resultfor Bhutan is poor; thus, other sources of rainfall prediction need to be incorporated in the model. The model hasbeen calibrated for 2003-2004 and validated for 2005, 2009 and 2010 data.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/978-3-319-13865-7_13", "year": 2015, "title": "Detecting CDOM Fluorescence Using High Spectrally Resolved Satellite Data: A Model Study", "abstract": "Absorption and fluorescence of CDOM are widely used to characterize its concentration and composition, both in situ and with remote sensing techniques. As fluorescence is an inelastic scattering process, it can potentially be observed in filling-in of Fraunhofer lines with the DOAS method in high spectrally resolved satellite data. Here, we perform a theoretical model study and preliminary DOAS retrieval on SCIAMACHY data in order to test the feasibility of such an approach. Our results show that retrieving CDOM fluorescence is difficult, due to its relatively weak signal in global oceans (in comparison to Raman scattering of clear water) and varying broad spectral features. Detailed studies of the synergistic use of narrow and broad fluorescence features, and an appropriate scheme to account for disturbance effects of Raman scattering, are needed for further investigating the retrieval of CDOM fluorescence.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1890/ES14-00508.1", "year": 2015, "title": "Decomposing the variance in southern elephant seal weaning mass: partitioning environmental signals and maternal effects", "abstract": "Predator populations are likely to respond to bottom-up processes, but there remains limited understanding of how wide-ranging marine predators respond to environmentally driven temporal variation in food availability. Widespread declines of several Southern Ocean predators, including southern elephant seals Mirounga leonina, have been attributed to decreases in food availability following environmental changes. We used linear mixed models to examine temporal process variance in weaning mass (a key fitness component) of southern elephant seals at Marion Island over a 27-year period (19862013). We quantified the contribution of within- and between-year covariates to the total phenotypic variance in weaning mass and determined whether the observed reversal of population decline was associated with a continued increase in weaning mass, suggesting improvement in per capita food availability to adult females. Weaning mass initially increased rapidly with maternal age, but reached an asymptote when females were nine years old. Longitudinal data examining between-individual maternal differences suggested latent, age-independent maternal influences on weaning mass. Between-year differences accounted for only 6% of the total phenotypic variance in weaning mass. We found no evidence for a systematic trend in weaning mass, but model predicted weaning mass was 8.70 kg (95% CI = 2.1414.73) lower during the 1980s, suggesting that food limitation may have been most severe during these years when the population was declining. Model support for a population size effect was entirely driven by the low weaning mass and comparatively high (but declining) population size from 1986 to 1988; subsequent variation in population size had no detectable influence on weaning mass. Remotely sensed chlorophyll-a concentration within the seals' foraging distribution explained 45% of the between-year variation (19982013, n = 9) in weaning mass, with higher weaning mass in years of positive chlorophyll-a anomalies. Environmental variation associated with variability in the Southern Annular Mode poorly predicted temporal variation in weaning mass. Our long-term data on elephant seal weaning mass provides a perspective on variation in food availability in a pelagic environment which is poorly known. Examining the long-term regionally specific effects of environmental variability aids our understanding of how these predators interact with their environment.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1080/01431161.2015.1070317", "year": 2015, "title": "Correlation between the spatio-temporal distributions of aerosols, sulphur dioxide, and formaldehyde using MODIS and SCIAMACHY satellite data for China", "abstract": "The spatial and temporal relationship between fine-mode aerosol optical depth (AOD) observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) and tropospheric columns of SO2 and formaldehyde (HCHO) from the Scanning Imaging Absorption Chartography (SCIAMACHY) are used to infer information on the variability of sulphate aerosol, which is a major determinant of fine-mode AOD (AODf) in east China. When averaging the satellite data over specific regions of China and for longer time periods (from 2005 to 2011), we find obvious similar trends between AODf and SO2, HCHO columns for southern and eastern China. The results of satellite observations show the high spatial and temporal correlation between AODf and SO2 over the Yangtze River Delta (R2), the Pearl River Delta (R3), and the ChongqingChengdu region (R4), with the coefficients of determination (R2) of 0.376, 0.438, and 0.837, respectively. These regions are performing with the huge amount of anthropogenic SO2 emissions by traffic, industry, and domestic heating. The trend is consistent with fine-mode aerosol and SO2 appearing in summer because AODf is often correlated with enhanced HCHO concentrations, reflecting the importance of secondary aerosol formation over industrialized regions in that season. Over the North China Plain, distinct maximum values of AODf and HCHO were observed and the minimum value for SO2 was observed in summer. The decrease in the mean SO2 column was 35.5%, which has been attributed to the strict security measures by the government during the 2008 Olympic Games period while there was a decrease of 46% in AODf at the same time. As sulphate aerosol occurs seasonally in the North China Plain, the strong correlation between anomalies of AODf and SO2 can be used to estimate and analyse the distribution of sulphate aerosol. Singular value decomposition (SVD) analysis showed the same variation between AODf and SO2 over eastern China and Sichuan Province, and a distinct negative value of SVD variables over comparably industrialized regions in southern and eastern China and Sichuan Province. The results for SO4 from the Model for Ozone and Related chemical Tracers model for southern and eastern China and the Sichuan regions suggest much stronger sulphate contributions to aerosol formation than for other areas of China. We propose that the SVD variables between AODf and SO2, which can be inferred from the satellite data, can be used as indicators for regional pollution control.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.4209/AAQR.2014.08.0168", "year": 2015, "title": "Correlation Analysis between AOD and Cloud Parameters to Study Their Relationship over China Using MODIS Data (2003-2013): Impact on Cloud Formation and Climate Change", "abstract": "ABSTRACTIn the present study, we examined the spatial and temporal variations in aerosol optical depth (AOD) at 550 nm and its relationship with various cloud parameters derived from the Moderate resolution Imaging Spectroradiometer (MODIS) sensor onboard Terra satellite. The data have been analyzed for the period of 10-years between March 2003 and February 2013 over 12 major cities in China. The results revealed that high AOD noticed over low latitude regions influenced with high anthropogenic activities and the low AOD observed for the high altitude and mountainous areas, since AOD accounts for the slant path which reduces the aerosol emissions. In addition, the aerosol variations in the atmosphere are complicated by several factors in emissions (natural and anthropogenic) as well as stagnant synoptic meteorology. From the temporal studies, it is clear that the maximum AOD was found during summer followed by spring and autumn with a minimum AOD in winter season for all the regions of study in China. Furthermore, we studied the relationship between AOD versus water vapor (WV), cloud fraction (CF), cloud optical thickness (COT), cloud effective radius (CER), cloud top pressure (CTP), and cloud top temperature (CTT) for the selected regions in China. Additionally, regression analysis and one paired students t-Test were applied to represent the probability of data significant at 95% confidence for the derived AOD values and cloud parameters in order to provide a better understanding of aerosol-cloud interaction.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.POCEAN.2015.06.010", "year": 2015, "title": "Complex interplay of physical forcing and Prochlorococcus population in ocean", "abstract": "Physical forcing can replenish nutrients within the mixed layer by convective mixing or via upwelling. Conventional wisdom holds this enrichment fuels phytoplankton growth, for example ventilation of subsurface water during winter monsoon is known to enhance primary productivity in the northern Arabian Sea. One important numerically dominant phytoplankton known to have ecological niche in the ocean is Prochlorococcus. In the Arabian Sea, they occur in oligotrophic surface water and below the oxycline representing two different light and biogeochemical regimes. Here we show convective mixing in the northern Arabian Sea inhibits Prochlorococcus growth owing to change in physical environment. Pigment observations carried out during early and peak winter monsoon revealed contrasting picoplankton distribution. Divinyl chlorophyll a (a marker for Prochlorococcus) which was the most abundant picoplankton pigment during early winter monsoon was not detected with the onset of winter convection covarying with high nutrients in the surface water. We propose two possible mechanisms for such sudden disappearance which involves changes in light and biogeochemical regimes. This physico-chemical control could be critical for their existence but not limited to and can play an important role in regions experiencing such phenomenon. We also highlight the linkages between Prochlorococcus succession and basin scale dynamics from the Arabian Sea which hitherto remains poorly understood.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/01431161.2014.999880", "year": 2015, "title": "Comparison and evaluation of dust detection algorithms using MODIS Aqua/Terra Level 1B data and MODIS/OMI dust products in the Middle East", "abstract": "Dust storms have a major impact on air quality, economic loss, and human health over large regions of the Middle East. Because of the broad extent of dust storms and also politicalsecurity issues in this region, satellite data are an important source of dust detection and mapping. The aim of this study was to compare and evaluate the performance of five main dust detection algorithms, including Ackerman, Miller, normalized difference dust index (NDDI), Roskovensky and Liou, and thermal-infrared dust index (TDI), using MODIS Level 1B and also MODIS Deep Blue AOD and OMI AI products in two dust events originating from Iraq and Saudi Arabia. Overall, results showed that the performance of the algorithms varied from event to event and it was not possible to use the published dust/no-dust thresholds for the algorithms tested in the study area. The MODIS AOD and OMI AI products were very effective for initial dust detection and the AOD and AI images correlated highly with the dust images at provincial scale (p-value <0.001), but the application of these products was limited at local scale due to their poor spatial resolution. Results also indicated that algorithms based on MODIS thermal infrared (TIR) bands or a combination of TIR and reflectance bands were better indicators of dust than reflectance-based ones. Among the TIR- based algorithms, TDI performed the best over water surfaces and dust sources, and accounted for approximately 93% and 90% of variations in the AOD and OMI AI data.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/MET.1502", "year": 2015, "title": "Comparing two high-resolution gauge-adjusted multisatellite rainfall products over India for the southwest monsoon period", "abstract": "Reliable high-resolution rainfall estimates are vital for hydrological and weather/climate-related applications and evaluation of high-resolution numerical model outputs. Multisatellite rainfall products provide immense opportunities to analyse rainfall at regular spatial and temporal scales, but suffer from large region- and season-dependent biases. Direct calibration or merging of ground-based observations with multisatellite rainfall estimates essentially provides more accurate rainfall estimates as it benefits from the relative merits of both the sources. In this study, two popular gauge-adjusted multisatellite rainfall products, the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) research monitoring 3B42 version 7 (3B42V7) and Climate Prediction Center (CPC) Rainfall Estimation Algorithm version 2 (RFE2.0) are compared with the recently released and improved gridded India Meteorological Department (IMD) gauge-based rainfall estimates over India. The comparison is done for a 13 year southwest monsoon season ranging from 2001 to 2013 at 0.25 latitude/longitude resolution. A number of skill metrics such as mean, bias, co-efficient of variation, correlation co-efficient, anomaly correlation, pattern correlation and root-mean-square error (RMSE) are computed to assess the accuracy of both the merged satellite-gauge rainfall products. The prominent Indian monsoon rainfall features are well captured by both 3B42V7 and RFE2.0 products, in general. However, they overestimate mean rainfall at the all-India scale and the overestimation is comparatively larger for RFE2.0 than for 3B42V7. Even though the interannual variability of the Indian monsoon rainfall from both the gauge-adjusted multisatellite data sets is comparable with the gauge-based estimates for the study period, RFE2.0 overestimates light rainfall and underestimates heavy rainfall. Moreover, the comparison at sub-regional scales shows that 3B42V7 overestimates rainfall over eastern India and the foothills of the Himalayas and underestimates along the west coast and over the northeast, whereas RFE2.0 underestimates monsoon rainfall over the three sub-regions except over eastern India where it overestimates rainfall by about 25%. Both the gauge-adjusted multisatellite rainfall products show larger RMSE of the order of 100% along the west coast of India, which is a cause of concern. Overall analysis suggests that 3B42V7 is superior to RFE2.0 at synoptic scale over the Indian monsoon region.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1111/MAEC.12166", "year": 2015, "title": "Collapse of zooplankton stocks during Liriope tetraphylla (Hydromedusa) blooms and dense mucilaginous aggregations in a thermohaline stratified basin", "abstract": "A growing number of studies report an increase in jellyfish populations worldwide that may have consequences for marine planktonic food web dynamics. The principal objective of this study was to understand the changes in a zooplankton community during blooms of Liriope tetraphylla and subsequent mucilage events in the Sea of Marmara, a small highly stratified transitional basin between the Black and Aegean Seas. Liriope blooms observed in 2006 and 2007 reached a maximum abundance of 2978 ind.m3, following the species' first observation in 2005. Jellyfish species are known to play a key guild role by restructuring plankton communities and in the Sea of Marmara Liriope caused a temporal regime shift from a crustacean- to a jellyfish-controlled system. A rapid decline in abundance of most important zooplankton species followed the Liriope increase, together with a drastic shift in community structure. The dominant summerautumn species Penilia avirostris (Cladocera) vanished in the autumn of 2006 and was diminished 30-fold in 2007 when compared with years without Liriope. The decline in zooplankton and the devastating effects of mucilage on pelagic ecosystem and socio-economics through restricting commercial fisheries implied sensitivity of the already perturbed Marmara ecosystem to changes in predator densities and environmental stability.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5897/SRE2014.6061", "year": 2015, "title": "Coastal climate and beach dynamics at Ponta do Ouro, Mozambique", "abstract": "Annual field surveys conducted at Ponta do Ouro in Southern Mozambique have determined that coastal variability is driven by high wave energy and consequent northward longshore drift. There is a log-spiral headland-bay system marked by 80 m tall forested dunes in the south that give way to a broad flat sandy beach. Marine climate processes that affect coastal erosion and accretion are studied using local and remote data sets. Since surveys began, the climate has undergone a prolonged dry spell (2002-2007) followed by increased run-off and easterly winds (2010-2013) that have re-built the beaches. Sand grain sizes vary from 240 - 410 m (coarser south finer north) and are mobilized by frequent longshore wind events > 10 m/s. Ocean drifters reveal a northward current in the outer surf zone of 0.6 m/s and an onshore gyre of 0.1 m/s in the recessed bay. Wave-driven sand transport is estimated at 5 106 kg/yr/m. While the upper beach has flattened due to pedestrian traffic and urban development, the lower beach has recovered from erosion due to a greater frequency of easterly waves and rainy weather.\n\n\t \n\n\tKey words: Beach, coastal erosion, marine climate.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/2014JD022611", "year": 2015, "title": "Climatic controls on the interannual to decadal variability in Saudi Arabian dust activity: Toward the development of a seasonal dust prediction model", "abstract": "The observed climatic controls on springtime and summertime Saudi Arabian dust activities during 19752012 are analyzed, leading to development of a seasonal dust prediction model. According to empirical orthogonal function analysis, dust storm frequency exhibits a dominantly homogeneous pattern across Saudi Arabia, with distinct interannual and decadal variability. The previously identified positive trend in remotely sensed aerosol optical depth since 2000 is shown to be a segment of the decadal oscillation in dust activity, according to long-duration station record. Regression and correlation analyses reveal that the interannual variability in Saudi Arabian dust storm frequency is regulated by springtime rainfall across the Arabian Peninsula and summertime Shamal wind intensity. The key drivers of Saudi Arabian dust storm variability are identified. Winter-to-spring La Nina enhances subsequent spring dust activity by decreasing rainfall across the country's primary dust source region, the Rub' al Khali Desert. A relatively cool tropical Indian Ocean favors frequent summer dust storms by producing an anomalously anticyclonic circulation over the central Arabian Peninsula, which enhances the Shamal wind. Decadal variability in Saudi Arabian dust storm frequency is associated with North African rainfall and Sahel vegetation, which regulate African dust emissions and transport to Saudi Arabia. Mediterranean sea surface temperatures (SSTs) also regulate decadal dust variability, likely through their influence on Sahel rainfall and Shamal intensity. Using antecedent-accumulated rainfall over the Arabian Peninsula and North Africa, and Mediterranean SSTs, as low-frequency predictors, and tropical eastern Pacific and tropical Indian Ocean SSTs as high-frequency predictors, Saudi Arabia's seasonal dust activity is well predicted.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10530-014-0764-4", "year": 2015, "title": "Climate-induced range shifts of the American jackknife clam Ensis directus in Europe", "abstract": "Mapping the future potential distribution of alien species has become an issue of great concern. Ecological niche models are increasingly used to forecast the spatial range of introduced species in the context of climate warming. Here, we studied the potential spread of the American jackknife clam Ensis directus into European waters. E. directus, a marine bivalve native to the American coasts, was observed in Europe for the first time in the German Bight at the end of the 1970s. Afterwards, the clam quickly colonized the surrounding waters of the North Sea. Although many studies focused on its biology, ecology and colonization, the extent to which E. directus may invade European and Nordic seas remained poorly known. In this study, we used two ecological niche models (ENMs), calibrated on the native area of the mollusk, to evaluate the potential distributional range of the bivalve over European seas. Under current environmental conditions, E. directus should continue to progress towards the southern coasts of France and may also invade new areas in the Adriatic Sea. Projections for the end of the century suggest that the probability of occurrence of E. directus increases from Denmark to France with both ENMs. The Tunisian coasts may also become a new suitable area for the mollusk but the results of the two ENMs differ for this region. Therefore, contrary to what is often observed, a southward range expansion of E. directus is probable, especially as climate will get warmer.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1093/ICESJMS/FSV006", "year": 2015, "title": "Characterizing upper-ocean mixing and its effect on the spring phytoplankton bloom with in situ data", "abstract": "Abstract. Since publication, the Sverdrup hypothesis, that phytoplankton are uniformly distributed within the ocean mixed layer and bloom once the ocean warms", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSRES.2015.06.003", "year": 2015, "title": "Characteristics of 14C and 13C of carbonate aerosols in dust storm events in China", "abstract": "In contrast with its decrease in western China deserts, the dust storm event in eastern China, Korea, and Japan shows an increase in frequency. Although the drylands in northeastern China have been recognized as an important dust source, the relative contributions of dust transport from the drylands and deserts are inconclusive, thus the quantification of dust storm sources in downwind area remains a challenge. We measured the 14C and 13C contents in carbonates of dust samples from six sites in China, which were collected for the duration of dust storm events in drylands, deserts, and urban areas. The 13C of the dryland dust samples considerably varied in a range of 9.7 to 5.0, which partly overlapped the desert dust carbonate 13C ranges. The 14C content of the dryland dust carbonates showed a narrow range of 60.94.0 (as an average and 1 SD of five samples) percent modern carbon (pMC), indicating the enrichment of modern carbonate. Dust samples in desert regions contained relatively aged carbonates with the depleting 14C showing of 28.83.3pMC. After the long-range transport of the western China desert dust plume, the carbonates collected at the southern China remained the depletion of 14C (33.55.3pMC) as in the desert regions. On the other hand, the samples of dust storm events at the urban areas of eastern China showed an enrichment of 14C contents (46.25.0pMC, n=7), which might be explained by the stronger contribution of modern-carbonate-rich dryland dust.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.RADMEAS.2015.04.001", "year": 2015, "title": "Characteristic behavior of water radon associated with Wenchuan and Lushan earthquakes along Longmenshan fault", "abstract": "In China, numerous subsurface, surface water well and spring parameters are being monitored through a large network of stations distributed in China sponsored by China Earthquake Administration (CEA). All the data from these network is managed by China Earthquake Network Center (CENC). In this paper, we have used numerous data (water radon, gas radon, water level, water temperature) available through CENC for the period 20022014 and studied the behavior and characteristics of water 222radon [Rn(w)]. The observed parameters were also complemented by rainfall data retrieved from Tropical Rainfall Measuring Mission (TRMM) satellite. Our detailed analysis shows pronounced changes in the observed parameters (especially water and gas radon) prior to the earthquake. The changes in water radon, ground water level and rainfall showing characteristics behavior for Wenchuan and Lushan earthquakes. The long term data analysis of water radon and water level at various locations around epicenters of two major earthquakes along Longmenshan fault show a positive and negative relation of water radon and water level prior to these earthquakes. It is difficult to find any trend of water radon and changes in water radon pattern with these two earthquakes that could prove as a reliable precursor of earthquakes. Changes in the water radon concentrations from one location to other may be associated with the changes in ground water regime and geological settings in the epicentral and surrounding regions.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.MARCHEM.2015.02.009", "year": 2015, "title": "Changes in the distribution of Al and particulate Fe along A16N in the eastern North Atlantic Ocean between 2003 and 2013: Implications for changes in dust deposition", "abstract": "Particulate Al and Fe and dissolved Al concentrations were analyzed in seawater samples from the upper 1000m of the eastern North Atlantic Ocean along the CLIVAR/CO2 Repeat Hydrography Program section A16N in summer 2013, repeating trace metal observations made along the A16N transect a decade earlier. Upper-ocean trace metal distributions in the equatorial and subtropical regions of the North Atlantic are heavily influenced by atmospheric aerosol sources. Using changes in the concentrations of subsurface particulate Al and Fe and mixed-layer dissolved Al in the equatorial North Atlantic, we estimate dust deposition to surface waters in the eastern North Atlantic increased by approximately 15% between 2003 and 2013. Increased concentrations of dissolved Al in subtropical mode waters suggest that dust deposition may have also increased in the western basin. Our observations are consistent with recent reports linking increasing sea surface temperatures in the tropical North Atlantic to increased removal of atmospheric dust via precipitation over the past several decades and highlight the importance of accurate representation of dust deposition processes for modeling Fe biogeochemistry.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JMARSYS.2014.10.015", "year": 2015, "title": "Changes in deep-sea fish and crustacean communities at 10002200m in the Western Mediterranean after 25years: Relation to hydro-climatic conditions", "abstract": "Long-term changes in the biomass, diversity and composition of deep-living fish and decapods from the Balearic Basin (western Mediterranean) have been compared between two periods, 19851992 vs. 20072012, based on 106 bottom trawls performed at 10002250m. Relationships have been identified between the changes in community composition and the hydroclimatic conditions (e.g. NAO, temperature, salinity and dissolved O2) of the area. We found a generalized deepening of middle-slope communities (9501250m), especially among decapods, which is suggested (from GLM results) to have been a response to the long-term increase in salinity of the Levantine Intermediate Waters (LIW), located above the level sampled to ca. 700m. Even more pronounced was the shallowing of all of the lower slope species (16002250m), accompanied by a significant decrease of biomass from 19851992 to 20072012. This last tendency would be done to a combination of factors: long-term decrease of O2 in the bottom-boundary layer, greater degradation of POM arriving on the bottom due to temperature increase in the Western Mediterranean Deep Waters (WMDW) and probably a decrease of Chl a at the surface and, thus, of production. The influence of climatic oscillations (NAO) on differences found between 19851992 and 20072012 seems secondary, likely because the NAO did not show significant differences between the two periods. Some plankton-feeding species showed an increase of density during high/positive NAO (e.g. Alepocephalus rostratus), while some benthos feeders increased during low/negative NAO (e.g. Aristeus antennatus, mainly juveniles). The increase of rainfall and advective fluxes under low/negative NAO (i.e., in 20072012) may increase the formation of the nepheloid layer identified over 12001400m in the area (Cartes et al., 2013a), linked to zooplankton aggregation in that depth range. Greater food availability could explain the generalized migration by both middle and lower slope species toward these intermediate depths that acquired greater trophic resources. Deep-sea Mediterranean fish and invertebrates, including important commercial species, seemed to undergo long-term changes in its distribution and biomass due to changes in hydro-climatic conditions, mainly a decrease of O2 in the bottom-boundary layer.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JMARSYS.2014.10.016", "year": 2015, "title": "Cetacean occurrence and spatial distribution: Habitat modelling for offshore waters in the Portuguese EEZ (NE Atlantic)", "abstract": "In the Portuguese Economic Exclusive Zone (EEZ) (NE Atlantic), little survey effort dedicated to cetacean species has been carried out in offshore waters. As a consequence, data on their occurrence, distribution and habitat preferences is scarce. In this area, 48 sea surveys along fixed transects within Continental Portugal and Madeira Island were performed in 2012 and 2013, from July to October, using platforms of opportunity. We used an environmental envelope approach and GAM habitat models to identify the role of oceanographic, topographic and geographical variables in shaping cetacean distribution. Results demonstrate the richness of offshore waters in this area as in 10,668nmi sampled, we recorded 218 sightings from at least nine cetacean species, resulting in an overall ER of 2.04 sightings/100nmi. The interaction of topographic and oceanographic features was shown to influence the distribution of the species/groups along the routes. Among the sighted species, only common dolphin showed a preference for coastal waters, while for all the other species high seas proved to be determinant. This result reinforces the need to address conservation issues in open ocean. This preliminary assessment showed the importance of the entire area for the distribution of different cetacean species and allowed the identification of several species/group specific potential suitable habitats. Considering the Habitats Directive resolutions, ACCOBAMS priorities, EEZ extension for the area and Maritime Spatial Planning Directive, and the urgent need for management plans, we suggest that the sampling strategy here presented is a cost-effective method to gather valuable data, to be used to improve cetacean habitat models in the area.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.CHEMOSPHERE.2014.08.038", "year": 2015, "title": "Brown haze types due to aerosol pollution at Hefei in the summer and fall", "abstract": "Brown haze episodes were evaluated at Hefei in the summer (JuneAugust) and fall (SeptemberNovember) seasons, and typical haze types were identified by air-mass back-trajectories and fire spot maps. Compared with clear weather conditions, larger median single scattering albedo values of 0.82 and 0.78 at 550nm were obtained for the summer and fall haze episodes, respectively. Further, the observed lower scattering Angstrom exponents imply that more large particles than small particles dominated the haze plumes, which is in agreement with the profiles of size distribution. Particles during a haze episode in Hefei grow to a size such that the 0.10 limit for the backscattering ratio is reached, which may indicate that the aged aerosols promote the formation of haze episodes. Three typical haze types were identified: biomass burning, anthropogenic industrial and traffic emissions, and brown carbon. Less negative aerosol radiative forcing efficiencies of 12.7 and 10.9Wm2 in summer and fall were estimated, respectively, for haze impacted by biomass burning, which emphasizes an enhanced significance of biomass burning aerosols on climate forcing.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/978-3-662-45201-1_28", "year": 2015, "title": "Biology of Red Sea Corals: Metabolism, Reproduction, Acclimatization, and Adaptation", "abstract": "Coral reefs are the most abundant shallow water ecosystems in the Red Sea, harboring a high species diversity and habitat complexity over large environmental gradients. At the same time the semi-enclosed ocean basin and its partly extreme environmental conditions may promote species evolution being distinct from Indo-Pacific coral reefs. Extreme conditions are found in the southern Red Sea, where temperatures reach up to 33 C in summer and where nutrient input is high. Mechanisms of organism adjustment to these conditions are of particular interest in the light of climate change research. Towards the north, conditions become more coral-promoting finally reaching temperatures between 2127 C (winter-summer) and clear waters at the northern end of the Red Sea (Gulf of Aqaba). In this chapter, we summarize the current knowledge about the biology of shallow water, symbiotic, reef-building corals of the Red Sea. We start with an overview on the environmental conditions of the Red Sea, the history of coral reef research in this region and a general introduction into coral biology, before we describe the ecophysiology of Red Sea corals. Coral ecophysiology is presented in the context of varying environmental conditions over depth (e.g., light), between seasons, and over latitudes (e.g., light, temperature, nutrients). Mechanisms and patterns of coral reproduction are discussed in the context of seasonal and latitudinal environmental changes. Finally, we briefly describe anthropogenic influences on Red Sea coral reefs. Acclimatization mechanisms of corals to changing conditions over a depth gradient (mainly light reduction) have been well studied in the Gulf of Aqaba and include the following metabolic adjustments with depth: (i) an upregulation of light-harvesting pigments (chlorophyll a) and a downregulation of photo-protective pigments (xanthophyll), (ii) an increase of heterotrophy, and (iii) a decrease of metabolic activity (e.g., calcification and growth). In addition, a change in the symbiont composition (Symbiodinium clade and/or type) over depth was observed in some coral species. Seasonal environmental changes (mainly light availability, temperature, nutrients) lead to various metabolic responses of the corals, including (i) changes in zooxanthellae pigmentation and density and (ii) changes in the metabolic activity. In particular, changes in calcification and growth rates can be observed with lowest rates during low temperatures in winter. Interestingly, however, this reverses in the southern Red Sea, where calcification rates are higher in winter than in summer. This kind of latitudinal shift is also evident in the timing of reproduction, which occurs earlier in the year (JanuaryMarch) in the south compared to the north (MarchAugust). This indicates that growth and reproduction are strongly linked to temperature, following a single temperature optimum, which occurs at different times throughout the year from north to south. Furthermore, this hints towards a high phenotypic plasticity (acclimatization) rather than local genetic adaptation of the investigated coral species. A clear shift in the genetic population structure from north to south in another coral species, however, indicates local adaption. Adjusting mechanisms need to be further understood in order to provide indication for predicted climate change effects.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3354/AME01746", "year": 2015, "title": "Bacterial and archaeal biogeography of the deep chlorophyll maximum in the South Pacific Gyre", "abstract": "We used 16S rRNA gene tag pyrosequencing to examine the biogeography of bacterial and archaeal community composition in the deep chlorophyll maximum (DCM) of the South Pacific Gyre (SPG), the largest and most oligotrophic region of the world ocean. Dominant DCM bacterial taxa, including Prochlorococcus, SAR11, SAR406, and SAR86, were present at each sampled site in similar proportions, although the sites are separated by thousands of kilometers and up to 100 m in water depth. Marine Group II (MGII) and MGIII Euryarcheota dominated the archaeal assemblages of the DCM at these sites. Bray-Curtis indices show that assemblage composition of these sites is >70% similar for Bacteria and >80% similar for Archaea. Despite these similarities, communities of the central SPG, the western SPG margin, and the southern SPG margin are distinguishable from each other. Comparison of our bacterial results to samples from the DCM of the North Pacific Gyre (NPG) and the relatively nutrient- and chlorophyll-rich Equatorial Pacific (EQP) shows that DCM bacterial assemblage composition is >50% similar throughout all 3 regions. Nonetheless, the SPG, NPG, and EQP assemblages are statistically distinct from each other (ANOSIM, p = 0.001), with the communities of the 2 gyres resembling each other more closely than either resembles the EQP community (which lives geographically between them). Variation in assemblage composition correlates with sea-surface chlorophyll concentration (r2 = 0.71, p < 0.003). This study demonstrates that the DCM horizons of different oceanic regions harbor statistically distinct communities that are consistent within regions for thousands of kilometers.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.35424/RCARTO.I104.1049", "year": 2022, "title": "Space technology applied to patagonian glaciers and their behavior as environmental indicators", "abstract": "This study contemplates a multi-temporal analysis with satellite images and meteorological data from a group of glaciers called Glaciares Escondidos, located to the southwest of the Southern Patagonian Ice Field. Made up of the Dickson, Cubo and Frias glaciers, it has suffered a marked retreat of its fronts that has accelerated in the last 10 years. The Dickson and Frias glaciers were originally fed by a single ice stream and used to act as natural dams, preventing the flow of water between Lake Frias and Lake Dickson. Due to the loss of mass and the retreat of its fronts, the waters that traveled more than 250 km, completely crossing the arid plain of Patagonia to empty into the Atlantic Ocean, today they do it towards the Pacific Ocean sailing the waters of the Chilean fjords that flow towards the west. Formations of proglacial lakes, an increase in the speed of retreat and a high speed of ice flow are observed, which were estimated with multi-temporal measurements and the offset tracking technique with radar images. Likewise, analyzes of mass balances on these three glaciers of the last 20 years are presented, using the geodesic method.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.18848/1835-7156/CGP/V14I01/165-180", "year": 2021, "title": "Adaptations toward Climate Risk: Challenges and Opportunities of the Upland Farmers in Ifugao, Philippines", "abstract": "There has been an increasing concern over the threats posed by climate change to the conservation of UNESCO World Heritage Sites and Globally Important Agricultural Heritage Systems (GIAHS). However, the Ifugao Rice Terraces (IRT) have received limited attention with respect to climate change, considering it is one of the provinces in the Philippines highly at risk to temperature change, projected rainfall change, and combined climate and weather-related risks. It is therefore necessary to assess how the community perceives climate change and how they can cope up with these impacts. This study aimed to explore farmers perceptions, adaptation strategies, and barriers to climate change in the community of Batad Rice Terraces. A total of 114 out of 197 households, three focused group discussions, and five interviews with key stakeholders, including government officials and community leaders, were conducted in 2017 and 2018. The result showed that farmers have already observed the negative impacts of changing weather patterns, particularly in their agricultural production. The most common impacts observed were low rice yield, drought, and drying of rice plants due to unpredictable rainfall patterns and temperature increase. The top three most important adaptation strategies in the face of climate variability are all water-related. This shows that strong local government support is recommended to repair and maintain irrigation canals within the terraces. The salient climate change barriers identified by the farmers were access to climate information, inadequate farm labor, and lack of access to agricultural extension.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.20937/ATM.52824", "year": 2020, "title": "Seasonal trend analysis of carbon dioxide across latitudes of Africa, Europe and Asia", "abstract": "Carbon-driven emissions are on the rise and much work remains to be done to benchmark seasonal carbon increase and ensure its prompt reduction. There is a great need of new methods for validating seasonal trends of carbon dioxide (CO2). We obtained CO2, temperature and normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument onboard the Terra satellite from 2003 to 2008 over Africa (Nigeria, Mauritania, Congo, Sudan), Europe (France, Finland, Turkey, Ukraine), and Asia (China, Mongolia, India, Afghanistan). For the first time, seasonal index analysis was used to validate vegetation index. The seasonality in carbon dioxide was determined dividing the monthly average by the annual mean. Additionally, the percentage difference correlation of the NDVI and CO2 relationship was calculated to investigate the underlying influence of both parameters and validate the seasonal change resulting from the solar activity cycle. By grouping years based on solar activity maximum (2003-2004), intermediate (2005-2006) and very low activity (2007-2008), the results expanded the physical interpretation that seasonal fluctuation of NDVI corresponds to the terrestrial sink of regional CO2, mostly occurring during equinoctial months. Our results demonstrate that seasonal variation of CO2 depends on geographic latitude and the solar activity cycle. This result is essential in studying the future trend relationship between NDVI and CO2.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.DSR.2017.02.002", "year": 2017, "title": "Deepsea fluxes of barium and lithogenic trace elements in the subtropical northeast Atlantic", "abstract": "Total particle flux, Barium and lithogenic trace element fluxes were measured at the mooring Kiel 276 (33N, 22W) in the deepsea of the subtropical Northeast Atlantic. The particulate material was collected between 2002 and 2008 with a sediment trap in 2000m depth and analyzed with ICP-OES/-MS to determine its geochemical composition. The particle flux is controlled by primary production, lithogenic particle inputs via atmospheric transport and the migration of the Azores Front. We used refractory trace elements (eg. Ti, Zr, and the rare earth elements) to demonstrate the changes in flux and composition of the material due to lithogenic inputs. Shortly after periods of high dust load and enhanced primary production an increase in lithogenic trace element fluxes occurred. Especially the formation of aggregates with biogenic matter seems to have a major impact on the downwards transport of lithogenic particles. The observation of particulate Ba is of great interest since it is known as a proxy for past and present primary production. Ba fluxes ranging between 0.02mgm2d1 and 1.21mgm2d1 with biogenic proportions up to 97%. The fluxes of particulate Barium in the water column are mainly attributed to the strength of primary production.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1175/JHM-D-14-0024.1", "year": 2015, "title": "Comparison of TMPA-3B42 Versions 6 and 7 Precipitation Products with Gauge-Based Data over India for the Southwest Monsoon Period", "abstract": "The upgraded version 7 (V7) of the Tropical Rainfall Measuring Mission (TRMM) Multisatellite Precipitation Analysis (TMPA) products is available to the user community. In this paper, two successive versions of the TMPA-3B42 research monitoring product, version 6 (V6) and V7, at the daily scale are evaluated over India during the southwest monsoon with gauge-based data for a 13-yr (19982010) period. Over typical monsoon rainfall zones, biases are improved by 5%10% in V7 over the regions of higher rainfall like the west coast, northeastern, and central India. A similar reduced bias is seen in V7 over the rain-shadow region located in southeastern India. In terms of correlation, anomaly correlation, and RMSE, a marginal improvement is seen in V7. Additionally, in all-India summer monsoon rainfall amounts, mean, interannual values, and standard deviation show an overall improvement in V7. Different skill metrics over typical subregions within India show an improvement of the monsoon rainfall representation in V7. Rainfall frequency in different categories also indicates an overall improvement in V7 across all scales and subregions. Over central India regions associated with the monsoon transients, the sign of the bias has changed toward a positive bias. Even if the bias in the frequency of the occurrence of light rain has improved in V7, the values still show a large difference compared to observations. Though both V6 and V7 are able to represent the anomalous dry/wet regions during contrasting monsoon years, V7 shows some improvement in amplitude of those anomalies over V6. In general, V7 has considerably improved over V6 and will continue to be in demand from various sectors of observed rainfall data users.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSENV.2014.07.063", "year": 2014, "title": "New atmospheric composition observations in the Karakorum region: Influence of local emissions and large-scale circulation during a summer field campaign", "abstract": "In this work we provide an overview of short lived climate forcers (SLCFs) and carbon dioxide variability in the Karakorum, by presenting results deriving from a field campaign carried out at Askole (3015 m a.s.l., Pakistan Northern Areas), by Baltoro glacier. By using an innovative embedded and transportable system, continuous measurements of aerosol particle number concentration (Np, 1571 2670 cm3), surface ozone (O3, 31.7 10.4 nmol/mol), carbon dioxide (CO2, 394.3 6.9 mol/mol) and meteorological parameters have been performed from August 20th to November 10th 2012. The domestic combustion from the Askole village emerged as a possible systematic source of contamination in the valley, with short-lasting pollution events probably related to domestic cooking activities characterized by high values of Np (6066 5903 cm3). By excluding these local contamination events, mountain thermal wind regime dominated the diurnal variability of Np, O3 and CO2. In comparison to night-time, we observed higher Np (+354 cm3) and O3 (+7 nmol/mol) but lower CO2 (8 mol/mol) in air-masses coming from the lower valley during the central part of the day. Part of the day-to-day atmospheric composition variability can be also ascribed to synoptic circulation variability, as observed by using HYSPLIT 5-day back-trajectories.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2014.02.027", "year": 2014, "title": "Uncertainty and variability in satellite-based water vapor column, aerosol optical depth and Angstrom exponent, and its effect on radiative transfer simulations in the Iberian Peninsula", "abstract": "The water vapor column product from the MODIS instrument onboard the Terra satellite is compared with ground-based measurements at six Spanish locations (AERONET stations) in the Iberian Peninsula. In addition, aerosol optical depth (AOD) at 443 nm and at 675 nm retrievals from the MISR instrument onboard the Terra satellite is also compared with ground-based measurements at the same locations to determine their uncertainties. Remote sensing data of water vapor and aerosol optical properties are averaged each month to obtain climatology tables and to characterize atmospheric properties at nine locations in the Iberian Peninsula. These tables are used as input in a radiative transfer model to calculate total shortwave (SW) and ultraviolet erythemal (UVER) irradiance at the nine locations. SW and UVER simulations are recalculated considering the uncertainties and the climatological variability of the input datasets. AOD uncertainty provides changes lower than 6% in most cases for both SW and UVER simulations. The propagation of water vapor uncertainty causes variations in SW simulations less than 4% for solar zenith angles below 75.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.AEOLIA.2014.10.003", "year": 2015, "title": "Dust-storm dynamics over Sistan region, Iran: Seasonality, transport characteristics and affected areas", "abstract": "The present work examines the seasonality, dust-plume altitudinal variation and affected areas for dust storms originated from the Sistan region, southeastern Iran during the summer (JuneSeptember) months of the period 20012012 synthesizing local meteorological records, satellite observations (TOMS, OMI, METEOSAT, MODIS) and HYSPLIT forward trajectories. Dust-storm days (356 in total) are associated with visibility below 1 km at Zabol, Iran meteorological station with higher frequency and intensity in June and July. Monthly-mean composite maps of TOMS and OMI AI show high (>33.5) values over Sistan and nearby downwind areas. HYSPLIT forward-trajectory analysis at 500 m for air masses originated from Sistan on the dust-storm days shows that they usually follow an anti-clockwise transport direction at elevations usually below 2 km, initially moving southwards and then shifting to east-northeast when they are approaching the Arabian Sea coast. This is the result of the influence of the local topography and formation of thermal low-pressure systems over the arid lands. It is found that in few cases the dust storms from Sistan affect central/south Arabian Sea and India, while they control the aerosol loading over northernmost Arabian Sea. The Infrared Difference Dust Index (IDDI) images, which represent brightness temperature reduction due to dust presence over land, are used at specific periods of persistent dust storms over Sistan, confirming the main pathways of the dust plumes and illustrating the importance of the region as one of the most active dust sources in southwest Asia.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.JHYDROL.2014.01.076", "year": 2014, "title": "Examination of water budget using satellite products over Australia", "abstract": "Large-scale water balance in the Australian continent is examined over an 8-year period (20032010) with three commonly used satellite based water cycle components: precipitation (P) from the Tropical Rainfall Measuring Mission (TRMM), evapotranspiration (ET) from the Moderate Resolution Imaging Spectroradiometer (MODIS), and terrestrial water storage change (S) from the Gravity Recovery and Climate Experiment (GRACE). First we evaluate the water balance using the three products over areas with limited annual streamflow to eliminate the influence of runoff in the analysis. We observe more frequent and better closure and consistency in the water balance from the three components over the central part of Western Australia, where low precipitation, high elevation and low relief exist. The data are more coherent at seasonal and annual scales compared to the monthly scale. Application of the three products in Lake Eyre Basin (an internal drainage system) suggests a maximum 6.2 mm/year groundwater inflow to the basin, which is consistent with the regional groundwater flow direction in the area. This result also indicates that the absolute integrated error of the combination of three products should be smaller than 6.2 mm/year, which is about 2.1% of annual precipitation in the basin. If this relative error is assumed for the whole continent, water balance calculation using the three products over the whole Australian continent results in 144.7 11.3 mm/year estimated total runoff to the surrounding oceans during the study period. We found that this estimate is comparable to the estimates of 50150 mm/year from the Australian Bureau of Meteorology and National Water Commission.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JASTP.2012.12.012", "year": 2013, "title": "A comparison of Microtops II and satellite ozone measurements in the period 20012011", "abstract": "Daily average total ozone Microtops measurements obtained during several campaigns conducted from 2001 to 2011 at latitudes from 31 to 68N and in different seasons are compared with satellite observations. The Microtops ozone is derived using different wavelength combinations (Channel I, 305.5/312.5 nm; Channel II, 312.5/320 nm; and Channel III, 305.5/312.5/320 nm). Satellite data from TOMS, OMI, GOME, and GOME-2 are used in the comparison. The three Microtops channels show a high correlation with the satellite retrievals. Channel I shows the best results and produces a mean bias deviation (MBD) less than 2.14% with respect to TOMS, OMI and GOME. The MBD increases to 3% in the comparison against GOME-2, due to the small number of available data. In addition, the total ozone content provided by Channel I displays the more stable behavior during the ten-year period. The Channel III total ozone shows MBD values smaller than those observed for Channel I. However the Channels II and III present a larger variability and show a larger spread of the data. Consequently, Channel I appears as the best option for long term measurements with Microtops.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.GLOPLACHA.2013.10.004", "year": 2013, "title": "Long-term changes in the radiative effects of aerosols and clouds in a mid-latitude region (19852010)", "abstract": "As clouds and aerosols are the main sources of uncertainty in the determination of the energy balance of the Earth, there is a growing interest in the evaluation of their radiative effects. Hence, in this work, long-term data of shortwave radiation from 13 locations over Spain (South-Western Europe) are used to investigate, for the first time, the radiative effects of clouds and aerosols in the period 19852010. In particular, monthly radiation data from ground-based observations and radiative transfer simulations fed with reanalysis data of ozone, water vapour and surface albedo, are used to evaluate the cloud and aerosol radiative effect (CARE). Annual values of the CARE become less negative from Northern to Southern stations. For instance, the annual CARE values for Bilbao (North), Valladolid (Centre), and Murcia (South) are 82, 46, and 42 Wm 2, respectively. CARE averages exhibit a clear seasonal pattern with the strongest contribution during spring and summer months. Particularly in these seasons, there is a very high correlation between CARE values and sunshine duration, number of cloud-free days, and temperature. Additionally, a significant decrease of the radiative effects of the clouds and aerosols is observed over Spain in the last 26 years. Overall, the linear trend of the mean annual CARE series over Spain is statistically significant with positive sign, 3.1 Wm 2 per decade. The significant trend values at individual stations range between 2.9 and 5.2 Wm 2 per decade. Seasonal trends in summer and spring are larger than in autumn and winter. Finally, the radiative effects of water vapour and ozone were also evaluated showing an annual mean over Spain of about 10 Wm 2 and 1 Wm 2, respectively. However, no significant trends were observed for these two variables between 1985 and 2010.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.EJRS.2013.04.003", "year": 2013, "title": "Monthly distribution of diurnal total column ozone based on the 2011 satellite data in Peninsular Malaysia", "abstract": "Ozone (O3) is a radiatively active trace gas, and naturally present in our atmosphere, that plays a prominent role in atmosphere heating rates due to its good capability to absorb the infrared radiation. O3 occurs both naturally in the Earths upper atmosphere and at the ground level. As we breathe the air on Earth, O3 causes damage to the lung tissue and plants as it is an injurious pollutant; it is a major constituent of smog. The atmospheric O3 observations can only be made on global and continental scales by remote sensing instruments situated in the space. The satellite-borne sensor, namely the Atmospheric Infrared Sounder (AIRS) included on the EOS Aqua satellite, was employed to investigate the spatial and temporal variations of diurnal total column Ozone burden over Peninsular Malaysia for the year 2011. The analysis of O3 above five dispersed stations in the study area shows the seasonal variation in the O3 fluctuated considerably observed between NEM and SWM seasons. The mean and the standard deviation of monthly O3 was 244.7 26.8 DU for the entire period, and O3 values strongly correlated with weather conditions. The highest O3 values occurred over industrial and congested urban zones (271.5 DU) on May at Johor. The lowest O3 values were observed during NEM in the pristine coastal environment on December at Kuantan (217 DU; at 3.45N, 103.20E). The O3 has an inverse relationship with the rain and positive with temperature. The monthly O3 maps were obtained from the NASA-operated Giovanni portal (http://disc.sci.gsfc.nasa.gov/giovanni). The AIRS data and the satellite measurements are able to measure the increase of the atmosphere O3 concentrations over different areas.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5094/APR.2015.030", "year": 2015, "title": "Spatio-temporal distribution of absorbing aerosols over Pakistan retrieved from OMI onboard Aura satellite", "abstract": "The observations of aerosol index (AI) deduced from Ozone Monitoring Instrument (OMI) with spatial resolution of 0.25x0.25 have been analyzed over Pakistan from December 2004 to November 2008. Significant spatiotemporal variabilities in AI values were observed with higher values in southern parts and lower values in northern parts of Pakistan. The mean annual AI in Southern and Northern Pakistan have been found to be 1.2200.250 and 1.0880.280, respectively with an overall mean of 1.1550.257 over the entire country. The monthly spatially averaged values of AI show a clear maximum in the month of May (1.5390.499), one of the two months having highest dust storm activity in the region, and minimum value in the month of December (0.8510.134), having lowest dust storm activity. We have also examined the effect of precipitation on AI values and have found that inverse correlation exists between AI and accumulated precipitation, particularly in the months of July, August and September with corresponding R2 values of 0.24, 0.25 and 0.33 respectively.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5094/APR.2014.080", "year": 2014, "title": "A study of tropospheric NO2 variability over Pakistan using OMI data", "abstract": "In this study we present an analysis of spatiotemporal variability of monthly averaged Vertical Tropospheric Columns (VTCs) of NO2 over Pakistan using OMI (ozone monitoring instrument) dataset from December 2004 to November 2008. The results have shown significant spatial and temporal variability of NO2 column values over the study region. Four NO2 hotspots and a high density corridor were identified within the study region. The main sources of NO2 emissions in these areas were also investigated. During the study period, an average value of NO2 was observed to be 1.102 0.081 1015 molecules/cm2, with an increasing trend of 3.29% per year. Twin cities of Islamabad/Rawalpindi, Lahore, Dera Ghazi Khan and Karachi have shown positive trends of 44.10%, 23.48%, 31.40%, and 32.32% per year respectively. Karachi has shown the highest and the lowest mean monthly average values of 11.33 1015 molecules/cm2 and 0.98 1015 molecules/cm2 respectively. Air mass trajectories for hotspot regions have been used to track possible longrange transport of NO2.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5322/JESI.2021.30.10.789", "year": 2021, "title": "Characteristics of Extremely High PM 2.5 Episode and Emergency Reduction Measures Plan in Southeastern Region", "abstract": "This study analyzed the characteristics of high PM2.5 episodes that meets the concentration criteria of Emergency Reduction Measures Plan (ERMP) in Busan during the 2015-2020, and compared with those in Seoul. As a first step, the CAPSS-2017 emission data was employed to analyze the emission differences between Busan and Seoul, and pointed out that Busan emission included the dominance of ship emissions (37.7%) among total PM2.5 city emissions, whereas fugitive PM2,5 emission was the highest in Seoul. These emission characteristics are indicating that the controlling action plan should be uniquely applied to cope with ERMP in each region. We selected extremely high PM2.5 episode days that meet the criteria of ERMP levels. In Busan, Ulsan, and Gyeongnam region, 15, 16, and 8 days of extremely high PM2.5 cases were found, respectively, whereas Seoul showed approximately doubling of occurrences with 37 cases. However, the occurrences in summer season indicated big differences between two cities: the proportion of summer-season occurrence was 13-25% in Busan, whereas no single case have occurred in Seoul. This is suggesting the needs of comprehensive summer emission reduction plan with focusing on sulfur reduction to effectively cope with the ERMP levels in summer in the southeastern region, including Busan.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5958/2320-3234.2021.00012.3", "year": 2021, "title": "Soil Erosion Estimation of Palasbari in Northeast India by RUSLE Model", "abstract": "Soil erosion is a serious problem and its estimation at a large scale is an urgent need. This study aims to estimate the annual soil loss in Palasbari town (639 km2) applying the Revised Universal Soil Loss Equation (RUSLE) model on a GIS platform. The study area comprising Palasbari town is located in the state of Assam in Northeast India. The annual soil loss rate varies from 0 to 3779t ha-1 yr-1 and the mean annual rate of soil loss is 42 t ha-1 yr-1. The soil loss values are categorised into four classes of severity i.e. slight, moderate, severe and extreme soil erosion. Based on spatial analysis, it is found that areas with high slope length and steep slope with heavy and high intensity precipitation are more prone to soil erosion. It is concluded that steep slopes, frequent flooding, sandy soil, destruction of vegetation cover are the main causes of soil erosion in the study area.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.18520/CS/V120/I2/360-367", "year": 2021, "title": "Effect Of SARS-CoV-2 Pandemic Induced Lockdown On The Aerosol Loading Over The Coastal State, Goa", "abstract": "The SARS-CoV-2 pandemic resulted in India imposing a nationwide lockdown on 22 March 2020, bringing all human activities to a complete halt. The\ncurrent study focuses on the effect of lockdown on the\nabundance of atmospheric aerosols over Goa. The\nstudy focused on pre-lockdown, lockdown and period\ncorresponding to lockdown in 2019. The AOD spectra\ndepicted a decrease in the anthropogenically derived\nfine mode aerosols during the lockdown compared to\nthe pre-lockdown period. Mean AOD500 for prelockdown and lockdown periods were 0.43 0.19 and\n0.53 0.11 respectively. The higher AOD500 during\nlockdown was due to an increase in naturally derived\ncoarse mode aerosols, which is further confirmed with\nthe lower Angstrom exponent values (1.04 0.11).\nThe mean black carbon mass concentration for the\nrespective periods were 1990.45 470.87 ng m3 and\n1109.71 218.33 ng m3, and the mean atmospheric\nforcing during the respective periods were 25.13 \n5.72 W m2, 27.31 3.71 W m2 and 30.81 5.59 W m2\nrespectively.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.54302/MAUSAM.V72I1.145", "year": 2021, "title": "Dynamics of Amphan Cyclone and associated changes in ocean, land meteorological and atmospheric parameters", "abstract": "The low-pressure system developed in the Bay of Bengal and the Andaman Sea during March-October, often forms tropical cyclones, depending upon the intensity widespread destruction occurs in the areas where landfall takes place along the Indian coastal region. On 20 May, 2020, tropical cyclone Amphan hit the Indian coast at Bakkhali, West Bengal, in the afternoon (1330 IST). On 19 May, 2020, the intensity strengthened into a super cyclonic storm, with a strong wind speed up to 220 km/h. This cyclone affected a large population of India and Bangladesh. More than twenty-two thousand houses were damaged and millions of people were shifted to a safe place and due to the spread of COVID-19, the rescue missions were quite challenging. The cyclone affected most of the eastern states of India, heavy rainfall occurred causing floods along the track of cyclones. Using multi-satellite, ground and Argo floats data, we have analyzed meteorological and atmospheric parameters during May 2020. Our detailed analysis shows pronounced changes in atmospheric (CO mole fraction, total ozone column) and ocean parameters (chlorophyll concentration, dissolved oxygen, salinity, sea surface and sub-surface temperature) before and after the cyclone. Changes in ocean parameters such as caused by the cyclone Amphan along its track and the atmospheric and meteorological parameters change as the cyclone moves over the land.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.9734/PSIJ/2022/V26I5742", "year": 2022, "title": "Validation of Global Solar Radiation Models on a Horizontal Surface in the Climatic Zones of Burkina", "abstract": "The evaluation of the solar deposit is essential for the sizing of photovoltaic systems. This requires the availability of radiation data. In Burkina Faso, weather data doesnt cover all the country. That makes that solar radiation measured are not available for the all country. Theorical methods can help about it. This paper is written to fill the gap of adapted solar models for the country. In this work, an analysis of the results provided by four models for the estimation of hourly values of global radiation on a horizontal plane was made. The radiation data for the year 2017 comes from the Burkina weather forecast. The validation of the models is carried out by a comparison between the radiation measured and that given by the various models provided by MATLAB code. The different models have been validated by several statistical indicators (RMSE and normalized MAE) and graphs for a clear sky. Scoring criteria have been established to assess the relative quality of each model. The models retained for the study are the Bird and Hulstrom model, the Davy and Hay model, the Capderou model and the Liu and Jordan model. Three sites were affected: Ouagadougou, Dori and Gaoua. We found that for some models, there is a good agreement between the measured values and those estimated by some models for the Dori site, while they are not with the values measured for the Ouagadougou and Gaoua sites. In the town of Dori, the most appropriate model for estimating solar radiation is that of Bird and Hulstrom. For the cities of Ouagadougou and Gaoua, the different models are not suitable.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1175/2007JCLI1570.1", "year": 2008, "title": "Assessment of Cloud Cover Characteristics in Satellite Datasets and Reanalysis Products for Greenland", "abstract": "Clouds have an important controlling influence on the radiation balance, and hence surface melting, over the Greenland ice sheet and need to be classified to derive reliable albedo estimates from visible imagery. Little is known, however, about the true cloud cover characteristics for the largest island on Earth, Greenland. Here, an attempt is made to address this knowledge gap by examining cloud characteristics, as determined by three complementary satellites sensors: the Advanced Very High Resolution Radiometer (AVHRR), the Along Track Scanning Radiometer-2 (ATSR-2), and the Moderate Resolution Imaging Spectroradiometer (MODIS). The first provides a multidecadal time series of clouds, albedo, and surface temperature, and is available, in the form of the extended AVHRR Polar Pathfinder dataset (APP-x), as a homogeneous, consistent dataset from 1982 until 2004. APP-x data, however, are also the most challenging to cloud classify over snow-covered terrain, due to the limited spectral capabilities of the instrument. ATSR-2 permits identification and classification using stereophotogrammetric techniques and MODIS has enhanced spectral sampling in the visible and thermal infrared but over more limited time periods. The spatial cloud fractions from the three sensors are compared and show good agreement in terms of both magnitude and spatial pattern. The cloud fractions, and inferred patterns of accumulation, are then assessed from three commonly used reanalysis datasets: NCEPNCAR, the second NCEPDepartment of Energy (DOE) Atmospheric Model Intercomparison Project (AMIP-II), and the 40-yr ECMWF Re-Analysis (ERA-40). Poor agreement between the reanalysis datasets is found. NCEPDOE AMIP-II produces a cloud fraction similar to that observed by the satellites. NCEPNCAR and ERA-40, however, bear little similarity to the cloud fractions derived from the satellite observations. This suggests that they may produce poor accumulation estimates over the ice sheet and poor estimates of radiation balance. Using these reanalysis data to force a mass balance model of the ice sheet, without appropriate downscaling and correction for the substantial biases present, may, therefore, produce substantial errors in surface melt rate estimates.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.6062/JCIS.2008.01.01.0005", "year": 2008, "title": "Combining wavelets and linear spectral mixture model for MODIS satellite sensor time-series analysis", "abstract": "This work presents a methodology that uses digital fraction images derived from Linear Spectral Mixture Model and wavelets transform from MODIS satellite sensor time-series for land cover change analysis. Our approach uses MODIS surface reflectance images acquired from 2000 to 2006 time period. For this study, a test site was selected in the Mato Grosso State, Brazilian Amazonia. This site has shown high deforestation rates in the last years. The samples of land cover classes were collected during four field campaigns (2003, 2004, 2005 and 2006) to be used as ground truth. The linear spectral mixture model was applied to the MODIS surface reflectance images of red surface reflectance band (620-670 nm bandwidth), near infrared surface reflectance band (NIR, 841-876 nm bandwidth) and medium infrared surface reflectance band (MIR, 2105-2155 nm bandwidth). This model generated the vegetation, shade, and soil fraction images. In the next step, the Meyer orthogonal Discrete Wavelets Transform was used for filtering the time-series of MODIS fraction images. The filtered signal was reconstructed excluding high frequencies for each pixel in the fraction images (soil, vegetation, and shade) of the time-series. This computational procedure allows to observe the original signal without clouds and other noises. The results show that wavelets transform can provide a gain in multitemporal analysis and visualization on inter-annual fraction images variability patterns.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1590/S1679-87592008000300007", "year": 2008, "title": "Lobster (Panulirus argus) captures and their relation with environmental variables obtained by orbital sensors for Cuban waters (1997-2005)", "abstract": "Chlorophyll concentrations (Chl a) data obtained from the Sea Viewing Wide Field of View Sensor (SeaWIFS) ocean color monthly images, Sea Surface Temperature (SST) pathfinder data obtained from the Advanced Very High Resolution Radiometer (AVHRR) sensors, and lobster (Panulirus argus) captures at the Cuban shelf were examined in order to analyze their spatial and temporal variability. A cross-correlation analysis was made between the standardized anomalies of the environmental variables (Chl a and SST) and the standardized anomalies of lobster captures for each fishery zones for the period between 1997 and 2005. For the deep waters adjacent to the fishing zones it was not observed a clear Chl a seasonality and on average the lowest values occurred south of the Island. It is with the three years lag that Chl a had the greatest numbers of significant correlation coefficients for almost all fishing zones. However, the cross-correlation coefficients with SST showed higher values with 1,5 year lag at all zones. Since the two environmental variables obtained by satellite sensors (SST and Chl a) influence the lobsters mainly during the planktonic life cycle, the cross-correlation with lobster captures begin to show significant indexes with lags of 1.5 years or more.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1590/S0100-204X2008001000016", "year": 2008, "title": "Study of the spatio-temporal dynamics of the Pantanal biome using MODIS images", "abstract": "The objective of this work was to evaluate multitemporal data, obtained by moderate resolution imaging spectroradiometer (MODIS) sensor, for the study of spatial-temporal dynamics in two subregions of the Pantanal biome. One hundred and thirty nine enhanced vegetation index (EVI) images, from MOD13 vegetation index product, altimetry data from shuttle radar topography mission (SRTM) and tropical rainfall measuring mission (TRMM) precipitation data were used. In order to reduce data dimensionality, MODIS EVI images were sampled based on contour lines spacing of 10 m. The autocorrelation and cluster analysis were used for spatial and temporal evaluation of the samples; and the principal components analysis was applied to all dataset for spatial and temporal analysis. Results showed a spatial and temporal dependence between spectral response and precipitation. The cluster analysis indicated two spatial groups, suggesting the need for the analysis of the entire study area. The principal components analysis allowed to distinguish four behaviors: the areas permanently flooded; nonflooded areas composed by vegetation; flooded areas with higher spectral vegetation response; and riparian vegetation areas.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1175/2008MWR2622.1", "year": 2009, "title": "Dynamics and Predictability of a Heavy Dry-Season Precipitation Event over West AfricaSensitivity Experiments with a Global Model", "abstract": "In January 2002 the Cape Verde region in tropical West Africa was hit by an exceptionally heavy precipitation event. Rain rates of up to 116 mm (48 h)1 caused harmful impacts on the local population. The rainfall was triggered by a series of two upper-level disturbances penetrating from the extratropics to the West African coast. This study investigates the dynamics and predictability of this event on the basis of simulations with the global model Global Model Europe (GME) of the German Weather Service [i.e., Deutscher Wetterdienst (DWD)] initialized by the European Centre for Medium-Range Weather Forecasts (ECMWF) analysis data. Free forecasts satisfactorily reproduce the upper-level disturbances and the precipitation up to a lead time of 7 days. Several sensitivity experiments are conducted to unveil the reasons for this comparably high predictability and to identify dynamical precursors. The relevance of the upper-level wave structure in the extratropics is examined by modifications of the initial conditions using a quasigeostrophic potential vorticity (PV) inversion technique. While a reservoir of high PV over the North Atlantic and a PV ridge over Europe are found to be crucial for the upper-level wave amplification and the rainfall over West Africa, latent heating over the North Atlantic affects the event rather little in contrast to previous case studies. Surface properties like orography and sea surface temperature anomalies modify the precipitation quantity, but appear not to be essential for the occurrence of the extreme event on the simulated time scale.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/2009JCLI2738.1", "year": 2009, "title": "Numerical Simulations of the Impacts of the Saharan Air Layer on Atlantic Tropical Cyclone Development", "abstract": "In this study, the role of the Saharan air layer (SAL) is investigated in the development and intensification of tropical cyclones (TCs) via modifying environmental stability and moisture, using multisensor satellite data, long-term TC track and intensity records, dust data, and numerical simulations with a state-of-the-art Weather Research and Forecasting model (WRF). The long-term relationship between dust and Atlantic TC activity shows that dust aerosols are negatively associated with hurricane activity in the Atlantic basin, especially with the major hurricanes in the western Atlantic region. Numerical simulations with the WRF for specific cases during the NASA African Monsoon Multidisciplinary Analyses (NAMMA) experiment show that, when vertical temperature and humidity profiles from the Atmospheric Infrared Sounder (AIRS) were assimilated into the model, detailed features of the warm and dry SAL, including the entrainment of dry air wrapping around the developing vortex, are well simulated. Active tropical disturbances are found along the southern edge of the SAL. The simulations show an example where the dry and warm air of the SAL intruded into the core of a developing cyclone, suppressing convection and causing a spin down of the vortical circulation. The cyclone eventually weakened.\n\nTo separate the contributions from the warm temperature and dry air associated with the SAL, two additional simulations were performed, one assimilating only AIRS temperature information (AIRST) and one assimilating only AIRS humidity information (AIRSH) while keeping all other conditions the same. The AIRST experiments show almost the same simulations as the full AIRS assimilation experiments, whereas the AIRSH is close to the non-AIRS simulation. This is likely due to the thermal structure of the SAL leading to low-level temperature inversion and increased stability and vertical wind shear. These analyses suggest that dry air entrainment and the enhanced vertical wind shear may play the direct roles in leading to the TC suppression. On the other hand, the warm SAL temperature may play the indirect effects by enhancing vertical wind shear; increasing evaporative cooling; and initiating mesoscale downdrafts, which bring dry air from the upper troposphere to the lower levels.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/2009WAF2222221.1", "year": 2009, "title": "Prediction of Dry-Season Precipitation in Tropical West Africa and Its Relation to Forcing from the Extratropics", "abstract": "Precipitation during the boreal winter dry season in tropical West Africa is rare but occasionally results in significant impacts on the local population. The dynamics and predictability of this phenomenon have been studied very little. Here, a statistical evaluation of the climatology, dynamics, and predictions of dry-season wet events is presented for the region 7.515N, 10W10E. The analysis is based upon Global Precipitation Climatology Project (GPCP) merged satellitegauge pentad rainfall estimates and 5-day 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) precipitation forecasts, and covers the 23 dry seasons (NovemberFebruary) during 1979/802001/02. Wet events are defined as pentads with an area-averaged precipitation anomaly of more than +200% with respect to the mean seasonal cycle. Composites of the 43 identified events indicate an association with a trough over northwestern Africa, a tropical plume on its eastern side, unusual precipitation at the northern and western fringes of the Sahara, and reduced surface pressure over the Sahara, which allows an inflow of moist southerlies from the Gulf of Guinea to feed the unusual dry-season rainfalls. The results give evidence for a preconditioning by another disturbance about 1 week prior to the precipitation event. The ERA-40 forecasts show a high temporal correlation with observations, a general wet bias, but a somewhat too low number of wet events. With 53% of all identified events correctly forecasted and only 32% of forecasted events not verified, the model shows moderate skill in contrast to the prediction of many other tropical precipitation systems. A separate consideration of hits, misses, and false alarms corroborates the previously proposed hypothesis that a strong extratropical influence enhances the quality of predictions in this region. The results should encourage weather services in West Africa to take advantage of available dry-season precipitation forecasts in terms of the dissemination of early warnings.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/2009JCLI3333.1", "year": 2010, "title": "A Lagrangian Climatology of Tropical Moisture Exports to the Northern Hemispheric Extratropics", "abstract": "Case studies have shown that heavy precipitation events and rapid cyclogenesis in the extratropics can be fueled by moist and warm tropical air masses. Often the tropical moisture export (TME) occurs through a longitudinally confined region in the subtropics. Here a comprehensive climatological analysis of TME is constructed on the basis of seven-day forward trajectories started daily from the tropical lower troposphere using 6-hourly 40-yr ECMWF Re-Analysis (ERA-40) data from the 23-year period 19792001. The objective TME identification procedure retains only those trajectories that reach a water vapor flux of at least 100 g kg1 m s1 somewhere north of 35N. The results show four distinct activity maxima with different seasonal behavior: (i) The pineapple express, which connects tropical moisture sources near Hawaii with precipitation near the North American west coast, has a marked activity maximum in boreal winter. (ii) TME over the west Pacific is largest in summer, partly related to the East Asian monsoon and the mei-yubaiu front. This region alone is responsible for a large portion of TME across 35N. (iii) The narrow activity maximum over the Great Plains of North America is rooted over the Gulf of Mexico and the Caribbean Sea and has a clear maximum in summer and spring. (iv) TME over the western North Atlantic shows the smallest annual cycle with a maximum in winter and autumn. The interannual variability of (i) and (iv) is significantly modulated by El Nino. Over the AfricanEuropeanAsian region, high orographic barriers impede TME. A typical TME trajectory evolution is poleward and quasi-horizontal in the subtropics and then more eastward and upward in the southern midlatitudes, where TME contributes up to 60% to climatological precipitation. The TME dataset presented here can serve as a basis for future studies on extreme events.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/2010JAMC2430.1", "year": 2010, "title": "A Simple Technique for Creating Regional Composites of Sea Surface Temperature from MODIS for Use in Operational Mesoscale NWP", "abstract": "This paper describes a simple technique for creating regional, high-resolution, daytime and nighttime composites of sea surface temperature (SST) for use in operational numerical weather prediction (NWP). The composites are based on observations from NASAs Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Aqua and Terra. The data used typically are available nearly in real time, are applicable anywhere on the globe, and are capable of roughly representing the diurnal cycle in SST. The composites resolution is much higher than that of many other standard SST products used for operational NWP, including the low- and high-resolution Real-Time Global (RTG) analyses. The difference in resolution is key because several studies have shown that highly resolved SSTs are important for driving the airsea interactions that shape patterns of static stability, vertical and horizontal wind shear, and divergence in the planetary boundary layer. The MODIS-based composites are compared to in situ observations from buoys and other platforms operated by the National Data Buoy Center (NDBC) off the coasts of New England, the mid-Atlantic, and Florida. Mean differences, mean absolute differences, and root-mean-square differences between the composites and the NDBC observations are all within tenths of a degree of those calculated between RTG analyses and the NDBC observations. This is true whether or not one accounts for the mean offset between the skin temperatures of the MODIS dataset and the bulk temperatures of the NDBC observations and RTG analyses. Near the coast, the MODIS-based composites tend to agree more with NDBC observations than do the RTG analyses. The opposite is true away from the coast. All of these differences in point-wise comparisons among the SST datasets are small compared to the 1.0C accuracy of the NDBC SST sensors. Because skin-temperature variations from land to water so strongly affect the development and life cycle of the sea breeze, this phenomenon was chosen for demonstrating the use of the MODIS-based composite in an NWP model. A simulated sea breeze in the vicinity of New York City and Long Island shows a small, net, but far from universal improvement when MODIS-based composites are used in place of RTG analyses. The timing of the sea breezes arrival is more accurate at some stations, and the near-surface temperature, wind, and humidity within the breeze are more realistic.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/2010JAMC2485.1", "year": 2010, "title": "African Dust over the Northern Tropical Atlantic: 19552008", "abstract": "African dust outbreaks are the result of complex interactions between the land, atmosphere, and oceans, and only recently has a large body of work begun to emerge that aims to understand the controls onand impacts ofAfrican dust. At the same time, long-term records of dust outbreaks are either inferred from visibility data from weather stations or confined to a few in situ observational sites. Satellites provide the best opportunity for studying the large-scale characteristics of dust storms, but reliable records of dust are generally on the scale of a decade or less. Here the authors develop a simple model for using modern and historical data from meteorological satellites, in conjunction with a proxy record for atmospheric dust, to extend satellite-retrieved dust optical depth over the northern tropical Atlantic Ocean from 1955 to 2008. The resultant 54-yr record of dust has a spatial resolution of 1 and a monthly temporal resolution. From analysis of the historical dust data, monthly tropical northern Atlantic dust cover is bimodal, has a strong annual cycle, peaked in the early 1980s, and shows minimums in dustiness during the beginning and end of the record. These dust optical depth estimates are used to calculate radiative forcing and heating rates from the surface through the top of the atmosphere over the last half century. Radiative transfer simulations show a large net negative dust forcing from the surface through the top of the atmosphere, also with a distinct annual cycle, and mean tropical Atlantic monthly values of the surface forcing range from 3 to 9 W m2. Since the surface forcing is roughly a factor of 3 larger in magnitude than the top-of-the-atmosphere forcing, there is also a positive heating rate of the midtroposphere by dust.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.EARSCIREV.2014.11.001", "year": 2015, "title": "Aerosol remote sensing in polar regions", "abstract": "Multi-year sets of ground-based sun-photometer measurements conducted at 12 Arctic sites and 9 Antarctic sites were examined to determine daily mean values of aerosol optical thickness () at visible and near-infrared wavelengths, from which best-fit values of Angstrom's exponent were calculated. Analysing these data, the monthly mean values of (0.50 m) and and the relative frequency histograms of the daily mean values of both parameters were determined for winterspring and summerautumn in the Arctic and for austral summer in Antarctica. The Arctic and Antarctic covariance plots of the seasonal median values of versus (0.50 m) showed: (i) a considerable increase in (0.50 m) for the Arctic aerosol from summer to winterspring, without marked changes in ; and (ii) a marked increase in (0.50 m) passing from the Antarctic Plateau to coastal sites, whereas decreased considerably due to the larger fraction of sea-salt aerosol. Good agreement was found when comparing ground-based sun-photometer measurements of () and at Arctic and Antarctic coastal sites with Microtops measurements conducted during numerous AERONET/MAN cruises from 2006 to 2013 in three Arctic Ocean sectors and in coastal and off-shore regions of the Southern Atlantic, Pacific, and Indian Oceans, and the Antarctic Peninsula.\n\nLidar measurements were also examined to characterise vertical profiles of the aerosol backscattering coefficient measured throughout the year at Ny-Alesund. Satellite-based MODIS, MISR, and AATSR retrievals of () over large parts of the oceanic polar regions during spring and summer were in close agreement with ship-borne and coastal ground-based sun-photometer measurements. An overview of the chemical composition of mode particles is also presented, based on in-situ measurements at Arctic and Antarctic sites. Fourteen log-normal aerosol number size-distributions were defined to represent the average features of nuclei, accumulation and coarse mode particles for Arctic haze, summer background aerosol, Asian dust and boreal forest fire smoke, and for various background austral summer aerosol types at coastal and high-altitude Antarctic sites. The main columnar aerosol optical characteristics were determined for all 14 particle modes, based on in-situ measurements of the scattering and absorption coefficients. Diurnally averaged direct aerosol-induced radiative forcing and efficiency were calculated for a set of multimodal aerosol extinction models, using various Bidirectional Reflectance Distribution Function models over vegetation-covered, oceanic and snow-covered surfaces. These gave a reliable measure of the pronounced effects of aerosols on the radiation balance of the surfaceatmosphere system over polar regions.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.2110/PALO.2010.P10-151R", "year": 2011, "title": "An improved understanding of the Alaska Coastal Current: The application of a bivalve growth-temperature model to reconstruct freshwater-influenced paleoenvironments", "abstract": "Shells of intertidal bivalve mollusks contain sub-seasonally to interannually resolved records of temperature and salinity variations in coastal settings. Such data are essential to understand changing land-sea interactions through time, specifically atmospheric (precipitation rate, glacial meltwater, river discharge) and oceanographic circulation patterns; however, independent temperature and salinity proxies are currently not available. We established a model for reconstructing daily water temperatures with an average standard error of ,1.3 6C based on variations in the width of lunar daily growth increments of Saxidomus gigantea from southwestern Alaska, United States. Temperature explains 70% of the variability in shell growth. When used in conjunction with stable oxygen isotope data, this approach can also be used to identify changes in past seawater salinity. This study provides a better understanding of the hydrological changes related to the Alaska Coastal Current (ACC). In combination with d18Oshell values, increment-derived temperatures were used to estimate salinity changes with an average error of 1.4 1.1 PSU. Our model was calibrated and tested with modern shells and then applied to archaeological specimens. As derived from the model, the time interval of 9881447 cal yr BP was characterized by ,12 6C colder and much drier (25 PSU) summers. During that time, the ACC was likely flowing much more slowly than at present. In contrast, between 5991014 cal yr BP, the Aleutian low may have been stronger, which resulted in a 3 6C temperature decrease during summers and 12 PSU fresher conditions than today; the ACC was probably flowing more quickly at that time. The shell growthtemperature model can be used to estimate seasonal to interannual salinity and temperature changes in freshwater-influenced environments through time.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSENV.2011.12.027", "year": 2012, "title": "Aerosol optical and radiative properties during summer and winter seasons over Lahore and Karachi", "abstract": "The study of aerosol optical and radiative properties presented here focuses on a geographic region in which there exist significant gaps in our knowledge. These properties have been analyzed through the ground-based Aerosol Robotic Network (AERONET) over the two megacities of Lahore and Karachi for summer (AprilJune) and winter (DecemberFebruary) of 201011. During the study period the monthly mean aerosol optical depth (AOD) at 500 nm over Lahore ranged from 0.57 0.18 to 0.76 0.38, and the monthly mean Angstrom exponent () ranged from 0.39 0.17 to 1.22 0.13. Likewise, over Karachi the monthly mean AOD ranged from 0.33 0.11 to 0.63 0.28 and the values varied between 0.29 0.08 to 0.95 0.22. The average AOD values in summer and winter are 0.66 0.30, 0.50 0.18 and 0.67 0.40, 0.34 0.12 in Lahore and Karachi respectively. The relationship between the Absorption Angstrom Exponent (AAE) and the Extinction Angstrom Exponent (EAE) provided an indication of the relative proportions of urban-industrial and mineral dust aerosols over the two sites. The volume size distributions were higher over Lahore than over Karachi during both seasons. The single scattering albedo (SSA) ranged from 0.83 0.02 (440 nm) to 0.91 0.05 (1020 nm) over Lahore and from 0.88 0.02 (440 nm) to 0.97 0.01 (1020 nm) over Karachi. The lower SSA values over Lahore suggest that absorbing aerosols are more dominant over Lahore than over Karachi. The average aerosol radiative forcing (ARF) values in summer at the surface and the top of atmosphere (TOA) are 101.6 8.2, 63.3 9.5 and 19 4.35, 20 3.1 over Lahore and Karachi respectively. Likewise, the average ARF values in winter at the surface and TOA are 90.3 21.03, 57 6.35 and 26 7, 16 2.3 over Lahore and Karachi respectively. The averaged aerosol ARF values over Lahore and Karachi for the entire period covered by the observations were 22.5 5.9 W m2 and 18 2.2 W m2 at the TOA and 96 13 W m2 and 60 6.8 W m2 at the surface, respectively, giving an averaged atmospheric forcing of 74.56 16.8 W m2 over Lahore and 41.85 6.4 W m2 over Karachi, which indicates significant heating of the atmosphere at both sites. The average heating rate during summer was 2.3 0.1 and 1.2 0.2 K day1 and during winter was 1.8 0.4 and 1.1 0.1 K day1 over Lahore and Karachi respectively.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2009JD012390", "year": 2010, "title": "Dust emission and transport associated with a Saharan depression: February 2007 case", "abstract": "The dust activity over North Africa associated with the Saharan depression event in February 2007 is investigated by mean of spaceborne observations, ground-based measurements, and mesoscale simulation with Meso-NH. The main characteristics of the cyclone as well as the meteorological conditions during this event are described using the European Centre for Medium-Range Weather Forecasts (ECMWF). The dust storm and cloud cover over North Africa is thoroughly described combining for the first time Spinning Enhanced Visible and Infra-Red Imager (SEVIRI) images for the spatiotemporal evolution and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat observations for the vertical distribution. The Saharan depression formed over Algeria in the lee of the Atlas Mountains on the afternoon of 20 February in response to midlatitude trough intrusion. It migrated eastward with a speed of 11 m s1 and reached Libya on 22 February before exiting the African continent toward the Mediterranean Sea on 23 February. The horizontal scale of the cyclone at the surface varied between 800 and 1000 km during its lifetime. On the vertical the cyclone extended over 8 km, and a potential vorticity of 2 potential vorticity units (PVU) was reported at its center at 3 km in altitude. The cyclone was characterized by a surface pressure anomaly of about 9 hPa with respect to the environment, a warm front typified at the surface by an increase in surface temperature of 5C, and a sharp cold front characterized by a drop in surface temperature of 8C and an increase in 10 m wind speed of 15 m s1. The cyclone provided dynamical forcing that led to strong near-surface winds and produced a major dust storm over North Africa. The dust was transported all around the cyclone leaving a clear eye at its center and was accompanied by a deep cloud band along the northwestern edge of the cyclone. On the vertical, slanted dust layers were consistently observed during the event over North Africa. Furthermore, the dust was lofted to altitudes as high as 7 km, becoming subject to long-range transport. The model was able to reasonably reproduce the structure, lifetime, and trajectory of the cyclone. Also, comparison with Moderate Resolution Imaging Spectrometer (MODIS) deep blue aerosol optical depths and CALIPSO-CloudSat observations suggests that the model can be reliably used to quantify the dust emissions associated with this event. The mean daily dust loads over the area influenced by the cyclone were simulated to range between 2 and 8 Tg during the lifetime of the Sharav cyclone (i.e., 5 days). This study suggests that dust emissions linked with Saharan cyclones may contribute significantly to the total dust load over West and North Africa observed annually.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1890/ES10-00103.1", "year": 2010, "title": "Diving seabirds share foraging space and time within and among species", "abstract": "Ecological theory predicts that animals with similar foraging strategies should not be able to co-exist without segregating either in space, time or diet. In communities, intra-specific competition is thought to be more intense than the competition among species, because of the lack of niche partitioning between conspecifics. Hence, while different seabird species can overlap in their foraging distribution, intra-specific competition can drive the neighboring populations of the same species to spatial segregation of foraging areas. To investigate ecological segregation within and among species of diving seabirds, we used a multi-species GPS-tracking approach of seabirds of four species on a small island in the Southwest Atlantic. The present study goes beyond previous work by analyzing simultaneous effects of species and colonies. We observed strikingly strong spatial foraging segregation among birds of the same species, breeding in colonies as close as 2 km from each other. Conspecifics from neighboring colonies used foraging places adjacent to their own colony, and there was little or no overlap with birds from the other colony. A zone with increased predator concentration was completely avoided during foraging trips, likely contributing to the spatial segregation. In addition to spatial segregation, we also observed intra-specific differences in other components of foraging behavior, such as time of day, dive depth and diet. These were most likely caused by optimal foraging of individuals in relation to habitat differences on a local scale, leading to a complex pattern of interactions with environmental covariates, in particular foraging daytime, foraging water layer temperature and depth, distance to coast and bathymetric depth of foraging areas. As mechanisms leading to the spatial segregation we propose a combination of optimal foraging and avoidance of predation.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2009JG001031", "year": 2010, "title": "Distribution of dissolved iron in Antarctic sea ice: Spatial, seasonal, and inter-annual variability", "abstract": "Results from recent field studies in Antarctic sea ice show no clear differences in dissolved iron (dFe) concentrations between pack ice sampled in East Antarctica (2.620.5 nmol/L), in the Weddell Sea (0.736.8 nmol/L), and in the Bellingshausen Sea (1.130.2 nmol/L). Dissolved Fe concentrations were also similar in land-fast ice collected in East Antarctica (0.74.3 nmol/L) and in the Ross Sea (1.16.0 nmol/L). In contrast, we observed a remarkable seasonal drawdown of dFe in sea ice for all reported studies. Furthermore, large inter-annual variations in depth-averaged dFe and organic matter concentrations were observed in sea ice collected in the East Antarctic sector between expeditions in late austral winter-spring of 2003 and 2007. Variability in the water column productivity and in the magnitude of the new Fe supply (e.g., upwelling, resuspended shelf sediments) at the time of sea ice formation could explain such differences.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.DSR.2010.08.001", "year": 2010, "title": "Distribution and diversity of open-ocean, near-bottom macroplankton in the western Mediterranean: Analysis at different spatio-temporal scales", "abstract": "We analyzed the distribution, diversity, and composition of western Mediterranean macroplankton (excluding gelatinous taxa) in the water column over depths of ca. 550850m, with special attention to near-bottom (01.5 and ca. 577m above the bottom, mab) levels, and including data from three areas (off the coasts of Catalonia, and to the NW, and SE of Mallorca, Balearic Islands) in the period 19912008. Spatio-temporal changes in macroplankton abundance were evaluated as follows: (i) by seasonal sampling in 2007 off the Catalonian coast, (ii) by comparing Catalonian and Balearic Island slopes, and (iii) by comparing a fixed station on the Catalonian slope (at 550800m depth) at decadal (1991/19922007/2008) time scales. Diversity (in terms of species richness, S) was greater (i) at ca. 577 mab than at 01.5mab, (ii) over the insular slopes of the Balearic Island (around Mallorca) than over the mainland Catalonian slopes, and (iii) in the period 1991/1992 than in 2007, likely related to higher values of the North Atlantic Oscillation (NAO) index in 1991/1992. In most analyses species composition was strongly influenced by the degree of stratification and homogenization of the water column in summerautumn and winterspring respectively and by location (longitude). Changes consisted mainly of higher density of macroplankton (e.g. abundance of the dominant euphausiids Nematoscelis megalops, Meganyctiphanes norvegica and Euphausia krohni and of the fish Cyclothone braueri) between June and October, parallel to an increase in the T and S close to the bottom. This coincided with changes in the flow of Levantine intermediate water (LIW) in the area. Aggregation of adult forms of the dominant species close to the bottom in summerautumn could be favored because summer is the period of highest density of food copepods, mainly Calanus helgolandicus near the bottom off the Catalan slope. The formation of a thermocline in the water column and the reinforcement of the permanent thermohaline front at the shelf-slope break during summer at ca. 400m in the Balearic Basin may also enhance this tendency toward greater aggregation of deep macroplankton under stratified water column conditions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.DSR.2009.12.002", "year": 2010, "title": "Distribution and burial of organic carbon in sediments from the Indian Ocean upwelling region off Java and Sumatra, Indonesia", "abstract": "Sediments were sampled and oxygen profiles of the water column were determined in the Indian Ocean off west and south Indonesia in order to obtain information on the production, transformation, and accumulation of organic matter (OM). The stable carbon isotope composition (13Corg) in combination with C/N ratios depicts the almost exclusively marine origin of sedimentary organic matter in the entire study area. Maximum concentrations of organic carbon (Corg) and nitrogen (N) of 3.0% and 0.31%, respectively, were observed in the northern Mentawai Basin and in the Savu and Lombok basins. Minimum 15N values of 3.7 were measured in the northern Mentawai Basin, whereas they varied around 5.4 at stations outside this region. Minimum bottom water oxygen concentrations of 1.1mLL1, corresponding to an oxygen saturation of 16.1%, indicate reduced ventilation of bottom water in the northern Mentawai Basin. This low bottom water oxygen reduces organic matter decomposition, which is demonstrated by the almost unaltered isotopic composition of nitrogen during early diagenesis. Maximum Corg accumulation rates (CARs) were measured in the Lombok (10.4gCm2yr1) and northern Mentawai basins (5.2gCm2yr1). Upwelling-induced high productivity is responsible for the high CAR off East Java, Lombok, and Savu Basins, while a better OM preservation caused by reduced ventilation contributes to the high CAR observed in the northern Mentawai Basin. The interplay between primary production, remineralisation, and organic carbon burial determines the regional heterogeneity. CAR in the Indian Ocean upwelling region off Indonesia is lower than in the Peru and Chile upwellings, but in the same order of magnitude as in the Arabian Sea, the Benguela, and Gulf of California upwellings, and corresponds to 0.17.1% of the global ocean carbon burial. This demonstrates the relevance of the Indian Ocean margin off Indonesia for the global OM burial.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2009GB003730", "year": 2010, "title": "Dissolved inorganic carbon dynamics and air-sea carbon dioxide fluxes during coccolithophore blooms in the northwest European continental margin (northern Bay of Biscay)", "abstract": "We report a data set of dissolved inorganic carbon (DIC) obtained during three cruises in the northern Bay of Biscay carried out in June 2006, May 2007, and May 2008. During these cruises, blooms of the coccolithophore Emiliania huxleyi occurred, as indicated by patches of high reflectance on remote sensing images, phytoplankton pigment signatures, and microscopic examinations. Total alkalinity showed a nonconservative behavior as a function of salinity due to the cumulative effect of net community calcification (NCC) on seawater carbonate chemistry during bloom development. The cumulative effect of NCC and net community production (NCP) on DIC and the partial pressure of CO2 (pCO2) were evaluated. The decrease of DIC (and increase of pCO2) due to NCC was overwhelmingly lower than the decrease of DIC (and decrease of pCO2) due to NCP (NCC:NCP 1). During the cruises, the northern Bay of Biscay acted as a sink of atmospheric CO2 (on average 9.7 mmol C m2 d1 for the three cruises). The overall effect of NCC in decreasing the CO2 sink during the cruises was low (on average 12% of total air-sea CO2 flux). If this is a general feature in naturally occurring phytoplankton blooms in the North Atlantic Ocean (where blooms of coccolithophores are the most intense and recurrent), and in the global ocean, then the potential feedback on increasing atmospheric CO2 of the projected decrease of pelagic calcification due to thermodynamic CO2 production from calcification is probably minor compared to potential feedbacks related to changes of NCP.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S12237-009-9161-0", "year": 2010, "title": "Diagnostic Properties of Phytoplankton Time Series from Remote Sensing", "abstract": "Remote sensing provides our only window into the phytoplankton community on synoptic scales, permitting the construction of spatially distributed time series of biomass indexed as chlorophyll concentration. Data from the SeaWiFS mission have accumulated to the point where they meet the criterion of a 10-year series. The seasonal phytoplankton cycle is the dominant mode of temporal variability. The time series can be used to construct a variety of ecological indicators of the pelagic system useful in ecosystem-based management. These are reviewed and examples of their implementation are presented. Phenology of phytoplankton blooms is given particular attention. Interannual variation in some of the indicators is strong, presumably a response to variation in large-scale forcing. Examination of the results in the context of a simple phytoplankton-nutrient model enhances the interpretation. Remote sensing imagery also lends itself to the retrieval of information on community structure, in addition to biomass. More information will be recovered from satellite imagery if the remote-sensing program is coupled closely to a ship program on which appropriate bio-optical observations are made. The data series can be distilled to yield concise descriptions of the unfolding of ecosystem characteristics through time.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1659/MRD-JOURNAL-D-12-00066.1", "year": 2012, "title": "Atmospheric Pollution in the Hindu KushHimalaya Region", "abstract": "This paper presents a detailed review of atmospheric pollution observed in the Hindu KushHimalaya (HKH) region and its implications for regional climate. Data from in situ measurements made at high-altitude stations in the HKH region, observations from satellite-based instruments, and global climate modeling study results are discussed. Experimental observations discussed include both atmospheric measurements and data from snow and ice core sampling from different glaciers in the HKH region. The paper focuses on the atmospheric brown cloud loadings over the Himalayas, particularly black carbon (BC) and ozone, which have links to regional climate and air-pollutionrelated impacts. Studies show elevated levels of anthropogenic ozone and BC over the Himalayas during the pre-monsoon season with concentrations sometimes similar to those observed over an average urban environment. The elevated concentration observed over the Himalayas is thought to come from the lowlands, especially the highly populated areas of the Indo-Gangetic Plains. The implications of high BC loading in the Himalayan atmosphere as well as elevated BC deposition on snow and ice surfaces for regional climate, hydrological cycle, and glacial melt are discussed.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2011JC007357", "year": 2012, "title": "Anomalous intraseasonal events in the thermocline ridge region of Southern Tropical Indian Ocean and their regional impacts", "abstract": "The present study explores the mechanisms responsible for the strong intraseasonal cooling events in the Thermocline Ridge region of the southwestern Indian Ocean. Air sea interface and oceanic processes associated with Madden Julian Oscillation are studied using an Ocean General Circulation Model and satellite observations. Sensitivity experiments are designed to understand the ocean response to intraseasonal forcing with a special emphasis on 2002 cooling events, which recorded the strongest intraseasonal perturbations during the last well-observed decade. This event is characterized by anomalous Walker circulation over the tropical Indian Ocean and persistent intraseasonal heat flux anomaly for a longer duration than is typical for similar events (but without any favorable preconditioning of ocean basic state at the interannual timescale). The model heat budget analysis during 1996 to 2007 revealed an in-phase relationship between atmospheric fluxes associated with Madden Julian Oscillation and the subsurface oceanic processes during the intense cooling events of 2002. The strong convection, reduced shortwave radiation and increased evaporation have contributed to the upper ocean heat loss in addition to the slower propagation of active phase of convection, which supported the integration of longer duration of forcing. The sensitivity experiments revealed that dynamic response of ocean through entrainment at the intraseasonal timescale primarily controls the biological response during the event, with oceanic interannual variability playing a secondary role. This study further speculates the role of oceanic intraseasonal variability in the 2002 droughts over Indian subcontinent.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.4314/WSA.V38I4.1", "year": 2012, "title": "An inter-comparison of model-simulated eastwest climate gradients over South Africa", "abstract": "This study examines how the eastwest gradient of climate over South Africa is represented in terms of mean rainfall, tropospheric humidity and circulation, and surface latent heat flux in the satellite era 1980-2001. Inter-comparisons of NCEP2 reanalysis and GPCP satellite-gauge merged rainfall with coupled general circulation model (GCM) simulations from generic CMIP-3 are made, with a focus on the maize belt 25-29S, 25-30E. The summer climatology is analysed for the zonal gradient in vertical atmospheric structure and the annual cycle of rainfall. A wet bias is found in most simulations over the eastern mountains, but in two GCMs (CSM3, PCM) it extends over the western plateau. The east-west gradient in vegetation affects the vertical flux of surface moisture into the atmosphere. ECMWF reanalysis and SAFARI-2000 flux tower data reveal that this process is triggered during daytime heating, so model ability to handle the diurnal cycle is crucial. Inter-annual variability is briefly studied and two operational ensemble models (CFS and ECHAM4) simulate and forecast summer rainfall variations with positive correlation to observed values. The AIRS satellite night and day relative humidity structure is contrasted for dry and wet January months. All five generic CMIP-3 models: GFDL2, CSM3, PCM, HADen, ECHAM4 project a drying trend in the maize area over the period 20002050, using the SRES A1B scenario. Recommendations for observing the surface and mixed layer moisture fluxes are given.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2011JD017370", "year": 2012, "title": "An assessment of the surface longwave direct radiative effect of airborne dust in Zhangye, China, during the Asian Monsoon Years field experiment (2008)", "abstract": "In AprilJune 2008, NASA Goddard's ground-based mobile laboratories (SMART-COMMIT) were deployed to Zhangye China (39.0N; 101W) to support the Asian Monsoon Years field experiment and the East Asian Study of Tropospheric Aerosols and Impact on Regional Climate. One of the primary objectives at Zhangye, a semi-arid region located between the Taklimakan and Gobi Deserts, was to capture and characterize dust aerosols near the source and to quantify their direct radiative effects (DRE). A regional dust optical model was constructed by combining previously measured soil mineralogy data at Zhangye with COMMIT's particle microphysical measurements. During a 2-week period of heightened dust activity, retrieved longwave (LW) aerosol optical thickness () from SMART's Atmospheric Emitted Radiance Interferometer was used in the Fu-Liou radiative transfer model to derive LW instantaneous DRE (DRELW) at the surface, top of atmosphere, and heating rate profiles for cloud-free conditions. Conservatively, surface instantaneous DRELW and LW forcing efficiency range from about 220 Wm2 and 3135 Wm21 (0 0.83), respectively. The significance of DRELWrelative to its shortwave counterpart was estimated to be between 51 and 58%, but of opposite sign, partly compensating shortwave surface cooling. Compared to Saharan dust observed during the NAMMA-2006 field experiment at Cape Verde, dust LW forcing efficiency for this study was found to be a factor of two larger stemming from differences in environmental and surface conditions, aerosol absorption, and Zhangye's close proximity to major desert sources. Relative to observed and modeled ranges in surface DRELW for clouds (3080 Wm2) and greenhouse gases (2 Wm2), this study's upper range in DRELW represents a significant perturbation to the climate system with important implications for better understanding regional changes in surface temperatures and moisture budgets.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2010.549521", "year": 2012, "title": "A case study of the association of total ozone variability with major earthquakes in Greece during 20012010", "abstract": "Recent studies have suggested that variation of the total ozone content may be a precursor tool for earthquake forecasts. The main aim of this analysis is to examine whether the total ozone variability before and after the eight large earthquakes (M w 6.0) of the decade 20012010 in Greece could be related with these earthquake events. The results clearly show that the association of total ozone fluctuation with earthquake occurrence in the time window of 2 weeks before and after each of these large earthquake events is not statistically significant.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.APR.2015.05.002", "year": 2015, "title": "Analysis of optical and physical properties of aerosols during crop residue burning event of October 2010 over Lahore, Pakistan", "abstract": "Aerosols released from biomass burning affect the tropospheric chemistry, radiation budget and cloud processes and hence can cause significant climate modifications. Due to certain economical reasons, the open burning of crop residue has become popular in Pakistan. In the present work we have analyzed the optical and physical properties of aerosols during crop residue burning over Lahore, a central location of Pakistan. The data from ground based Aerosol Robotic Network (AERONET), satellite based MODIS and CALIPSO remote sensing instruments have been used for the characterization of aerosols during crop residue burning event of October 2010. The maximum value (2.75) of daily mean AOD was observed on 20 October 2010 and the next highest value of 2.64 was observed on 19 October 2010, indicating heavy aerosol loading over Lahore on both days due to intense crop residue burning. The fine mode AOD values ranged from 0.14 to 2.68 (on 20 October 2010) with average value of 0.87 during October 2010 over Lahore. It was found that fine mode aerosols have greater contribution than coarse mode aerosols towards total aerosol burden indicating the presence of fine mode (crop residue burning) aerosols over Lahore. Cluster analysis showed that the mixed aerosols (biomass burning and urban-industrial) were present during the heavy aerosol loading period over Lahore. The highest volume concentration of fine mode occurred on 19 and 20 October 2010 representing the dominance of fine mode aerosols. Due to scattering of incoming solar radiation by intense smoke observed on 19 and 20 October 2010 high values of SSA (0.95) were found. HYSPLIT model backward trajectories showed that the winds transported aerosols from southeast and northwest directions.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1002/2014JD022151", "year": 2015, "title": "An improved methodology for deriving high-resolution surface shortwave radiative fluxes from MODIS in the Arctic region", "abstract": "The Arctic is experiencing an unprecedented increase in surface air temperature and decrease in sea ice extent. The causes of these changes are still being debated; radiative fluxes are believed to play an important role in this warming. The primary motivation for this study is to advance the quality and resolution of currently available information on surface shortwave (solar) irradiance (SWR) for the Arctic. Such information is needed to meet the challenge for accurate estimates of heat input into the open waters. An inference scheme that utilizes the Moderate Resolution Imaging Spectroradiometer (MODIS) observations is optimized for high latitudes and implemented at 5 km for 2007 at an hourly time scale. Evaluation of the 5 km based SWR estimates against hourly ground observations at Barrow site shows a mean bias of 7.9 W m2 (3% of mean values), a standard deviation of 58.2 W m2 (23% of mean value), and a high correlation of 0.95. Evaluation of the SWR estimates against daily ground measurements at these latitudes shows good agreement with surface observations at three sites, with a mean bias of 1.9 W m2 (1.1% of mean values), a standard deviation of 31.5 W m2 (17.8% of mean value), and a high correlation of 0.96. Information at this high resolution and good quality can lead to improved estimates of heat input into the complex Arctic domain. For the Beaufort Sea domain (70N80N, 120E50E), the differences can amount to 116 MJ m2 ( 7%) of the total solar input of this region.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/978-3-319-13743-8_9", "year": 2015, "title": "Aerosols and Temperature Rise in the Northwestern Himalaya, India", "abstract": "Aerosols, the important constituents of our atmosphere, indicate a colloidal system of particulate, gaseous and volatile organic compounds. Aerosols play a significant role in affecting adversely the radiative balance of the Earth as well as the air temperature . Moreover, these not only influence the visibility and overall air quality, but also adversely affect health of living organisms in an ecosystem. In this context, the present attempt at Mohal (1,154 m, 77.12E, 31.91N) in the Kullu valley of Himachal Pradesh in the northwestern Himalayan region explains the ever increasing columnar aerosols, their relationship with black carbon (BC) aerosols, impact of local meteorological conditions, long range transport sources and their collective impact on radiative forcing and resultant temperature rise. The aerosol optical depth (AOD) having been under observation for the last half a decade (20062010) shows higher values at shorter wavelengths and lower at longer wavelengths. At a representative wavelength of 500 nm, AOD is found to be increasing at the rate of 1.9 % per annum from 2006 to 2010. Overall, AOD values in all the wavelengths (3801,025 nm) were found between 0.2380.242, reflecting an increasing trend at the rate of 0.84 % per annum. The monthly mean concentration of BC aerosols is noticed maximum with 6,617 ng m3 in January, 2010. The pollution loads in terms of AOD values translate into a temperature rise by ~0.54 K day1. The local as well as transported aerosols together contribute to the existing aerosols in the present study region. The local sources possibly belong to anthropogenic aerosols including vehicular emissions, biomass burning (like fuel wood for cooking), forest fires, open waste burning, etc. While the transported aerosols most probably include fine mineral dust from the desert regions and the sulphate aerosol from the oceanic regions with the movement of air masses prior to the western disturbances and monsoonal winds in the region.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/SREP07680", "year": 2015, "title": "A new tool for predicting drought: An application over India", "abstract": "This is the first attempt of application of atmospheric electricity for rainfall prediction. The atmospheric electrical columnar resistance based on the model calculations involving satellite data has been proposed as a new predictor. It is physically sound, simple to calculate and not probabilistic like the standardized precipitation index. After applying this new predictor over India, it has been found that the data solely over the Bay of Bengal (BB) are sufficient to predict a drought over the country as a whole. Finally, two independent new methods to predict drought conditions and a preliminary forecast of the same for India for year 2014 have been given. Unlike the existing drought prediction techniques, the identification of drought conditions in a pre-drought year during 19811990 and 20012013 over India has been achieved 100% successfully using the suggested new methods. The association between rainfall and this new predictor has also been found on the sub-regional scale. So, the present predictor is expected to get global application and application in climate models. From the analysis, generally, a long period rising trend in aerosol concentration over the BB causes weak monsoon over India but that for a short time i.e. in pre-monsoon period strengthens it.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/NHESS-10-1299-2010", "year": 2010, "title": "Complementary nature of surface and atmospheric parameters associated with Haiti earthquake of 12 January 2010", "abstract": "Abstract. The present paper describes surface (surface air temperature) and atmospheric parameters (relative humidity, surface latent heat flux) over the epicenter (1827 25 N 7231 59 W) of Haiti earthquake of 12 January 2010. Our analysis shows pronounced changes in surface and atmospheric parameters few days prior to the main earthquake event. Changes in relative humidity are found from the surface up to an altitude of 500 hPa clearly show atmospheric perturbations associated with the earthquake event. The purpose of this paper is to show complementary nature of the changes observed in surface, atmospheric and meteorological parameters. The total ozone concentration is found to be lowest on the day of earthquake and afterwards found to be increased within a week of earthquake. The present results show existence of coupling between lithosphere-atmosphere associated with the deadly Haiti earthquake.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1657/1938-4246-42.3.325", "year": 2010, "title": "At-sea Observations of Marine Birds and Their Habitats before and after the 2008 Eruption of Kasatochi Volcano, Alaska", "abstract": "Kasatochi volcano, an island volcano in the Aleutian chain, erupted on 78 August 2008. The resulting ash and pyroclastic flows blanketed the island, covering terrestrial habitats. We surveyed the marine environment surrounding Kasatochi Island in June and July of 2009 to document changes in abundance or distribution of nutrients, fish, and marine birds near the island when compared to patterns observed on earlier surveys conducted in 1996 and 2003. Analysis of SeaWiFS satellite imagery indicated that a large chlorophyll-a anomaly may have been the result of ash fertilization during the eruption. We found no evidence of continuing marine fertilization from terrestrial runoff 10 months after the eruption. At-sea surveys in June 2009 established that the most common species of seabirds at Kasatochi prior to the eruption, namely crested auklets (Aethia cristatella) and least auklets (Aethia pusilla) had returned to Kasatochi in relatively high numbers. Densities from more extensive surveys in July 2009 were compared with pre-eruption densities around Kasatochi and neighboring Ulak and Koniuji islands, but we found no evidence of an eruption effect. Crested and least auklet populations were not significantly reduced by the initial explosion and they returned to attempt breeding in 2009, even though nesting habitat had been rendered unusable. Maps of pre- and post-eruption seabird distribution anomalies indicated considerable variation, but we found no evidence that observed distributions were affected by the 2008 eruption.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACPD-9-12899-2009", "year": 2009, "title": "Trans-Pacific transport of Asian dust and CO: accumulation of biomass burning CO in the subtropics and dipole structure of transport", "abstract": "Abstract. In May 2003, both MODIS aerosol optical depth (AOD) and carbon monoxide (CO) measurements from MOPITT show significant trans-Pacific transport to North America. We apply the global chemical transport model, GEOS-Chem, to analyze the main features of the long-range transport events. Enhancements of MOPITT CO over the tropical Pacific are much broader than MODIS AOD enhancements. We find in model simulations that a substantial fraction of the CO enhancements in the subtropics in May is due to biomass burning in Southeast Asia in April. Biomass burning CO was recirculated into the subtropical high-pressure system and lingered for a much longer period than aerosols transported at higher latitudes. Simulated AOD enhancements are due to a combination of dust, sulfate, and organic and elemental carbons. Dust contribution dominates the AOD enhancements in early May. Model results indicate that dust transport takes place at higher altitude than the other aerosols. MODIS observations indicate a bias in model simulated pathway of dust AOD transport. Sensitivities of dust transport pathways are analyzed in the model. The dipole structure of transport over the Pacific is found to be the key factor leading to the high sensitivity of simulated transport pathways to source location and wind field.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.MARPOLBUL.2009.04.023", "year": 2009, "title": "The effects of wind and rainfall on suspended sediment concentration related to the 2004 Indian Ocean tsunami", "abstract": "The effects of rainfall and wind speed on the dynamics of suspended sediment concentration (SSC), during the 2004 Indian Ocean tsunami, were analyzed using spatial statistical models. The results showed a positive effect of wind speed on SSC, and inconsistent effects (positive and negative) of rainfall on SSC. The effects of wind speed and rainfall on SSC weakened immediately around the tsunami, indicating tsunami-caused floods and earthquake-induced shaking may have suddenly disturbed the oceanatmosphere interaction processes, and thus weakened the effects of wind speed and rainfall on SSC. Wind speed and rainfall increased markedly, and reached their maximum values immediately after the tsunami week. Rainfall at this particular week exceeded twice the average for the same period over the previous 4years. The tsunami-affected airsea interactions may have increased both wind speed and rainfall immediately after the tsunami week, which directly lead to the variations in SSC.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.CHEMGEO.2008.12.013", "year": 2009, "title": "Strontium isotopes and major ion chemistry in the Chambal River system, India: Implications to silicate erosion rates of the Ganga", "abstract": "The dissolved concentrations of major ions and Sr isotopes (87Sr/86Sr) were measured in the headwaters of the Chambal river and its tributaries draining the Deccan Trap basalts and the Vindhyan sediments of peninsular India. The total dissolved solids (TDS) ranged from 181 to 547 mg L1; much higher than the global mean river water. A significant fraction of solute abundance in the Chambal river is derived from sodium salts, unlike the Himalayan rivers which exhibit dominance of (Ca+Mg) salts. It is estimated that the Chambal river supplies about one-third of sodium via the Yamuna to the Ganga at Rajshahi (Bangladesh), with only 6.5% of water discharge. The presence of Na salts not associated with chloride in the Chambal headwaters constraints the application of Na (Na corrected for Cl) as an index of silicate derived component. This finding brings out the need to revisit the estimates of silicate erosion rate (SER) and associated CO2 consumption in the Ganga basin, downstream Allahabad, based on Na as an index. The Sr concentration in the Chambal tributaries varied from 1.9 M to 5.9 M and 87Sr/86Sr ratio from 0.70923 to 0.71219. Unlike the Himalayan Rivers, Sr isotope composition in the Chambal river is far less radiogenic as the major sources of Sr to the Chambal are the Deccan Trap basalts and the Vindhyan sediments, which are low in 87Sr/86Sr. The Sr isotope budget of the Ganga, based on available data of the Chambal, Betwa, Ken, Yamuna and the Ganga shows that, weathering of the Deccan Trap basalts and the Vindhyan sediments (the drainage basin of the Chambal, Betwa and the Ken) contribute 70% of the dissolved Sr to the Ganga at Varanasi. This study highlights the key role of peninsular rivers draining the Deccan and the Vindhyan regions in the major ion and Sr budget of the Ganga.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/9781444305388.CH7", "year": 2009, "title": "Stratospheric Chemistry: Aerosols and the Ozone Layer", "abstract": "This chapter contains sections titled: Introduction General properties of the stratospheric aerosol layer General stratospheric chemistry Heterogeneous stratospheric chemistry Polar stratospheric clouds and the ozone hole Volcanic aerosol Meteoritic aerosol Interactions between stratospheric chemistry and climate References", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/BG-6-2861-2009", "year": 2009, "title": "Spatial distribution of the iron supply to phytoplankton in the Southern Ocean: a model study", "abstract": "Abstract. An upgraded version of the biogeochemical model SWAMCO is coupled to the ocean-sea-ice model NEMO-LIM to explore processes governing the spatial distribution of the iron supply to phytoplankton in the Southern Ocean. The 3-D NEMO-LIM-SWAMCO model is implemented in the ocean domain south of latitude 30 S and runs are performed over September 1989December 2000. Model scenarios include potential iron sources (atmospheric deposition, iceberg calving/melting and continental sediments) as well as iron storage within sea ice, all formulated based on a literature review. When all these processes are included, the simulated iron profiles and phytoplankton bloom distributions show satisfactory agreement with observations. Analyses of simulations and sensitivity tests point to the key role played by continental sediments as a primary source for iron. Iceberg calving and melting contribute by up to 25% of Chl-a simulated in areas influenced by icebergs while atmospheric deposition has little effect at high latitudes. Activating sea ice-ocean iron exchanges redistribute iron geographically. Stored in the ice during winter formation, iron is then transported due to ice motion and is released and made available to phytoplankton during summer melt, in the vicinity of the marginal ice zones. Transient iron storage and transport associated with sea ice dynamics stimulate summer phytoplankton blooming (up to 3 mg Chl-a m-3 in the Weddell Sea and off East Antarctica but not in the Ross, Bellingshausen and Amundsen Seas. This contrasted feature results from the simulated variable content of iron in sea ice and release of melting ice showing higher ice-ocean iron fluxes in the continental shelves of the Weddell and Ross Seas than in the Eastern Weddell Sea and the Bellingshausen-Amundsen Seas. This study confirms that iron sources and transport in the Southern Ocean likely provide important mechanisms in the geographical development of phytoplankton blooms and associated ecosystems.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.4081/GH.2009.221", "year": 2009, "title": "Rift Valley fever in a zone potentially occupied by Aedes vexans in Senegal: dynamics and risk mapping", "abstract": "This paper presents an analysis of the interaction between the various variables associated with Rift Valley fever (RVF) such as the mosquito vector, available hosts and rainfall distribution. To that end, the varying zones potentially occupied by mosquitoes (ZPOM), rainfall events and pond dynamics, and the associated exposure of hosts to the RVF virus by Aedes vexans, were analyzed in the Barkedji area of the Ferlo, Senegal, during the 2003 rainy season. Ponds were identified by remote sensing using a high-resolution SPOT-5 satellite image. Additional data on ponds and rainfall events from the Tropical Rainfall Measuring Mission were combined with in-situ entomological and limnimetric measurements, and the localization of vulnerable ruminant hosts (data derived from QuickBird satellite). Since Ae. vexans productive events are dependent on the timing of rainfall for their embryogenesis (six days without rain are necessary to trigger hatching), the dynamic spatio-temporal distribution of Ae. vexans density was based on the total rainfall amount and pond dynamics. Detailed ZPOM mapping was obtained on a daily basis and combined with aggressiveness temporal profiles. Risks zones, i.e. zones where hazards and vulnerability are combined, are expressed by the percentages of parks where animals are potentially exposed to mosquito bites. This new approach, simply relying upon rainfall distribution evaluated from space, is meant to contribute to the implementation of a new, operational early warning system for RVF based on environmental risks linked to climatic and environmental conditions.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.RSE.2009.04.012", "year": 2009, "title": "Remote sensing of mineral dust over land with MSG infrared channels: A new Bitemporal Mineral Dust Index", "abstract": "A new Bitemporal Mineral Dust Index (BMDI) is derived from Meteosat Second Generation (MSG) infrared observations over land at two different time slots per day. This daily dust index is evaluated with AErosol RObotic NETwork (AERONET) surface observations, MODerate resolution Imaging Spectro-radiometer (MODIS) Deep Blue Aerosol Optical Depth (AOD) and Ozone Monitoring Instrument (OMI) Aerosol Index, showing a good capability of the BMDI for dust detection and dust load estimation over land and also over deserts. BMDI dust detection is shown to be limited in scenes with high atmospheric humidity as e.g. coastal regions. In particular the insensitivity of BMDI to biomass burning aerosol is shown, leading to the possibility of remote sensing of mineral dust also in regions with large contributions of biomass burning aerosol to the total column aerosol concentrations. Time series of mineral dust as inferred from BMDI for the year 2006 are presented for four regions over the Sahara. These time series show strong (and different) annual cycles of dust load for all four regions. Especially the strong episodic character of atmospheric dust in the main source regions can be inferred from BMDI observations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/BG-6-751-2009", "year": 2009, "title": "Quantitative observation of cyanobacteria and diatoms from space using PhytoDOAS on SCIAMACHY data", "abstract": "Abstract. In this study the technique of Differential Optical Absorption Spectroscopy (DOAS) has been adapted for the retrieval of the absorption and biomass of two major phytoplankton groups (PhytoDOAS) from data of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite sensor. SCIAMACHY measures back scattered solar radiation in the UV-Vis-NIR spectral regions with a high spectral resolution (0.2 to 1.5 nm). In order to identify phytoplankton absorption characteristics in the SCIAMACHY data in the range of 430 to 500 nm, phytoplankton absorption spectra measured in-situ during two different RV \"Polarstern\" expeditions were used. The two spectra have been measured in different ocean regions where different phytoplankton groups (cyanobacteria and diatoms) dominated the phytoplankton composition. Results clearly show distinct absorption characteristics of the two phytoplankton groups in the SCIAMACHY spectra. Using these results in addition to calculations of the light penetration depth derived from DOAS retrievals of the inelastic scattering (developed by Vountas et al., 2007), globally distributed pigment concentrations for these characteristic phytoplankton groups for two monthly periods (FebruaryMarch 2004 and OctoberNovember 2005) were determined. This satellite information on cyanobacteria and diatoms distribution clearly matches the concentrations based on high pressure liquid chromatography (HPLC) pigment analysis of collocated water samples and concentrations derived from a global model analysis with the NASA Ocean Biogeochemical Model (Gregg et al., 2003; Gregg and Casey 2007). The quantitative assessment of the distribution of key phytoplankton groups from space enables various biogeochemical regions to be distinguished and will be of great importance for the global modeling of marine ecosystems and biogeochemical cycles which enables the impact of climate change in the oceanic biosphere to be estimated.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.CSR.2009.03.008", "year": 2009, "title": "New insights into the spatial variability of the surface water carbon dioxide in varying sea ice conditions in the Arctic Ocean", "abstract": "In the summer of 2005, continuous surface water measurements of fugacity of CO2 (fCO2sw), salinity and temperature were performed onboard the IB Oden along the Northwest Passage from Cape Farwell (South Greenland) to the Chukchi Sea. The aim was to investigate the importance of sea ice and river runoff on the spatial variability of fCO2 and the seaair CO2 fluxes in the Arctic Ocean. Additional data was obtained from measurements of total alkalinity (AT) by discrete surface water and water column sampling in the Canadian Arctic Archipelago (CAA), on the Mackenzie shelf, and in the Bering Strait. The linear relationship between AT and salinity was used to evaluate and calculate the relative fractions of sea ice melt water and river runoff along the cruise track. High-frequency fCO2sw data showed rapid changes, due to variable sea ice conditions, freshwater addition, physical upwelling and biological processes. The fCO2sw varied between 102 and 678atm. Under the sea ice in the CAA and the northern Chukchi Sea, fCO2sw were largely CO2 undersaturated of approximately 100atm lower than the atmospheric level. This suggested CO2 uptake by biological production and limited seaair CO2 gas exchange due to the ice cover. In open areas, such as the relatively fresh water of the Mackenzie shelf and the Bering Strait, the fCO2sw values were close to the atmospheric CO2 level. Upwelling of saline and relatively warm water at the Cape Bathurst caused a dramatic fCO2sw increase of about 100atm relative to the values in the CAA. At the southern part of the Chukchi Peninsula we found the highest fCO2sw values and the water was CO2 supersaturated, likely due to upwelling. In the study area, the calculated seaair CO2 flux varied between an oceanic CO2 sink of 140mmolm2d1 and an oceanic source of 18mmolm2d1. However, in the CAA and the northern Chukchi Sea, the sea ice cover prevented gas exchange, and the CO2 fluxes were probably negligible at this time of the year. Assuming that the water was exposed to the atmosphere by total melting and gas exchange would be the only process, the CO2 undersaturated water in the ice-covered areas will not have the time to reach the atmospheric CO2 value, before the formation of new sea ice. This study highlights the value of using high-frequency measurements to gain increased insight into the variable and complex conditions, encountered on the shelves in the Arctic Ocean.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.ATMOSENV.2009.04.026", "year": 2009, "title": "Investigations of an intense aerosol loading during 2007 cyclone SIDR A study using satellite data and ground measurements over Indian region", "abstract": "Tropical cyclones are prominent weather systems characterized by high atmospheric pressure gradients and wind speeds. Intense tropical cyclones occur in India during the pre-monsoon (spring), early monsoon (early summer), or post-monsoon (fall) periods. Originating in both the Bay of Bengal (BoB) and the Arabian Sea (AS), these tropical cyclones often attain velocities of more than 100 km h1 and are notorious for causing intense rain and storm surge as they cross the Indian coast. In this study, we examine the changes in the aerosol properties associated with an intense tropical cyclone SIDR, that occurred during 1116 November 2007 over BoB. This cyclone, accompanied with very strong surface winds reaching 223 km h1, caused extensive damage over Bangladesh. Ground-based measurements of Aerosol Optical Depth (AOD) in the neighboring urban environment of Hyderabad, India, showed significant variations due to changes in wind velocity and direction associated with the cyclone passage. The Terra-MODIS and AVHRR satellite images showed prevalence of dust particles mixed with emissions from anthropogenic sources and biomass-burning AS, while the aerosol loading over BoB was significantly lower. The positive values of Aerosol index (AI) obtained from the Ozone Monitoring Instrument (OMI) suggested the presence of an elevated aerosol layer over the West coast of India, AS and Thar Desert during and after the cyclone episode. Meteorological parameters from the MM5 mesoscale model were used to study the variations in winds associated with the cyclonic activity. Particulate matter loading over the region during the cyclone period increased by 45% with an accompanying decrease in columnar aerosol optical depth. The variations in Angstrom parameters suggested coarse-mode particle loading due to dust aerosols as observed in satellite data.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-9-8211-2009", "year": 2009, "title": "Direct measurements of the effect of biomass burning over the Amazon on the atmospheric temperature profile", "abstract": "Abstract. Aerosols suspended in the atmosphere interact with solar radiation and clouds, thus change the radiation energy fluxes in the atmospheric column. In this paper we measure changes in the atmospheric temperature profile as a function of the smoke loading and the cloudiness, over the Amazon basin, during the dry seasons (August and September) of 20052008. We show that as the aerosol optical depth (AOD) increases from 0.02 to a value of ~0.6, there is a decrease of ~4C at 1000 hPa, and an increase of ~1.5C at 850 hPa. The warming of the aerosol layer at 850 hPa is likely due to aerosol absorption when the particles are exposed to direct illumination by the sun. The large values of cooling in the lower layers could be explained by a combination of aerosol extinction of the solar flux in the layers aloft together with an aerosol-induced increase of cloud cover which shade the lower atmosphere. We estimate that the increase in cloud fraction due to aerosol contributes about half of the observed cooling in the lower layers.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1196/ANNALS.1439.010", "year": 2008, "title": "High Latitude Changes in Ice Dynamics and Their Impact on Polar Marine Ecosystems", "abstract": "Polar regions have experienced significant warming in recent decades. Warming has been most pronounced across the Arctic Ocean Basin and along the Antarctic Peninsula, with significant decreases in the extent and seasonal duration of sea ice. Rapid retreat of glaciers and disintegration of ice sheets have also been documented. The rate of warming is increasing and is predicted to continue well into the current century, with continued impacts on ice dynamics. Climate-mediated changes in ice dynamics are a concern as ice serves as primary habitat for marine organisms central to the food webs of these regions. Changes in the timing and extent of sea ice impose temporal asynchronies and spatial separations between energy requirements and food availability for many higher trophic levels. These mismatches lead to decreased reproductive success, lower abundances, and changes in distribution. In addition to these direct impacts of ice loss, climate-induced changes also facilitate indirect effects through changes in hydrography, which include introduction of species from lower latitudes and altered assemblages of primary producers. Here, we review recent changes and trends in ice dynamics and the responses of marine ecosystems. Specifically, we provide examples of ice-dependent organisms and associated species from the Arctic and Antarctic to illustrate the impacts of the temporal and spatial changes in ice dynamics.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2007GL031270", "year": 2007, "title": "Spatial variability of regional model simulated JuneSeptember mean precipitation over West Africa", "abstract": "The study examines the spatial variability of JuneSeptember 2003 mean precipitation rates (Pr03) simulated by a regional climate model on a horizontal grid with 0.5 spacing. In particular, it evaluates the relative impact of different initial conditions versus the influence of the lateral boundary conditions (LBC), and it compares small spatial scale distributions of modeled Pr03 to data from the Tropical Rainfall Measuring Mission (TRMM) and the NOAA Climate Prediction Center data for the African Famine Early Warning System (FEWS). Simulations over West Africa were made with the CCSR/GISS RM3, driven by synchronous data from NCEP reanalysis. A five-member ensemble for a single season was generated by staggering the initial conditions of each member by 36 hr within the period May 915, 2003. Results showed that the LBC influence dominated over that of differing initial conditions, implying that the precipitation simulations suffered little contamination of random noise. In a second evaluation, small spatial scale distributions of Pr03 were computed as the difference between Pr03 and spatially smoothed fields. Spatial correlations between the RM3 product versus the TRMM and FEWS small-scale components of Pr03 were highest using TRMM data provided at 1 elements. Results suggest that the model may be challenged to simulate realistic small-scale features of the seasonal mean precipitation field, and/or that observational data sets do not adequately capture these fine spatial features.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1098/RSTB.2006.1957", "year": 2007, "title": "Spatial and temporal operation of the Scotia Sea ecosystem: a review of large-scale links in a krill centred food web", "abstract": "The Scotia Sea ecosystem is a major component of the circumpolar Southern Ocean system, where productivity and predator demand for prey are high. The eastward-flowing Antarctic Circumpolar Current (ACC) and waters from the WeddellScotia Confluence dominate the physics of the Scotia Sea, leading to a strong advective flow, intense eddy activity and mixing. There is also strong seasonality, manifest by the changing irradiance and sea ice cover, which leads to shorter summers in the south. Summer phytoplankton blooms, which at times can cover an area of more than 0.5 million km2, probably result from the mixing of micronutrients into surface waters through the flow of the ACC over the Scotia Arc. This production is consumed by a range of species including Antarctic krill, which are the major prey item of large seabird and marine mammal populations. The flow of the ACC is steered north by the Scotia Arc, pushing polar water to lower latitudes, carrying with it krill during spring and summer, which subsidize food webs around South Georgia and the northern Scotia Arc. There is also marked interannual variability in winter sea ice distribution and sea surface temperatures that is linked to southern hemisphere-scale climate processes such as the El NinoSouthern Oscillation. This variation affects regional primary and secondary production and influences biogeochemical cycles. It also affects krill population dynamics and dispersal, which in turn impacts higher trophic level predator foraging, breeding performance and population dynamics. The ecosystem has also been highly perturbed as a result of harvesting over the last two centuries and significant ecological changes have also occurred in response to rapid regional warming during the second half of the twentieth century. This combination of historical perturbation and rapid regional change highlights that the Scotia Sea ecosystem is likely to show significant change over the next two to three decades, which may result in major ecological shifts.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1080/01431160601091787", "year": 2007, "title": "Assessing posttsunami effects on ocean colour at eastern Indian Ocean using MODIS Aqua satellite", "abstract": "The 2004 Indian Ocean tsunami had been reported to cause vast destruction on marine environment, but its effect on the primary production and upwelling event was unknown. Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua ocean colour imageries were used to assess the tsunami effects on the chlorophylla (chla) and turbidity variations. Chlorophylla and normalized water leaving radiance at 551 nm (nLw 551) before and after the tsunami event were processed using SeaWiFS data analysis system (SeaDAS), and the variations were examined. Results showed a sudden increase of chla and nLw 551 at the northwestern Sumatra and middle of Malacca Straits (MS) after the tsunami. At western Sumatra, high sedimentation caused by the backwash resulted in overestimation of the chla values. However, the chla in the upwelling area in the northern MS did not exhibit any significant changes. The chla variation in the northern MS was found to be related to the monsoon wind with about one week time lag. At the seriously eroded coastline along western Sumatra, continuous sedimentation was observed. The sedimentation problem became more severe during higher rainfall periods in April 2005. We strongly suggest a long term monitoring of this sedimentation problem.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.CATENA.2021.105871", "year": 2022, "title": "Changes of surface recovery at coseismic landslides and their driving factors in the Wenchuan earthquake-affected area", "abstract": "A major earthquake can trigger numerous landslides, which exert severe impacts on regional vegetation coverage. In some years following an earthquake, rainstorms can easily reactivate coseismic deposits and unstable hillslopes. Vegetation can improve the post-seismic slope instability by the root reinforcement effect, and it is significant to investigate the changes of surface recovery at coseismic landslides for a long-term assessment of post-earthquake geohazards. However, due to limited earth observations, it remains elusive that how long the surface vegetation of coseismic landslides caused by the 2008 Wenchuan earthquake will recover to the pre-earthquake level. We studied the long-term evolution of surface recovery in coseismic landslide-affected areas using multi-temporal Landsat images from 2000 to 2020. We calculated the vegetation recovery rates in different periods, which were used to quantify the rate of vegetation regrowth and landslide activity intensity. We found that 71.34% of the affected areas have been properly revegetated, and the area percentage of landslides in high activity, middle activity, low activity and dormant were 17.6%, 12.4%, 17.7% and 52.3%, respectively in 2020. To examine the factors controlling the surface recovery at coseismic landslides, we further analyzed the relationships between landslide recovery and eighteen influencing factors, and we found that elevation, peak ground acceleration, rainfall, lithology and gully density are the key factors that control landslide surface recovery over all others. Overall the trend of surface recovery at coseismic landslides suggests that the impact of the Wenchuan earthquake on the activities of shallow landslides almost ceases within 17 years in the Wenchuan earthquake-affected areas.", "labels": [ { "id": 5, "name": "Earthquakes" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/B978-0-12-816693-2.00015-9", "year": 2022, "title": "Surface ozone in Indian urban region", "abstract": "Atmospheric ozone has witnessed a steady increase attributable to anthropogenic activities aligned with the socioeconomic development of cities. Primary pollutants such as particulate matter, carbon monoxide, and nitrogen oxides have been given utmost priority in the air quality assessment studies conducted in the past. Ozone, one of the most important greenhouse gases, has been regarded as a major global concern due to its adverse impacts on the environment, human health, and vegetation. An understanding about the long-term as well as the short-term trends, underlying chemistry and prominent contributing factors for the accumulation of ozone in urban environments, is one of the key aspects that requires due consideration while developing the strategy for restricting its accumulation in the environment. In view of this, the present study aims to enrich the existing literature on ozone accumulation in urban settings by assessing the variability in ozone levels in Delhi city over a period of 10 years between 2008 and 2018 using satellite observations. The analysis in the present study has been restricted to assess the variations in the levels of total columnar ozone (TOC), nitrogen dioxide (NO2), and solar radiation (SR) over Delhi to assess the variations in surface ozone. The results of the analysis revealed that the pollutant has followed an increasing trend over the study region between 2008 and 2018, which is sure to increase in the future. TOC has witnessed an irregular trend over Delhi city between 2008 and 2018 with a significant rise from 2013 to 2015, indicating the need to restrain these levels. Furthermore, numerous studies have highlighted that the increasing levels of surface ozone pose various environmental, human health, and agricultural challenges. Thus, in view of this, the present study provides a preliminary analysis of long-term trends of surface ozone over Delhi city to strategize interventions and actions to restrict the increase in this new-age pollutant.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.RENENE.2022.03.110", "year": 2022, "title": "A Mediterranean Sea Offshore Wind classification using MERRA-2 and machine learning models", "abstract": "This paper uses a Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA-2) re-analysis to identify long-term Mediterranean Sea Offshore Wind (OW) classification possible locations. In particular, an OW classification based on the last 40-years period OW speeds highlighted the best areas for potential Offshore Wind Turbine Generators (OWTG) installations in the Mediterranean basin. Preliminary, long-term OW classification results show that several Mediterranean basin zones in the Aegean Sea, Gulf of Lyon, the Northern Morocco and Tunisia regions have attractive OW potential. Secondly, a combined forecasting model based on the wavelet decomposition method and long-term memory neural network has been developed to predict the short-term wind speed considering the last ten years of hourly data for Mediterranean areas. The results of the proposed model for wind speed prediction have been compared with other single models, Multilayer Perceptron (MLP) and Long Short-Term Memory (LSTM), highlighting a higher level of accuracy. Finally, three Weibull fitting algorithms have been provided to analyze the wind energy potential in the Mediterranean basin.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S11120-022-00958-Z", "year": 2022, "title": "Photosynthetic patterns during autumn in three different Salix cultivars grown on a brownfield site", "abstract": "Leaf senescence at the end of the growing season is a complex process stimulated by changes in daylength and temperature that prepares deciduous trees for winter by reducing photosynthetic rates and remobilization of nutrients. Extending the duration of photosynthetic activity could have important consequences for the translocation of heavy metals in the phytoremediation of contaminated sites using deciduous trees like willow. In the present study, three Salix cultivars (India, SX67, and Fish Creek) that were observed to maintain green leaves late into autumn were evaluated over an 11-week period extending from mid-September to mid-November on a brownfield site in Montreal, Canada. Gas exchange rates, chlorophyll fluorescence, and leaf pigments were measured weekly. A general trend of declining stomatal conductance and transpiration were observed early in the trial, followed by reductions in photosynthetic efficiency and concentrations of chl a, chl b, and carotenoids, in agreement with other studies. In particular, the cultivar Fish Creek had higher rates of gas exchange and pigment concentrations than either SX67 or India, but values for these parameters also declined more rapidly over the course of the trial. Both photoperiod and soil and air temperatures were strong drivers of changes in photosynthetic activity in all three of these cultivars according to correlation analyses. Further studies should focus on their biomass production and heavy metal accumulation capacity in light of the observed variation in photosynthetic activity stimulated by seasonal changes in light and temperature.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S00024-022-03113-W", "year": 2022, "title": "Observed and Simulated Characteristics of 2015 Chennai Heavy Rain Event: Impact of Land-Use Change, SST, and High-Resolution Global Analyses", "abstract": "The southern Indian city of Chennai received more than 1200 mm of rainfall between 5 November and 10 December 2015. The record-breaking rain exceeded the previous 24-h precipitation record (290 mm) on 1 and 2 December and resulted in severe urban flooding. Meteorological analysis from observational and reanalysis data sets shows that this rainfall event was the culmination of three synoptic-scale systems with oceanic moisture trajectories. The city has also witnessed dramatic urban sprawl in recent decades, and the feedback of urban heating on regional convection is postulated to be another critical factor in modulating the mesoscale environment and heavy rains. Accordingly, the study seeks to assess whether the Weather Research Forecasting (WRF) modeling system typically used for heavy rain prediction can better simulate this event by considering enhanced meteorological setup and urban feedback. Simulations were conducted using the WRF modeling system with different model configurations for 40 days (00 UTC 1 November until 00 UTC 11 December 2015), with a triple-nested domain and the finest grid spacing of 1.2 km centered over Chennai. The results indicate that the WRF modeling system broadly agrees with the observations, such as from the GPM-IMERG rainfall products. Model experiments also reveal the impact of increased urban built-up area on the rainfall distribution and the improvement in the model results using high-resolution atmospheric and SST initialization. The findings indicate that even for this synoptic-driven event, representing realistic urban land cover can aid the simulation of the heavy urban rainfall.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.30495/JONASS.2022.1951490.1031", "year": 2022, "title": "Comparison of development trends of Tehran and Isfahan cities and its effects on vegetation, climate and air pollution using GEE, Giovanni", "abstract": "Background and objective: Population growth and industrialization of cities have led to the rapid growth of urbanization and development of cities. Today, the evaluation of urban physical development using modern remote sensing techniques can provide basic information to planners. The purpose of this study is to investigate the trend of urban development and its effects on changes in vegetation, temperature, rainfall, and air pollution in the two metropolises of Tehran and Isfahan.Materials and methods: In this study, two systems Google Earth Engine (GEE) and Giovanni have been used to analyze indicators such as temperature, vegetation, humidity, and precipitation. NDVI maps and diagrams of two cities in 5- and 10-year periods were produced from MODIS satellite (2000 to 2021) and Landsat 8 (2013 to 2021).Results and conclusion: Urban development and population growth in Tehran have led to an increase in heat islands (LST) and temperature in the region, which has a direct effect on the reduction of snow and rain and, as a result, the reduction of runoff, vegetation, and soil moisture. Due to the development of industrial towns and residential constructions around Isfahan, destructive environmental effects related to vegetation, weather, and pollution in Mashhad, and the increase in urbanization and industry have led to a decrease in the level of vegetation and NDVI in this area. This conclusion was obtained that the obtained results confirm that the development of the cities of Tehran and Isfahan has destructive environmental effects on the weather and vegetation in all directions.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1080/10106049.2022.2113449", "year": 2022, "title": "Analysis of wildfires and associated emissions during the recent strong ENSO phases in Southern Africa using multi-source remotely-derived products", "abstract": "In southern Africa, drier conditions are more pronounced during the El Nino Southern Oscillation (ENSO) years, triggering wildfire activity and extreme drought conditions which, individually or together, lead to loss of crop productivity, deaths of livestock and wildlife, famine, degraded ecosystems, water quality and quantity. However, the fire characteristics in relation to the emissions from biomass burning and surface properties are only examined to a limited extent in the literature, especially in Africa, where anthropogenic activities largely determine the fire activity. This study uses the available data from multi-source remote sensing platforms to (1) analyse the spatial distribution of wildfires and associated emissions during strong El Nino (2015/2016) and La Nina (2010/2011) phases in southern Africa, and (2) examine the effects of the severe El Nino and La Nina years on the relationship between the emission parameters, vegetation parameters and climatic parameters. Generally, the results suggest more emissions from the wildfire in the El Nino phase than that of the La Nina. Overall, the Pearsons correlation clearly shows the influence and the relationship between the climate parameters themselves and also with emission parameters.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSENV.2022.119312", "year": 2022, "title": "A deep insight into state-level aerosol pollution in India: Long-term (20052019) characteristics, source apportionment, and future projection (2023)", "abstract": "The present study provides a national scenario of aerosol pollution with the long-term (20052019) trend, source apportionment, and future scenario (2023) for each of the Indian states. We used MODIS AOD and FRP, differential AODs from MERRA-2, and trace gases (NO2, SO2) data from OMI. Almost all the states of IGP fall under the red zone (highly vulnerable; AOD >0.5) whereas central, western, and a few south-Indian states fall under the orange zone (vulnerable; 0.4 < AOD >0.5). The most alarming feature is that most of the southern Indian states exhibit a shift from blue/green (less vulnerable/safe; AOD <0.4) to vulnerable zones in 2023 as observed using the auto-regressive integrated moving average (ARIMA) model. Principal component analysis (PCA) revealed that the coal-fired thermal power plant (TPP), vehicular, solid fuel/waste, and biomass burning are the major sources of aerosols for the vulnerable states at present and in the future. We estimated and proposed the TPP capacity (GW) that needs to be reduced to bring down the AOD to move the vulnerable zones to less vulnerable and safe zones. The present study would complement and strengthen the ongoing national missions to combat air pollution in India.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/ATMOS13030428", "year": 2022, "title": "Analysis of Wildfires in the Mid and High Latitudes Using a Multi-Dataset Approach: A Case Study in California and Krasnoyarsk Krai", "abstract": "In this study, we investigate the emissions from wildfires in the mid latitude (California) and high latitude (Krasnoyarsk Krai) during the periods of 1617 August 2020 and 28 July 2019, respectively. Wildfires are unique in themselves as they are driven by various factors such as fuel type, topology, and meteorology. In this study, we analyze whether there are any major variations in the emissions and transport of pollutants between two large wildfire cases in the mid latitude of California and high latitude of Krasnoyarsk Krai. The study is important to understand and characterize the emission regime from biomass burning of different land covers using a mutli-dataset approach. We analyze whether there are any major variations in the emissions and transport of pollutants from these wildfires. For example, the aerosol extinction coefficient profile showed smoke detected at the highest altitude of 9 km in Krasnoyarsk Krai, whereas in California the highest altitude was observed at approximately 6 km. Moreover, large values of black carbon (BC) concentration were observed in Krasnoyarsk Krai approximately 7 g/m3 compared to the 0.44 g/m3 observed in California. Areas with an immense dense vegetation are prone to large emissions. The results from this case study suggest that high latitude wildfires emit more pollutants than mid latitude wildfires. However, more studies in the future will be conducted to conclude this observation and finding with certainty.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/IJGI11070378", "year": 2022, "title": "Rapid Extreme Tropical Precipitation and Flood Inundation Mapping Framework (RETRACE): Initial Testing for the 20212022 Malaysia Flood", "abstract": "The 20212022 flood is one of the most serious flood events in Malaysian history, with approximately 70,000 victims evacuated daily, 54 killed and total losses up to MYR 6.1 billion. From this devastating event, we realized the lack of extreme precipitation and flood inundation information, which is a common problem in tropical regions. Therefore, we developed a Rapid Extreme TRopicAl preCipitation and flood inundation mapping framEwork (RETRACE) by utilizing: (1) a cloud computing platform, the Google Earth Engine (GEE); (2) open-source satellite images from missions such as Global Precipitation Measurement (GPM), Sentinel-1 SAR and Sentinel-2 optical satellites; and (3) flood victim information. The framework was demonstrated with the 20212022 Malaysia flood. The preliminary results were satisfactory with an optimal threshold of five for flood inundation mapping using the Sentinel-1 SAR data, as the accuracy of inundated floods was up to 70%. Extreme daily precipitation of up to 230 mm/day was observed and resulted in an inundated area of 77.43 km2 in Peninsular Malaysia. This framework can act as a useful tool for local authorities and scientists to retrace the extreme precipitation and flood information in a relatively short period for flood management and mitigation strategy development.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JASTP.2022.105927", "year": 2022, "title": "Potential utilization of air temperature, total electron content, and air relative humidity as possible earthquake precursors: A case study of Mexico M7.4 earthquake", "abstract": "This study examines ionospheric total electron content (TEC) perturbations from six International Global Navigation Satellite System stations (GNSS) including GUAT-Guatemala, SSIA-El Salvador, INEG-Mexico, MANA-Nicaragua, MDO1-United States of America, and BOGT- Colombia for several days around the occurrence of a major earthquake (M 7.4 and depth 20.0 km) in Mexico, June 23, 2020 at 10:29 Local Time (LT). The INEG station in the North-Northwest of the epicenter at a distance of about 936 km indicated a positive TEC anomaly on June 18, 2020, which can be possibly viewed as an earthquake precursor due to its occurrence during a quiet geomagnetic storm and inactive solar activity. Study findings reveal that other TEC perturbations may not be related to the earthquake, because they appeared during geomagnetic activities. Moreover, the atmospheric parameters have significant and synchronous deviations from the earthquake epicenter on June 13, 2020. The highest atmospheric chemical potential (ACP) is about 0.010 eV, atmospheric air temperature has positive deviation of 3.937 C at 15:00 LT, the lowest atmospheric relative humidity has negative deviation of 25.387% at 13:00 LT and outgoing longwave radiation (OLR) 27.58 W m2. Observations validate that in the earthquake preparation zone, variations in atmospheric air temperature and relative humidity reach at peak value during 10 days prior to the impending earthquake event with the later perturbations in the ionosphere.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.OCEANO.2022.06.003", "year": 2022, "title": "Physical control on the inter-annual variability of summer dissolved nutrient concentration and phytoplankton biomass in the Indian sector of the Southern Ocean", "abstract": "To understand the role of physical processes and their interannual variability on the dissolved nutrient concentration and phytoplankton biomass distribution, field data collected in the Indian sector of the Southern Ocean (ISSO) during the austral summer of 20092011 are used. In the subtropical zone, macronutrients were limited (N:P < 1, N:Si < 1, Si:P 1) and the phytoplankton biomass variability was mainly governed by the mesoscale eddy activity associated with the Agulhas Return Current. High nutrient low chlorophyll condition prevailed in the sub-Antarctic zone and further south. A South-North gradient of the upper layer dissolved SiO2 was higher than that of NO3. The sub-Antarctic zone was characterized by the highest N:Si ratio (>4) and it was associated with the enhanced draw down of silicate due to the winter/spring diatom blooms in the region. The chlorophyll-a (CHL) concentration in the Polar Frontal Zone was low (0.2 mg m3) in 2009 and 2010 but it was high (0.5 mg m3) in 2011. This increase in CHL in 2011 was due to the supply of dissolved iron from the strong winds and subsequent mixing during the winter of 2010. Further, the increased CHL values in the Antarctic zone (0.5 mg m3) in 2011 compared to 2009 and 2010 could be due to the increased sea ice melting associated with positive Southern Annular Mode. The increased phytoplankton biomass in the summer of 2011 coincides with an increase in nitrate utilization (N:P13) compared to 2009 and 2010. Observations showed that ISSO frontal zones are characterized by inter-annual variability in terms of nutrient utilization and phytoplankton biomass production.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/JOC.7799", "year": 2022, "title": "Long-term trends in aerosol optical properties and their relationship with cloud properties over southern India and Sri Lanka", "abstract": "Asia is one of the continents where aerosol levels are comparatively higher across the world. India and Sri Lanka are some of the regions in the South Asian continent where pollution is increasing rapidly due to the rise in industrialization. The present study investigated the interactions between atmospheric aerosol and cloud microphysical properties and their spatial, temporal, and seasonal variation at local and regional scales during 20002020 using remotely sensed data sets in south India and Sri Lanka. High values (>0.5) of annual mean aerosol optical depth (AOD) were detected over southern India. On the other hand, lower values (0.2) were detected over Sri Lanka. In terms of seasonality, a high level of AOD was registered in both southern India and Sri Lanka during the premonsoon and monsoon periods. The angstrom exponent (AE412-470) revealed the dominance of fine-mode particles during winter and the postmonsoon, generally from biomass burning and industrial activities. The long-term analysis exhibited an increasing trend of atmospheric aerosol concentration over southern India and Sri Lanka. Interestingly, there was a decrease in AOD during the year 2020; the reduction in anthropogenic activities in the region was attributed to the COVID-19 lockdown, hence less accumulation of pollutants in the atmosphere. AOD showed a positive correlation with cloud effective radius over the western areas along with the Indian Ocean, north, southeast, and southern end of India, while negatively correlated with high AOD areas such as northeast of the study domain. The AOD and cloud optical depth were positively correlated over continental areas, while negative correlations were notable over the Indian Ocean around Sri Lanka, implying heterogeneities of aerosol's effect on cloud microphysical properties over the study area. Finally, the results from wind circulation and backward air mass trajectories reveal higher concentrations of fine-mode particles associated with the continent, whereas coarse-mode particles originate from the oceans.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.DSR.2022.103836", "year": 2022, "title": "Spatial and temporal variability of the physical, carbonate and CO2 properties in the Southern Ocean surface waters during austral summer (2005-2019)", "abstract": "In situ measurements of sea surface temperature (SST), salinity (SSS), Total Alkalinity (AT) and Total Carbon (CT) were obtained during austral summer (mid-February to mid-March) from 2005 to 2019 in the Southern Ocean (SO), along a transect between Hobart, Tasmania and Dumont dUrville French Antarctic Station. The studied transect is divided in four regions from North to South: the Subtropical Zone (STZ), the Subantarctic Region (SAR), the Antarctic Region (AAR) and the Coastal Antarctic Zone (CAZ). Latitudinal distribution of measured SST, SSS, AT, CT as well as calculated pH, CO2 parameters (seawater fugacity of CO2 (fCO2sw), difference between seawater and atmospheric fCO2 (fCO2), CO2 flux (FCO2)) and satellite-derived Chlorophyll a (Chl-a) are discussed. We show that the variability of physical and carbonate parameters in the STZ and north of the SAR are related to the mesoscale activity. In the CAZ, the freshwater inputs from sea-ice melting strongly impact the variability of all parameters. The comparison between physical and carbonate parameters highlights that AT and CT are directly related to the latitudinal variability of SST and SSS. Study of the CO2 parameters shows that the transect is a sink of CO2 during February and March, with a mean FCO2 of 4.0 2.8 mmol m2 d1. The most negative values of FCO2 are found in the STZ and SAR north of 50S and in the AAR south of 62S, where biological activity is high. New simple empirical relationships are developed for AT from SST and SSS and for CT using SST, SSS and atmospheric fCO2 (fCO2atm) for the austral summer in the studied area. Using high resolution SSS and SST from the SURVOSTRAL program, trends of AT and CT are determined in the SAR and the AAR from 2005 to 2019. SST, SSS and AT increase over this period in the SAR, which might be explained by the southward migration of the Subtropical Front. In the AAR, no clear trend is detected. CT increases by 1.0 0.2 and 0.8 0.3 mol kg1 yr1 in the SAR and AAR respectively. The trend in the AAR is attributed to the increase in anthropogenic CO2 emissions in the atmosphere while, in the SAR, hydrographic changes also contribute to the increase. Using the coefficient associated with fCO2atm in the equation of CT, we estimate the impact of atmospheric CO2 increase on CT at 1.18 0.14 mol kg1 yr1 and 1.07 0.13 mol kg1 yr1 in the SAR and AAR respectively. Decreases in pH are observed in both regions (0.0018 0.0001 and 0.0026 0.0003 yr1 in the SAR and AAR respectively), indicating the sensitivity of surface waters in the area towards the development of ocean acidification processes under rising anthropogenic emissions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2022.128243", "year": 2022, "title": "AI-based ensemble modeling of landfill leakage employing a lysimeter, climatic data and transfer learning", "abstract": "Predicting leachate pollutants is of prime importance in detecting the amount of pollution in water resources adjacent to sources of leakage. In this study, Electrical Conductivity (EC) as a physicochemical water pollution parameter with the possibility of portable measurement was used as an indicator of leachate quality for the Tychy-Urbanowice operating and closed landfill complex. In order to simulate landfill conditions, two lysimeter experiments were conducted simultaneously. Using sensors mounted in the lysimeters, from the end of November 2018 to the end of December 2019, EC, waste temperature and waste moisture were measured for the open lysimeter and only waste moisture for the closed lysimeter. Additionally, meteorological data obtained from the nearest synoptic station and soil moisture and temperature acquired from the GLDAS satellite were employed as external data to analyze various conditions. Thereafter, Artificial Neural Network (ANN), Neuro-Fuzzy Inference System (ANFIS), and Emotional ANN (EANN) models were developed to determine the parameters affecting the EC value recorded for the open lysimeter and subsequently, predict the missing EC parameter of the closed lysimeter by employing the transfer learning method. Following that, in order to improve the precision of EC predictions, ensemble techniques were applied to the outputs of the models that were developed. The results showed that the moisture of the lysimeters made a significant contribution to the EC value prediction. It is worth mentioning that among ANN, ANFIS, and EANN, the EANN model yielded more precise results in EC estimation, with the average DC above 0.80 and 0.90 for individual and ensembled modeling in both the training and verification phases, respectively.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.5194/ACP-22-7417-2022", "year": 2022, "title": "Australian wildfire smoke in the stratosphere: the decay phase in 2020/2021 and impact on ozone depletion", "abstract": "Abstract. Record-breaking wildfires raged in southeastern Australia in late December 2019 and early January 2020. Rather strong pyrocumulonimbus (pyroCb) convection developed over the fire areas and lofted enormous amounts of biomass burning smoke into the tropopause region and caused the strongest wildfire-related stratospheric aerosol perturbation ever observed around the globe. We discuss the geometrical, optical, and microphysical properties of the stratospheric smoke layers and the decay of this major stratospheric perturbation. A multiwavelength polarization Raman lidar at Punta Arenas (53.2 S, 70.9 W), southern Chile, and an elastic backscatter Raman lidar at Rio Grande (53.8 S, 67.7 W) in southern Argentina, were operated to monitor the major record-breaking event until the end of 2021. These lidar measurements can be regarded as representative for mid to high latitudes in the Southern Hemisphere. A unique dynamical feature, an anticyclonic, smoke-filled vortex with 1000 km horizontal width and 5 km vertical extent, which ascended by about 500 m d1, was observed over the full last week of January 2020. The key results of the long-term study are as follows. The smoke layers extended, on average, from 9 to 24 km in height. The smoke partly ascended to more than 30 km height as a result of self-lofting processes. Clear signs of a smoke impact on the record-breaking ozone hole over Antarctica in SeptemberNovember 2020 were found. A slow decay of the stratospheric perturbation detected by means of the 532 nm aerosol optical thickness (AOT) yielded an e-folding decay time of 1920 months. The maximum smoke AOT was around 1.0 over Punta Arenas in January 2020 and thus 2 to 3 orders of magnitude above the stratospheric aerosol background of 0.005. After 2 months with strongly varying smoke conditions, the 532 nm AOT decreased to 0.03-0.06 from MarchDecember 2020 and to 0.0150.03 throughout 2021. The particle extinction coefficients at 532 nm were in the range of 1075 Mm1 in January 2020 and, later on, mostly between 1 and 5 Mm1. Combined lidarphotometer retrievals revealed typical smoke extinction-to-backscatter ratios of 69 19 sr (at 355 nm), 91 17 sr (at 532 nm), and 120 22 sr (at 1064 nm). An ozone reduction of 20 %25 % in the 1522 km height range was observed over Antarctica and New Zealand ozonesonde stations in the smoke-polluted air, with particle surface area concentrations of 15 m2 cm3.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1007/S11356-022-21319-2", "year": 2022, "title": "Improvements in SO2 pollution in India: role of technology and environmental regulations", "abstract": "India relies heavily on coal-based thermal power plants to meet its energy demands. Sulphur dioxide (SO2) emitted from these plants and industries is a major air pollutant. Analysis of spatial and temporal changes in SO2 using accurate and continuous observations is required to formulate mitigation strategies to curb the increasing air pollution in India. Here, we present the temporal changes in SO2 concentrations over India in the past four decades (19802020). Our analysis shows that the Central and East India, and Indo-Gangetic Plain (IGP) are the hotspots of SO2, as these regions house a cluster of thermal power plants, petroleum refineries, steel manufacturing units, and cement Industries. Thermal power plants (51%), and manufacturing and construction industries (29%) are the main sources of anthropogenic SO2 in India. Its concentration over India is higher in winter (DecemberFebruary) and lower in pre-monsoon (MarchMay) seasons. The temporal analyses reveal that SO2 concentrations in India increased between 1980 and 2010 due to high coal burning and lack of novel technology to contain the emissions during the period. However, SO2 shows a decreasing trend in recent decade (20102020) because of the environmental regulations and implementation of effective control technologies such as the flue gas desulphurisation (FGD) and scrubber. Since 2010, India's renewable energy production has also been increased substantially when India adopted a sustainable development policy. Therefore, the shift in energy production from conventional coal to renewable sources, solid environmental regulation, better inventory, and effective technology would help to curb SO2 pollution in India. Both economic growth and air pollution control can be performed hand-in-hand by adopting new technology to reduce SO2 and GHG emissions.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1039/D2EM00021K", "year": 2022, "title": "Relationship between surface dissolved iron inventories and net community production during a marine heatwave in the subarctic northeast Pacific", "abstract": "From winter 201314 to the end of 201516, a high pressure atmospheric system induced elevated sea surface temperatures in the offshore subarctic northeast Pacific, resulting in a marine heatwave. Increased stratification due to the heatwave resulted in shoaling of the winter mixed layer and a decrease in nutrient re-supply to the euphotic zone. Here, we investigate relationships between dissolved iron (dFe) and macronutrients, net community production (NCP), (micro)nutrient uptake ratios, and phytoplankton community composition in the winter and summer from 2012 to 2015 to gain insight into coupled biogeochemical responses to the heatwave. Our investigation highlights the importance of external dFe supply during marine heatwave events, as a more shallow mixed layer reduces the transport of essential (micro)macronutrients to the surface layer. We conclude that recycled dFe did not contribute to NCP in 2014, but rather the vertical displacement of dFe rich water unrelated to mixed layer deepening played a major role. In 2015, such transport was not detected, resulting in abnormally low dFe and shift toward higher biomass of pico- and nano-phytoplankton size-classes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.JMARSYS.2022.103749", "year": 2022, "title": "The multi-year comparisons of chlorophyll and sea ice in Greenland Sea and Barents Sea and their relationships with the North Atlantic Oscillation", "abstract": "The Arctic Ocean (AO) has experienced very significant warming in recent decades with clear impacts on the extent and depth of sea ice cover. Sea ice serves as a primary habitat and plays an important role in the AO marine food web. The surface distributions of chlorophyll_a (CHL), sea ice concentration (ICE), sea surface temperature (SST) and North Atlantic Oscillation (NAO) are analyzed in the study region (20W-50E, 70N-80N) over the decade (20032014). This region spans the Barents Sea (BS), Norwegian (NS) and Greenland Sea (GS). In general, the peak of spatial averaged CHL in the BS was about 60% higher than the GS. Due to elevated SST in the southern BS, CHL was much higher especially in 2010 and 2013. In 2011, there was a strong meridional gradient in CHL decreasing from south to north of the BS, and also a strong zonal gradient from the southern GS to the southern BS. The northern GS had higher CHL than the southern GS due to the increased ice melting and nutrient-enriched runoff from east Greenland glaciers to the northern and western coastal regions of the GS. Seasonal peaks of spatially averaged CHL occurred in April or May and were about two weeks earlier in the BS than the GS. Higher ice melt in the northern BS was the main reason for CHL blooms especially in 2010 and 2011. Earlier and more extensive ice melting and a persistent negative NAO index causing atmospheric circulation patterns that favoured ice loss were the possible drivers of enhanced phytoplankton blooms in 2010. A previous negative winter NAO is thought to be linked to an increase in ICE in the following spring. NAO is mostly negative during spring in the GS. Sea ice melt was positively correlated with CHL in the northern sector of the study region.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1109/TGRS.2022.3170890", "year": 2022, "title": "Changes in Surface Water Bodies Associated With Madoi (China) Mw 7.3 Earthquake of May 21, 2021 Using Sentinel-1 Data", "abstract": "On May 21, 2021 (UTC), an Mw 7.3 earthquake occurred in Madoi County of Qinghai Province (China). There was no damage to buildings or loss of life; however, surface manifestation was observed in the epicentral areas. The analysis of synthetic aperture radar (SAR) and ground observation data shows changes in the section of the Yellow River and some lakes within the epicentral region associated with this strong earthquake. The changes in radar backscattering coefficient (BC) in water bodies are observed attributed to turbidity from the intense shaking of the earthquake. The liquefaction locations observed in the field within the epicentral region, which is also supported by the changes in the BC derived from Sentinel-1 data.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.5194/ACP-22-5701-2022", "year": 2022, "title": "Smoke in the river: an Aerosols, Radiation and Clouds in southern Africa (AEROCLO-sA) case study", "abstract": "Abstract. The formation of a river of smoke crossing southern Africa was investigated during the Aerosols, Radiation and Clouds in southern Africa (AEROCLO-sA) campaign in September 2017. A complementary set of global and mesoscale numerical simulations as well as ground-based, airborne and space-borne observations of the dynamics, thermodynamics and composition of the atmosphere are used to characterize the river of smoke in terms of timing and vertical extent of the biomass burning aerosol (BBA) layer. The study area was under the synoptic influence of a coastal low rooted in a tropical easterly wave and a high-pressure system over the continent and westerly waves at mid latitudes, one of which had an embedded cut-off low (CoL). The coastal low interacted with the second of two approaching westerly waves and ultimately formed a mid-level tropical temperate trough (TTT). The TTT created the fast-moving air mass transported to the southwestern Indian Ocean as a river of smoke. The CoL, which developed and intensified in the upper levels associated with the first (easternmost) westerly wave, remained stationary above northern Namibia prior to the formation of the TTT and was responsible for the thickening of the BBA layer. This shows that the evolution of the river of smoke is very much tied to the evolution of the TTT, while its vertical extent is related to the presence of the CoL. The mechanisms by which the CoL, observed over Namibia in the entrance region of the river of smoke, influences the vertical structure of the BBA layer is mainly associated with the ascending motion above the BBA layer. In the presence of the CoL, the top of the BBA layer over northern Namibia reaches altitudes above 8 km. This is much higher than the average height of the top of the BBA layer over the regions where the smoke comes from (Angola, Zambia, Zimbabwe, Mozambique), which is 5 to 6 km. The results suggest that the interaction between the TTTs and the CoLs which form during the winter may have a role in promoting the transport of BBA from fire-prone regions in the tropical band to the temperate mid latitudes and the southwestern Indian Ocean.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/APP12115356", "year": 2022, "title": "Solar Energy Potential on Surfaces with Various Inclination Modes in Saudi Arabia: Performance of an Isotropic and an Anisotropic Model", "abstract": "The present work investigated the performance of an isotropic (LiuJordan, LJ) and an anisotropic (Hay) model in assessing the solar energy potential of Saudi Arabia. Three types of solar collectors were considered: with southward fixed-tilt (mode (i)), with fixed-tilt tracking the Sun (mode (ii)), and with varying-tilt tracking the Sun (mode (iii)). This was the first time such a study was conducted for Saudi Arabia. The average annual difference between anisotropic (Hay) and isotropic (LJ) estimates is least 38 kWhm2 year1 over Saudi Arabia for mode (i), and therefore, the LJ model can be used effectively. In modes (ii) and (iii), the difference is greater (197 and 226 kWhm2 year1, respectively). It is, then, up to the solar energy engineer to decide which model is to be used, but it is recommended that the Hay model be utilised for mode-(iii) solar collectors. These results fill a research gap about the suitability of models in practice. An interesting feature for the ratio of the annual mean solar energy yield of Hay over LJ as function of the latitude, , and the ground albedo, r, is the formation of a well for 29 31 and 1.15 r 1.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.3354/MEPS14004", "year": 2022, "title": "Total lipid and fatty acid composition of mesozooplankton functional group members in the NE Pacific over a range of productivity regimes", "abstract": "Fish, whales, and seabirds along the productive west coast of Vancouver Island (WCVI), NE Pacific, rely on copepod prey that are assumed to be rich in lipid. However, the total lipid (TL) and fatty acid content of most copepod species and other mesozooplankton in this region have not been measured. To assess the diets and quality of zooplankton prey off the WCVI, we investigated differences in lipid content and composition of mesozooplankton according to their taxonomic versus functional group identities. Copepods, chaetognaths, euphausiids, and amphipods, belonging to 3 different functional groups, were sampled on the WCVI during pre-, mid-, and post-bloom conditions. Compared to taxonomic classifications, the functional group approach was superior in its ability to discern statistical differences in TL among zooplankton and between seasons. Furthermore, multivariate analyses using zooplankton fatty acid composition from all oceanographic regimes produced 3 to 4 statistically different clusters of species that corroborated functional group designations. However, some trophic flexibility was observed in several copepod species, particularly Calanus marshallae, that may relate to food scarcity or the presence of potentially noxious prey. The omnivorous-herbivorous functional group frequently contained higher amounts of TL and masses of essential fatty acids than the carnivorous group. Euphausiids and C. marshallae contributed the most lipid (mg m-3) to the pelagic lipid pool, due to very high lipid content and high abundance, respectively. However, on the continental slope and shelf break, chaetognaths and Neocalanus spp. copepods contributed substantially to the lipid pool.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.4209/AAQR.220026", "year": 2022, "title": "Variability and Source Characterization of Regional PM of Two Urban Areas Dominated by Biomass Burning and Anthropogenic Emission", "abstract": "ABSTRACT Identifying the sources and formation pathways of particulate matter (PM) and its components is important to determine the impact of atmospheric aerosols on human health and the warming of the global atmosphere. Here, we characterized the variability of the eleven-year concentration and the origin of PM2.5 in two urban regions (Metro Manila and Boracay) in the Philippines, a country in South East Asia (SEA) with high local anthropogenic emissions and frequently impacted by transboundary pollution. The surface concentration of PM2.5 was analyzed using simulated and reanalyzed satellite data (MERRAero), complemented, and validated with filter measurements for PM2.5 and black carbon (BC). The PM2.5 masses in Metro Manila (12.3 2.4 g m3) and Boracay (12.9 3.6 g m3) were comparable yet with varying concentrations of aerosol components Anthropogenic related components of PM (organic carbon, sulfate, and BC) were more enhanced in the metropolis region (4.9 g m3) than in the prime tourist spot (2.72 g m3). Sulfate formation impacted the aerosol mass in Metro Manila, with the photochemical oxidation of SO2 as the predominant production pathway of sulfates. Analysis of regional organic matter (OM) and BC in Boracay revealed extensive transboundary transport of biomass burning (BB) plumes from equatorial SEA countries. Also, the ratio of OM and SO4 was utilized as a quick proxy for source characterization. Metro Manila and Boracay reported 0.77 0.20 and 1.06 0.55, highlighting the evident impact of traffic emissions in the PM mass in the metropolis region. For Boracay, the mixed contributions of BB and vehicular activities influenced the formation of PM. Overall, the reanalysis of satellite data captured the long-term variability and origins of surface PM in two vital urban regions in the Philippines. The utilization of MERRAero will be an important procedure in making regulatory decisions on regional pollution control.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.154867", "year": 2022, "title": "Trends in the types and absorption characteristics of ambient aerosols over the Indo-Gangetic Plain and North China Plain in last two decades", "abstract": "The sixth assessment report released by the Intergovernmental Panel on Climate Change (IPCC) in 2021 states that our inadequate understanding of magnitudes and trends of atmospheric aerosols, particularly over Asia, is a major source of uncertainty in climate change. In this study, the climatology and trends in different types of aerosols with focus on absorbing aerosols over Kanpur located in the Indo-Gangetic Plain (IGP) in South Asia and Beijing in the North China Plain (NCP) in East Asia are derived for the first time. We perform a first analysis of high-quality time series of columnar aerosols observations over a period of nearly two-decades, along with satellite observations to provide a broader regional perspective. The satellite retrieved aerosol Angstrom exponent (AE) values have increased (1020%) suggesting an increasing contribution of fine aerosols to aerosol optical depth (AOD) over Asia in last 2-decades. Among the three aerosol types [urban-industrial (UI), biomass burning (BB), and dust (DU)], only UI and BB aerosols are present over Kanpur throughout the year, while DU is present along with UI and BB aerosols only during pre-monsoon and monsoon. Overall, there is a positive trend in BB aerosols over both Kanpur and Beijing, a positive (negative) trend in UI aerosols over Kanpur (Beijing), and positive (negative) trend in dust over Beijing (Kanpur). However, only the positive trend in BB aerosol type over Kanpur is statistically significant. Further, among the three absorbing aerosol types [mostly black carbon (MBC), mostly dust (MDU), and mixed (MIX) containing BC and dust], only MBC and MIX are present in post-monsoon and winter over IGP, and MDU is present along with MBC and MIX only during pre-monsoon and monsoon, which is in agreement with aerosol types found. Trends in MBC, MIX and MDU over Kanpur in IGP and in MIX over Beijing are statistically significant. These trends are attributed mainly to the changes in anthropogenic aerosol emissions, and not to natural and climatic factors as their changes are relatively small. These findings on hitherto unavailable climatology and trends in aerosols and absorbing aerosols over two global aerosol hotspots and identified contrasts will be crucial in model simulations to better decipher the aerosol-climate interactions over Asia.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41598-022-09281-Y", "year": 2022, "title": "Aerosol emissions and gravity waves of Taal volcano", "abstract": "The Taal volcano (14.0 N, 121.0 E) in Philippines erupted in JanuaryFebruary 2020, with a part of aerosols drifted northward and detected by a lidar system at Kaohsiung city (22.37 N, 120.15 E), Taiwan. The aerosol observed on Feb 11 is special for its high-altitude distributions at 47 km with discrete structures which can be resolved into a sinusoidal oscillation of ~ 30 min period, suggesting a case of wave event caused by the eruptions. We report in this paper the gravity wave generated by the volcanic eruptions and its effects on aerosol emissions. By studying the temperature and pressure data in the Taal region using radiosonde data, we found atmospheric gravity waves with powers correlated with the optical thickness (AOD) at 550 nm measured by the Moderate Resolution Imaging Spectrometer (MODIS) satellite. This study presents the first observation of modulation of the aerosol emissions by the volcanic gravity waves and a case of coupling of dynamics and chemistry.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/SU14063528", "year": 2022, "title": "A Qualitative Assessment of the Trends, Distribution and Sources of Methane in South Africa", "abstract": "Methane (CH4) is the second most important greenhouse gas (GHG) in terms of its concentration and impact on the climate. In the present study, we investigate the trends, sources and distribution of CH4 in South Africa. The study uses satellite datasets from Sentinel-5P and the Atmospheric Infrared Sounder (AIRS). The study also uses credible datasets from the World Bank, Statistics South Africa and the Global Methane Initiative (GMI). The results show an increasing trend of CH4 from 19701989. A turning point is observed in 1989, where a decreasing trend is observed from 19892001. An increasing trend is then observed from 2001 to 2021. A high concentration of CH4 is observed in the northern and interior parts of South Africa. The results also show that CH4 concentration is influenced by seasonal variations. The SeptemberOctoberNovember (SON) season has the highest CH4 concentration distribution in South Africa. The World Bank, Statistics South Africa and the GMI CH4 indictors show that agricultural activities, i.e., involving livestock, are the greatest emitters of CH4 in South Africa, followed by landfill sites. From the livestock data, sheep are the highest emitters of CH4. The increasing CH4 trend is a concern and efforts need to be made to drastically reduce emissions, if South Africa is to meet the 1997 Kyoto Protocol, 2015 Paris Agreement, sustainable development goal 13 (SDG 13) and the COP26 outcome agreements.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/ATMOS13030468", "year": 2022, "title": "Analyzing the Characteristics of Cloud Condensation Nuclei (CCN) in Hebei, China Using Multi-Year Observation and Reanalysis Data", "abstract": "The study of the characteristics and variations of cloud condensation nuclei (CCN) plays an important role in understanding the effects of aerosolcloud interactions. This paper selected observation data in a city region of Shijiazhuang in North China from 2005 to 2007, along with the corresponding MERRA-2 and ERA5 data, to analyze the characteristics of CCN, sort the factors affecting the diurnal variation of CCN number concentration (NCCN) according to their importance, and build the relationship between NCCN and supersaturation (SS) in the heavily polluted region. The results show that there was a bimodal distribution of a daily time series for NCCN in Shijiazhuang, China. By calculating the correlation between CCN and pollutants observed in winter 2007, we identified that the dominant factor for peaks of NCCN is SO2 in the morning but NO2 in the evening. We also ranked the factors affecting the diurnal variation of NCCN by using observation and reanalysis data and found that the concentration of pollutants is the greatest impact factor in summer, but the atmospheric stability is the greatest factor in winter. Finally, we determined the relationship between NCCN and SS according to the Twomey formula (NCCN=cSSk) and found there was a reasonable value range (i.e., 0.5~0.7) for the parameter k in East and North China. Specifically, it is more reasonable for k to be 0.5 in summer and 0.7 in winter.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00024-016-1366-0", "year": 2017, "title": "Remote Sensing of Atmospheric and Ionospheric Signals Prior to the Mw 8.3 Illapel Earthquake, Chile 2015", "abstract": "In the present study, a number of atmospheric and some ionospheric anomalies are analyzed, which were recorded prior to the Mw 8.3 Illapel earthquake of September 16, 2015. This very large earthquake occurred in Central Chile, close to the coast, as the result of thrust faulting on the interface between the Nazca Plate and South American continent. Using remotely sensed data extracted from NASA/Giovanni, NOAA/NCEP, and NOAA/NGDC, atmospheric and ionospheric anomalies were observed that co-registered 3540 and 2530 days prior to the main shock, respectively. With reference to long-term time series over the epicentral area, significant atmospheric anomalies were recorded for cloud cover, geopotential height, precipitation rates, surface air pressure, omega, stream function, and wind vectorsall in the time window of August 510, 2015, 3540 days prior to the main shock. Anomalous TEC maps were recorded for the same time period. Satellite images indicate the formation of an unusual cyclone, presumably triggered by air turbulences and abnormal atmospheric conditions over the epicentral area, including strong vertical winds. Data from the Jicamarca radio observatory in Peru, more than 2000 km to the North, reveal anomalous ionospheric variations on August 1520, 2015 with respect to international reference ionosphere thickness parameters and the altitude of the F layer. The observed anomalies are consistent with processes that occur at the ground-to-air interface due to the stress activation of peroxy defects in the hypocentral volume. The flow of positive hole charge carriers to the Earth surface expected to have led to massive air ionization, generating at first primarily positive airborne ions, then negative air ions plus ozone. Understanding the sequence of processes inside the Earths crust and at the ground-to-air interface provides information not previously available about the causal and temporal linkages between the various pre-earthquake phenomena and the future seismic event.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JENVMAN.2020.111496", "year": 2021, "title": "The impact of COVID 19 on air pollution levels and other environmental indicators - A case study of Egypt", "abstract": "The outbreak of coronavirus disease (COVID-19) not only affected health and economics, but also its effect extended to include other aspects, such as the environment. Using Egypt as a case study, this paper presents the impact of COVID-19 pandemic on air pollution levels by studying nitrogen dioxide (NO2), ozone (O3), particulate matter represented in absorbing aerosol index (AAI), carbon monoxide (CO), and greenhouse gas (GHG) emissions. The paper also highlights the impact of COVID-19 pandemic on other environmental indicators including environmental noise, medical and municipal solid wastes. The paper presents the Egyptian COVID-19 story from its different angles including the development of confirmed COVID-19 cases, containment measures from the government, the impact on the country's economy and the national energy consumption so as to effectively evaluate the effect on both the air pollution levels and the other studied environmental indicators. For the other environmental indicators, a strong link was observed between COVID-19 lockdown and the reduction in environmental noise, beaches, surface and groundwater pollution. For environmental noise, this has been confirmed by officially governmental announcements which reported that the level of environmental noise in Egypt was reduced by about 75% during the lockdown period. On the other hand, there are some negative effects, including an increase in medical solid waste (from 70 to 300 ton/day), municipal solid waste, as well as a less efficient solid waste recycling process. For air pollution levels, the data were obtained from National Aeronautics and Space Administration (NASA) and European Space Agency satellite data sets. The data for the lockdown period in 2020 have been extracted and compared to the corresponding months in the selected baseline period (20152019) to identify the effect that the lockdown period had on the air pollution levels in Egypt with focus on Cairo and Alexandria governorates. It was found that the AAI decreased by about 30%, the NO2 decreased by 15 and 33% over Cairo and Alexandria governorates, respectively, and that the CO decreased by about 5% over both governorates. In addition, the GHG emissions in Egypt were reduced by at least 4% during the pandemic. In contrast, ozone levels increased by about 2% over Cairo and Alexandria governorates. It can be concluded that the implemented containment measures during COVID-19 pandemic had resulted in both positive and negative environmental impacts. The positive environmental impacts are not sustainable and deterioration on them is expected to occur after the lockdown as it was before the pandemic. Therefore, stricter laws must be enacted to protect the environment in Egypt.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.47191/JEFMS/V4-I12-14", "year": 2021, "title": "A Spatial Econometric Analysis of Air Pollutant Concentrations and Economic Growth on Public Health: Empirical Evidence from Central Asian Countries", "abstract": "Air pollution of the countries of Central Asia has affected not only the health of the population since 1990 but also influenced the environment. This study has been made empirically analyzes the spatial autocorrelation analysis that is based on the 1991 to 2017 database of Central Asian countries on the socio-economic factors influencing the concentration of Sulfur Dioxide (SO2), Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Ozone (O3), and Particulate Matter (PM2.5) in the air. Besides, this study validated Global Moran's I statistics to determine spatial positive autocorrelations. The results show that there is a strong correlation between air pollution concentrations and Gross Domestic Product (GDP) per capita. The achievement identified that the concentrations of SO2, CO, NO2, O3, and PM2.5 have a spatial aggregation and distribution effect, which is significantly influenced by the spatial characteristics and the Central Asian Regional Economic Unions. It also determined that an energy policy of a country can be affected the emissions of air pollutants from neighboring countries due to policy effects. Therefore, there is a need for regional coordination of environmental policies and the transfer of pollution-intensive industries, to keep air pollution in countries of Central Asia at a normal level. In addition to the empirical results of this study, the following two conclusions can be identified. First, it identified the need for a unified policy to reduce air pollution to reduce emissions from air pollution sources. Second, there is a need for a renewable energy policy for the development and promotion of renewable energy.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1134/S0001433821090425", "year": 2021, "title": "Study of Thermal Fields before Strong Earthquakes in Turkey on March 8, 2010 (M = 6.1), and January 24, 2020 (M = 6.7)", "abstract": "Thermal-field anomalies recorded during the preparation and occurrence of strong earthquakes on March 8, 2010 (M = 6.1), and January 24, 2020 (M = 6.7), in Turkey, are studied using satellite data. Temperatures of the surface and atmospheric near-surface layer, as well as outgoing longwave radiation registered by the AIRS sensor of the Aqua satellite, are used for the analysis. The processing results have allowed us to establish that positive variations in surface and atmosphere temperatures appeared 712 days before the studied seismic events with M = 6.1 and M = 6.7, and these variations marked the onset of formation of the outgoing longwave radiation anomalies registered over the North and East Anatolian tectonic faults. The thermal-field anomalies detected during the preparation of the earthquakes in Turkey confirm the presence of heat generation effects between the surface and the upper cloud edge. These effects can be used as short-term remotely registered precursors of strong seismic events.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021PA004286", "year": 2022, "title": "Suitability of the Coralline Alga Clathromorphum compactum as an Arctic Archive for Past Sea Ice Cover", "abstract": "Arctic sea ice cover has been steeply declining since the onset of satellite observations in the late 1970s. However, the available annually resolved sea ice data before this time are limited. Here, we evaluated the suitability of annual trace element (Mg/Ca) ratios and growth increments from the long-lived annual increment-forming benthic coralline red alga, Clathromorphum compactum, as high-resolution sea ice cover archive. It has previously been shown that the growth of C. compactum is strongly light controlled and therefore greatly limited during the polar night and underneath sea ice cover. We compare algal data from 11 sites collected throughout the Canadian Arctic, Greenland, and Svalbard, with satellite sea ice data. Our results suggested that algal growth anomalies most often produced better correlations to sea ice concentration than Mg/Ca ratios or when averaging growth and Mg/Ca anomalies. High Arctic regions with persistently higher sea ice concentrations and shorter ice-free seasons showed the strongest correlations between algal growth anomalies and satellite sea ice concentration over the study period (19792015). At sites where ice breakup took place before the return of sufficient solar irradiance, algal growth was most strongly tied to a combination of solar irradiance and other factors such as temperature, suspended sediments, phytoplankton blooms, and cloud cover. These data are the only annually resolved in situ marine proxy data known to date and are of utmost importance to gain a better understanding of the sea ice system and to project future sea ice conditions.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/APP112311564", "year": 2021, "title": "Solar Potential in Saudi Arabia for Flat-Plate Surfaces of Varying Tilt Tracking the Sun", "abstract": "The objective of the present work is to investigate the performance of flat-plate solar panels in Saudi Arabia that continuously follow the daily motion of the sun. To that end, the annual energy sums are estimated for such surfaces at 82 locations covering all Saudi Arabia. All calculations use a surface albedo of 0.2 and another one with a near-real value. The variation of the solar energy sums on annual, seasonal, and monthly basis is given for near-real ground albedos; the analysis provides regression equations for the energy sums as function of time. A map of the annual inclined solar energy for Saudi Arabia is derived and presented. The annual energy sums are found to vary between 2159 and 4078 kWhm2year1. Finally, a correction factor, introduced in a recent publication, is used; it is confirmed that the linear relationship between the correction factor and the ground-albedo ratio is general enough to be graphically representable as a nomogram. A discussion regarding the differences among solar systems on horizontal, fixed-tilt, 1-axis, and 2-axis systems is presented.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ATMOSENV.2021.118893", "year": 2022, "title": "Quantifying the impact of biomass burning and dust storm activities on aerosol characteristics over the Indo-Gangetic Basin", "abstract": "The high aerosol loading over the entire Indo-Gangetic Basin (IGB) region in the northern India attracted attentions of scientific community especially when about 900 million people living in the areas suffered with poor air quality due to intense fog, haze and smog during the post-monsoon/winter period and dust storm activity during the summer period. The present study focused on first long-term comparative study to quantify the aerosol characteristics during the biomass burning (October-November) and dusty (April-June) periods using satellite measurements from 2004-2018 at three different locations: Jaipur, Kanpur and Ballia over IGB. The highest aerosol optical depth (AOD) values for the biomass (0.74 0.35) and dusty period (0.63 0.34) were observed at Kanpur during the entire study period. The finer particles were found to be dominant during the biomass period at all the locations. During the biomass burning period, an increased AOD trend was observed at Ballia (0.017 year1), followed by Kanpur (0.0144 year1) and Jaipur (0.0061 year1) whereas during the dusty period, an increasing trend was observed at Ballia (0.0074 year1) and decreasing trend over Jaipur (0.0132 year1) and Kanpur (0.0083 year1). During the biomass burning period, anthropogenic aerosol (AA) types were found to be dominant over Kanpur (52%) and Ballia (56%) while clean condition (CC) aerosol type was dominant over Jaipur (69%). On the other hand, during dusty period, the highest contribution of desert dust (DD) was observed at Kanpur (37%) and Ballia (30%); however, CC type of aerosol dominated over Jaipur (42%). The potential source sectors and the transport pathways of pollutants have been widely characterized at all the stations using the potential source contribution function (PSCF) and concentration weighted trajectory (CWT) analyses with the backward air mass trajectories. Results revealed that the high levels of aerosol over the stations are mainly from the local areas and also from the upper and middle IGB region.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S11069-021-05199-2", "year": 2022, "title": "Could road constructions be more hazardous than an earthquake in terms of mass movement?", "abstract": "Roads can have a significant impact on the frequency of mass wasting events in mountainous areas. However, characterizing the extent and pervasiveness of mass movements over time has rarely been documented due to limitations in available data sources to consistently map such events. We monitored the evolution of a road network and assessed its effect on mass movements for a 11-year window in Arhavi, Turkey. The main road construction projects run in the area are associated with a hydroelectric power plant as well as other road extension works and are clearly associated with the vast majority (90.1%) of mass movements in the area. We also notice that the overall number and size of the mass movements are much larger than in the naturally occurring comparison area. This means that the sediment load originating from the anthropogenically induced mass movements is larger than its counterpart associated with naturally occurring landslides. Notably, this extra sediment load could cause river channel aggregation, reduce accommodation space and as a consequence, it could lead to an increase in the probability and severity of flooding along the river channel. This marks a strong and negative effect of human activities on the natural course of earth surface processes. We also compare frequency-area distributions of human-induced mass movements mapped in this study and co-seismic landslide inventories from the literature. By doing so, we aim to better understand the consequences of human effects on mass movements in a comparative manner. Our findings show that the damage generated by the road construction in terms of sediment loads to river channels is compatible with the possible effect of a theoretical earthquake with a magnitude greater than Mw = 6.0.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JD034913", "year": 2021, "title": "Evaluation of Biogenic Organic Aerosols in the Amazon Rainforest Using WRF-Chem With MOSAIC", "abstract": "Biogenic secondary organic aerosol (BSOA) accounts for 70%80% of submicron aerosol over the Amazon rainforest. However, uncertainties with regard to the chemical formation pathway, mass budget, and radiative impact of BSOA in the region still remain high. To address the issue, we used a regional chemistry transport model (WRF-Chem-MOSAIC) to evaluate the budget of BSOA in the Amazon forest during the wet season (March) of 2014 when the air mass was clean from influences from anthropogenic and biomass burning emissions. We found that the default model underestimated the surface concentration of submicron organic aerosol (OA) by 57% at a ground measurement site (T3). We subsequently updated the WRF-Chem-MOSAIC model by including SOA formation from isoprene epoxydiols (IEPOX-SOA) and SOA aging schemes. The updated model reproduced the observed submicron OA concentration well with an overestimation of only 2.5%. With the updated model, we will show that IEPOX-SOA accounts for 23% of surface submicron OA averaged over the entire Amazon rainforest. The modeled surface SOA (smaller than 2.5 m in diameter) concentration in the Amazon region was about a factor of 14 larger than the global mean. Finally, a sensitivity study was conducted which showed that convective plumes can remove more than 40% of submicron OA below 5 km in the Amazon region. Overall, our study highlights the importance of IEPOX chemistry as well as the convective removal processes in the global SOA budget.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3390/JMSE7020050", "year": 2019, "title": "Exploring Possible Influence of Dust Episodes on Surface Marine Chlorophyll Concentrations", "abstract": "Desert dust deposition is thought to act as fertilizer for phytoplankton growth, since it is\nrich in the required nutrients. The Mediterranean Sea is a nutrient poor marine environmentwith\nits eastern part being the most oligotrophicwhich is subject to dust transport. The Hellenic\nSeas are part of this low-nutrient, low-chlorophyll environment and they are also affected by dust\ndeposition events. Thus, the dust fertilizing effect can be particularly important, especially during\nthe stratification period, when the nutrients needed for phytoplankton growth are not imported from\ndeeper layers. Some individual dust events are examined here in respect of their possible influence on\nphytoplankton, through the observed variations of satellite derived chlorophyll concentrations. Two\nstrong dust events that were also extreme weather events and three events in the JuneSeptember\nstratification period are examined for the Hellenic Seas as well as a strong dust event in the Central\nMediterranean Sea. The results, only when based on absolute chlorophyll differences above 50%, show\nthat dust events seem to favour phytoplankton abundance mainly during the low productive period;\nhowever, these differences are area-limited. The difficulty of reaching safe results through specific dust\nevents and discriminating between other meteorological factors favouring phytoplankton growth are\nalso discussed.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.18052/WWW.SCIPRESS.COM/ILNS.58.35", "year": 2016, "title": "Spatiotemporal monitoring of CO2 and CH4 over Pakistan using Atmospheric Infrared Sounder (AIRS)", "abstract": "Carbon dioxide (CO 2 ), Methane (CH 4 ) are two most potent greenhouse gases and are\nmajor source of climate change. Human activities particularly fossil fuels burning have caused\nconsiderable increase in atmospheric concentrations of greenhouse gases. CO 2 contributes 60% of\nanthropogenic greenhouse effect whereas CH 4 contributes 15%. Ice core records also show that the\nconcentrations of Carbon dioxide and methane have increased substantially. The emission of these\ngases alters the Earths energy budget and are drivers of climate change. In the present study,\natmospheric concentration of CO 2 and CH 4 over Pakistan is measured using Atmospheric Infrared\nSounder (AIRS). Time series and time averaged maps are prepared to measure the concentrations of\nCO 2 and CH 4 . The results show considerable increase in concentration of Carbon dioxide and\nmethane. The substantial increase in these concentrations can affect human health, earth radiative\nbalance and can damage crops.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.3390/RS14030549", "year": 2022, "title": "Can Forest Fires Be an Important Factor in the Reduction in Solar Power Production in India?", "abstract": "The wildfires over the central Indian Himalayan region have attracted the significant attention of environmental scientists. Despite their major and disastrous effects on the environment and air quality, studies on the forest fires impacts from a renewable energy point of view are lacking for this region. Therefore, for the first time, we examine the impact of massive forest fires on the reduction in solar energy production over the Indian subcontinent via remote sensing techniques. For this purpose, we used data from the Moderate Resolution Imaging Spectroradiometer (MODIS), the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIPSO), the Satellite Application Facility on support to Nowcasting/Very Short-Range Forecasting Meteosat Second Generation (SAFNWC/MSG) in conjunction with radiative transfer model (RTM) simulation, in addition to 1-day aerosol forecasts from the Copernicus Atmosphere Monitoring Service (CAMS). The energy production during the first quarter of 2021 was found to reach 650 kWh/m2 and the revenue generated was about INR (Indian rupee) 79.5 million. During the study period, the total attenuation due to aerosols and clouds was estimated to be 116 and 63 kWh/m2 for global and beam horizontal irradiance (GHI and BHI), respectively. The financial loss due to the presence of aerosols was found to be INR 8 million, with the corresponding loss due to clouds reaching INR 14 million for the total Indian solar plants capacity potential (40 GW). This analysis of daily energy and financial losses can help the grid operators in planning and scheduling power generation and supply during the period of fires. The findings of the present study will drastically increase the awareness among the decision makers in India about the indirect effects of forest fires on renewable energy production, and help promote the reduction in carbon emissions and greenhouse gases in the air, along with the increase in mitigation processes and policies.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105991", "year": 2022, "title": "Evaluation of surface solar radiation trends over China since the 1960s in the CMIP6 models and potential impact of aerosol emissions", "abstract": "Accurate representation of surface solar radiation (SSR) trends is an important indicator for global climate models (GCMs) to correctly reproducing the historical climate evolution. This study examines the annual mean SSR trends in China under all-sky and clear-sky conditions for the period 19612014 in 34 Coupled Model Intercomparison Project Phase 6 (CMIP6) models using the latest homogenized in-situ SSR dataset. The site-observed annual mean SSR over China shows a significant decadal decline during 19612005 but an uptrend during 20062014, with the trends being 6.4 (8.6) W m2 and + 2.5 (+5.9) W m2 per decade under all-sky (clear-sky) condition, respectively. All CMIP6 models simulate the sustained decline in SSR over China for the period 19612005 but significantly underestimate the dimming. The model results show trends of 1.9 0.5 W m2 and -2.5 0.7 W m2 per decade during 19612005 under all-sky and clear-sky conditions, respectively, which are around one third of the observed results. Furthermore, the models fail to capture the reversal of SSR trends in China during 20062014, with the trends being 1.1 1.7 W m2 and -2.2 0.9 W m2 per decade under all-sky and clear-sky conditions, respectively. We infer that the underestimation of anthropogenic aerosol emissions, especially absorbing black carbon emissions cause the underestimated simulation of SSR in dimming period over China. After 2005, the unseasonal increase in carbonaceous aerosol emissions and the weaker decline of sulfur dioxide emissions in China in the models result in an opposite SSR trends relative to the trends based on the site-observations. Our results suggest that improving the anthropogenic aerosol emissions inventory will be useful for generating a more accurate reproduction of the regional SSR evolution over China in GCMs.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.JASTP.2021.105802", "year": 2022, "title": "Atmospheric and ionospheric precursors associated with Mw 6.5 earthquakes from multiple satellites", "abstract": "The ionospheric monitoring satellites aid in correlating the lithospheric variation in ionosphere through Lithosphere-Atmosphere-Ionosphere coupling (LAIC) over the epicenter of future earthquake (EQ). In the present paper, we studied variations in ionosphere associated to two large magnitude EQs (Mw 6.5) and low epicentral depth EQs of less than 12 km in Plasma Density (PD), Slant Total Electron Content (STEC) and Electron Temperature (ET) of European Space Agency's (ESA) Swarm-three satellites (Swarm-A, -B, and C). These anomalies are investigated in the Swarm data for 60 days before/after each main shock. The anomalies are detected by statistically implemented median (M) and standard deviation () method within the Dobrovolsky's area. In order to exclude the geomagnetic perturbations, we have selected the ionospheric data in quiet geomagnetic conditions. Anomalous variations in Swarm-A data occur in ET and STEC for the USA event, and similarly, significant perturbation is clear in STEC of Swarm-B before the Mw 6.5, USA. In case of Swarm-C, no clear anomalies associated with the USA event. Furthermore, Swarm-A, -B and C have abnormal post-seismic PD, STEC and ET responses to the Mw 6.7 Turkey EQ in the form intensive perturbations beyond the upper bound. We also study the atmospheric data over the epicenters in the form of Outgoing Longwave Radiation (OLR), Relative Humidity (RH), Surface Temperature (ST), and Air Temperature (AT) to support the Swarm observations. RH and ST show pre-seismic atmospheric anomalies before the USA EQ in the same anomalous time period as Swarm satellites. While, OLR, ST and AT have post-seismic atmospheric anomalies after the Turkey EQ within 1520-day period. The precursors chain from the lithosphere to the atmosphere, followed by the ionosphere are highlighted at different altitudes. The variations window for Swarm satellites and atmospheric indices are 5 days prior to USA main shock and one month after the Turkish EQ. Moreover, this study also aims to study the caliber of Swarm satellites for indicating seismo-ionospheric irregularities, which need more studies to delineate the LAIC hypothesis for future EQ.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.5194/ACP-2017-411", "year": 2017, "title": "Frequent Ultrafine Particle Formation and Growth in the Canadian Arctic Marine Environment", "abstract": "Abstract. The source strength and capability of aerosol particles in the Arctic to act as cloud condensation nuclei have important implications for understanding the indirect aerosol-cloud effect within the polar climate system. It has been shown in several Arctic regions that ultrafine particle (UFP) formation and growth is a key contributor to aerosol number concentrations during the summer. This study uses aerosol number size distribution measurements from ship-board measurement expeditions aboard the research icebreaker CCGS Amundsen in the summers of 2014 and 2016 throughout the Canadian Arctic to gain a deeper understanding of the drivers of UFP formation and growth within this marine boundary layer. UFP number concentrations (diameter > 4 nm) in the range of 101104 cm3 were observed across the two seasons, with concentrations greater than 103 cm3 occurring more frequently in 2016. Higher concentrations in 2016 were associated with UFP formation and growth, with events occurring on 41 % of days, while events were only observed on 6 % of days in 2014. Assessment of relevant parameters for aerosol nucleation showed that the median condensation sink in this region was approximately 1.2 h1 in 2016 and 2.2 h1 in 2014, which lie at the lower end of ranges observed at even the most remote stations reported in the literature. Apparent growth rates of all observed events in both expeditions averaged 4.3 4.1 nm h1, in general agreement with other recent studies at similar latitudes. Higher solar radiation, lower cloud fractions, and lower sea ice concentrations combined with differences in the developmental stage and activity of marine microbial communities within the Canadian Arctic were documented and help explain differences between the aerosol measurements made during the 2014 and 2016 expeditions. These findings help to motivate further studies of biosphere-atmosphere interactions within the Arctic marine environment to explain the production of UFP and their growth to sizes relevant for cloud droplet activation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.18520/CS/V114/I12/2504-2512", "year": 2018, "title": "Studies of forest fire induced changes in atmosphere over Uttarakhand, India, using space based observations and model simulations", "abstract": "The northern Indian state of Uttarakhand had witnessed an episode of intense forest fire during April-May 2016. The present study analyses the changes in trace gas and other atmospheric constituents induced by the forest fire using satellite data. The study reveals elevated levels of CO, NO2, ozone and aerosol optical depth (AOD) over the affected region. Higher levels of CO are observed at altitudes of 2-3 km. The column amount of CO has almost doubled from mean background values, whereas NO2 has increased by almost three times to values normally seen over highly polluted cities. Increase in ozone is only moderate and AOD has risen towards the end of the main phase of the fire episode. Weather research and forecasting simulations of wind and planetary boundary layer height are also performed and the results discussed. The study shows the potential of Earth-Observation Satellites to track and monitor such environmental impacts effectively.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.APR.2021.101199", "year": 2021, "title": "Comprehensive characterization of PM2.5 using chemical, optical, and spectroscopic methods during pollution episodes at an urban site in Gwangju, Korea", "abstract": "In this study, PM2.5 samples collected between October 29 and December 23, 2018 at a roadway site in Gwangju, Korea, were comprehensively characterized by chemical, optical, and spectroscopic methods. Aerosol light absorption was observed with a time resolution of 1 min using a dual-spot aethalometer. An Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy analysis was also applied to characterize organic and inorganic components in the PM2.5 samples. Three PM2.5 pollution episodes which exceeded the 24-hr Korean PM2.5 standard (35 g/m3) were classified; Episode I was associated with local air stagnation and long-range transportation of aerosol particles from northeast China and upwind regions; Episode II was affected by Asian dust (AD) particles and local pollution under low relative humidity (RH) conditions; and Episode III was strongly associated with accumulation of local pollution due to very high RH and low wind speed, along with regional transport of aerosol particles from eastern China. The contribution of organic aerosols to PM2.5 was higher during episodes I and II than during episode III, while the contribution of NO3 particles was greater during episode III, possibly due to very high RH and low wind speed conditions. Unexpectedly, SO42 was not an important component of PM2.5 during the three episodes. The light absorption coefficient (bBrC,370) of brown carbon (BrC) at 370 nm was estimated to range from 9 Mm1 during episode II to 14 Mm1 during episode III, but the contribution of bBrC,370 to total aerosol absorption was the lowest during episode III. Multiple linear regression analysis indicated that the contributions of the traffic emissions, biomass burning (BB) emissions, and secondary formation processes to bBrC,370 absorption were, on average, 37, 39, and 14% of the total estimated bBrC,370, respectively, suggesting that primary traffic emissions are an important contributor to BrC absorption at the roadway site. ATR-FTIR analysis showed that aliphatic carbon group (CH), carbonyl group (CO), ammonium, sulfate, and nitrate were identified in all filter samples collected during the three pollution episodes; the corresponding bands had the highest intensities in the filter sample from episode III. However, the presence of mineral dusts related to hydroxyl group (-OH), gypsum, AlAlOH group, CO32, and SO32 were clearly detected at the absorbance bands at 34003700 and 650900 cm1 in the AD sample only (episode II). Furthermore, the absorbance bands observed at 2910 and 2850 cm1 during the pollution episodes were assigned to methylene groups (CH2), which are associated with BB emissions, and the intensities of those bands during pollution episodes were consistent with the concentrations of BB indicators (e.g., levoglucosan and K+). These FTIR method can provide valuable chemical insights into the nature of the organic and inorganic components present in ambient aerosol particles during different pollution episodes.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105924", "year": 2021, "title": "Assessment of the coronavirus disease 2019 (COVID-19) pandemic imposed lockdown and unlock effects on black carbon aerosol, its source apportionment, and aerosol radiative forcing over an urban city in India", "abstract": "A nationwide lockdown was imposed in India due to the Coronavirus Disease 2019 (COVID-19) pandemic which significantly reduced the anthropogenic emissions. We examined the characteristics of equivalent black carbon (eBC) mass concentration and its source apportionment using a multiwavelength aethalometer over an urban site (Ahmedabad) in India during the pandemic induced lockdown period of year 2020. For the first time, we estimate the changes in BC, its contribution from fossil (eBCff) and wood (eBCwf) fuels during lockdown (LD) and unlock (UL) periods in 2020 with respect to 2017 to 2019 (normal period). The eBC mass concentration continuously decreased throughout lockdown periods (LD1 to LD4) due to enforced and stringent restrictions which substantially reduced the anthropogenic emissions. The eBC mass concentration increased gradually during unlock phases (UL1 to UL7) due to the phase wise relaxations after lockdown. During lockdown period eBC mass concentration decreased by 35%, whereas during the unlock period eBC decreased by 30% as compared to normal period. The eBCwf concentrations were higher by 40% during lockdown period than normal period due to significant increase in the biomass burning emissions from the several community kitchens which were operational in the city during the lockdown period. The average contributions of eBCff and eBCwf to total eBC mass concentrations were 70% and 30% respectively during lockdown (LD1 to LD4) period, whereas these values were 87% and 13% respectively during the normal period. The reductions in BC concentrations were commensurate with the reductions in emissions from transportation and industrial activities. The aerosol radiative forcing reduced significantly due to the reduction in anthropogenic emissions associated with COVID-19 pandemic induced lockdown leading to a cooling of the atmosphere. The findings in the present study on eBC obtained during the unprecedented COVID-19 induced lockdown can provide a comprehensive understanding of the BC sources and current emission control strategies, and thus can serve as baseline anthropogenic emissions scenario for future emission control strategies aimed to improve air quality and climate.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1080/07055900.2021.1995317", "year": 2021, "title": "Nocturnal Rainfall East of the Antilles Islands", "abstract": "We analyze nocturnal rainfall caused by the interaction of trade winds and land breezes on the windward flank of the islands of Guadeloupe, Dominica, and Martinique of the eastern Caribbean Antilles. Climatology for the 20002019 period and a nocturnal rainfall case study 89 February 2018 are supplemented by modern 525 km hourly resolution satellite and reanalysis products and station measurements that describe the diurnal cycle around the islands. Mean trade winds of 7 m s1 decelerate upstream, U/x less than 105 s1, causing an increase in warm-cloud rainfall from 2 to 4 mm d1 between 03:30 and 06:30 local time (local time is UTC-4). The incoming airflow has a characteristic Froude number less than 1 and stagnates on the windward slopes of these volcanic islands. Nocturnal land breezes spread toward the east coast about one-third of the time.Additional work considers whether airsea interactions play a role. Low salinity and wave-induced turbulence to the east of the Antilles add buoyancy and moisture to the atmospheric boundary layer. Yet areas of low turbidity encircling the east Antilles suggest that nocturnal airflow creates a divergent cushion around Guadeloupe, Dominica, and Martinique. Thermal and orographic influences merge and rain falls over the eastern flank of the islands, contributing to the water resources.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S11869-021-01127-2", "year": 2021, "title": "Assessment of air quality changes during COVID-19 partial lockdown in a Brazilian metropolis: from lockdown to economic opening of Rio de Janeiro, Brazil", "abstract": "During the COVID-19 pandemic, restrictive measures are taken by several cities around the world, as well as Rio de Janeiro, reducing routine activities in large urban centers and primary pollutant emissions. This study aims to assess air quality during this partial lockdown through O3, CO, and PM10 concentrations and meteorological data collected in five air quality monitoring stations spread over the whole city, considering the substantial changes in city routine. The period evaluated starts in March 2020, when the partial lockdown was decreed, and ends in September 2020, when economic opening ended. Compared with 2019 data, CO concentration reduced significantly, as expected since the main source of these pollutants is vehicular traffic. O3 concentration increased, most probably as a consequence of the reduction in primary pollutants. On the other hand, PM10 concentration did not vary significantly. From June to September, pollutant concentrations increased responding to the economic opening. Thereby, the partial lockdown contributed to improving air quality in Rio de Janeiro City, which means that changes in work format may be an alternative to reduce atmospheric pollution in big cities, since home office contributes to mobility reductions, and consequently to vehicular emissions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S42991-021-00186-3", "year": 2021, "title": "Insular gazelles of the circum-Arabian seas: origin, distribution, dwarfism and taxonomy", "abstract": "The taxonomy of gazelles (Bovidae: Antilopinae) has been debated at length. Many of the species and subspecies were historically discriminated mostly on subtle and individually variable phenotypic differences, often on the basis of few, sometimes controversial museum specimens or captive individuals of uncertain origin. The resulting taxonomic confusion is particularly evident for insular populations, which often show slight phenotypic variations. We systematically review and update the past and present distribution of insular gazelles in the circum-Arabian seas, using the literature and reliable websites. Moreover, in light of the available genetic information, we discuss the taxonomic status of four endemic taxa, two of dwarf size. One or more gazelle species are or were present on 45 islands. The archaeozoological and historical data support an anthropochorous origin of most of these populations as a meat source. Lately, food supplied gazelles have been introduced for cultural reasons on many islands of the Persian Gulf. The nine molecularly studied insular populations show low genetic differentiation from their mainland relatives, which suggests their recent origin. Considering the limited genetic differentiation from the geographically closest continental population, we reassign Nanger soemmerringii debeauxi to the nominotypical subspecies. We advocate phenotypic plasticity, triggered by scarce food resources, as the most likely cause of dwarfism in the gazelles of Dahlak and Farasan archipelagos of the Red Sea. We stress the need to avoid unnecessary taxonomic proliferation before deep integrative research has been carried out, and we highlight the importance of research on phenotypic plasticity in insular gazelles.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1177/0309133319898994", "year": 2020, "title": "Tributary-junction alluvial fan response to an ENSO rainfall event in the El Huasco watershed, northern Chile", "abstract": "Tributary-junction alluvial fans situated at the intersection of confined valleys with <100 km2 tributary catchments are of special interest to evaluate the heterogeneous consequences of extreme rainfall events in arid zones. These fans record the episodic sedimentological behaviour of the hillslope response to rainstorm events within tributary catchments, together with the influence on the main fluvial systems. In this paper, we benefit from the March 2015 event (2326 March 2015), which produced 7546 mm of precipitation over four days in the southern portion of the Atacama Desert. This storm event triggered several debris flows in El Huasco River watershed tributaries and, therefore, tributary-junction alluvial fans received a total of 106 m3 of sediments across 49 activated catchments. We find that the characteristic storm signature across the catchments can be synthetised in a conceptual fan formation model based on field mapping of facies (F1 to F6) present in the fans. The characteristic signature is a record of initially high sediment-to-water flows restricted to the fan environments (mainly debris flows) followed by later, more dilute (mainly hyper-concentrated to fluvial) flows that incise the tributary-junction alluvial fan deposits and link tributary catchments with the main river. These later-stage flood event deposits, locally, are capable of ponding and compartmentalising the main river where the longitudinal connectivity of the tributary-junction catchment is effective. This situation improves tributary-junction fan slope and main-trunk-channel linkages. This approach provides a reference framework for understanding the distribution and routing of effective runoff from similar rainfall events that control the aggradation and incision of the fluvial system, which is of great value when studying past stratigraphic arrangements in these arid alleys.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/978-3-030-75602-4_7", "year": 2021, "title": "Input of Terrestrial Material into Coastal Patagonian Waters and Its Effects on Phytoplankton Communities from the Chubut River Estuary (Argentina)", "abstract": "Riverine and eolian-dust inputs to coastal waters are influenced by both rainfall and land-use (i.e., deforestation, agriculture, urbanization). Transport of sediments and nutrients from rivers to the oceans are well- documented worldwide, and it is of major management concern because coastal ecosystems provide a great variety of products and services to humankind. Episodic, but extreme rainfall or dust-storm events can generate abrupt pulsed riverine/eolian discharge events, thus increasing nutrients and sediments in surface waters. It is expected that they will be intensified in the upcoming decades by global change, but we scarcely know how they could impact on coastal planktonic communities. In this chapter we address the main terrestrial material transported via rivers and winds in Patagonian coastal waters of the South West Atlantic Ocean (SWAO) and their impact on the structure and functioning of phytoplankton communities. The rivers in Patagonia carry not only sewage from the cities that lie on their margins, but also heavy loads of nutrients, due to agricultural and cattle raising activities upstream from their mouths; extreme rainfall events increase these inputs manyfold. Eolic inputs are also important over Patagonia because this area has a strong prevalence of winds from the west, carrying a wide variety of particles that are blown far into the ocean, especially after volcanic eruptions. We used the Chubut river estuary (Patagonia) as a reference coastal ecosystem in the SWAO to assess how riverine and eolic inputs impact on phytoplankton which are the base of one of the most productive fisheries areas of the SWAO. Overall, nutrient inputs of terrestrial origin, improved phytoplankton growth, photosynthesis performance and changed the community structure towards a dominance of mostly nanoplanktonic diatom species . These responses, however, might vary due to the interaction of terrestrial material inputs with other global change drivers such as warming, acidification, vertical mixing or solar ultraviolet radiation.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/GMD-8-549-2015", "year": 2015, "title": "Characterising Brazilian biomass burning emissions using WRF-Chem with MOSAIC sectional aerosol", "abstract": "Abstract. The South American Biomass Burning Analysis (SAMBBA) field campaign took detailed in situ flight measurements of aerosol during the 2012 dry season to characterise biomass burning aerosol and improve understanding of its impacts on weather and climate. Developments have been made to the Weather Research and Forecast model with chemistry (WRF-Chem) model to improve the representation of biomass burning aerosol in the region, by coupling a sectional aerosol scheme to the plume-rise parameterisation. Brazilian Biomass Burning Emissions Model (3BEM) fire emissions are used, prepared using PREP-CHEM-SRC, and mapped to CBM-Z and MOSAIC species. Model results have been evaluated against remote sensing products, AERONET sites, and four case studies of flight measurements from the SAMBBA campaign. WRF-Chem predicted layers of elevated aerosol loadings (520 g sm3) of particulate organic matter at high altitude (68 km) over tropical forest regions, while flight measurements showed a sharp decrease above 24 km altitude. This difference was attributed to the plume-rise parameterisation overestimating injection height. The 3BEM emissions product was modified using estimates of active fire size and burned area for the 2012 fire season, which reduced the fire size. The enhancement factor for fire emissions was increased from 1.3 to 5 to retain reasonable aerosol optical depths (AODs). The smaller fire size lowered the injection height of the emissions, but WRF-Chem still showed elevated aerosol loadings between 45 km altitude. Over eastern cerrado (savannah-like) regions, both modelled and measured aerosol loadings decreased above approximately 4 km altitude. Compared with MODIS satellite data and AERONET sites, WRF-Chem represented AOD magnitude well (between 0.31.5) over western tropical forest fire regions in the first half of the campaign, but tended to over-predict them in the second half, when precipitation was more significant. Over eastern cerrado regions, WRF-Chem tended to under-predict AODs. Modelled aerosol loadings in the east were higher in the modified emission scenario. The primary organic matter to black carbon ratio was typically between 810 in WRF-Chem. This was lower than the western flight measurements (interquartile range of 11.615.7 in B734, 14.724.0 in B739), but similar to the eastern flight B742 (8.110.4). However, single scattering albedo was close to measured over the western flights (0.870.89 in model; 0.860.91 in flight B734, and 0.810.95 in flight B739 measurements) but too high over the eastern flight B742 (0.860.87 in model, 0.790.82 in measurements). This suggests that improvements are needed to both modelled aerosol composition and optical properties calculations in WRF-Chem.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3389/FMARS.2021.695821", "year": 2021, "title": "Summer Heatwave Impacts on the European Kelp Saccharina latissima Across Its Latitudinal Distribution Gradient", "abstract": "Kelps are important foundation species in coastal ecosystems currently experiencing pronounced shifts in their distribution patterns caused by ocean warming. While some populations found at species warm distribution edges have been recently observed to decline, expansions of some species have been recorded at their cold distribution edges. Reduced population resilience can contribute to kelp habitat loss, hence, understanding intraspecific variations in physiological responses across a species latitudinal distribution is crucial for its conservation. To investigate potential local responses of the broadly distributed kelp Saccharina latissima to marine heatwaves in summer, we collected sporophytes from five locations in Europe (Spitsbergen, Bod, Bergen, Helgoland, Locmariaquer), including populations exposed to the coldest and warmest local temperature regimes. Meristematic tissue from sporophytes was subjected to increasing temperatures of +2, +4 and +6C above the respective mean summer temperatures (control, 0C) characteristic for each site. Survival and corresponding physiological and biochemical traits were analyzed. Vitality (optimum quantum yield, Fv/Fm) and growth were monitored over time and biochemical responses were measured at the end of the experiment. Growth was highest in northern and lowest in southern populations. Overall, northern populations from Spitsbergen, Bod and Bergen were largely unaffected by increasing summer temperatures up to +6C. Conversely, sporophytes from Helgoland and Locmariaquer were markedly stressed at +6C: occurrence of tissue necrosis, reduced Fv/Fm, and a significantly elevated de-epoxidation state of the xanthophyll cycle (DPS). The variations in phlorotannins, mannitol and tissue C and N contents were independent of temperature treatments and latitudinal distribution pattern. Pronounced site-specific variability in response to increasing temperatures implies that exceeding a threshold above the mean summer temperature exclusively affect rear-edge (southernmost) populations.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS12101261", "year": 2021, "title": "Landslides Triggered by the May 2017 Extreme Rainfall Event in the East Coast Northeast of Brazil", "abstract": "Given the increasing occurrence of landslides on the East Coast Northeast of Brazil (ECNEB), it is essential to understand its conditions and triggering factors because meteorological anomalies triggered by a landslide will threaten life and property in the region. In this sense, this research aimed to diagnose the meteorological conditions that triggered landslides in the ECNEB in May 2017, evaluate the terrains intrinsic conditions using elevation, slope, and susceptibility parameters and determine critical precipitation thresholds for the city with the highest number of landslide risk areas in the region. A dynamic downscaling experiment was carried out using the Regional Climate Model (RegCM) to verify the ability of this model to represent rainfall over the ECNEB. The results from the intrinsic factors showed that the ECNEB is highly susceptible to landslides with various high-risk sectors for landslides to the population. The extreme rainfall event was associated with the convergence of humidity at low levels over the ocean, which contributed to landslides in the ECNEB, mainly in the State of Pernambuco, where 67 landslides were registered. The RegCM numerical simulation underestimated the high daily rainfall signal seen on the Tropical Rainfall Measuring Mission satellite. It is suggested that sensitivity tests can be performed using other physical parameters to find the best model configuration for the ECNEB. This work recommends that exploring the relationship between precipitation and landslides will provide objective criteria for assessing risk areas by contributing to the predictability of disasters in this region.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.134476", "year": 2020, "title": "Optical properties of dust and crop burning emissions over India using ground and satellite data", "abstract": "Dust storms during the pre-monsoon season (AprilJune) and crop residual burning events during the post-monsoon season (mid-Octobermid-November) are common every year over the Indo-Gangetic plains (IGP). In this paper, we have compared dust storm and crop burning aerosols characteristics for the years 2016, 2017 and 2018 using ground and satellite data. CALIPSO data show that dust layers extended from the ground upto an altitude of about 5 km and the smoke from crop burning upto the height of 2 km. Characteristics of dust and crop burning aerosols show pronounced difference based on Kanpur AERONET data. Dominance of coarse particles (0.615 m) during dust storms (pre-monsoon season), while fine particles (0.050.6 m) dominate during crop residual burning. The spectral variations of single scattering albedo (SSA) during dusty days and crop burning days show low and high fractions of anthropogenic aerosols. We have also observed the impact of dust particles on Himalayan snow (cover, albedo and reflectance) and meteorological parameters (relative humidity and water vapor) on the surface and lower atmosphere using MODIS data and AIRS data at different pressure levels. Pronounced aerosols behaviors of the crop residual burning event coincided with Diwali festival on 3031 October 2016 were observed. Our detailed analysis combining ground and satellite observations provides better understanding of aerosol optical and microphysical properties of dust storms and crop residual burnings. The results will be valuable in monitoring surrounding environment, identifying the emission source and dynamics of dust storms and crop burning emissions over India, especially in the IGP.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41467-021-25850-7", "year": 2021, "title": "Significance of the organic aerosol driven climate feedback in the boreal area", "abstract": "Aerosol particles cool the climate by scattering solar radiation and by acting as cloud condensation nuclei. Higher temperatures resulting from increased greenhouse gas levels have been suggested to lead to increased biogenic secondary organic aerosol and cloud condensation nuclei concentrations creating a negative climate feedback mechanism. Here, we present direct observations on this feedback mechanism utilizing collocated long term aerosol chemical composition measurements and remote sensing observations on aerosol and cloud properties. Summer time organic aerosol loadings showed a clear increase with temperature, with simultaneous increase in cloud condensation nuclei concentration in a boreal forest environment. Remote sensing observations revealed a change in cloud properties with an increase in cloud reflectivity in concert with increasing organic aerosol loadings in the area. The results provide direct observational evidence on the significance of this negative climate feedback mechanism.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3354/AB00746", "year": 2021, "title": "Phytodetrital quality (C:N ratio) and temperature changes affect C and N cycling of the intertidal mixotrophic foraminifer Haynesina germanica", "abstract": "The combination of lower diet quality and increased metabolic rates is assumed to cause cascading effects on organismic C cycling. Future changes in CO2 levels or terrestrial nutrient discharges in marine ecosystems can lead to increased phytoplankton C:N ratios relative to consumer C:N ratios, lowering the quality of the food source. In this study, we compared the single and interactive effects of diet quality and temperature on the feeding behavior and C and N intake and release of a common and abundant intertidal mixotrophic protist, the foraminifer Haynesina germanica. Two batches of artificially produced and dual isotope-labeled (13C/15N) chlorophyte detritus with different C:N ratios (5.6 and 7.1) were fed to the foraminifer at 3 different temperatures (15, 20, 25C). We observed a strong interactive effect of temperature and diet. A very strong increase in feeding rates was observed at 20C for the low-quality food source. Respiration rates of carbon derived from the low-quality diet (C:N ratio of 7.1) were lower than those of the high-quality diets and increased at 25C. This indicates that a high C content of the diet might be of advantage in calcifying mixotrophs, since respired excess C could be advantageous for test calcification. Additionally, respired excess C could be a useful resource of CO2 for kleptoplast photosynthesis and functionality in the mixotrophic lifestyle of H. germanica. Further, the observed effects of diet and temperature could impact nutrient fluxes in the habitat of H. germanica, possibly leading to food-web shifts in the future.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41586-021-03805-8", "year": 2021, "title": "Widespread phytoplankton blooms triggered by 20192020 Australian wildfires", "abstract": "Droughts and climate-change-driven warming are leading to more frequent and intense wildfires13, arguably contributing to the severe 20192020 Australian wildfires4. The environmental and ecological impacts of the fires include loss of habitats and the emission of substantial amounts of atmospheric aerosols57. Aerosol emissions from wildfires can lead to the atmospheric transport of macronutrients and bio-essential trace metals such as nitrogen and iron, respectively810. It has been suggested that the oceanic deposition of wildfire aerosols can relieve nutrient limitations and, consequently, enhance marine productivity11,12, but direct observations are lacking. Here we use satellite and autonomous biogeochemical Argo float data to evaluate the effect of 20192020 Australian wildfire aerosol deposition on phytoplankton productivity. We find anomalously widespread phytoplankton blooms from December 2019 to March 2020 in the Southern Ocean downwind of Australia. Aerosol samples originating from the Australian wildfires contained a high iron content and atmospheric trajectories show that these aerosols were likely to be transported to the bloom regions, suggesting that the blooms resulted from the fertilization of the iron-limited waters of the Southern Ocean. Climate models project more frequent and severe wildfires in many regions13. A greater appreciation of the links between wildfires, pyrogenic aerosols13, nutrient cycling and marine photosynthesis could improve our understanding of the contemporary and glacialinterglacial cycling of atmospheric CO2 and the global climate system.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1134/S1028334X21090178", "year": 2021, "title": "Relationship of the Ozone Mini-Hole Over Siberia in January 2016 to Atmospheric Blocking", "abstract": "Using satellite data and reanalysis data, the characteristics and mechanisms of the formation of an ozone mini-hole in the atmosphere over Siberia in the winter of 20152016 have been investigated. The relationship between the regional negative anomaly of the total ozone content (TOC), reaching 140 Dobson units, with atmospheric blocking was established. The TOC anomaly was mainly due to a decrease in the ozone content in the lower stratosphere, reaching 50% near the 70 hPa level. With the key contribution of atmospheric dynamic processes to the formation of the ozone mini-hole, the possibility of the contribution of ozone destruction in heterogeneous reactions on the surface of polar stratospheric clouds, due to a strong decrease in temperature in the stratosphere above the blocking region, was noted.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3389/FENVS.2021.681703", "year": 2021, "title": "The Influence of Climate Change on River Corridors in Drylands: The Case of the Tehuacan-Cuicatlan Biosphere Reserve", "abstract": "The Tehuacan-Cuicatlan Biosphere Reserve, Mexico (TCBR) is the southernmost arid or semi-arid zone with the highest biodiversity in North America and is a UNESCO World Heritage site. Two main hydrographic streams cross the TCBR, the Salado River (an endogenous river) and the Grande River (an exogenous river). This study investigated temperature anomalies over the past 40 years. We analyzed potential differences between sub-basins and riparian areas on both streams using various indices, namely the Global Warming Index (GWI), Normalized Difference Vegetation Index (NDVI), Normalized Difference Water Index (NDWI), and Normalized Difference Drought Index (NDDI), and analyzed the potential relationship of these indices with climate change. Time series of satellite-based precipitation (June 2000December 2020) and air temperature (January 1980December 2020) were analyzed. A set of Landsat 8 OLI TIRS imagery from the driest and wettest months (20132020) was used to estimate NDVI, NDWI, and NDDI. These indices were evaluated separately for the sub-basins and river corridors in the dry and rainy seasons. The precipitation records indicate that in the Grande river sub-basin, precipitation is higher than in the Salado river sub basin. Normalized temperature anomalies and the GWI suggest a warming trend from 1994 to 2020, increasing up to 0.86C in the Salado River and 0.52C in the Grande River. The Grande and Salado sub basins showed significant differences between dry and wet seasons for each index (NDVI, NDWI, and NDDI). A Discriminant Analysis showed that the Salado sub-basin and the Salado River corridor are associated with severe drying conditions in the dry season (highest NDDI values). In the wet season, the Grande River corridor showed intermediate values of NDVI and NDWI but low values of NDDI. The Grande River corridor in the dry season was characterized by intermediate values of NDVI, NDWI, and NDDI. These river corridors provide environmental services in a trade-off with the stream and should be considered biodiversity hotspots. Due to the accentuated warming trend and the lowest precipitation, the Salado River sub-basin showed desertification signs associated with climate change. Both the Salado and the Grande River corridors showed resilience strategies to face climatic conditions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/S41598-021-96752-3", "year": 2021, "title": "Tropical cyclones shape mangrove productivity gradients in the Indian subcontinent", "abstract": "Recent literature on the impact of cyclones on mangrove forest productivity indicates that nutrient fertilizations aided by tropical cyclones enhance the productivity of mangrove forests. We probe the implications of these predictions in the context of Indian mangroves to propose potential future directions for mangrove research in the subcontinent. First, we look at the time series trend (20002020) in satellite-derived gross primary productivity (GPP) datasets for seven mangrove forests across the countrys coastline. Second, we compare seasonal changes in soil nutrient levels for a specific site to further the arguments proposed in the literature and investigate the role of potential drivers of mangrove productivity. We find overall increasing trends for GPP over the past two decades for all seven mangrove sites with seasonal fluctuations closely connected to the tropical storm activities for three sites (Bhitarkanika, Pichavaram, and Charao). Additionally, organic carbon and nitrogen levels showed no significant trend, but phosphorus levels were higher during the post-monsoon-winter period for Bhitarkanika. Our findings expand the predictions of previous studies that emphasized the role of storm-induced nutrient fluxes and freshwater supply as primary drivers of productivity gradients in mangroves. Our study provides insights on how mangrove productivity may change with fluctuating frequency and magnitude of cyclones under a changing climate, implying the need for more mechanistic studies in understanding the long-term impact on mangrove productivity in the region.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCS.2021.103336", "year": 2021, "title": "Impact of COVID-19 induced lockdown on land surface temperature, aerosol, and urban heat in Europe and North America", "abstract": "The outbreak of SARS CoV-2 (COVID-19) has posed a serious threat to human beings, society, and economic activities all over the world. Worldwide rigorous containment measures for limiting the spread of the virus have several beneficial environmental implications due to decreased anthropogenic emissions and air pollutants, which provide a unique opportunity to understand and quantify the human impact on atmospheric environment. In the present study, the associated changes in Land Surface Temperature (LST), aerosol, and atmospheric water vapor content were investigated over highly COVID-19 impacted areas, namely, Europe and North America. The key findings revealed a large-scale negative standardized LST anomaly during nighttime across Europe (0.11 C to 2.6 C), USA (0.70 C) and Canada (0.27 C) in MarchMay of the pandemic year 2020 compared to the mean of 20152019, which can be partly ascribed to the lockdown effect. The reduced LST was corroborated with the negative anomaly of air temperature measured at meteorological stations (i.e. 0.46 C to 0.96 C). A larger decrease in nighttime LST was also seen in urban areas (by 12 C) compared to rural landscapes, which suggests a weakness of the urban heat island effect during the lockdown period due to large decrease in absorbing aerosols and air pollutants. On the contrary, daytime LST increased over most parts of Europe due to less attenuation of solar radiation by atmospheric aerosols. Synoptic meteorological variability and several surface-related factors may mask these changes and significantly affect the variations in LST, aerosols and water vapor content. The changes in LST may be a temporary phenomenon during the lockdown but provides an excellent opportunity to investigate the effects of various forcing controlling factors in urban microclimate and a strong evidence base for potential environmental benefits through urban planning and policy implementation.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1007/S11869-021-01091-X", "year": 2021, "title": "Long-term spatial and temporal variations of aerosol optical depth during 20002020 over Zambia, southcentral Africa", "abstract": "The study aimed at using Moderate Resolution Imaging Spectroradiometer (MODIS-Terra) to investigate long-term spatial and temporal aerosol variations over Zambia during 20002020. Based on data availability, ground truthing for MODIS-Terra was done over Mongu in western Zambia using Aerosol Robotic Network (AERONET) data for 20012009. The correlation coefficient between MODIS-Terra and AERONET is 0.42 and statistically significant at 95% confidence level. The aerosol optical depth at 550nm (AOD550) and Angstrom exponent (AE470-870) annual mean spatial distribution indicates high and moderate to low patterns explaining distinct features of aerosol loadings from different areas over Zambia. Generally, the AOD550 and AE470-870 spatial gradient values increase from southern to northern Zambia explaining fine mode particles mainly produced by local intensive anthropogenic and urban/small and large-scale industrial emission activities in the cities. Seasonal climatology reveals that highest AOD550 is observed during SON, followed by JJA, DJF, with the lowest recorded during MAM. It is also observed from AE470-870 that fine particles are prominent during JJA and SON. The insignificant decreasing (increasing) trend of AOD550 is revealed over Mwinilunga, Misamfu, Mfuwe, Choma, and Kabwe (Mongu). Further results showed that fire hotspot density intensifies over central parts of Africa, including Zambia from June to November. Moreover, the 5-day air mass back trajectory analysis suggests that aerosol sources over Zambia are associated with short- and long-distance ranges from East Africa, Congo Basin, Madagascar, and Atlantic and Indian oceans with diverse transport pathways in different seasons. These findings may help enhance a better understanding of climatic effects and atmospheric aerosol sources in Zambia.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2021.1957513", "year": 2021, "title": "A machine learning approach for spatiotemporal imputation of MODIS chlorophyll-a", "abstract": "The Moderate Resolution Imaging Spectroradiometer (MODIS) level-3 chlorophyll-a (Chl-a) product is one of the widely used ocean colour products that is often used for water quality monitoring of marine ecosystems. However, this product includes a large amount of missing data due to high surface reflectance and cloudy conditions that inevitably affect its suitability for spatiotemporal analysis of water quality. The objective of this study was to compare four Machine Learning (ML) techniques including K-nearest neighbour (KNN), Support Vector Regression (SVR), Random Forest Regression (RFR), and Artificial Neural Network (ANN) with well-known Data Interpolation Empirical Orthogonal Function (DINEOF) method for spatiotemporal missing imputation of MODIS Chl-a. The Southern Caspian Sea, which has a high Chl-a concentration, was selected as the case study. A cross-validation approach ranging missing data ratio from 0.1 to 0.8 was implemented to investigate the optimal parameters of the models and compare their performance for missing imputation. The results indicated that all ML models, except KNN, outperformed the DINEOF method for missing imputation of MODIS Chl-a. The SVR with the highest accuracy and the lowest variability of errors had the best performance among the five competing models, while the KNN showed the worst performance. The main reason for the better accuracy of the SVR than the other models is its structural risk minimization procedure that leads to the better generalization of the SVR model. The current results showed that the ML techniques used in the current study, the SVR in particular, are able to produce reliable imputations of the MODIS Chl-a missing data and can be a useful tool in water quality monitoring of marine ecosystems.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.JMARSYS.2021.103634", "year": 2021, "title": "Biological carbon pump efficiency enhanced by atmospheric dust deposition in the North Pacific Subtropical Gyre", "abstract": "We examine the flux and composition of sinking particles collected at 4500 m depth in the southeastern part of the North Pacific Subtropical Gyre (NPSG) from August 2011 to June 2012. Satellite-derived net primary production was higher in JanuaryMay 2012 compared with the rest of the study period. Both the biogenic and lithogenic particle fluxes were significantly higher in spring (MarchMay 2012) than at other times. The export efficiency via the transfer of produced organic carbon to the deep ocean interior (i.e., carbon sequestration) doubled during this time. Two prominent particle flux peaks were observed in March and May 2012, coinciding with the atmospheric dust-deposition peaks within the temporal resolution of the data. Coincident increases in the biogenic and lithogenic particle fluxes suggest that dust deposition in the NPSG enhances the biological carbon-pump efficiency. Strong coupling between the particulate organic carbon and biogenic opal fluxes implies that nutrient supply via atmospheric dust deposition stimulated diatom growth in this area. Dust deposition during the productive season therefore plays an important role in carbon sequestration.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1080/2150704X.2021.1957509", "year": 2021, "title": "Long term trend in aerosol direct radiative effects over Indian Ocean region from multi- satellite observations", "abstract": "Long-term (20002020) trend in aerosol optical depth (AOD) and the associated radiative effect over Indian Ocean region (Arabian Sea and Bay of Bengal) during winter time south Asian outflow is investigated using multi-satellite data. Analysis revealed a statistically significant increasing trend of 0.01 year1 over the study regions. This study revealed that aerosols are confined within 2 km from ocean surface, and the trend in columnar AOD is significantly modulated by aerosol loading at higher altitudes. Although there has been no significant change in aerosol direct radiative forcing efficiency, the significant enhancement in AOD over the study region has induced an increase in cooling at the top of the atmosphere by 0.1 to 0.2 W m2 year1.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.46488/NEPT.2021.V20I03.004", "year": 2021, "title": "The Increasing Trend of Black Carbon and Organic Carbon in Jordan During the Period of 2007 to 2018", "abstract": "During the last decades, carbonaceous aerosol extinctions such as black carbon and organic carbon\nextinctions exhibit an increasing trend across the globe. Measurements of carbonaceous aerosol in\nJordan were done using satellite data during the period 2007 to 2018. These measurements were done\nin four locations of Jordan - Irbid in the north, Amman and Az-Zarqa in the middle, and Maan in the\nsouth. Black carbon extinction in Jordan increased slightly (slope = 0.0001) during this period, while\norganic carbon extinction increased slightly (slope = (0.7 10) x10 -5 ) in three locations and decreased\nslightly in one location (Irbid location (slope = -2x10 -5 )). Organic carbon extinction measurements were\ngreater than black carbon extinction measurements in all locations with varying ratios depending on the\nlocation of the measurements. Black carbon and organic carbon scattering measurements have the\nsame behavior as extinction, with larger values in the north and smaller values in the south. Scattering\nvalues of organic carbon are larger than black carbon scattering values. Scattering values of organic\ncarbon increased slightly in all locations (slope = 0.0001) while scattering values of black carbon\ndecreased in three locations (Irbid, Amman, and Maan) and increased in one location (Az-Zarqa).\nColumn mass density and surface mass concentration measurements show that organic carbon had\nlarger values than black carbon in all locations besides that both organic carbon and black carbon had\nvalues decreasing when we go from north to south.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS12091140", "year": 2021, "title": "Extreme Aerosol Events at Mesa Verde, Colorado: Implications for Air Quality Management", "abstract": "A significant concern for public health and visibility is airborne particulate matter, especially during extreme events. Of most relevance for health, air quality, and climate is the role of fine aerosol particles, specifically particulate matter with aerodynamic diameters less than or equal to 2.5 micrometers (PM2.5). The purpose of this study was to examine PM2.5 extreme events between 1989 and 2018 at Mesa Verde, Colorado using Interagency Monitoring of Protected Visual Environments (IMPROVE) monitoring data. Extreme events were identified as those with PM2.5 on a given day exceeding the 90th percentile value for that given month. We examine the weekly, monthly, and interannual trends in the number of extreme events at Mesa Verde, in addition to identifying the sources of the extreme events with the aid of the Navy Aerosol Analysis and Prediction (NAAPS) aerosol model. Four sources were used in the classification scheme: Asian dust, non-Asian dust, smoke, and other. Our results show that extreme PM2.5 events in the spring are driven mostly by the dust categories, whereas summertime events are influenced largely by smoke. The colder winter months have more influence from other sources that are thought to be largely anthropogenic in nature. No weekly cycle was observed for the number of events due to each source; however, interannual analysis shows that the relative amount of dust and smoke events compared to other events have increased in the last decade, especially smoke since 2008. The results of this work indicate that, to minimize and mitigate the effects of extreme PM2.5 events in the southwestern Colorado area, it is important to focus mainly on smoke and dust forecasting in the spring and summer months. Wintertime extreme events may be easier to regulate as they derive more from anthropogenic pollutants accumulating in shallow boundary layers in stagnant conditions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105803", "year": 2021, "title": "Spatial and temporal variation of aerosol optical depths over six major cities in Bangladesh", "abstract": "The Aerosol Optical Depth (AOD) is a crucial parameter for assessing aerosol content and determining the level of air pollution. In this study, we represent almost seven years' aerosol optical behavioral patterns of six major cities in Bangladesh with emphasis on trends, seasonal variations, sources characterization, comparison between ground (AERONET) and satellite (MODIS Terra and Aqua) measurements, and relation with particulate matter (PM). High AOD values (>0.70) were obtained in most of the western parts of the country in all seasons. Decreasing patterns were observed from northwest to southeast. Average values of AOD for Dhaka, Chattagram, Rajshahi, Khulna, Barishal, and Sylhet were 0.71 0.08, 0.50 0.08, 0.78 0.06, 0.72 0.14, 0.64 0.08, 0.60 0.07 (Terra), and 0.59 0.07, 0.48 0.05, 0.69 0.08, 0.64 0.12, 0.56 0.05, 0.56 0.07 (Aqua), respectively. AERONET AODs at 870, 500, and 340 nm, and Angstrom Exponent (AE440870) values for Dhaka city were 0.40, 0.78, 1.06, and 1.18, respectively. Mean Absolute Error (MAE), Root Mean Square Error (RMSE), and Correlation coefficient (r) values were 0.23, 0.30, 0.64 (Terra) and 0.12, 0.29, 0.76 (Aqua), respectively. Both PM2.5 and PM10 were well correlated with all AODs but weakly correlated with AE. AODs, AE, and PM were negatively associated with meteorological variables such as rainfall, relative humidity, wind speed, and temperature. Anthropogenic and biomass burning aerosols were dominated in all four seasons, but dust and mixed type aerosols were only dominated in pre-monsoon and monsoon seasons. This research would help researchers further know the nature of atmospheric aerosols and how they affect seasonal patterns.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.GEOMORPH.2021.107912", "year": 2021, "title": "A closer look at factors governing landslide recovery time in post-seismic periods", "abstract": "Earthquakes increase landslide susceptibility in post-seismic periods. The time required for restoring pre-earthquake susceptibility levels is defined as landslide recovery time. Overall, stronger earthquakes are associated with relatively long recovery times in the literature. However, the seismic effect does not explain the whole process. This paper provides insight into factors governing this process. We hypothesize that the dominant post-seismic landsliding process (i.e., new or remobilized landslides), which is governed by the interactions between co-seismic landslide deposits and seismotectonic, morphologic and climatic conditions of a site, is the key to understand the physics behind the landslide recovery time. To test this argument, we analyze 11 earthquake-affected areas associated with seismic variables (i.e., earthquake magnitude and peak ground acceleration) and four environmental factors: (1) the fraction of area affected by co-seismic landslides (FAAL), (2) local relief, (3) average daily precipitation of extreme events (mm/day) and (4) rainfall seasonality. Our findings show that in areas with limited co-seismic landslide deposits (FAAL ~1%), then remobilization of material takes the role of the dominant mechanism and recovery may take longer than a year.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S41748-021-00218-5", "year": 2021, "title": "Prevalence and Associated Risk Factor of COVID-19 and Impacts of Meteorological and Social Variables on Its Propagation in Punjab, Pakistan", "abstract": "The current study identifies the spatial distribution of COVID-19 cases and its association with meteorological and social variables in Punjab (densely populated province of Pakistan). To identify the COVID-19 propagation, the weekly growth, recovery, and deaths rate have also been calculated. The geographic information system (GIS) has used to determine COVID-19 impacts on gender (male/female), age groups, and causalities over an affected population (km2) for the period of 11th March to 12th August, 2020 in each district of province. Our results show that 43 peak days (where daily positive cases were above 900) have been observed in Punjab during 27th May to 8th July, 2020. The high population density districts, i.e., Lahore and Islamabad, have been affected (five persons per square kilometers) due to COVID-19, whereas the maximum death tolls (> 50 persons per millions) have also been observed in these urban districts. The meteorological variables (temperature, humidity, heat index, and ultraviolet index) show negative significant relationship to basic reproduction number (R0), whereas daily COVID-19 cases are positively correlated to aerosols concentration at 95% confidence level. The government intervention (stringency index) shows a positive impact to reduce the COVID-19 cases over the province. Keeping in view the COVID-19 behavior and climatology of the region, it has been identified that the COVID-19 cases may likely to increase during the dry period (high concentration of aerosols) i.e., OctoberDecember, 2020 and post-spring season (April to June), 2021 in urban areas of Pakistan. This study provides an overview on districts vulnerability that would help the policy makers, health agencies to plan their activities to reduce the COVID-19 impacts.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSRES.2021.105793", "year": 2021, "title": "Dust and tropical PMx aerosols in Cape Verde: Sources, vertical distributions and stratified transport from North Africa", "abstract": "We investigated the sources and processes affecting the vertical distribution of tropical PMx aerosols (particulate matter -PM- smaller than 10, 2.5 and 1 m, PM10, PM2.5 and PM1, respectively) in the low troposphere of Santo Antao and Sao Vicente islands, in Cape Verde archipelago, a region where a better understanding of aerosols is needed due to their involvement in tropical meteorology and their impact on air quality, ocean and climate. We found that local sources had a low-scale impact. From transect measurements at ground level, we found that PMx levels were predominantly low, except near to PMx sources, where distinctive PM1 / PM2.5 ratios were measured, linked to vehicle exhaust (0.96), biomass burning (0.67) and Cape Verdean dust (0.36) emissions. The depth of the marine boundary layer (MBL) and the vertical distributions of PMx showed wide variability prompted by meteorological conditions. The trade winds prevailed in the MBL, whereas other airflows were situated above it: North-Atlantic, African easterly airflow and Saharan Air Layer. Under North-Atlantic airflow conditions, the MBL extended to 1400 m above sea level (m.a.s.l.). Above this altitude, PMx concentrations decreased quickly (< 3 g/m3) due to the free troposphere conditions. Under Saharan dust conditions, the MBL was confined to just 70 m.a.s.l., whereas a complex dust stratification was observed above, characterized by alternating dry air layers with high dust loads (PM10 ~ 100 g/m3) and more humid air layers with lower aerosol loads (PM10 ~ 40 g/m3). Within the dry easterly African airflow occurring above the marine stratocumulus typical of the MBL top (placed at 500 m.a.s.l.), we detected layers enriched in hydrophilic aerosols (PM10: ~ 8 g/m3). These were imbedded in relatively humid air (RH ~48%), probably linked to secondary aerosol formation by in-cloud processes in the marine stratocumulus situated below. We found that PMx transport from North Africa, both under dust and dust-free conditions, is associated with complex vertical stratifications, even within the dusty Saharan Air Layer.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S41810-021-00117-2", "year": 2021, "title": "Overview and Seasonality of PM10 and PM2.5 in Guayaquil, Ecuador", "abstract": "The focus of this study is the assessment of total suspended particles (TSP) and particulate matter (PM) with various aerodynamic diameters in ambient air in Guayaquil, a city in Ecuador that features a tropical climate. The urban annual mean concentrations of TSP (Total Suspended Particles), and particle matter (PM) with various aerodynamic diameters such as: PM10, PM2.5 and PM1 are 31 14 g m3, 21 9 g m3, 7 2 g m3 and 1 1 g m3, respectively. Air mass studies reveal that the city receives a clean Southern Ocean breeze. Backward trajectory analysis show differences between wet and dry seasons. During the dry season, most winds come from the south and southwest, while air masses from the peri urban may contribute as pollutant sources during the wet season. Although mean values of PM10 and PM2.5 were below dangerous levels, our year-round continuous monitoring study reveals that maximum values often surpassed those permissible limits allowed by the Ecuadorian norms. A cluster analysis shows four main paths in which west and southwest clusters account for more than 93% of the pollution. Total vertical column of NO2 shows the pollution footprint is strongest during the dry season, as opposed to the wet season. A microscopic morphological characterization of ambient particles within the city during the wet and the dry season reveals coarse mode particles with irregular and rounded shapes. Particle analysis reveals that samples are composed of urban dust, anthropogenic and organic debris during the dry season while mainly urban dust during the wet season.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/APP11157105", "year": 2021, "title": "Solar Potential in Saudi Arabia for Inclined Flat-Plate Surfaces of Constant Tilt Tracking the Sun", "abstract": "The objective of the present work is to investigate the optimally performing tilt angles in Saudi Arabia of solar panels that follow the daily motion of the Sun. To that end, the annual energy sums are estimated for surfaces with tilt angles in the range 555 at 82 locations covering all Saudi Arabia. All calculations use a surface albedo of 0.2 and a near-real value, too. It is found that tilt angles of 40, 45, and 50, respectively, are optimal for the three recently defined solar energy zones in Saudi Arabia. The variation of the energy sums in each energy zone on annual, seasonal and monthly basis is given for near-real ground albedos; the analysis provides regression equations for the energy sums as functions of time. A map of the annual global inclined solar energy for Saudi Arabia is derived and presented. The annual energy sums are found to vary between 2159 kWhm2year1 and 4078 kWhm2year1. Finally, a correction factor, introduced in a recent publication, is used; it is confirmed that the relationship between the correction factor and either the tilt angle or the ground-albedo ratio has a general application and it may constitute a nomogram.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.15625/2615-9783/16315", "year": 2021, "title": "Monitoring spatial-temporal dynamics of small lakes based on SAR Sentinel-1 observations: a case study over Nui Coc Lake (Vietnam)", "abstract": "For the first time, this study estimates the variation of surface water extent of Nui Coc Lake located in Thai Nguyen province in North Vietnam at high spatial (20 m) and temporal resolution (bi-weekly). The classification methodology was developed based on the use of the Otsu threshold algorithm on the histogram of the backscatter coefficient of the SAR Sentinel-1 signal. Totally, more than 150 SAR Sentinel-1 images have been processed for the 2016-2020 period. Except for extreme drought and flood conditions, the average minimum and maximum of the lakes surface water extent are 17 km2 (in May) and 24 km2 (in September/October), respectively, and Nui Coc Lakes surface water was stable during the last five years. Classification results are in good agreement with the corresponding surface water extent maps derived from free-cloud Sentinel-2 images, with the occurrence map derived from the Landsat-derived Global Surface Water (GSW) product, and with in situ precipitation data. Compared to Sentinel-2, the lakes surface water extent detected from Sentinel-1 is 4-4.5% less. The water occurrence is similar between our results and that derived from the GSW product, but Sentinel-1 data provide more details as its spatial resolution is higher than Landsat. This study clearly shows the great potential of SAR Sentinel-1 data for monitoring small lakes water surface at low costs, especially over tropical regions.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1111/1462-2920.15716", "year": 2021, "title": "Environmental parameters associated with incidence and transmission of pathogenic Vibrio spp.", "abstract": "Vibrio spp. thrive in warm water and moderate salinity, and they are associated with aquatic invertebrates, notably crustaceans and zooplankton. At least 12 Vibrio spp. are known to cause infection in humans, and Vibrio cholerae is well documented as the etiological agent of pandemic cholera. Pathogenic non-cholera Vibrio spp., e.g., Vibrio parahaemolyticus and Vibrio vulnificus, cause gastroenteritis, septicemia, and other extra-intestinal infections. Incidence of vibriosis is rising globally, with evidence that anthropogenic factors, primarily emissions of carbon dioxide associated with atmospheric warming and more frequent and intense heatwaves, significantly influence environmental parameters, e.g., temperature, salinity, and nutrients, all of which can enhance growth of Vibrio spp. in aquatic ecosystems. It is not possible to eliminate Vibrio spp., as they are autochthonous to the aquatic environment and many play a critical role in carbon and nitrogen cycling. Risk prediction models provide an early warning that is essential for safeguarding public health. This is especially important for regions of the world vulnerable to infrastructure instability, including lack of water, sanitation, and hygiene (WASH), and a less resilient infrastructure that is vulnerable to natural calamity, e.g., hurricanes, floods, and earthquakes, and/or social disruption and civil unrest, arising from war, coups, political crisis, and economic recession. Incorporating environmental, social, and behavioural parameters into such models allows improved prediction, particularly of cholera epidemics. We have reported that damage to WASH infrastructure, coupled with elevated air temperatures and followed by above average rainfall, promotes exposure of a population to contaminated water and increases the risk of an outbreak of cholera. Interestingly, global predictive risk models successful for cholera have the potential, with modification, to predict diseases caused by other clinically relevant Vibrio spp. In the research reported here, the focus was on environmental parameters associated with incidence and distribution of clinically relevant Vibrio spp. and their role in disease transmission. In addition, molecular methods designed for detection and enumeration proved useful for predictive modelling and are described, namely in the context of prediction of environmental conditions favourable to Vibrio spp., hence human health risk.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/RS13112231", "year": 2021, "title": "Evaluating Carbon Monoxide and Aerosol Optical Depth Simulations from CAM-Chem Using Satellite Observations", "abstract": "The scope of this work was to evaluate simulated carbon monoxide (CO) and aerosol optical depth (AOD) from the CAM-chem model against observed satellite data and additionally explore the empirical relationship of CO, AOD and fire radiative power (FRP). The simulated seasonal global concentrations of CO and AOD were compared, respectively, with the Measurements of Pollution in the Troposphere (MOPITT) and the Moderate-Resolution Imaging Spectroradiometer (MODIS) satellite products for the period 20102014. The CAM-chem simulations were performed with two configurations: (A) tropospheric-only; and (B) tropospheric with stratospheric chemistry. Our results show that the spatial and seasonal distributions of CO and AOD were reasonably reproduced in both model configurations, except over central China, central Africa and equatorial regions of the Atlantic and Western Pacific, where CO was overestimated by 1050 ppb. In configuration B, the positive CO bias was significantly reduced due to the inclusion of dry deposition, which was not present in the model configuration A. There was greater CO loss due to the chemical reactions, and shorter lifetime of the species with stratospheric chemistry. In summary, the model has difficulty in capturing the exact location of the maxima of the seasonal AOD distributions in both configurations. The AOD was overestimated by 0.1 to 0.25 over desert regions of Africa, the Middle East and Asia in both configurations, but the positive bias was even higher in the version with added stratospheric chemistry. By contrast, the AOD was underestimated over regions associated with anthropogenic activity, such as eastern China and northern India. Concerning the correlations between CO, AOD and FRP, high CO is found during MarchAprilMay (MAM) in the Northern Hemisphere, mainly in China. In the Southern Hemisphere, high CO, AOD, and FRP values were found during AugustSeptemberOctober (ASO) due to fires, mostly in South America and South Africa. In South America, high AOD levels were observed over subtropical Brazil, Paraguay and Bolivia. Sparsely urbanized regions showed higher correlations between CO and FRP (0.70.9), particularly in tropical areas, such as the western Amazon region. There was a high correlation between CO and aerosols from biomass burning at the transition between the forest and savanna environments over eastern and central Africa. It was also possible to observe the transport of these pollutants from the African continent to the Brazilian coast. High correlations between CO and AOD were found over southeastern Asian countries, and correlations between FRP and AOD (0.50.8) were found over higher latitude regions such as Canada and Siberia as well as in tropical areas. Higher correlations between CO and FRP are observed in Savanna and Tropical forests (South America, Central America, Africa, Australia, and Southeast Asia) than FRP x AOD. In contrast, boreal forests in Russia, particularly in Siberia, show a higher FRP x AOD correlation than FRP x CO. In tropical forests, CO production is likely favored over aerosol, while in temperate forests, aerosol production is more than CO compared to tropical forests. On the east coast of the United States, the eastern border of the USA with Canada, eastern China, on the border between China, Russia, and Mongolia, and the border between North India and China, there is a high correlation of CO x AOD and a low correlation between FRP with both CO and AOD. Therefore, such emissions in these regions are not generated by forest fires but by industries and vehicular emissions since these are densely populated regions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1126/SCIADV.ABE4342", "year": 2021, "title": "The geographic disparity of historical greenhouse emissions and projected climate change", "abstract": "One challenge in climate change communication is that the causes and impacts of global warming are unrelated at local spatial scales. Using high-resolution datasets of historical anthropogenic greenhouse emissions and an ensemble of 21st century surface temperature projections, we developed a spatially explicit index of local climate disparity. This index identifies positive (low emissions, large temperature shifts) and negative disparity regions (high emissions, small temperature shifts), with global coverage. Across all climate change projections we analyzed, 99% of the earths surface area has a positive index value. This result underscores that while emissions are geographically concentrated, warming is globally widespread. From our index, the regions of the greatest positive disparity appear concentrated in the polar arctic, Central Asia, and Africa with negative disparity regions in western Europe, Southeast Asia, and eastern North America. Straightforward illustrations of this complex relationship may inform on equity, enhance public understanding, and increase collective global action.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.31857/S0205961420060032", "year": 2020, "title": "Studies of heat fields before strong fields earthquakes in Turkey March 8, 2010 (M = 6.1) and January 24, 2020 (M = 6.7).", "abstract": "Thermal field anomalies during preparation and occurrence of strong earthquakes in Turkey on March 8, 2010 (M = 6.1) and January 24, 2020 (M = 6.7) were studied using satellite data. Temperatures of the surface and the atmosphere's near surface layer, as well as outgoing longwave radiation registered by the AIRS sensor of the Aqua satellite were used for the analysis. The processing results have allowed us to find out that 712 days before the studied seismic events with = 6.1 and = 6.7 magnitudes there appeared positive variations of surface and atmosphere temperatures that set the stage for the formation of outgoing longwave radiation anomalies registered over the North and East Anatolian tectonic faults. The thermal field anomalies detected during the preparation of the earthquakes in Turkey confirm the presence of heat generation effects between the surface and the upper cloud edge. These effects can be used as short-term precursors of strong seismic events that can be registered from space.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S12517-021-07821-W", "year": 2021, "title": "Assessment of dust major ions and suspended heavy metal contents in atmospheric particulate matter of Port Said city, Egypt", "abstract": "Deposited particulate matter (dust fall) was collected in an urban and industrial city, Port Said, Egypt, from March 2018 to February 2019, and analyzed for water-soluble ions. In addition, suspended particulate matter (SPM) was collected from March to August 2018, and the filtrate samples were analyzed for heavy metal concentrations using ICP-OES. The depositional rates of dust fall and SPM in sampling sites were compared with meteorological (e.g., temperature, wind speed and direction) and satellite-based datasets. GIS-based interpolated maps were delineated for concentrations of major ions and heavy metals to determine their spatial and temporal variations within sampling sites. The analyzed anions (meq/L) have the decreasing order: SO42 (5.86) > Cl (4.54) > HCO3 (1.57) > NO3 (0.10) and Ca2+ (4.20) > Na+ (4.00) > Mg2+ (2.10) > K+ (1.51) > NH4+ (0.37) for cations. Low ratios of NO3/SO42 indicate the predominance of stationary pollution sources in Port Said city. The SPM-associated heavy metals (g/m3) have the decreasing order: Fe (2.7) > Cr (1.64) > Ni (1.35) > Pb (1.3) > Cd (0.17). The mean concentration of SPM (258 g/m3) exceeds the European (150 g/m3) and Egyptian (230 g/m3) air quality standards. Statistically, Cd and Cr were positively correlated with Fe (R2 = 0.86), while Pb and Ni were not. Overall, findings show that high rates of dust fall and heavy metals in Port Saids atmosphere can be attributed to urbanization (construction sites), sea-salt spray, and anthropogenic sources (e.g., industrial and vehicle emissions).", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1175/EI-D-17-0009.1", "year": 2018, "title": "Characteristics of Ethiopia Air Chemistry and Its Meteorological Context", "abstract": "The concentration of trace gases and aerosols in Ethiopia is\npoorly characterized due to a limited history of surface measurements. Here,\nsatellite measurements and model estimates of atmospheric composition are\nemployed to understand spacetime distributions in the period 200016. Methane\n(CH 4 ) and carbon monoxide (CO) display high concentrations over the highlands\nand provide a focus for analysis of monthly and daily data. CH 4 emissions from\nlivestock peak at the beginning of the dry season, while CO from biomass burning\nrises at the end of the dry season. The seasonal cycle of dust, aerosol optical depth\n(AOD), and CO 2 is inversely related with CH 4 , while CO closely follows sensible\nheat flux, thus linking drying and rural biomass burning. Stable easterly flow in\nthe dry season accumulates local emissions, so near-surface concentrations of CO\nand CH 4 are high then. The weather pattern underlying an episode of high ni-\ntrogen dioxide (NO 2 ) concentrations was studied. In addition to a stable lapse rate\nand dry anticyclonic weather, midtropospheric subsidence was related to intrusion\nof the northern subtropical jet stream on 2426 December 2010. The wind shadow\nwas cast by the Rift Escarpment limited dispersion, particularly with the dry,\nstable weather conditions. A key outcome of this work is that CH 4 concentrations over Ethiopia are high in global context and have increased .0.1 ppm from 2002\nto 2016; hence, there is a need to improve livestock management and production efficiency.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1051/E3SCONF/202014903011", "year": 2020, "title": "Features of atmospheric disturbances in temperate latitudes before strong earthquakes (M> 7) according to satellite measurements", "abstract": "An ATOVS and MERRA data archive containing\ntemperature values at isobaric levels from 1000 to 50 hPa was formed\nto study the atmospheric effects observed over the foci of two strong\nearthquakes with magnitudes M = 7,3. The first seismic event was\nrecorded on August 19, 1992 in the northern Tien Shan and the second\non November 12, 2017 in the border areas of the Zagros folded\nmountain belt. According to USGS intense aftershock activity in these\nregions began with these seismic events. Using correlation and spectral\nanalysis we studied the vertical profiles of temperature and pressure in\na disturbed atmosphere over seismically active regions. The modified\nanomaly index was calculated at isobaric levels from 500 to 50 hPa and\non its basis the registered temperature anomalies were investigated.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.RENENE.2021.01.126", "year": 2021, "title": "Solar extinction map in Chile for applications in solar power tower plants, comparison with other places from sunbelt and impact on LCOE", "abstract": "Direct normal solar irradiation is a crucial parameter for site selection and design of solar power tower plants. It also has a high impact on economic studies, such as the levelized cost of electricity (LCOE). However, direct solar irradiation can be partially extinguished in its path between heliostats and receivers. Therefore, considering only direct normal solar irradiation in the solar resource assessment for tower plant projects is insufficient and leads to errors. This paper presents an improved methodology to estimate the extinction of radiation in the first 150 m of the lower atmosphere, where solar power tower plants are located. This work also shows the first atmospheric extinction maps, which in this case are elaborated for Chilean territory, and the intercomparison of extinction values with other places of interest in the sunbelt. Chile stands out for having the lowest annual atmospheric extinction values, below 4% for 1 km of slant range, while elsewhere annual losses can reach up to 17%. These values limit the amount of local useful solar resource available directly impacting on the LCOE values calculated for solar tower power plants. A new equation for the calculation of the LCOE considering atmospheric extinction is proposed in this paper.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S42398-021-00166-W", "year": 2021, "title": "Recent advances in satellite mapping of global air quality: evidences during COVID-19 pandemic", "abstract": "There was a significant decline in air pollution in different parts of the world due to enforcement of lockdown by many countries to check the spread of the coronavirus (COVID-19) pandemic. In particular, commercial and industrial activities had been limited globally with restricted air and surface traffic movements in response to social distancing and isolation. Both satellite remote sensing and ground-based monitoring were used to measure the change in the air quality. There was momentous decline in the averaged concentrations of nitrogen dioxide (NO2), carbon dioxide (CO2), sulphur dioxide (SO2), methane (CH4) and aerosols. Many cities across India, China and several major cities in Europe observed strong reductions in nitrogen dioxide levels dropping by around 4050% owing to lockdowns. Similarly, concentrations of SO2 in polluted areas in India, especially around large coal-fired power plants and industrial areas decreased by around 40% as evidenced by the comparative satellite mapping during April 2019 and April 2020. Recent advances in sensors on board various satellites played a significant role in real-time monitoring of emission regimes over various parts of the world. The satellite data is relying upon single scene profusion for real-time air quality measurements, and also using averaged dataset over certain time-period. The daily global-scale remote sensing data of NO2, as measured through the Copernicus Sentinel-5 Precursor Tropospheric Monitoring Instrument (S5p/TROPOMI) of European Space Agency (ESA), indicated exceptional decreases in tropospheric NO2 pollution in urban areas. Similarly, Greenhouse gases Observing Satellite (GOSAT) of Japan Aerospace Exploration Agency, with a repeat cycle of three days helped in assessing the sources and sinks of CO2 and CH4 on a sub-continental scale.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.MARCHEM.2021.103938", "year": 2021, "title": "Dry-deposition of inorganic and organic nitrogen aerosols to the Arabian Sea: Sources, transport and biogeochemical significance in surface waters", "abstract": "Air-to-sea deposition of water-soluble total nitrogen (WSTN) can influence the primary productivity in the coastal oceans. Here, we assessed the concentrations of aerosol inorganic (WSIN: NH4+ + NO3) and WSTN over the Arabian Sea during winter season (SS379:624 December 2018). The mean concentrations of NH4+ (109 83 nmol m3) overwhelm that of NO3 (32 13 nmol m3) and water-soluble organic nitrogen (WSON: WSTN-WSIN: 86 81 nmol m3), and contributing to ~50 31% of WSTN mass. Significant linear relationships of WSON with water-soluble organic carbon and NH4+ with non-sea-salt (nss)-K+ is observed suggesting their common origin from biomass burning and fertilizers. Backward air mass trajectories and satellite-based fire counts further revealed their provenance in the Indo-Gangetic Plain and southern India. The concentration of NO3 moderately correlated with nssCa2+ (dust tracer), indicating heterogeneous reactive uptake on mineral aerosol surface. Despite high concentrations, the deposition fluxes of NH4+ (~9.4 7.1 mol m2 d1) and WSON (7.4 7.0 mol m2 d1) are lower than NO3 (27 11 mol m2 d1) because of their predominant fine nature (i.e., strong correlation with nss-SO42). We also constrained the total annual atmospheric deposition rates of WSIN (0.94 Tg yr1) and WSON (0.08 Tg yr1) to the Arabian Sea during the continental outflow (November-April). The maximum dry-deposition of WSON to the Arabian Sea (0.24 Tg yr1) is twice that of the riverine supply (0.11 Tg yr1), highlighting the significance of aeolian sources. By using Redfield Stoichiometry, the WSTN deposition (2173 mol m2 d1) can account for <5.3% of fixedcarbon by a primary production in the Arabian Sea.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1175/EI-D-20-0004.1", "year": 2021, "title": "Dispersion of Smoke Plumes over South America", "abstract": "AbstractSatellite and reanalysis products are used to study the atmospheric environment, aerosols, and trace gases in smoke plumes over South America in the period 200018. Climatic conditions and fire density maps provide context to link biomass burning across the southern Amazon region (515S, 5070W) to thick near-surface plumes of trace gases and fine aerosols. Intraseasonal weather patterns that underpin greater fire emissions in the dry season (JulyOctober) are exacerbated by high pressure over a cool eastern Pacific Ocean, for example in September 2007. Smoke-plume dispersion simulated with HYSPLIT reveals a slowing of westward transport between sources in eastern Brazil and the Andes Mountains. During cases of thick smoke plumes over southern Amazon, an upper ridge and sinking motions confine trace gases and fine aerosols below 4 km. Long-term warming, which tends to coincide with the zone of biomass burning, is +0.03C yr1 in the air and +0.1C yr1 at the land surface. Our study suggests that weather conditions promoting fire emissions also tend to limit dispersion.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/LNO.11705", "year": 2021, "title": "Diatom response to alterations in upwelling and nutrient dynamics associated with climate forcing in the California Current System", "abstract": "The California Current System displays a strong seasonal cycle in water properties, circulation, and biological production. Interactions of the alongshore current with coastal and topographic features lead to high spatial variability forced by seasonal winds that displace surface coastal water offshore. This process also supplies nutrients to the euphotic zone by Ekman transport and eventually supports phytoplankton blooms typically dominated by diatoms. Here, we investigate the relationship between biogenic silica production and mesoscale upwelling dynamics along the central region of the California Current System between 2013 and 2015, a period affected by a warm anomaly known as the Blob. Changes in the upwelling phenology along California caused by this marine heatwave are investigated using an innovative index and related to patterns of diatom production during upwelling events to evaluate diatom resilience. Based on this new index, we estimated that the nutrient supply to the euphotic zone declined by 50% during the Blob, but the Blob had little impact on local production during individual upwelling events. A statistical analysis evaluating the relationship between production and environmental conditions reveals persistent biological hotspots characterized by high biomass, depleted nutrients, and high specific production rates (up to 0.7 d1) throughout the study period. Lower observed biogenic silica to Chlorophyll a ratios during the Blob suggested a taxonomic shift from siliceous to nonsiliceous phytoplankton and/or lightly silicified diatoms signaling a change at the base of the food chain that could have ramifications for productivity in this eastern boundary coastal upwelling system.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.21839/JAAR.2020.V5.324", "year": 2020, "title": "Spatiotemporal observations of CH4 and CO2 over Iraq using Atmospheric Infrared Sounder (AIRS) data", "abstract": "Methane (CH4) and carbon dioxide (CO2) are the most important greenhouse gases and most important climate forcing agents due to their significant impact on climate, and their concentrations have been increased since the pre-industrial time by 150 and 40 % respectively, basically from fossil fuel combustion and land-use change emissions. In this research, the atmospheric concentration of CH4 and CO2 over Iraq is measured by the Atmospheric Infrared Sounder (AIRS). Time series and time-averaged maps were generated to study and analyse the distribution of CH4 and CO2 concentrations. The results show a significant increase of these two gases with an average increase (3.5 and 5.11 ppbv/ year ) in a rate of (2.69 % and 4 %) for CH4 at SPL 925 hPa and 400 hPa, respectively ; the average increase of CO2 is (1.85 ppm/ year) represent (3.31%) for the whole period. The considerable increase of CH4 and CO2 concentration can affect human healthiness and earth radiative balance. Also, the Satellite observation of AIRS can efficiently show the spatiotemporal variations of CH4 and CO2 for the study area.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-13-837-2013", "year": 2013, "title": "Decadal record of satellite carbon monoxide observations", "abstract": "Abstract. Atmospheric carbon monoxide (CO) distributions are controlled by anthropogenic emissions, biomass burning, transport and oxidation by reaction with the hydroxyl radical (OH). Quantifying trends in CO is therefore important for understanding changes related to all of these contributions. Here we present a comprehensive record of satellite observations from 2000 through 2011 of total column CO using the available measurements from nadir-viewing thermal infrared instruments: MOPITT, AIRS, TES and IASI. We examine trends for CO in the Northern and Southern Hemispheres along with regional trends for Eastern China, Eastern USA, Europe and India. We find that all the satellite observations are consistent with a modest decreasing trend ~ 1 % yr1 in total column CO over the Northern Hemisphere for this time period and a less significant, but still decreasing trend in the Southern Hemisphere. Although decreasing trends in the United States and Europe have been observed from surface CO measurements, we also find a decrease in CO over E. China that, to our knowledge, has not been reported previously. Some of the interannual variability in the observations can be explained by global fire emissions, but the overall decrease needs further study to understand the implications for changes in anthropogenic emissions.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.3389/FRWA.2021.626849", "year": 2021, "title": "Metagenomic Sequencing and Quantitative Real-Time PCR for Fecal Pollution Assessment in an Urban Watershed", "abstract": "Microbial contamination of recreation waters is a major concern globally, with pollutants originating from many sources, including human and other animal wastes often introduced during storm events. Fecal contamination is traditionally monitored by employing culture methods targeting fecal indicator bacteria (FIB), namely E. coli and enterococci, which provides only limited information of a few microbial taxa and no information on their sources. Host-associated qPCR and metagenomic DNA sequencing are complementary methods for FIB monitoring that can provide enhanced understanding of microbial communities and sources of fecal pollution. Whole metagenome sequencing (WMS), quantitative real-time PCR (qPCR), and culture-based FIB tests were performed in an urban watershed before and after a rainfall event to determine the feasibility and application of employing a multi-assay approach for examining microbial content of ambient source waters. Cultivated E. coli and enterococci enumeration confirmed presence of fecal contamination in all samples exceeding local single sample recreational water quality thresholds (E. coli, 410 MPN/100 mL; enterococci, 107 MPN/100mL) following a rainfall. Test results obtained with qPCR showed concentrations of E. coli, enterococci, and human-associated genetic markers increased after rainfall by 1.52-, 1.26-, and 1.11-log10 copies per 100 mL, respectively. Taxonomic analysis of the surface water microbiome and detection of antibiotic resistance genes, general FIB, and human-associated microorganisms were also employed. Results showed that fecal contamination from multiple sources (human, avian, dog, and ruminant), as well as FIB, enteric microorganisms, and antibiotic resistance genes increased demonstrably after a storm event. In summary, the addition of qPCR and WMS to traditional surrogate techniques may provide enhanced characterization and improved understanding of microbial pollution sources in ambient waters.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/S10064-021-02238-X", "year": 2021, "title": "Capturing the footprints of ground motion in the spatial distribution of rainfall-induced landslides", "abstract": "The coupled effect of earthquakes and rainfall is rarely investigated in landslide susceptibility assessments although it could be crucial to predict landslide occurrences. This is even more critical in the context of early warning systems and especially in cases of extreme precipitation regimes in post-seismic conditions, where the rock masses are already damaged due to the ground shaking. Here, we investigate this concept by accounting for the legacy of seismic ground shaking in rainfall-induced landslide (RFIL) scenarios. We do this to identify whether ground shaking plays a role in the susceptibility to post-seismic rainfall-induced landslides and to identify whether this legacy effect persists through time. With this motivation, we use binary logistic regression and examine time series of landslides associated with four earthquakes occurred in Indonesia: 2012 Sulawesi (Mw = 6.3), 2016 Reuleut (Mw = 6.5), 2017 Kasiguncu (Mw = 6.6) and 2018 Palu (Mw = 7.5) earthquakes. The dataset includes one co-seismic and three post-seismic landslide inventories for each earthquake. We use the peak ground acceleration map of the last strongest earthquake in each case as a predisposing factor of landslides representing the effect of ground shaking. We observe that, at least for the study areas under consideration and in a probabilistic context, the earthquake legacy contributes to increase the post-seismic RFIL susceptibility. This positive contribution decays through time. Specifically, we observe that ground motion is a significant predisposing factor controlling the spatial distribution of RFIL in the post-seismic period 110 days after an earthquake. We also show that this effect dissipates within 3 years at most.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1080/2150704X.2021.1903610", "year": 2021, "title": "Impact of COVID-19 lockdown on ground-based airglow observations over India", "abstract": "Airglow emissions which originate from the mesospheric and thermospheric altitudes have been routinely being monitored at Kolhapur (16.8 N, 74.2 E), Maharashtra, India, using ground base remote sensing imagers. We note that the observable amplitudes of very small-scale waves during April 2020 were significantly smaller than the regular observations. We investigate the reason for these low observable amplitudes. It is noted that drastic improvement in the quality of images was due to better contrast, which is attributed to significant reduction in greenhouse gases and aerosol loading in the atmosphere by the complete shutdown of local man-made emissions. Results suggest that lockdown had an important repercussion on the visibility through the improved air quality and thus better viewing conditions, which were reflected in the remotely sensed observations made with airglow imager.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1007/S00024-021-02701-6", "year": 2021, "title": "Surface Urban Heat Island (SUHI) Over Riverside Cities Along the Gangetic Plain of India", "abstract": "Rapid urbanisation in India has led to increased land use and energy demand, and the consequent uncontrolled development and increased human-induced activities are changing the micrometeorology and the local environment. Of late, the surface urban heat island (SUHI) effect is quite evident in India. It is known that river banks are where the most densely populated cities can be found around the globe, and the River Ganga (Ganges) in India is no exception. Town/cities located over the Gangetic Plain are witnessing a fast urbanisation, and associated perturbation is taking place in the micro/meso-scale meteorology/environment. Discussion about the influence of the river on the SUHI and dynamics over different cities along a single major river is needed, and therefore this study is undertaken to investigate the SUHI effect on riverside towns/cities over the Gangetic Plain, India. For this purpose, the observation data for the period of 20012014 from the Terra-MODIS satellite are used. The study quantifies the land surface temperature (LST) under different zones namely urban, suburban, and rural, delineated on the basis of International Geosphere Biosphere Programme-Land Cover (IGBP-LC) products. The intensity and trend of SUHI are measured as an indicator of environmental and micro-climate change. The study found a prevailing regime of nighttime SUHI intensity (SUHII) as well as the daytime formation of SUHI. The interaction of the wind blowing from the river and other land cover to towns/cities was examined with respect to the SUHII of Kanpur and Patna and was found to be quite important.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.147168", "year": 2021, "title": "Temperature patterns along an arid coastline experiencing extreme and rapid urbanization, case study: Dubai", "abstract": "Today more than one billion people are living in coastal regions, and coastal urbanization is rapidly growing worldwide. Here, we explore the impact of an extreme and rapid coastal urbanization on temperature patterns, based on MODIS data. We study Dubai, one of the fastest growing cities in the world over the last two decades. Dubai's urbanization centers along its coastline in land, massive skyscrapers and infrastructure have been built, while in sea, just nearby, unique artificial islands have been constructed. Studying the coastline during the years of intense urbanization, we show that the coastline exhibits surface urban heat island characteristics, where the urban center experiences higher temperatures, by as much as 2.5 C and more, compared to the adjacent less urbanized zones. During development, the coastal surface urban heat island has nearly doubled its size, expanding towards the newly developed areas. This newly developed zone also exhibits the largest temperature trend along the coast of over 0.1 C/year on average. In addition, an opposite linear relation was found between the surface temperature and albedo trends. In sea, temperature decreases were observed, particularly over the artificial islands, exceeding 0.1 C/year, in one of them. The positive trends in land along with the negative trends in sea decreased the coastal sea-land temperature gradient by up to about 30% in only 12 years, which also decreased the land breeze intensity. The findings shown here directly affect the local coastal population and ecosystem, exacerbate the thermal comfort, and add additional burden to this area, which is already considered as one of the warmest in the world.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.BIOCON.2020.108766", "year": 2020, "title": "Evaluating Antarctic marine protected area scenarios using a dynamic food web model", "abstract": "Marine protected areas, especially when they are or include no-take zones, can support conservation objectives by creating an area where marine organisms are protected from human disturbances, particularly fishing. The coast of the Antarctic continent is the only habitat of the iconic Adelie penguin, whose main diet is Antarctic krill. Current threats to Adelie Penguins, other Antarctic krill predators and Antarctic krill itself include sea-ice loss as a result of climate change and krill fishing. We use a spatially and temporally dynamic food web model of the region surrounding the Western Antarctic Peninsula to evaluate the potential impacts of various marine protected area scenarios in the context of climate change. We examine the effects of sustained sea-ice loss on krill and seven monitored krill predators. We evaluate four marine protected area scenarios given two scenarios that describe future changes in sea ice and three scenarios that describe future changes in krill fishing effort. Our results indicate that establishing no-take zones where krill might aggregate in the future and where some krill predators forage could positively affect biomass accumulation of krill and the predators. No-take zones may be particularly important for enhancing the resilience of species that have recently experienced population decline and ensuring positive outcomes from establishing a marine protected area in the region. Our simulations suggest that establishing protected areas in the right locations can play an important role in mitigating the negative effects of climate change on iconic species that many people want to conserve.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1038/S41558-020-0714-3", "year": 2020, "title": "Dirty air offsets inequality", "abstract": "Atmospheric aerosols have probably masked a significant portion of the greenhouse-gas-induced warming so far. Research now shows that this also may have masked some of the worlds increasing economic inequality.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-2020-848", "year": 2020, "title": "Fifty-six years of Surface Solar Radiation and Sunshine Duration at the Surface in Sao Paulo, Brazil: 19612016", "abstract": "Abstract. Fifty-six years (19612016) of daily surface downward solar irradiation, sunshine duration, diurnal temperature range and the fraction of the sky covered by clouds in the city of Sao Paulo, Brazil, were analyzed. The main purpose was to contribute to the characterization and understanding of the dimming and brightening effects on solar global radiation in this part of South America. As observed in most of the previous studies worldwide, in this study, during the period between 1961 up to the early 1980's, more specifically up to 1983, a negative trend in surface solar irradiation was detected in Sao Paulo, characterizing the occurrence of a dimming effect. A similar behavior, a negative trend, was also observed for sunshine duration and the diurnal temperature range, the three variables in opposition to the trend in the sky cover fraction. However, a brightening effect, as observed in western industrialized countries in more recent years, was not observed. Instead, for surface downward irradiation, the negative trend persisted and still in consonance to the cloud cover fraction increasing trend. The trends for sunshine duration and the diurnal temperature range, by contrast, changed signal. Some possible causes for the discrepancy were discussed, such as the frequency of fog occurrence, urban heat island effects, aerosol changes and greenhouse gas concentration increase. Future studies on aerosol effect are encouraged, particularly with higher temporal resolution as well as modeling studies, to better analyze the contribution of each possible causes.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S11356-020-11248-3", "year": 2020, "title": "Spatio-temporal assessment of ambient air quality, their health effects and improvement during COVID-19 lockdown in one of the most polluted cities of India", "abstract": "The present work aims to investigate seasonal variations in air pollution levels in Lucknow and assess the ambient air quality of the city together with highlighting the health impacts of major pollutants like PM10, PM2.5, SO2, NO2, Pb, Ni and aerosols from 2010 to 2019. The maximum and minimum values of PM10, PM2.5, SO2, NO2, Pb and Ni were found to be 270.75 and 122.45 g/m3, 124.95 and 95.52 g/m3, 25.60 and 8.05 g/m3, 75.65 and 23.85 g/m3, 0.66 and 0.03 g/m3 and 0.07 and 0.01 ng/m3, respectively. Health impact of particulate matter has also been assessed with AirQ+, and it was estimated that long-term exposure of PM10 was attributed to between 37 and 48% for post-neonatal (age 112 months) mortality rate due to all causes, whereas long-term attributable proportions in mortality due to exposure of PM2.5 were to about 19 to 28% from all causes. Further, an attempt has also been made to evaluate the impact of lockdown amid COVID-19 on the ambient air quality of Lucknow. During the lockdown, PM2.5 levels reduced by 65% (at Gomti Nagar), 23% (at central school), 79% (at Lalbagh) and 35% (at Talkatora), due to which, air quality index of Gomti Nagar came down to 43, well below 50 which falls in the healthy range. NO2 levels also came down. However, levels of SO2 did not show significant reduction. Correlating the data between aerosol optical depth and Angstrom exponent by Pearson correlation analysis revealed a significant positive correlation (r = 0.65, P ", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/BG-2020-419", "year": 2020, "title": "Spatiotemporal patterns of N2 fixation in coastal waters derived from rate measurements and remote sensing", "abstract": "Abstract. Coastal lagoons are important sites for nitrogen (N) removal via sediment burial and denitrification. Blooms of heterocystous cyanobacteria may diminish N retention as dinitrogen (N2) fixation offsets atmospheric losses via denitrification. We measured N2 fixation in the Curonian Lagoon, Europe's largest coastal lagoon, to better understand the factors controlling N2 fixation in the context of seasonal changes in phytoplankton community composition and external N inputs. Temporal patterns in N2 fixation were primarily determined by the abundance of heterocystous cyanobacteria, mainly Aphanizomenon flosaquae, which became abundant after the decline in riverine nitrate inputs associated with snowmelt. Heterocystous cyanobacteria dominated the summer phytoplankton community resulting in strong correlations between chlorophyll-a (Chl-a) and N2 fixation. We used regression models relating N2 fixation to Chl-a, along with remote sensing-based estimates of Chl-a to derive lagoon-scale estimates of N2 fixation. N2 fixation by pelagic cyanobacteria was found to be a significant component of the lagoon's N budget based on comparisons to previously derived fluxes associated with riverine inputs, sediment-water exchange and losses via denitrification. To our knowledge, this is the first study to derive ecosystem-scale estimates of N2 fixation by combining remote sensing of Chl-a with empirical models relating N2 fixation rates to Chl-a.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2020JD032615", "year": 2020, "title": "In Situ Observations of Light-Absorbing Carbonaceous Aerosols at Himalaya: Analysis of the South Asian Sources and Trans-Himalayan Valleys Transport Pathways", "abstract": "The mountain-valleys along the south margin of the Himalaya-Tibetan Plateau (HTP), referred to as trans-Himalayan valleys, are transport pathways of atmospheric pollutants from the South Asia lifting to the HTP based on atmospheric models and satellite detections. However, few field studies can be conducted to confirm the aerosol transport along these valleys due to the harsh environment and limited power supply. Individual particle collection instruments offer the unique advantage of collecting samples and tracing particle sources in remote areas due to their portability and efficiency. In this study, transmission electron microscopy was used to study individual particles collected in two trans-Himalayan valleys. We found that 4970% of thousands of particles were light-absorbing carbonaceous aerosols including soot-bearing and tarball-bearing particles in December of 2017. The dominant sizes of soot-bearing and tarball-bearing particles were 151370 and 198255 nm, respectively. The WRF-Chem model and wind field analyses show that the intense regional air pollution with high mass concentrations of light-absorbing carbonaceous aerosol occurred in the South Asia and southwest wind normally prevailed along the trans-Himalayan valleys in the afternoon of each day during wintertime. Backward trajectory and CALIPSO data further confirm that these light-absorbing carbonaceous aerosols from the South Asia were transported to the southern HTP. These carbonaceous aerosols exhibited significantly internally mixing with secondary sulfates. Here individual particle analysis coupled with the WRF-Chem model, the meteorological observation data, and satellite data confirm the trans-Himalayan valleys as the direct channels for abundant carbonaceous aerosols lifting from the South Asia to the HTP.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS11111168", "year": 2020, "title": "Analysis of the ETNA 2015 Eruption Using WRFChem Model and Satellite Observations", "abstract": "The aim of the present work is to utilize a new functionality within the Weather Research and Forecasting model coupled with Chemistry (WRFChem) that allows simulating emission, transport, and settling of pollutants released during the Etna 2015 volcanic activities. This study constitutes the first systematic application of the WRFChem online-based approach to a specific Etna volcanic eruption, with possible effects involving the whole Mediterranean area. In this context, the attention has been focused on the eruption event, recorded from 37 December 2015, which led to the closure of the nearby Catania International Airport. Quantitative meteorological forecasts, analyses of Etna volcanic ash transport, and estimates of the ash ground deposition have been performed. In order to test the performance of the proposed approach, the model outputs have been compared with data provided by satellite sensors and Doppler radars. As a result, it emerges that, as far as the selected eruption event is concerned, the WRFChem model reasonably reproduces the distribution of SO2 and of volcanic ash. In addition, this modeling system may provide valuable support both to airport management and to local stakeholders including public administrations.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S40808-020-00976-7", "year": 2020, "title": "Black carbon pollution simulations: a RegCM4 model projection and assessment during the boreal winter and summer over West Africa region", "abstract": "The increasing sources of black carbon (BC) emission into the atmosphere have made BC a major air pollutant that could contribute significantly and alter the global atmospheric radiation budget. A perturbed global radiation budget will have profound effect on rainfall cycle and dependent socioeconomic activities. In this paper, RegCM version 4.7, a regional climate model, has been used to simulate back carbon (BC) pollution over West Africa. Pollution-radiation feedback option in the model was activated to determine the effect of radiative properties of BC on climate parameters (rainfall, temperature and wind speed). The study attempted to capture the effect of radiative properties of BC on those climate parameters by activating and de-activating radiation feedback option (RFB) of the model under two RCP2.6 and 8.5. When RFB was turned off, both scenarios showed a decrease in the mean monthly rainfall of up to 2 mm/month in the north and 1.2 mm/month in the south of the West African region. Temperature increased by a factor of 2 K/month in the north and south of the region. For the entire region, the temperature projection in the near future (at the end of twenty-first century) showed an increase of about 3 K/month wind speed and slows down generally in the north and south up to a factor of 0.6 ms1/month under both RCPs. However, when RFB was turned on, rainfall decreases by a factor 0.9 mm/month in the south and 0.8 mm/month in the north under RCP2.6 and 8.5, respectively. In summary, results show that elevated BC concentration in the atmosphere will lead to increase in temperature and decrease in rainfall in the near future relative to historical records and these changes could be exacerbated through BC interactive radiation feedback with the atmospheric variables.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/S41558-020-0881-2", "year": 2020, "title": "Arctic sea-ice loss intensifies aerosol transport to the Tibetan Plateau", "abstract": "The Tibetan Plateau (TP) has recently been polluted by anthropogenic emissions transported from South Asia, but the mechanisms conducive to this aerosol delivery are poorly understood. Here we show that winter loss of Arctic sea ice over the subpolar North Atlantic boosts aerosol transport toward the TP in April, when the aerosol loading is at its climatological maximum and preceding the Indian summer monsoon onset. Low sea ice in February weakens the polar jet, causing decreased Ural snowpack via reduced transport of warm, moist oceanic air into the high-latitude Eurasian interior. This diminished snowpack persists through April, reinforcing the Ural pressure ridge and East Asian trough, segments of a quasi-stationary Rossby wave train extending across Eurasia. These conditions facilitate an enhanced subtropical westerly jet at the southern edge of the TP, invigorating upslope winds that combine with mesoscale updrafts to waft emissions over the Himalayas onto the TP.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/BG-18-1857-2021", "year": 2021, "title": "Spatiotemporal patterns of N2 fixation in coastal waters derived from rate measurements and remote sensing", "abstract": "Abstract. Coastal lagoons are important sites for nitrogen (N) removal via sediment burial and denitrification. Blooms of heterocystous cyanobacteria may diminish N retention as dinitrogen (N2) fixation offsets atmospheric losses via denitrification. We measured N2 fixation in the Curonian Lagoon, Europe's largest coastal lagoon, to better understand the factors controlling N2 fixation in the context of seasonal changes in phytoplankton community composition and external N inputs. Temporal patterns in N2 fixation were primarily determined by the abundance of heterocystous cyanobacteria, mainly Aphanizomenon flos-aquae, which became abundant after the decline in riverine nitrate inputs associated with snowmelt. Heterocystous cyanobacteria dominated the summer phytoplankton community resulting in strong correlations between chlorophyll a (Chl a) and N2 fixation. We used regression models relating N2 fixation to Chl a, along with remote-sensing-based estimates of Chl a to derive lagoon-scale estimates of N2 fixation. N2 fixation by pelagic cyanobacteria was found to be a significant component of the lagoon's N budget based on comparisons to previously derived fluxes associated with riverine inputs, sedimentwater exchange, and losses via denitrification. To our knowledge, this is the first study to derive ecosystem-scale estimates of N2 fixation by combining remote sensing of Chl a with empirical models relating N2 fixation rates to Chl a.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S12517-021-06859-0", "year": 2021, "title": "Spatial and temporal variability in dust storms in the Middle East, 20022018: three case studies in July 2009", "abstract": "The Middle East is one of the most vulnerable regions to climate change and severe droughts. Climate change is associated with an increase of extreme weather frequency events across the globe. Climate change and droughts cause both severity and persistence dust storms in this area. In this study, the spatial and temporal variability of dust storms were characterized in the Middle East using satellite data (NDVI, TRMM, and AOD Aqua MODIS), synoptic station observation in Iran, and a numerical Weather Prediction for one dust event. The investigations of NDVI, precipitation rate, surface temperature, and AOD time series have shown that a significant increase in both surface temperature and AOD characterize this area from 2002 until 2018. While the rate of precipitation significantly declined, NDVI does not show specific trends because of its large variability and human influences. However, the study also showed a sharp decline in precipitation and consequently in vegetation cover in 2008, which caused a significant increase in both AOD and frequency of dust days in 2009. More than 100 dust days in five synoptic weather stations in the study area were observed in 2009. Also, this study shows that the number of dust storms has increased due to changes in governing atmospheric patterns over the area. The results (more than 100 dust days in five synoptic weather stations in the study area were observed for 1 year) showed both the effects of the earth surface respectively vegetation pattern changes (based on NDVI) and the atmospheric reasons (decline in precipitation) are the first time investigated in the study area. A numerical model simulation of three severe dust storms in July 2009 shows that dust emissions cover vast parts of the study area including east parts of Syria, Central Iraq, and northern and southern coasts of the Persian Gulf.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/J.1936-704X.2020.3347.X", "year": 2020, "title": "Integrated Hydrologic and Hydraulic Analysis of Torrential Flood Hazard in Arequipa, Peru", "abstract": "Seated at the foot of the Misti volcano in an area prone to intense seasonal rains and earthquakes, the city of Arequipa is highly vulnerable to natural disasters. During the rainy season, intense storms create large volumes of runoff that rush through the city's ephemeral streams, known locally as torrenteras. Episodic flows in these torrenteras have caused flooding, damage to bridges, homes, and other infrastructure, and caused many deaths. In recent years, while unprecedented rain events have caused extreme disasters, the city's population has continued to expand into these channels by creating informal or illegal settlements. Currently, detailed hazard maps of flood-prone areas surrounding the torrenteras are not available to stakeholders in Arequipa. In this study, hydrologic and hydraulic models were combined to assess flash flood hazards, including inundation, velocity hazards, and slope instability hazards. Hydrologic models were created using satellite precipitation data and terrain-sensitive, gridded climate maps to characterize flow within six torrenteras in Arequipa. These flows were used in conjunction with elevation data and data collected in the field using an online mobile application system to develop a hydraulic model of these flood events. Hydraulic model outputs were used to determine flood hazards related to inundation, velocity affecting human stability, and slope instability in case study areas of the torrenteras. We then discuss how this information can be used by disaster risk management groups, water authorities, planners and municipalities, and community groups.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.ENVPOL.2021.116735", "year": 2021, "title": "Brown carbon light absorption over an urban environment in northern peninsular Southeast Asia", "abstract": "Light-absorbing organic carbon (or brown carbon, BrC) has been recognized as a critical driver in regional-to-global climate change on account of its significant contribution to light absorption. BrC sources vary from primary combustion processes (burning of biomass, biofuel, and fossil fuel) to secondary formation in the atmosphere. This paper investigated the light-absorbing properties of BrC such as site-specific mass absorption cross-section (MACBrC), absorption Angstrom exponent (AAEBrC), and the absorbing component of the refractive index (kBrC) by using light absorption measurements from a 7-wavelength aethalometer over an urban environment of Chiang Mai, Thailand in northern peninsular Southeast Asia (PSEA), from March to April 2016. The contribution of BrC to total aerosol absorption (mean SD) was 46 9%, 29 7%, 24 6%, 20 4%, and 15 3% at 370, 470, 520, 590, and 660 nm, respectively, highlighting the significant influence of BrC absorption on the radiative imbalance over northern PSEA. Strong and significant associations between BrC light absorption and biomass-burning (BB) organic tracers highlighted the influence of primary BB emissions. The median MACBrC and kBrC values at 370 nm were 2.4 m2 g1 and 0.12, respectively. The fractional contribution of solar radiation absorbed by BrC relative to BC (mean SD) in the 370950 nm range was estimated to be 34 7%, which can significantly influence the regional radiation budget and consequently atmospheric photochemistry. This study provides valuable information to understand BrC absorption over northern PSEA and can be used in model simulations to reassess the regional climatic impact with greater accuracy.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.117926", "year": 2021, "title": "Spatial-temporal variation characteristics of air pollution and apportionment of contributions by different sources in Shanxi province of China", "abstract": "With the implementation of the Air Pollution Prevention and Control Action Plan (APPCAP) since 2013, significant declines in pollutants concentrations have achieved in nationwide of China. However, as one of the major coal-production bases and intensive energy-consuming provinces in China, Shanxi has still been suffering from severe air quality problems in recent years. In this study, by combining a detailed bottom-up emission inventory and the weather research and forecasting (WRF) model/comprehensive air quality model with extensions (CAMx) model, the evolution of pollutant concentrations, source apportionment, and migration potentials from 2012 to 2015 in Shanxi are investigated. Estimated primary air pollutants emission declined significantly during 20122015. Compared with 2012, the simulated concentrations of PM2.5, PM10, SO2 and NO2 in January of 2015 are reduced by 24.7%, 24.1%, 23.0% and 18.0%, respectively. In contrast, heavy contaminated areas have shown negligible variations, which are highly concentrated in Taiyuan, Linfen, Jincheng, Changzhi, Lvliang, Yangquan and Jinzhong cities. In terms of contribution by source categories, the other industries and residential sources are identified as the most significant local contributors for PM2.5 and PM10, while SO2 and NO2 are mainly emitted by other industries and power plants. Scenarios analysis of 50% emission mitigation suggests that the emission reduction measures are generally more effective in summer than in winter. Moreover, the mitigation potential for each city varies from each other. These results indicate that more appropriate seasonal-specific emission reduction measures in each prefecture-level city should be implemented to further improve regional air quality and thus better protect public health.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-9-9001-2009", "year": 2009, "title": "Evaluation of black carbon estimations in global aerosol models", "abstract": "Abstract. We evaluate black carbon (BC) model predictions from the AeroCom model intercomparison project by considering the diversity among year 2000 model simulations and comparing model predictions with available measurements. These model-measurement intercomparisons include BC surface and aircraft concentrations, aerosol absorption optical depth (AAOD) retrievals from AERONET and Ozone Monitoring Instrument (OMI) and BC column estimations based on AERONET. In regions other than Asia, most models are biased high compared to surface concentration measurements. However compared with (column) AAOD or BC burden retreivals, the models are generally biased low. The average ratio of model to retrieved AAOD is less than 0.7 in South American and 0.6 in African biomass burning regions; both of these regions lack surface concentration measurements. In Asia the average model to observed ratio is 0.7 for AAOD and 0.5 for BC surface concentrations. Compared with aircraft measurements over the Americas at latitudes between 0 and 50N, the average model is a factor of 8 larger than observed, and most models exceed the measured BC standard deviation in the mid to upper troposphere. At higher latitudes the average model to aircraft BC ratio is 0.4 and models underestimate the observed BC loading in the lower and middle troposphere associated with springtime Arctic haze. Low model bias for AAOD but overestimation of surface and upper atmospheric BC concentrations at lower latitudes suggests that most models are underestimating BC absorption and should improve estimates for refractive index, particle size, and optical effects of BC coating. Retrieval uncertainties and/or differences with model diagnostic treatment may also contribute to the model-measurement disparity. Largest AeroCom model diversity occurred in northern Eurasia and the remote Arctic, regions influenced by anthropogenic sources. Changing emissions, aging, removal, or optical properties within a single model generated a smaller change in model predictions than the range represented by the full set of AeroCom models. Upper tropospheric concentrations of BC mass from the aircraft measurements are suggested to provide a unique new benchmark to test scavenging and vertical dispersion of BC in global models.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S11356-017-0715-6", "year": 2018, "title": "Spatiotemporal characteristics of aerosols and their trends over mainland China with the recent Collection 6 MODIS and OMI satellite datasets", "abstract": "With the rapid development of Chinas economy and high rate of industrialization, environmental pollution has become a major challenge for the country. The present study is aimed at analyzing spatiotemporal heterogeneities and changes in trends of different aerosol optical properties observed over China. To achieve this, Collection 6 Level 3 data retrieved from the Moderate Resolution Imaging Spectroradiometer (MODIS; 20022016) and Ozone Monitoring Instrument (OMI; 20052016) sensors were used to investigate aerosol optical depth (AOD550), Angstrm exponent (AE470660), and Absorption Aerosol Index (AAI). The spatial distribution of annual mean AOD550 was noticed to be high over economically and industrialized regions of the east, south, and northeast of China, while low aerosol loadings were located over rural and less-developed areas of the west and northeast of China. High AE470660 (> 1.0) values were characterized by the abundance of fine-mode particles and vice versa, likely attributed to large anthropogenic activities. Similarly, high AOD with corresponding high AE and low AAI was characterized over the urban-industrialized regions of the central, east, and south of China during most of the months, being more pronounced in June and July. On seasonal scale, AOD values were found to be high during spring, followed by the summer and autumn, and low during the winter season. It is also evident that all aerosol parameters showed a single-peak frequency distribution in all seasons over entire China. Further, the annual, monthly, and seasonal spatial trends revealed a decreasing trend in AOD over most regions of China, except in the southwest of China, which showed a positive increasing trend. Significant increasing trends were noted in AAI for all the seasons, particularly during autumn and winter, resulting in a large amount of the absorbing type of aerosols produced from biomass burning and desert dust.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.SCITOTENV.2016.11.025", "year": 2017, "title": "A review of biomass burning: Emissions and impacts on air quality, health and climate in China", "abstract": "Biomass burning (BB) is a significant air pollution source, with global, regional and local impacts on air quality, public health and climate. Worldwide an extensive range of studies has been conducted on almost all the aspects of BB, including its specific types, on quantification of emissions and on assessing its various impacts. China is one of the countries where the significance of BB has been recognized, and a lot of research efforts devoted to investigate it, however, so far no systematic reviews were conducted to synthesize the information which has been emerging. Therefore the aim of this work was to comprehensively review most of the studies published on this topic in China, including literature concerning field measurements, laboratory studies and the impacts of BB indoors and outdoors in China. In addition, this review provides insights into the role of wildfire and anthropogenic BB on air quality and health globally. Further, we attempted to provide a basis for formulation of policies and regulations by policy makers in China.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1175/JAMC-D-16-0354.1", "year": 2017, "title": "Statistics and Meteorology of Air Pollution Episodes over the South African Highveld Based on SatelliteModel Datasets", "abstract": "The meteorological conditions associated with air pollution episodes on South Africas Highveld were studied using Ozone Monitoring Instrument (OMI) and Atmospheric Infrared Sounder (AIRS) satellite estimates, MERRA2 reanalysis model products, and in situ weather data. Surface-layer sulfur dioxide (SO\n 2\n ) and nitrogen dioxide (NO\n 2\n ) display high concentrations during winter (MayJuly) and provide a focus for statistical analysis of monthly and daily time series. Highveld area-averaged monthly model SO\n 2\n was temporally correlated with boundary layer height (correlation coefficient of 0.76) and temperature lapse rate (+0.65) for the period of 19802015, but relationships with winds were weak. Daily Highveld area-averaged satellite NO\n 2\n was related to dewpoint temperature (0.59) and exhibited pulsing in the range of 724 days for 200515. High concentrations of these short-lived locally generated air pollutants were found over and southeast of Johannesburg as a result of urban and industrial emissions. The spatial regression of daily NO\n 2\n onto regional sea level air pressure fields for MayJuly over 200515 revealed the slow eastward movement of an anticyclone. At the climatic time scale, Pacific Ocean La Nina conditions favored an increase of MayJuly SO\n 2\n concentrations when sea surface temperatures in the equatorial Atlantic Ocean were warmer than normal. The meteorological pattern underlying the highest-ranked air pollution event of 1825 July 2008 was characterized by sharp anticyclonic curvature of low-level winds that induce subsidence and consequently a stable lapse rate and low dewpoint temperature (5C). The wind vorticity exerted a stronger influence on dispersion than did the surface divergence. This new understanding will underpin better air-quality forecasts over the South African Highveld.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-18-2035-2018", "year": 2018, "title": "Predicting decadal trends in cloud droplet number concentration using reanalysis and satellite data", "abstract": "Abstract. Cloud droplet number concentration (CDNC) is the key state variable that moderates the relationship between aerosol and the radiative forcing arising from aerosolcloud interactions. Uncertainty related to the effect of anthropogenic aerosol on cloud properties represents the largest uncertainty in total anthropogenic radiative forcing. Here we show that regionally averaged time series of the Moderate-Resolution Imaging Spectroradiometer (MODIS) observed CDNC of low, liquid-topped clouds is well predicted by the MERRA2 reanalysis near-surface sulfate mass concentration over decadal timescales. A multiple linear regression between MERRA2 reanalyses masses of sulfate (SO4), black carbon (BC), organic carbon (OC), sea salt (SS), and dust (DU) shows that CDNC across many different regimes can be reproduced by a simple power-law fit to near-surface SO4, with smaller contributions from BC, OC, SS, and DU. This confirms previous work using a less sophisticated retrieval of CDNC on monthly timescales. The analysis is supported by an examination of remotely sensed sulfur dioxide (SO2) over maritime volcanoes and the east coasts of North America and Asia, revealing that maritime CDNC responds to changes in SO2 as observed by the ozone monitoring instrument (OMI). This investigation of aerosol reanalysis and top-down remote-sensing observations reveals that emission controls in Asia and North America have decreased CDNC in their maritime outflow on a decadal timescale.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-18-11831-2018", "year": 2018, "title": "Extreme levels of Canadian wildfire smoke in the stratosphere over central Europe on 2122 August 2017", "abstract": "Abstract. Light extinction coefficients of 500 Mm1, about 20 times higher than after the Pinatubo volcanic eruptions in 1991, were observed by European Aerosol Research Lidar Network (EARLINET) lidars in the stratosphere over central Europe on 2122 August 2017. Pronounced smoke layers with a 12 km vertical extent were found 25 km above the local tropopause. Optically dense layers of Canadian wildfire smoke reached central Europe 10 days after their injection into the upper troposphere and lower stratosphere which was caused by rather strong pyrocumulonimbus activity over western Canada. The smoke-related aerosol optical thickness (AOT) identified by lidar was close to 1.0 at 532 nm over Leipzig during the noon hours on 22 August 2017. Smoke particles were found throughout the free troposphere (AOT of 0.3) and in the pronounced 2 km thick stratospheric smoke layer at an altitude of 1416 km (AOT of 0.6). The lidar observations indicated peak mass concentrations of 70100 g m3 in the stratosphere. In addition to the lidar profiles, we analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power (FRP) over Canada, and the distribution of MODIS AOT and Ozone Monitoring Instrument (OMI) aerosol index across the North Atlantic. These instruments showed a similar pattern and a clear link between the western Canadian fires and the aerosol load over Europe. In this paper, we also present Aerosol Robotic Network (AERONET) sun photometer observations, compare photometer and lidar-derived AOT, and discuss an obvious bias (the smoke AOT is too low) in the photometer observations. Finally, we compare the strength of this record-breaking smoke event (in terms of the particle extinction coefficient and AOT) with major and moderate volcanic events observed over the northern midlatitudes.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/IJERPH15112472", "year": 2018, "title": "Elevated black carbon concentrations and atmospheric pollution around Singrauli coal-fired thermal power plants (India) using ground and satellite data", "abstract": "The tropospheric NO2 concentration from OMI AURA always shows high concentrations of NO2 at a few locations in India, one of the high concentrations of NO2 hotspots is associated with the locations of seven coal-fired Thermal Power plants (TPPs) in Singrauli. Emissions from TPPs are among the major sources of black carbon (BC) soot in the atmosphere. Knowledge of BC emissions from TPPs is important in characterizing regional carbonaceous particulate emissions, understanding the fog/haze/smog formation, evaluating regional climate forcing, modeling aerosol optical parameters and concentrations of black carbon, and evaluating human health. Furthermore, elevated BC concentrations, over the Indo-Gangetic Plain (IGP) and the Himalayan foothills, have emerged as an important subject to estimate the effects of deposition and atmospheric warming of BC on the accelerated melting of snow and glaciers in the Himalaya. For the first time, this study reports BC concentrations and aerosol optical parameters near dense coal-fired power plants and open cast coal mining adjacent to the east IGP. In-situ measurements were carried out in Singrauli (located in south-east IGP) at a fixed site about 10 km from power plants and in transit measurements in close proximity to the plants, for few days in the month of January and March 2013. At the fixed site, BC concentration up to the 95 gm3 is observed with strong diurnal variations. BC concentration shows two maxima peaks during early morning and evening hours. High BC concentrations are observed in close proximity to the coal-fired TPPs (>200 gm3), compared to the outside domain of our study region. Co-located ground-based sunphotometer measurements of aerosol optical depth (AOD) show strong spatial variability at the fixed site, with AOD in the range 0.380.58, and the highest AOD in the range 0.70.95 near the TPPs in transit measurements (similar to the peak of BC concentrations). Additionally, the Angstrom exponent was found to be in the range 0.41.0 (maximum in the morning time) and highest in the proximity of TPPs (~1.0), suggesting abundance of fine particulates, whereas there was low Angstrom exponent over the surrounding coal mining areas. Low Angstrom exponent is characterized by dust from the unpaved roads and nearby coal mining areas. MODIS derived daily AOD shows a good match with the MICROTOPS AOD. The CALIPSO derived subtypes of the aerosol plot shows that the aerosols over Singrauli region are mainly dust, polluted dust, and elevated smoke. The preliminary study for few days provides information about the BC concentrations and aerosol optical properties from Singrauli (one of the NO2 hotspot locations in India). This preliminary study suggests that long-term continuous monitoring of BC is needed to understand the BC concentrations and aerosol optical properties for better quantification and the estimation of the emission to evaluate radiative forcing in the region.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.33411/IJIST/2019010101", "year": 2019, "title": "Appraisal of Urban Heat Island over Gujranwala and its environmental impact assessment using satellite imagery (1995-2016)", "abstract": "Rapid urbanization and concretization are the main sources of formation and existence of Urban Heat Island (UHI). Due to high concentration of pollutants in urban environments, the residents are exposed to unexpected health issues. This study aims at delineating the temporal variations in the spatial extent of UHI over Gujranwala using Landsat thermal imagery. It also aims at determining the variations in pollutant concentration in the atmosphere due to vehicles tailpipe emissions and fossil fuel burning by industrial plants. We used various indices e.g., NDVI, NDBI, NDWI and land surface temperature calculations to investigate spatiotemporal variations in urban growth patterns and their impacts on the UHI. The results show that the UHI enlarged in all direction specially in the north west during the study period which is similar to urban growth trends. There also exist positive correlation between industrial and vehicles discharge with pollutants concentration in atmosphere. Remote sensing tools proved elegant in trend mapping and analysis.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1002/2017JD027750", "year": 2018, "title": "Anomalous lightning behavior during the 26-27 August 2007 Northern Great Plains severe weather event", "abstract": "Positive polarity lightning strokes can be useful indicators of thunderstorm behavior. A combination of National Lightning Detection Network and Next Generation Radar retrievals is used to analyze the anomalous positive cloud-to-ground (CG) lightning behavior of a rare, late summer severe weather event that occurred on 2627 August 2007 in the Northern Great Plains region of the United States and southern Canada. Seven discrete supercells (SC1SC7) exhibiting frequent and intense lightning were responsible for numerous reports of severe weather (e.g., severe hail and 16 tornadoes) including catastrophic damage to the town of Northwood, North Dakota, caused by SC2. Biomass burning smoke from wildfires in Idaho and Montana was present prior to convective initiation. A positive CG lightning stroke rate of nearly 30 strokes per minute was observed 10 min before the EF4 tornado struck Northwood. SC2 was also responsible for all the reports of tornadoes exceeding an EF2 rating. The strongest peak currents (>200 kA) were observed in SC1SC4 with SC2 having a maximum value of 280 kA. SC2 dominated the statistics of the line of supercells accounting for 27% of all CG lightning strokes. Positive CG lightning accounted for over 40% of all CG lightning strokes in SC4SC7 on average, and the maximum exceeded 90% in SC6 and SC7. Increasing positive CG lightning dominance was correlated with an increasing northward gradient of smoke aerosol loading in addition to severe weather being reported before the maximum in positive CG lighting stroke rate (SC5 and SC6). This suggests that a complex combination of synoptic forcing and aerosol perturbation likely led to the observed anomalous positive CG lightning behavior in the supercells.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.33889/IJMEMS.2019.4.2-023", "year": 2019, "title": "Analysis of local climate variations using correlation between satellite measurements of methane emission and temperature trends within physiographic regions of Ukraine", "abstract": "Paper aimed to the description of the methods of analysis and measurements of atmospheric greenhouse gases (GHG),\nespecially, methane concentration using satellite tools for climate change model improvement. The experimental\naccuracy estimation of narrow-band spectral indices restoration by the wide-band multispectral image is performed.\nThree methods for narrow-band spectral indices restoration are analyzed. The method on the basis of spectra translation\nis recommended for practical application.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/MET.1878", "year": 2020, "title": "Air quality in the Galapagos Islands: a baseline view from remote sensing and in situ measurements", "abstract": "A characterization of ambient air levels of PM2.5, O3, SO2, NO2 and CO in the Galapagos Islands of Ecuador is presented from in situ and remote sensing observations. PM2.5 was derived from aerosol optical depth (AOD; AERONET) measured at the Universidad San Francisco de Quito, Galapagos Campus (20172019). Boundary layer (BL) ozone was obtained from Southern Hemisphere Additional Ozonesondes (SHADOZ) profiles (19982016). Background SO2 and pollution events during volcanic eruptions (20052018) were estimated from Ozone Monitoring Instrument (OMI) total column measurements through a well-mixed volume approach. Similarly, ambient NO2 was estimated from OMI data (20122019). CO was obtained from Measurement Of Pollution In The Troposphere (MOPITT) observations (20122017). The study was complemented using Modern-Era Retrospective Analysis for Research and Applications (MERRA-2) reanalysis products and backward trajectory model runs. From the results, baseline levels of the analysed species (PM2.5 = 3.8 gm3, O3 = 17 ppbv, SO2 = 3.6 ppbv, CO = 80 ppbv, NO2 in populated islands = 23 pptv as one year averages) are comparable with other pristine regions, but some factors can cause increased concentrations. First, high tourism seasons (FebruaryApril and JulySeptember) raise background PM2.5, NO2 and CO. Furthermore, signals in JulySeptember can be augmented by transport from biomass-burning regions in the Amazon. This latter factor episodically causes ozone to increase up to 4575 ppbv (1 hr mean). Lastly, volcanic eruptions raise SO2 up to almost 700 ppbv (24 hr mean) and increase PM2.5 to 29.5 gm3 (1 hr mean). The present study provides for the first time baseline levels of air contaminants in the Galapagos, and identifies specific sources whose effect in time is necessary to monitor given global conditions of vulnerable environmental quality.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1109/JSTARS.2018.2832131", "year": 2018, "title": "Estimation of power plant emissions with unscented Kalman Filter", "abstract": "Emissions from power plants constitute a major part of air pollution and should be adequately estimated. In this paper, we consider the problem of estimating nitrogen dioxide (NOX) emission of power plants by developing an inverse method to integrate satellite observations of atmospheric pollutant column concentrations with species concentrations and direct sensitivities predicted by a regional air quality model, in order to discern biases in the emissions of the pollutant precursors. Using this method, the emission fields are analyzed using a bottom-up approach, with an inversion performed by an unscented Kalman filter (UKF) to improve estimation profiles from emissions inventories data for the Sydney metropolitan area. The idea is to integrate information from the original inventories with tropospheric nitrogen dioxide (NO2) emissions estimated during one month from the air pollution model-chemical transport model, and then, for validation, to compare the resulting model with satellite retrievals from the ozone monitoring instrument (OMI) above the region. The UKF-based estimation of NO2 emissions shows better agreement with OMI observations, implying a significant improvement in accuracy as compared with the original inventories. Therefore, the proposed method is a promising tool for estimation of air emissions in urban areas.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2019JD030639", "year": 2019, "title": "Spatial and temporal analysis of precipitation extremities of Eastern Nepal in the last two decades (19972016)", "abstract": "In recent days there have been discussions regarding the impact of climate change and its vagaries of the weather, particularly concerning extreme events. Nepal, being a mountainous country, is more susceptible to precipitation extreme events and related hazards, which hinder the socioeconomic development of the nation. In this regard, this study aimed to address this phenomenon for one of the most naturally and socioeconomically important regions of Nepal, namely, Eastern Nepal. The data were collected for the period of 1997 to 2016. The interdecadal comparison for two periods (19972006 and 20072016) was maintained for the calculation of extreme precipitation indices as per recommended by Expert Team on Climate Change Detection and Indices. Linear trends were calculated by using Mann-Kendall and Sen's Slope estimator. The average annual precipitation was found to be decreasing at an alarming rate of 20 mm/year in the last two decades' tenure. In case of extreme precipitation events, consecutive dry days, one of the frequency indices, showed a solo increase in its trend (mostly significant). Meanwhile, all the intensity indices of extreme precipitation showed decreasing trends (mostly insignificant). Thus, it can be concluded that Eastern Nepal has witnessed some significant drier days in the last two decades, as the events of heavy, very heavy, extremely heavy precipitation events, and annual wet day precipitation (PRCPTOT) were found to be decreasing. The same phenomena were also seen in the Tropical Rainfall Measuring Mission 3B42 V7 satellite precipitation product for whole Nepal.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/JMSE7030075", "year": 2019, "title": "Medicanes triggering chlorophyll increase", "abstract": "Studies have shown that hurricanes and typhoons, apart from being extreme weather phenomena, cause increases in marine chlorophyll-a concentrations and even phytoplankton blooms. Medicanes are the tropical-like Mediterranean cyclones that induce hazardous weather conditions as well. In this study, a couple of medicanes, over the central and eastern parts of the Sea, are examined for the first time in respect to their possible influence on chlorophyll concentrations. The affected area was delineated with the use of numerical model data, while the sea surface temperature and chlorophyll variations were assessed based on satellite-derived data. The results showed that medicanes trigger surface chlorophyll increases; after the cyclones passage, the concentrations were higher compared both with those before and with the climatological monthly values over a large part of the affected area. The mechanisms proposed to explain hurricanes favorable influence on chlorophyll concentration seem to be valid for medicanes as well. Area averaged chlorophyll concentrations presented analogous increases to the ones reported for hurricanes, though on a smaller scale. Despite the much lower intensity of medicanes compared with hurricanes, the observed increase in surface chlorophyll after their passage points to their favorable influence.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2018JD029461", "year": 2019, "title": "A 10-year record of aerosol optical properties and radiative forcing over three environmentally distinct AERONET sites in Kenya, East Africa", "abstract": "In the framework of Aerosol Robotic Network (AERONET), the aerosol optical, microphysical, and radiative properties were investigated over three sites (CRPSM_Malindi, Nairobi, and ICIPE_Mbita) in Kenya, East Africa, during 20062015. The annual mean () aerosol optical depth at 440 nm (AOD440) was found high at Mbita (0.27 0.09) followed by Malindi (0.26 0.07), and low at Nairobi (0.19 0.04). Whereas the seasonal mean AOD440 noticed high (low) values during the local dry (wet) seasons. The aerosol optical properties: AOD, single scattering albedo, asymmetry parameter, and complex aerosol refractive index exhibited significant temporal and spectral heterogeneities illustrating the complexity of aerosol types with an abundance of fine-mode aerosols during the local dry (JuneJulyAugust) season. Characterization of major aerosol types revealed the dominance of mixed-type followed by biomass burning aerosols. The aerosol volume size distribution revealed that the coarse- over fine-mode aerosols showed a significant contribution to the total volume particle concentration, especially at high (>0.3) AOD440. Further, the aerosol columnar number size distribution retrieved from the King's inversion of spectral AOD exhibited a power law distribution affirming multiplicity of aerosol sources. The direct aerosol radiative forcing values simulated in the shortwave region using the Santa Barbara DISORT Atmospheric Radiative Transfer model showed good correlation (r = >0.85) with the AERONET-derived ones at the top-of-atmosphere, bottom-of-atmosphere, and within the atmosphere. The annual mean () top-of-atmosphere, bottom-of-atmosphere, and within the atmosphere forcing values were found in the range from 8.10 3.75 to 13.23 4.87, 34.54 4.86 to 46.11 10.27, and 26.63 6.43 to 36.24 7.26 W/m2, respectively, with an atmospheric heating rate of 0.74 0.121.02 0.20 K/day. The Santa Barbara DISORT Atmospheric Radiative Transfer-derived direct aerosol radiative forcing exhibited significant temporal heterogeneity with high (low) during the local dry (wet) seasons. Results derived from the present study forms a basis for regional climate change studies and could increase the accuracy of climate models over this unexplored region of Africa.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1051/E3SCONF/202014903007", "year": 2020, "title": "Variations of atmospheric aerosol parameters in periods of seismic activity in Tien-Shan", "abstract": "Combination of numerical modeling (MERRA) and ground-\nbased (AERONET) monitoring of atmospheric aerosol parameters were\nused to discover a possible connection to seismic activities within the\nterritory of Tien-Shan. The obtained results demonstrated consistent\nbehavior between increase of aerosol optical thickness (AOT) and powerful\nearthquakes, epicenters of which were located within 200 km from the\n\"Issyk-Kul\" station (AERONET). Thereat, the dominant role was played by\nfine-dispersed particles, which virtually determined the nature of \nevolution. We also observed well-defined changes of the ratio between mass\nfraction PM 1.0 (particles less than 1.0 m aerodynamic diameter) and optical\nthickness of aerosol scattering several days before an earthquake of M > 5.0\nmagnitude.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.30758/0555-2648-2020-66-1-66-81", "year": 2020, "title": "Variations of methane in the Antarctic atmosphere in 2009-2017 by ground-based and satellite data", "abstract": "The article presents the results of systematic measurements (20092017) of the total column abundances of methane (TC_CH4 ) and the column-averaged concentration (X_CH 4 ) at the Antarctic station Novolazarevskaya. Solar radiation is recorded in the range 2990 3006 cm 1 using a diffraction spectrometer with 0.2 cm 1 resolution. The inverse task CH 4 total column determining is achieved using the SFIT4 v0.9.4.4 code. The analysis shows that during the measurement period the average TC_CH4 was (3.40.8).10 19 molecules/cm 2 during the measurement period, and the average X_CH 4 is (166334) ppbv. TC_CH 4 trend is (4.52.2).10 15 molecules/cm 2 /month, and X_CH4 trend is (0.28 0.11) ppbv/month. The average TC_CH 4 values and trend at Novolazarevskaya are in good agreement with the measurements by the Brucker120HR instrument at the Arrival Heights station. Seasonal variations of atmospheric methane have the maximum in OctoberNovember and the minimum in MayJuly. The trends of surface methane concentrations at Sywa, the Halley station and the Amundsen-Scott South Pole station are 0.59 0.61 ppbv/month and exceed the trend of the column-averaged concentration at Novolazarevskaya and AIRS trends for the troposphere (0.24 0.32) ppbv/month, due to a decrease in the maximal values of TC_CH4 in the period after 2014. The closest agreement of X_CH 4 variations at Novolazarevskaya with AIRS data is observed at the levels of 150200 hPa. Significant semiannual harmonics varied with height are characteristic of CH4 variations according to the AIRS data. The interference of annual and semiannual harmonics leads to the appearance of two maxima in the seasonal variations of methane with relative position to each other varies with height. The statistical model is developed for all the series considered. It approximates the trend, annual and semi-annual components of CH4 oscillations.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.3389/FEART.2019.00092", "year": 2019, "title": "Seasonal Shift of the Diurnal Cycle of Rainfall Over Medellin's Valley, Central Andes of Colombia (1998-2005)", "abstract": "The spatiotemporal variability of precipitation in regions of complex mountainous terrains constitutes one of the most challenging research topics of geosciences. This paper explores hourly precipitation data from a set of 25 stations spanning the period 1998 to 2005 within northwestern Colombia, in the Aburra Valley and the neighboring San Nicolas plateau (75.16W-6N and 75.66W-6.6N) which accounts for a land area of approximately 4000 km2. Our aim is to identify the main features of the diurnal cycle of precipitation over this complex terrain. We found that the average diurnal cycle of rainfall in the study region is bimodal at regional scale although it results from the superposition of two unimodal diurnal cycles shifting its phase throughout the seasons of the year. From October to April, average diurnal rainfall peaks in the afternoon hours (13:00-16:00 LST) but from May to September, the phase of the diurnal cycle changes to midnight hours (22:00-02:00 LST). Three low-level jets (LLJs), namely Caribbean, CHOCO, and the so-called Corriente de los Andes Orientales (CAO), are relevant to explain the seasonal shift of the diurnal cycle given their modulation of the seasonal variation of moisture sources and transport over this region. During June-July-August, moisture from afternoon evaporation processes at the bottom of the inter-Andean Magdalena Valley, located at the east of the study region, is transported by anabatic and easterly trade winds and contribute to explain the midnight and early morning peak. The life cycle of convective processes influences the orographic nature of rainfall distribution and timing in the region since deep convective cores are related with the afternoon peak, whereas wide convective cores with the early morning peak.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1126/SCIENCE.AAX4767", "year": 2019, "title": "Kilauea lava fuels phytoplankton bloom in the North Pacific Ocean", "abstract": "Ocean greening off Hawai'i\nFrom June to August 2018, the eruption of Kilauea volcano triggered a diatom-dominated phytoplankton bloom. Wilson et al. set sail to sample the plume, deploying subsea gliders and using satellite monitoring to measure the dynamics of this rare event in the nutrient-poor Pacific (see the Perspective by Ducklow and Plank). They found subsurface chlorophyll maxima not visible by remote sensing, performed transcriptome and N isotope marker analysis, and measured nutrients, partitioning of biomass into different organisms, and primary production. Much of the data are corroborated by physical modeling of the ocean dynamics. The authors conclude that the plume was fed by the lava heating subsurface water and triggering upwelling of deepwater nutrients to the surface rather than by direct injection of micronutrients from lava.\nScience, this issue p. 1040; see also p. 978\nFrom June to August 2018, the eruption of Kilauea volcano on the island of Hawaii injected millions of cubic meters of molten lava into the nutrient-poor waters of the North Pacific Subtropical Gyre. The lava-impacted seawater was characterized by high concentrations of metals and nutrients that stimulated phytoplankton growth, resulting in an extensive plume of chlorophyll a that was detectable by satellite. Chemical and molecular evidence revealed that this biological response hinged on unexpectedly high concentrations of nitrate, despite the negligible quantities of nitrogen in basaltic lava. We hypothesize that the high nitrate was caused by buoyant plumes of nutrient-rich deep waters created by the substantial input of lava into the ocean. This large-scale ocean fertilization was therefore a unique perturbation event that revealed how marine ecosystems respond to exogenous inputs of nutrients.\nVolcanic eruptioninduced upwelling generated a phytoplankton bloom in nutrient-poor oceanic waters.\nVolcanic eruptioninduced upwelling generated a phytoplankton bloom in nutrient-poor oceanic waters.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1134/S1028334X17070261", "year": 2017, "title": "Anomalous transboundary transport of the products of biomass burning from North American wildfires to Northern Eurasia", "abstract": "An analysis of smoke in the atmosphere over the Russian Far East and Eastern Siberia in August 2004 was carried out. The results of the analysis indicate that the cause of the smoke in the atmosphere over these regions (with the values of aerosol optical depth exceeding 4 over the north of Kamchatka Krai) was the long-range transboundary transport of combustion products from North American wildfires. The anomalous (westward) long-range transport of the products of biomass burning was caused by atmospheric circulation characteristic for the atmospheric blocking of the dipole-type with a high-pressure region over the Chukchi Sea and a low pressure region over the south of the Bering Sea.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1177/0734242X19882482", "year": 2019, "title": "Investigation and modelling of greenhouse gas emissions resulting from waste collection and transport activities:", "abstract": "Greenhouse gas emissions resulting from municipal solid waste management activities and the associated climate change impacts are getting great attention worldw...", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/HESS-15-1713-2011", "year": 2011, "title": "Hydrological differentiation and spatial distribution of high altitude wetlands in a semi-arid Andean region derived from satellite data", "abstract": "Abstract. High Altitude Wetlands of the Andes (HAWA) belong to a unique type of wetland within the semi-arid high Andean region. Knowledge about HAWA has been derived mainly from studies at single sites within different parts of the Andes at only small time scales. On the one hand, HAWA depend on water provided by glacier streams, snow melt or precipitation. On the other hand, they are suspected to influence hydrology through water retention and vegetation growth altering stream flow velocity. We derived HAWA land cover from satellite data at regional scale and analysed changes in connection with precipitation over the last decade. Perennial and temporal HAWA subtypes can be distinguished by seasonal changes of photosynthetically active vegetation (PAV) indicating the perennial or temporal availability of water during the year. HAWA have been delineated within a region of 12 800 km2 situated in the Northwest of Lake Titicaca. The multi-temporal classification method used Normalized Differenced Vegetation Index (NDVI) and Normalized Differenced Infrared Index (NDII) data derived from two Landsat ETM+ scenes at the end of austral winter (September 2000) and at the end of austral summer (May 2001). The mapping result indicates an unexpected high abundance of HAWA covering about 800 km2 of the study region (6 %). Annual HAWA mapping was computed using NDVI 16-day composites of Moderate Resolution Imaging Spectroradiometer (MODIS). Analyses on the relation between HAWA and precipitation was based on monthly precipitation data of the Tropical Rain Measurement Mission (TRMM 3B43) and MODIS Eight Day Maximum Snow Extent data (MOD10A2) from 2000 to 2010. We found HAWA subtype specific dependencies on precipitation conditions. A strong relation exists between perennial HAWA and snow fall (r2: 0.82) in dry austral winter months (June to August) and between temporal HAWA and precipitation (r2: 0.75) during austral summer (March to May). Annual changes in spatial extend of perennial HAWA indicate alterations in annual water supply generated from snow melt.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.4209/AAQR.2015.05.0346", "year": 2016, "title": "Transported Mineral Dust Deposition Case Study at a Hydrologically Sensitive Mountain Site: Size and Composition Shifts in Ambient Aerosol and Snowpack", "abstract": "ABSTRACTTransported mineral dust deposition to remote mountain snow decreases snow albedo and increases absorption of solar radiation, which accelerates snowpack melt and alters water supply. Mineralogy and chemical composition determine dust particle optical properties, which vary by source region. While impacts of dust deposition at remote mountain sites have been established, few studies have connected the chemical composition of ambient particles during deposition events with the properties of those deposited on the snowpack. Ambient particles and surface snow were sampled in the San Juan Mountains of southwestern Colorado, which frequently experiences dust deposition in the spring and has evidence of dust-enhanced snow melt. Individual particles were analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX). The number concentration and size distribution of insoluble residues in the top level of snow were determined with nanoparticle tracking analysis (NTA). During a minor dust event (April 23, 2015), the fraction of absorbing iron-enriched dust in the ambient aerosol, the number concentration, and size of insoluble residues in snow all increased. This can be traced to shifts in mineral dust source region within the Colorado Plateau, during which, there were higher wind speeds leading to increased transport. The shift in chemical composition and mineralogy of the transported dust has the potential to impact snowpack radiative forcing during dry deposition. In addition, it can also modify the snowpack through scavenging of particles during wet deposition, as well as alter the properties of clouds and orographic precipitation. Understanding these impacts is crucial to understanding the hydrological cycle at remote mountain sites.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/S13143-015-0084-3", "year": 2016, "title": "Satellite and ground-based remote sensing of aerosols during intense haze event of October 2013 over lahore, Pakistan", "abstract": "Due to increase in population and economic development, the mega-cities are facing increased haze events which are causing important effects on the regional environment and climate. In order to understand these effects, we require an in-depth knowledge of optical and physical properties of aerosols in intense haze conditions. In this paper an effort has been made to analyze the microphysical and optical properties of aerosols during intense haze event over mega-city of Lahore by using remote sensing data obtained from satellites (Terra/Aqua Moderate-resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO)) and ground based instrument (AErosol RObotic NETwork (AERONET)) during 6-14 October 2013. The instantaneous highest value of Aerosol Optical Depth (AOD) is observed to be 3.70 on 9 October 2013 followed by 3.12 on 8 October 2013. The primary cause of such high values is large scale crop residue burning and urban-industrial emissions in the study region. AERONET observations show daily mean AOD of 2.36 which is eight times higher than the observed values on normal day. The observed fine mode volume concentration is more than 1.5 times greater than the coarse mode volume concentration on the high aerosol burden day. We also find high values (~0.95) of Single Scattering Albedo (SSA) on 9 October 2013. Scatter-plot between AOD (500 nm) and Angstrom exponent (440-870 nm) reveals that biomass burning/urban-industrial aerosols are the dominant aerosol type on the heavy aerosol loading day over Lahore. MODIS fire activity image suggests that the areas in the southeast of Lahore across the border with India are dominated by biomass burning activities. A Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model backward trajectory showed that the winds at 1000 m above the ground are responsible for transport from southeast region of biomass burning to Lahore. CALIPSO derived sub-types of aerosols with vertical profile taken on 10 October 2013 segregates the wide spread aerosol burden as smoke, polluted continental and dust aerosols.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/LNO.10350", "year": 2016, "title": "Luminescence and density banding patterns in massive Porites corals around the Thai-Malay Peninsula, Southeast Asia", "abstract": "We characterized the annual luminescent and skeletal density banding patterns in 51 massive Porites corals from 15 reefs from six locations around the Thai-Malay Peninsula in Southeast Asia, and explored the seasonal environmental cues/drivers of band formation. Location-specific recurrent annual luminescent banding patterns were found at all study locations with a brighter band occurring toward the end of the year (October/November/December) (at five locations) and in June (one location). Annual density banding patterns could only be discerned at four locations, and were categorized into those that formed a dense band commencing November/December, and those starting May/June. Overall, compared to luminescence, variations in skeletal density provided a less clear signal for demarcation of annual growth increments. Seasonal variations in luminescence showed clearest relationships with salinity, as a proxy for freshwater/river runoff. No convincing relationship between intra-annual luminescence intensity and density variations was found, which supports the notion that luminescent banding is due to inclusions of fluorophores into the coral skeleton rather than variations in skeletal architecture. The relationships between seasonal density variations and significant wave height and rainfall suggest density banding in this region is likely related to wave energy, or some other correlated environmental parameter/s. The large variability in skeletal banding patterns not only highlights the current relatively poor understanding of their nature and causes, but also the need for replication in their interpretation, especially in settings with complex seasonal hydrodynamic/hydrological patterns such as those found around the Thai-Malay Peninsula.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.MARMICRO.2016.01.001", "year": 2016, "title": "Latitudinal distribution of extant fossilizable phytoplankton in the Southern Ocean: Planktonic provinces, hydrographic fronts and palaeoecological perspectives", "abstract": "We present the combined abundance of all extant fossilizable planktonic groups (Dinoflagellates, Coccolithophores, Silicoflagellates, Diatoms, Parmales, Archaeomonads and micro-zooplankton) from surface waters collected along a latitudinal transect in the western Pacific sector of the Southern Ocean, ranging from ~48S, offshore New Zealand, to ~70S in the Ross Sea, Antarctica. Latitudinal shifts in species' distribution correspond with the Antarctic Circumpolar Current fronts and with the seasonal position of the ice-edge. Distinct bioprovinces are defined by clustering samples with a high degree of similarity. Our data confirm the importance of previously-defined taxa as palaeoceanographic proxies but also reveal some differences: the shift in dominance between the silicoflagellates genera Dictyocha and Stephanocha, used as a proxy of palaeo sea-surface temperatures, occurs slightly north of the Southern Sub-Antarctic Front rather than at the Polar Front; the shifts in abundance between the open-ocean diatom species Fragilariopsis kerguelensis and sea-ice related F. curta and F. cylindrus, as well as the drop in the coccolithophore Emiliania huxleyi, occur at the southern Antarctic Circumpolar Front rather than at the Polar Front. Finally, we introduce the Corona-index, based on the ratio of the coronatid to non-coronatid silicoflagellates species Stephanocha speculum, as a new proxy for sea-ice and we confirm the occurrence of abundant Archaeomonads and Parmales (Triparma laevis subsp. ramispina) in the marginal ice-edge zone.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1021/ACS.EST.5B05193", "year": 2016, "title": "Influence of Climate Extremes and Land Use on Fecal Contamination of Shallow Tubewells in Bangladesh", "abstract": "Climate extremes in conjunction with some land use practices are expected to have large impacts on water quality. However, the impacts of land use and climate change on fecal contamination of groundwater has not been well characterized. This work quantifies the influences of extreme weather events and land use practices on Escherichia coli presence and concentration in groundwater from 125 shallow wells, a dominant drinking water resource in rural Bangladesh, monitored over a 17 month period. The results showed that E. coli presence was significantly associated with the number of heavy rain days, developed land and areas with more surface water. These variables also had significant impacts on E. coli concentration, with risk ratios of 1.38 (95% CI = 1.16, 1.65), 1.07 (95% CI: 1.05, 1.09), and 1.02 (95% CI = 1.01, 1.03), respectively. Significant synergistic effects on E. coli presence and concentration were observed when land use and weather variables were combined. The findings suggest that climate extremes and land use practices, particularly urbanization, might promote fecal contamination of shallow well water, thus increasing the risk of diarrheal diseases.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 14, "name": "Public Health" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ACP-16-8071-2016", "year": 2016, "title": "Global fine-mode aerosol radiative effect, as constrained by comprehensive observations", "abstract": "Abstract. Aerosols directly affect the radiative balance of the Earth through the absorption and scattering of solar radiation. Although the contributions of absorption (heating) and scattering (cooling) of sunlight have proved difficult to quantify, the consensus is that anthropogenic aerosols cool the climate, partially offsetting the warming by rising greenhouse gas concentrations. Recent estimates of global direct anthropogenic aerosol radiative forcing (i.e., global radiative forcing due to aerosolradiation interactions) are 0.35 0.5 W m2, and these estimates depend heavily on aerosol simulation. Here, we integrate a comprehensive suite of satellite and ground-based observations to constrain total aerosol optical depth (AOD), its fine-mode fraction, the vertical distribution of aerosols and clouds, and the collocation of clouds and overlying aerosols. We find that the direct fine-mode aerosol radiative effect is 0.46 W m2 (0.54 to 0.39 W m2). Fine-mode aerosols include sea salt and dust aerosols, and we find that these natural aerosols result in a very large cooling (0.44 to 0.26 W m2) when constrained by observations. When the contribution of these natural aerosols is subtracted from the fine-mode radiative effect, the net becomes 0.11 (0.28 to +0.05) W m2. This net arises from total (natural + anthropogenic) carbonaceous, sulfate and nitrate aerosols, which suggests that global direct anthropogenic aerosol radiative forcing is less negative than 0.35 W m2.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10592-016-0823-8", "year": 2016, "title": "Genetic population structure and low genetic diversity in the over-exploited sea cucumber Holothuria edulis Lesson, 1830 (Echinodermata: Holothuroidea) in Okinawa Island", "abstract": "Understanding genetic connectivity is fundamental for ecosystem-based management of marine resources. Here we investigate the metapopulation structure of the edible sea cucumber Holothuria edulis Lesson, 1830 across Okinawa Island, Japan. This species is of economic and ecological importance and is distributed from the Red Sea to Hawaii. We examined sequence variation in fragments of mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA (16S), and nuclear histone (H3) at six locations across Okinawa Island. We found higher haplotype diversity for mtDNA (COI: Hd = 0.69 and 16S: Hd = 0.67) and higher heterozygosity of nDNA (H3: HE = 0.39) in populations from the west coast of Okinawa compared to individuals from populations on the east coast (COI: Hd = 0.40; 16S: Hd = 0.21; H3: HE = 0.14). Overall population structure was significant (AMOVA results for COI: ST = 0.49, P ", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1021/ACS.EST.6B00351", "year": 2016, "title": "Fossil and Nonfossil Sources of Organic and Elemental Carbon Aerosols in the Outflow from Northeast China", "abstract": "Source quantification of carbonaceous aerosols in the Chinese outflow regions still remains uncertain despite their high mass concentrations. Here, we unambiguously quantified fossil and nonfossil contributions to elemental carbon (EC) and organic carbon (OC) of total suspended particles (TSP) from a regional receptor site in the outflow of Northeast China using radiocarbon measurement. OC and EC concentrations were lower in summer, representing mainly marine air, than in other seasons, when air masses mostly traveled over continental regions in Mongolia and northeast China. The annual-mean contribution from fossil-fuel combustion to EC was 76 11% (0.11.3 g m3). The remaining 24 11% (0.030.42 g m3) was attributed to biomass burning, with slightly higher contribution in the cold period (31%) compared to the warm period (21%) because of enhanced emissions from regional biomass combustion sources in China. OC was generally dominated by nonfossil sources, with an annual average of 66 11% (0.52.8 g m3), approximately half of which was apportioned to primary biomass-burning sources (34 6%). In winter, OC almost equally originated from primary OC (POC) emissions and secondary OC (SOC) formation from fossil fuel and biomass-burning sources. In contrast, summertime OC was dominated by primary biogenic emissions as well as secondary production from biogenic and biomass-burning sources, but fossil-derived SOC was the smallest contributor. Distinction of POC and SOC was performed using primary POC-to-EC emission ratios separated for fossil and nonfossil emissions.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.JVOLGEORES.2016.06.003", "year": 2016, "title": "Evidence of recent deep magmatic activity at Cerro Bravo-Cerro Machin volcanic complex, central Colombia. Implications for future volcanic activity at Nevado del Ruiz, Cerro Machin and other volcanoes", "abstract": "In the last nine years (20072015), the Cerro Bravo-Cerro Machin volcanic complex (CBCMVC), located in central Colombia, has experienced many changes in volcanic activity. In particular at Nevado del Ruiz volcano (NRV), Cerro Machin volcano (CMV) and Cerro Bravo (CBV) volcano. The recent activity of NRV, as well as increasing seismic activity at other volcanic centers of the CBCMVC, were preceded by notable changes in various geophysical and geochemical parameters, that suggests renewed magmatic activity is occurring at the volcanic complex. The onset of this activity started with seismicity located west of the volcanic complex, followed by seismicity at CBV and CMV. Later in 2010, strong seismicity was observed at NRV, with two small eruptions in 2012. After that, seismicity has been observed intermittently at other volcanic centers such as Santa Isabel, Cerro Espana, Paramillo de Santa Rosa, Quindio and Tolima volcanoes, which persists until today. Local deformation was observed from 2007 at NRV, followed by possible regional deformation at various volcanic centers between 2011 and 2013. In 2008, an increase in CO2 and Radon in soil was observed at CBV, followed by a change in helium isotopes at CMV between 2009 and 2011. Moreover, SO2 showed an increase from 2010 at NRV, with values remaining high until the present. These observations suggest that renewed magmatic activity is currently occurring at CBCMVC. NRV shows changes in its activity that may be related to this new magmatic activity. NRV is currently exhibiting the most activity of any volcano in the CBCMVC, which may be due to it being the only open volcanic system at this time. This suggests that over the coming years, there is a high probability of new unrest or an increase in volcanic activity of other volcanoes of the CBCMVC.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JASTP.2016.06.005", "year": 2016, "title": "Evaluation of the impact of atmospheric ozone and aerosols on the horizontal global/diffuse UV Index at Livorno (Italy)", "abstract": "A study was conducted at Livorno (Italy) to evaluate the impact of atmospheric aerosols and ozone on the solar UV radiation and its diffuse component at ground in clear sky conditions. Solar UV radiation has been quantified in terms of UV Index (UVI), following the ISO 17166:1999/CIE S007/E-1998 international standard. UVI has been calculated by exploiting the libRadtran radiative transfer modelling software as a function of both the Aerosols Optical Depth (AOD) and the Total Ozone Column (TOC). In particular AOD and TOC values have been remotely sensed by the Ozone Monitoring Instrument (OMI) on board the NASA's EOS (Earth Observing System) satellites constellation. An experimental confirmation was also obtained by exploiting global UVI ground-based measurements from the 26/9/14 to 12/8/15 and diffuse UVI ground-based measurements from the 17/5/15 to 12/8/15. For every considered value of Solar Zenith Angle (SZA) and atmospheric condition, estimates and measurements confirm that the diffuse component contributes for more than 50% on the global UV radiation. Therefore an exposure of human skin also to diffuse solar UV radiation can be potentially harmful for health and need to be accurately monitored, e.g. by exploiting innovative applications such as a mobile app with a satellite-based UV dosimeter that has been developed. Global and diffuse UVI variations due to the atmosphere are primarily caused by the TOC variations (typically cyclic): the maximum TOC variation detected by OMI in the area under study leads to a corresponding variation in global and diffuse UVI of about 50%. Aerosols in the area concerned, mainly of maritime nature, have instead weaker effects causing a maximum variation of the global and diffuse UVI respectively of 9% and 35% with an SZA of 20 and respectively of 13% and 10% with an SZA of 60.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1007/S11356-016-6953-1", "year": 2016, "title": "Column-integrated aerosol optical properties and direct radiative forcing over the urban-industrial megacity Nanjing in the Yangtze River Delta, China", "abstract": "Aerosol optical properties were measured and analyzed through the ground-based remote sensing Aerosol Robotic Network (AERONET) over an urban-industrial site, Nanjing (32.21 N, 118.72 E, and 62 m above sea level), in the Yangtze River Delta, China, during September 2007August 2008. The annual averaged values of aerosol optical depth (AOD500) and the Angstrom exponent (AE440870) were measured to be 0.94 0.52 and 1.10 0.21, respectively. The seasonal averaged values of AOD500 (AE440870) were noticed to be high in summer (autumn) and low in autumn (spring). The characterization of aerosol types showed the dominance of mixed type followed by the biomass burning and urban-industrial type of aerosol at Nanjing. Subsequently, the curvature (a2) obtained from the second-order polynomial fit and the second derivative of AE () were also analyzed to understand the dominant aerosol type. The single scattering albedo at 440 nm (SSA440) varied from 0.88 to 0.93 with relatively lower (higher) values during the summer (spring), suggesting an increase in black carbon and mineral dust (desert dust) aerosols of absorbing (scattering) nature. The averaged monthly and seasonal evolutions of shortwave (0.34.0 m) direct aerosol radiative forcing (DARF) values were computed from the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model both at the top of atmosphere (TOA) and bottom of atmosphere (SUR) during the study period. Further, the aerosol forcing efficiency (AFE) and the corresponding atmospheric heating rates (AHR) were also estimated from the forcing within the atmosphere (ATM). The derived DARF values, therefore, produced a warming effect within the atmosphere due to strong absorption of solar radiation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.JASTP.2016.01.017", "year": 2016, "title": "Atmospheric changes observed during April 2015 Nepal earthquake", "abstract": "A massive earthquake shook Nepal on 25 April 2015, with a moment magnitude of 7.9Mw, its hypocenter at a depth of 10km. Atmospheric changes that precede an earthquake might offer the hope of early warning and evacuation. Although the existence of such precursory signals is highly controversial, an attempt has been made to investigate the atmospheric changes from two months prior, to five months following this deadly earthquake. Aerosol optical depth (AOD) and columnar ozone were found to be higher by 40% and 6% respectively prior to the occurrence of the earthquake. The UV aerosol index (UVI), AOD and columnar NO2 increased, while columnar ozone and sea level pressure dropped following the earthquake.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JMARSYS.2016.02.012", "year": 2016, "title": "A survey of the summer coccolithophore community in the western Barents Sea", "abstract": "The Barents Sea is particularly vulnerable to large-scale hydro-climatic changes associated with the polar amplification of climate change. Key oceanographical variables in this region are the seasonal development of sea-ice and the location and strength of physico-chemical gradients in the surface and subsurface water layers induced by the convergence of Arctic- and Atlantic-derived water masses. Remote sensing imagery have highlighted the increasing success of calcifying haptophytes (coccolithophores) in the summer phytoplankton production of the Barents Sea over the last 20years, as a response to an overall larger contribution of Atlantic waters to surface and sub-surface waters, as well as to enhanced sea-ice melt-induced summer stratification of the photic layer. The present study provides a first thorough description of coccolithophore standing stocks and diversity over the shelf and slope of the western Barents Sea from two sets of surface and water column samples collected during AugustSeptember 2014 from northern Norway to southern Svalbard. The abundance and composition of coccolithophore cells and skeletal remains (coccoliths) are discussed in view of the physicalchemicalbiological status of the surface waters and water column based on in-situ (temperature, salinity, fluorescence) and shore-based (microscope enumerations, chemotaxonomy) measurements, as well as satellite-derived data (Chl a and particulate inorganic carbon contents). The coccolithophore population is characterized by a low species diversity and the overwhelming dominance of Emiliania huxleyi. Coccolithophores are abundant both within the well stratified, Norwegian coastal water influenced shallow mixed layer off northern Norway, as well as within well-mixed cool Atlantic water in close vicinity of the Polar Front. Bloom concentrations with standing stocks larger than 4million cells/l are recorded in the latter area north of 75N. Our limited set of chemotaxonomic data suggests that coccolithophores contribute substantially (ca. 20% of the total Chl a) to the summer phytoplankton community which is made essentially of small-sized algal groups. Excluding the bloom area, coccolith calcite accounts for an average of 20% to the bulk particulate inorganic carbon content in the surface waters, and explains to some extent the satellite-derived spatial distribution of this parameter. Deep water living coccolithophore species thriving below the pycnocline as well as populations present in well-mixed cool Atlantic water are rapidly transferred to depth in the form of intact coccospheres down to at least 200m. High amplitude internal waves which, according to our observations, affect a wide range of water depth up to the lower photic zone, might strengthen the vertical transfer of this sinking population.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S11869-016-0451-Y", "year": 2017, "title": "Variability of tropospheric columnar NO2 and SO2 over eastern Indo-Gangetic Plain and impact of meteorology", "abstract": "Long-term analyses of monthly mean tropospheric NO2 and SO2 were performed over a period of January 2005 to December 2014, around few industrial areas (power plant clusters) in the Indo-Gangetic Plains. Alongside, similar studies have been conducted over some background mountain and rural sites, forest areas and small urban locations without large industriesall located in and around the Indo-Gangetic Plains. In these locations, the trend analyses of columnar NO2 and SO2 using satellite-based measurements from Ozone Monitoring Instrument (OMI) were performed to study their spatial, seasonal and long-term behaviour. Distribution of NO2 shows a large variation with major hot spots and average monthly values ranging between 0.03 and 0.35 Dobson Unit (DU), whereas the same for SO2 illustrates the range of average monthly values in between 0.13 to 1.00 DU. All the columnar values have been further correlated to meteorological parameters like cloud fraction, rainfall, outgoing longwave radiation flux and planetary boundary layer height. Analysis of the results indicates the influence of meteorology on the columnar concentration of these gases. Anomalous behaviour of SO2 during 2008 and 2011 were observed due to the long-range transport of volcanic SO2 over India from Dalaffilla and Nabro volcanoes, respectively. SO2/NO2 ratio was also observed to elicit the contribution of stationary (power plants and industries) source origins over mobile (automobile) sources towards the columnar burdens of these gases.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 18, "name": "Volcanic Eruptions" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.RSE.2016.10.043", "year": 2017, "title": "Seasonal phytoplankton blooms in the Gulf of Aden revealed by remote sensing", "abstract": "The Gulf of Aden, situated in the northwest Arabian Sea and linked to the Red Sea, is a relatively unexplored ecosystem. Understanding of large-scale biological dynamics is limited by the lack of adequate datasets. In this study, we analyse 15years of remotely-sensed chlorophyll-a data (Chl-a, an index of phytoplankton biomass) acquired from the Ocean Colour Climate Change Initiative (OC-CCI) of the European Space Agency (ESA). The improved spatial coverage of OC-CCI data in the Gulf of Aden allows, for the first time, an investigation into the full seasonal succession of phytoplankton biomass. Analysis of indices of phytoplankton phenology (bloom timing) reveals distinct phytoplankton growth periods in different parts of the gulf: a large peak during August (mid-summer) in the western part of the gulf, and a smaller peak during November (mid-autumn) in the lower central gulf and along the southern coastline. The summer bloom develops rapidly at the beginning of July, and its peak is approximately three times higher than that of the autumnal bloom. Remotely-sensed sea-surface temperature (SST), wind-stress curl, vertical nutrient profiles and geostrophic currents inferred from the sea-level anomaly, were analysed to examine the underlying physical mechanisms that control phytoplankton growth. During summer, the prevailing southwesterlies cause upwelling along the northern coastline of the gulf (Yemen), leading to an increase in nutrient availability and enhancing phytoplankton growth along the coastline and in the western part of the gulf. In contrast, in the central region of the gulf, lowest concentrations of Chl-a are observed during summer, due to strong downwelling caused by a mesoscale anticyclonic eddy. During autumn, the prevailing northeasterlies enable upwelling along the southern coastline (Somalia) causing local nutrient enrichment in the euphotic zone, leading to higher levels of phytoplankton biomass along the coastline and in the lower central gulf. The monsoon wind reversal is shown to play a key role in controlling phytoplankton growth in different regions of the Gulf of Aden.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/S10584-016-1878-8", "year": 2017, "title": "Global warming and local air pollution have reduced wheat yields in India", "abstract": "We use regression analysis on data from 208 districts over the period 19812009 to examine the impact of temperature and solar radiation (affected by pollution from aerosols) on wheat yields in India. We find that a 1 C increase in average daily maximum and minimum temperatures tends to lower yields by 24% each. A 1% increase in solar radiation increases yields by nearly 1%. Yields are estimated to be about 5.2% lower than they would have been if temperatures had not increased during the study period. We combine the estimated impacts of weather on yield with the estimated impacts of aerosol pollution (measured by moderate resolution imaging spectroradiometer sensor in terms of aerosol optical depth, aerosol optical depth (AOD) in 20012013) on weather to compute the net impact of reducing aerosol pollution on wheat yields. A one-standard-deviation decrease in AOD is estimated to increase yields by about 4.8%. Our results imply reducing regional pollution and curbing global warming in the coming decades can counter wheat yield losses.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2019GL084589", "year": 2019, "title": "Subsurface Water Dominates Sierra Nevada Seasonal Hydrologic Storage", "abstract": "Vertical displacements (dz) in permanent Global Positioning System (GPS) station positions enable estimation of water storage changes (S), which historically have been impossible to measure directly. We use dz from 924 GPS stations in the western United States to estimate daily S in California's Sierra Nevada and compare it to seasonal snow accumulation and melt over water years 20082017. Seasonal variations in GPS-based S are 1,000 mm. Typically, only 30% of S is attributable to snow water equivalent (SWE). S lags the snow cycle, peaking after maximum SWE and remaining positive when all snow has melted (SWE = 0). We conclude that seasonal S fluctuations are not primarily driven by SWE but by rainfall and snowmelt stored in the shallow subsurface (as soil moisture and/or groundwater) and released predominantly through evapotranspiration. Seasonal peak GPS S is larger than accumulated precipitation from the Parameter-elevation Relationships on Independent Slopes Model and North American Land Data Assimilation System, indicating that these standard inputs underestimate mountain precipitation.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S11869-019-00709-5", "year": 2019, "title": "Springtime warming and biomass burning causing ozone episodes in South and Southwest China", "abstract": "A detailed analysis of springtime ozone outbreaks in South/Southwest China is presented in this paper, providing an insight into a regional photochemical and climate problem. A major ozone episode in 2013 was the first ever in April and the worst in Hong Kong up to 2018, measuring a peak ozone concentration of 293 g m3. This multi-day, ozone pollution was evidenced by similar conditions in the Pearl River Delta (PRD), and an even more severe episode in Kunming (Yunnan) in Southwest China. Concurrently, widespread air temperature composite anomalies of up to about + 4K were observed in the region, particularly during 6Z (14:00 local time). The global annual geopotential height anomaly implied increased atmospheric stability and inhibited dispersionconsistent with global warming impacts for the region. Backward trajectories, satellite observations, and transport model simulations characterized the biomass burning sources. Results indicated that activities in Indochina, South and Southwest China, and Africa were the main sources in South China while those in Burma dominated Southwest China. The close succession of outbreaks from west to east (Kunming, Guangzhou, and Hong Kong) suggests an eastward transport of ozone and precursors.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.22059/POLL.2018.260252.463", "year": 2019, "title": "Monitoring of SO2 column concentration over Iran using satellite-based observations during 2005-2016", "abstract": "For the first time, sulfur dioxide concentration was monitored between 2005 and 2016 over Iran which is among the countries with a high SO2 emission rate in the world. To that end, SO2 column concentration at Planetary Boundary Layer (PBL) from Ozone Monitoring Instrument (OMI) was analyzed. OMI is a sensor onboard the Aura satellite which can measure daily SO2 concentration on the global scale. From OMI maps, 19 notable SO2 hotspots were detected over Iran. The results indicate that the most elevated level of SO2 among these 19 hotspots belong to Khark Island and Asaluye in Bushehr province, southwest of Iran. Annual trend analysis shows that SO2 concentration has been slightly augmented during 2005-2016 over this country. Distribution analysis of SO2 concentration over Iran showed that the most polluted provinces are Bushehr, Khuzestan and Ilam lied in the southwest of Iran. On the contrary, the lowest level of SO2 has observed over northwest of Iran at West and East Azerbaijan and Ardabil provinces. The correlation coefficient between total energy production in Iran and SO2 concentration from 2005 to 2016 is as high as ~0.7. Hence, it can be derived that energy production, most notably production of crude oil, plays a pivotal role in SO2 concentration over Iran.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S00445-019-1312-Y", "year": 2019, "title": "Identifying eruptive sources of drifting volcanic ash clouds using back-trajectory modeling of spaceborne thermal infrared data", "abstract": "A new approach is presented for determining the source region of disconnected volcanic ash clouds using a combination of orbital thermal infrared (TIR) image data, HYSPLIT-generated backward trajectories, and spatial geostatistics. Interpolated surfaces derived from the TIR data are created to find the most likely ash cloud travel path and the potential source volcanoes identified from that path. The ability to use backward trajectories to determine the ash cloud source region will become an important triggering tool to target high spatial resolution orbital sensors, which normally rely on thermal anomalies for new targeting. During cases where thermal anomalies are not present or masked by meteorological cloud, ash cloud detection and predicted source location become more important. Image data from several well-documented past eruptions are presented to validate and determine the overall accuracy of this technique. Because this is seen as a limited range source region validation tool, the ash clouds examined were ", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3897/NATURECONSERVATION.34.30732", "year": 2019, "title": "Interannual variability of vertical particle fluxes in the Ross Sea (Antarctica)", "abstract": "This study presents new data on biogenic and terrigenous particle fluxes collected by an oceanographic mooring (Mooring A) deployed in the south-western Ross Sea (Antarctica) in the frame of the Italian Long-Term Ecological Research network (LTER-Italy). Results from the years 2005 and 2008 document high mass fluxes during the summer and early autumn seasons, not coincident with the algal bloom. Downward particle fluxes exhibit a high inter-annual variability of both particulate fluxes and composition that seem related to the different factors as the phytoplankton increases, occurring between the beginning of February and the end of March, to the variations in the sea ice extent and to the resuspension and/or lateral advection processes. The flux variability may have been influenced by Iceberg B-15 that resided in the investigated area between 2000 and 2005. The decoupling of biogenic silica and organic carbon cycles is documented by differences in the rates of their respective key processes: biogenic silica dissolution and organic carbon degradation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.CHEMGEO.2018.11.024", "year": 2019, "title": "The distribution of neodymium isotopes and concentrations in the eastern tropical North Atlantic", "abstract": "Dissolved neodymium (Nd) and its radiogenic isotope composition (143Nd/144Nd, expressed as Nd) belong to the key parameters of the international GEOTRACES program, which aims to investigate the processes controlling the distribution of trace elements and their isotopes in the global ocean. We present Nd isotope and concentration ([Nd]) data from eleven full depth water column profiles from the eastern (sub)tropical Atlantic Ocean between 2N and 29N and from the Romanche Fracture Zone sampled during Meteor cruise M81/1 (GEOTRACES cruise GA11) in February/March 2010. The Nd signatures range from 12.9 in upper North Atlantic Deep Water (UNADW) at the equator to 8.1 in the mixed layer near the Canary Islands. Nd concentrations range from 11.9 pmol/kg observed within the Equatorial Undercurrent to 40.2 pmol/kg in Antarctic Bottom Water (AABW) in the Romanche Fracture Zone. Large variations in surface water Nd isotope compositions (12.7 Nd 8.1) and concentrations (15.7 pmol/kg [Nd] 27.7 pmol/kg) are caused by partial dissolution of Saharan dust particles between 2N and 13N and volcanic island weathering (Canaries) between 25N and 29N. In contrast to dust inputs, which predominantly affect the Nd concentrations and isotope compositions of surface waters and underlying South Atlantic Central Water (SACW), contributions originating from the Canary Islands affect the Nd isotope composition of the entire surrounding water column without significantly altering Nd concentrations, thus confirming the concept of boundary exchange in its strictest sense. The results confirm that the composition of lower North Atlantic Deep Water (LNADW, Nd = 12.1) in the abyssal plains of the eastern North Atlantic is exclusively set by the mixing ratio of LNADW and Antarctic Bottom Water (AABW). Upper North Atlantic Deep Water (UNADW), in contrast, is characterized by Nd signatures between 12.7 and 12.0 between 2N and 10N, whereas further north it is clearly affected by admixture of Mediterranean Water (MW) and radiogenic inputs from the Canary Islands and likely also the Cape Verde Islands. This article is part of a special issue entitled: Cycles of trace elements and isotopes in the ocean GEOTRACES and beyond - edited by Tim M. Conway, Tristan Horner, Yves Plancherel, and Aridane G. Gonzalez.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.CSR.2019.104005", "year": 2019, "title": "Characterizing the influence of Atlantic water intrusion on water mass formation and phytoplankton distribution in Kongsfjorden, Svalbard", "abstract": "Warm water intrusion into Arctic fjords is increasingly affecting polar ecosystems. This study investigated how Atlantic water intrusion and tidewater glacial melting impacted water mass formation and phytoplankton distribution in Kongsfjorden, Svalbard. Field data were collected over a 2-week period during the height of the melt season in August 2014 and were contextualized within an 18-year regional MODIS satellite record. Since 1998, intruding waters have warmed by 45.5 C, which has prevented sea ice formation and changed the characteristics of fjord bottom waters. Modeled light fields suggest that suspended sediment in this glacial meltwater has reduced the euphotic zone close to the ice face, contributing to lower phytoplankton concentrations in both persistent and intermittently sediment-laden meltwater plumes. However, measurements collected close to terrestrially terminating glaciers indicate that turbidity is significantly lower in the meltwater plumes, resulting in deep euphotic zones and high phytoplankton concentrations. The results of this study support a three-part conceptual model of the effects of warm-water intrusion on water mass formation and primary production within 10 km of tidewater glaciers. Initially, warm water intrusion reduces sea ice coverage, which increases the euphotic depth and increases phytoplankton biomass. Warm water intrusions may also result in increased melting of tidewater glaciers, enhanced sediment release, reduction in euphotic depth and reduction in phytoplankton biomass. Ultimately, as tidewater glaciers retreat and become terrestrially terminating, the sediment load decreases, the euphotic zone again increases, and phytoplankton biomass increases.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.2174/1874282301711010121", "year": 2017, "title": "MODIS Summer SUHI Cross-sections Anomalies over the Megacities of the Monsoon Asia Region and Global Trends", "abstract": "Background:\n Evidence has accumulated in recent years regarding the scope of local and global climate changes attributed to exacerbating anthropogenic factors such as accelerating population growth, urbanization, industrialization, traffic and energy use. Remote space monitoring, unlike ground-based measurements, has the advantage of providing global coverage on a daily basis.\n \n \n Methods:\n MODIS (Moderate Resolution Imaging Spectroradiometer) Aqua and Terra 11 spatial resolution as well as the 1 km higher resolution of Aqua-MODIS were investigated for a global overview of megacities temperature variations, as well as the recent trends of the 10 largest Monsoon Asian megacities.\n \n \n Results:\n The average Land Surface Temperature (LST) cross-sections of the 10 Asian megacities were examined for June-August 2002-2014. Temperature variations fit a spatial bell-shaped curve, with a pronounced maximum over the city center. Nighttime data indicated sharp LST decreases with distance from the city center, particularly in the coldest cities, those of Tokyo, Seoul, Osaka and Beijing.\n \n \n Conclusion:\n \n Daytime latitudinal (E-W) and longitudinal (N-S) Surface Urban Heat Islands (SUHI) have steeper gradients than for nighttime data. During daytime, the SUHI gradients are largest in Tokyo, Seoul, Osaka and Beijing with values reaching 15\n o\n C followed by the cities of Shanghai and Guangzhou with ~11\n o\n C, and Karachi with ~5\n o\n C SUHI. Nighttime SUHIs were more moderate, 4-6\n o\n C in Tokyo, Seoul ~5\n o\n C, Osaka 5-7\n o\n C and Beijing ~7\n o\n C. Only in the three largest megacities,\n i.e.\n , Tokyo, Guangzhou and Shanghai, did the nighttime LST trends decline.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.117738", "year": 2020, "title": "Assessment of dominating aerosol properties and their long-term trend in the Pan-Third Pole region: A study with 10-year multi-sensor measurements", "abstract": "The Pan-Third Pole (PTP), stretching from Eastern Asia to Middle-central Europe, has experienced unprecedented accelerated warming and even retreat of glaciers. Absorbing aerosols reduce snow and ice albedo and radiative forcing, consequently enhancing a great melting of snow cover and ice sheet in the PTP. Employing the 10-year (20072016) space-based active and passive measurements, this study investigated the distribution, optical properties and decadal trends for dominating aerosols at a seasonal scale in the PTP divided into six sub-regions. Results showed that the sub-regions of PTP were mainly dominated by dust, polluted dust and elevated smoke. The Taklimakan Desert (TD) and the Iranian Plateau (IP) were dominated by mineral dust, accounting for 96% and 86% of the total aerosol extinction while the Central Europe (CE), Indo-China (IC) and Anatolia Plateau (AP) were dominated by the mixture of the dominating aerosol types. The mean aerosol extinction coefficient (MAEC) showed an obvious variability depending on the sub-regions and a tendency of decreasing with an increase in the topographic height. The strongest extinction layer (>0.1 km1) mainly occurred below 4 km and the weak extinction layers (>0.001 km1) were mainly distributed between 5 km and 8 km, indicating pronounced vertical transport in the region. The decadal trends of columnar aerosol optical depth (AOD) showed a relation with the contributions of the dominating aerosol types. For example, significant upward or downward trends of total aerosol loading in the IC region were driven by elevated smoke while the AOD trends of total aerosol loading for the CE, the AP and the IP were driven by the dominating aerosol types. The Tibetan Plateau (TP), the cleanest region in the PTP, has been regularly exposed to polluted air masses with significant amounts of absorbing aerosols. Therefore, understanding the dominating aerosol types, properties and decadal trends in the PTP region will contribute considerably to assessing their effects on radiative forcing, climate change, and even snowmelt and glacier retreat.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.CSR.2018.08.006", "year": 2018, "title": "To what extents are species richness and abundance of reef fishes along a tropical coast related to latitude and other factors?", "abstract": "This study has employed an integrated statistical approach to determine the extents to which species richness and abundance (catch rate) of fishes over reefs along an extensive coastline were related to various factors. Fish were thus sampled by trapping over deep (~ 22 m) and shallow (~ 12 m) reefs along the ~ 1500 km tropical coast of north-western Australia (NWA). Fish were caught during day and night in both dry and wet seasons at two well-spaced locations in each of the Kimberley (1316S), Canning (1619S) and Pilbara (2022S) bioregions. Species richness and abundance were both typically less at the two locations at the lowest latitude than at the two at the highest latitudes. This trend, which contrasts with the paradigm regarding latitudinal trends for these biotic variables, is attributable to the far more extreme hydrological conditions in the Kimberley than Pilbara. Indeed, both biotic variables peaked in the Canning, presumably reflecting, inter alia, the better development of reef and suspension feeder habitats in that bioregion. The peak in abundance was attributable to particularly high numbers of the NWA endemic Lethrinus punctulatus. A greater species richness and abundance of fishes in deeper than shallow water during the wet season, and particularly in areas of greater cyclonic activity, reflect the movement of species such as Lethrinus laticaudis and Lutjanus carponotatus from shallow to calmer, deeper waters. These two biotic variables were greater during the day than night, with a greater number and abundance of diurnally-active species, e.g. lethrinids, feeding overall in the traps than is the case with nocturnal species, e.g. lutjanids. The results imply that the typical poleward latitudinal gradients in species richness and abundance are over-ridden along the NWA coast by environmental differences among bioregions.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-17-13119-2017", "year": 2017, "title": "Frequent ultrafine particle formation and growth in Canadian Arctic marine and coastal environments", "abstract": "Abstract. The source strength and capability of aerosol particles in the Arctic to act as cloud condensation nuclei have important implications for understanding the indirect aerosolcloud effect within the polar climate system. It has been shown in several Arctic regions that ultrafine particle (UFP) formation and growth is a key contributor to aerosol number concentrations during the summer. This study uses aerosol number size distribution measurements from shipboard expeditions aboard the research icebreaker CCGS Amundsen in the summers of 2014 and 2016 throughout the Canadian Arctic to gain a deeper understanding of the drivers of UFP formation and growth within this marine boundary layer. UFP number concentrations (diameter > 4 nm) in the range of 101104 cm3 were observed during the two seasons, with concentrations greater than 103 cm3 occurring more frequently in 2016. Higher concentrations in 2016 were associated with UFP formation and growth, with events occurring on 41 % of days, while events were only observed on 6 % of days in 2014. Assessment of relevant parameters for aerosol nucleation showed that the median condensation sink in this region was approximately 1.2 h1 in 2016 and 2.2 h1 in 2014, which lie at the lower end of ranges observed at even the most remote stations reported in the literature. Apparent growth rates of all observed events in both expeditions averaged 4.3 4.1 nm h1, in general agreement with other recent studies at similar latitudes. Higher solar radiation, lower cloud fractions, and lower sea ice concentrations combined with differences in the developmental stage and activity of marine microbial communities within the Canadian Arctic were documented and help explain differences between the aerosol measurements made during the 2014 and 2016 expeditions. These findings help to motivate further studies of biosphereatmosphere interactions within the Arctic marine environment to explain the production of UFP and their growth to sizes relevant for cloud droplet activation.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ANGEO-2019-138", "year": 2019, "title": "Statistical analysis of the long-range transport of the 2015 Calbuco volcanic eruption from ground-based and space-borne observations", "abstract": "Abstract. This study investigates the influence of the 2015 Calbuco eruption (41.2 S, 72.4 W; Chile) on the total columnar aerosol optical properties over the Southern Hemisphere. The well-known technic of sunphotometry was applied for investigation of the transport and the spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sunphotometer measurements performed at 6 South American and 3 African sites were statistically analyzed. This study involves the use of the satellite observations and a back-trajectory model. The passage of the Calbuco plume is statistically detectable on the aerosol optical depth (AOD) observations obtained from sunphotometers and MODIS. This statistical detection confirms that the majority of the plume was transported over the northeastern parts of South America and reached the South African region one week following the eruption. The plume has impacted to a lesser extent the southern parts of South America. The highest AOD anomalies were observed over the northeastern parts of the South America. Over the South African sites, the AOD anomalies induced by the spread of the plume were quite homogeneously distributed between the east and west coast. The optical characteristics of the plume near source region was consistent with a bearing-ash plume. Conversely, the remote sites to the Calbuco volcano were influenced by ash-free plume. The optical properties discuss on this paper will be used as inputs for numerical models for further investigation on the ageing of the Calbuco plume in a forthcoming study.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.RENENE.2017.04.043", "year": 2017, "title": "Statistical analysis and inter-comparison of erythemal solar radiation for Athalassa and Larnaca, Cyprus", "abstract": "A statistical analysis and inter-comparison of the erythemal ultraviolet radiation (UVER) at two sites in Cyprus representing two different climate regimes of the island (Athalassa-inland plain vs Larnaca-coastal location) covering the period January 2013December 2015 is presented. Mean annual and mean monthly daily totals of the UVER irradiation and their frequency distribution at both sites are computed and discussed. UVER irradiance fluctuates between 0.054 W m2 in December to 0.227 W m2 in July at solar noon at Athalassa. The values at Larnaca are lower than in Athalassa and they fluctuate between 0.043 W m2 in December and 0.172 W m2 in July at solar noon. The total accumulated UVER irradiation along a mean year reaches 1142 kJ m2 at Athalassa and 909 kJ m2 at Larnaca. Large fluctuations of the daily UVER irradiation are observed in the spring months and November, which are mainly due to unstable meteorological conditions during the transition from cold to warm weather and vice versa. During summer the daily UVER radiation exceeds the value of 6 kJ m2 at Athalassa and 4.8 kJ m2 at Larnaca, while during the winter season the lowest is about 0.2 kJ m2 at both sites. Statistical relationships between UVER and other radiation components (UVA, global radiation, clearness index and relative optical air mass) are established. The UV Index reaches high (67) or very high (810) values in 58.1% of the cases in Athalassa, whereas in Larnaca these values are reached in 38.8%. It is observed that the cumulative doses of UVER during an average year range from 9087 Standard Erythemal Dose (SEDs) in Larnaca to 11418 SEDs in Athalassa. The most common skin type in Cyprus, phototype III (about 70% of the population), could receive an annual cumulative dose between 2596 Minimum Erythemal Doses (MEDs) in Larnaca to 3262 MEDs in Athalassa.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/SU11051410", "year": 2019, "title": "Can We Detect the Brownness or Greenness of the Congo Rainforest Using Satellite-Derived Surface Albedo? A Study on the Role of Aerosol Uncertainties", "abstract": "The ability of spatial remote sensing in the visible domain to properly detect the slow transitions in the Earths vegetation is often a subject of debate. The reason behind this is that the satellite products often used to calculate vegetation indices such as surface albedo or reflectance, are not always correctly decontaminated from atmospheric effects. In view of the observed decline in vegetation over the Congo during the last decade, this study investigates how effectively satellite-derived variables can contribute to the answering of this question. In this study, we use two satellite-derived surface albedo products, three satellite-derived aerosol optical depth (AOD) products, two model-derived AOD products, and synthetic observations from radiative transfer simulations. The study discusses the important discrepancies (of up to 70%) found between these satellite surface albedo products in the visible domain over this region. We conclude therefore that the analysis of trends in vegetation properties based on satellite observations in the visible domain such as NDVI (normalized difference vegetation index), calculated from reflectance or albedo variables, is still quite questionable over tropical forest regions such as the Congo. Moreover, this study demonstrates that there is a significant increase (of up to 14%) in total aerosols within the last decade over the Congo. We note that if these changes in aerosol loads are not correctly taken into account in the retrieval of surface albedo, a greenness change of the surface properties (decrease of visible albedo) of around 8% could be artificially detected. Finally, the study also shows that neglecting strong aerosol emissions due to volcano eruptions could lead to an artificial increase of greenness over the Congo of more than 25% in the year of the eruptions and up to 16% during the 23 years that follow.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1002/JOC.6191", "year": 2020, "title": "Climate trends in the East Antilles Islands", "abstract": "This paper analyzes climate trends in satellite-blended model reanalyses for the east Antilles islands of Guadeloupe, Dominica and Martinique (1417N, 62.560.5W). Trends are studied for the dry winter (JFM) and wet summer (JAS) seasons, for parameters including: aerosol profile, tropospheric NO2 concentration, rainfall and hydrology, outgoing longwave radiation, potential evaporation, sea level, air and sea temperature and salinity in the upper ocean. Climate change emerges in the form of 24 and 68-year surges in near-surface temperature and mid-tropospheric subsidence. While near-surface specific humidity exhibits a rising trend especially in summer, the mid-troposphere is drying. Coastal zones show little trend in rainfall, but cloud forests on the volcanic slopes are getting wetter. Faster rising trends are noted for sea surface height, and for sea temperatures in low salinity zones that affect tropical cyclone intensification. This work quantifies the spatial and temporal nature of climate variability in the east Antilles islands of Guadeloupe, Dominica and Martinique and advocates for increasing integration of mesoscale analysis into studies on local socio-economic vulnerability.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS9070277", "year": 2018, "title": "Changes in Haze Trends in the Sichuan-Chongqing Region, China, 1980 to 2016", "abstract": "This study analyzed the long-term variations and trends of haze pollution and its relationships with emission and meteorological factors using the haze days (HDs) data derived from surface observation stations in Sichuan-Chongqing (SCC) region during 19802016. The results showed that the multi-year mean number of HDs were 68.7 and 4.9 days for the Sichuan-Basin (SCB) and the rest of SCC region, respectively. The seasonally averaged HDs over SCB reached its maximum in winter (34.7 days), followed by autumn (17.0 days) and spring (11.6 days), and with the minimum observed in summer (5.5 days). The inter-annual variations of HDs in 18 main cities revealed that Zigong, Neijiang, and Yibin, which are located in the southern of SCB, have been the most polluted areas over the SCC region in the past decades. A notable increasing trend in annual HDs over the majority of SCC region was found during 19801995, then the trend sharply reversed during 19962005, while it increased, fluctuating at some cities after 2006. Seasonally, the increased trend in spring and autumn seems to be the strongest during 19801995, whereas the decreased trend in spring and winter was stronger than other seasons during 19962005. In addition, a remarkable increasing trend was found in winter since 2006. Using correlation analysis between HDs and emission and meteorological factors during different periods, we found that the variability of local precipitation days (PDs), planetary boundary layer height (PBLH), near-surface wind speed (WS), and relatively humidity (RH) play different roles in influencing the haze pollution change during different historical periods. The joint effect of sharp increase of anthropogenic emissions, reduced PDs and WS intensified the haze pollution in SCB during 19801995. In contrast, decreased HDs during 19962005 are mainly attributable to the reduction of PM2.5 emission and the increase of PDs (especially in winter). In addition, the decrease of PDs is likely to be responsible for the unexpected increase in winter HDs over SCB in the last decade.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S11769-017-0922-6", "year": 2017, "title": "Characteristics and cause analysis of heavy haze in Changchun City in Northeast China", "abstract": "Northeast China has been reported as having serious air pollution in China with increasing occurrences of severe haze episodes. Changchun City, as the center of Northeast China, has longstanding industry and is an important agricultural base. Additionally, Changchun City has a long winter requiring heating of buildings emitting pollution into the air. These factors contribute to the complexity of haze pollution in this area. In order to analyze the causes of heavy haze, surface air quality has been monitored from 2013 to 2015. By using satellite and meteorological data, atmospheric pollution status, spatio-temporal variations and formation have been analyzed. Results indicated that the air quality in 88.9% of days exceeding air quality index (AQI) level-1 standard (AQI >50) according to the National Ambient Air Quality Standard (NAAQS) of China. Conversely, 33.7% of the days showed a higher level with AQI > 100. Extreme haze events (AQI > 300) occurred frequently during agricultural harvesting period (from October 10 to November 10), intensive winter heating period (from Late-December to February) and period of spring windblown dust (April and May). Most daily concentrations of gaseous pollutants, i.e., NO2 (43.8 g/m3), CO (0.9 mg/m3), SO2 (37.9 g/m3), and O3 (74.9 g/m3) were evaluated within level-1 concentration limits of NAAQS standards. However, particulate matter (PM2.5 and PM10) concentrations (67.3 g/m3and 115.2 g/m3, respectively) were significantly higher than their level-1 limits. Severe haze in spring was caused by offsite transported dust and windblown surface soil. Heavy haze periods during fall and winter were mainly formed by intensive emissions of atmospheric pollutants and steady weather conditions (i.e., low wind speed and inversion layer). The overlay emissions of widespread straw burning and coal combustion for heating were the dominant factors contributing to haze in autumn, while intensive coal burning during the coldest time was the primary component of total emissions. In addition, general emissions including automobile exhaust, road and construction dust, residential and industrial activities, have significantly increased in recent years, making heavy haze a more frequent occurrence. Therefore, both improved technological strategies and optimized pollution management on a regional scale are necessary to minimize emissions in specified seasons in Changchun City, as well as comprehensive control measures in Northeast China.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.GEOMORPH.2020.107317", "year": 2020, "title": "The long-term evolution of landslide activity near the epicentral area of the 2008 Wenchuan earthquake in China", "abstract": "The Wenchuan earthquake triggered numerous landslides and damaged vast areas of vegetation. Strong mountain earthquakes have long-term impacts on the activities of subsequent landslides. It is crucial for long-term geohazard risk assessment to investigate the spatio-temporal evolution of post-earthquake landslides. We used multi-year images from 2008 to 2018 to track the reactivation of coseismic landslides and newly occurring landslides to evaluate the influence of the Wenchuan earthquake on subsequent rain-induced landslides. With the aid of a GIS platform combined with field investigations, we analyzed the temporal and spatial evolutions of landslide activities over the past ten years and the factors controlling these changes. In addition, the process of vegetation recovery at landslide sites in the epicentral area was detected based on multi-year Landsat TM data after the Wenchuan earthquake. We observed that the total area of active landslides decreased significantly with time. In the first 5 years (20082013), the vegetation recovered quickly but was not well rehabilitated, and post-seismic landslides generally maintained high activity levels. Due to progressive revegetation and consolidation, most of the coseismic deposits along the hillslopes gradually stabilized. Subsequently (20132018), landslide activity weakened and mainly occurred in high and steep areas with poor vegetation recovery, particularly in proximity to the drainage network. Decreasing occurrence of rain-induced landslides was closely related to vegetation recovery in both time and space, and vegetation recovery could promote the reduction in post-earthquake landslide activities. We also proposed a quantitative model for the landslide rate in the epicentral area of the Wenchuan earthquake, which shows that the enhanced landslide rate reached its peak after the earthquake and will decrease to the pre-earthquake level in 25 years. The evolution of the post-seismic landslide activity can be categorized into four stages: high active period (20082013), low active period (20132018), recovery period (20182033), and stable period (after 2033).", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.134585", "year": 2020, "title": "Monitoring drought using composite drought indices based on remote sensing", "abstract": "Drought is one of the most frequent disasters occurring in North China and has a great influence on agriculture, ecology and economy. To monitor drought of typical dry areas in North China, Shandong Province, this paper proposed composite drought indices using multivariable linear regression (MCDIs) to integrate Tropical Rainfall Measuring Mission (TRMM) derived precipitation, Global Land Data Assimilation System Version 2.1 (GLDAS-2.1) derived soil moisture, Moderate Resolution Imaging Spectroradiometer (MODIS) derived land surface temperature (LST) and normalized difference vegetation index (NDVI) from 2013 to 2017 (March to September). Pearson correlation analyses were performed between single remote sensing drought indices and in-situ drought indices, standardized precipitation evapotranspiration index (SPEI), in different time scales to assess the capability of single indices over Shandong Province. The multivariable linear regression method was used to established MCDIs, and mediator and moderator variables were introduced to optimize the model. The correlation coefficients (r) between MCDIs and SPEIs was higher than that between each single index and SPEIs. Additionally, when we investigate the correlations of different MCDIs with both standardized precipitation index (SPI) and moisture index (MI), the highest r values with both 1-month SPI and MI were acquired by the MCDI based on 1-month SPEI (MCDI-1). This suggested MCDI-1 was suitable to monitor meteorological drought. Also, the comparison between MCDI based on 9-month SPEI (MCDI-9) and soil moisture showed MCDI-9 was a good indicator for agricultural drought. Therefore, multivariable linear regression and MCDIs were recommended to be an effective method and indices for monitoring drought across Shandong Province and similar areas.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5194/ACP-18-16439-2018", "year": 2018, "title": "Lower tropospheric ozone over the North China Plain: variability and trends revealed by IASI satellite observations for 20082016", "abstract": "Abstract. China is a highly polluted region, particularly the North China Plain (NCP). However, emission reductions have been occurring in China for about the last 10 years; these reduction measures have been in effect since 2006 for SO2 emissions and since 2010 for NOx emissions. Recent studies have shown a decrease in the NO2 tropospheric column since 2013 that has been attributed to the reduction in NOx emissions. Quantifying how these emission reductions translate regarding ozone concentrations remains unclear due to apparent inconsistencies between surface and satellite observations. In this study, we use the lower tropospheric (LT) columns (surface 6 km a.s.l. above sea level) derived from the IASI-A satellite instrument to describe the variability and trend in LT ozone over the NCP for the 20082016 period. First, we investigate the IASI retrieval stability and robustness based on the influence of atmospheric conditions (thermal conditions and aerosol loading) and retrieval sensitivity changes. We compare IASI-A observations with the independent IASI-B instrument aboard the Metop-B satellite as well as comparing them with surface and ozonesonde measurements. The conclusion from this evaluation is that the LT ozone columns retrieved from IASI-A are reliable for deriving a trend representative of the lower/free troposphere (35 km). Deseasonalized monthly time series of LT ozone show two distinct periods: the first period (20082012) with no significant trend (<0.1 % yr1) and a second period (20132016) with a highly significant negative trend of 1.2 % yr1, which leads to an overall significant trend of 0.77 % yr1 for the 20082016 period. We explore the dynamical and chemical factors that could explain these negative trends using a multivariate linear regression model and chemistry transport model simulations to evaluate the sensitivity of ozone to the reduction in NOx emissions. The results show that the negative trend observed from IASI for the 20132016 period is almost equally attributed to large-scale dynamical processes and emissions reduction, with the large El Nino event in 20152016 and the reduction of NOx emissions being the main contributors. For the entire 20082016 period, large-scale dynamical processes explain more than half of the observed trend, with a possible reduction of the stratospheretroposphere exchanges being the main contributor. Large-scale transport and advection, evaluated using CO as a proxy, only contributes to a small part of the trends (10 %). However, a residual significant negative trend remains; this shows the limitation of linear regression models regarding their ability to account for nonlinear processes such as ozone chemistry and stresses the need for a detailed evaluation of changes in chemical regimes with the altitude.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/IJERPH17010229", "year": 2020, "title": "Spatiotemporal Variations and Factors of Air Quality in Urban Central China during 20132015", "abstract": "Spatiotemporal behaviors of particulate matter (PM2.5 and PM10) and trace gases (SO2, NO2, CO, and O3) in Hefei during the period from December 2013 to November 2015 are investigated. The mean annual PM2.5 (PM10) concentrations are 89.1 59.4 g/m3 (118.9 66.8 g/m3) and 61.6 32.2 g/m3 (91.3 40.9 g/m3) during 2014 and 2015, respectively, remarkably exceeding the Chinese Ambient Air Quality Standards (CAAQS) grade II. All trace gases basically meet the requirements though NO2 and O3 have a certain upward trend. Old districts have the highest pollution levels, followed by urban periphery sites and new districts. Severe haze pollution occurs in Hefei, with frequent exceedances in particulate matter with 178 (91) days in 2014 (2015). The abnormal PM2.5 concentrations in June 2014 attributed to agricultural biomass burning from moderate resolution imaging spectroradiometry (MODIS) wildfire maps and aerosol optical depth (AOD) analysis. PM2.5 is recognized as the major pollutant, and a longer interspecies relationship is found between PM2.5 and other criteria pollutants for episode days as compared to non-episode days. The air pollution in Hefei tends to be influenced by local primary emissions, secondary formation, and regional transport from adjacent cities and remote regions. Most areas of Anhui, southern Jiangsu, northern Zhejiang, and western Shandong are identified as the common high-potential source regions of PM2.5. Approximately 9.44 and 8.53 thousand premature mortalities are attributed to PM2.5 exposure in 2014 and 2015. The mortality benefits will be 32% (24%), 47% (41%), 70% (67%), and 85% (83%) of the total premature mortalities in 2014 (2015) when PM2.5 concentrations meet the CAAQS grade II, the World Health Organization (WHO) IT-2, IT-3, and Air Quality Guideline, respectively. Hence, joint pollution prevention and control measures need to be strengthened due to pollutant regional diffusion, and much higher health benefits could be achieved as the Hefei government adopts more stringent WHO guidelines for PM2.5.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S11769-018-0965-3", "year": 2018, "title": "Regional Characteristics and Causes of Haze Events in Northeast China", "abstract": "Northeast China experiences severe atmospheric pollution, with an increasing occurrence of heavy haze episodes. However, the underlying forces driving haze formation during different seasons are poorly understood. In this study, we explored the spatio-temporal characteristics and causes of haze events in Northeast China by combining a range of data sources (i.e., ground monitoring, satellite-based products, and meteorological products). It was found that the Shenyang-Changchun-Harbin (SCH)city belt was the most polluted area in the region on an annual scale. The spatial distribution of air quality index (AQI) values had a clear seasonality, with the worst pollution occurring in winter, an approximately oval-shaped polluted area around western Jilin Province in spring, and the best air quality occurring in summer and most of the autumn. The three periods that typically experienced intense haze events were Period I from mid-October to mid-November (i.e., late autumn and early winter), Period II from late-December to February (i.e., the coldest time in winter), and Period III from April to mid-May (i.e., spring). During Period I, strong PM2.5 emissions from seasonal crop residue burning and coal burning for winter heating were the dominant reasons for the occurrence of extreme haze events (AQI > 300). Period II had frequent heavy haze events (200 < AQI < 300) in the coldest months of January and February, which were due to high PM2.5 emissions from coal burning and vehicle fuel consumption, a lower atmospheric boundary layer, and stagnant atmospheric conditions. Haze events in Period III, with high PM10 concentrations, were primarily caused by the regional transportation of windblown dust from degraded grassland in central Inner Mongolia and bare soil in western Jilin Province. Local agricultural tilling could also release PM10 and enhance the levels of windblown dust from tilled soil. Better control of coal burning, fuel consumption, and crop residue burning in winter and autumn is urgently needed to address the haze problem in Northeast China.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2018.05.014", "year": 2018, "title": "Effect of weakened diurnal evolution of atmospheric boundary layer to air pollution over eastern China associated to aerosol, cloud ABL feedback", "abstract": "Upon the effect of atmospheric stability on air pollution, this study highlights the weakened diurnal evolution of atmospheric boundary layer (ABL), which is crucial to the formation of regional fog-haze and air pollution episodes over eastern China (ECN). The decrease of atmospheric visibility (Vis) during 19732012 is found to be related to the more stable ABL with weakened diurnal evolution that is characterized by a concurrent weakening of surface wind, a decrease in ABL height, and a reduction of diurnal temperature range (DTR, 0.26 and 0.092 C/10-years in the winter and summer, respectively). With a general synchronous variation, the increase in both aerosol loading and cloud cover might work in concert to reduce solar radiation reaching the surface, stabilize ABL and weaken the diurnal ABL evolution, thereby weakening the turbulent mixing of pollutants and enhancing air pollution. This conjecture of aerosol, cloud ABL air pollution feedback, with particular emphasis on the effect of cloud (in addition to the effect of aerosol) on the ABL evolution, is supported by our analysis of 40 years trends in the cloud, Vis and DTR from surface observation, the aerosol optical depth from MODIS, and the validated MERRA-2 reanalysis aerosol, cloud and boundary layer height (by surface observation and routine radiosonde sounding). Regarding the linkage between fog-haze and diurnal evolution of the ABL, the result emphasizes the effect of a persistent high relative humidity (RH), which is found to be important to the formation of regional persistent fog-haze episodes and must be carefully considered in future study. Therefore, a chain of processes is suggested to interpret the occurrence of regional persistent fog-haze episodes over ECN. First, during a polluted day, because of aerosol radiative effects, the high ABL stability and high RH can persist throughout the day, and consequently, favoring the accumulation of pollutants as well as the secondary formation and hygroscopic growth of aerosol. Second, the maintenance of such more stable, humid and polluted ABL is in contrast to a clear day when the ABL is more convective in the afternoon and facilitates the diffusion and dilution of pollutants. Third, under a persistent stable synoptic system, the increase of air pollution associated with the weakened diurnal evolution of ABL due to the aerosol, cloud ABL air pollution feedback, as described above, can be further strengthened, thereby renders more persistent and severe air pollution events. The DTR variation in relationship with the aerosol, cloud, ABL and air pollution is also discussed.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/W12051504", "year": 2020, "title": "Integration of Microwave and Optical/Infrared Derived Datasets from Multi-Satellite Products for Drought Monitoring", "abstract": "Drought is among the most common natural disasters in North China. In order to monitor the drought of the typically arid areas in North China, this study proposes an innovative multi-source remote sensing drought index called the improved TemperatureVegetationSoil Moisture Dryness Index (iTVMDI), which is based on passive microwave remote sensing data from the FengYun (FY)3B-Microwave Radiation Imager (MWRI) and optical and infrared data from the Moderate Resolution Imaging Spectroradiometer (MODIS), and takes the Shandong Province of China as the research area. The iTVMDI integrated the advantages of microwave and optical remote sensing data to improve the original TemperatureVegetationSoil Moisture Dryness Index (TVMDI) model, and was constructed based on the Modified Soil-Adjusted Vegetation Index (MSAVI), land surface temperature (LST), and downscaled soil moisture (SM) as the three-dimensional axes. The global land data assimilation system (GLDAS) SM, meteorological data and surface water were used to evaluate and verify the monitoring results. The results showed that iTVMDI had a higher negative correlation with GLDAS SM (R = 0.73) than TVMDI (R = 0.55). Additionally, the iTVMDI was well correlated with both precipitation and surface water, with mean correlation coefficients (R) of 0.65 and 0.81, respectively. Overall, the accuracy of drought estimation can be significantly improved by using multi-source satellite data to measure the required surface variables, and the iTVMDI is an effective method for monitoring the spatial and temporal variations of drought.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2018EA000426", "year": 2018, "title": "High-Resolution Climate Projections for the Northeastern United States Using Dynamical Downscaling at Convection-Permitting Scales", "abstract": "To paraphrase former Speaker of the House Tip O'Neill, All climate change is localthat is, society reacts most immediately to changes in local weather such as regional heat waves and heavy rainstorms. Such phenomena are not well resolved by the current generation of coupled climate models. Here it is shown that dynamical downscaling of climate reanalyses using a high-resolution regional model can reproduce both the means and extremes of temperature and precipitation as observed in the well-measured northeastern United States. Given this result, the downscaling is applied to climate projections for the middle and end of the 21st century under Representative Concentration Pathway (RCP) 8.5 as well as for the historical time period to help assess regional climate impacts in the northeastern United States. The resulting high-resolution projections are intended to support regional sustainability studies for the northeastern United States and are made publicly available.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.CEJ.2019.04.105", "year": 2019, "title": "Responses of Salmonella typhimurium LT2, Vibrio harveyi, and Cryptosporidium parvum to UVB and UVA radiation", "abstract": "Conventional solar disinfection (SODIS) processes rely on UVA radiation due to exclusion of shorter wavelengths by common SODIS containers. Because of this, these processes are slow and could be improved by inclusion of UVB radiation, which has been reported to be more effective for microbial inactivation than UVA on a photon basis, but is typically present at lower spectral irradiance. To examine the potential for microbial inactivation resulting from exposure to solar UVB radiation at sea-level, experiments were conducted to define the UVB/UVA action and effectiveness spectra for Salmonella typhimurium LT2, Vibrio harveyi, and Cryptosporidium parvum, which are representative of three of the most prevalent waterborne pathogens globally. For each organism, the action spectrum was similar in shape to its corresponding DNA absorption spectrum, thereby suggesting that inactivation of these organisms by UVB irradiation was largely attributable to DNA damage. Modeling and measurements of ambient solar UVB spectral irradiance were compared, indicating a trend of model over-prediction of spectral irradiance by up to 20% on cloudless days. Effectiveness spectra for organism/location pairs were calculated as the product of the action spectra and calculated spectral irradiance to identify the most effective wavelengths for inactivation. For the organisms studied, maximum predicted effectiveness appeared at wavelengths between 318 and 330 nm. At 320 nm, the simulated inactivation of C. parvum in the top 20-cm of an outdoor swimming pool (mid-latitude location in summer) after one hour of exposure was approximately 6-log10 units. These results suggest that solar UVB irradiation could yield substantial inactivation of C. parvum in outdoor recreational waters, where these protozoan parasites are responsible for a large fraction of the disease burden among swimmers.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.APR.2020.04.016", "year": 2020, "title": "Meteorology of air pollution in Los Angeles", "abstract": "The meteorology of air pollution in Los Angeles (LA) is studied via daily near-surface air chemistry, aerosol and weather data assimilated from insitu and satellite measurements in the period 20052016. Atmospheric fields are regressed onto seasonal air pollution indices and reveal that a ridge of high pressure north of California weakens the longshore circulation and reduces dispersion. A 10-case composite of atmospheric anomalies during winter air pollution episodes was analyzed. Periods of high nitrogen dioxide and carbon monoxide show increasing temperature gradients that induce the converging of land-seabreezes beneath a strengthened thermal inversion. The atmospheric environment of an air pollution episode in December 2005 reveals recirculating trajectories. Efforts to limit emissions have contributed to reductions of nitrogen dioxide, but other constituents remain a public health concern. Knowledge of weather conditions underlying air pollution episodes will improve warnings and the effectiveness of mitigating actions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1111/JBI.12913", "year": 2017, "title": "Biogeography and molecular diversity of coral symbionts in the genus Symbiodinium around the Arabian Peninsula", "abstract": "Aim Coral reefs rely on the symbiosis between scleractinian corals and intracellular, photosynthetic dinoflagellates of the genus Symbiodinium making the assessment of symbiont diversity critical to our understanding of ecological resilience of these ecosystems. This study characterizes Symbiodinium diversity around the Arabian Peninsula, which contains some of the most thermally diverse and understudied reefs on Earth. Location Shallow water coral reefs throughout the Red Sea (RS), Sea of Oman (SO), and Persian/Arabian Gulf (PAG). Methods Next-generation sequencing of the ITS2 marker gene was used to assess Symbiodinium community composition and diversity comprising 892 samples from 46 hard and soft coral genera. Results Corals were associated with a large diversity of Symbiodinium, which usually consisted of one or two prevalent symbiont types and many types at low abundance. Symbiodinium communities were strongly structured according to geographical region and to a lesser extent by coral host identity. Overall symbiont communities were composed primarily of species from clade A and C in the RS, clade A, C, and D in the SO, and clade C and D in the PAG, representing a gradual shift from C- to D-dominated coral hosts. The analysis of symbiont diversity in an Operational Taxonomic Unit (OTU)-based framework allowed the identification of differences in symbiont taxon richness over geographical regions and host genera. Main conclusions Our study represents a comprehensive overview over biogeography and molecular diversity of Symbiodinium in the Arabian Seas, where coral reefs thrive in one of the most extreme environmental settings on the planet. As such our data will serve as a baseline for further exploration into the effects of environmental change on hostsymbiont pairings and the identification and ecological significance of Symbiodinium types from regions already experiencing Future Ocean conditions.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/JOC.6476", "year": 2020, "title": "Diurnal summer climate of the Abyssinia highlands", "abstract": "This study explores the structure and modulation of diurnal climate over the Abyssinia highlands 715N, 3540E using hourly satellite and reanalysis data in JuneAugust season for the years 20142016. Solar heating generates surface heat fluxes that trigger moisture convergence in the late afternoon. Satellite measured rainfall frequently propagates westward from the highest mountains near 14N, 38E at 7 m s1 from 1200 to 1800 UTC (3 to 9 p.m. local time). The mean diurnal cycle of reanalysis and satellite (GPM) hourly rainfall are in-phase and exhibit min/max at 0900/1600 UTC. Diagnostic analysis reveals a 3-hr delay from surface evaporation to mid-tropospheric moisture uplift, and another 3-hr delay to low-level velocity potential maxima, which together modulate the diurnal rainfall. Morning cooling and convective inhibition over the highlands is just as strong as evening enhancement. Year-to-year variations in the amplitude of diurnal rainfall are small and suggest dependable water resources.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ATMOSRES.2017.07.012", "year": 2017, "title": "Statistical intercomparison and validation of multisensory aerosol optical depth retrievals over three AERONET sites in Kenya, East Africa", "abstract": "Over the last two decades, a number of space-borne sensors have been used to retrieve aerosol optical depth (AOD). The reliability of these datasets over East Africa (EA), however, is an important issue in the interpretation of regional aerosol variability. This study provides an intercomparison and validation of AOD retrievals from the MODIS-Terra (DT and DB), MISR and OMI sensors against ground-based measurements from the AERONET over three sites (CRPSM_Malindi, Nairobi, and ICIPE_Mbita) in Kenya, EA during the periods 20082013, 20052009 and 20062015, respectively. The analysis revealed that MISR performed better over the three sites with about 82.5% of paired AOD data falling within the error envelope (EE). MODIS-DT showed good agreement against AERONET with 59.05% of paired AOD falling within the sensor EE over terrestrial surfaces with relatively high vegetation cover. The comparison between MODIS-DB and AERONET revealed an overall lower performance with lower Gfraction (48.93%) and lower correlation r = 0.58; while AOD retrieved from OMI showed less correspondence with AERONET data with lower Gfraction (68.89%) and lowest correlation r = 0.31. The monthly evaluation of AODs retrieved from the sensors against AERONET AOD indicates that MODIS-DT has the best performance over the three sites with highest correlation (0.710.84), lowest RMSE and spread closer to the AERONET. Regarding seasonal analysis, MISR performed well during most seasons over Nairobi and Mbita; while MODIS-DT performed better than all other sensors during most seasons over Malindi. Furthermore, the best seasonal performance of most sensors relative to AERONET data occurred during JuneAugust (JJA) attributed to modulations induced by a precipitation-vegetation factor to AOD satellite retrieval algorithms. The study revealed the strength and weakness of each of the retrieval algorithm and forms the basis for further research on the validation of satellite retrieved aerosol products over EA.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.135016", "year": 2020, "title": "Land susceptibility to water and wind erosion risks in the East Africa region", "abstract": "Land degradation by water and wind erosion is a serious problem worldwide. Despite the significant amount of research on this topic, quantifying these processes at large- or regional-scale remains difficult. Furthermore, very few studies provide integrated assessments of land susceptibility to both water and wind erosion. Therefore, this study investigated the spatial patterns of water and wind erosion risks, first separately and then combined, in the drought-prone region of East Africa using the best available datasets. As to water erosion, we adopted the spatially distributed version of the Revised Universal Soil Loss Equation and compared our estimates with plot-scale measurements and watershed sediment yield (SY) data. The order of magnitude of our soil loss estimates by water erosion is within the range of measured plot-scale data. Moreover, despite the fact that SY integrates different soil erosion and sediment deposition processes within watersheds, we observed a strong correlation of SY with our estimated soil loss rates (r2 = 0.4). For wind erosion, we developed a wind erosion index by integrating five relevant factors using fuzzy logic technique. We compared this index with estimates of the frequency of dust storms, derived from long-term Sea-Viewing Wide Field-of-View Sensor Level-3 daily data. This comparison revealed an overall accuracy of 70%. According to our estimates, mean annual gross soil loss by water erosion amounts to 4 billion t, with a mean soil loss rate of 6.3 t ha1 yr1, of which ca. 50% was found to originate in Ethiopia. In terms of land cover, ca. 50% of the soil loss by water erosion originates from cropland (with a mean soil loss rate of 18.4 t ha1 yr1), which covers ca. 15% of the total area in the study region. Model results showed that nearly 10% of the East Africa region is subject to moderate or elevated water erosion risks (>10 t ha1 yr1). With respect to wind erosion, we estimated that around 25% of the study area is experiencing moderate or elevated wind erosion risks (equivalent to a frequency of dust storms >45 days yr1), of which Sudan and Somalia (which are dominated by bare/sparse vegetation cover) have the largest share (ca. 90%). In total, an estimated 8 million ha is exposed to moderate or elevated risks of soil erosion by both water and wind. The results of this study provide new insights on the spatial patterns of water and wind erosion risks in East Africa and can be used to prioritize areas where further investigations are needed and where remedial actions should be implemented.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1134/S0001433818090177", "year": 2018, "title": "Large-Scale Smoke Haze over the European Part of Russia and Belorus in July 2016", "abstract": "The smoke haze over the European part of Russia (EPR) and Belorus in July 2016 has been studied with the use of aerosol optical thickness (AOT) data measured by MODIS satellite spectrometers. The AOT maximum on the territory limited by coordinates 4570 N and 2060 E reached 2.95 on July 24, 2016 with an average regional value of 0.48. The total mass of smoke aerosol without the area covered by clouds was 0.73 million tons. Analysis of the wind fields and five-day back trajectories of air mass movement showed that the smoke was transported by the northeast winds to the EPR and Belorus from western Siberia, including the Yamalo-Nenets Autonomous District, which was characterized by large forest fires from July 17 to 23. Simulation of the radiation regime of the smoky atmosphere indicated that the average radiative forcings of smoke aerosol at upper and lower boundaries of the atmosphere for the above-mentioned territory are 29 and 54 W/m2, respectively (the extreme values are 124 and 154 W/m2, respectively). A comparative analysis of the smoke haze characteristics over the EPR in July 2016 and in summer 2010 has been conducted. According to ground-based measurement data, the mass concentration of PM10 during the smoke period from July 24 to 27 in the Moscow region reached 0.25 mg/m3.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1016/J.MARCHEM.2020.103850", "year": 2020, "title": "Bajacalifornian dust deposition and atmospheric input of iron to the Gulf of California during the summer", "abstract": "Iron (Fe) is an essential micronutrient for all living organisms and its atmospheric supply to the surface waters of marginal seas remains poorly understood. Here we report the seasonal and spatial variability of atmospheric mineral dust deposition and Fe fluxes along the west coast of the Gulf of California (GC). Meteorological data and dust samples were collected from June 2010 to October 2013 at three sites of the eastern side of Baja California Peninsula (BCP). Evidence of an across-BCP wind component (W-E) during the warm season (MaySeptember) was found, suggesting that winds crossing the BCP from west to east were an important source of variability. Coincidently, dust deposition at the northern and center sites were significantly (p ", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.15517/RBT.V65I1-1.31687", "year": 2017, "title": "Reproductive cycle of the sea cucumber (Isostichopus fuscus) and its relationship with oceanographic variables at its northernmost distribution site", "abstract": "The brown sea cucumber Isostichopus fuscus is highly prized and intensively fished, yet no studies of its reproductive cycle at its northernmost distribution site exist. To characterize its reproductive cycle, monthly surveys (Oct 2014-Dec 2016) that included gonad collection were conducted in 118 sites along the eastern coast of Baja California, including islands from Bahia San Luis Gonzaga (29o 49 14.18 N, 114 o 356.17 W) to the 28th parallel north. A total of 2 808 sea cucumber specimens were measured (mean length SD = 21.4 6 cm) and weighed (375.6 249 g). Seven hundred and seventeen organisms were dissected but only 553 gonads were suitable for processing through histological analysis to identify sex and developmental stage. Of these individuals, 224 were female, 162 were male, 157 were undifferentiated and 10 were hermaphrodites, resulting in a sex ratio that was significantly different from 1:1 (2 = 36.63, P = 0.03, df = 23). There was no statistical difference (p > 0.05) of either size or weight between males and females, but females were larger than males. The length-weight relationship observed was W = 0.18L2.4, r2 = 0.82, p <0.05 while the size-at-first-maturity was 16 cm. Five gonad stages were identified: 28% undifferentiated, 9% gametogenesis, 15% mature, 19% expulsion and 29% post-expulsion. The Oocyte Theoretical Diameter (OTD) was estimated by measuring the area of 10 291 oocytes, finding 2 307 individuals in oogenesis (mean SD of 65.3 19.7 m), 3 630 in maturity (66.0 17.8 m), 3 756 in spawning (73.8 14.6 m) and 868 in post-spawning (49.18 20.7 m). Modal progression analysis shows that oocytes increase 23% in size from oogenesis to maturity, and decrease 9%in size from maturity to spawning and, on average, oocytes are 72% smaller post-spawning that during spawning. Rev. Biol. Trop. 65(Suppl. 1): S180-S196. Epub 2017 November 01.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSRES.2017.09.019", "year": 2018, "title": "Impact of SST on heavy rainfall events on eastern Adriatic during SOP1 of HyMeX", "abstract": "The season of late summer and autumn is favourable for intensive precipitation events (IPE) in the central\nMediterranean. During that period the sea surface is warm and contributes to warming and moistening of the\nlowest portion of the atmosphere, particularly the planetary boundary layer (PBL). Adriatic sea is surrounded by\nmountains and the area often receives substantial amounts of precipitation in short time (24 h). The IPEs are a\nconsequence of convection triggered by topography acting on the southerly flow that has brought the unstable\nair to the coastline. Improvement in prediction of high impact weather events is one of the goals of The\nHydrological cycle in the Mediterranean eXperiment (HyMeX). This study examines how precipitation patterns\nchange in response to different SST forcing. We focus on the IPEs that occurred on the eastern Adriatic coast\nduring the first HyMeX Special observing period (SOP1, 6 September to 5 November 2012). The operational\nforecast model ALADIN uses the same SST as the global meteorological model (ARPEGE from Meteo France), as\nwell as the forecast lateral boundary conditions (LBCs). First we assess the SST used by the operational atmo-\nspheric model ALADIN and compare it to the in situ measurements, ROMS ocean model, OSTIA and MUR\nanalyses. Results of this assessment show that SST in the eastern Adriatic was overestimated by up to 10 K during\nHyMeX SOP1 period. Then we examine the sensitivity of 8 km and 2 km resolution forecasts of IPEs to the\nchanges in the SST during whole SOP1 with special attention to the intensive precipitation event in Rijeka.\nForecast runs in both resolutions are performed for the whole SOP1 using different SST fields prescribed at initial\ntime and kept constant during the model forecast. Categorical verification of 24 h accumulated precipitation did\nnot show substantial improvement in verification scores when more realistic SST was used. Furthermore, the\nresults show that the impact of introducing improved SST in the analysis on the precipitation forecast varies for\ndifferent cases. There is generally a larger sensitivity to the SST in high resolution than in the lower one, al-\nthough the forecast period of the latter is longer.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S12647-019-00314-Y", "year": 2019, "title": "Total Column Ozone, Precipitable Water Content and Aerosol Optical Thickness Over Atigre Village, a Tropical Station: First Observations", "abstract": "In this paper, we report first-time observations of total column ozone (TCO), aerosol optical thickness (AOT) and precipitable water content (PWC) at five different wavelengths using compact, handheld, multichannel sun photometer (Microtops II ozonometer) at Atigre village (16.74N latitude, 74.37E longitude, 604 ms altitude above sea level). The three optical filters at wavelengths 305 nm, 312 nm and 320 nm are used to detect the TCO, while two optical filters 936 nm and 1020 nm are used to detect the PWC and AOT, respectively. We have been collecting data from September 1, 2017, and 122 days are selected from September 1, 2017, to December 31, 2017, to present as first observations of TCO, AOD and PWC. The mean values of TCO, AOT and PWC are found to be 261.2 ( 9.22) DU, 0.25 ( 0.04) and 1.98 ( 0.79) cm, respectively, during this period. The TCO measurements taken by the Microtops II ozonometer are compared with the ozone monitoring instrument satellite data over Atigre. We found that PWC and AOT values are negatively correlated ( 0.54) during monsoon season, while they show positive correlation (0.63) during other seasons with 90% significance level. The diurnal variation of TCO, PWC and AOT differ in monsoon and the post-monsoon season.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.MARENVRES.2019.05.008", "year": 2019, "title": "Lower diversity of recruits in coastal reef assemblages are associated with higher sea temperatures in the tropical South Atlantic", "abstract": "Climate change will lead to community shifts and increase the vulnerability of coastal marine ecosystems, but there is yet insufficient detail of how early life stages of marine populations are linked to oceanic-climate dynamics. This study aimed to investigate how ocean-climate variability is associated with spatial and temporal changes in benthic larval recruitment of tropical reef assemblages. Recruitment (abundance, richness, and diversity) of benthic invertebrates was monitored for one year on macroalgal beds in four rocky reefs in a marine protected region in the Eastern coast of Brazil, and compared to fluctuations in meteo-oceanographic conditions at multiple temporal scales (days, weeks, and months). Our results revealed that recruitment of benthic invertebrates varies widely (up to 15 orders of magnitude) among sampled reefs and in time, with wave height, wind speed, and sea temperature being significantly related to recruitment variability. We detected strong taxonomic variability in recruitment success and ocean-climate variables, which highlights the complexity of estimating community vulnerability to climate change in benthic communities. Given that macroalgal beds are key to recruitment of some species regionally (430 km), the protection of coastal nursery habitats may be critical for marine conservation and species adaptation in a climate change scenario. Considering the projected ocean-climate change in IPCC scenarios, our study suggests that recruitment of marine populations in coastal reefs could be highly sensitive to climate change in the tropical South Atlantic Ocean.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSASE.2018.03.010", "year": 2018, "title": "Investigating the effects of episodic Super-cyclone 1999 and Phailin 2013 on hydro-meteorological parameters and agriculture: An application of remote sensing", "abstract": "The tropical cyclones (TCs) are often associated with unprecedented heavy rainfall, and have a pronounced impact over East coast states of India. This study has done comprehensive investigation on contribution of two episodic TCs rainfall to the annual rainfall using satellite based rainfall estimates from TMPA-3B42 (daily product), and rainfall data from India Meteorological Department (IMD) observations. We analyzed both rainfall distribution and inundation extent induced by two episodic severe cyclonic events (Supercyclone 1999 and Phailin 2013), and assessed their impacts on hydro-meteorological parameters and agricultural productivity. Our findings suggest that rainfall originated from two episodic TCs significantly contributed to the annual rainfall, accounting for about 525% over the coastal districts of Odisha state. Howbeit, it was subjected to underestimation owing to rainfall biases of TMPA-3B42 during TCs, which was evident when it was compared with IMD measurements. Along the TCs track, intense rainfall followed by peak discharge from the river basins caused substantial flooding and inundation of croplands over the coastal regions. The TC related rainfall, strong winds, and storm surges have diminished kharif season's agricultural production, as crops were submerged during these periods. Overall, the rice production has been diminished by 57%, and this rice production even lowered by more than 70% in some of the districts. Most severely affected districts (Ganjam, Puri, Cuttack, Jajpur, Bhadrak, Baleshwar) were located close to landfall, where croplands are dominating land use type. These results inferred that the isolated severe TCs could bring significant amount of rainfall, which would cause widespread impacts on agricultural activities. Finally, the findings of this unique study recommends that the satellite based rainfall estimate data can act as a valuable input for flood modeling and crop monitoring at different scales to alleviate hydrometeorological and agricultural impacts.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 0, "name": "Agriculture" }, { "id": 9, "name": "Floods" } ] }, { "doi": "10.1002/ASL.975", "year": 2020, "title": "Recent trend in the global distribution of aerosol direct radiative forcing from satellite measurements", "abstract": "Global distribution of aerosol direct radiative forcing (DRF) is estimated using Clouds and Earth's Radiant Energy System (CERES) synoptic (SYN) 1 datasets. During 20012017, a statistically significant change of global DRFs is revealed with a general decreasing trend (i.e., a reduced cooling effect) at the top of the atmosphere (DRFTOA 0.017 Wm2year1) and at the surface (DRFSFC 0.033 Wm2year1) with rapid change over the land compared to the global ocean. South Asia and Africa/Middle East regions depict significant increasing trend of atmospheric warming by 0.025 and 0.002 Wm2year1 whereas, the rest of the regions show a decline. These regional variations significantly modulate the global mean DRF (5.36 0.04 Wm2 at the TOA and 9.64 0.07 Wm2 at the surface during the study period). The observed DRF trends are coincident with the change in the underlying aerosol properties, for example, aerosol optical depth, Angstrom exponent and partly due to the increasing columnar burden of SO2 over some of the regions. This indicates that increasing industrialization and urbanization have caused prominent change in the DRF during recent decades.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1111/JFR3.12647", "year": 2020, "title": "Enhanced flood mapping using synthetic aperture radar (SAR) images, hydraulic modelling, and social media: A case study of Hurricane Harvey (Houston, TX)", "abstract": "Post event flooding maps are currently extracted from synthetic-aperture radar (SAR) and/or optical satellite images or developing using hydraulic model simulations. Several sources of uncertainties impact the accuracy of such flood maps constructed from each method, especially in urban areas. An integrated approach that combines satellite imagines of flooded areas, hydraulic models, and markers from social media that should reduce these uncertainties and allow a more accurate reconstruction of flooded urban areas, is presented in this paper. The flooding associated with Hurricane Harvey in Houston, TX was chosen as a case study. Model validations demonstrate the effectiveness of our integrated approach in reconstructing an accurate flooding map, as well as the temporal and spatial patterns of flooding. Using the experience from this case study we discuss the possibility to use satellite data, instead of ground-based rainfall gauge measurements as precipitation inputs to the hydraulic model; and possible error sources in simulating flooding in urban areas using the hydraulic model.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.POLAR.2020.100525", "year": 2020, "title": "Correlations among phytoplankton biomass, sea ice and wind speed in Barents Sea and the future climate trends", "abstract": "Global climate closely links with the Arctic Ocean ecosystem especially in the Barents Sea. The distributions and correlations among chlorophyll-a (CHL), sea ice concentration (ICE), wind speed (WIND), sea surface temperature (SST) and mixed layer depth (MLD) are studied within the region of Barents Sea (70N-80N, 30E40E) over the period 20032013. CHL increased from north to south in general. Ice melted rapidly in the southern region (70N-75N) and had less impact than SST on phytoplankton blooming. Melting ice in northern region (75N-80N) contributed significant source on phytoplankton development. WIND had negative correlations with CHL in spring blooming season and had positive correlations during autumn. Dimethylsulfide (DMS) concentration and sea-to-air DMS flux are simulated using a comprehensive biogeochemical model. The key model parameters are calibrated using a genetic algorithm under contemporary climate conditions. Environmental factors and DMS sea-air flux are compared for 1CO2 and 4CO2 climate conditions. By 4CO2, SST increases more than doubles, DMS increases 27.5%. Mean annual DMS sea-to-air flux increases 323%. The increase of DMS flux under 4CO2 conditions indicates that Arctic climate may be counteracting with the warming by 4CO2.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/ATMOS11090901", "year": 2020, "title": "Spatial-Temporal Assessment of Satellite-Based Rainfall Estimates in Different Precipitation Regimes in Water-Scarce and Data-Sparse Regions", "abstract": "Accurate precipitation measurement is very important for socio-hydrological resilience in the face of frequent extreme weather events such as cyclones. This study evaluates the performance of two satellite products: the Tropical Rainfall Measuring Mission (TRMM 3B43V7) Multi-satellite Precipitation Analysis (TMPA, hereafter: TRMM) and the Integrated Multi-satellite Retrievals for GPM (IMERG, Final Run V06, hereafter: GPM) in the Sultanate of Oman. Oman is an arid country that generally has few rainy days, but has experienced significant flash floods, tropical storms and cyclones recently, leading to the loss of lives and millions of dollars in damage. Accurate precipitation analysis is crucial in flood monitoring, hydrologic modeling, and the estimation of the water balance of any basin, and the lack of a sufficient weather monitoring network is a barrier to accurate precipitation measurement. Satellite rainfall estimates can be a reliable option in sparse network areas, especially in arid and semi-arid countries. This study evaluated monthly rainfall (hereafter: OBSERVED) levels at 77 meteorological stations from January 2016 to December 2018. The capacity of the TRMM and GPM satellite products to detect monthly rainfall amounts at varying precipitation thresholds was also evaluated. Findings included (1) overall and across the 11 Governorates of Oman, both satellite products show different spatial variability and performance to the OBSERVED at the monthly, seasonal, and annual temporal scales; (2) from the perspective of precipitation detection and frequency bias, GPM showed a similar performance to TRMM at detecting low precipitation (2 mm/month) but was poorer at detecting high precipitation (>30 mm/month) across the entire country as well as in the Northern, Interior, and Dhofar regions; (3) both products show similarities to the OBSERVED through the partitioning of their seasonal time series into a distinct number of homogenous segments; and (4) both products had difficulty reproducing OBSERVED levels in the Dhofar and Interior regions, which is consistent with studies conducted in mountainous and coastal regions. With the aim of reproducing the spatial and temporal structure of OBSERVED in a rugged terrain, the study shows that both satellite products can be used in areas of sparse rain gauges or as additional observation for studies of extreme weather events. Overall, this study suggests that for Oman, both satellite products can be used as proxies for OBSERVED with appropriate bias corrections and GPM is also a reliable replacement for TRMM as a precipitation satellite product. The findings will be useful to the countrys flood resilience and mitigation efforts, especially in areas where there is sparse rain gauge coverage.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/HESS-24-3899-2020", "year": 2020, "title": "Revisiting the global hydrological cycle: is it intensifying?", "abstract": "Abstract. As a result of technological advances in monitoring atmosphere, hydrosphere, cryosphere and biosphere, as well as in data management and processing, several databases have become freely available. These can be exploited in revisiting the global hydrological cycle with the aim, on the one hand, to better quantify it and, on the other hand, to test the established climatological hypotheses according to which the hydrological cycle should be intensifying because of global warming. By processing the information from gridded ground observations, satellite data and reanalyses, it turns out that the established hypotheses are not confirmed. Instead of monotonic trends, there appear fluctuations from intensification to deintensification, and vice versa, with deintensification prevailing in the 21st century. The water balance on land and in the sea appears to be lower than the standard figures of literature, but with greater variability on climatic timescales, which is in accordance with HurstKolmogorov stochastic dynamics. The most obvious anthropogenic signal in the hydrological cycle appears to be the over-exploitation of groundwater, which has a visible effect on the rise in sea level. Melting of glaciers has an equal effect, but in this case it is not known which part is anthropogenic, as studies on polar regions attribute mass loss mostly to ice dynamics.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1016/J.ENVINT.2020.106042", "year": 2020, "title": "Neighborhood greenness associated with chronic obstructive pulmonary disease: A nationwide cross-sectional study in China", "abstract": "Differential findings have been reported on the association between neighborhood greenness and chronic obstructive pulmonary disease (COPD). The underlying reasons might be the different types of vegetation and the diagnosis methods used in different studies. In this nationwide cross-sectional study in China, we examined the linkage between neighborhood greenness and COPD prevalence among 66,752 adults aged 40 years and above. Neighborhood greenness was estimated using the normalized difference vegetation index (NDVI) based on satellite imagery within buffers of 100, 300, 500, 1000, 2000, 3000 and 5000 m of residential community of the participants. COPD was defined according to the 2017 Global Initiative for Chronic Obstructive Lung Disease lung function criteria. A two-level logistic regression model was applied to estimate the associations. Finally, 9134 adults were classified as COPD. We observed significant positive associations between neighborhood greenness and COPD prevalence. The odds ratio for each interquartile range increase in NDVI within 100 m buffer was 1.08 (95% CI: 1.01, 1.15) after adjustment for potential confounders. Consistent associations were observed across all other NDVI buffer sizes. Stratified analyses revealed that younger adults (4065 years) and urban residents might be the vulnerable subpopulations. Further regional analyses found that residents from the Northeastern and Northern China were more likely to have this association. Our results indicated that neighborhood greenness might be one risk factor of COPD prevalence. Our study have important public health implications for allocating the surrounding green spaces among living areas, especially for those with respiratory illness; however, the findings and the underlying mechanisms warrant further examinations in longitudinal settings.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3389/FPHYS.2020.00637", "year": 2020, "title": "Increased Diurnal Activity Is Indicative of Energy Deficit in a Nocturnal Mammal, the Aardvark", "abstract": "Shifting activity to cooler times of day buffers animals from increased heat and aridity under climate change. Conversely, when resources are limited, some nocturnal species become more diurnal, reducing energetic costs of keeping warm at night. Aardvarks (Orycteropus afer) are nocturnal, obligate ant- and termite-eating mammals which may be threatened directly by increasing heat and aridity, or indirectly by the effects of climate change on their prey. We hypothesised that the minimum 24-h body temperature of aardvarks would decline during energy scarcity, and that aardvarks would extend their active phases to compensate for reduced resource availability, possibly resulting in increased diurnal activity when aardvarks were energetically compromised. To measure their thermoregulatory patterns and foraging activity, we implanted abdominal temperature and activity data loggers into twelve adult aardvarks and observed them for varying durations over three years in the Kalahari. Under non-drought conditions, aardvarks tightly controlled their 24-h body temperature rhythm (mean amplitude of the 24-h body temperature rhythm was 1.8 0.3 C during summer and 2.1 0.1 C during winter) and usually were nocturnal. During a summer drought, aardvarks relaxed the precision of body temperature regulation (mean 24-h amplitude 2.3 0.4 C) and those that subsequently died shifted their activity to progressively earlier times of day in the weeks before their deaths. Throughout the subsequent winter, the aardvarks minimum 24-h body temperatures declined, causing exaggerated heterothermy (4.7 1.3 C; absolute range 24.7 to 38.8 C), with one individuals body temperature varying by 11.7 C within 8 h. When body temperatures were low, aardvarks often emerged from burrows during daytime, and occasionally returned before sunset, resulting in completely diurnal activity. Aardvarks also shortened their active periods by 25 % during food scarcity, likely to avoid energetic costs incurred by foraging. Despite their physiological and behavioural flexibility, aardvarks were unable to compensate for reduced food availability. Seven study aardvarks and several others died, presumably from starvation. Our results do not bode well for aardvarks facing climate change, and for the many animal species dependent on aardvark burrows for refuge.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.DYNATMOCE.2020.101157", "year": 2020, "title": "The effect of wind and temperature to phytoplankton biomass during blooming season in Barents Sea", "abstract": "The Barents Sea is the most productive sea in the Arctic. The main causes of phytoplankton spring blooms are studied for a decadal time period of 20032013 at the region of (70 N-80 N, 30 E-40 E) in Barents Sea. Due to the rapidly ice melt in the southern region (70 N-75 N), almost no ice left after year 2005, sea surface temperature (SST) and wind speed (WIND) are two main dominant factors influencing phytoplankton blooming in the southern region. Ice melt is another important factor of phytoplankton blooming in the northern region (75 N80 N). SST and CHL had positive correlations during blooming season but negative correlations during summer time. The lower SST in spring could result in earlier blooming in the region. Higher SST and higher WIND could result in later blooming. Positive NAO after April 2013 caused higher SST in 2013. Increasing WIND would cause CHL reduced accordingly. Blooming period is from late April to late May in the southern region, and 12 weeks later in the northern region. During blooming season, SST was less than 4 C and WIND was less than 10 m/s. The higher winds (over 15 m/s) in early spring would brought more nutrients from bottom to surface and cause higher blooming (near 10 mg/m3 in year 2010) after WIND is reduced to 58 m/s. Higher WIND (around 10 m/s) could generate longer blooming period (more than a week) during late May in the southern region. Decrease of WIND and increase of melting ice, with slightly increase of SST and decrease of mixed layer depth (MLD), are all the factors of phytoplankton blooming in late spring and early summer.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/BG-17-3815-2020", "year": 2020, "title": "The Southern Annular Mode (SAM) influences phytoplankton communities in the seasonal ice zone of the Southern Ocean", "abstract": "Abstract. Ozone depletion and climate change are causing the Southern Annular Mode (SAM) to become increasingly positive, driving stronger winds southward in the Southern Ocean (SO), with likely effects on phytoplankton habitat due to possible changes in ocean mixing, nutrient upwelling, and sea ice characteristics. This study examined the effect of the SAM and 12 other environmental variables on the abundance of siliceous and calcareous phytoplankton in the seasonal ice zone (SIZ) of the SO. A total of 52 surface-water samples were collected during repeat resupply voyages between Hobart, Australia, and Dumont d'Urville, Antarctica, centred around longitude 142 E, over 11 consecutive austral springsummer seasons (20022012), and spanning 131 d in the springsummer from 20 October to 28 February. A total of 22 taxa groups, comprised of individual species, groups of species, genera, or higher taxonomic groups, were analysed using CAP analysis (constrained analysis of principal coordinates), cluster analysis, and correlation. Overall, satellite-derived estimates of total chlorophyll and measured depletion of macronutrients both indicated a more positive SAM was associated with greater productivity in the SIZ. The greatest effect of the SAM on phytoplankton communities was the average value of the SAM across 57 d in the previous austral autumn centred around 11 March, which explained 13.3 % of the variance in community composition in the following springsummer. This autumn SAM index was significantly correlated pair-wise (p<0.05) with the relative abundance of 12 of the 22 taxa groups resolved. A more positive SAM favoured increases in the relative abundance of large Chaetoceros spp. that predominated later in the springsummer and reductions in small diatom taxa and siliceous and calcareous flagellates that predominated earlier in the springsummer. Individual species belonging to the abundant Fragilariopsis genera responded differently to the SAM, indicating the importance of species-level observation in detecting SAM-induced changes in phytoplankton communities. The day through the springsummer on which a sample was collected explained a significant and larger proportion (15.4 %) of the variance in the phytoplankton community composition than the SAM, yet this covariate was a proxy for such environmental factors as ice cover and sea surface temperature, factors that are regarded as drivers of the extreme seasonal variability in phytoplankton communities in Antarctic waters. The impacts of SAM on phytoplankton, which are the pasture of the SO and principal energy source for Antarctic life, would have ramifications for both carbon export and food availability for higher trophic levels in the SIZ of the SO.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41598-020-69344-W", "year": 2020, "title": "SO2 and HCHO over the major cities of Kazakhstan from 2005 to 2016: influence of political, economic and industrial changes", "abstract": "Satellite observations of the Ozone Monitoring Instrument (OMI) for tropospheric sulfur dioxide (SO2) and formaldehyde (HCHO) column mass densities (CMD) are analyzed for the period 20052016 over the atmosphere of Kazakhstan. Regarding SO2 the major hot spots relate to regions with high population and large industrial facilities. Such an example is the city of Ekibastuz that hosts the biggest thermal power plants in the country and exhibits the higher SO2 CMD at national level. The annual average CMD in Ekibastuz reaches 2.5 105 kg/m2, whereas for the rest of the country respective values are 6 times lower. Other hotspots, mostly urban conglomerates such as Almaty and Nur-Sultan, experience high CMDs of SO2 in particular years, such as 2008. One of the main reasons for this behavior is the financial crisis of 2008, forcing the application of alternate heating sources based on cheap low-quality coal. Regarding HCHO, an oxygenated Volatile Organic Compound (VOC), the main hot spot is noticed over the city Atyrau, the oil capital of the country where two massive oil fields are located. The highest HCHO CMD (9 1015 molecules/cm2) appears in the summertime due to secondary production as a result of the photo-oxidation of VOCs emitted by industrial sectors, oil refinery plants and vehicles. Strongly elevated HCHO amounts are also observed in Nur-Sultan in 2012 that could be due to the residential coal combustion and vehicle exhaust under poor winter dispersion conditions. Significant reductions in HCHO observed between 2012 and 2015 can be attributed to two significant measures implemented in the country in 2013 that aimed at the improvement of air quality: the introduction of the emission trading system (ETS) for greenhouse gases and Euro-4 standards for new vehicles entering the national vehicle fleet.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/AMT-2020-101", "year": 2020, "title": "Methane vertical profiles over the Indian subcontinent derived from the GOSAT/TANSO-FTS thermal infrared sensor", "abstract": "Abstract. We examined CH4 variability over different regions of India and the surrounding oceanic regions derived from thermal infrared (TIR) band observations by the Thermal And Near-infrared Sensor for carbon Observation-Fourier Transform Spectrometer (TANSO-FTS) onboard the Greenhouse gases Observation SATellite (GOSAT) and simulated by the updated MIROC4.0-based Atmospheric Chemistry Tracer Model (MIROC4-ACTM) for the period 20092014. This study attempts to understand the sensitivity of the vertical profile retrievals at different layers of the troposphere and lower stratosphere, arising from the averaging kernels and a priori assumptions. We stress that this is of particular importance when the satellite derived products are analyzed using a different ACTMs from that is used as retrieval a priori. A comparison of modeled and retrieved CH4 vertical profiles shows the 22 vertical levels of GOSAT/TANSO-FTS TIR retrievals provide critical information about transport from the top of the boundary layer to the upper troposphere and lower stratosphere in a consistent manner. The mean model-GOSAT TIR CH4 mismatch is within 50 ppb, excepting 150 hPa and upward, where the sensitivity of GOSAT/TANSO-FTS TIR observations becomes very low. Convolution of the modeled profiles with GOSAT/TANSO-FTS TIR averaging kernels reduce the mismatch to below uncertainty. Distinct seasonal variations of CH4 have been observed at the upper atmospheric boundary layer (800 hPa), free troposphere (500 hPa), and upper troposphere (200 hPa) levels over northern and southern regions of India corresponding to the southwesterly monsoon (JulySeptember) and post-monsoon (OctoberDecember) seasons. Analysis of the transport and emission contributions to CH4 suggests that the CH4 seasonal cycle over the Indian subcontinent is governed by both the heterogeneous distributions of surface emissions and the influence of the global monsoon divergent wind circulations. GOSAT/TANSO-FTS TIR observations provide additional information about CH4 observations in this region compared to what is known from in situ data, which is important for improving the accuracy of emission flux optimization. Based on two emission sensitivity simulations, we suggest that the emissions of CH4 from the India region is 51.2 1.6 Tg yr1 during the period of 20092014.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.JAG.2020.102130", "year": 2020, "title": "Trend analysis and first time observations of sulphur dioxide and nitrogen dioxide in South Africa using TROPOMI/Sentinel-5 P data", "abstract": "The 17 Sustainable Development Goals (SDGs) aim to end extreme poverty and create a healthy, sustainable world by the year 2030. Goal 7 is of interest to this study as it targets access to clean and affordable energy. However, in this study we show that the energy created in South Africa is not necessary clean. South Africa has numerous coal-fired power station located in the Mpumalanga (MP), Gauteng (GP) and Limpopo (LP) provinces. These power station produce tons of toxic pollutants including sulphur dioxide (SO2), nitrogen dioxide (NO2) and sulphates (SO4). These pollutants are known to have a negative impact on human health, climate and the environment. In this study we use the sequential Mann-Kendall test to investigate the 39 year (19802019) trends of SO2, NO2 and SO4 from these source areas. We also report for the first time on the observations of SO2 and NO2 from the Sentinel-5 P sensor over South Africa. Increasing trends of SO2 were observed in the MP, LP and GP regions. The increase was mostly due to the emissions from coal-fired power stations. Moreover, the increase of SO2 over the years could be due to the increasing demand in electricity, aging power stations and the low quality of coal used. Sentinel-5 P observations of SO2 and NO2 over South Africa were observed in the MP, GP and LP regions as a result of coal-fired power stations. Dispersion of SO2 and NO2 over South Africa were observed in the winter months, while confined SO2 and NO2 in the source region were observed in the summer months.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.117319", "year": 2020, "title": "Analysis of the atmospheric dust in Africa: The breathable dust's fine particulate matter PM2.5 in correlation with carbon monoxide", "abstract": "The dust has direct effects on people's health and climate change; so, this research studied the remotely sensed dust deposition in Africa from 1980 to 2018, and the dust's particulate matter of 2.5 m size (or PM2.5), in particular, which pollutes the breathable air. PM2.5 is studied in comparison with multispectral carbon monoxide (CO), an abundant atmospheric air pollutant in central Africa. CO is an atmospheric gaseous pollutant for which the smoke, a gaseous aerosol from incomplete combustion processes, is the biggest source. The literature clarifies that both the particulate matter and the CO endanger human health while breathed in. The dust from the desert of Sahara is windblown all over the world. CO, in Africa, is from the anthropogenic fire and volcanic eruptions' smoke; these are two good reasons to have focused on Africa. Due to the big size of Africa, five sub-regions are set; these are the western, central, northern, eastern and southern sub-regions. The Goddard interactive online visualization and analysis infrastructure (GIOVANNI) has been a bridge to the collected remote sensing data, in this research. The data was collected online, from the measurement of pollution in the troposphere (MOPITT) as well as a second version of the modern era retrospective analysis for research and applications (MERRA-2); the analysis was done by a joint of the software tools, worth noting is the Arc GIS. As the amount of African dust dramatically increased by 2000; the heaviest in 2004, results are based on the selected dust deposition over 20002018: time-averaged maps, correlations, and quantitative estimations are reported in this research. The heaviest annual dust deposition reached 25.3 t/km2 over the year 2004, in Liberia, a focal point of study for the western sub-region. An important finding: the dust's PM2.5 positively correlated with multispectral CO from November to May; the positively high correlation coefficient was 0.86 in April 2018. The negative correlation between the two measurements started from June to October; the negatively high correlation was 0.68 in October 2015; this research discussed the possible reasons. This research recommends some onsite studies about the real figures and facts about the dust's effects on health, in all the seasons; thus, an alert to policymakers who would set some strategies to mitigate the dust hazards on the health of African inhabitants, neighbors, and visitors.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.SCS.2020.102100", "year": 2020, "title": "Impact of urban and industrial features on land surface temperature: Evidences from satellite thermal indices", "abstract": "Land surface transformations associated to the urbanization has impacted local climates and terrestrial surface energy processes. The occurrence of higher temperatures in urbanized areas when compared to rural and natural areas is called surface urban heat island (SUHI). The aim of this work was to investigate different remote sensing thermal indices and their impact in an urbanized and industrialized city in Southeast Brazil. This municipality constitutes an interesting case of middle-sized city, between two big cities, that might be currently undergoing unsustainable growth. Landsat satellite images were used to derive the thermal indices based on Land Surface Temperature (LST). The results showed that high LST values were concentrated in urban and industrial areas, with buildings, impermeable pavements and sparse vegetation. Urbanized and poorly vegetated areas showed high SUHI intensity. Vegetated areas had the best thermal comfort in town. Industries and parking lots were frequently classified as SUHI and were also considered as urban hot spots. The type of materials used in constructing these areas seems to be a reason for the higher temperatures. Further studies are needed in order to better understand the thermal conductivity of those materials and to plan how to reduce temperature in such areas.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1186/S40168-019-0776-5", "year": 2020, "title": "Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities", "abstract": "The capacity of reef-building corals to tolerate (or adapt to) heat stress is a key factor determining their resilience to future climate change. Changes in coral microbiome composition (particularly for microalgal endosymbionts and bacteria) is a potential mechanism that may assist corals to thrive in warm waters. The northern Red Sea experiences extreme temperatures anomalies, yet corals in this area rarely bleach suggesting possible refugia to climate change. However, the coral microbiome composition, and how it relates to the capacity to thrive in warm waters in this region, is entirely unknown.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S12526-019-01032-Z", "year": 2020, "title": "Strong upwelling conditions drive differences in species abundance and community composition along the Atlantic coasts of Morocco and Western Sahara", "abstract": "Upwelling strongly influences the composition and dynamics of coastal communities by affecting species abundances, recruitment, dispersal and distribution. Coastal upwelling areas are key model regions to study the responses of coastal species to climate change because they are characterized by cooler water conditions and experience lower warming rates than adjacent regions, making them effective control or refuge sites. This is particularly true for the benthic species of rocky shores in upwelling areas because they are sedentary, inhabit the interface between marine and terrestrial habitats, are exposed to extremely severe and variable environmental conditions and often live near their tolerance limits. We sampled roughly 2000 km of the Atlantic coast of Morocco and Western Sahara to assess the influence of upwelling cells on patterns of diversity and abundance of northern African rocky shore species. We recorded 186 taxa, providing clarification of the distribution of 141 algae and documenting nine new species records for Morocco and Western Sahara. The results emphasize the influence of upwelling on the abundance and distribution of these organisms. The contrast between non-upwelling and upwelling areas highlights the direct and indirect importance of water temperature in shaping these communities, pointing to the consequences of large-scale warming. Such warming is likely to threaten intertidal species that already live close to their thermal tolerance limits and are not buffered by the effects of upwelling.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1017/JOG.2019.100", "year": 2020, "title": "Black carbon and mineral dust on two glaciers on the central Tibetan Plateau: sources and implications", "abstract": "Sources and implications of black carbon (BC) and mineral dust (MD) on two glaciers on the central Tibetan Plateau were estimated based on in situ measurements and modeling. The results indicated that BC and MD accounted for ~11 1% and 4 0% of the albedo reduction relative to clean snow, while the radiative forcing varied between 11 and 196 and 189 W m2, respectively. Assessment of BC and MD contributions to the glacier melt can reach up 88 to 434 and 35 to 187 mm w.e., respectively, contributing ~923 and 410% of the total glacier melt. A footprint analysis indicated that BC and MD deposited on the glaciers originated mainly from the Middle East, Central Asia, North China and South Asia during the study period. Moreover, a potentially large fraction of BC may have originated from local and regional fossil fuel combustion. This study suggests that BC and MD will enhance glacier melt and provides a scientific basis for regional mitigation efforts.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.29077/MEM_15/SABATES", "year": 2019, "title": "Fish spawning strategies in the northwestern Mediterranean Sea", "abstract": "The Mediterranean is globally considered an oligotrophic sea.\nHowever, there are some places or certain seasons in which mechanisms\nthat enhance fertility may occur. These mechanisms, and related\nprocesses, are especially relevant in maintaining fish populations\nwhen they take place during the period of larval development. This\ncontribution analyzes how environmental conditions occurring\nin the NW Mediterranean, at local and seasonal scales, determine\nthe temporal and spatial patterns of fish reproductive activity in\nthe region. The structure of the bathymetry, diversity of adult fish\nhabitats and hydrodynamic mechanisms conditioning the primary\nproduction of the region (e.g., shelf-slope density front and associated\ncurrent, continental water inflows, winter mixing, stratification\nof the water column) determine the location of spawning and the\ndistribution patterns of fish eggs and larvae. A pronounced seasonal\nvariability regarding both the number of species and the number\nof fish larvae in the plankton can be observed throughout the year.\nMost NW Mediterranean fish reproduce during the springsummer\nstratification period, when the phytoplankton biomass values at the\nupper layers of the water column are lower than in winter. The\ndevelopment of the Deep Chlorophyll Maximum in this period and\nthe high zooplankton biomass associated to it offers an important food\nsource for the larvae. Additionally, during this period the inputs of\ncontinental waters are one of the fertilization mechanisms of surface\nwaters and some species, as anchovy, takes advantage of this situation.\nAutumnwinter is the period with lower ichthyoplankton diversity,\nbeing dominated by sardine. Vertical mixing during winter is one\nof the mechanisms that enhance productivity. Overall, fish species\nshow reproductive strategies and larval fish behavior that allow them\nto take advantage of the available resources throughout the seasonal\ncycle. These strategies, together with the high ecological efficiency\nof oligotrophic systems, contribute to the relatively high yield of\nMediterranean fisheries. In a context of global change, understanding\nof the mechanisms relating environmental changes to the extent of\nspatial and temporal location of suitable spawning habitats of fish is\na key first step to predicting and projecting such future changes, and\nthereby adapting to these changes.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSENV.2019.117237", "year": 2020, "title": "Absorbing aerosol influence on temperature maxima: An observation based study over India", "abstract": "Increasing trends in summer-time temperature maxima (Tmax) over India, show consequent increases in the intensity and frequency of heatwave events in recent years. Heat waves have been largely attributed to large-scale meteorological blocking, characterized by subsidence, clear skies and low soil moisture, in observational studies, or greenhouse gas enhancements in model studies. While radiative effects of absorbing aerosols are acknowledged, the association of absorbing aerosols with temperature maxima has not been investigated comprehensively. In the current study, statistical tools (such as correlation and Granger causality) were applied to long term (19792013) satellite and ground based observations to evaluate influence of absorbing aerosols on Tmax in north-west India (Tmax-NW). Regional absorbing aerosol index (AAI) in the north-west (AAI-NW) and central-India (AAI-CI) showed co-variability with Tmax-NW, implying connections to both local and non-local absorbing aerosols. The effects persisted on seasonal and heatwave event scales, becoming stronger on heatwave days with presence of enhanced AAI loadings. Causal effects of AAI-NW and AAI-CI were identified on Tmax-NW with a lag of 111 days, across multiple years, thereby establishing the influence of absorbing aerosols on heatwave events. The absence of confounding effects of surface pressure on these links suggests that, even during heat wave events linked to atmospheric blocking, absorbing aerosols can further enhance temperature maxima and related heatwave intensity.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.RSER.2019.109478", "year": 2020, "title": "Solar irradiance time series derived from high-quality measurements, satellite-based models, and reanalyses at a near-equatorial site in Brazil", "abstract": "This study analyzes five years of 1-min solar global horizontal irradiance (GHI) and direct normal irradiance (DNI) observations obtained at Petrolina (northeast Brazil). Quality-assured hourly and daily averages are obtained after applying filters and methodologies based on a Baseline Solar Radiation Network (BSRN) quality-control procedure. To calculate correct hourly averages, a minimum fraction of 20% of valid GHI or DNI minutely data is needed, as well as at least 60% of valid days to calculate correct daily-mean monthly values. An asymmetric diurnal pattern is found in GHI and DNI during all months, attributed to consistently higher cloudiness in the morning. The quality-assured hourly and monthly-mean GHI and DNI time series are compared to estimates from 11 solar databases regularly used in solar resource assessment studies: CAMS, CERES, ERA5, INPE, MERRA-2, Meteonorm, NASA-POWER, NSRDB, SARAH, SWERA-BR, and SWERA-US. For hourly GHI values, a range of RMS differences is found between the best (CAMS, 17.3%) and the worst (MERRA-2, 38.9%) results. The latter database is also affected by a larger bias (18.7%) than CAMS (4%). Larger RMS differences are found with hourly DNI, in a range extending from 37% (CAMS) to 63.4% (ERA5). Biases are all above 12%, except for CERES (1%). For long-term mean-monthly GHI results, low biases of less than 1% are obtained with CAMS, CERES and NASA-POWER, whereas MERRA-2 overestimates (13%). Larger biases are found for mean-monthly DNI, spanning between CAMS (3%) and Meteonorm (18.4%). Overall, CAMS appears the most consistent solar database for long-term irradiance time series at Petrolina. The significant differences found here between modeled databases are larger than expected, and underline the importance of regional validation studies like this one to decrease the incidence of uncertainties in solar resource assessments on the design and performance of solar energy projects.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.AGRFORMET.2019.107640", "year": 2019, "title": "Performance of major mechanized rainfed agricultural production in Sudan: Sorghum vulnerability and resilience to climate since 1970", "abstract": "Food security in the African Sahel has frequently been threatened by climate variability and change. A large part of the farming system in the arid and semi-arid region of Sudan is heavily rainfed, with sorghum representing the major crop. This study sheds light on the performance of sorghum production in the major mechanized sector in Sudan since 1970. Despite a significant extensification of the mechanized cultivated area of sorghum, a drastic loss of area at harvest took place during 19702016. The sorghum production showed both increases and decreases in the average over time besides high year-to-year variability. Synchronous with the above findings, a significant steady decline of sorghum yield occurred from the 1970s level (744.3 kg/ha) to 476.6 kg/ha since 1982. Based on the ratio of growing season precipitation to reference evapotranspiration, a Standardized Multi-Criteria Drought Index (SMCDI) for the period 19412015 was introduced using three drought characteristics, namely drought severity, dry spell and time relative frequency of drought. There occurred 23 mild to extreme droughts and 17 mild to extreme wet cases over the period 1970-2015. Aggregation of the SMCDI with climatic sorghum yield revealed highly variable performance of this crop. Accordingly, 26 vulnerable and 20 resilient sorghum yield years were discernible under drought, near normal or wet conditions due to a combination of factors not only climate, i.e. physio-geographic, socio-economic and institutional factors. Apart from the regional analysis, one representative state was also selected for further in-depth spatio-temporal assessment of the SMCDI, integrated Normalized Difference Vegetation Index (iNDVI), Modified Vegetation Condition Index (MVCI), sorghum yield, precipitation and reference evapotranspiration data over the period 20012014. The results also underscored the spatio-temporal and local-scale vulnerability of the farming system under study to climate variability. Such findings urge for interventions in the mechanized rainfed sorghum farming system to enable improvement of its performance, drought vulnerability reduction, development of alternatives, and achievement of food security.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.RSER.2019.109247", "year": 2019, "title": "Wavelet-based 3-phase hybrid SVR model trained with satellite-derived predictors, particle swarm optimization and maximum overlap discrete wavelet transform for solar radiation prediction", "abstract": "The accurate prediction of global solar radiation (GSR) with remote sensing in metropolitan, regional and remote, yet solar-rich sites, is a core requisite for cleaner energy utilization, monitoring and conversion of renewable energy into usable power. Data-driven models that investigate the feasibility of solar-fueled energies, face challenges in respect to identifying their appropriate input data as such variables may not be available at all sites due to a lack of environmental monitoring system. In this paper, the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite-derived predictors are employed to train three-phase hybrid SVR model for monthly GSR prediction. Firstly, to acquire relevant model input features, MODIS variables are screened with the Particle Swarm Optimization (PSO) algorithm, and secondly, a Gaussian emulation method of sensitivity analysis is incorporated on all screened variables to ascertain their relative role in predicting GSR. To address pertinent issues of non-stationarities, PSO selected variables are decomposed with Maximum Overlap Discrete Wavelet Transformation prior to its incorporation in Support Vector Regression (SVR), constructing a three-phase PSO-W-SVR hybrid model where the hyper-parameters are acquired by evolutionary (i.e., PSO & Genetic Algorithm) and Grid Search methods. Three-phase PSO-W-SVR hybrid model is benchmarked with alternative machine learning models. Thirty-nine model scenarios are formulated: 13 without feature selection (e.g., SVR), 13 with feature selection (e.g., PSO-SVR for two-phase models) and the remainder 13 with feature selection strategy coupled with data decomposition algorithm (e.g., PSO-W-SVR leading to a three-phase model). Metrics such as skill score (RMSESS), root mean square error (RMSE), mean absolute error (MAE), Willmotts (WI), Legates & McCabes (E1) and NashSutcliffe coefficients (ENS) are applied to comprehensively evaluate prescribed models. Empirical results register high performance of three-phase hybrid PSO-W-SVR models, exceeding the prescribed alternative models. High predictive ability evidenced by a low RRMSE and high E1 ascertains PSO-W-SVR hybrid model as considerably favorable in its capability to be enriched by MODIS satellite-derived variables. Maximum Overlap Discrete Wavelet Transform algorithm is also seen to provide resolved patterns in satellite variables, leading to a superior performance compared to the other data-driven model. The research avers that a three-phase hybrid PSO-W-SVR model can be a viable tool to predict GSR using satellite derived data as predictors, and is particularly useful for exploration of renewable energies where satellite footprint are present but regular environmental monitoring systems may be absent.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.JASTP.2019.06.003", "year": 2019, "title": "Atmospheric anomalies associated with Mw>6.0 earthquakes in Pakistan and Iran during 20102017", "abstract": "Recent advances on satellite-based measurement of different atmospheric constituents at different heights provide sufficient evidences of short and long-term earthquake (EQ) precursors. In this paper, atmospheric anomalies are investigated related to three large magnitude Mw > 6.0 EQs in Pakistan and Iran during 20102017 (i.e., January 18, 2011 (Mw 7.2, Southwestern Pakistan), April 16, 2013 (Mw 7.7, East of Khash Iran) and February 07, 2017 (Mw 6.3, Pasni, Pakistan)). For this purpose, satellite based Outgoing Longwave Radiation (OLR), Surface Temperature (ST), Aerosol Optical Depth (AOD) and NO2 are investigated by statistical bounds of median and standard deviation for two months before and one month after the occurrence of each event. We study the spatial OLR anomaly from National Oceanic and Atmospheric Administration/National Center for Environmental Prediction (NOAA/NCEP). Evidences suggest that abnormal atmospheric anomalies occur within one month before the main shock. For example, in case of Mw 7.2 southwestern Pakistan EQ, significant perturbations in daytime OLR are detected up to 21 days before the main shock, justifying the existence of huge amounts of energy over the tectonic lineaments. The OLR anomaly correlated with ST, AOD and NO2 during 1521 days before the main shock, which may be attributed to the same event. Similarly, the OLR, ST, AOD and NO2 show irregularities before the 2013, Mw 7.7 East of Khash Iran EQ, where all the anomalies occur 910 days before the main shock. The anomalous OLR over the epicenter suggests the authenticity of all the temporal perturbations in the atmospheric parameters related to Mw 7.7 (Iran event). Furthermore, the atmospheric parameters are analyzed temporally by the statistical bounds before the Mw 6.3 (Pasni, Pakistan) EQ. All the parameters behave abnormally during 1015 days following the Mw 6.3 Pakistan EQ and similarly subsequent spatial OLR enhancement over the epicenter may lead to the conclusion of an extensive energy emanation. The anomalies detected are consistent with the processes of stress activation of proxy defects at the Lithosphere-Atmosphere interface in the seismic breeding zone.", "labels": [ { "id": 5, "name": "Earthquakes" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S12040-019-1204-8", "year": 2019, "title": "Linkage of aerosol optical depth with rainfall and circulation parameters over the Eastern Gangetic Plains of India", "abstract": "The aerosol optical depth (AOD) is an important physical parameter and dimensionless number. The possible link between AOD and variability of summer monsoon rainfall and surface temperature over the densely populated Gangetic Plain may be used to assess change in weather and climate over the Plain. For examining the impact of AOD on summer monsoon rainfall and surface temperature, monthly data of AOD for the period of 20002015 are obtained from a remotely sensed moderate resolution imaging spectro-radiometer sensor at 550 nm and at a surface resolution of $$1{^{\\circ }}\\times 1{^{\\circ }}$$11. For the period of 20002015, rainfall and surface temperature data at a resolution of $$1{^{\\circ }}\\times 1{^{\\circ }}$$11are obtained from Indian Meteorological Department (IMD) and surface wind data are obtained from National Centers for Environmental Prediction (NCEP). Summer monsoon rainfall and AOD are inversely related during 20002015. On an average, a difference in the mean monthly surface maximum and minimum temperatures increases (decreases) with a decrease (increase) of AOD. The high degree of correlation exists between AOD and a difference in $$T_{\\mathrm{max}}$$Tmaxand $$T_{\\mathrm{min}}$$Tminduring January to JuneJuly. In winter months, relative strength of negative vorticity over the Gangetic Plain and positive vorticity in the adjacent area may be cause of more dispersion of AOD in February in comparison with that in December and January and therefore more AOD is noticed in January and December.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/JOC.6189", "year": 2019, "title": "Evaluation of evapotranspiration estimates from observed and reanalysis data sets over Indian region", "abstract": "In this study, we have computed the evapotranspiration (ET) from the input variables of India Meteorological Department (IMD) for different stations in Monsoon Core Region (MCR) of India and Indian Peninsular Region (IPR) and compared with the ERA Interim (ERA-I) and CRU ET data sets. While studying the discrepancies among the data sets, rainfall (source: IMD gridded), relative humidity (source: ERA Interim gridded), air temperature (source: IMD gridded) and soil moisture (source: TRMM/LPRM/TMI-Model) were made use to illustrate the ET variations. When compared with IMD ET, our results show the CRU ET is underestimated but maintained the close pattern over MCR and IPR during South West (SW) monsoon (JuneSeptember) and North East (NE) monsoon (OctoberDecember) period, respectively. ERA-I ET bounded to have mixed response over MCR and are higher than the IMD ET over IPR. Daily comparison of the IMD and ERA-I ET data sets shows a large bias during the beginning of SW monsoon (June month) compared to other months. Site wise correlations show the substantial positive correlations between IMD and CRU ET over MCR than IPR. Overall analysis shows the monsoon features were better explained by the variations in IMD ET compared to CRU and ERA-I ET data sets. The reported disparities among the data sets play an important role in the choice of selection for different applications such as water resource assessments, crop water requirements, monitoring of droughts etc.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019MS001655", "year": 2019, "title": "Modeling the Sources and Chemistry of Polar Tropospheric Halogens (Cl, Br, and I) Using the CAM-Chem Global Chemistry-Climate Model", "abstract": "Current chemistry climate models do not include polar emissions and chemistry of halogens. This work presents the first implementation of an interactive polar module into the very short-lived (VSL) halogen version of the Community Atmosphere Model with Chemistry (CAM-Chem) model. The polar module includes photochemical release of molecular bromine, chlorine, and interhalogens from the sea-ice surface, and brine diffusion of iodine biologically produced underneath and within porous sea-ice. It also includes heterogeneous recycling of inorganic halogen reservoirs deposited over fresh sea-ice surfaces and snow-covered regions. The polar emission of chlorine, bromine, and iodine reach approximately 32, 250, and 39 Gg/year for Antarctica and 33, 271, and 4 Gg/year for the Arctic, respectively, with a marked seasonal cycle mainly driven by sunlight and sea-ice coverage. Model results are validated against polar boundary layer measurements of ClO, BrO, and IO, and satellite BrO and IO columns. This validation includes satellite observations of IO over inner Antarctica for which an iodine leapfrog mechanism is proposed to transport active iodine from coastal source regions to the interior of the continent. The modeled chlorine and bromine polar sources represent up to 45% and 80% of the global biogenic VSLCl and VSLBr emissions, respectively, while the Antarctic sea-ice iodine flux is 10 times larger than that from the Southern Ocean. We present the first estimate of the contribution of polar halogen emissions to the global tropospheric halogen budget. CAM-Chem includes now a complete representation of halogen sources and chemistry from pole-to-pole and from the Earth's surface up to the stratopause.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S00704-019-02862-4", "year": 2019, "title": "Land-sea contrasts for climatic lightning activity over Indian region", "abstract": "The land-ocean convective contrasts observed by the satellite-driven data from the Tropical Rainfall Measuring Mission for the year 1998 to 2014 (17 years) are analysed to examine the role of static land surface relative to the dynamic ocean surface for the lightning flash counts (FC). We present the relationship between the lightning flash counts per convective available potential energy (CAPE) (FC/CAPE), the product of CAPE and rainfall (CAPE RF) and Bowen ratio, FC (land/ocean) and AOD (land/ocean) and FC (land/ocean) and maximum updraft speed (land/ocean) to examine the land-ocean contrasts over the Indian region. The results show that FC/CAPE over Indian land increases by up to 520% with respect to FC/CAPE over Indian oceanic regions. The land-ocean contrast seems to be a result of increase of Bowen ratio and FC over land by up to 800% as compared with Bowen ratio and FC over ocean surface. The increase of CAPE over land is by up to 47% relative to CAPE over ocean with corresponding increase of maximum updraft speed over land by up to 117% with respect to maximum updraft speed over ocean. The temperature profiles over the land and ocean show the same temperature in the lower troposphere, followed by a temperature difference of 8 C between land and ocean at about 16000 m during pre-monsoon and post-monsoon periods. The product of CAPE with RF over land is higher by 66% to that of oceanic region with aerosol load (AOD) of about 49% more over land as compared with that of ocean. The results demonstrate the warming contrasts of land-ocean in a comparative analysis of FC, CAPE, RF and AOD in the tropics.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SOLENER.2019.02.040", "year": 2019, "title": "Surface albedo and reflectance: Review of definitions, angular and spectral effects, and intercomparison of major data sources in support of advanced solar irradiance modeling over the Americas", "abstract": "This study defines albedo and reflectance in the context of solar applications. It examines the main sources of surface albedo data that can be used to help solar irradiance modeling efforts, such as undertaken by the National Renewable Energy Laboratory (NREL) over the Americas, for instance, per the National Solar Radiation Database (NSRDB). The MODIS-based albedo database, as used as input to derive historical time series of solar irradiance in the current version of the NSRDB, is compared to other sources of global gridded data over the Americas in general and some specific areas in particular. The particular role of snow cover is analyzed. It is found that, in the current MODIS-based NSRDB implementation, snow-impacted areas have been assigned a too high albedo in general because of the lack of consideration for the antagonistic effect of surface roughness, among other factors. Other albedo databases, such as CMSAF, MINES-ParisTech or the ERA5 reanalysis, do not display such high albedos at latitudes above 40N. The gap-free and snow-free MODIS MCD43GF product is found affected by a long-term downward trend over some areas and out-of-phase seasonal effects over other areas, in comparison with MERRA-2 reanalysis data in particular. Comparisons with actual albedo measurements at the arid Desert Rock site in Nevada also show that albedo data derived from land surface models are affected by systematic bias. Five albedo databases are intercompared for the area around Ivanpah Playa, California, which has great importance in both remote sensing and solar applications. Various aspects of the proper usage of albedo data in solar radiation modeling are discussed, regarding calculations of both the backscattering process and reflections on a tilted surface: spatial resolution, temporal resolution, angular effects, and spectral effects. An important distinction is made between the use of albedo data at 4 km resolution for backscattering calculations and at 10 m resolution for transposition calculations to tilted planes, which might additionally require spectral information for monofacial or bifacial PV applications. It is shown that the tilted calculations usually performed in solar resource assessments are far from realistic in the case of most large-scale PV applications, for which a more suitable methodological approach is described. For such needs, the limitations of the current sources of high-resolution reflectance data are discussed. The impact of surface albedo estimation errors on the estimation of backscattered irradiance over snowy areas is evaluated. It is found non-negligible, and even large under cloudy conditions.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1186/S40068-019-0135-3", "year": 2019, "title": "An overview of climate change in Iran: facts and statistics", "abstract": "The climate change fact is intensive among the Middle East countries and especially Iran. Among the Middle East countries, Iran will experience an increase of 2.6 C in mean temperatures and a 35% decline in precipitation in the next decades. In vice versa, Iran by total greenhouse gas (GHG) emissions nearly to 616,741 million tons of CO2 is the first responsible country to climate change in the Middle East, and seventh in the world. The high-level contribution of Iran to emissions of GHG depends on a significant production of oil, gas, and rapid urbanization. The present study aimed to reveal an overview of climate change facts and statistics in Iran.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 10, "name": "Greenhouse Gases" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S11356-019-04602-7", "year": 2019, "title": "Impact of dust storm on phytoplankton bloom over the Arabian Sea: a case study during March 2012", "abstract": "Dust storms affect the primary productivity of the ocean by providing necessary micronutrients to the surface layer. One such dust storm during March 2012 led to a substantial reduction in visibility and enhancement in aerosol optical depth (AOD) up to ~ 0.8 (AOD increased from 0.1 to 0.9) over the Arabian Sea. We explored the possible effects and mechanisms through which this particular dust storm could impact the oceans primary productivity (phytoplankton concentration), using satellite-borne remote sensors and reanalysis model data (20032016). The climatological analyses revealed anomalous March 2012 in terms of dust deposition and enhancement in phytoplankton concentration in the month of March during 20032016 over this region. The studied dust storm accounts for increase in the daily average surface dust deposition rate from ~ 3 to ~53 mg m2 day1, which is followed by a significant enhancement in the chlorophyll-a (Chl_a) concentration (~ 2 to ~9 mg m3). We show strong association between a dust storm and an event of anomalously high biological production (with a 4-day forward lag) in the Arabian Sea. We suggest that the increase in biological production results from the superposition of two complementary processes (deposition of atmospheric nutrients and deepening of the mixed layer due to dust-induced sea surface temperature cooling) that enhance nutrient availability in the euphotic layer.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1016/J.ECSS.2019.02.026", "year": 2019, "title": "Giant kelp forests at critical light thresholds show compromised ecological resilience to environmental and biological drivers", "abstract": "Replacement of kelp and fucoid forests by low biomass turfing communities or urchin barrens has been identified in temperate marine ecosystems worldwide. Variation in the mechanisms of decline (e.g., urchin grazing, temperature stress) and apparent driving stressors (e.g., overfishing, sedimentation, global warming) has greatly limited the development of generalized management strategies. Thresholds of urchin density and thermal tolerance for habitat-forming seaweeds are increasingly well established, yet thresholds of turbidity are rarely considered. Given the universal requirement for light in aquatic macrophytes, estimation of photosynthetically active radiation (PAR) limits may help underpin frameworks for better management of terrestrial stressors. Here I have examined spatial and temporal variability of PAR in forests of the giant kelp Macrocystis pyrifera across a gradient of exposure to land-derived sediments. Exposure to excess suspended sediments pushed PAR below critical thresholds for net sporophyte growth (<1.0 mol m2 day1), affecting giant kelp densities, but also impacting a range of ecological metrics including: fucoid density; laminarian density; beta diversity metrics; subcanopy composition; and urchin density. While kelps and fucoids responded to similar light thresholds, kelps appear to be vulnerable to physical disruption by sediments whereas fucoids are tolerant of physical disruption mechanisms, but vulnerable to declining light availability. Light thresholds of 1.0 mol m2 day1 may be a useful target for management of stressors affecting water clarity (e.g., sedimentation, eutrophication), with universal applicability across diverse groups of aquatic photoautotrophs.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.ATMOSRES.2019.01.013", "year": 2019, "title": "Aerosol and cloud droplet characteristics over Ganges Valley during break phase of monsoon: A case study", "abstract": "Unique airborne observations made 330 km south of Mt. Everest during the Cloud-Aerosol Interaction Precipitation Enhancement EXperiment (CAIPEEX) 2014 are presented in this case study. These observations provide the vertical profile and elemental composition of aerosols from single particle analysis during the break period. An aerosol dome was also documented from the horizontal transect across the Varanasi city. The boundary layer was dominated by light scattering fine mode aerosols mainly a mixture of dust and pollution. The individual particle characterization revealed complex mixing states within the same aerosol aggregate. Externally mixed aerosols were present at the cloud bases. Elemental composition of aerosol particles collected from free atmosphere contained signatures of aged pollution with heavy metals, carbonaceous particles and radioactive elements. Cloud processed aerosols were also noted in the neighborhood of deep convective clouds. Shallow and deep cumulus clouds developing in the haze layer revealed distinct dropsize distributions. Shallow cumulus clouds embedded in the haze layer showed narrow droplet size distribution and were narrower than the ones observed for premonsoon conditions. Deep cumulus tops in the neighborhood of rapidly developing convection showed broad, bimodal droplet size distribution attributing to droplet evaporation and entrainment effects. Aerosol sampling near these cloud tops showed aggregates of particles that are internally mixed.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1007/S00704-018-2466-9", "year": 2019, "title": "Northerly wind trends along the Portuguese marine coast since 1950", "abstract": "Wind is a marine coastal factor that is little understood but has a strong interaction with biological productivity. In this study, northerly wind trends in three regions of the Portuguese coast (Northwestern: NW, Southwestern: SW, and Southern: S) were analyzed. Two datasets with long-term (ICOADS: 19602010) and short-term data (Satellite: 19892010) were used to complement one another. The study revealed the northerly wind yearly data to be non-stationary and highly variable between years. Overall, the northerly wind intensity increased throughout the 1960s regardless of the area and dataset. Between 1960 and 2010, the northerly wind increased at a linear rate of 0.24, 0.09, and 0.15 m s-1 per decade in the NW, SW, and S coastal regions, respectively. The rate was higher in recent decades (19882009), with the wind intensity increasing by 0.4, 0.3, and 0.3 ms-1 per decade in the NW, SW, and S regions, respectively. Analyses of the sudden shifts showed significant increases in northerly wind intensities after 2003, 2004, and 1998 in the NW, SW, and S coast, respectively. Exceptions were found for autumn (September for short-term data), when a decrease in northerly winds was observed in recent decades, regardless of the area, and for summer, when no changes in wind trends were recorded in the NW and SW. The long-term data also showed a major increase in northerly winds in winter (January and February), which is the recruitment season for many small and medium-sized pelagic fish. The increase in the intensity of the northerly winds over the past two decades and the past half-century occurred at a higher rate than was estimated by the IPCC for the next century.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/ECY.2563", "year": 2019, "title": "Moonlight enhances growth in larval fish", "abstract": "Moonlight mediates trophic interactions and shapes the evolution of life-history strategies for nocturnal organisms. Reproductive cycles and important life-history transitions for many marine organisms coincide with moon phases, but few studies consider the effects of moonlight on pelagic larvae at sea. We evaluated effects of moonlight on growth of pelagic larvae of a temperate reef fish using master chronologies of larval growth constructed from age-independent daily increment widths recorded in otoliths of 321 individuals. We found that daily growth rates of fish larvae were enhanced by lunar illumination after controlling for the positive influence of temperature and the negative influence of cloud cover. Collectively, these results indicate that moonlight enhances growth rates of larval fish. This pattern is likely the result of moonlight's combined effects on foraging efficiency and suppression of diel migrations of mesopelagic predators, and has the potential to drive evolution of marine life histories.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.4236/GEP.2018.64002", "year": 2018, "title": "Long Term Assessment of Aerosol Radiative Forcing over Selected Sites of East Africa", "abstract": "Atmospheric aerosols have contributed to radiative forcing through direct and indirect mechanisms. Aerosol effects are important in computing radiative forcing estimates for the past, current and future climate. In this study, a comprehensive assessment of regional aerosol radiative forcing, Optical Properties of Aerosol and Clouds (OPAC) model (wavelength range of 0.25 - 4.0 m) over selected sites in East Africa was done. Aerosol optical properties constituted the inputs of a Radiative Transfer Model (RTM). Op-tical properties investigated included Aerosol Optical Depth (AOD), Single Scattering Albedo (SSA) and Asymmetry Parameter (AP). Aerosol Radiative Forcing (ARF) during the study period at the surface (SFC), top of the atmosphere (TOA) and the atmosphere (ATM) was estimated to be -18.4 1.4 Wm-2, +1.1 0.3 Wm-2 and +19.5 2.5 Wm-2, respectively. This corresponds to an increment in net atmospheric forcing at a heating rate of about 0.55 0.05 K/day (0.41 0.03 to 0.78 0.03 K/day) in the lower troposphere. The study points out the significant role played by atmospheric aerosols in climate modification over the area of study. It is recommended that a further assessment be done in view of uncertainties that may impact on the findings and which were not within the scope of this research.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S41208-018-0116-8", "year": 2019, "title": "Range Extensions of the Whitespotted Boxfish, Ostracion meleagris Shaw, 1796, in the East and West Coasts of the Baja California Peninsula, Mexico", "abstract": "The Whitespotted boxfish Ostracion meleagris Shaw, 1796 is a reef resident distributed along the Indo Pacific, but at the Baja California Peninsula, Mexico, this fish has been reported only in the southern region, with a northern limit at 24.2N inside the Gulf of California. Here we document the presence of O. meleagris in 17 sites along the central gulf, with an extreme record at Tortuga Island (27.445N, almost 400 km north of its accepted range), and also in two locations of the western Baja California Peninsula (Alijos Rocks and Puerto San Carlos, at 24N). These findings represent more examples of a recently observed trend in which several species of tropical fish have expanded their distribution range towards the inner Gulf of California and in the Pacific side of the peninsula, as a possible response to the reported warming that occurs in the region.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1134/S0001433818040229", "year": 2018, "title": "Changes in Vertical Distribution and Column Content of NO2 under the Influence of Sudden Stratospheric Warmings", "abstract": "Characteristic features of changes in the vertical distribution and column content of NO2, total ozone, and stratospheric temperature have been revealed as a result of major sudden stratospheric warmings (SSWs). Strong negative anomalies of column NO2, total ozone and stratospheric temperature are caused by the displacement of the stratospheric circumpolar vortex aside from the pole. Strong positive anomalies of column NO2 and total ozone are observed more frequently under SSWs accompanied by splitting of the stratospheric circumpolar vortex and are caused by the transport of stratospheric air from the low latitudes. Major SSWs can lead to significant changes in the vertical profile of NO2. The changes in different stratospheric layers can be opposite to each other when the edge of the polar vortex is over a site of ground-based observations.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.15666/AEER/1605_57575770", "year": 2018, "title": "Temporal and spatial variations of NO2 over Saudi Arabia and identification of major hotspot areas during 2005-2014 by using satellite data.", "abstract": "The present study was designed to analyze the concentration of tropospheric NO 2 over\nSaudi Arabia for a decade from 2005-2014 based on observations from satellite borne Ozone\nMonitoring Instrument (OMI). The spatial analysis has identified two hotspots: Jeddah and Riyadh.\nThe result of temporal analysis shows increase of 1.45%, 3.15% and 3.10% per year over Saudi\nArabia, Jeddah and Riyadh respectively. The Linear Regression analysis and Analysis of Variance\n(ANOVA) have been performed to analyze the relationship between meteorological parameters,\nseasons, years and concentration of NO 2 . The results show that temperature and NO 2 are moderately\ncorrelated whereas wind and humidity give negative correlation. The major causes of elevated NO 2\nover the hotspots are road traffic and the fossil fuel combustion for electrical power generation.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2018.05.039", "year": 2018, "title": "Standard or local solar spectrum Implications for solar technologies studies in the Atacama desert", "abstract": "Knowledge of the solar spectrum is essential for the design and study of numerous technologies. Due to the area considered, the harsh conditions and the difficulty for accessing to some zones, information and measurement on local parameters and spectral resource are scarce. This fact, along with the special atmospheric conditions prevailing in Atacama Desert, has led to increasing interest on the part of the solar industry to ascertain the spectral variation respect to that of other places around the world. Considering the standard spectrum for a typical air mass as 1.5, the evaluation of PV module behaviour or device calibration under real conditions can generate a source of uncertainty where spectra may differ. This preliminary paper aims to study the influence of using the standard or local spectra in photovoltaic technologies in Atacama Desert, in order to highlight the necessity for a long-term ground-based measurement campaign. For that purpose, a first approach to the spatio-temporal average of solar spectrum in the Atacama Desert from satellite databases is estimated. Then, local spectra are compared against the Reference Spectra in order to show the differences in studies on solar energy applications. Long-term satellite database information is used to average the atmospheric parameters, such as Aerosol Optical Depth, Ozone, Precipitable Water Vapour, Albedo and Relative Humidity, for the entire Atacama Desert area and is then used to obtain the mean Global tilted Irradiance and Direct plus Circumsolar Irradiance solar spectrum. Finally, to study the influence that the shape of the local spectrum has on the performance of the different solar technologies, the photo-current density of two different solar cell types were studied under Atacama and standard conditions. The results indicate that there are considerable differences with the ASTM G173-03 reference spectra for short wavelengths, especially in the UV spectral range, which is 55% points higher than the reference, which influences in the performance of the solar technologies.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RSE.2018.05.003", "year": 2018, "title": "Self-adaptive differential evolutionary extreme learning machines for long-term solar radiation prediction with remotely-sensed MODIS satellite and Reanalysis atmospheric products in solar-rich cities", "abstract": "Designing predictive models of global solar radiation can be an effective renewable energy feasibility studies approach to resolve future problems associated with the supply, reliability and dynamical stability of consumable energy demands generated by solar-powered electrical plants. In this paper we design and present a new approach to predict the monthly mean daily solar radiation (GSR) by constructing an extreme learning machine (ELM) model integrated with the Moderate Resolution Imaging Spectroradiometer (MODIS)-based satellite and the European Center for Medium Range Weather Forecasting (ECMWF) Reanalysis data for solar rich cities: Brisbane and Townsville, Australia. A self-adaptive differential evolutionary ELM (i.e., SaDE-ELM) is proposed, utilizing a swarm-based ant colony optimization (ACO) feature selection to select the most important predictors for GSR, and the SaDE-ELM is then benchmarked with nine different data-driven models: a basic ELM, genetic programming (GP), online sequential ELM with fixed (OS-ELM) and varying (OSVARY-ELM) input sizes, and hybridized model including the particle swarm optimized-artificial neural network model (PSO-ANN), genetic algorithm optimized ANN (GA-ANN), PSO-support vector machine model (PSO-SVR), genetic algorithm optimized-SVR model (GA-SVR) and the SVR model optimized with grid search (GS-SVR). A comprehensive evaluation of the SaDE-ELM model is performed, considering key statistical metrics and diagnostic plots of measured and forecasted GSR. The results demonstrate excellent forecasting capability of the SaDE-ELM model in respect to the nine benchmark models. SaDE-ELM outperformed all comparative models for both tested study sites with a relative mean absolute and a root mean square error (RRMSE) of 2.6% and 2.3% (for Brisbane) and 0.8% and 0.7% (for Townsville), respectively. Majority of the forecasted errors are recorded in the lowest magnitude frequency band, to demonstrate the preciseness of the SaDE-ELM model. When tested for daily solar radiation forecasting using the ECMWF Reanalysis data for Brisbane study site, the performance resulted in an RRMSE 10.5%. Alternative models evaluated with the input data classified into El Nino, La Nina and the positive and negative phases of the Indian Ocean Dipole moment (considering the impacts of synoptic-scale climate phenomenon), confirms the superiority of the SaDE-ELM model (with RRMSE 13%). A seasonal analysis of all developed models depicts SaDE-ELM as the preferred tool over the basic ELM and the hybridized version of ANN, SVR and GP model. In accordance with the results obtained through MODIS satellite and ECMWF Reanalysis data products, this study ascertains that the proposed SaDE-ELM model applied with ACO feature selection, integrated with satellite-derived data is adoptable as a qualified tool for monthly and daily GSR predictions and long-term solar energy feasibility study especially in data sparse and regional sites where a satellite footprint can be identified.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ASR.2018.06.030", "year": 2018, "title": "Passive microwave response associated with two main earthquakes in Tibetan Plateau, China", "abstract": "The thermal anomalies associated with earthquakes using satellite infrared data are being studied in different parts of the world for more than three decades. The thermal anomalies have emerged as one of the potential earthquake precursor. However, often cloud cover obstructs detection of the thermal anomalies. Compared to infrared, passive microwave sensors provide information about the thermal radiations under any weather conditions. In the present study, we have carried out detailed analysis of brightness temperature data derived from the Defense Meteorological Space Program (DMSP) Special Sensor Microwave/Imager (SSM/I) to determine thermal anomalies associated with the 1997 Manyi and 2001 Kokoxili earthquakes. Brightness temperature data for 13 years period from 1996 to 2008 observed from F13 satellite were considered to avoid difference in the sensor sensitivity. Based on 9 years background data that ignoring data for the years in which strong earthquake occurred, we computed Index of Microwave Radiation Anomaly (IMRA) over the Manyi-Yushu Fault (MYF) and Kun Lun Fault (KLF) zones, Tibetan Plateau. Our results indicate that the microwave brightness temperature at 19.35 GHz has higher sensitivity to the seismic anomalies in comparison to the other higher frequency channels. The IMRA with multi-region, multi-frequency, and multi-parameter variation were analyzed to validate our results. In addition, variation of different parameters (microwave brightness temperature, near surface air temperature and carbon monoxide-CO) observed for Kokoxili earthquake shows the transfer process of thermal anomalies from the focal region to the atmosphere during the preparation and occurrence of earthquake. Passive microwave satellite data combined with other surface and atmospheric parameters provide better understanding of physical mechanism of thermal anomalies associated with earthquakes.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.5194/ACP-18-10289-2018", "year": 2018, "title": "Long-term observations of cloud condensation nuclei over the Amazon rain forest Part 2: Variability and characteristics of biomass burning, long-range transport, and pristine rain forest aerosols", "abstract": "Abstract. Size-resolved measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted over a full seasonal cycle at the remote Amazon Tall Tower Observatory (ATTO, March 2014February 2015). In a preceding companion paper, we presented annually and seasonally averaged data and parametrizations (Part 1; Pohlker et al., 2016a). In the present study (Part 2), we analyze key features and implications of aerosol and CCN properties for the following characteristic atmospheric conditions: Empirically pristine rain forest (PR) conditions, where no influence of pollution was detectable, as observed during parts of the wet season from March to May. The PR episodes are characterized by a bimodal aerosol size distribution (strong Aitken mode with DAit 70 nm and NAit 160 cm3, weak accumulation mode with Dacc 160 nm and Nacc 90 cm3), a chemical composition dominated by organic compounds, and relatively low particle hygroscopicity (Ait 0.12, acc 0.18). Long-range-transport (LRT) events, which frequently bring Saharan dust, African biomass smoke, and sea spray aerosols into the Amazon Basin, mostly during February to April. The LRT episodes are characterized by a dominant accumulation mode (DAit 80 nm, NAit 120 cm3 vs. Dacc 180 nm, Nacc 310 cm3), an increased abundance of dust and salt, and relatively high hygroscopicity (Ait 0.18, acc 0.35). The coarse mode is also significantly enhanced during these events. Biomass burning (BB) conditions characteristic for the Amazonian dry season from August to November. The BB episodes show a very strong accumulation mode (DAit 70 nm, NAit 140 cm3 vs. Dacc 170 nm, Nacc 3400 cm3), very high organic mass fractions ( 90 %), and correspondingly low hygroscopicity (Ait 0.14, acc 0.17). Mixed-pollution (MPOL) conditions with a superposition of African and Amazonian aerosol emissions during the dry season. During the MPOL episode presented here as a case study, we observed African aerosols with a broad monomodal distribution (D 130 nm, NCN,10 1300 cm3), with high sulfate mass fractions ( 20 %) from volcanic sources and correspondingly high hygroscopicity (< 100 nm 0.14, >100nm 0.22), which were periodically mixed with fresh smoke from nearby fires (D 110 nm, NCN,10 2800 cm3) with an organic-dominated composition and sharply decreased hygroscopicity (<150nm 0.10, >150nm 0.20). Insights into the aerosol mixing state are provided by particle hygroscopicity () distribution plots, which indicate largely internal mixing for the PR aerosols (narrow distribution) and more external mixing for the BB, LRT, and MPOL aerosols (broad distributions). The CCN spectra (CCN concentration plotted against water vapor supersaturation) obtained for the different case studies indicate distinctly different regimes of cloud formation and microphysics depending on aerosol properties and meteorological conditions. The measurement results suggest that CCN activation and droplet formation in convective clouds are mostly aerosol-limited under PR and LRT conditions and updraft-limited under BB and MPOL conditions. Normalized CCN efficiency spectra (CCN divided by aerosol number concentration plotted against water vapor supersaturation) and corresponding parameterizations (Gaussian error function fits) provide a basis for further analysis and model studies of aerosolcloud interactions in the Amazon.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.SCITOTENV.2017.12.183", "year": 2018, "title": "Light absorption properties of brown carbon over the southeastern Tibetan Plateau", "abstract": "We present a study of the light-absorbing properties of water-soluble brown carbon (WS-BrC) and methanol-soluble brown carbon (MeS-BrC) at a remote site (Lulang, 3326m above sea level) in the southeastern Tibetan Plateau during the period 20152016. The light absorption coefficients at 365nm (babs365) of WS-BrC and MeS-BrC were the highest during winter and the lowest during monsoon season. MeS-BrC absorbs about 1.5 times higher at 365nm compared to WS-BrC. The absorption at 550nm appears lower compared to that of 365nm for WS-BrC and MeS-BrC, respectively. Higher average value of the absorption Angstrom exponent (AAE, 365550nm) was obtained for MeS-BrC (8.2) than that for WS-BrC (6.9). The values of the mass absorption cross section at 365nm (MAC365) indicated that BrC in winter absorbs UVvisible light more efficiently than in monsoon. The results confirm the importance of BrC in contributing to light-absorbing aerosols in this region. The understanding of the light absorption properties of BrC is of great importance, especially in modeling studies for the climate effects and transport of BrC in the Tibetan Plateau.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3389/FMARS.2018.00411", "year": 2018, "title": "Large-Scale Sea Turtle Mortality Events in El Salvador Attributed to Paralytic Shellfish Toxin-Producing Algae Blooms", "abstract": "In late October and early November 2013 and 2017, hundreds of sea turtles were found dead along the Pacific coastline of El Salvador. The dead turtles were in good body condition and did not have any injuries or other major anomalies. In order to determine the role of paralytic shellfish toxins (PSTs) in this mass mortality, tissue samples, including blood, flipper, liver, kidney, stomach and intestinal contents, of dead green turtles (Chelonia mydas) and olive ridley turtles (Lepidochelys olivacea) were analyzed for PSTs using a radioactive receptor binding assay, enzyme-linked immunosorbent assay, and high performance liquid chromatography. Highest values of PSTs were detected in enteric contents in the 2013 event (730.41 g STX eq 100 g-1) and in gastric contents during the 2017 event (1616.5 g STX eq 100 g-1). During these events, intense chlorophyllA and fluorescence line height anomalies suggestive of algal blooms were identified off the coast of El Salvador. In the 2017 event, Pyrodinium bahamense was observed in samples of gastrointestinal contents from affected sea turtles. Seawater from the region where dead sea turtles were found was also analyzed, but saxitoxin-producing species were found in low abundance (5400 cell/ in 2013 and 672 cell/L in 2017). Although threshold levels of toxicity in sea turtle species are not well-characterized, our evidence suggests that these large events were the result of PST-producing algal blooms and that these blooms are a major cause of sea turtle mortality in this region.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1017/S0954102018000238", "year": 2018, "title": "Intra-population variability of the non-breeding distribution of southern giant petrels Macronectes giganteus is mediated by individual body size", "abstract": "Literature reports that body size can be associated with latitudinal distribution, for instance larger animals inhabit higher latitudes and colder habitats. This rule can be applied for species and populations within a species. The potential influence of body size on non-breeding distribution and habitat use at the intra-population level was investigated for southern giant petrels Macronectes giganteus (Gmelin) from Elephant Island, South Shetland Islands. The non-breeding distribution of 23 individuals was tracked, and total body length, culmen length, wing length, wing load and body mass were measured. Positions of core areas were used to estimate the latitudinal distribution of each individual. Smaller individuals were found to be associated more with lower latitudes, where warmer conditions and more coastal and productive waters prevail, whereas large males were associated more with higher latitudes, with colder conditions near sea ice caps, presumably feeding on carrion or preying on penguins. This association reflects a latitudinal gradient, with smaller individuals positioning themselves towards the north, and larger individuals towards the south. In this case, body size, individual distribution and habitat use were found to be associated, highlighting the importance of studying potential effects of individual body size on the ecology of seabirds.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.JAG.2018.09.017", "year": 2019, "title": "Identifying and forecasting potential biophysical risk areas within a tropical mangrove ecosystem using multi-sensor data", "abstract": "Mangroves are one of the most productive ecosystems known for provisioning of various ecosystem goods and services. They help in sequestering large amounts of carbon, protecting coastline against erosion, and reducing impacts of natural disasters such as hurricanes. Bhitarkanika Wildlife Sanctuary in Odisha harbors the second largest mangrove ecosystem in India. This study used Terra, Landsat and Sentinel-1 satellite data for spatio-temporal monitoring of mangrove forest within Bhitarkanika Wildlife Sanctuary between 2000 and 2016. Three biophysical parameters were used to assess mangrove ecosystem health: leaf chlorophyll (CHL), Leaf Area Index (LAI), and Gross Primary Productivity (GPP). A long-term analysis of meteorological data such as precipitation and temperature was performed to determine an association between these parameters and mangrove biophysical characteristics. The correlation between meteorological parameters and mangrove biophysical characteristics enabled forecasting of mangrove health and productivity for year 2050 by incorporating IPCC projected climate data. A historical analysis of land cover maps was also performed using Landsat 5 and 8 data to determine changes in mangrove area estimates in years 1995, 2004 and 2017. There was a decrease in dense mangrove extent with an increase in open mangroves and agricultural area. Despite conservation efforts, the current extent of dense mangrove is projected to decrease up to 10% by the year 2050. All three biophysical characteristics including GPP, LAI and CHL, are projected to experience a net decrease of 7.7%, 20.83% and 25.96% respectively by 2050 compared to the mean annual value in 2016. This study will help the Forest Department, Government of Odisha in managing and taking appropriate decisions for conserving and sustaining the remaining mangrove forest under the changing climate and developmental activities.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/GMD-11-4909-2018", "year": 2018, "title": "Concentrations and radiative forcing of anthropogenic aerosols from 1750 to 2014 simulated with the Oslo CTM3 and CEDS emission inventory", "abstract": "Abstract. We document the ability of the new-generation Oslo chemistry-transport model, Oslo CTM3, to accurately simulate present-day aerosol distributions. The model is then used with the new Community Emission Data System (CEDS) historical emission inventory to provide updated time series of anthropogenic aerosol concentrations and consequent direct radiative forcing (RFari) from 1750 to 2014. Overall, Oslo CTM3 performs well compared with measurements of surface concentrations and remotely sensed aerosol optical depth. Concentrations are underestimated in Asia, but the higher emissions in CEDS than previous inventories result in improvements compared to observations. The treatment of black carbon (BC) scavenging in Oslo CTM3 gives better agreement with observed vertical BC profiles relative to the predecessor Oslo CTM2. However, Arctic wintertime BC concentrations remain underestimated, and a range of sensitivity tests indicate that better physical understanding of processes associated with atmospheric BC processing is required to simultaneously reproduce both the observed features. Uncertainties in model input data, resolution, and scavenging affect the distribution of all aerosols species, especially at high latitudes and altitudes. However, we find no evidence of consistently better model performance across all observables and regions in the sensitivity tests than in the baseline configuration. Using CEDS, we estimate a net RFari in 2014 relative to 1750 of 0.17 W m2, significantly weaker than the IPCC AR5 20111750 estimate. Differences are attributable to several factors, including stronger absorption by organic aerosol, updated parameterization of BC absorption, and reduced sulfate cooling. The trend towards a weaker RFari over recent years is more pronounced than in the IPCC AR5, illustrating the importance of capturing recent regional emission changes.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S11356-018-3226-1", "year": 2018, "title": "Characterization of particulate matter and black carbon over Bay of Bengal during summer monsoon: results from the OMM cruise experiment", "abstract": "Total and size-segregated particulate matter (PM) and black carbon (BC) concentrations over the Bay of Bengal (BoB) have been measured in the summer monsoon (AugustSeptember 2014) onboard a scientific cruise conducted as a part of the Ocean Monsoon and Mixing (OMM) experiment. Role of long-range transport and prevailing meteorology in producing the observed spatio-temporal features is inferred by synthesizing the results of in situ observations in conjunction with the wind components from Modern Era Retrospective Analysis for Research and Applications (MERRA), rainfall data from Tropical Rainfall Measuring Mission (TRMM), surface BC concentration and BC Aerosol Optical Thickness (AOTBC) from MERRA2 and HYSPLIT back trajectory and dispersion model analysis. Mean values of total PM and BC mass concentrations are observed to be ~ 21.4 gm3 and ~ 393ngm3 respectively. The study has revealed significant influence of monsoon rainfall (over the measurement locations and regions through which transport occurred) on the concentration of both PM and BC over northern BoB. Results also indicate transport of aerosols with significant anthropogenic fraction, from the land regions at west to the BoB. A comprehensive analysis showed that while an eastward wind (westerly) from the Indian mainland produced an increase in PM2.5 over northern BoB, a southerly wind, mostly from the Indian Ocean, caused a decrease in concentration of PM2.5. Spectral variation of absorption coefficients of aerosols reveals that most of the BC over BoB is associated with fossil fuel combustion. Prevailing strong surface-level convergence (associated with a low-level anticyclone) resulted in accumulation and consequent enhancement of aerosol concentration over central and northern BoB during the study period. In addition, horizontal flow rates estimated across western boundary of BoB using AOTBC from MERRA2 for 10 years revealed an increasing trend in BC transport from the mainland leading to a gradual buildup in BC concentration over the regions of BoB.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S13143-018-0004-4", "year": 2018, "title": "Characteristics of Surface Urban Heat Island (SUHI) over the Gangetic Plain of Bihar, India", "abstract": "The rapid urbanisation impacts on environment, climate, agriculture, water resources trigger several problems to human beings. The present study is carried out to estimate intensity and trend of Urban Heat Island (UHI) as Surface UHI (SUHI) over towns/cities of the Gangetic plain of the state of Bihar, India, in which urban areas show relatively greater Land Surface Temperature (LST) than its rural surroundings especially during night times. The LST data (2001-14) of Moderate Resolution Imaging Spectroradiometer (MODIS) is used for five major towns/cities of Bihar namely, Bhagalpur, Gaya, Patna, Purnea and Muzzaffarpur. Each city is classified into Urban, Suburban and Rural zones as per land cover of the area. During winter months (January, February, November and December), UHI is more intense over all towns/cities. Mann-Kendall Test is applied on Surface Urban Heat Island Intensity (SUHII) in which MK-Test Statistic (S) shows a significant increasing trend. This trend would alarm a risk to increase in air pollution, heat related biohazards, energy demand in the region. This study shows the need of urban greening and proper town planning over the considered areas to mitigate the changes.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ISPRS-ANNALS-IV-4-W2-183-2017", "year": 2017, "title": "The impact of spatial and temporal resolutions in tropical summer rainfall distribution: preliminary results", "abstract": "The abundance or lack of rainfall affects peoples life and activities. As a major component of the global hydrological cycle (Chokngamwong & Chiu, 2007), accurate representations at various spatial and temporal scales are crucial for a lot of decision making processes. Climate models show a warmer and wetter climate due to increases of Greenhouse Gases (GHG). However, the models resolutions are often too coarse to be directly applicable to local scales that are useful for mitigation purposes. Hence disaggregation (downscaling) procedures are needed to transfer the coarse scale products to higher spatial and temporal resolutions. The aim of this paper is to examine the changes in the statistical parameters of rainfall at various spatial and temporal resolutions. The TRMM Multi-satellite Precipitation Analysis (TMPA) at 0.25 degree, 3 hourly grid rainfall data for a summer is aggregated to 0.5,1.0, 2.0 and 2.5 degree and at 6, 12, 24 hourly, pentad (five days) and monthly resolutions. The probability distributions (PDF) and cumulative distribution functions(CDF) of rain amount at these resolutions are computed and modeled as a mixed distribution. Parameters of the PDFs are compared using the Kolmogrov-Smironov (KS) test, both for the mixed and the marginal distribution. These distributions are shown to be distinct. The marginal distributions are fitted with Lognormal and Gamma distributions and it is found that the Gamma distributions fit much better than the Lognormal.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS9030210", "year": 2017, "title": "Fluorescence-Based Approach to Estimate the Chlorophyll-A Concentration of a Phytoplankton Bloom in Ardley Cove (Antarctica)", "abstract": "A phytoplankton bloom occurred in Ardley Cove, King George Island in January 2016, during which maximum chlorophyll-a reached 9.87 mg/m3. Records show that blooms have previously not occurred in this area prior to 2010 and the average chlorophyll-a concentration between 1991 and 2009 was less than 2 mg/m3. Given the lack of in situ measurements and the poor performance of satellite algorithms in the Southern Ocean and Antarctic waters, we validate and assess several chlorophyll-a algorithms and apply an improved baseline fluorescence approach to examine this bloom event. In situ water properties including in vivo fluorescence, water leaving radiance, and solar irradiance were collected to evaluate satellite algorithms and characterize chlorophyll-a concentration, as well as dominant phytoplankton groups. The results validated the nFLH fluorescence baseline approach, resulting in a good agreement at this high latitude, high chlorophyll-a region with correlation at 59.46%. The dominant phytoplankton group within the bloom was micro-phytoplankton, occupying 79.58% of the total phytoplankton community. Increasing sea ice coverage and sea ice concentration are likely responsible for increasing phytoplankton blooms in the recent decade. Given the profound influence of climate change on sea-ice and phytoplankton dynamics in the region, it is imperative to develop accurate methods of estimating the spatial distribution and concentrations of the increasing occurrence of bloom events.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.4209/AAQR.2017.02.0092", "year": 2018, "title": "Ground-Level NO2 in Urban Beijing: Trends, Distribution, and Effects of Emission Reduction Measures", "abstract": "The characteristic of nitrogen dioxide (NO 2 ) concentrations, including the long-term trends, spatial distribution, and\neffects of emission reduction measures-particularly those related to traffic management-were analyzed in Beijing by\nmultimethods. The annual mean concentration of NO 2 in Beijing decreased significantly from 71.0 g m 3 in 2000 to\n49.0 g m 3 in 2008 while it fluctuated between 49.0 and 58.0 g m 3 and decreased slightly from 2008 to 2015.\nUnfavorable diffusion conditions could increase NO 2 concentrations while emission reduction measures especially the\nreduced vehicle NO x emissions could decrease NO 2 concentrations significantly. The observed mean concentration of NO 2\nwas 54.47 7.71 g m 3 from 2013 to 2015, while it changed to 94.62 7.99 g m 3 for 149 heavily polluted days. The\nNO 2 concentration was lower in the northern and western regions and higher in the urban and southern areas in Beijing.\nAfter the implementation of air quality assurance measures (particularly traffic management) during the Asia-Pacific\nEconomic Cooperation Summit (APEC, 112 November, 2014) and the Parade on the 70th Victory Memorial Day for the\nChinese Peoples War of Resistance against Japanese Aggression (PARADE, 20 August3 September, 2015), the mean\nNO 2 concentrations during the APEC summit and PARADE decreased 46.2% and 39.5% respectively compared with\nthose before and after these major activities while diurnal NO 2 peaks decreased 24.5%85.3% and 4.1%70.8%,\nrespectively during the APEC summit and PARADE period. To decrease NO 2 concentrations, a high level of commitment\nmust be given to promote coordinated regional air pollution prevention and control mechanisms in Beijing and its\nsurrounding areas.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S11356-017-0521-1", "year": 2018, "title": "Spatial-temporal variations in surface ozone over Ushuaia and the Antarctic region: observations from in situ measurements, satellite data, and global models", "abstract": "The Antarctic continent is known to be an unpopulated region due to its extreme weather and climate conditions. However, the air quality over this continent can be affected by long-lived anthropogenic pollutants from the mainland. The Argentinian region of Ushuaia is often the main source area of accumulated hazardous gases over the Antarctic Peninsula. The main objective of this study is to report the first in situ observations yet known of surface ozone (O3) over Ushuaia, the Drake Passage, and Coastal Antarctic Peninsula (CAP) on board the RV Australis during the Malaysian Antarctic Scientific Expedition Cruise 2016 (MASEC16). Hourly O3 data was measured continuously for 23 days using an EcoTech O3 analyzer. To understand more about the distribution of surface O3 over the Antarctic, we present the spatial and temporal of surface O3 of long-term data (20092015) obtained online from the World Meteorology Organization of World Data Centre for greenhouse gases (WMO WDCGG). Furthermore, surface O3 satellite data from the free online NOAA-Atmospheric Infrared Sounder (AIRS) database and online data assimilation from the European Centre for Medium-Range Weather Forecasts (ECMWF)-Monitoring Atmospheric Composition and Climate (MACC) were used. The data from both online products are compared to document the data sets and to give an indication of its quality towards in situ data. Finally, we used past carbon monoxide (CO) data as a proxy of surface O3 formation over Ushuaia and the Antarctic region. Our key findings were that the surface O3 mixing ratio during MASEC16 increased from a minimum of 5 ppb to ~ 1013 ppb approaching the Drake Passage and the Coastal Antarctic Peninsula (CAP) region. The anthropogenic and biogenic O3 precursors from Ushuaia and the marine region influenced the mixing ratio of surface O3 over the Drake Passage and CAP region. The past data from WDCGG showed that the annual O3 cycle has a maximum during the winter of 30 to 35 ppb between June and August and a minimum during the summer (January to February) of 10 to 20 ppb. The surface O3 mixing ratio during the summer was controlled by photochemical processes in the presence of sunlight, leading to the depletion process. During the winter, the photochemical production of surface O3 was more dominant. The NOAA-AIRS and ECMWF-MACC analysis agreed well with the MASEC16 data but twice were higher during the expedition period. Finally, the CO past data showed the surface O3 mixing ratio was influenced by the CO mixing ratio over both the Ushuaia and Antarctic regions. Peak surface O3 and CO hourly mixing ratios reached up to ~ 38 ppb (O3) and ~ 500 ppb (CO) over Ushuaia. High CO over Ushuaia led to the depletion process of surface O3 over the region. Monthly CO mixing ratio over Antarctic (South Pole) were low, leading to the production of surface O3 over the Antarctic region.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/ATMOS8080151", "year": 2017, "title": "Caribbean Air Chemistry and Dispersion Conditions", "abstract": "The meteorological influences on Caribbean air chemistry are studied using in-situ, satellite\nand model data. Although African dust plumes join locally generated pollutants, concentrations are\nrelatively low in the eastern Caribbean due to geographic remoteness and steady oceanic trade winds.\nUrban-industrial emissions from big cities (e.g., Kingston, Santo Domingo, San Juan), agricultural\nemissions from the south, and volcanic emissions from Montserrat contribute a noticeable burden.\nConditions over Puerto Rico in the dry season (DecemberMay) provide a focus for statistical analysis\nof air chemistry constituents and weather variables that describe dispersion conditions. Monthly\nand daily air indices are formed by summing the normalized values of fine aerosols and particulates,\nlong- and short-lived trace gases from in-situ, satellite and model sources. The spatial correlation of a\ndaily Puerto Rico air index onto regional dewpoint temperature, air pressure and outgoing longwave\nradiation fields in DecemberMay 20052015 reveals the northward movement of a dry tongue\nand trough. At the climate timescale, Pacific El Nino conditions favor an increase of spring-time\nair pollution corresponding to anomalous inflow from Africa and the southern Caribbean coast.\nComposite weather patterns for a group of high air index values reflect divergent trade winds\nand a strong jet stream that imparts anticyclonic vorticity, subsidence and low humidity. This new\nunderstanding will underpin better air quality forecasts for Puerto Rico and the wider Caribbean.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1093/ICESJMS/FSX003", "year": 2017, "title": "Forecasting climate-driven changes in the geographical range of the European anchovy (Engraulis encrasicolus)", "abstract": "Anthropogenic climate change is already affecting marine ecosystems and the responses of living-resources to warming waters are various, ranging from the modifications in the abundance of key species to phenologic and biogeographic shifts. Here, we used a recently developed Ecological Niche Model (ENM) to evaluate the potential effects of global climate change on the future geographical distribution of the European anchovy. We first modelled the ecological niche (sensu Hutchinson) of the fish and projected its future spatial range using new IPCC representative concentration pathways (RCPs) scenarios and five of the latest generation of ocean-atmosphere global circulation models. We chose this multi-model and multi-scenario approach to evaluate the range of possible trajectories until the end of the century. Our projections indicate that substantial poleward shifts in the probability of anchovy occurrence are very likely and highlight areas where European anchovy fisheries are forecasted to change most. Whatever the warming scenario, our results project a reduction in the probability of occurrence in all the regions located under 48N and an increase in more northern areas. However, increases or decreases in the probability of occurrence are greater under the business-as-usual scenario RCP8.5 than under the low-emission scenario RCP2.6.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.ATMOSENV.2016.12.054", "year": 2017, "title": "Variations in particulate matter over Indo-Gangetic Plains and Indo-Himalayan Range during four field campaigns in winter monsoon and summer monsoon: Role of pollution pathways", "abstract": "Both in-situ and space-borne observations reveal an extremely high loading of particulates over the Indo-Gangetic Plains (IGP), all year around. With a burgeoning population and combustion sources (fossil fuels (FFs) and biofuels (BFs)) in close proximity to each other, the IGP is widely regarded as a hotspot for anthropogenic aerosol emission in South Asia. The deteriorating air quality over this region, particularly during winters, is a cause of major concern, since the pollutants undergo long range transport from their source regions to the Indo-Himalayan Range (IHR), Bay of Bengal (BoB) and other remote areas, polluting their pristine atmospheric conditions. Seasonal reversal in winds over the Indian mainland leads to an outflow of continental pollutants into the BoB during winters and a net advection of desert dust aerosols into the IGP from southwest Asia (SW-Asia), northwest India (NW-India) and northern Africa (N-Africa) during summers. Through the course of this study, four observational campaigns were conducted for sampling the ambient PM2.5 and PM10 during winter and summer seasons of 20142015, at multiple locations (18 sites) in the IGP, IHR, and semi-arid/arid sites towards their south and west, in order to accurately determine the inter-seasonal and inter-annual changes in the aerosol loading at the sites. We have also utilized data from Moderate Resolution Imaging Spectroradiometer (MODIS) on-board Earth Observing System (EOS) Terra satellite for estimating the columnar Aerosol Optical Depth at 550 nm (AOD550) and data from EOS Terra and Aqua satellites for discovering openly burning fires in the vicinity of sampling sites. Determination of the major source regions and key transport pathways during both seasons have also been attempted, using back-trajectory cluster analyses, as well as receptor models such as PSCF and CWT.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/978-981-10-3785-6_19", "year": 2017, "title": "Development of an Indigenous Sensor for Sub-micron Aerosol Monitoring in India", "abstract": "Environmental pollutants might be present in different media as well as\nthey can easily migrate between air, water and soil. These contaminants can migrate\nfrom one media to another. Many epidemiological studies have linked particulate\nmatter (PM) and especially the PM 2.5 (aerodynamic diameter d p < 2.5 m) mass to\nadverse cardiovascular and respiratory health effects. These health effects include\npremature mortality, asthma exacerbation, decreased lung function, and increased\nrisk of myocardial infarction among others. These tiny inhalable particles are\ncomposed of various heterogeneously mixed chemical species including sulfate,\nnitrate, ammonium ions, sea salt, organic and elemental carbon, metals, and bio-\nlogical material. Past studies have suggested that specific toxic components like\nheavy metals, PAHs or biological components like endotoxins are responsible for\nirregular heart and lung function in animal models. Accurate measurement of\ncontaminants in various media is the first step towards their effective control. This\nchapter describes the lab development and field evaluation of an inertial impaction\nbased indigenous sensor for sub-micron aerosol monitoring developed at IIT\nKanpur. Submicron particles (PM 1 ) were collected during the winter season at\nKanpur, India. These samples were chemically characterized for various species\nlike As, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Se, Ti, V, Zn, F , Cl , NO 3 ,\nSO 42 and NH 4+ . These quantitative details were used to apportion air pollutant\nsources using Positive Matrix Factorization (PMF) coupled with conditional\nprobability function (CPF) to determine the likely direction of each source from\nreceptor site. This low cost instrument is now commercially available in the Indian\nmarket.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.JVOLGEORES.2017.04.013", "year": 2017, "title": "Evidences of volcanic unrest on high-temperature fumaroles by satellite thermal monitoring: The case of Santa Ana volcano, El Salvador", "abstract": "On October 1st, 2005, Santa Ana volcano (El Salvador) underwent a VEI 3 phreatomagmatic eruption after approximately one century of rest. Casualties and damages to some of the local infrastructures and surrounding plantations were followed by the evacuation of the nearby communities. The analysis of MODIS (Moderate Resolution Imaging Spectroradiometer) infrared data reveals that the main explosion was preceded by a one-year-long thermal unrest, associated to the development of a fumaroles field, located at the western rim of the summit crater lake. By combining space-based thermal flux and ground-based measurements (seismicity, sulfur emissions and lake temperatures), we suggest that the activity observed at Santa Ana between 2004 and 2005 was driven by the gradual intrusion of an undegassed magma body at a very shallow depth. Magma injection induced thermal anomalies associated with sustained degassing from the fumaroles field and promoted the interaction between the magmatic-hydrothermal system and the overlying water table. This process culminated into the VEI 3 phreatomagmatic eruption of October 2005 that strongly modified the shallow structure of the crater area. The subsequent three-years-long activity resulted from self-sealing of the fracture system and by the opening of a new fracture network directly connecting the deeper hydrothermal system with the crater lake. Our results show that satellite-based thermal data allow us to detect the expansion of the high-temperature fumarolic field. This may precede an explosive eruption and/or a lava dome extrusion. In particular, we show that thermal records can be analyzed with other geochemical (i.e. SO2 emissions) and geophysical (seismicity) data to track a shallow magmatic intrusion interacting with the surrounding hydrothermal system. This provides a remarkable support for volcano monitoring and eruption forecasting, particularly in remote areas where permanent ground data acquisition is hazardous, expensive and difficult.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S11600-017-0051-8", "year": 2017, "title": "On the association of aerosol optical depth and total ozone fluctuations with recent earthquakes in Greece", "abstract": "A number of recent studies suggest that atmospheric changes that precede an earthquake might offer the hope of providing early warning. This study attempts to examine seismo-atmospheric anomalies around the time and the location of some of the major earthquakes in Greece in the period 20012015. Daily values of aerosol optical depth (AOD) and total ozone column (TOZ) obtained from satellite observations are used, in the time window between 25 days before and 14 days after each of these events, in a 1 1 area centred on the epicentre of each earthquake. For some of these earthquake events, abnormal increases in time series of AOD and TOZ data were detected before and after the occurrence of the earthquake. Nevertheless, in other cases, no clear anomalies were observed around the earthquake date. In addition, examining the statistics of AOD and TOZ daily values, there were many cases of prominent abnormal variations, without, however, being associated with an earthquake event. Therefore, no clear association was found between AOD and TOZ fluctuations and recent earthquakes in Greece.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.5194/ACP-17-11041-2017", "year": 2017, "title": "Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills", "abstract": "Abstract. Lumbini, in southern Nepal, is a UNESCO world heritage site of universal value as the birthplace of Buddha. Poor air quality in Lumbini and surrounding regions is a great concern for public health as well as for preservation, protection and promotion of Buddhist heritage and culture. We present here results from measurements of ambient concentrations of key air pollutants (PM, BC, CO, O3) in Lumbini, first of its kind for Lumbini, conducted during an intensive measurement period of 3 months (AprilJune 2013) in the pre-monsoon season. The measurements were carried out as a part of the international air pollution measurement campaign; SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley Atmospheric Brown Clouds). The main objective of this work is to understand and document the level of air pollution, diurnal characteristics and influence of open burning on air quality in Lumbini. The hourly average concentrations during the entire measurement campaign ranged as follows: BC was 0.330.0 g m3, PM1 was 3.6197.6 g m3, PM2. 5 was 6.1272.2 g m3, PM10 was 10.5604.0 g m3, O3 was 1.0118.1 ppbv and CO was 125.01430.0 ppbv. These levels are comparable to other very heavily polluted sites in South Asia. Higher fraction of coarse-mode PM was found as compared to other nearby sites in the Indo-Gangetic Plain region. The BC CO ratio obtained in Lumbini indicated considerable contributions of emissions from both residential and transportation sectors. The 24 h average PM2. 5 and PM10 concentrations exceeded the WHO guideline very frequently (94 and 85 % of the sampled period, respectively), which implies significant health risks for the residents and visitors in the region. These air pollutants exhibited clear diurnal cycles with high values in the morning and evening. During the study period, the worst air pollution episodes were mainly due to agro-residue burning and regional forest fires combined with meteorological conditions conducive of pollution transport to Lumbini. Fossil fuel combustion also contributed significantly, accounting for more than half of the ambient BC concentration according to aerosol spectral light absorption coefficients obtained in Lumbini. WRF-STEM, a regional chemical transport model, was used to simulate the meteorology and the concentrations of pollutants to understand the pollutant transport pathways. The model estimated values were 1. 5 to 5 times lower than the observed concentrations for CO and PM10, respectively. Model-simulated regionally tagged CO tracers showed that the majority of CO came from the upwind region of Ganges Valley. Model performance needs significant improvement in simulating aerosols in the region. Given the high air pollution level, there is a clear and urgent need for setting up a network of long-term air quality monitoring stations in the greater Lumbini region.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41559-017-0368-3", "year": 2017, "title": "The winter pack-ice zone provides a sheltered but food-poor habitat for larval Antarctic krill", "abstract": "A dominant Antarctic ecological paradigm suggests that winter sea ice is generally the main feeding ground for krill larvae. Observations from our winter cruise to the southwest Atlantic sector of the Southern Ocean contradict this view and present the first evidence that the pack-ice zone is a food-poor habitat for larval development. In contrast, the more open marginal ice zone provides a more favourable food environment for high larval krill growth rates. We found that complex under-ice habitats are, however, vital for larval krill when water column productivity is limited by light, by providing structures that offer protection from predators and to collect organic material released from the ice. The larvae feed on this sparse ice-associated food during the day. After sunset, they migrate into the water below the ice (upper 20 m) and drift away from the ice areas where they have previously fed. Model analyses indicate that this behaviour increases both food uptake in a patchy food environment and the likelihood of overwinter transport to areas where feeding conditions are more favourable in spring.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1002/2017JA023914", "year": 2017, "title": "Thunderstorm-/lightning-induced ionospheric perturbation: An observation from equatorial and low-latitude stations around Hong Kong: Lightning-Induced Perturbations", "abstract": "Total electron content (TEC) computed from the network of Global Positioning System over Hong Kong area known as Hong Kong SatRefnetwork has been used to study perturbation in the ionosphere from thunder storm activity. Data for geomagnetic quiet day (Kp < 4, on 1 April 2014) have been analyzed. The lightning activity was measured from Total Lightning sensor LS8000 over/around the Hong Kong region. Deviation in vertical TEC (DTEC) and the rate of change of TEC index (ROTI) have been derived and compared for lightning day of 1 April 2014 and nonlightning day of 7 April 2014. An analysis showed reduction in TEC during evening hour (up to 1245 UT), whereas an enhancement during nighttime hour on the lightning day is observed. The variations in DTEC during nonlightning day are found to be insignificant in comparison to that during the lightning day. The ionospheric perturbation in TEC has been noticed up to a distance around ~500 km and more from the lightning center. ROTI is found to vary from 3 to 60 total electron content unit (TECU)/min (1 TECU = 1016 el m2) on the day of thunderstorm activity, whereas ROTI is insignificant on nonlightning days. Signature of density bubbles in slant TEC data and periodicities (10100 min) in DTEC data are observed. For the same pseudorandom numbers (1, 10, 13, 23, and 28) strong amplitude scintillations are also observed at a close by station. Amplitude scintillations are proposed to be caused by plasma bubbles. The results are tentatively explained by thunderstorminduced electric fields and gravity waves.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10661-017-6336-1", "year": 2018, "title": "Long-term variations of aerosol optical depth and aerosol radiative forcing over Iran based on satellite and AERONET data", "abstract": "In this study, three different sensors of satel-\nlites including the Moderate Resolution Imaging\nSpectroradiometer (MODIS), Multi-angle Imaging\nSpectroRadiometer (MISR), and Total Ozone Mapping\nSpectrometer (TOMS) were used to study spatial and\ntemporal variations of aerosols over ten populated cities\nin Iran. Also, the Hybrid Single-Particle Lagrangian\nIntegrated Trajectory (HYSPLIT) model was used for\nanalyzing the origins of air masses and their trajectory in\nthe area. An increasing trend in aerosol concentration\nwas observed in the most studied cities in Iran during\n19792016. The cities in the western part of Iran had the\nhighest annual mean of aerosol concentration. The\nhighest aerosol optic al depth (AOD) value\n(0.76 0.51) was recorded in May 2012 over Ahvaz,\nand the lowest value (0.035 0.27) was recorded in\nDecember 2013 over Tabriz. After Ahvaz, the highest\nAOD value was found over Tehran (annual mean\n0.11 0.20). The results show that AOD increases with\nincreasing industrial activities, but the increased fre-\nquency of aerosols due to land degradation and desert-\nification is more powerful in Iran. The trajectory analy-\nsis by the HYSPLIT model showed that the air masses come from Egypt, Syria, and Lebanon and passed over\nthe Iraq and then reached to Iran during summer. Aerosol radiative forcing (ARF) has been analyzed for Zanjan (Aerosol Robotic Network site) during 20102013.\nThe ARF at surface and top of the atmosphere was\nfound to be ranging from 79 to 10W m 2 (average 33.45 W m 2 ) and from 25 to 6 W m 2 (average 12.80 W m 2 ), respectively.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/ESSD-12-789-2020", "year": 2020, "title": "Mapping the yields of lignocellulosic bioenergy crops from observations at the global scale", "abstract": "Abstract. Most scenarios from integrated assessment models (IAMs) that project greenhouse gas emissions include the use of bioenergy as a means to reduce CO2 emissions or even to achieve negative emissions (together with CCS carbon capture and storage). The potential amount of CO2 that can be removed from the atmosphere depends, among others, on the yields of bioenergy crops, the land available to grow these crops and the efficiency with which CO2 produced by combustion is captured. While bioenergy crop yields can be simulated by models, estimates of the spatial distribution of bioenergy yields under current technology based on a large number of observations are currently lacking. In this study, a random-forest (RF) algorithm is used to upscale a bioenergy yield dataset of 3963 observations covering Miscanthus, switchgrass, eucalypt, poplar and willow using climatic and soil conditions as explanatory variables. The results are global yield maps of five important lignocellulosic bioenergy crops under current technology, climate and atmospheric CO2 conditions at a 0.50.5 spatial resolution. We also provide a combined best bioenergy crop yield map by selecting one of the five crop types with the highest yield in each of the grid cells, eucalypt and Miscanthus in most cases. The global median yield of the best crop is 16.3 t DM ha1 yr1 (DM dry matter). High yields mainly occur in the Amazon region and southeastern Asia. We further compare our empirically derived maps with yield maps used in three IAMs and find that the median yields in our maps are > 50 % higher than those in the IAM maps. Our estimates of gridded bioenergy crop yields can be used to provide bioenergy yields for IAMs, to evaluate land surface models or to identify the most suitable lands for future bioenergy crop plantations. The 0.50.5 global maps for yields of different bioenergy crops and the best crop and for the best crop composition generated from this study can be download from https://doi.org/10.5281/zenodo.3274254 (Li, 2019).", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1002/PPP3.10084", "year": 2020, "title": "Enset-based agricultural systems in Ethiopia: A systematic review of", "abstract": "Societal Impact StatementEnset is a staple food for over 20 million people via its starchrich corm and pseudostem, yet it is virtually unknown outside a narrow zone of cultivation in southern Ethiopia. Due to acculturation and urbanization coupled with climate change, emerging pests and the introduction of new crops, the extensive indigenous knowledge associated with this crop is in danger of being lost, imperilling the future food security and prosperity of millions of Ethiopians. Here, we synthesize the current state of enset ethnobotanical research, identifying key gaps and challenges, and provide a framework for further enset research to safeguard this important, but neglected, tropical crop. Summary Enset (Ensete ventricosum (Welw.) Cheesman) is the major starch staple of the Ethiopian Highlands, where its unique attributes enhance the food security of approximately 20 million people and have earned it the title The Tree Against Hunger. Yet ensetbased agriculture is virtually unknown outside of its narrow zone of cultivation, despite growing wild across much of East and Southern Africa. Here, we review historical production data to show that the area of land under enset production in Ethiopia has reportedly increased 46% in two decades, whilst yield increased 12fold over the same period, making enset the second most produced crop species in Ethiopiathough we critically evaluate potential issues with these data. Furthermore, we address a major challenge in the development and wider cultivation of enset, by reviewing and synthesizing the complex and fragmented agronomic and ethnobotanic knowledge associated with this species; including farming systems, processing methods, products, medicinal uses and cultural importance. Finally, we provide a framework to improve the quality, consistency and comparability of data collected across culturally diverse ensetbased agricultural systems to enhanced sustainable use of this neglected starch staple. In conclusion, we discuss the challenges and opportunities for enset cultivation beyond its restricted distribution, and the regional food security potential it could afford smallholders elsewhere in Southern and East Africa.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1111/AJAE.12364", "year": 2022, "title": "Agricultural windfalls and the seasonality of political violence in Africa", "abstract": "AbstractWhen the prices of cereal grains rise, social unrest and conflict become likely. In rural areas, the predation motives of perpetrators can explain the positive relationship between prices and conflict. Predation happens at places and in periods where and when spoils to be appropriated are available. In predominantly agrarian societies, such opportune times align with the harvest season. Does the seasonality of agricultural income lead to the seasonality of conflict? We address this question by analyzing over 55 thousand incidents involving violence against civilians staged by paramilitary groups across Africa during the 19972020 period. We investigate the crop year pattern of violence in response to agricultural income shocks via changes in international cereal prices. We find that a yearonyear one standard deviation annual growth of the price of the major cereal grain results in a harvesttime spike in violence by militias in areas where this cereal grain is grown. This translates to a nearly 10% increase in violence during the early postharvest season. We observe no such change in violence by state forces or rebel groupsthe other two notable actors. By further investigating the mechanisms, we show that the violence by militias is amplified after plausibly rich harvest seasons when the value of spoils to be appropriated is higher. By focusing on harvestrelated seasonality of conflict, as well as actors more likely to be involved in violence against civilians, we contribute to the growing literature on the economic causes of conflict in predominantly agrarian societies.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.LANDUSEPOL.2020.105187", "year": 2021, "title": "How much land is available for sustainable palm oil?", "abstract": "Current consumption of palm oil accounts for one third of the growing world demand for vegetable oil. Amidst the burgeoning industry, huge ecological costs have been accrued within just three decades due to the rapid oil palm expansion in many parts of the world. Many oil palm plantations are linked to deforestation, biodiversity losses, land use change emissions, among other ecological problems. Total replacement of palm oil could result in even greater adverse environmental consequences as alternative crops will require more land. To satisfy the growing demands in a sustainable manner, any new plantations must be located in environmentally-benign lands. This study identifies and quantifies the potentially available lands in Malaysia and Indonesia through a novel fuzzy GIS-based land suitability analysis. Three maps were generated: biophysically suitable land, based on optimal conditions for oil palm cultivation, excluding peatlands and existing protected areas; environmentally suitable land, further excluding forest cover; and potentially available land, further excluding existing plantations and other land uses. About 4.5 million hectares of available land for new plantations have been identified that could provide 1.3 million tonnes per year of sustainable palm oil. However, most of these areas are fragmented and scattered throughout the entire archipelago, which could pose economic and socio-political hurdles to developers of sustainable palm oil. With affordable and fairer certification schemes, sustainable oil palm plantations can be achieved by smallholders on these potentially available lands. Yield improvement and biodiversity restoration of existing plantations should be the focus through revitalised sustainable agriculture and strategic forest conservation policies, respectively. The maps provide valuable policy insights into the possibility of future sustainable oil palm plantations and a starting point for on-the-ground assessment and further verification.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGEE.2022.107957", "year": 2022, "title": "Path dependencies in US agriculture: Regional factors of diversification", "abstract": "Concerns of declining agrobiodiversity and widening socioeconomic inequities in United States (US) agriculture highlight the critical need for systemic change. Despite surmounting evidence of the field and landscape scale benefits of diversifying agricultural systems, path dependencies of US agriculture present barriers to such diversification pathways. This study aims to elucidate path dependencies of agricultural landscapes that (dis)incentivize crop diversification at the regional scale through two main research questions: 1) what are the biophysical and socioecological factors most predictive of agricultural diversity across the US; and 2) how do these factors vary regionally? Using a novel panel dataset constructed from several open-source databases, we use random forest (RF) permutation variable importance measures to identify and compare the factors most predictive of county-level crop diversity across nine US regions. Our results show that climate, land use norms, and farm inputs are consistently the most important categories for predicting agricultural diversity across regions; however, variability exists in the relative regional importance of variables within these categories. Thus, factors most strongly predictive of agricultural diversity across US landscapes operate distinctly at a regional level, emphasizing the need to consider multiple scales of influence. These distinct regional relationships contribute to path dependencies that present resistance to enhancing agricultural diversity. By more appropriately addressing the regional factors of US agricultural landscapes the constrain agricultural diversification, with an eye towards future cropscapes, we can shift current path dependencies toward a more resilient and adaptive US agricultural future.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/RS13040806", "year": 2021, "title": "Crop Biomass Mapping Based on Ecosystem Modeling at Regional Scale Using", "abstract": "We evaluate the potential of using a process-based ecosystem model (BEPS) for crop biomass mapping at 20 m resolution over the research site in Manitoba, western Canada driven by spatially explicit leaf area index (LAI) retrieved from Sentinel-2 spectral reflectance throughout the entire growing season. We find that overall, the BEPS-simulated crop gross primary production (GPP), net primary production (NPP), and LAI time-series can explain 82%, 83%, and 85%, respectively, of the variation in the above-ground biomass (AGB) for six selected annual crops, while an application of individual crop LAI explains only 50% of the variation in AGB. The linear relationships between the AGB and these three indicators (GPP, NPP and LAI time-series) are rather high for the six crops, while the slopes of the regression models vary for individual crop type, indicating the need for calibration of key photosynthetic parameters and carbon allocation coefficients. This study demonstrates that accumulated GPP and NPP derived from an ecosystem model, driven by Sentinel-2 LAI data and abiotic data, can be effectively used for crop AGB mapping; the temporal information from LAI is also effective in AGB mapping for some crop types.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1088/1748-9326/ABC64D", "year": 2021, "title": "Understanding spatial variability of forage production in California grasslands: delineating climate, topography and soil controls", "abstract": "Abstract\r\n \r\n Rangelands are a key global resource, providing a broad range of ecological services and economic benefits. Californias predominantly annual rangelands cover 12% of the states land area, and the forage production is highly heterogeneous, making balancing economic (grazing), conservation (habitat) and environmental (erosion/water quality) objectives a big challenge. Herein, we examined how climate and environmental factors regulate annual grassland forage production spatially across the state and among four ecoregions using machine learning models. We estimated annual forage production at 30 m resolution over a 14 year period (20042017) using satellite images and data fusion techniques. Our satellite-based estimation agreed well with independent field measurements, with a\r\n R\r\n 2\r\n of 0.83 and RMSE of 682 kg ha\r\n 1\r\n . Forage production (14 year average) showed large spatial variability (2940 934 kg ha\r\n -1\r\n yr\r\n -1\r\n ; CV = 35%) across the study area. The gradient boosted regression tree with 11 feature variables explained 67% of the variability in forage production across the state. Precipitation amount, especially in November (germination) and April (rapid growth), was found as the dominant driver for spatial variation in forage production, especially in drier ecoregions and during drier years. Seasonal distribution of precipitation and minimum air temperature showed a relatively stronger control on forage production in wetter regions and during wet years. Additionally, solar energy became more important in wetter ecoregions. Drought reduced forage production from the long-term mean, i.e. a 33% 19% decrease in production (2397 926 kg ha\r\n -1\r\n yr\r\n -1\r\n ; CV = 38%) resulting from a 29% 5% decrease in precipitation. The machine learning based spatial analysis using big data provided insights on impacts of climate and environmental factors on forage production variation at various scales. This study demonstrates a cost-effective approach for rapid mapping and assessment of annual forage production with the potential for near real-time application.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1038/S41598-018-32779-3", "year": 2018, "title": "Drivers of within-field spatial and temporal variability of crop yield across the US Midwest", "abstract": "Abstract\r\n \r\n Not all areas of a farmers field are equal; some always produce more relative to the rest of the field, others always less, while still other areas fluctuate in their production capacity from one year to the next, depending on the interaction between climate, soil, topography and management. Understanding why the yield in certain portions of a field has a high variability over timewe call these areas\r\n unstable\r\n is of paramount importance both from an economic and an environmental point of view, as it is through the better management of these areas that we can improve yields or reduce input costs and environmental impact. In this research, we analyzed data from 338 fields cultivated with maize, soybean, wheat and cotton in the US Midwest to understand how topographic attributes and rain affect yield stability over time. In addition to this high resolution yield monitor dataset, we used publicly available data on topography, rain and soil information to test the hypothesis that within-field areas characterized by a low topographic wetness index (proxy for areas with probability of lower water content) always perform poorly (low and stable yield) compared to the rest of the field because they are drier, and that areas of a field characterized by a mid-high wetness index (high and stable yield) always perform well relative to rest of the field because they have greater water availability to plants. The relative performance of areas of a field with a very high wetness index (e.g. depressions) strongly depends on rain patterns because they may be waterlogged in wet years, yielding less than the rest of the field, or wetter during dry years, yielding more than the rest of the field. We present three different observations from this dataset to support our hypothesis. First, we show that the average topographic wetness index in the different stability zones is lower in low and stable yield areas, high in high and stable yield areas and even higher in unstable yield areas (p ", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1111/FAF.12559", "year": 2021, "title": "Ocean seascapes predict distant-water fishing vessel incursions into", "abstract": "Many of the world's most important fisheries are experiencing illegal, unreported and unregulated (IUU) fishing, thereby undermining efforts to sustainably conserve and manage fish stocks. A major challenge to ending IUU fishing is improving our ability to identify whether a vessel is fishing illegally and where illegal fishing is likely to occur in the ocean. However, monitoring the oceans is costly, time\u2011consuming, and logistically challenging for maritime authorities to patrol. To address this problem, we use vessel tracking data and machine learning to predict whether a distant\u2011water fishing vessel is fishing within the Argentine exclusive economic zone (EEZ) on the Patagonian Shelf, one of the world's most productive regions for fisheries. We combine vessel location data with oceanographic seascapes\u2014classes of oceanic areas based on oceanographic variables\u2014and other remotely sensed oceanographic variables to train a series of machine learning models of varying levels of complexity. These models are able to predict whether a distant\u2011water fishing vessel is operating inside the EEZ with 69%\u201396% confidence, depending on the year and predictor variables used. These results offer a promising step towards pre\u2011empting illegal activities, rather than reacting to them forensically.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/RS13050990", "year": 2021, "title": "Mapping Paddy Rice with Sentinel-1/2 and Phenology-, Object-Based", "abstract": "In tropical/subtropical monsoon regions, accurate rice mapping is hampered by the following factors: (1) The frequent occurrence of clouds in such areas during the rice-growing season interferes strongly with optical remote sensing observations; (2) The agro-landscape in such regions is fragmented and scattered. Rice maps produced using low spatial resolution data cannot well delineate the detailed distribution of rice, while pixel-based mapping using medium and high resolutions has significant salt-and-pepper noise. (3) The cropping system is complex, and rice has a rotation schedule with other crops. Therefore, the Phenology-, Object- and Double Source-based (PODS) paddy rice mapping algorithm is implemented, which consists of three steps: (1) object extraction from multi-temporal 10-m Sentinel-2 images where the extracted objects (fields) are the basic classification units; (2) specifying the phenological stage of transplanting from SavitzkyGolay filtered enhanced vegetation index (EVI) time series using the PhenoRice algorithm; and (3) the identification of rice objects based on flood signal detection from time-series microwave and optical signals of the Sentinel-1/2. This study evaluated the potential of the combined use of the Sentinel-1/2 mission on paddy rice mapping in monsoon regions with the Hangzhou-Jiaxin-Huzhou (HJH) plain in China as the case study. A cloud computing approach was used to process the available Sentinel-1/2 imagery from 2019 and MODIS images from 2018 to 2020 in the HJH plain on the Google Earth Engine (GEE) platform. An accuracy assessment showed that the resultant object-based paddy rice map has a high accuracy with a producer (user) accuracy of 0.937 (0.926). The resultant 10-m paddy rice map is expected to provide unprecedented detail, spatial distribution, and landscape patterns for paddy rice fields in monsoon regions.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.RAMA.2017.08.001", "year": 2018, "title": "Diverse management strategies produce similar ecological outcomes on ranches in Western Great Plains: social-ecological assessment", "abstract": "Experiments investigating grazing systems have often excluded ranch-scale decision making, which has limited our understanding of the processes and consequences of adaptive management. We conducted interviews and vegetation monitoring on 17 ranches in eastern Colorado and eastern Wyoming to investigate rancher decision-making processes and the associated ecological consequences. Management variables investigated were grazing strategy, grazing intensity, planning style, and operation type. Ecological attributes included the relative abundance of plant functional groups and categories of ground cover. We examined the environmental and management correlates of plant species and functional group composition using nonmetric multidimensional scaling and linear mixed models. After accounting for environmental variation across the study region, species composition did not differ between grazing management strategy and planning style. Operation type was significantly correlated with plant community composition. Integrated cow-calf plus yearling operations had greater annual and less key perennial cool-season grass species cover relative to cow-calfonly operations. Integrated cow-calf plus yearling ranches were able to more rapidly restock following drought compared with cow-calf operations. Differences in types of livestock operations contributed to variability in plant species composition across the landscape that may support diverse native faunal species in these rangeland ecosystems. Three broad themes emerged from the interviews: 1) long-term goals, 2) flexibility, and 3) adaptive learning. Stocking-rate decisions appear to be slow, path-dependent choices that are shaped by broader social, economic, and political dynamics. Ranchers described having greater flexibility in altering grazing strategies than ranch-level, long-term, annual stocking rates. These results reflect the complexity of the social-ecological systems ranchers navigate in their adaptive decision-making processes. Ranch decision-making process diversity within these environments precludes development of a single best strategy to manage livestock grazing.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.FORECO.2019.05.045", "year": 2019, "title": "Finding the sweet spot: Shifting optimal climate for maple syrup production in North America", "abstract": "Climate change is affecting the benefits society derives from forests. One such forest ecosystem service is maple syrup, which is primarily derived from Acer saccharum (sugar maple), currently an abundant and widespread tree species in eastern North America. Two climate sensitive components of sap affect syrup production: sugar content and sap flow. The sugar in maple sap derives from carbohydrate stores influenced by prior year growing season conditions. Sap flow is tied to freeze/thaw cycles during early spring. Predicting climate effects on syrup production thus requires integrating observations across scales and biological processes. We observed sap at 6 sugar maple stands spanning sugar maple's latitudinal range over 2\u20136 years to predict the role of climate variation on sugar content and sap flow. We found that the timing of sap collection advanced by 4.3 days for every 1 \u00b0C increase in March mean temperature, sap volume peaked at a January-May mean temperature of 1 \u00b0C, and sap sugar content declined by 0.1 \u00b0Brix for every 1 \u00b0C increase in previous May-October mean temperature. Using these empirical relationships, we projected that the sap collection season midpoint will be 1 month earlier and sap sugar content will decline by 0.7 \u00b0Brix across sugar maple's range by the year 2100 in an RCP 8.5 climate change scenario. The region of maximum sap flow is expected to shift northward by 400 km, from near the 43rd parallel to the 48th parallel by 2100. Our findings suggest climate change will have profound effects on syrup yield across most of sugar maple's range; drastic shifts in the timing of the tapping season accompanied by flat to moderate increases in syrup yield per tap in Canada contrast with declines in syrup yield and higher frequencies of poor syrup production years across most of the U.S. range.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGRFORMET.2018.11.022", "year": 2019, "title": "Annual dynamics of carbon dioxide fluxes over a rainfed alfalfa field in the US Southern Great Plains", "abstract": "A thorough investigation of annual dynamics of carbon dioxide (CO2) fluxes with respect to major controlling factors and harvest management is lacking for rainfed alfalfa (Medicago sativa L.), a high quality perennial legume forage. To address this knowledge gap, this study reports two years (April 2016 - March 2018) of eddy covariance measurements of CO2 fluxes over a rainfed alfalfa field in central Oklahoma, USA. Alfalfa yields were strongly regulated by amount and timing of rainfall. As a result, cumulative dry forage yield was 7.5 t ha1 (four harvests) in 2016 (dry year) and 10 t ha1 (five harvests) in 2017 (wet year). An optimum air temperature (Ta) and vapor pressure deficit (VPD) for net ecosystem CO2 exchange (NEE) was approximately 25 C and 2.2 kPa, respectively. The response of gross primary production (GPP) to photosynthetically active radiation (PAR) varied with growth stage of alfalfa and climatic conditions (i.e., dry or normal/wet periods). Daily (8-day averages) NEE and gross primary production (GPP) reached -8.17 and 16.69 g C m-2 d1, respectively. Magnitudes of GPP (GPPMOD) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) were < 50% of tower-derived GPP, most likely due to a smaller value (0.15 g C mol1 PAR) for light use efficiency in the GPPMOD algorithm. The observed 8-day composite ecosystem light use efficiency (ELUE) was up to 0.36 g C mol1 PAR in this study. The rainfed alfalfa field with 45 hay harvests per year showed large carbon uptake potential (e.g., cumulative NEE of -454 g C m-2 in 2017) at an annual scale. The GPP and ELUE showed a strong correspondence with MODIS-derived vegetation indices, indicating the potential of applying satellite remote sensing to upscale site-level observations of CO2 fluxes for alfalfa to larger spatial scales.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGRFORMET.2019.107775", "year": 2020, "title": "From sunlight to seed: Assessing limits to solar radiation capture and conversion in agro-ecosystems", "abstract": "Yield depends upon the amount of photosynthetically active radiation (PAR) absorbed by the crop during the growing season and its conversion into harvestable biomass. Little is known about attainable and actual efficiencies involved in absorbing incident PAR (ea) and converting it into yield (ec) in producer fields. We developed a novel approach consisting of producer data, satellite imagery, and crop modelling to assess ea and ec in agro-ecosystems. Simulated phenology and satellite imagery were used to estimate incident (IPAR) and absorbed (APAR) PAR during the crop season for 3096 soybean fields sown across the US North Central region during 20142016. Quantile regression was used to derive upper limits for ea and ec and multiple-regression analysis was performed to identify biophysical drivers of the observed variation in these two efficiencies. Differences in weather, soil, and management resulted in a wide range in crop cycle length (58126 d), total IPAR (5801250 MJ m2), and seed yield (0.86.3 Mg ha1). The relationship between yield and total APAR was curvilinear, indicating marginal yield gains in the upper APAR range. Attainable ea represented 65% of total IPAR, while attainable ec ranged from 0.6 to 1.2 g seed MJ1 depending upon total APAR. Average producer ea and ec were 14 and 29% below their attainable efficiencies. Average efficiency in converting IPAR into yield was 0.8%, with an upper limit of 1.1% derived from the 95th percentile of the field data distribution. Although weak, relationships between efficiencies and meteorological factors such as IPAR, temperature, water balance, and diffuse radiation were consistent with previous literature. There was a strong trade-off between ec and ea indicating that maximizing both efficiencies simultaneously was not possible in producer fields. Our approach can be used to determine attainable and actual efficiencies in capturing and converting radiation into yield, set realistic yield limits, and understand relationships between producer yield and management practices.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1017/WET.2021.92", "year": 2021, "title": "Influence of integrated agronomic and weed management practices on soybean canopy development and yield", "abstract": "The role of weed suppression by the cultivated crop is often overlooked in annual row cropping systems. Agronomic practices such as planting time, row spacing, tillage and herbicide selection may influence the time of crop canopy closure. The objective of this research was to evaluate the influence of the aforementioned agronomic practices and their interaction with the adoption of an effective preemergence (PRE) soil residual herbicide program on soybean canopy closure and yield. A field experiment was conducted in 2019 and 2020 in Arlington, WI, as a 2222 factorial in a randomized complete block design, including early (late April) and standard (late May) planting time, narrow (38 cm) and wide (76 cm) row spacing, conventional tillage and no-till, and soil-applied PRE herbicide (yes and no; flumioxazin 150 g ai ha1 + metribuzin 449 g ai ha1 + pyroxasulfone 190 g ai ha1). All plots were maintained weed-free throughout the growing season. In both years, early planted soybeans reached 90% green canopy cover (T90) before (7 to 9 d difference) and yielded more (188 to 902 kg ha1 difference) than the standard planted soybeans. Narrow-row soybeans reached T90 earlier than wide-row soybeans (4 to 7 d difference), but yield was similar between row spacing treatments. Conventional tillage resulted in a higher yield compared to a no-till system (377 kg ha1 difference). The PRE herbicide slightly delayed T90 (4 d or less) but had no impact on yield. All practices investigated herein influenced the time of soybean canopy closure but only planting time and tillage impacted yield. Planting soybeans earlier and reducing their row spacing expedites the time to canopy closure. The potential delay in canopy development and yield loss if soybeans are allowed to compete with weeds early in the season would likely outweigh the slight delay in canopy development by an effective PRE herbicide.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S11027-019-09852-X", "year": 2019, "title": "Climate change favors rice production at higher elevations in Colombia", "abstract": "Rice (Oriza sativa) feeds nearly half of the worlds population. Regional and national studies in Asia suggest that rice production will suffer under climate change, but researchers conducted few studies for other parts of the world. This research identifies suitable areas for cultivating irrigated rice in Colombia under current climates and for the 2050s, according to the Representative Concentration Pathway (RCP) 8.5 scenario. The methodology uses known locations of the crop, environmental variables, and maximum entropy and probabilistic methods to develop niche-based models for estimating the potential geographic distribution of irrigated rice. Results indicate that future climate change in Colombia could reduce the area that is suitable for rice production by 60%, from 4.4 to 1.8 million hectares. Low-lying rice production regions could be the most susceptible to changing environmental conditions, while mid-altitude valleys could see improvements in rice-growing conditions. In contrast to a country like China where rice production can move to higher latitudes, rice adaptation in tropical Colombia will favor higher elevations. These results suggest adaptation strategies for the Colombian rice sector. Farmers can adopt climate-resilient varieties or change water and agronomic management practices, or both. Other farmers may consider abandoning rice production for some other crop or activity.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ESSD-12-847-2020", "year": 2020, "title": "Annual oil palm plantation maps in Malaysia and Indonesia from 2001 to 2016", "abstract": "Abstract. Increasing global demand of vegetable oils and biofuels results in significant oil palm expansion in southeastern Asia, predominately in Malaysia and Indonesia. The land conversion to oil palm plantations has posed risks to deforestation (50 % of the oil palm was taken from forest during 19902005; Koh and Wilcove, 2008), loss of biodiversity and greenhouse gas emission over the past decades. Quantifying the consequences of oil palm expansion requires fine-scale and frequently updated datasets of land cover dynamics. Previous studies focused on total changes for a multi-year interval without identifying the exact time of conversion, causing uncertainty in the timing of carbon emission estimates from land cover change. Using Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR), ALOS-2 PALSAR-2 and Moderate Resolution Imaging Spectroradiometer (MODIS) datasets, we produced an annual oil palm area dataset (AOPD) at 100 m resolution in Malaysia and Indonesia from 2001 to 2016. We first mapped the oil palm extent using PALSAR and PALSAR-2 data for 20072010 and 20152016 and then applied a disturbance and recovery algorithm (Breaks For Additive Season and Trend BFAST) to detect land cover change time points using MODIS data during the years without PALSAR data (20112014 and 20012006). The new oil palm land cover maps are assessed to have an accuracy of 86.61 % in the mapping step (20072010 and 20152016). During the intervening years when MODIS data are used, 75.74 % of the detected change time matched the timing of actual conversion using Google Earth and Landsat images. The AOPD revealed spatiotemporal oil palm dynamics every year and shows that plantations expanded from 2.59 to 6.39106 ha and from 3.00 to 12.66106 ha in Malaysia and Indonesia, respectively (i.e. a net increase of 146.60 % and 322.46 %) between 2001 and 2016. The higher trends from our dataset are consistent with those from the national inventories, with limited annual average difference in Malaysia (0.2106 ha) and Indonesia (0.17106 ha). We highlight the capability of combining multiple-resolution radar and optical satellite datasets in annual plantation mapping to a large extent by using image classification and statistical boundary-based change detection to achieve long time series. The consistent characterization of oil palm dynamics can be further used in downstream applications. The annual oil palm plantation maps from 2001 to 2016 at 100 m resolution are published in the Tagged Image File Format with georeferencing information (GeoTIFF) at https://doi.org/10.5281/zenodo.3467071 (Xu et al., 2019).", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1080/21683565.2022.2163449", "year": 2023, "title": "Perspectives on agroecological transition: the case of Guacheta municipality, Colombia", "abstract": "Specialization of agriculture in the Colombian Andes has increased smallholder vulnerability to climate change and global price fluctuations and has also affected the socio-economic and environmental conditions. Promoting sustainable agriculture in the region requires a holistic understanding of complex agroecosystems. This study identifies and analyzes the main challenges for agriculture and possibilities for agroecological transition of small-scale farms in Guacheta, Colombia. Using the Tool for Agroecology Performance Evaluation (TAPE), 10 elements of agroecology and core performance criteria were evaluated on seven farms. Several key actors were then interviewed, to triangulate data and understand current challenges and possible future pathways. It was found that drier climate and variations in rainfall patterns pose major challenges to current production systems. Limited possibilities for participation in land governance, lack of interest in agriculture among young people, and lack of access to markets hinder the development of sustainable agriculture. Current specialized practices in dairy and potato production are associated with reduced agricultural biodiversity and dependency on agrochemicals, leading to weak synergies and low profitability within agroecosystems. Implementation of agroecological principles and practices such as crop and income diversification and promoting joint action in agricultural development could help overcome sustainability issues in Guacheta.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S00484-017-1492-0", "year": 2018, "title": "Modeling and improving Ethiopian pasture systems", "abstract": "The production of pasture in Ethiopia was simulated by means of a dynamic model. Most of the country is characterized by a tropical monsoon climate with mild temperatures and precipitation mainly concentrated in the JuneSeptember period (main rainy season). The production model is driven by solar radiation and takes into account limitations due to relocation, maintenance respiration, conversion to final dry matter, temperature, water stress, and nutrients availability. The model also considers the senescence of grassland which strongly limits the nutritional value of grasses for livestock. The simulation for the 19822009 period, performed on gridded daily time series of rainfall and maximum and minimum temperature with a resolution of 0.5, provided results comparable with values reported in literature. Yearly mean yield in Ethiopia ranged between 1.8 metric ton per hectare (t ha-1) (2002) and 2.6 t ha1 (1989) of dry matter with values above 2.5 t ha-1 attained in 1983, 1985, 1989, and 2008. The Ethiopian territory has been subdivided in 1494 cells and a frequency distribution of the per-cell yearly mean pasture production has been obtained. This distribution ranges from 0 to 7 t ha-1 and it shows a right skewed distribution and a modal class between 1.52 t ha-1. Simulation carried out on long time series for this peculiar tropical environment give rise to as lot of results relevant by the agroecological point of view on space variability of pasture production, main limiting factors (solar radiation, precipitation, temperature), and relevant meteo-climatic cycles affecting pasture production (seasonal and inter yearly variability, ENSO). These results are useful to establish an agro-ecological zoning of the Ethiopian territory.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1007/S10098-022-02422-X", "year": 2022, "title": "Geographic information systems-based land suitability assessment for switchgrass cultivation in marginal lands: a case study for Izmir-Turkey", "abstract": "Energy crop cultivation is considered the main factor in the rapid increase in the share of biomass energy in the future global energy supply. However, the most critical issue for the cultivation of energy crops will be establishing sustainable energy cropping systems and protecting agricultural areas devoted to food and feed crops. Therefore, the present study aims to identify key criteria for energy crop cultivation areas and to develop a Geographic information systems (GISs)- and multi-criteria evaluation model (MCE)-based methodology. This study employs a GIS-based MCE technique, including fuzzy standardization, analytic hierarchy process (AHP), and weighted overlay for analyzing land suitability to switchgrass cultivation for the case study in Izmir-Turkey. The criteria identified in this study include climatic parameters, soil characteristics, topography, and land restrictions for land-use compatibility. Climate data were employed by TerrSets Crop Climate Suitability Model to determine the climatic suitability of switchgrass in the city. Subsequently, an assessment model of land suitability for switchgrass cultivation was developed by integrating AHP in the ArcGIS environment. Here, the highest specific weight was attained for climatic suitability (0.22), and the lowest was found for elevation (0.094). Significantly, 69.4% (40,725 ha) of the potential cultivation area was moderately suitable and higher, and 30.5% (17,896 ha) was low suitable for switchgrass cultivation. Therefore, it was concluded that the applied methodology could be a practical approach for sustainable biofuels production and environmental protection and can be employed for different energy crops and regions.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-17-4063-2017", "year": 2017, "title": "Remote sensing and modelling analysis of the extreme dust storm hitting the Middle East and eastern Mediterranean in September 2015", "abstract": "Abstract. The extreme dust storm that affected the Middle East and the eastern Mediterranean in September 2015 resulted in record-breaking dust loads over Cyprus with aerosol optical depth exceeding 5.0 at 550 nm. We analyse this event using profiles from the European Aerosol Research Lidar Network (EARLINET) and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), geostationary observations from the Meteosat Second Generation (MSG) Spinning Enhanced Visible and Infrared Imager (SEVIRI), and high-resolution simulations from the Regional Atmospheric Modeling System (RAMS). The analysis of modelling and remote sensing data reveals the main mechanisms that resulted in the generation and persistence of the dust cloud over the Middle East and Cyprus. A combination of meteorological and surface processes is found, including (a) the development of a thermal low in the area of Syria that results in unstable atmospheric conditions and dust mobilization in this area, (b) the convective activity over northern Iraq that triggers the formation of westward-moving haboobs that merge with the previously elevated dust layer, and (c) the changes in land use due to war in the areas of northern Iraq and Syria that enhance dust erodibility.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.GLOPLACHA.2020.103294", "year": 2020, "title": "Global-scale daily riverine DOC fluxes from lands to the oceans with a generic model", "abstract": "The export of riverine dissolved organic carbon (DOC) to the oceans is determinant in carbon exchanges of the estuaries and oceanic food webs. Past research returned a global DOC export around 160450 TgC.yr1 by using complex process-based models or yearly average estimates that could have been misjudged. In this study, we try to understand the complex processes explaining daily DOC exports among 341 exoreic watersheds covering 71% of freshwater flows to the oceans. Based on a dataset of DOC concentrations among rivers at the global scale, we were able to link DOC concentrations to daily discharge, the ration between the soil organic carbon content and the amount of precipitations and the average air temperature in the watersheds. We have found a global riverine DOC flux of 131.6 TgC.yr1 based on daily data and a generic model. Tropical and cold watersheds are the main contributors with 49.5% and 33.3% of the global riverine DOC flux on the two last decades while temperate, semi-arid and polar basins represent 15.9%, 0.7% and 0.6%, respectively. Temporal exports range from 0.1 to 0.16 TgC.day1 in tropical areas, 0.030.32 TgC.day1 in cold areas and 0.030.08 TgC.day1 in temperate areas. Atlantic and Arctic oceans receive the most important fluxes (0.120.2 and 0.010.26 TgC.day1). In a climate change context, this generic equation could be introduced in hydrological modelling tools to predict future DOC fluxes trends.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 10, "name": "Greenhouse Gases" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/GCB.14499", "year": 2018, "title": "Global ammonia emissions from synthetic nitrogen fertilizer applications in agricultural systems: Empirical and process-based estimates and uncertainty", "abstract": "AbstractExcessive ammonia (NH3) emitted from nitrogen (N) fertilizer applications in global croplands plays an important role in atmospheric aerosol production, resulting in visibility reduction and regional haze. However, large uncertainty exists in the estimates of NH3 emissions from global and regional croplands, which utilize different data and methods. In this study, we have coupled a processbased Dynamic Land Ecosystem Model (DLEM) with the bidirectional NH3 exchange module in the Community Multiscale AirQuality (CMAQ) model (DLEMBiNH3) to quantify NH3 emissions at the global and regional scale, and cropspecific NH3 emissions globally at a spatial resolution of 0.5 0.5 during 19612010. Results indicate that global NH3 emissions from N fertilizer use have increased from 1.9 0.03 to 16.7 0.5 Tg N/year between 1961 and 2010. The annual increase of NH3 emissions shows large spatial variations across the global land surface. Southern Asia, including China and India, has accounted for more than 50% of total global NH3 emissions since the 1980s, followed by North America and Europe. Rice cultivation has been the largest contributor to total global NH3 emissions since the 1990s, followed by corn and wheat. In addition, results show that empirical methods without considering environmental factors (constant emission factor in the IPCC Tier 1 guideline) could underestimate NH3 emissions in context of climate change, with the highest difference (i.e., 6.9 Tg N/year) occurring in 2010. This study provides a robust estimate on global and regional NH3 emissions over the past 50 years, which offers a reference for assessing air quality consequences of future nitrogen enrichment as well as nitrogen use efficiency improvement.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ESSD-12-1679-2020", "year": 2020, "title": "New ground-based Fourier-transform near-infrared solar absorption measurements of XCO\u2082, XCH\u2084 and XCO at Xianghe, China", "abstract": "The column-averaged dry-air mole fractions of CO2 (XCO2), CH4 (XCH4) and CO (XCO) have been measured with a Bruker IFS 125HR Fourier-transform infrared (FTIR) spectrometer at Xianghe (39.75 N, 116.96 E, north China) since June 2018. This paper presents the site, the characteristics of the FTIR system and the measurements. The instrumental setup follows the guidelines of the Total Carbon Column Observing Network (TCCON): the near-infrared spectra are recorded by an InGaAs detector together with a CaF2 beam splitter, and the HCl cell measurements are recorded regularly to derive the instrument line shape (ILS) showing that the instrument is correctly aligned. The TCCON standard retrieval code (GGG2014) is applied to retrieve XCO2, XCH4 and XCO. The resulting time series between June 2018 and July 2019 are presented, and the observed seasonal cycles and day-to-day variations in XCO2, XCH4 and XCO at Xianghe are discussed. In addition, the paper shows comparisons between the data products retrieved from the FTIR measurements at Xianghe and co-located Orbiting Carbon Observatory-2 (OCO-2) and Tropospheric Monitoring Instrument (TROPOMI) satellite observations. The comparison results appear consistent with validation results obtained at TCCON sites for XCO2 and XCH4, while for XCO they highlight the occurrence of frequent high-pollution events. As Xianghe lies in a polluted area in north China where there are currently no TCCON sites, this site can fill the TCCON gap in this region and expand the global coverage of the TCCON measurements. The Xianghe FTIR XCO2, XCH4 and XCO data can be obtained at https://doi.org/10.18758/71021049 (Yang et al., 2019).", "labels": [ { "id": 17, "name": "Validation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-22-15981-2022", "year": 2022, "title": "Inferring and evaluating satellite-based constraints on NOx emissions estimates in air quality simulations", "abstract": "Abstract. Satellite observations of tropospheric NO2 columns can provide top-down observational constraints on emissions estimates of nitrogen oxides (NOx). Mass-balance-based methods are often applied for this purpose but do not isolate near-surface emissions from those aloft, such as lightning emissions. Here, we introduce an inverse modeling framework that couples satellite chemical data assimilation to a chemical transport model. In the framework, satellite-constrained emissions totals are inferred using model simulations with and without data assimilation in the iterative finite-difference mass-balance method. The approach improves the finite-difference mass-balance inversion by isolating the near-surface emissions increment. We apply the framework to separately estimate lightning and anthropogenic NOx emissions over the Northern Hemisphere for 2019. Using overlapping observations from the Ozone Monitoring Instrument (OMI) and the Tropospheric Monitoring Instrument (TROPOMI), we compare separate NOx emissions inferences from these satellite instruments, as well as the impacts of emissions changes on modeled NO2 and O3. OMI inferences of anthropogenic emissions consistently lead to larger emissions than TROPOMI inferences, attributed to a low bias in TROPOMI NO2 retrievals. Updated lightning NOx emissions from either satellite improve the chemical transport model's low tropospheric O3 bias. The combined lighting and anthropogenic emissions updates improve the model's ability to reproduce measured ozone by adjusting natural, long-range, and local pollution contributions. Thus, the framework informs and supports the design of domestic and international control strategies.", "labels": [ { "id": 1, "name": "Air Quality" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-20-5591-2020", "year": 2020, "title": "Anthropogenic and volcanic point source SO2 emissions derived from TROPOMI on board Sentinel-5 Precursor: first results", "abstract": "Abstract. The paper introduces the first TROPOMI-based sulfur dioxide (SO2) emissions estimates for point sources. A total of about 500 continuously emitting point sources releasing about 10 kt yr1 to more than 2000 kt yr1 of SO2, previously identified from Ozone Monitoring Instrument (OMI) observations, were analyzed using TROPOMI (TROPOspheric Monitoring Instrument) measurements for 1 full year from April 2018 to March 2019. The annual emissions from these sources were estimated and compared to similar estimates from OMI and Ozone Mapping Profiling Suite (OMPS) measurements. Note that emissions from many of these 500 sources have declined significantly since 2005, making their quantification more challenging. We were able to identify 274 sources where annual emissions are significant and can be reliably estimated from TROPOMI. The standard deviations of TROPOMI vertical column density data, about 1 Dobson unit (DU, where 1 DU =2.691016 molecules cm2) over the tropics and 1.5 DU over high latitudes, are larger than those of OMI (0.61 DU) and OMPS (0.30.4 DU). Due to its very high spatial resolution, TROPOMI produces 1220 times more observations over a certain area than OMI and 96 times more than OMPS. Despite higher uncertainties of individual TROPOMI observations, TROPOMI data averaged over a large area have roughly 23 times lower uncertainties compared to OMI and OMPS data. Similarly, TROPOMI annual emissions can be estimated with uncertainties that are 1.52 times lower than the uncertainties of annual emissions estimates from OMI. While there are area biases in TROPOMI data over some regions that have to be removed from emission calculations, the absolute magnitude of these are modest, typically within 0.25 DU, which can be comparable with SO2 values over large sources.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-11-5819-2011", "year": 2011, "title": "Global multi-year O3-CO correlation patterns from models and TES satellite observations", "abstract": "Abstract. The correlation between measured tropospheric ozone (O3) and carbon monoxide (CO) has been used extensively in tropospheric chemistry studies to explore the photochemical characteristics of different regions and to evaluate the ability of models to capture these characteristics. Here, we present the first study that uses multi-year, global, vertically resolved, simultaneous and collocated O3 and CO satellite (Tropospheric Emission Spectrometer) measurements, to determine this correlation in the middle/lower free troposphere for two different seasons, and to evaluate two chemistry-climate models. We find results that are fairly robust across different years, altitudes and timescales considered, which indicates that the correlation maps presented here could be used in future model evaluations. The highest positive correlations (around 0.8) are found in the northern Pacific during summer, which is a common feature in the observations and the G-PUCCINI model. We make quantitative comparisons between the models using a single-figure metric (C), which we define as the correlation coefficient between the modeled and the observed O3-CO correlations for different regions of the globe. On a global scale, the G-PUCCINI model shows a good performance in the summer (C=0.71) and a satisfactory performance in the winter (C=0.52). It captures midlatitude features very well, especially in the summer, whereas the performance in regions like South America or Central Africa is weaker. The UKCA model (C=0.46/0.15 for JulyAugust/DecemberJanuary on a global scale) performs better in certain regions, such as the tropics in winter, and it captures some of the broad characteristics of summer extratropical correlations, but it systematically underestimates the O3-CO correlations over much of the globe. It is noteworthy that the correlations look very different in the two models, even though the ozone distributions are similar. This demonstrates that this technique provides a powerful global constraint for understanding modeled tropospheric chemical processes. We investigated the sources of the correlations by performing a series of sensitivity experiments. In these, the sign of the correlation is, in most cases, insensitive to removing different individual emissions, but its magnitude changes downwind of emission regions when applying such perturbations. Interestingly, we find that the O3-CO correlation does not solely reflect the strength of O3 photochemical production, as often assumed by earlier studies, but is more complicated and may reflect a mixture of different processes such as transport.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/978-3-031-15374-7_1", "year": 2023, "title": "Data-Informed Models for the Coupled Dispersal of Microplastics and Related Pollutants Applied to the Mediterranean Sea", "abstract": "Abstract\r\n Microplastic pollution is a ubiquitous environmental threat, in particular to the oceans. In the marine environment, microplastics are not just passively transported by sea currents, but often get contaminated with organic pollutants during the journey. The uptake of chemicals onto microplastics can worsen the adverse effects of microplastics to marine organisms; however, investigation on this urgent phenomenon is hampered by the impossibility of monitoring and tracking such small plastic fragments during their motion at sea. This work aims at addressing the need for an effective modelling of the advectiondiffusion processes jointly involving microplastics and the pollutants they carry to further our understanding of their spatiotemporal patterns and ecological impacts, focusing on the Mediterranean Sea. Here we present the conceptual design, methodological settings, and modelling results of a novel, data-informed 2D LagrangianEulerian modelling framework that simultaneously describes (i) the Lagrangian dispersal of microplastic on the sea surface, (ii) the Eulerian advectiondiffusion of selected organic contaminants, and (iii) the gradient-driven chemical exchanges between microplastic particles and chemical pollutants in the marine environment in a simple, yet comprehensive way. Crucial to the realism of our model is exploiting the wide variety and abundance of data linked with drivers of Mediterranean marine pollution by microplastics and chemicals, ranging from national censuses to satellite data of surface water runoff and GPS ship tracking, other than the use of oceanographic reanalyses to inform microplastics motion at sea. The results of our method applied to a multi-year simulation contribute to a first basin-wide assessment of the role of microplastics as a vehicle of other pollutants of concern in the marine environment. The framework proposed here is intended as a flexible tool to help advance knowledge towards a comprehensive description of the multifaceted threat of marine plastic pollution and an informed support to targeted mitigation policies.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1007/978-3-319-67474-2_14", "year": 2018, "title": "Multi-scale Simulations of Atmospheric Pollutants Using a Non-hydrostatic Icosahedral Atmospheric Model", "abstract": "We have developed a seamless global-to-regional model to calculate atmospheric aerosol chemistry by coupling existing aerosol and chemical modules to a global cloud-system-resolving model (NICAM-Chem). The model can simulate air pollutants with various grid sizes ranging from global low resolution (~200 km) on yearly scales to regional high resolution (~10 km) on monthly scales and global high resolution (<10 km) on weekly scales. To date, we have confirmed that the NICAM-Chem simulated aerosols at low-to-high resolutions, and global-to-regional scales are generally comparable to validated observations. Furthermore, the very recent availability of cutting-edge computational capabilities provided by the K computer at RIKEN in Japan enabled us to perform seasonal air pollution simulations with a high global resolution model (14 km), which generally reproduced the observed aerosol distributions. In this paper, we introduce the following application studies using the NICAM-Chem model: future scenario experiments, downscaling using results obtained by a coupled atmosphere-ocean model, estimation of human health due to PM2.5, simulations of radioactive matter using a regional model, and aerosol assimilation by a localized ensemble transform Kalman filter.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1088/1748-9326/AC3695", "year": 2021, "title": "Interannual variation of reactive nitrogen emissions and their impacts on PM2. 5 air pollution in China during 2005\u20132015", "abstract": "Abstract\r\n \r\n Emissions of reactive nitrogen as ammonia (NH\r\n 3\r\n ) and nitrogen oxides (NO\r\n \r\n x\r\n \r\n ), together with sulfur dioxide (SO\r\n 2\r\n ), contribute to formation of secondary PM\r\n 2.5\r\n in the atmosphere. Satellite observations of atmospheric NH\r\n 3\r\n , NO\r\n 2\r\n , and SO\r\n 2\r\n levels since the 2000s provide valuable information to constrain the spatial and temporal variability of their emissions. Here we present a bottom-up Chinese NH\r\n 3\r\n emission inventory combined with top-down estimates of Chinese NO\r\n \r\n x\r\n \r\n and SO\r\n 2\r\n emissions using ozone monitoring instrument satellite observations, aiming to quantify the interannual variations of reactive nitrogen emissions in China and their contributions to PM\r\n 2.5\r\n air pollution over 20052015. We find small interannual changes in the total Chinese anthropogenic NH\r\n 3\r\n emissions during 20052016 (12.013.3 Tg with over 85% from agricultural sources), but large interannual change in top-down Chinese NO\r\n \r\n x\r\n \r\n and SO\r\n 2\r\n emissions. Chinese NO\r\n \r\n x\r\n \r\n emissions peaked around 2011 and declined by 22% during 20112015, and Chinese SO\r\n 2\r\n emissions declined by 55% in 2015 relative to that in 2007. Using the GEOS-Chem chemical transport model simulations, we find that rising atmospheric NH\r\n 3\r\n levels in eastern China since 2011 as observed by infrared atmospheric sounding interferometer and atmospheric infrared sounder satellites are mainly driven by rapid reductions in SO\r\n 2\r\n emissions. The 20112015 Chinese NO\r\n \r\n x\r\n \r\n emission reductions have decreased regional annual mean PM\r\n 2.5\r\n by 2.33.8\r\n \r\n g m\r\n 3\r\n . Interannual PM\r\n 2.5\r\n changes due to NH\r\n 3\r\n emission changes are relatively small, but further control of agricultural NH\r\n 3\r\n emissions can be effective for PM\r\n 2.5\r\n pollution mitigation in eastern China.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/GMD-13-3489-2020", "year": 2020, "title": "Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model (C-TRAIL Model v1. 0) derived from the Community Multiscale Air Quality \u2026", "abstract": "Abstract. This paper introduces a novel Lagrangian model (Concentration Trajectory Route of Air pollution with an Integrated Lagrangian model, C-TRAIL version 1.0) output from a Eulerian air quality model for validating the sourcereceptor direct link by following polluted air masses. To investigate the concentrations and trajectories of air masses simultaneously, we implement the trajectory-grid (TG) Lagrangian advection scheme in the CMAQ (Community Multiscale Air Quality) Eulerian model version 5.2. The TG algorithm follows the concentrations of representative air packets of species along trajectories determined by the wind field. The diagnostic output from C-TRAIL accurately identifies the origins of pollutants. For validation, we analyze the results of C-TRAIL during the KORUS-AQ campaign over South Korea. Initially, we implement C-TRAIL in a simulation of CO concentrations with an emphasis on the long- and short-range transport effects. The output from C-TRAIL reveals that local trajectories were responsible for CO concentrations over Seoul during the stagnant period (1722 May 2016) and during the extreme pollution period (2528 May 2016), highly polluted air masses from China were distinguished as sources of CO transported to the Seoul Metropolitan Area (SMA). We conclude that during the study period, long-range transport played a crucial role in high CO concentrations over the receptor area. Furthermore, for May 2016, we find that the potential sources of CO over the SMA were the result of either local transport or long-range transport from the Shandong Peninsula and, in some cases, from regions north of the SMA. By identifying the trajectories of CO concentrations, one can use the results from C-TRAIL to directly link strong potential sources of pollutants to a receptor in specific regions during various time frames.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ATMOSENV.2017.08.054", "year": 2017, "title": "Distinguishing the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks in \u201cAPEC Blue\u201d", "abstract": "Air quality are strongly influenced by both emissions and meteorological conditions. During the Asia Pacific Economic Cooperation (APEC) week (November 511, 2014), the Chinese government implemented unprecedented strict emission control measures in Beijing and surrounding provinces, and then a phenomenon referred to as APEC Blue (rare blue sky) occurred. It is challenging to quantify the effectiveness of the implemented strict control measures solely based on observations. In this study, we use the WRF-Chem model to distinguish the roles of meteorology, emission control measures, regional transport, and co-benefits of reduced aerosol feedbacks during APEC week. In general, meteorological variables, PM2.5 concentrations and PM2.5 chemical compositions are well reproduced in Beijing. Positive weather conditions (lower temperature, lower relative humidity, higher wind speeds and enhanced boundary layer heights) play important roles in APEC Blue. Applying strict emission control measures in Beijing and five surrounding provinces can only explain an average decrease of 17.7 g/m3 (21.8%) decreases in PM2.5 concentrations, roughly more than half of which is caused by emission controls that implemented in the five surrounding provinces (12.5 g/m3). During the APEC week, non-local emissions contributed to 41.3% to PM2.5 concentrations in Beijing, and the effectiveness of implementing emission control measures hinges on dominant pathways and transport speeds. Besides, we also quantified the contribution of reduced aerosol feedbacks due to strict emission control measures in this study. During daytime, co-benefits of reduced aerosol feedbacks account for about 10.9% of the total decreases in PM2.5 concentrations in urban Beijing. The separation of contributions from aerosol absorption and scattering restates the importance of controlling BC to accelerate the effectiveness of aerosol pollution control.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.2151/SOLA.2017-006", "year": 2017, "title": "Inverse Modeling of Asian Dust Emissions with POPC Observations: A TEMM Dust Sand Storm 2014 Case Study", "abstract": "An inverse modeling system for estimating Asian dust emissions was developed by combining the GEOS-Chem chemical transport model with the Green's function method. We applied the system to two heavy dust storms that occurred in 2014 (10-25 March and 24 May to 5 June), using surface-based polarization optical particle counter (POPC) observations at Fukuoka. Validation by independent observation datasets, including POPC measurements and PM10 observations at Seoul, showed that the use of a posteriori dust emissions improved overestimations in the a priori simulation and achieved much better agreement with observations. Satellite observations, surface synoptic observations, and modeled wind fields indicated that the major dust source region differed between the two dust storms; the major dust outbreak of one storm occurred in the northeastern Gobi Desert, whereas that of the other occurred in the southern Gobi Desert. The a posteriori dust emissions successfully reproduced this difference. Thus, the inverse modeling system developed in this study was able to improve the estimation of not only the intensity but also the geographical distribution of dust emissions.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1080/00295450.2020.1741295", "year": 2020, "title": "Hiroshima and Nagasaki Verification of an Unstructured Mesh-Based Transmutation Toolkit", "abstract": "In order to model the activated isotopes and resulting dose from a nuclear detonation in an urban environment, the Activation and Transmutation of Isotopes in an Unstructured Mesh (ACTIUM) Python toolkit has been developed to combine the unstructured meshbased particle transport capability of MCNP6.2 with the CINDER2008 transmutation code to produce quantities of interest for the post-detonation nuclear forensics and weapons effects communities. The ACTIUM toolkit has been implemented and validated with a number of test cases from a simple analytic model to a case study of the urban detonation in Nagasaki, Japan. The ACTIUM approach is the first of its kind to couple the latest release of CINDER2008 as a part of the Activation in Accelerator Radiation Environments (AARE) package with MCNP6.2 and produce transmuted quantities per time step on an unstructured mesh for the nuclear forensics and weapon effects communities. ACTIUM uses the latest ENDF/B-VIII.0, TENDL2017, and JENDL4 cross-section libraries for the transmutation calculations and includes methods for producing material cards for the initial MCNP6.2 unstructured mesh calculation based on highly detailed materials often found in urban environments on a city-specific basis.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.3390/ATMOS11070757", "year": 2020, "title": "Evaluation of WRF-Chem predictions for dust deposition in Southwestern Iran", "abstract": "The relationships between monthly recorded ground deposition rates (GDRs) and the spatiotemporal characteristics of dust concentrations in southwest Iran were investigated. A simulation by the Weather Research and Forecasting Model coupled with the Chemistry modeling system (WRF-Chem) was conducted for dust deposition during 20142015. The monthly dust deposition values observed at 10 different gauge sites (G01G10) were mapped to show the seasonal and spatial variations in dust episodes at each location. An analysis of the dust deposition samples, however, confirmed that the region along the deposition sites is exposed to the highest monthly dust load, which has a mean value of 2.4 mg cm2. In addition, the study area is subjected to seasonally varying deposition, which follows the trend: spring > summer > winter > fall. The modeling results further demonstrate that the increase in dust emissions is followed by a windward convergence over the region (particularly in the spring and summer). Based on the maximum likelihood classification of land use land cover, the modeling results are consistent with observation data at gauge sites for three scenarios [S.I, S.II, and S.III]. The WRF model, in contrast with the corresponding observation data, reveals that the rate factor decreases from the southern [S.IIIG08, G09, and G10] through [S.IIG04, G05, G06, and G07] to the northern points [S.IG01, G02, and G03]. A narrower gap between the modeling results and GDRs is indicated if there is an increase in the number of dust particles moving to lower altitudes or an increase in the dust resident time at high altitudes. The quality of the model forecast is altered by the deposition rate and is sensitive to land surface properties and interactions among land and climate patterns.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/2015JG003271", "year": 2016, "title": "Strong regional atmospheric\n 14\n C signature of respired CO\n 2\n observed from a tall tower over the midwestern United States", "abstract": "Radiocarbon in CO2 (14CO2) measurements can aid in discriminating between fast (<1 year) and slower (>5-10 years) cycling of C between the atmosphere and the terrestrial biosphere due to the 14C disequilibrium between atmospheric and terrestrial C. However, 14CO2 in the atmosphere is typically much more strongly impacted by fossil fuel emissions of CO2, and, thus, observations often provide little additional constraints on respiratory flux estimates at regional scales. Here we describe a data set of 14CO2 observations from a tall tower in northern Wisconsin (USA) where fossil fuel influence is far enough removed that during the summer months, the biospheric component of the 14CO2 budget dominates. We find that the terrestrial biosphere is responsible for a significant contribution to 14CO2 that is 2-3 times higher than predicted by the Carnegie-Ames-Stanford approach terrestrial ecosystem model for observations made in 2010. This likely includes a substantial contribution from the North American boreal ecoregion, but transported biospheric emissions from outside the model domain cannot be ruled out. The 14CO2 enhancement also appears somewhat decreased in observations made over subsequent years, suggesting that 2010 may be anomalous. With these caveats acknowledged, we discuss the implications of the observation/model comparison in terms of possible systematic biases in the model versus short-term anomalies in the observations. Going forward, this isotopic signal could be exploited as an important indicator to better constrain both the long-term carbon balance of terrestrial ecosystems and the short-term impact of disturbance-based loss of carbon to the atmosphere.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2021EA001762", "year": 2021, "title": "Regional Impact of Ozone Precursor Emissions on NOX and O3 Levels at ZOTTO Tall Tower in Central Siberia", "abstract": "Seasonal variations of the near-surface NOX (= NO + NO2) and ozone (O3) mixing ratios at Zotino Tall Tower (ZOTTO), a remote site in central Siberia, are described for years 2007-2014. Conditional probability function analysis and back trajectories are used to determine the origins of clean (continental baseline, CB) and regional emissions-influenced air. High NOX levels at the site are observed for air from industrial regions of western Siberia and Ural Mountains, whereas CB air originates from remote areas of North Eurasia within 55\u00b0-70\u00b0N. The estimated annual means of daytime O3 and NOX mixing ratios for CB air are 27.0 and 0.44 ppbv, correspondingly, versus the similar quantities of 27.9 and 0.79 ppbv for all data. Monthly ozone for CB air shows a distinct maximum in April, as is the case for Northern Hemisphere midlatitude baseline (NHMLB) air at the European inflow boundary according to the surface ozone data for Mace Head and Norwegian monitoring sites, and a minimum in late summer-early autumn reflecting a weak continental-scale ozone production from biogenic sources of ozone precursors and wildfire emissions throughout the warm season. During spring and early summer under hot weather conditions, regional anthropogenic and wildfire emissions are an important source for ozone in the continental boundary layer over southern and central Siberia, resulting in surface ozone levels compared to or larger than those observed in NHMLB air. Throughout the remaining part of year, the central North Eurasia represents a sink for tropospheric ozone on a hemispheric scale.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/GMD-11-369-2018", "year": 2018, "title": "Historical (17502014) anthropogenic emissions of reactive gases and aerosols from the Community Emissions Data System (CEDS)", "abstract": "Abstract. We present a new data set of annual historical (17502014) anthropogenic chemically reactive gases (CO, CH4, NH3, NOx, SO2, NMVOCs), carbonaceous aerosols (black carbon BC, and organic carbon OC), and CO2 developed with the Community Emissions Data System (CEDS). We improve upon existing inventories with a more consistent and reproducible methodology applied to all emission species, updated emission factors, and recent estimates through 2014. The data system relies on existing energy consumption data sets and regional and country-specific inventories to produce trends over recent decades. All emission species are consistently estimated using the same activity data over all time periods. Emissions are provided on an annual basis at the level of country and sector and gridded with monthly seasonality. These estimates are comparable to, but generally slightly higher than, existing global inventories. Emissions over the most recent years are more uncertain, particularly in low- and middle-income regions where country-specific emission inventories are less available. Future work will involve refining and updating these emission estimates, estimating emissions' uncertainty, and publication of the system as open-source software.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.SCITOTENV.2017.01.147", "year": 2017, "title": "Groundwater arsenic contamination in Burkina Faso, West Africa: Predicting and verifying regions at risk", "abstract": "Arsenic contamination in groundwater from crystalline basement rocks in West Africa has only been documented in isolated areas and presents a serious health threat in a region already facing multiple challenges related to water quality and scarcity. We present a comprehensive dataset of arsenic concentrations from drinking water wells in rural Burkina Faso (n=1498), of which 14.6% are above 10g/L. Included in this dataset are 269 new samples from regions where no published water quality data existed. We used multivariate logistic regression with arsenic measurements as calibration data and maps of geology and mineral deposits as independent predictor variables to create arsenic prediction models at concentration thresholds of 5, 10 and 50g/L. These hazard maps delineate areas vulnerable to groundwater arsenic contamination in Burkina Faso. Bedrock composed of schists and volcanic rocks of the Birimian formation, potentially harbouring arsenic-containing sulphide minerals, has the highest probability of yielding groundwater arsenic concentrations >10g/L. Combined with population density estimates, the arsenic prediction models indicate that ~560,000 people are potentially exposed to arsenic-contaminated groundwater in Burkina Faso. The same arsenic-bearing geological formations that are positive predictors for elevated arsenic concentrations in Burkina Faso also exist in neighbouring countries such as Mali, Ghana and Ivory Coast. This study's results are thus of transboundary relevance and can act as a trigger for targeted water quality surveys and mitigation efforts.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.JENVMAN.2021.114079", "year": 2022, "title": "COVID-19 lockdown closures of emissions sources in India: Lessons for air quality and climate policy", "abstract": "Reduced anthropogenic activities during the COVID-19 pandemic caused significant reductions in ambient fine particulate matter (PM2.5), SO2 and NOx concentrations across India. However, tropospheric O3 concentrations spiked over many urban regions. Moreover, reductions in SO2 and NOx (atmospheric cooling agents) emissions unmask heating exerted by warming forcers. Basing governmental guidelines, we model daily emissions reductions in CO2 and short-lived climate forcers (SLCFs) during different lockdown periods using bottom-up regional emission inventory. The transport sector, with maximum level of closure, followed by power plants and industry reduced nearly 50% to 75% emissions of CO2, primary PM2.5, SO2 and NOx, while warming SLCFs (black carbon, CH4, CO and non-methane VOCs) showed insignificant reduction from continuing activity in residential and agricultural sectors. Consequently, the analysis indicates that reduction in the emission ratio of NOx to NMVOC coincided spatially with observed increases in O3, consistent with reduced uptake of O3 from night-time NOx reactions. Also, similar reductions, occurring for longer timescales (say, a year), can potentially increase the annual warming rate over India from the positive regional temperature response, estimated using climate metric. Further, by linking ongoing policies to sectoral reductions during lockdown, this study shows that the relative pacing of implementation among policies is crucial to avoid counter-productive results. A key policy recommendation is introduction and improving efficacy of programs targeting reduction of NMVOC and warming SLCF emissions (shifts away from biomass cooking technologies, household electrification and curbing open burning of crop residues), must precede the strengthening of policies targeting NOx and SO2 dominated sectors.", "labels": [ { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/S10584-016-1863-2", "year": 2016, "title": "Droughts augment youth migration in Northern Latin America and the Caribbean", "abstract": "While evidence on the linkages between migration and climate is starting to emerge, the subject remains largely under-researched at regional scale. Knowledge on the matter is particularly important for Northern Latin America and the Caribbean, a region of the world characterized by exceptionally high migration rates and substantial exposure to natural hazards. We link individual-level information from multiple censuses for eight countries in the region with natural disaster indicators constructed from georeferenced climate data at the province level to measure the impact of droughts and hurricanes on internal mobility. We find that younger individuals are more likely to migrate in response to these disasters, especially when confronted with droughts. Youth exhibit a stronger inclination towards relocating to rural and small town settings, motivated possibly by opportunities for nearby off-farm employment and financing limitations for urban transport and living expenses. Migration decisions are mediated by national institutional arrangements. These findings highlight the importance of social protection and regional planning policies to reduce the vulnerability of youth to droughts in the future and secure their economic integration.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1109/IGARSS.2019.8898354", "year": 2019, "title": "SMAP L4 assessment of the US northern plains 2017 flash drought", "abstract": "A rapidly developing \"flash drought\" occurred over the US Northern Plains in the summer of 2017, spurred by unusually high temperatures and strong evaporative demand. The impacts of the drought included widespread reductions in rangeland and agricultural productivity that cascaded into significant economic losses. Here, we used satellite information from the NASA Soil Moisture Active Passive (SMAP) mission to clarify the nature and impact of the drought on regional vegetation growth. The model enhanced SMAP Level 4 Soil Moisture (L4SM) and Carbon (L4C) products were used with other ancillary data to examine spatial and seasonal anomalies in surface to root zone soil moisture and vegetation productivity (GPP). We find that the flash drought was triggered by a mid-July heat wave, conditioned by exceptionally low spring rainfall. The drought resulted in anomalous low soil moisture levels and regional GPP collapse, coinciding with severe (D3) to exceptional (D4) drought conditions indicated from the US Drought Monitor. The SMAP L4C GPP anomalies closely tracked reported county-level crop production anomalies for the major regional crop types, indicating generally larger productivity decline in managed croplands than surrounding natural areas. The SMAP L4 global products provide an effective indicator of vegetation growth changes and moisture-related restrictions on ecosystem productivity that are complementary with more traditional drought assessment tools.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1117/12.2324652", "year": 2018, "title": "Climate change and its impact on drought in Eastern Gansu rainfed agricultural area in Northwest China in the last thirty years", "abstract": "The monthly precipitation and temperature data,soil moisture data and NDVI data from 1981 to 2010 in Eastern Gansu were used to analyze the temperature, precipitation, soil moisture and drought change in this area. The results show that: 1) The climate in Eastern Gansu appeared a significant warming trend, and the temperature increase was extremely significant in spring, summer, autumn and winter. Among them, the spring temperature increase was the largest with the rate of 0.82 C/10a. 2) The annual precipitation has experienced a process of high-low-high in the past 30 years. Among them precipitation in spring continued to decrease, while other seasons showed increase tendency in the 21st century after a decline in the last 10 years of the 20th century. 3) The soil moisture in the whole layer (10-100cm) in spring showed a significant downward trend, especially in the surface layer. During the growth season, the water storage capacity of the whole layer of soil decreased significantly. 4) The frequency and extent of drought events in Eastern Gansu experienced a change of low-high-low process. The lowest period of drought occurred in the 1980s and the highest period occurred in the 1990s. The frequency and extent in the first 10 years of this century declined. 5) The spring drought occurred most frequently and strongest intensity in the past 30a. AVI has a good consistency with CI and soil moisture on the monitoring of drought process, but the volatility is higher.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.3390/RS14051223", "year": 2022, "title": "Retrospective Predictions of Rice and Other Crop Production in", "abstract": "Malagasy subsistence farmers, who comprise 70% of the nearly 26 million people in Madagascar, often face food insecurity because of unreliable food production systems and adverse crop conditions. The 20202021 drought in Madagascar, in particular, is associated with an exceptional food crisis, yet we are unaware of peer-reviewed studies that quantitatively link variations in weather and climate to agricultural outcomes for staple crops in Madagascar. In this study, we use historical data to empirically assess the relationship between soil moisture and food production. Specifically, we focus on major staple crops that form the foundation of Malagasy food systems and nutrition, including rice, which accounts for 46% of the average Malagasy caloric intake, as well as cassava, maize, and sweet potato. Available data associated with survey-based crop statistics constrain our analysis to 20102017 across four clusters of Malagasy districts. Strong correlations are observed between remotely sensed soil moisture and rice production, ranging between 0.67 to 0.95 depending on the cluster and choice of crop calendar. Predictions are shown to be statistically significant at the 90% confidence level using bootstrapping techniques, as well as through an out-of-sample prediction framework. Soil moisture also shows skill in predicting cassava, maize, and sweet potato production, but only when the months most vulnerable to water stress are isolated. Additional analyses using more survey data, as well as potentially more-refined crop maps and calendars, will be useful for validating and improving soil-moisture-based predictions of yield.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1007/978-981-10-8947-3_12", "year": 2018, "title": "Drought and urbanization: The case of the Philippines", "abstract": "The Philippines is highly vulnerable to drought, resulting in severe impacts on crop productivity, water availability, and food security. This chapter explores water security in the country by examining the effects of drought on risk governance and its social impacts on the 19971998 and 20152016 El Nino episodes in Metro Manila, Iloilo City, and Cebu City. During these periods, widespread dryness occurred in both urban and rural areas, as rainfall was reduced by more than 50%. This decrease in rainfall affects most especially the urban poor as they experience acutely the dwindling supply of potable water, increasing costs of water, and compromised access to hygiene and sanitation services. Consequently, droughts have become a major concern for risk governance in major urban centers. Science-informed and contextually driven local climate adaptation plans (LCAP) seem to be the most appropriate response to mitigate and adapt to the effects of drought brought about by El Nino.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.5373/JARDCS/V11SP11/20193132", "year": 2019, "title": "A New Agricultural Drought Index to Better Detect and Monitor Millet Crop by Remote Sensing in West Africa: Case of Niger", "abstract": "In this paper, we propose to establish a remote sensing-based agricultural drought indicator named Agricultural Drought Condition Index (ADCI) that will detect agricultural drought linked mainly to millet crops in the agricultural area of Niger. It is obtained by combining four key parameters: Precipitation Condition index (PCI), Evapotranspiration Condition Index (ETCI), Vegetation Condition Index (VCI) and Temperature Condition Index (TCI). PCI is used to reflect precipitation deficit (Du et al., 2013), VCI is used to reflect variations in the health status of vegetation, TCI is used to identify vegetation stress produced by high temperatures or excessive humidity and ETCI is used to reflect crop shortage. ADCI is calculated over the crop growth period (June to October) from 2003 to 2017 in the agricultural area of Niger. Then, a comparison analysis between the ADCI results and the millet crop yield was carried out. Based on these results, ADCI shows a very statistically significant correlation with the millet crop yield throughout the millet growth period (June-October) and it is strongly correlated with the VHI index but provided better drought conditions then VHI. This new index is quite powerful and capable to identify and monitor the agricultural drought related to the cultivation of millet.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.3390/W12061738", "year": 2020, "title": "Drought risk assessment in cultivated areas of central asia using MODIS time-series data", "abstract": "Drought is one of the most damaging environmental hazards and a naturally occurring phenomenon in Central Asia that is accompanied by crucial consequences for the agriculture sector. This research aimed at understanding the nature and extent of drought over the cropland regions of Central Asia with the help of spatiotemporal information from the region. We assessed drought occurrence using the vegetation health index (VHI). An algorithm was developed to reduce the noise of heterogeneous land surfaces by adjusting the vegetation index and brightness temperature. The vegetation condition index (VCI) and temperature condition index (TCI) were calculated using Moderate Resolution Imaging Spectroradiometer (MODIS) products for the growing season (AprilSeptember) from 2000 to 2015. The intense drought years were identified and a drought map (drought probability occurrence) was generated. The findings of this research indicated regional heterogeneity in the cropland areas having experienced droughts, observed through spatiotemporal variations. Some of the rain-fed and irrigated croplands of Kazakhstan demonstrated a higher vulnerability to annual drought occurrences and climate change impacts, while other cropland regions were found to be more resistant to such changes. The development of policy tools is required to support informed decision-making and planning processes to adapt to the occurrence of droughts. This could be achieved by the timely assessment, monitoring, and evaluation of the spatiotemporal distribution trends and variabilities of drought occurrences in this region. The results from this study focus on the spatiotemporal variations in drought to reveal the bigger picture in order to better understand the regional capacity for sustainable land management and agricultural activities within a changing environment.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.JENVMAN.2021.112028", "year": 2021, "title": "Drought disaster monitoring using MODIS derived index for drought years: A space-based information for ecosystems and environmental conservation", "abstract": "Drought disaster is one of the major factors restricting the development of vegetation across a wide variety of environments. Monitoring the temporal and spatial dynamics of drought episodes in the study area is crucial for environmental and ecosystem conservation. This study assesses drought disaster by utilising space-based data and R programming for drought years 2003, 2007, 2012 and 2019 in the Free State Province, South Africa. Results revealed that the study area witnessed drought events in the year 2003 where March, August, September, October, November and December were more affected by drought disaster events. It was further observed that February and March were affected by extreme drought conditions in the year 2007. In year 2012, January, October, November and December, there exist moderate to severe drought conditions in the study area where some regions were more affected than the other. Finally, year 2019 witnessed variations in drought event distributions across the months with January, October and November witnessing severe to extreme drought conditions from about 0 to 30% drought values. Overall, this study shows that the 16-day Terra-MODIS composite and EVI products are sensitive to stressors associated with drought. The Vegetation Condition Monitoring Index (VCI) based on MODIS is suited for monitoring drought disasters. The technique used in this study revealed the suitability of MODIS data for assessing drought conditions and their potential environmental impacts.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1002/RSE2.229", "year": 2022, "title": "Bidirectional drought-related canopy dynamics across pantropical", "abstract": "Droughts cause extreme anomalies in tropical forest growth, but the direction and magnitude of tropical forests in response to droughts are still widely debated. Here, we used four satellite\u2011based canopy growth proxies (CGPs), including three optical and one passive microwave, and in situ fluxes observations from eddy covariance (EC) measurements for a retrospective investigation of the impacts of historical droughts on tropical forest growth from a statistical point of view. Results indicate two opposite directions in drought\u2011related canopy dynamics across pantropical forests. The canopy of tropical forests with higher CGPs is more vulnerable to drought stress and recovers faster in the post\u2011drought recovery period. In contrast, the canopy of tropical forests with lower CGPs increases during the drought period and declines in the subsequent recovery period, which is beyond general expectation. In situ measurements from eddy\u2011covariance flux towers showed that forests with higher gross primary production and latent heat flux decreased photosynthesis and evapotranspiration during the drought period but increased photosynthesis and evapotranspiration faster during the post\u2011drought recovery period, supporting the findings from satellite observations. Our statistical analysis against climatic factors predicts that higher\u2011CGPs tress with probably taller and bigger canopies are more responsive to shortage of water availability caused by drought; while lower\u2011CGPs tress with shorter and smaller canopies are more responsive to sunlight availability and tend to increase their canopy leaves and enhance photosynthesis in sunnier days during the drought period. Our results highlight the differences in tropical forests in responding to drought stress, which are worth incorporated in Earth system models for time\u2011series evaluations.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1088/1748-9326/ABEB35", "year": 2021, "title": "Decadal variability modulates trends in concurrent heat and drought over global croplands", "abstract": "Abstract\r\n Extreme heat and drought often reduce the yields of important food crops around the world, putting stress on regional and global food security. The probability of concurrently hot and dry conditions, which can have compounding impacts on crops, has already increased in many regions of the globe. The evolution of these trends in coming decades could have important impacts on global food security. However, regional variation and the influence of natural climate variability on these trends remains an important gap in understanding future climate risk to crops. In this study, we examine trends in concurrent hot-and-dry extremes over global maize and wheat croplands since 1950. We find that the mean extent of cropland in a joint hot-and-dry extreme increased by 2% over 19502009, and this trend has accelerated substantially since the mid-2000s, notably in the tropics. While joint hot-and-dry seasons affected at most 1%2% of global cropland per year during the mid-20th century, they regularly exceeded this extent after about 1980, affecting up to 5% of global crop area. These results suggest that the global climate is transitioning from one in which concurrent heat and drought occur rarely to one in which they occur over an important fraction of croplands every year. While these long-term global trends are primarily attributable to anthropogenic climate change, we find they have been suppressed by decadal climate variability in some regions, especially ones with chronic food insecurity. Potential reversals in these tendencies of decadal variability would accelerate exposure of croplands to concurrent heat and drought in coming decades. We conclude by highlighting the need for research and adaptive interventions around multivariate hazards to global crops across timescales.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.AGWAT.2022.107468", "year": 2022, "title": "Spatiotemporal patterns of water consumption and irrigation requirements of wheat-maize in the Huang-Huai-Hai Plain, China and options of their reduction", "abstract": "Severe water shortages threaten the sustainability of agriculture in the Huang-Huai-Hai Plain (3HP), China. This study investigated spatiotemporal variations in crop water consumption (evapotranspiration, ET) and irrigation water requirements (IWR) under existing winter wheatsummer maize (WWSM) cropping system in the 3HP, and tested alternatives of their reduction that may require less irrigation, i.e., wheatmaizewheatfallow (WMWF), wheatmaizefallowmaize (WMFM), wheatmaizefallowspring maize (WMFSM), and fallowspring maizefallowspring maize (FSMFSM). The results showed that the annual ET indicated no significant change from 2001 to 2018, which decreased from southeast to northwest and ranged from 700 mm to 900 mm. In the winter wheat (WW) season, ET increased significantly at the junction of Hebei and Shandong provinces, while it decreased in western Hebei during the summer maize (SM) period. Moreover, ET for WW decreased from dry to normal and wet years (433, 413, and 373, mm), while it increased in SM season (377, 392, and 396, mm). IWR showed great interannual variability. Anhui, central and southern Henan, and southwestern Shandong presented annual IWR below 200 mm, with 100300 mm in the WW period, and 300 (0) 100 mm in the SM period (negative IWR means rainfall surplus and no real irrigation). The north of the 3HP required considerable irrigation in the WW season, especially in western Hebei and northwestern Shandong (over 300 mm in dry years and 200 mm in wet years), with IWR ranging from 100100 mm in the SM period. The 18-year average IWR of WWSM, WMWF, WMFM, WMFSM, and FSMFSM was 344, 321, 211, 240, and 119 mm, respectively, from 2001 to 2018 (Luancheng as example, same below). Reducing irrigation by 32%, 44%, and 64%, WMFSM, WMFM and FSMFSM showed the greatest potential for reducing IWR, but food security should also be considered when adjustments are made.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.JHYDROL.2021.127396", "year": 2021, "title": "Relative effect of anthropogenic warming and natural climate variability to changes in Compound drought and heatwaves", "abstract": "Compound drought and heatwave (CDHW) events can be influenced by large scale teleconnections and anthropogenic warming, leading to severe socio-economic impacts across various climate regions. In this study, the relative influence of six different teleconnection patterns and anthropogenic global warming on the global CDHW occurrences is quantified systematically using the instrumental data period, 19822016. The results from the study suggest a substantial increase in the CDHW events (15 events per year) across various parts of the globe at the beginning of 21st century (20002016). A Bayesian approach is implemented to identify the most vulnerable climate regions based on the degree of susceptibility of heatwaves (DSHW) towards drought. As such, top ten most vulnerable regions are selected based on the DSHW magnitude, and a partial correlation analysis is performed to select the natural and anthropogenic drivers of CDHW in those regions, separately. A logistic regression model is then used to determine significant changes in the odds of CDHW due to changes in the selected drivers that suggest a significantly positive, and multiplicative effect of anthropogenic global warming in the top ten most vulnerable climate regions. Finally, the same logistic regression model, integrated with an analytical framework, is applied to determine the relative influence of anthropogenic global warming on the changes in odds of CDHW for the future, 1.5 C and 2 C warming limits. The results suggest that relative to the 2 C global warming, constraining to the 1.5 C global warming limit may conduce about 17-fold reduction in the odds of CDHW in the most vulnerable climate region, East Asia, 58-fold reduction in Western North America, Northern Australia, Central North America, Central Europe, South Asia, and the Mediterranean region, and 34-fold reduction in Northeastern Brazil, Eastern North America, and West Asia.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 12, "name": "Heat" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1175/JCLI-D-19-0082.1", "year": 2020, "title": "Long-lead predictions of warm season droughts in South Korea using North Atlantic SST", "abstract": "Abstract Understanding and predicting warm season (MayOctober) droughts is critically important in South Korea for agricultural productivity and water resource management. Using a 6-month standardized precipitation index ending in October (SPI6_Oct), we investigate the interannual variability of warm season droughts and the related large-scale atmospheric circulations for the most recent 20-yr period (19952014). Cyclonic (anticyclonic) circulations to the east of Japan (in the North Pacific) tend to induce warm season droughts (wetness) by suppressing (enhancing) moist water transport from the south of the Korean Peninsula. These circulation patterns to the east of Japan are linked to a barotropic Rossby wavelike teleconnection pattern from the North Atlantic to East Asia, which is found to be responsible for the interannual variability of SPI6_Oct. This teleconnection pattern is highly correlated with the difference in sea surface temperature (SST) between the Norwegian Sea and the Barents Sea (referred to as NA_dipole) in JanuaryMarch (r = 0.68), which modulates the snow depth over the Ural Mountains in spring and the sea ice concentration over the Barents Sea during the entire warm season. Two drought prediction models, an empirical model and a hybrid machine learning model, are developed and tested for their predictive skills for South Korea. An empirical prediction model using NA_dipole as one of the predictors is found to accurately capture the interannual variability of SPI6_Oct (r2 = 53%). NA_dipole is found to improve the predictive skills of the hybrid machine learning drought prediction model, especially for longer lead times. Our results emphasize the significant role of North Atlantic SST anomalies in warm season medium-range droughts in South Korea.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.JHYDROL.2021.126638", "year": 2021, "title": "Integrated meteorological drought monitoring framework using multi-sensor and multi-temporal earth observation datasets and machine learning algorithms: A case \u2026", "abstract": "Devising strategies for drought planning and risk mitigation in predominantly small holder agriculture regions like South Asia requires improved understanding of spatio-temporal characteristics of droughts at finer spatial scales. In this study, an integrated framework is developed to generate high-resolution gridded precipitation products from publicly available coarse scale data, and use the downscaled products for analysis of meteorological droughts. Data from a region in Central India is used to develop and test the framework. The Standard Precipitation Index (SPI) is used to characterize meteorological drought. The proposed framework incorporates: (i) a Random Forest machine learning algorithm to downscale CHIRPS (5 km) gridded long term rainfall data to a higher resolution gridded product (1 km) using high resolution multi-sensor and multi-temporal earth observation data of land surface characteristics (vegetation, temperature, and topography) as cofactors; (ii) Computation of 3-month SPI (SPI-3) for the downscaled gridded rainfall; (iii) Run theory applied to downscaled SPI grid to determine drought characteristics - duration, severity, intensity, frequency, and onset and cessation of droughts, and (iv) Principal Components Analysis (PCA) to combine effects of multiple drought characteristics into a single composite Effective Meteorological Drought Index (EMDI), to identify sub-regional drought patterns. The downscaled gridded precipitation product (1 km) was validated using: (i) original CHIRPS (5 km) data, and (ii) measured rainfall data from 65 rain gauge stations in the study area, with respect to conservation of both statistical properties and spatial structure. Comparisons were also made with drought characteristics obtained from Standardized Evapotranspiration Index (SPEI) derived from MODIS evapotranspiration data. The downscaled product captures spatio-temporal variability of droughts at finer village and sub-village scales, compared to original CHIRPS (5 km) data for which each pixel encompassed multiple villages. Spatial distribution of composite index EMDI delineates the study area into two characteristic drought risk regions. In one region, droughts are of longer duration, but are less frequent, with lower severity and intensity. In the second region droughts are of shorter duration but of higher severity, intensity and frequency. The integrated framework developed in this study for high resolution spatio-temporal analysis of droughts, starting from coarse scale precipitation data, is practical and sufficiently general to adopt in other regions to support local drought risk planning and targeting mitigation decisions and actions.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1111/NPH.15110", "year": 2018, "title": "El Nino drought increased canopy turnover in Amazon forests", "abstract": "Summary Amazon droughts, including the 20152016 El Nino, may reduce forest net primary productivity and increase canopy tree mortality, thereby altering both the short and the longterm net forest carbon balance. Given the broad extent of drought impacts, inventory plots or eddy flux towers may not capture regional variability in forest response to drought. We used multitemporal airborne Lidar data and field measurements of coarse woody debris to estimate patterns of canopy turnover and associated carbon losses in intact and fragmented forests in the central Brazilian Amazon between 20132014 and 20142016. Average annualized canopy turnover rates increased by 65% during the drought period in both intact and fragmented forests. The average size and height of turnover events was similar for both time intervals, in contrast to expectations that the 20152016 El Nino drought would disproportionally affect large trees. Lidarbiomass relationships between canopy turnover and field measurements of coarse woody debris were modest (R2 0.3), given similar coarse woody debris production and Lidarderived changes in canopy volume from single tree and multiple branch fall events. Our findings suggest that El Nino conditions accelerated canopy turnover in central Amazon forests, increasing coarse woody debris production by 62% to 1.22 Mg C ha1 yr1 in drought years . ", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1007/S00382-019-04638-Y", "year": 2019, "title": "Precursors of quasi-decadal dry-spells in the Central America Dry Corridor", "abstract": "Although the hydric stress in Central America is generally low, there is a region relatively drier and prone to drought known as the Central America Dry Corridor (CADC). The area of interest is located mainly in the Pacific slope of Central America, from Chiapas in southern Mexico, to the Nicoya Peninsula in the Costa Rican North Pacific. Most of the region has experienced significant warming trends (19701999). On the contrary precipitation and the Palmer Drought Severity Index (PDSI) have mainly displayed non-significant trends. Analysis using the Standardized Precipitation Index and PDSI in the CADC, suggests a significant periodicity of severe and sustained droughts of around 10 years. The drought response has been associated with tropical heating that drives an atmospheric response through strengthening of the Hadley cell, which in turn produces higher pressure in the subtropical highs, and intensification of the trade winds (indexed by the Caribbean Low Level Jet). It is important to determine the commonness of severe and sustained droughts in the CADC to improve water resources planning, as this is a region that depends on subsistence agriculture and presents high social and economic vulnerabilities.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.WORLDDEV.2018.11.002", "year": 2019, "title": "Water as destiny\u2013The long-term impacts of drought in sub-Saharan Africa", "abstract": "We examine the long-term impacts of drought exposure on women born in 19 countries in sub-Saharan Africa, across four decades. We find that women who were exposed to drought conditions during their early childhood are significantly less wealthy as adults. These effects are confined to women born and raised in rural households, indicating that the impacts of rainfall are felt via changes in agricultural output. In addition to lower levels of wealth, women who experience droughts in infancy also receive fewer years of formal education and, in the case of extreme drought conditions, have reduced adult heights. Our results also suggest that drought exposure in infancy can have long-term, negative impacts on womens empowerment. Finally, we also show that these impacts may be transmitted to the womens offspring, with children of affected women more likely to be born at a low birth weight (weighing <2.5 kg). To our knowledge, this represents the largest study to date both geographically and over time showing a strong relationship between early life rainfall conditions and adult outcomes, and the first to show that the impacts could span generations.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/BG-11-2897-2014", "year": 2014, "title": "Response of vegetation to the 2003 European drought was mitigated by height", "abstract": "Abstract. The effects on climate of land-cover change, predominantly from the conversion of forests to crops or grassland, are reasonably well understood for low and high latitudes but are largely unknown for temperate latitudes. The main reason for this gap in our knowledge is that there are compensating effects on the energy and water balance that are related to changes in land-surface albedo, soil evaporation and plant transpiration. We analyse how vegetation height affected the response of vegetation during the 2003 European drought using precipitation data, temperature data, normalized difference vegetation index data and a new vegetation height data set obtained from the Geoscience Laser Altimeter System (GLAS) on the Ice, Cloud and land Elevation Satellite (ICESat). At the height of the 2003 drought we find for tall vegetation a significantly smaller decrease in vegetation index and a smaller diurnal temperature (DTR) range, indicating less water stress and drought impacts on tall vegetation. Over Germany for example, 98% of significant correlations showed a smaller anomaly in vegetation index anomaly with greater height, and 95% of significant correlations showed a smaller DTR with greater vegetation height. Over France the equivalent percentages were 94 and 88%, respectively. Vegetation height is likely associated with greater rooting depth, canopy heat capacity or both. Our results suggest that land-surface models can be improved by better estimates of vegetation height and associated with this a more realistic response to drought.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.JHYDROL.2018.11.058", "year": 2018, "title": "Enhancing the standardized drought vulnerability index by integrating spatiotemporal information from satellite and in situ data", "abstract": "Drought is a complex natural hazard with its adverse multifaceted impacts cascading in every physical and human system. The vulnerability magnitude of various areas to drought mostly depends on their exposure to water deficiency, the existing water management policy framework and its implementation. The Standardized Drought Vulnerability Index (SDVI) is an integrated attempt towards characterizing drought vulnerability based on a comparative classification system, incorporating precipitation patterns, the supply and demand trends, and the socioeconomic background as the most crucial contributors to drought vulnerability. This work attempts to evolve the SDVI by presenting a more rigorous method of index parameters estimation and argues that the combination of in-situ and satellite data improve the index results in an effort to further minimize the paucity of drought related information. At the same time, it helps to surpass previous limitations in temporal and spatial propagation of the vulnerability concept. The new framework is applied in the South Platte Basin, within Colorado, on the 2012 summer drought (July-September). The proposed index modification may convey drought information in a more holistic manner to decision makers. SDVI could aid in advancing the understanding of each component contribution through in situ and remote sensing data integration and in avoiding existing practices of broken linkages and fragmentation of the reported impacts. Thus, it is believed that the SDVI could serve as an additional tool to guide decisions and target mitigation and adaptation actions, allowing for a more integrated management approach.", "labels": [ { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1029/2022GL099265", "year": 2022, "title": "Cascading DroughtHeat Dynamics During the 2021 Southwest United States Heatwave", "abstract": "In June of 2021 the Southwest United States experienced a record-breaking heatwave. This heatwave came at a time when the region was in severe drought. As drought alters the surface energy budget in ways that affect lower atmosphere temperature and circulations, it is possible that the combined drought-heat event was a cascading climate hazard, in which preexisting drought exacerbated the heatwave. We apply satellite observation and numerical experiments with the Weather Research and Forecasting (WRF) model to test for land-atmosphere feedbacks during the heatwave consistent with drought influence. We find a modest positive drought-heat effect, as WRF simulations that include the drought have marginally higher air temperatures than those that exclude the initial drought conditions, with more substantial effects in wetter, forested areas. Evidence of drought-heat-drought-coupled feedbacks was similarly modest in our simulations, as accounting for drought preconditioning led to a small reduction in simulated precipitation in the region.", "labels": [ { "id": 4, "name": "Droughts" }, { "id": 12, "name": "Heat" } ] }, { "doi": "10.5194/NHESS-18-1665-2018", "year": 2018, "title": "Earthquakes on the surface: earthquake location and area based on more than 14 500 ShakeMaps", "abstract": "Abstract. Earthquake impact is an inherently interdisciplinary topic that receives attention from many disciplines. The natural hazard of strong ground motion is the reason why earthquakes are of interest to more than just seismologists. However, earthquake shaking data often receive too little attention by the general public and impact research in the social sciences. The vocabulary used to discuss earthquakes has mostly evolved within and for the discipline of seismology. Discussions on earthquakes outside of seismology thus often use suboptimal concepts that are not of primary concern. This study provides new theoretic concepts as well as novel quantitative data analysis based on shaking data. A dataset of relevant global earthquake ground shaking from 1960 to 2016 based on USGS ShakeMap data has been constructed and applied to the determination of past ground shaking worldwide. Two new definitions of earthquake location (the shaking center and the shaking centroid) based on ground motion parameters are introduced and compared to the epicenter. These definitions are intended to facilitate a translation of the concept of earthquake location from a seismology context to a geographic context. Furthermore, the first global quantitative analysis on the size of the area that is on average exposed to strong ground motion measured by peak ground acceleration (PGA) is provided.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.6038/CJG2022P0732", "year": 2022, "title": "Using space observation techniques to study temporal and spatial characteristics of seismogenic process, occurrence and deformation of the Qinghai Madoi MW7.4 \u2026", "abstract": "In order to reveal the characteristics of pre-seismic deformation and co-seismic rupture of the 2021 Qinghai Madoi MW7.4 earthquake, we systematically collect the GNSS data from Qinghai CORS and Crustal Movement Observation Network of China and the SAR data from Sentinel-1 and ALOS-2 satellites, and obtain the dynamic deformation field of the Madoi earthquake by the integrated processing of multi-source data. The pre-seismic GNSS deformation field shows that the Madoi focal area is located at the edge of the high-value region of shear deformation in the north of the earthquake, and sinistral shear strain was accumulated there before the earthquake. The 3-D co-seismic deformation field shows that the KunlunshanPass-Jiangcuo fault has a significant sinistral rupture, and the co-seismic deformation mainly occurs within 100 km from the fault with a maximum horizontal component of 2.4 m. The vertical co-seismic deformation mainly occurs in the vicinity of the fault, and shows alternately positive and negative variation from one side of the fault to the other, which reveals the spatial diversity of dip angles of the ruptured fault. The result of the joint inversion of GNSS and InSAR shows that the rupture of the Madoi earthquake reaches the surface, which is mainly distributed above 15 km depth, with the maximum slip value at about 4 m, and the moment magnitude is about 7.4. The rupture along the fault strike shows an obvious segmental characteristic, and five regions with significant slip values are distributed discontinuously.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0120190191", "year": 2020, "title": "Constraining Properties of Sedimentary Strata Using Receiver Functions: An Example from the Atlantic Coastal Plain of the Southeastern United States", "abstract": "Thickness and seismic velocities of sedimentary sequences strongly affect their response during earthquakes, which can prolong and amplify ground motions. We characterize shallow structure of Atlantic Coastal Plain (ACP) sediments using a passiveseismic approach based on highfrequency PtoS receiver functions. We map the sitespecific fundamental frequency for 64 USArray Transportable Array stations and confirm that the method yields results similar to those from traditional spectral ratio techniques, with fundamental frequencies between 0.1 and 1 Hz. In addition, using sediment Swave reverberations and PtoS phase arrival times measured directly from the receiver functions, we invert for average S and Pwave velocity profiles of the ACP sedimentary strata. We find that VS increases with depth following a powerlaw relationship (VSz) whereas the increase of VP with depth is more difficult to constrain using converted wave methods; therefore, we choose to use the Brocher (2005) relationship to obtain VP through a VP/VS relationship. Finally, we use the variation of measured Sreverberation amplitudes with depth to validate these velocity profiles. These results have implications for seismic shaking across the ACP, which covers large portions of the eastern United States.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0120200021", "year": 2020, "title": "Real\u2010Time Performance of the PLUM Earthquake Early Warning Method during the 2019 6.4 and 7.1 Ridgecrest, California, Earthquakes", "abstract": "We evaluate the timeliness and accuracy of groundmotionbased earthquake early warning (EEW) during the July 2019 M 6.4 and 7.1 Ridgecrest earthquakes. In 2018, we began retrospective and internal realtime testing of the propagation of local undamped motion (PLUM) method for earthquake warning in California, Oregon, and Washington, with the potential that PLUM might one day be included in the ShakeAlert EEW system. A realtime version of PLUM was running on one of the ShakeAlert EEW systems development servers at the time of the 2019 Ridgecrest sequence, allowing us to evaluate the timeliness and accuracy of PLUMs warnings for the M 6.4 and 7.1 mainshocks in real time with the actual data availability and latencies of the operational ShakeAlert EEW system. The latter is especially important because highdata latencies during the M 7.1 earthquake degraded ShakeAlerts performance. PLUM proved to be largely immune to these latencies. In this article, we present a retrospective analysis of PLUM performance and explore three potential regional alerting strategies ranging from spatially large regions (counties), to moderatesize regions (National Weather Service public forecast zones), to highspatial specificity (50 km regular geographic grid). PLUM generated initial shaking forecasts for the two mainshocks 5 and 6 s after their respective origin times, and faster than the ShakeAlert systems first alerts. PLUM was also able to accurately forecast shaking across southern California for all three alerting strategies studied. As would be expected, a costbenefit analysis of each approach illustrates tradeoffs between increasing warning time and minimizing the area receiving unneeded alerts. Choosing an optimal alerting strategy requires knowledge of users false alarm tolerance and minimum required warning time for taking protective action, as well as the time required to distribute alerts to users.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1016/J.JAESX.2022.100096", "year": 2022, "title": "Consecutive statistical evaluation framework for earthquake forecasting: Evaluating satellite surface temperature anomaly detection methods", "abstract": "Short-term earthquake prediction remains a challenge. In this study, we investigated earthquake predictability using a consecutive statistical evaluation framework (CSEF). Two widely used anomaly detection methodsZ-score (ZS) and Robust Satellite Techniques (RST)were evaluated using the Atmospheric Infrared Sounder surface temperature data based on global M 6 earthquakes with focal depths of 70 km from 2006 to 2020. Retrospective correlation analyses reveal accuracy and missed detection rates of 80.33% & 19.67% and 80.93% & 19.67% for ZS and RST, respectively. For earthquake forecasting performance in seismically active regions, accuracy rates are within 01% and false alarm rates are up to 5080%. Areas near earthquake-prone regions have the highest accuracy rates. The accuracy rates can be >10% within some regions in Japan and Indonesia. Overall temporal average Matthews correlation coefficients (MCC) range from 0.48 to 0.21; global spatial average MCCs for each day from 2006 to 2020 are between 0.1 and 0.1. After 2012, the ZS method yields higher MCC values than the RST method. Our results confirm the reliability of CESF for assessment of earthquake forecasting capability, and the possibility of forecasting earthquakes at earthquake-prone areas. This approach can be applied to long-term analyses of precursory parameters, anomaly detection methods, and hypotheses, all of which are essential to the ultimate goal of routine and consistent earthquake forecasting.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1177/8755293021989333", "year": 2021, "title": "Exposure forecasting for seismic risk estimation: Application to Costa Rica", "abstract": "This study proposes a framework to forecast the spatial distribution of population and residential buildings for the assessment of future disaster risk. The approach accounts for the number, location, and characteristics of future assets considering sources of aleatory and epistemic uncertainty in several time-dependent variables. The value of the methodology is demonstrated at the urban scale using an earthquake scenario for the Great Metropolitan Area of Costa Rica. Hundreds of trajectories representing future urban growth were generated using geographically weighted regression and multiple-agent systems. These were converted into exposure models featuring the spatial correlation of urban expansion and the densification of the built environment. The forecasted earthquake losses indicate a mean increase in the absolute human and economic losses by 2030. However, the trajectory of relative risk is reducing, suggesting that the long-term enforcement of seismic regulations and urban planning are effectively lowering seismic risk in the case of Costa Rica.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1785/0220180228", "year": 2019, "title": "Insights into seismogenic deformation during the 2018 Hualien, Taiwan, earthquake sequence from InSAR, GPS, and modeling", "abstract": "We provide new data and insights into a 6 February 2018 Mw 6.4 earthquake that shook the city of Hualien in eastern Taiwan at the leading edge of a modern arccontinent collision. Fatalities and damages were concentrated near the Milun fault and extended south to the northern Longitudinal Valley fault. Although the Hualien area has one of the highest rates of seismicity in Taiwan, the geologic structures responsible for active deformation were not well understood before this event. We analyzed Interferometric Synthetic Aperture Radar (InSAR) and Global Positioning System (GPS) data and produced a 3D displacement model with InSAR and azimuth offset of radar images to document surface deformation induced by this earthquake. The 3D displacement model was inverted to estimate slip on the Milun fault. We find that models assuming a single fault are inconsistent with observations of coseismic deformation and regional strain patterns, providing evidence for linked slip on a littlestudied offshore thrust belt. Based on data presented here and elsewhere, we propose a model for transpressive deformation in a zone of oblique convergence and leftlateral wrench tectonics to explain this and a prior 1951 M 7.3 earthquake.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1111/CGF.14311", "year": 2021, "title": "Visual Analysis of Spatiotemporal Phenomena with 1D Projections", "abstract": "AbstractIt is crucial to visually extrapolate the characteristics of their evolution to understand critical spatiotemporal events such as earthquakes, fires, or the spreading of a disease. Animations embedded in the spatial context can be helpful for understanding details, but have proven to be less effective for overview and comparison tasks. We present an interactive approach for the exploration of spatiotemporal data, based on a set of neighborhoodpreserving 1D projections which help identify patterns and support the comparison of numerous time steps and multivariate data. An important objective of the proposed approach is the visual description of local neighborhoods in the 1D projection to reveal patterns of similarity and propagation. As this locality cannot generally be guaranteed, we provide a selection of different projection techniques, as well as a hierarchical approach, to support the analysis of different data characteristics. In addition, we offer an interactive exploration technique to reorganize and improve the mapping locally to users' foci of interest. We demonstrate the usefulness of our approach with different realworld application scenarios and discuss the feedback we received from domain and visualization experts.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1186/S40623-017-0753-9", "year": 2017, "title": "Possible correlation between annual gravity change and shallow background seismicity rate at subduction zone by surface load", "abstract": "The Gravity Recovery and Climate Experiment (GRACE) has monitored global gravity changes since 2002. Gravity changes are considered to represent hydrological water mass movements around the surface of the globe, although fault slip of a large earthquake also causes perturbation of gravity. Since surface water movements are expected to affect earthquake occurrences via elastic surface load or pore-fluid pressure increase, correlation between gravity changes and occurrences of small (not large) earthquakes may reflect the effects of surface water movements. In the present study, we focus on earthquakes smaller than magnitude 7.5 and examine the relation between annual gravity changes and earthquake occurrences at worldwide subduction zones. First, we extract amplitudes of annual gravity changes from GRACE data for land. Next, we estimate background seismicity rates in the epidemic-type aftershock sequence model from shallow seismicity data having magnitudes of over 4.5. Then, we perform correlation analysis of the amplitudes of the annual gravity changes and the shallow background seismicity rates, excluding source areas of large earthquakes, and find moderate positive correlation. It implies that annual water movements can activate shallow earthquakes, although the surface load elastostatic stress changes are on the order of or below 1 kPa, as small as a regional case in a previous study. We speculate that periodic stress perturbation is amplified through nonlinear responses of frictional faults.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JB021830", "year": 2021, "title": "From Interseismic Deformation With Near\u2010Repeating Earthquakes to Co\u2010Seismic Rupture: A Unified View of the 2020 Mw6.8 Sivrice (Elaz\u0131\u011f) Eastern Turkey \u2026", "abstract": "The East Anatolian Fault (EAF) is a left-lateral transform fault accommodating the relative motion between the Anatolian and Arabian plates. On January 24, 2020, Mw6.8 Sivrice (Elaz\u0131\u011f) earthquake is the largest event that occurred along the EAF since the nineteenth century. The earthquake provides a unique opportunity to capture a critical stage of the seismic cycle from the interseismic deformation to co-seismic rupture. In this study, we examine the relationship between the interseismic fault activity and co-seismic behavior of the earthquake. A kinematic model of the earthquake obtained from strong-motion, GNSS and teleseismic waveforms along with static displacements from GNSS and InSAR data shows that the mainshock ruptured only 45 km of the 95 km long Sivrice-P\u00fct\u00fcrge segment. Rupture initiated adjacent to the interseismically weakly coupled northeastern section and propagated unilaterally toward southwest with a rupture velocity of \u223c2.5 km/s, stopping \u223c30 km before the southwestern segment boundary. The earthquake did not generate any surface offsets. We identified 4 long-term near-repeating earthquake clusters beneath the highest co-seismic slip zone adjacent to the northeastern creeping section. The mainshock was dynamically triggered by a M \u223c 5.4 foreshock located within the zone of near-repeating earthquakes. We suggest that creep along the weakly coupled section of the fault loaded the neighboring locked section leading to the repeating earthquakes below the locked zone. The earthquake partially ruptured a fault segment characterized by high rate of diffuse seismicity, structural complexities and heterogeneous coupling, leading to a source characterized by a complex source time function with relatively slow rupture velocity.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1038/S41598-022-08671-6", "year": 2022, "title": "Irregular rupture propagation and geometric fault complexities during the 2010 Mw 7.2 El Mayor-Cucapah earthquake", "abstract": "The 2010 MW 7.2 El Mayor-Cucapah, Mexico, earthquake ruptured multiple faults with different faulting mechanisms. Resolving the earthquake rupture process and its relation to the geometric fault complexities is critical to our understanding of the earthquake source physics, but doing so by conventional finite-fault inversion is challenging because modelling errors due to inappropriate assumptions about the fault geometry distort the solution and make robust interpretation difficult. Here, using a potency density tensor approach to finite-fault inversion, we inverted the observed teleseismic P waveforms of the 2010 El Mayor-Cucapah earthquake to simultaneously estimate the rupture process and the fault geometry. We found that the earthquake consisted of an initial normal faulting rupture, which was followed by a strike-slip bilateral rupture towards the southeast and northwest that originated on the northwest side of the epicentre. The southeastern rupture propagated back through the initial rupture area, but with strike-slip faulting. Although the northwestern rupture propagated across the left step in the Puerta fault-accommodation zone, the rupture was temporarily stalled by the associated change of the fault geometry. These results highlight the irregular rupture process, which involved a back-propagating rupture and fluctuating rupture propagation controlled the complexity of the fault system.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/GEOSCIENCES10090372", "year": 2020, "title": "A Review of Tsunami Hazards in the Makran Subduction Zone", "abstract": "The uncertain tsunamigenic potential of the Makran Subduction Zone (MSZ) has made it an interesting natural laboratory for tsunami-related studies. This study aims to review the recent activities on tsunami hazard in the Makran subduction zone with a focus on deterministic and probabilistic tsunami hazard assessments. While almost all studies focused on tsunami hazard from the Makran subduction thrust, other local sources such as splay faults and landslides can be also real threats in the future. Far-field tsunami sources such as Sumatra-Andaman and Java subduction zones, commonly lumped as the Sunda subduction zone, do not seem to pose a serious risk to the Makran coastlines. The tsunamigenic potential of the western segment of the MSZ should not be underestimated considering the new evidence from geological studies and lessons from past tsunamis in the world. An overview of the results of tsunami hazard studies shows that the coastal area between Kereti to Ormara along the shoreline of Iran-Pakistan and the coastal segment between Muscat and Sur along Omans shoreline are the most hazardous areas. Uncertainties in studying tsunami hazard for the Makran region are large. We recommend that future studies mainly focus on the role of thick sediments, a better understanding of the plates interface geometry, the source mechanism and history of extreme-wave deposits, the contribution of other local tsunamigenic sources and vulnerability assessment for all coastlines of the whole Makran region.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/RS14174375", "year": 2022, "title": "Application of Soil Moisture Active Passive (SMAP) Satellite Data in Seismic Response Assessment", "abstract": "The proven relationship between soil moisture and seismic ground response highlights the need for a tool to track the Earths surface soil moisture before and after seismic events. This paper introduces the application of Soil Moisture Active Passive (SMAP) satellite data for global soil moisture measurement during earthquakes and consequent events. An approach is presented to study areas that experienced high level of increase in soil moisture during eleven earthquakes. Two ancillary datasets, Global Precipitation Measurement (GPM) and Global Land Data Assimilation (GLDAS), were used to isolate areas that had an earthquake-induced increase in soil moisture from those that were due to hydrological processes. SMAP-based soil moisture changes were synthesized with seismic records developed by the United States Geological Survey (USGS), mapped ground failures in reconnaissance reports, and surface changes marked by Synthetic Aperture Radar (SAR)-based damage proxy maps. In the majority of the target earthquakes, including Croatia 2020, Greece 2020, Indonesia 2018, Taiwan 2016, Ecuador 2016, and Nepal 2015, a relationship between the SMAP soil moisture estimates and seismic events was evident. For these events, the earthquake-induced soil moisture response occurred in liquefaction-prone seismic zones. The New Zealand 2016 event was the only study region for which there was a clear inconsistency between SMSMAP and the seismic records. The promising relationship between soil moisture changes and ground deformations indicates that SMAP would be a useful data resource for geotechnical earthquake engineering applications and reconnaissance efforts.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2022GC010334", "year": 2022, "title": "Spatial Extent of Mid\u2010To Late\u2010Holocene Sedimentary Record of Tsunamis Along the Southern Kuril Trench, Hokkaido, Japan", "abstract": "With their complex cycles and rupture modes, infrequent megathrust earthquakes require a high-resolution spatiotemporal record of tsunami inundations over thousands of years to provide more accurate long-term forecasts. The geological record suggests that Mw > 8 earthquakes in the Kuril Trench occurred at intervals of several hundred years. However, uncertainties remain regarding the rupture zone, owing to the limited survey areas and chronological data. Therefore, we investigated the tsunami deposits in a coastal wetland of southeastern Hokkaido, Japan, to characterize the tsunamis that originated from the Kuril Trench over the last 4,000 years. On the Erimo coast, more than seven sand layers exhibited common features of tsunami deposits, such as sheet distributions of several hundred meters, normal grading structures, and sharp basal contacts. According to numerical tsunami simulations, the 17th-century sand layer could be reproduced using a multiple rupture zone model (Mw \u223c 8.8). We used high-resolution radiocarbon dating and tephras to correlate the tsunami deposits from the last 4,000 years with those reported from regions \u223c100 km away. The tsunami history revealed here shows good agreement with the histories of adjacent regions. However, the paleotsunamis reported to have occurred in regions >200 km away include events that differ from those in this study, suggesting a diversity of Mw > 8 earthquakes in the Kuril Trench. We clarified the history and extents of earthquake-generated tsunamis along the southwestern end of the Kuril Trench, which were previously unknown. Our results provide a framework for magnitude estimations and long-term forecasts of earthquakes.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S10518-021-01312-9", "year": 2022, "title": "Epistemic uncertainty of probabilistic building exposure compositions in scenario-based earthquake loss models", "abstract": "In seismic risk assessment, the sources of uncertainty associated with building exposure modelling have not received as much attention as other components related to hazard and vulnerability. Conventional practices such as assuming absolute portfolio compositions (i.e., proportions per building class) from expert-based assumptions over aggregated data crudely disregard the contribution of uncertainty of the exposure upon earthquake loss models. In this work, we introduce the concept that the degree of knowledge of a building stock can be described within a Bayesian probabilistic approach that integrates both expert-based prior distributions and data collection on individual buildings. We investigate the impact of the epistemic uncertainty in the portfolio composition on scenario-based earthquake loss models through an exposure-oriented logic tree arrangement based on synthetic building portfolios. For illustrative purposes, we consider the residential building stock of Valparaiso (Chile) subjected to seismic ground-shaking from one subduction earthquake. We have found that building class reconnaissance, either from prior assumptions by desktop studies with aggregated data (topdown approach), or from building-by-building data collection (bottomup approach), plays a fundamental role in the statistical modelling of exposure. To model the vulnerability of such a heterogeneous building stock, we require that their associated set of structural fragility functions handle multiple spectral periods. Thereby, we also discuss the relevance and specific uncertainty upon generating either uncorrelated or spatially cross-correlated ground motion fields within this framework. We successively show how various epistemic uncertainties embedded within these probabilistic exposure models are differently propagated throughout the computed direct financial losses. This work calls for further efforts to redesign desktop exposure studies, while also highlighting the importance of exposure data collection with standardized and iterative approaches.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1029/2021JB021915", "year": 2021, "title": "Effect of Merging Multiscale Models on Seismic Wavefield Predictions near the Southern San Andreas Fault", "abstract": "Updating Earth models used by the scientific community in geologic studies and hazard assessment has a significant societal impact but is computationally prohibitive due to the large spatial scale. The advent of urban seismology allowed rapid development of local high-resolution models using short-term dense seismic arrays to become conventional. To incorporate the details in these local models in community models, we developed a technique for constructing window taper functions like the cosine taper in arbitrarily shaped spatial domains on regular grids. We apply our algorithm to the problem of low-frequency ground shaking estimation near the southernmost San Andreas fault by creating two hybrid models. These models consist of basin-scale (top 10 km or less) high-resolution models developed using controlled source data embedded into two popular Southern California Earthquake Center community models. We evaluate the models by computing long period (6-30 s) wavefield energy misfits using 11 earthquakes with moment magnitudes between 3.5 and 5.5 not used in developing any of the models under consideration. One of the hybrid models produces an \u223c24% decrease while the other has an \u223c0.6% increase in the overall median misfit relative to their original community models. The overlapping misfit values between the models and variability in waveform fit for different events and stations emphasize the difficulties in model validation. Our approach can merge any type of gridded multiscale and multidimensional datasets, and represents a valuable tool for modeling in the computational sciences.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1007/S00024-016-1417-6", "year": 2016, "title": "Real-Time Earthquake Intensity Estimation Using Streaming Data Analysis", "abstract": "Earthquake intensity is one of the key components of the decision-making process for disaster response and emergency services. Accurate and rapid intensity calculations can help to reduce total loss and the number of casualties after an earthquake. Modern intensity assessment procedures handle a variety of information sources, which can be divided into two main categories. The first type of data is that derived from physical sensors, such as seismographs and accelerometers, while the second type consists of data obtained from social sensors, such as witness observations of the consequences of the earthquake itself. Estimation approaches using additional data sources or that combine sources from both data types tend to increase intensity uncertainty due to human factors and inadequate procedures for temporal and spatial estimation, resulting in precision errors in both time and space. Here we present a processing approach for the real-time analysis of streams of data from both source types. The physical sensor data is acquired from the U.S. Geological Survey (USGS) seismic network in California and the social sensor data is based on Twitter user observations. First, empirical relationships between tweet rate and observed Modified Mercalli Intensity (MMI) are developed using data from the M6.0 South Napa, CAF earthquake that occurred on August 24, 2014. Second, the streams of both data types are analyzed together in simulated real-time to produce one intensity map. The second implementation is based on IBM InfoSphere Streams, a cloud platform for real-time analytics of big data. To handle large processing workloads for data from various sources, it is deployed and run on a cloud-based cluster of virtual machines. We compare the quality and evolution of intensity maps from different data sources over 10-min time intervals immediately following the earthquake. Results from the joint analysis shows that it provides more complete coverage, with better accuracy and higher resolution over a larger area than either data source alone.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1126/SCIADV.ABI6031", "year": 2022, "title": "Bridging earthquakes and mountain building in the Santa Cruz Mountains, CA", "abstract": "Relative crustal motions along active faults generate earthquakes, and repeated earthquake cycles build mountain ranges over millions of years. However, the long-term summation of elastic, earthquake-related deformation cannot produce the deformation recorded within the rock record. Here, we provide an explanation for this discrepancy by showing that increases in strain facilitated by plastic deformation of Earths crust during the earthquake cycle, in conjunction with isostatic deflection and erosion, transform relative fault motions that produce individual earthquakes to geologic deformations. We focus our study on the data-rich Santa Cruz Mountains, CA, USA and compare predicted and observed quantities for rock uplift, apatite (U-Th)/He thermochronology, topographic relief,\r\n 10\r\n Be-based erosion rates, and interseismic surface velocities. This approach reconciles these disparate records of mountain-building processes, allowing us to explicitly bridge decadal measures of deformation with that produced by millions of years of plate motion.\r\n \r\n , \r\n Plastic yielding during predominantly elastic earthquake cycles reconciles disparate observations of crustal deformation.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1002/2017JB014341", "year": 2017, "title": "Piecemeal Rupture of the Mentawai Patch, Sumatra: The 2008Mw7.2 North Pagai Earthquake Sequence", "abstract": "The 25 February 2008 Mw 7.2 North Pagai earthquake partially ruptured the middle section of the Mentawai patch of the Sunda megathrust, offshore Sumatra. The patch has been forecast to generate a great earthquake in the next few decades. However, in the current cycle the patch has so far broken in a sequence of partial ruptures, one of which was the 2008 event, illustrating the potential of the patch to generate a spectrum of earthquake sizes. We estimate the coseismic slip distribution of the 2008 event by jointly inverting coseismic offsets from GPS and interferometric synthetic aperture radar. We then estimate afterslip with 5.6 years of cumulative GPS displacements. Our results suggest that the estimated afterslip partially overlaps the coseismic rupture. The overlap of coseismic rupture and afterslip can be explained conceptually by a simple rate-and-state model where the degree of overlapping is controlled by the dynamic weakening and the critical nucleation size in the velocity-weakening area. Comparing our rate-and-state model results with our geodetic inversion results, we suggest that the part of the coseismic rupture that does not overlap with the afterslip may represent a velocity-weakening region, while the overlapping part may represent a velocity-strengthening region.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.3390/IJGI11020113", "year": 2022, "title": "Towards a Sensitivity Analysis in Seismic Risk with Probabilistic Building Exposure Models: An Application in Valparaiso, Chile Using Ancillary Open-Source Data and Parametric Ground Motions", "abstract": "Efforts have been made in the past to enhance building exposure models on a regional scale with increasing spatial resolutions by integrating different data sources. This work follows a similar path and focuses on the downscaling of the existing SARA exposure model that was proposed for the residential building stock of the communes of Valparaiso and Vina del Mar (Chile). Although this model allowed great progress in harmonising building classes and characterising their differential physical vulnerabilities, it is now outdated, and in any case, it is spatially aggregated over large administrative units. Hence, to more accurately consider the impact of future earthquakes on these cities, it is necessary to employ more reliable exposure models. For such a purpose, we propose updating this existing model through a Bayesian approach by integrating ancillary data that has been made increasingly available from Volunteering Geo-Information (VGI) activities. Its spatial representation is also optimised in higher resolution aggregation units that avoid the inconvenience of having incomplete building-by-building footprints. A worst-case earthquake scenario is presented to calculate direct economic losses and highlight the degree of uncertainty imposed by exposure models in comparison with other parameters used to generate the seismic ground motions within a sensitivity analysis. This example study shows the great potential of using increasingly available VGI to update worldwide building exposure models as well as its importance in scenario-based seismic risk assessment.", "labels": [ { "id": 5, "name": "Earthquakes" } ] }, { "doi": "10.1371/JOURNAL.PONE.0209470", "year": 2018, "title": "Opportunities for natural infrastructure to improve urban water security in Latin America", "abstract": "Governments, development banks, corporations, and nonprofits are increasingly considering the potential contribution of watershed conservation activities to secure clean water for cities and to reduce flood risk. These organizations, however, often lack decision-relevant, initial screening information across multiple cities to identify which specific city-watershed combinations present not only water-related risks but also potentially attractive opportunities for mitigation via natural infrastructure approaches. To address this need, this paper presents a novel methodology for a continental assessment of the potential for watershed conservation activities to improve surface drinking water quality and mitigate riverine and stormwater flood risks in 70 major cities across Latin America. We used publicly available geospatial data to analyze 887 associated watersheds. Water quality metrics assessed the potential for agricultural practices, afforestation, riparian buffers, and forest conservation to mitigate sediment and phosphorus loads. Flood reduction metrics analyzed the role of increasing infiltration, restoring riparian wetlands, and reducing connected impervious surface to mitigate riverine and stormwater floods for exposed urban populations. Cities were then categorized based on relative opportunity potential to reduce identified risks through watershed conservation activities. We find high opportunities for watershed activities to mitigate at least one of the risks in 42 cities, potentially benefiting 96 million people or around 60% of the urbanites living in the 70 largest cities in Latin America. We estimate water quality could be improved for 72 million people in 27 cities, riverine flood risk mitigated for 5 million people in 13 cities, and stormwater flooding mitigated for 44 million people in 14 cities. We identified five cities with the potential to simultaneously enhance water quality and mitigate flood risks, and in contrast, six cities where conservation efforts are unlikely to meaningfully mitigate either risk. Institutions investing in natural infrastructure to improve water security in Latin America can maximize their impact by focusing on specific watershed conservation activities either for cleaner drinking water or flood mitigation in cities identified in our analysis where these interventions are most likely to reduce risk.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1029/2022GL099872", "year": 2022, "title": "Evaluation of extreme soil moisture conditions during the 2020 sahel floods and implications for disease outbreaks", "abstract": "The June-October 2020 growing season was characterized by sustained and extreme flooding across the African Sahel. One consequence of flooding events such as this is outbreaks of vector borne diseases (VBDs) which are often associated with climate anomalies. In this study, data from the soil moisture active passive (SMAP) mission is used with other soil moisture and precipitation data to show that the 2020 Sahelian growing season was the most extreme over the past four decades, ranking first in seasonally accumulated precipitation, which on average exceeded the climatology by around 300 mm. VBD outbreaks of Rift Valley fever and Chikungunya followed in Mauritania/Senegal and Chad, respectively. In some cases, soil moisture is a better indicator of VBD outbreak risk than precipitation, which has so far been more commonly used in studies of VBD outbreaks. It is expected that this finding will inform future monitoring and prediction efforts for VBD risk.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41598-020-67736-6", "year": 2020, "title": "Projections of global-scale extreme sea levels and resulting episodic coastal flooding over the 21st Century", "abstract": "Global models of tide, storm surge, and wave setup are used to obtain projections of episodic coastal flooding over the coming century. The models are extensively validated against tide gauge data and the impact of uncertainties and assumptions on projections estimated in detail. Global hotspots where there is projected to be a significant change in episodic flooding by the end of the century are identified and found to be mostly concentrated in north western Europe and Asia. Results show that for the case of, no coastal protection or adaptation, and a mean RCP8.5 scenario, there will be an increase of 48% of the worlds land area, 52% of the global population and 46% of global assets at risk of flooding by 2100. A total of 68% of the global coastal area flooded will be caused by tide and storm events with 32% due to projected regional sea level rise.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.3390/RS12040643", "year": 2020, "title": "Automatic flood duration estimation based on multi-sensor satellite data", "abstract": "Flood duration is a crucial parameter for disaster impact assessment as it can directly influence the degree of economic losses and damage to structures. It also provides an indication of the spatio-temporal persistence and the evolution of inundation events. Thus, it helps gain a better understanding of hydrological conditions and surface water availability and provides valuable insights for land-use planning. The objective of this work is to develop an automatic procedure to estimate flood duration and the uncertainty associated with the use of multi-temporal flood extent masks upon which the procedure is based. To ensure sufficiently high observation frequencies, data from multiple satellites, namely Sentinel-1, Sentinel-2, Landsat-8 and TerraSAR-X, are analyzed. Satellite image processing and analysis is carried out in near real-time with an integrated system of dedicated processing chains for the delineation of flood extents from the range of aforementioned sensors. The skill of the proposed method to support satellite-based emergency mapping activities is demonstrated on two cases, namely the 2019 flood in Sofala, Mozambique and the 2017 flood in Bihar, India.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.25394/PGS.14204309.V1", "year": 2021, "title": "Quantifying the impacts of inundated land area on streamflow and crop development", "abstract": "The presented work quantifies the impacts of inundated land area (ILA) on streamflow and crop development in the Upper Midwest, which is experiencing a changing climate with observed increases in temperature and precipitation. Quantitative information is needed to understand how upland and downstream stakeholders are impacted by ILA; yet the temporal and spatial extent of ILA and the impact of water storage on flood propagation is poorly understood. Excess water in low gradient agricultural landscapes resulting in ILA can have opposing impacts. The ILA can negatively impact crop development causing financial loss from a reduction or total loss in yield while conversely, ILA can also benefit downstream stakeholders by preventing flood damage from the temporary surface storage that slows water movement into channels. This research evaluates the effects of ILA on streamflow and crop development by leveraging the utility of remotely sensed observations and models. The influence of ILA on streamflow is investigated in the Red River basin, a predominantly agricultural basin with a history of damaging flood events. An inundation depth-area (IDA) parameterization was developed to parameterize the ILA in a hydrologic model, the Variable Infiltration Capacity (VIC) model, using remotely sensed observations from the MODIS Near Real-Time Global Flood Mapping product and discharge data. The IDA parameterization was developed in a subcatchment of the Red River basin and compared with simulation scenarios that did and did not represent ILA. The model performance of simulated discharge and ILA were evaluated, where the IDA parameterization outperformed the control scenarios. In addition, the simulation results using the IDA parameterization were able to explain the dominant runoff generation mechanism during the winter-spring and summer-fall seasons. The IDA parameterization was extended to the Red River basin to analyze the effects of ILA on the timing and magnitude of peak flow events where observed discharge revealed an increasing trend and magnitude of summer peak flow events. The results also showed that the occurrence of peak flow events is shifting from unimodal to bimodal structure, where peak flow events are dominant in the spring and summer seasons. By simulating ILA in the VIC model, the shift in occurrence of peak flow events and magnitude are better represented compared to simulations not representing ILA. The impacts of ILA on crop development are investigated on soybean fields in west-central Indiana using proximal remote sensing from unmanned aerial systems (UASs). Models sensitive to ILA were developed from the in-situ and UAS data at the plot scale to estimate biomass and percent of expected yield between the R4-R6 stages at the field scale. Low estimates of biomass and percent of expected yield were associated with mapped observations of ILA. The estimated biomass and percent of expected yield were useful early indicators to identify soybean impacted by excess water at the field scale. The models were applied to satellite imagery to quantify the impacts of ILA on soybean development over larger areas and multiple years. The estimated biomass and percent of expected yield correlated well with the observed data, where low model estimates were also associated with mapped observations of ILA and periods of excessive rainfall. The results of the work link the impacts of ILA on streamflow and crop development, and why it is important to quantify both in a changing climate. By representing ILA in hydrologic models, we can improve simulated streamflow and ILA and represent dominant physical process that influence hydrologic responses and represent shift and seasonal occurrence of peak flow events. In the summer season, where there is an increased occurrence of peak flow events, it is important to understand the impacts of ILA on crop development. By quantifying the impacts of ILA on soybean development we can analyze the spatiotemporal impacts of excess water on soybean development and provide stakeholders with early assessments of expected yield which can help improvement management decisions.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1088/1748-9326/AC9197", "year": 2022, "title": "Urbanizing the floodplain: global changes of imperviousness in", "abstract": "Abstract\r\n Cities have historically developed close to rivers and coasts, increasing human exposure to flooding. That exposure is exacerbated by changes in climate and population, and by urban encroachment on floodplains. Although the mechanisms of how urbanization affects flooding are relatively well understood, there have been limited efforts to assess the magnitude of floodplain encroachment globally and how it has changed in both space and time. Highly resolved global datasets of both flood hazard and changes in urban area from 1985 to 2015 are now available, enabling the reconstruction of the history of floodplain encroachment at high spatial resolutions. Here we show that the urbanized area in floodplains that have an average probability of flooding of 1/100 years, has almost doubled since 1985. Further, the rate of urban expansion into these floodplains increased by a factor of 1.5 after the year 2000. We also find that urbanization rates were highest in the most hazardous areas of floodplains, with population growth in these urban floodplains suggesting an accompanying increase in population density. These results reveal the scope, trajectory and extent of global floodplain encroachment. With tangible implications for flood risk management, these data could be directly used with integrated models to assess adaptation pathways for urban flooding.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/B978-0-12-812782-7.00016-3", "year": 2019, "title": "Annual Flood Monitoring Using Synchronized Floodwater Index in 2010 Indus River Flood", "abstract": "Flood detection algorithms are able to generate near real-time flood proxy maps on regional and global scales on a daily basis through the use of multiple spaceborne sensors. In this chapter, we introduce a new algorithm for detecting annual floodwater changes using a hybrid conditional process that is incorporated into the Synchronized Multiple-Floodwater Index (SfWI2), a threshold-based statistical flood detection approach, coupled with in situ hydrological data. SfWI2 was applied to the 2010 Indus flood event, a recent extreme flood case, in order to achieve more accurate flood detection at a transboundary river-basin level and an effective emergency response in the early stage of a flood disaster. The resultant flood map shows good agreement between the MODIS-derived flood proxy map and high-resolution satellite images at the representative barrage stations.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/HESS-23-3933-2019", "year": 2019, "title": "Global-scale human pressure evolution imprints on sustainability of river systems", "abstract": "Abstract. Human pressures on river systems pose a major threat to the sustainable development of human societies in the twenty-first century. Previous studies showed that a large part of global river systems was already exposed to relevant anthropogenic pressures at the beginning of this century. A relevant question that has never been explained in the literature so far is whether these pressures are increasing in time, therefore representing a potential future challenge to the sustainability of river systems. This paper proposes an index we call Differential Human Pressure on Rivers (DHPR) to quantify the annual evolution of human pressure on river systems. DHPR identifies a per-year percentage increment (or decrement) of normalized human pressures on river systems (i.e., ratio of annual values to long-term average). This index, based on annual nightlights and stationary discharge data, is estimated for 2195 major river basins over a period of 22 years, from 1992 to 2013. The results show that normalized annual human pressure on river systems increased globally, as indicated by an average DHPR value of 1.9 % per year, whereby the greatest increase occurred in the northern tropical and equatorial areas. The evaluation of DHPR over this 22-year period allows the identification of hot-spot areas, therefore offering guidance on where the development and implementation of mitigation strategies and plans are most needed (i.e., where human pressure is strongly increasing).", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/EN13143685", "year": 2020, "title": "Metamodeling for uncertainty quantification of a flood wave model for concrete dam breaks", "abstract": "Uncertainties in instantaneous dam-break floods are difficult to assess with standard methods (e.g., Monte Carlo simulation) because of the lack of historical observations and high computational costs of the numerical models. In this study, polynomial chaos expansion (PCE) was applied to a dam-break flood model reflecting the population of large concrete dams in Switzerland. The flood model was approximated with a metamodel and uncertainty in the inputs was propagated to the flow quantities downstream of the dam. The study demonstrates that the application of metamodeling for uncertainty quantification in dam-break studies allows for reduced computational costs compared to standard methods. Finally, Sobol sensitivity indices indicate that reservoir volume, length of the valley, and surface roughness contributed most to the variability of the outputs. The proposed methodology, when applied to similar studies in flood risk assessment, allows for more generalized risk quantification than conventional approaches.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2017WR021987", "year": 2018, "title": "Sensitivity of Probable Maximum Flood in a Changing Environment", "abstract": "With likely increases in probable maximum precipitation (PMP) in a changing environment, critical infrastructures such as major reservoirs and nuclear power plants are subject to elevated risk. To understand how factors such as PMP variability, climate change, land use land cover (LULC) change, antecedent soil moisture conditions, and reservoir storage may individually or jointly affect the magnitude of probable maximum flood (PMF), we conducted integrated hydrometeorological simulations involving both the Weather Research Forecasting model and the distributed hydrologic model (DHSVM) over the Alabama-Coosa-Tallapoosa (ACT) River Basin in the southeastern United States. A total of 120 relative humidity-maximized PMP storms under historic and projected future climate conditions were used to drive DHSVM in current and projected future LULC conditions. Overall, PMP and PMF are projected to increase significantly over the ACT River Basin. Sources of meteorological forcing data sets and climate change were found to be the most sensitive factors affecting PMF, followed by antecedent soil moisture, reservoir storage, and then LULC change. The ensemble of PMP and PMF simulations, along with their sensitivity, allows us to better quantify the potential risks associated with hydroclimatic extreme events to critical infrastructures for energy-water security.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.5194/NHESS-21-1071-2021", "year": 2021, "title": "The uncertainty of flood frequency analyses in hydrodynamic model simulations", "abstract": "Abstract. Assessing the risk of a historical-level flood is essential for regional flood protection and resilience establishment. However, due to the limited spatiotemporal coverage of observations, the impact assessment relies on model simulations and is thus subject to uncertainties from cascade physical processes. This study assesses the flood hazard map with uncertainties subject to different combinations of runoff inputs, variables for flood frequency analysis and fitting distributions based on estimations by the CaMa-Flood global hydrodynamic model. Our results show that deviation in the runoff inputs is the most influential source of uncertainties in the estimated flooded water depth and inundation area, contributing more than 80 % of the total uncertainties investigated in this study. Global and regional inundation maps for floods with 1-in-100 year return periods show large uncertainty values but small uncertainty ratios for river channels and lakes, while the opposite results are found for dry zones and mountainous regions. This uncertainty is a result of increasing variation at tails among various fitting distributions. In addition, the uncertainty between selected variables is limited but increases from the regular period to the rarer floods, both for the water depth at points and for inundation area over regions. The uncertainties in inundation area also lead to uncertainties in estimating the population and economy exposure to the floods. In total, inundation accounts for 9.1 % [8.1 %10.3 %] of the land area for a 1-in-100 year flood, leading to 13.4 % [12.1 %15 %] of population exposure and 13.1 % [11.8 %14.7 %] of economic exposure for the globe. The flood exposure and uncertainties vary by continent and the results in Africa have the largest uncertainty, probably due to the limited observations to constrain runoff simulations, indicating a necessity to improve the performance of different hydrological models especially for data-limited regions.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/S10584-021-03130-Z", "year": 2021, "title": "Global costs of protecting against sea-level rise at 1.5 to 4.0\u00b0 C", "abstract": "Sea levels will rise, even with stringent climate change mitigation. Mitigation will slow the rate of rise. There is limited knowledge on how the costs of coastal protection vary with alternative global warming levels of 1.5 to 4.0 C. Analysing six sea-level rise scenarios (0.74 to 1.09 m, 50th percentile) across these warming levels, and five Shared Socioeconomic Pathways, this paper quantifies the economic costs of flooding and protection due to sea-level rise using the Dynamic Interactive Vulnerability Assessment (DIVA) modelling framework. Results are presented for World Bank income groups and five selected countries from the present to 2100. Annual sea flood damage costs without additional adaptation are more influenced by socio-economic development than sea-level rise, indicating that there are opportunities to control risk with development choices. In contrast, annual sea dike investment costs are more dependent on the magnitude of sea-level rise. In terms of total costs with adaptation, upper middle, low middle and low income groups are projected to have higher relative costs as a proportion of GDP compared with high income groups. If low income countries protected now, flood costs could be reduced after 2050 and beyond. However, without further adaptation, their coasts will experience growing risks and costs leaving them increasingly reliant on emergency response measures. Without mitigation or adaptation, greater inequalities in damage costs between income groups could result. At country level, annual sea flood damage costs without additional adaptation are projected to rapidly increase with approximately 0.2 m of sea-level rise, leaving limited time to plan and adapt.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.WACE.2022.100495", "year": 2022, "title": "The tale of three floods: From extreme events and cascades of highs to", "abstract": "Right after a devastating multi-year drought, a number of flood events with unprecedented spatial extent hit different parts of Iran over the 2-week period of March 17th to April 1st, 2019, causing a human disaster and substantial loss of assets and infrastructure across urban and rural areas. Here, we investigate natural (e.g., rainfall, snow accumulation/melt, soil moisture) and anthropogenic drivers (e.g., deforestation, urbanization, and management practices) of these events using a range of ground-based data and satellite observations. These drivers can range from exceptionally extreme rainfall intensities, to cascades of several extreme and moderate events, and various anthropogenic interventions that exacerbated flooding. Our results reveal strong compounding impacts of natural drivers and anthropogenic triggers in escalating flood risks to unprecedented levels. We argue that a new form of floods, i.e. anthropogenic floods, is becoming more common and should be recognized during the \"Anthropocene\". This specific form of floods refers to high to extreme streamflow/runoff events that are primarily caused, or largely exacerbated, by anthropogenic drivers. We demonstrate how the growing risk of anthropogenic floods can be assessed using a wide range of climatic and non-climatic satellite and in-situ data.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.EARSCIREV.2019.102995", "year": 2020, "title": "Altai megafloods\u2014The temporal context", "abstract": "Pleistocene floods, from ice-dammed lakes in the Russian Altai Mountains, are among the largest freshwater megafloods in Earth history. Improved dating techniques have led to new dates constraining the timing of flood erosional and depositional events. In addition to a variety of interpretations and explanations of event histories, a proliferation of dates may increase confusion with respect to the characteristics and chronology of the flood events. In a succinct review, the main ice-dammed lakes features, the outburst floods and their repeated formation are presented. Among other indicators, interbedded units of lacustrine deposits and outburst flood sediments in Inya River valley demonstrate conclusively that there was a series of outburst floods with significant evidence for at least three high magnitude flood events. Prior study focussed on the interpretation of: lake sediments, shorelines, giant bars, gravel dunes; dated by radiocarbon, luminescence and cosmogenic nuclide assay. The literature presents sometimes contradictory findings with respect to flood chronology. These different interpretations, evidence and arguments, are reviewed for plausibility and consistency. This consideration includes methodical and technical dating problems: limited bleaching for luminescence techniques; low purity for cosmogenic nuclide dating; contamination of samples dated by radiocarbon assay. At the current stage of knowledge, the main period of repeated high magnitude outburst floods occurred between 28 ka and 15 ka BP. Indicators of earlier events are less distinct. Possible younger smaller floods can be identified after 15 ka BP, but it is difficult to relate these to catastrophic lake-draining. Rather, they may relate to non-catastrophic draining of residual small lakes within the larger basins. The termination of the lake period took place before 9.90.3 ka cal BP in the Kuray Basin, and in the Chuya Basin before 8.20.2 ka cal BP. Indicators are lacking for any drainage events after 7.70.6 ka as indicated by OSL ages of aeolian deposits at low elevations in the Katun valley. Relating the outburst floods to the temporal and spatial dynamics of the impounding glacier is challenging as, with regard to Pleistocene glaciation, several conceptual models have been established supported by field evidence that, in part, can be contradictory. During the period of the high magnitude outburst floods the extension/thickness of the impounding valley glaciers were sufficient to form deep glacial lakes around the time of the last glacial maximum (LGM); yet the timing of the LGM remains controversial. Transferring glacial chronologies from mountain areas adjacent to the Russian Altai Mountains to the environment of the megafloods does not provide a clearer picture as there is evidence for maximum stages at MIS 4 and MIS 3 - in addition to recent postulations of a LGM in MIS 2 for the Russian Altai Mountains. The Russian Altai Mountains are located in a climatic transitional zone across which different LGM stages could be developed due to different moisture availability and temperature chronologies. The effects of spatially-variable rain-shadows influencing the supply of moisture from the regional prevailing winds and local moisture sources from expanded ice-dammed lakes complicates the picture and require further investigations.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1038/S41598-021-83279-W", "year": 2021, "title": "Global exposure to flooding from the new CMIP6 climate model projections", "abstract": "Estimates of future flood risk rely on projections from climate models. The relatively few climate models used to analyze future flood risk cannot easily quantify of their associated uncertainties. In this study, we demonstrated that the projected fluvial flood changes estimated by a new generation of climate models, the collectively known as Coupled Model Intercomparison Project Phase 6 (CMIP6), are similar to those estimated by CMIP5. The spatial patterns of the multi-model median signs of change (+ or ) were also very consistent, implying greater confidence in the projections. The model spread changed little over the course of model development, suggesting irreducibility of the model spread due to internal climate variability, and the consistent projections of models from the same institute suggest the potential to reduce uncertainties caused by model differences. Potential global exposure to flooding is projected to be proportional to the degree of warming, and a greater threat is anticipated as populations increase, demonstrating the need for immediate decisions.", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1007/978-981-16-8225-4_6", "year": 2022, "title": "Spatial Analyses of Cyclone Amphan Induced Flood Inundation Mapping Using Sentinel-1A SAR Images Through GEE Cloud", "abstract": "The study focused on mapping flood inundation in the lower Indo-Gangetic plains in Purba Medinipur district, West Bengal, India, using synchronized C-band Sentinel-1A synthetic aperture radar satellite images with a cloud computing API on the GEE. The study showed that a considerable proportion of the district 3978.93 km2 was flood inundated during May 2020 due to heavy rainfall and severe cyclone Amphan. Impact of flood inundation was found in agricultural areas (35.93% of the total agricultural land), followed by built-up area (5.03% of the built-up area) that affected a large population (30.85% of the total population), in the study area. Validation assessment is carried out for final flood layer mapping with seven flood status parameters such as VV, VH backscatter of Sentinel-1A, precipitation, NDVI, NDWI, soil moisture, and elevation data acquired in the month of May 2020. The validation accuracy estimation of the flood inundation map through the AUROC method along with the four machine learning models showed that the Naive Bayes (AUROC = 92.6%) outperformed the SVM (AUROC = 89.9%), RF (AUROC = 89.4%), and logistic regression (AUROC = 88.5%) models. Cloud-based GEE services provide quick flood inundation mapping with associated damage information that can be beneficial for disaster management and emergency response. This will support crucial policy makers and stakeholders in creating urgent decisions for flood investigation for sustainable environment disaster risk mitigation management. The study requires implementing a cohesive, multi-decision-making approach with importance on self-reliance of the community for nourishment with local practices and resources.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1080/10106049.2022.2076919", "year": 2022, "title": "Assessing the risk posed by flash floods to the transportation network", "abstract": "", "labels": [ { "id": 9, "name": "Floods" } ] }, { "doi": "10.1175/JHM-D-20-0250.1", "year": 2021, "title": "Key factors influencing the severity of fluvial flood hazard from tropical cyclones", "abstract": "Abstract Knowledge of the key drivers of the severity of river flooding from tropical cyclones (TCs) is vital for emergency preparedness and disaster risk reduction activities. This global study examines landfalling TCs in the decade from 2010 to 2019 to identify those characteristics that influence whether a storm has an increased flood hazard. The highest positive correlations are found between flood severity and the total precipitation associated with the TC. Significant negative correlations are found between flood severity and the translation speed of the TC, indicating that slower-moving storms that rain over an area for longer tend to have higher flood severity. Larger and more intense TCs increase the likelihood of having a larger area affected by severe flooding but not its duration or magnitude, and it is found that the fluvial flood hazard can be severe in all intensity categories of TC, including those of tropical storm strength. Catchment characteristics such as antecedent soil moisture and slope also play a role in modulating flood severity, and severe flooding is more likely in cases in which multiple drivers are present. The improved knowledge of the key drivers of fluvial flooding in TCs can help to inform research priorities to help with flood early warning, such as increasing the focus on translation speed in model evaluation and impact-based forecasting.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1021/ACS.EST.1C05955", "year": 2021, "title": "Surface Flooding as a Key Driver of Groundwater Arsenic Contamination in Southeast Asia", "abstract": "", "labels": [ { "id": 9, "name": "Floods" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1080/22797254.2021.1983471", "year": 2021, "title": "Rapid monitoring of cyclone induced flood through an automated approach using multi\u2013temporal Earth Observation (EO) images in RSS CloudToolbox platform", "abstract": "The new era of cloud platform technologies opens up many opportunities for near real-time dissemination of disaster information to the end-users. The present study utilizes the European Space Agency (ESA) Research and Service Support (RSS) CloudToolbox platform to monitor the spatio-temporal dynamics of a flood event. A collective flood monitoring framework is formulated to rapidly assess cyclone-induced flood in the CloudToolbox platform. The outputs of the framework are spatio-temporal maps of flood extent, depth, and hot spot zones. The framework utilizes Earth Observation (EO) images such as optical and C-band Synthetic Aperture Radar (SAR) images and an automatic Kittler and Illingworth thresholding algorithm for rapid flood mapping. The temporal flood depth maps are created with the Floodwater Depth Estimation Tool (FwDET) which requires only two input parameters, viz. flood extent, and Digital Elevation Model (DEM). Subsequently, flood hotspot zones are also identified. We tested the flood monitoring framework on Amphan cyclone-induced flood event at both regional and local levels. The spatio-temporal flood extent, depth, and hot spot maps are generated for the Amphan cyclone event and a 97% overall accuracy is achieved at the local level. The entire process took less than one hour for regional and local level analysis.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.JCLEPRO.2022.131498", "year": 2022, "title": "Urban heat island and thermal comfort of Esfahan City (Iran) during COVID-19 lockdown", "abstract": "The Urban Heat Island (UHI), driven in part by urban green space transformation, and resulting in bioclimatic stress, is one of the major environmental problems facing cities today. A brief reprise in UHI severity is hypothesised to have occurred for many cities during COVID-19 lockdown, as a result of the marked reduction in individual and industrial activities. This study explores the UHI the city of Esfahan, one of the major metropolises of Iran, comparing the urban temperature for the period 20 March to 20 April 2020, the first lockdown period in Iran, with a long term mean for this month calculated from 2000 to 2019. During the lockdown period, the UHI effect covered a much smaller land area than in all prior years investigated. The land surface area which experienced heat stress reduced significantly during the lockdown period, and the total energy heating requirement (heat degree days) increased by 23,945.2 day calories compared to the long term average. These results demonstrate the significant changes in UHI and related variables during lockdown. While lockdown regulations are not sustainable in the long run, the improvements recorded demonstrate the potential to mitigate anthropogenic heating.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.SCITOTENV.2020.142334", "year": 2021, "title": "Surface urban heat islands in Italian metropolitan cities: Tree cover and impervious surface influences", "abstract": "Land surface temperature (LST) predictors, such as impervious and vegetated surfaces, strongly influence the urban landscape mosaic, also changing microclimate conditions and exacerbating the surface urban heat island (SUHI) phenomenon. The aim of this study was to investigate the summer daytime SUHI phenomenon and the role played by impervious and tree cover surfaces in the 10 Italian peninsular metropolitan cities. Summer daytime LST values were assessed by using MODIS data referred to the months of June, July and August from 2016 to 2018. High spatial resolution (10 m) of impervious surface and tree cover layers was calculated based on open-data developed by the Italian National Institute for Environmental Protection and Research. A novel informative urban surface landscape layer was developed combining impervious surfaces and tree cover densities and its mapping for metropolitan cities was performed. Summer daytime SUHI rose significantly, increased especially in inland cities, by increasing the size of areas with low tree cover densities in the metropolitan core (or decreasing areas with low tree cover densities outside the metropolitan core), further increasing its intensity when the impervious density grew. A mitigating effect of the sea on daytime LST and SUHI was observed on coastal cities. The most intense SUHI phenomenon was observed in Turin (the largest Italian metropolitan city): for every 10% increase in areas with highly impervious surfaces and low tree cover densities in the metropolitan core, the SUHI significantly (p ", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.APGEOG.2015.07.006", "year": 2015, "title": "Policy-relevant indicators for mapping the vulnerability of urban populations to extreme heat events: A case study of Philadelphia", "abstract": "The recent global increase in extreme heat events linked to climate change is projected to continue. The additive effect of urban heat islands from impervious surfaces and urban heat emissions (e.g., from transportation and building cooling) exacerbates extreme heat events in urban areas, exposing dense populations to extreme heat with implications for human health. Ground- and satellite-based data on urban and suburban temperatures and vegetation over a historical period can help identify temporal and geospatial trends in heat exposure. A set of indicators has been developed to map the exposure, social sensitivity, and vulnerability of urban populations to heat wave health impacts. Guided by an Advisory Group of local planners in the pilot city of Philadelphia, localized trends of increasing urban extreme heat events using MODIS Land Surface Temperature (LST) data, confirmed with urban and non-urban temperature monitor data were identified. For the Philadelphia study area, the number of heat-event days in the urban setting has increased from approximately 4 days in 1980 to almost 12 days in 2013, while the non-urban setting has consistently experienced 5 days of heat events per year across the time period. Warmer micro-climates with limited vegetative cooling and elevated LSTs were also identified. The exposure indicator was combined with areas of high social sensitivity (e.g., low-income and elderly) to create a vulnerability indicator, showing significant overlap between highly exposed and highly sensitive populations. As a measure of the adaptive capacity of local governments to reduce the urban heat island, evidence of targeted vegetation increases or reduced localized temperatures linked to urban greening and cooling programs were sought, though none were of a scale to be identified by the 1 km satellite data utilized. The indicators have helped local decision makers to understand patterns of vulnerability, and may be used in the future to target adaptation actions and measure results (LST reduction or vegetation increase) from existing adaptation actions.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1002/2016JD026074", "year": 2017, "title": "Urban emissions of water vapor in winter", "abstract": "Elevated water vapor (H2Ov) mole fractions were occasionally observed downwind of Indianapolis, IN, and the Washington, D.C.-Baltimore, MD, area during airborne mass balance experiments conducted during winter months between 2012 and 2015. On days when an urban H2Ov excess signal was observed, H2Ov emission estimates range between 1.6 \u00d7 104 and 1.7 \u00d7 105 kg s-1 and account for up to 8.4% of the total (background + urban excess) advected flow of atmospheric boundary layer H2Ov from the urban study sites. Estimates of H2Ov emissions from combustion sources and electricity generation facility cooling towers are 1-2 orders of magnitude smaller than the urban H2Ov emission rates estimated from observations. Instances of urban H2Ov enhancement could be a result of differences in snowmelt and evaporation rates within the urban area, due in part to larger wintertime anthropogenic heat flux and land cover differences, relative to surrounding rural areas. More study is needed to understand why the urban H2Ov excess signal is observed on some days, and not others. Radiative transfer modeling indicates that the observed urban enhancements in H2Ov and other greenhouse gas mole fractions contribute only 0.1\u00b0C d-1 to the urban heat island at the surface. This integrated warming through the boundary layer is offset by longwave cooling by H2Ov at the top of the boundary layer. While the radiative impacts of urban H2Ov emissions do not meaningfully influence urban heat island intensity, urban H2Ov emissions may have the potential to alter downwind aerosol and cloud properties.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS13193797", "year": 2021, "title": "Fine-Scale Urban Heat Patterns in New York City Measured by ASTER", "abstract": "Urban areas have very complex spatial structures. These spatial structures are primarily composed of a complex network of built environments, which evolve rapidly as the cities expand to meet the growing populations demand and economic development. Therefore, studying the impact of spatial structures on urban heat patterns is extremely important for sustainable urban planning and growth. We investigated the relationship between surface temperature obtained by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER, at 90 m spatial resolution) and different urban components based on high-resolution QuickBird satellite imagery classification. We further investigated the relationships between ASTER-derived surface temperature and building footprint and land use information acquired by the New York City (NYC) Department of City Planning. The ASTER image reveals fine-scale urban heat patterns in the NYC metropolitan region. The impervious-medium and dark surfaces, along with bright covers, generate higher surface temperatures. Even with highly reflective urban surfaces, the presence of impervious materials leads to an increased surface temperature. At the same time, trees and shadows cast by buildings effectively reduce urban heat; on the contrary, grassland does not reduce or amplify urban heat. The data aggregated to the census tract reveals high-temperature hotspots in Queens, Brooklyn, and the Bronx region of NYC. These clusters are associated with industrial and manufacturing areas and multi-family walk-up buildings as dominant land use. The census tracts with more trees and higher building height variability showed cooling effects, consistent with shadows cast by high-rise buildings and trees. The results of this study can be valuable for urban heat island modeling on the impact of shadow generated by building heights variability and trees on small-scale surface temperature patterns since recent image reveals similar hotspot locations. This study further helps identify the risk areas to protect public health.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/S22082894", "year": 2022, "title": "Urban Warming of the Two Most Populated Cities in the Canadian Province", "abstract": "Continuous urban expansion transforms the natural land cover into impervious surfaces across the world. It increases the citys thermal intensity that impacts the local climate, thus, warming the urban environment. Surface urban heat island (SUHI) is an indicator of quantifying such local urban warming. In this study, we quantified SUHI for the two most populated cities in Alberta, Canada, i.e., the city of Calgary and the city of Edmonton. We used the moderate resolution imaging spectroradiometer (MODIS) acquired land surface temperature (LST) to estimate the day and nighttime SUHI and its trends during 20012020. We also performed a correlation analysis between SUHI and selected seven influencing factors, such as urban expansion, population, precipitation, and four large-scale atmospheric oscillations, i.e., Sea Surface Temperature (SST), Pacific North America (PNA), Pacific Decadal Oscillation (PDO), and Arctic Oscillation (AO). Our results indicated a continuous increase in the annual day and nighttime SUHI values from 2001 to 2020 in both cities, with a higher magnitude found for Calgary. Moreover, the highest value of daytime SUHI was observed in July for both cities. While significant warming trends of SUHI were noticed in the annual daytime for the cities, only Calgary showed it in the annual nighttime. The monthly significant warming trends of SUHI showed an increasing pattern during daytime in June, July, August, and September in Calgary, and March and September in Edmonton. Here, only Calgary showed the nighttime significant warming trends in March, May, and August. Further, our correlation analysis indicated that population and built-up expansion were the main factors that influenced the SUHI in the cities during the study period. Moreover, SST indicated an acceptable relationship with SUHI in Edmonton only, while PDO, PNA, and AO did not show any relation in either of the two cities. We conclude that population, built-up size, and landscape pattern could better explain the variations of the SUHI intensity and trends. These findings may help to develop the adaptation and mitigating strategies in fighting the impact of SUHI and ensure a sustainable city environment.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.BUILDENV.2021.108677", "year": 2022, "title": "Effects of heat waves on urban warming across different urban morphologies and climate zones", "abstract": "Heat wave (HW) periods, which are characterized by unusual high temperatures and heat stress, are known as one of the global issues that negatively affect the land and atmosphere, especially in urban areas. Higher urbanization rates in cities may result in high temperature warming, which is known as the Urban Heat Island (UHI). Recently, researchers have revealed pronounced effects based on HW and UHI interactions; however, studies that linked their effects with surface energy fluxes in different urban landscape and climate are still inadequate. This study utilized the Community Land Model (CLM) to assess the effect of HW towards UHI, while considering energy fluxes variations in Seoul, Tokyo, Kuala Lumpur, and Melbourne, with different climate influences and urban morphologies. Generally, Seoul and Tokyo showed intense HW magnitude from 2000 to 2018 based on the HW indices. The surface energy flux components demonstrated a distinct pattern especially from 11:00 to 17:00, with the exception of sensible heat in Melbourne. Further energy-flux partitioning revealed that changes in the heat storage ratio were most significant in Seoul, with 1.39 partitioning due to its larger impervious area. A smaller height-to-width (H/W) canyon ratio of open mid-rise building has enhanced urban warming in Melbourne, whereas smaller impervious and larger pervious road fraction could mitigate urban warming effects in Kuala Lumpur. Seoul showed the highest changes in daytime UHI under HW at 2.01 C, due to the low convection efficiency in compact high-rise building, while nighttime UHI was highly influenced by heat storage and anthropogenic heat release.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.UCLIM.2021.101074", "year": 2021, "title": "Reexamining the relationship between surface urban heat island intensity and annual precipitation: Effects of reference rural land cover", "abstract": "Previous studies have shown that surface urban heat island intensity (SUHII) across cities is significantly positively correlated with mean annual precipitation (MAP), including linear and nonlinear correlations. Different explanations for these SUHIIMAP relations have been suggested, yet a systematic examination of the impact of variability in reference rural land cover on geographic variations of daytime SUHII and the relation with MAP is still lacking. In this study, the previously proposed SUHIIMAP relations are reexamined by investigating 60 cities across North America and 346 cities across the globe, respectively. The focus of the study is on the role of variability of reference land cover types in the SUHIIMAP relations. The 10-yr time series of satellite-observed land surface temperature, precipitation and solar radiation data, in conjunction with global land cover data, are used for analysis. Our results confirm the reproducibility of both the linear and nonlinear SUHIIMAP relations; nevertheless, the significant positive correlations between the daytime SUHII and the MAP are found to be dependent mainly on the variability of the reference land cover types associated with MAP levels (i.e., varying from desert to tree cover). In contrast, when a constant land cover type is taken as the reference, no significant correlations between the daytime SUHII and the MAP are observed. The finding highlights that respecting SUHI intensity as a relative measure and accounting for variability of reference land cover is of crucial importance for proper interpretation and understanding of SUHI.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.JAG.2020.102066", "year": 2020, "title": "Estimating spatio-temporal air temperature in London (UK) using machine learning and earth observation satellite data", "abstract": "Urbanisation generates greater population densities and an increase in anthropogenic heat generation. These factors elevate the urbanrural air temperature (Ta) difference, thus generating the Urban Heat Island (UHI) phenomenon. Ta is used in the fields of public health and epidemiology to quantify deaths attributable to heat in cities around the world: the presence of UHI can exacerbate exposure to high temperatures during summer periods, thereby increasing the risk of heat-related mortality. Measuring and monitoring the spatial patterns of Ta in urban contexts is challenging due to the lack of a good network of weather stations. This study aims to produce a parsimonious model to retrieve maximum Ta (Tmax) at high spatio-temporal resolution using Earth Observation (EO) satellite data. The novelty of this work is twofold: (i) it will produce daily estimations of Tmax for London at 1 km2 during the summertime between 2006 and 2017 using advanced statistical techniques and satellite-derived predictors, and (ii) it will investigate for the first time the predictive power of the gradient boosting algorithm to estimate Tmax for an urban area. In this work, 6 regression models were calibrated with 6 satellite products, 3 geospatial features, and 29 meteorological stations. Stepwise linear regression was applied to create 9 groups of predictors, which were trained and tested on each regression method. This study demonstrates the potential of machine learning algorithms to predict Tmax: the gradient boosting model with a group of five predictors (land surface temperature, Julian day, normalised difference vegetation index, digital elevation model, solar zenith angle) was the regression model with the best performance (R2 = 0.68, MAE = 1.60 C, and RMSE = 2.03 C). This methodological approach is capable of being replicated in other UK cities, benefiting national heat-related mortality assessments since the data (provided by NASA and the UK Met Office) and programming languages (Python) sources are free and open. This study provides a framework to produce a high spatio-temporal resolution of Tmax, assisting public health researchers to improve the estimation of mortality attributable to high temperatures. In addition, the research contributes to practice and policy-making by enhancing the understanding of the locations where mortality rates may increase due to heat. Therefore, it enables a more informed decision-making process towards the prioritisation of actions to mitigate heat-related mortality amongst the vulnerable population.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.JENVMAN.2019.110006", "year": 2020, "title": "Anthropogenic forcing exacerbating the urban heat islands in India", "abstract": "Urban heat island (UHI) phenomena is among the major consequences of the alteration of earth's surface due to human activities. The relatively warmer temperatures in urban areas compared to suburban areas (i.e. UHI) has potential health hazards, such as mortality due to high temperatures and heat waves. In addition, UHI situation demands more energy (e.g. fans and air-conditioners) that would trigger greenhouse gas emissions. Studies on UHI intensity help to assess its impact on urban population, city planning, and urban health planning. This is particularly important for a country like India, where 32% people (~7% of total world population), live in urban areas. We conducted a detailed study on surface UHI intensity (SUHII), which is the difference between urban and surrounding rural land surface temperatures, across all seasons in 44 major cities of India, which shows that mean daytime SUHII is positive (up to 2 C) for most cities, as analysed from satellite temperature measurements for the period 20002017, in contrast to previous studies. However, although statistically insignificant, most cities show a positive trend in SUHII for monsoon and post-monsoon periods, but negative for winter and summer seasons. The increasing night-time SUHII in all seasons for most cities suggest increasing trend in temperature in cities due to the impact of the rapid urbanisation, and thus, suggesting the influence of anthropogenic forcing on SUHII. This is also supported by the analysis of aerosols, night lights, precipitation and vegetation in the study regions. Therefore, this study shall aid planning and management of urban areas by giving insights about the effects of nature and intensity of development, land cover and land use mix and the structure of cities on SUHII.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.UCLIM.2022.101230", "year": 2022, "title": "Distinctive roles of two-and three-dimensional urban structures in surface urban heat islands over the conterminous United States", "abstract": "In this study, we investigated how seasonal and diurnal surface urban heat islands (SUHIs) vary with two- and three-dimensional (2D and 3D) urban structure parameters (USPs) and climate settings. Additionally, whether and how 2D and 3D USPs influenced the seasonal hysteresis between SUHIs and background temperatures were explored using remote sensing for 203 cities over the conterminous US. Results show that urban areas with high impervious surface coverage (70%) were colder in summer than surrounding rural areas in dry climates. Moreover, the cooling efficiency of vegetation in dry climates was about two times higher than that in wet climates. A hump-shaped relation between sky view factor (SVF) and SUHIs was observed; in regions with low SVF (e.g., SVF ", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1016/J.ENVPOL.2016.04.055", "year": 2016, "title": "Estimation of anthropogenic heat emissions in urban Taiwan and their spatial patterns", "abstract": "High energy consumption in the urban environment impacts the urban surface energy budget and causes the emission of anthropogenic heat fluxes (AHFs) into the atmosphere. AHFs vary over time and space. Thus, a reliable estimation of AHF is needed for mesoscale meteorological modeling. This study used a statistical regression method to estimate the annual mean gridded AHF with high spatial (1-km) resolution. Compared with current methods for AHF estimation, the statistical regression method is straightforward and can be easily incorporated with meteorological modeling. AHF of the highly populated urban areas in Taiwan were estimated using data from the anthropogenic pollutant emission inventory of CO and NOx for year 2010. Over 40% of the total AHF values in Taiwan main island fell within the range of 1040 Wm2. When the study domain was confined to urban land, the percentage contributions from AHF values were increased, with over 68% of the total AHF values within the range of 1040 Wm2. AHF values > 40 Wm2 were more abundant in the Southern region, followed by the Central and Northern regions. An assessment of the heat emissions by the large scale urban consumption of energy (LUCY) model revealed that the mean AHFs are reasonably close to those produced while the maximum AHFs are underestimated. The results obtained evidence the impact of spatial distribution of land use types, particularly population densities, main highways and industries on AHF generation in Taiwan.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/IJERPH19116579", "year": 2022, "title": "Effects of COVID-19 Restriction Policies on Urban Heat Islands in Some European Cities: Berlin, London, Paris, Madrid, and Frankfurt", "abstract": "The present study investigates the effects of policies restricting human activities during the COVID-19 epidemic on the characteristics of Night Land Surface Temperature (NLST) and Night Urban Heat Islands (NUHI) in five major European cities. In fact, the focus of this study was to explore the role of anthropogenic factors in the formation and intensity of NUHI. The effect of such factors was uncontrollable before the COVID-19 outbreak on the global scale and in a real non-laboratory environment. In this study, two indices, the concentration of Nitrogen dioxide (NO2) and Nighttime Lights (NL), were used as indicators of the number of anthropogenic activities. The data were collected before the COVID-19 outbreak and after its prevalence in 20192020. A Paired samples t-test and a Pearson correlation were used to examine the differences or significant relationships between the variables and indicators studied throughout the two periods. The results of the study confirmed a direct and significant relationship between NO2 and NL indices and the NUHI and NLST variables; however, using strict restrictions during the COVID-19 pandemic, the NO2 and NL indices decreased seriously, leading to significant changes in the characteristics of the NUHI and NLST in the five cities. This study has some implications for urban planners and politicians, e.g., the environmental impacts of changing the nature and level of anthropogenic activities can greatly affect the pattern and intensity of the Urban Heat Islands (UHIs) (as a serious environmental challenge).", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1002/2017JD027501", "year": 2018, "title": "Modeling Impacts of Urbanization and Urban Heat Island Mitigation on Boundary Layer Meteorology and Air Quality in Beijing Under Different Weather Conditions", "abstract": "Beijing has experienced a rapid urbanization in the last few decades and has been suffering from serious air pollution during recent years. The Weather Research and Forecasting-Chem model is used to quantify the effects of urbanization on regional climate and air quality and those of urban heat island (UHI) mitigation strategy on urban air quality in Beijing, with a special focus on the impacts under different weather conditions (heat waves in summer and polluted days in winter). The modification of rural land use into urban impervious surface significantly increases 2-m temperature (T2) and planetary boundary layer height but decreases 2-m relative humidity (RH2) and 10-m wind speed (WS10) in urban Beijing, which further leads to the increases in surface-layer O3 concentrations of 9.5 ppbv in summer and 1.8 ppbv in winter and the decreases in PM2.5 concentrations of 16.6 \u03bcg m-3 in summer and 26.2 \u03bcg m-3 in winter. Compared with normal days (clean days), the UHI intensity is enhanced by 11.1% during heat waves in summer (by 16.7% during polluted days in winter). Although increasing urban albedo is an effective mitigation strategy to decrease UHI intensity, it worsens the urban air quality. When the urban albedo increases from 0.2 to 0.85, the daily average PM2.5 concentrations are increased by 10.2 (6.1) \u03bcg m-3 in summer (in winter), and the daily maximum O3 concentrations are increased by 12.8 ppbv under heat waves in summer.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS14102478", "year": 2022, "title": "Long-Term Spatiotemporal Patterns and Evolution of Regional Heat Islands in the Beijing\u2013Tianjin\u2013Hebei Urban Agglomeration", "abstract": "With the continuous development of urbanization, the urban heat island (UHI) phenomenon is becoming increasingly prominent. Especially with the development of various large urban agglomerations and the shrinking distance between cities, the regional thermal environment has attracted extensive attention. Therefore, we used Modis land surface temperature (LST) data and employed least squares, standard deviation and spatial autocorrelation analysis methods to analyze the spatiotemporal patterns and characteristics of summer daytime regional urban heat islands (RHI) in the BeijingTianjinHebei (BTH) urban agglomeration. Our results indicated that the relative land surface temperature (RLST) in the southeastern part of BTH with a relatively high level of urbanization showed a significant and continuous upward trend. With the continuous development of the level of urbanization in the southeast, the center of gravity (GC) of RHI gradually moved to the southeast, and the development direction of RHI changed from northwestsoutheast to northeastsouthwest. The area transfer of RHI was concentrated in no change and little change, indicating that the evolution trend of RHI was relatively stable. The high-high aggregation areas were mainly located in the more developed areas in the southeast. In addition, the methods and results of this study can provide reasonable and effective insights into the future development and planning of the BTH.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1126/SCIADV.ABB9569", "year": 2021, "title": "Crowdsourced air temperatures contrast satellite measures of the urban", "abstract": "Satellites overestimate urban heat islands.\r\n , \r\n The ubiquitous nature of satellite data has led to an explosion of studies on the surface urban heat island (SUHI). Relatively few have simultaneously used air temperature measurements to compare SUHI with the canopy UHI (CUHI), which is more relevant to public health. Using crowdsourced citizen weather stations (>50,000) and satellite data over Europe, we estimate the CUHI and SUHI intensity in 342 urban clusters during the 2019 heat wave. Satellites produce a sixfold overestimate of UHI relative to station measurements (mean SUHI 1.45C; CUHI 0.26C), with SUHI exceeding CUHI in 96% of cities during daytime and in 80% at night. Using empirical evidence, we confirm the control of aerodynamic roughness on UHI intensity, but find evaporative cooling to have a stronger overall impact during this time period. Our results support urban greening as an effective UHI mitigation strategy and caution against relying on satellite data for urban heat risk assessments.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1111/1745-5871.12579", "year": 2023, "title": "Spatial and temporal dynamics of the urban heat island effect in a small Brazilian city", "abstract": "This study examined the spatial and temporal patterns of the canopy layer urban heat islands (UHIUCL) in a small city in southeastern Brazil using the local climate zone (LCZ) system. We analysed the influence of weather conditions, LCZs characteristics, and local surface relief on the UHIUCL magnitudes. Mobile traverses were used to measure air temperatures during representative nights of wet and dry seasons. Daily maximum magnitudes were observed in compact classes (LCZs 3 and 7) under ideal weather conditions (dry, clear skies, and calm) and higher anthropogenic heat release (weekdays). Seasonal effects on LCZ thermal differences were negligible. The peripheral landscapes were warmer than the city centre in both seasons. Among the warmer areas in the city, magnitudes in compact LCZs 3 and 7 were consistently higher than in LCZ 6. In general, representative sites of the main 'built' LCZs in the study area exhibit similar inter\u2011zone temperature patterns to those reported for cities of different sizes from tropical and midlatitude regions. Thermal contrasts of \u0394TLCZ 3 \u2212 D in the study area reveal significant evidence that small cities can have as strong heat islands as bigger cities. These findings highlight the importance of the LCZ system to identify the main controlling factors driving such thermal differences and the need to extend the application of this approach in other South American cities to yield systematic data of UHIUCL for urban planning given the coming challenges of climate change over the region.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1088/2515-7620/AB121D", "year": 2019, "title": "Decline in surface urban heat island intensity in India during heatwaves", "abstract": "Heatwaves cause human mortality around the world and are projected to rise in the future. Despite the influence of urban heat island (UHI) on heatwaves, the role of UHI on heatwave intensification in urban areas in India remains unrecognized. Here using in situ, satellite observations, and model simulations, we show that urban areas in India do not intensify heatwaves. The frequency of hot-days has significantly (p-value <0.05) increased in urban areas during 1951-2016. The frequency of hot-nights has also increased in the majority of urban areas in India except those located in Indo-Gangetic Plain (IGP). We show that a decline in the frequency of hot-nights (-4.5 \u00b1 1.6 hot-nights) in IGP during 1951-2016 is mainly due to intensive irrigation in the region. We confirm the influence of irrigation on land surface temperature (LST) over IGP using simulations from Community Land Model (CLM4). Our results show that Surface Urban Heat Island (SUHI) intensity in major urban areas in India declines during heatwaves both during the day (-0.3 \u00b1 0.7 \u00b0C) and night (-0.3 \u00b1 0.4 \u00b0C) from the reference SUHIs. Surrounding non-urban areas (44.5 \u00b1 5.5 \u00b0C) are warmer than urban areas (43.7 \u00b1 6.8 \u00b0C) during heatwaves due to the absence of vegetation. Our results have implications for policy related to health impacts during heatwaves.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.134579", "year": 2020, "title": "Trends and drivers of land surface temperature along the urban-rural gradients in the largest urban agglomeration of China", "abstract": "Urban heat magnitude and effects may represent harbingers of future climate change and the urban-rural gradients provide a unique natural laboratory for identifying both problems and solutions to climate change mitigation and adaptation. Here, we explored the trends and driving forces of land surface temperature (LST) along the urban-rural gradients of 26 cities in the largest urban agglomeration of China, the Yangtze River Delta Urban Agglomeration, using MODIS LST data combined with urban intensity, background climate, vegetation greenness, landscape structure, albedo, population and gross domestic product (GDP). We found that LST generally increased with increasing urban intensity along the urban-rural gradients while with large diurnal and seasonal variability. Large variability also existed between the maximum and minimum LST within the same urban intensity (e.g., 6.4 C), suggesting cities themselves provide ready-made solutions (minimum) to resolving heat island problems. However, the range of LST within the same intensity decreased with the urban intensity and narrowed drastically when the intensity reached certain thresholds (e.g., 5887% varying with season, time of day, and city), implying that the space for climate mitigation is very limited once the urbanization intensity exceeds critical thresholds. The roles of landscape structure (composition and configuration) for greenspace and urban land have become increasingly important in driving the variation of LST with increasing urban intensity from low (20%30%), middle (45%55%) to high (70%80%), clearly indicating that subtle urban landscape designing, such as less aggregated urban configuration and more irregular greenspace shape are effective strategies to mitigate climate change in highly urbanized areas and cities themselves already provide such vivid demonstrations for us to find and learn.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.GLOENVCHA.2021.102441", "year": 2021, "title": "Global long-term mapping of surface temperature shows intensified intra-city urban heat island extremes", "abstract": "Surface temperatures are generally higher in cities than in rural surroundings. This phenomenon, known as Surface Urban Heat Island (SUHI), increases the risk of heat-related human illnesses and mortality. Past global studies analysed this phenomenon aggregated at city scale or over seasonal and annual time periods, while human impacts strongly depend on shorter term heat stress experienced locally. Here we develop a global long-term high-resolution dataset of daytime SUHI, offering an insight into the spacetime variability of the urbanrural temperature differences which is unprecedented at global scale. Our results show that across urban areas worldwide over the period 20032020, 3-day SUHI extremes are on average more than twice as high as the warm-season median SUHI, with local exceedances up to 10 K. Over this period, SUHI extremes have increased more rapidly than warm-season medians, and averaged worldwide are now 1.04 K or 31% higher compared to 2003. This can be linked with increasing urbanisation, more frequent heatwaves, and greening of the earth, processes that are all expected to continue in the coming decades. Within many cities there are hotspots where extreme SUHI intensity is 1015 K higher compared to relatively cooler city parts. Given the limited human adaptability to heat stress, our results advocate for mitigation strategies targeted at reducing SUHI extremes in the most vulnerable and exposed city neighbourhoods.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1175/JCLI-D-21-0767.1", "year": 2022, "title": "Changes in the length of the season with favorable environmental conditions for tropical cyclones in the North Atlantic basin during the last 40 years", "abstract": "Abstract Analyses of two high-resolution reanalysis products show high values of hurricane potential intensity (PI) are becoming more frequent and covering a larger area of the Atlantic, which is consistent with the lengthening of the tropical cyclone season previously reported. These changes are especially pronounced during the early months of the storm season (May to July) in subtropical latitudes. The western subtropical Atlantic features increases in mean PI as well as the areal coverage and frequency of high PI throughout the storm season; the length of the season with high PI has grown since 1980. The number of days with low vertical wind shear increases in the tropical North Atlantic during the early and middle months of the storm season, but trends are mixed and generally insignificant elsewhere. A thermodynamic parameter measuring the ratio of mid-level entropy deficits to the strength of surface fluxes that work to eliminate them, is sensitive to the choice of the pressure level(s) used to calculate its value in the boundary layer, as well as to subtle differences in temperature and humidity values near the surface in different reanalysis datasets, leading to divergent results in metrics like the ventilation index that depend on its value. Projections from a high-resolution simulation of the remainder of the 21st century show the number of days with high PI is likely to continue increasing in the North Atlantic basin, with trends especially strong in the western subtropical Atlantic during the early and late months of the season.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2022JD036818", "year": 2022, "title": "A New Perspective on the Development of the Great Arctic Cyclone in August 2012", "abstract": "The evolutionary process of \"The Great Arctic Cyclone (AC) of August 2012\" (hereafter named as AC2) was investigated by using the Arctic System Reanalysis version 2 data, from a new perspective of two cyclones' merging. The evolution of AC2 was affected by the merging process with a pre-existing AC (hereafter named as AC1) at lower-levels, and the impact of the two tropopause polar vortices (TPVs). The AC2's development showed a slowdown at the early stage of merging (before 00 UTC 5), and a rapid intensification at the later stage (after 00 UTC 5). The diagnostic results based on Zwack-Okossi equation showed that, at the early stage of merging when two TPVs had not merged, despite AC2's intensification was favored by vorticity advection provided by the upper-level jet stream, the warm advection supporting AC2's development, which was prevented by TPV2. AC2 weakened due to the joint influences of cold advection induced by the cold core beneath the TPV2 and AC1's cyclonic circulation at lower-levels. At the later stage of merging, AC2 rapidly intensified due to the joint influences of warm advection produced by the warm air advected from warm core above the merged TPV by the upper-level jet stream, and the warm advection induced by enhanced lower-level baroclinicity near the warm front. Diabatic heating near the upper- and lower-level fronts also played an important role in promoting AC2's development through its whole time.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/JAMC-D-20-0190.1", "year": 2021, "title": "CYGNSS observations and analysis of low-latitude extratropical cyclones", "abstract": "Abstract Latent and sensible heat fluxes over the oceans are believed to play an important role in the genesis and evolution of marine-based extratropical cyclones (ETCs) and affect rapid cyclogenesis. Observations of ocean surface heat fluxes are limited from existing in situ and remote sensing platforms, which may not offer sufficient spatial and temporal resolution. In addition, substantial precipitation frequently veils the ocean surface around ETCs, limiting the capacity of spaceborne instruments to observe the surface processes within maturing ETCs. Although designed as a tropics-focused mission, the Cyclone Global Navigation Satellite System (CYGNSS) can observe ocean surface wind speed and heat fluxes within a notable quantity of low-latitude extratropical fronts and cyclones. These observations can assist in understanding how surface processes may play a role in cyclogenesis and evolution. This paper illustrates CYGNSSs capability to observe extratropical cyclones manifesting in various ocean basins throughout the globe and shows that the observations provide a robust sample of ETCs winds and surface fluxes, as compared with a reanalysis dataset.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS9090365", "year": 2018, "title": "Contributions of Atmospheric Transport and Rain-Vapor Exchange to", "abstract": "Coastal mangroves are increasingly recognized as valuable natural resources and important sites of water and carbon exchange. In this study, we examine atmospheric water cycling in the boundary layer above a coastal mangrove forest in southern China. We collected site observations of isotopic ratios in water vapor and precipitation along with core meteorological variables during July 2017. Our evaluation of these data highlights the influences of large-scale atmospheric transport and rainvapor exchange in the boundary layer water budget. Rainvapor exchange takes different forms for different types of rainfall events. The evolution of isotopic ratios in water vapor suggests that substantial rain recycling occurs during the passage of large-scale organized convective systems, but that this process is much weaker during rainfall associated with less organized events of local origin. We further examine the influences of large-scale transport during the observation period using a Lagrangian trajectory-based moisture source analysis. More than half (63%) of the boundary layer moisture during the study period traced back to the South China Sea, consistent with prevailing southerly to southwesterly flow. Other important moisture sources included mainland Southeast Asia and the Indian Ocean, local land areas (e.g., Hainan Island and the Leizhou Peninsula), and the Pacific Ocean. Together, these five regions contributed more than 90% of the water vapor. The most pronounced changes in isotopic content due to large-scale transport during the study period were related to the passage of Tropical Storm Talas. The outer rain bands of this tropical cyclone passed over the measurement site on 1517 July, causing a sharp reduction in the heavy isotopic content of boundary layer water vapor and a substantial increase in deuterium excess. These changes are consistent with extensive isotopic distillation and rainvapor exchange in downdrafts associated with the intense convective systems produced by this storm.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.2112/JCOASTRES-D-21-00025.1", "year": 2021, "title": "Comparing Tropical Cyclone and King Tide Impacts on a South Carolina Coastal Dune System", "abstract": "Harris, M.E. and Ellis, J.T., 2021. Comparing tropical cyclone and king tide impacts on a South Carolina coastal dune system. Journal of Coastal Research, 37(5), 923932. Coconut Creek (Florida), ISSN 0749-0208.Coastal populations face an ever-growing threat as natural hazards increase in frequency and magnitude. In South Carolina, king tides (abnormally high tides) responsible for coastal flooding have increased by 126% between 2014 and 2019. King tides present an evolving threat as sea levels rise, yet the implications for coastal dune response have not been investigated. This study compares the geomorphic impacts from king tides to two tropical cyclones on a South Carolina barrier island during four time periods (TPs): Hurricanes Florence (TP1) and Michael (TP2) and two subsequent periods (TP3 and TP4) with king tides but devoid of tropical cyclone activity. Florence resulted in the greatest average change to the dunes, with normalized volumes (nv) equivalent to 11.6 m3/d. During Michael, the average change rate was nv = 1.5 m3/d. Dune changes during TP3 and TP4 averaged nv = 1.7 m3/d and nv = 2.3 m3/d, respectively. The reduction rate during nonstorm conditions is indicative of the erosive potential of king tides. The erosive potential should be further investigated in conjunction with king tide magnitude and frequency. Smaller, more pervasive coastal hazards, such as king tides, should be more strongly considered, in addition to larger singular events, such as tropical cyclones, when investigating the geomorphic change of coastal dune systems.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1201/9780429075872-9", "year": 2020, "title": "Applying Landsat Products to Assess the Damage and Resilience of Mangroves from Hurricanes", "abstract": "", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1175/JAMC-D-21-0074.1", "year": 2021, "title": "On the Relationship between CYGNSS Surface Heat Fluxes and the Life Cycle of Low-Latitude Ocean Extratropical Cyclones", "abstract": "Abstract Surface latent and sensible heat fluxes are important for extratropical cyclone evolution and intensification. Because extratropical cyclone genesis often occurs at low latitudes, Cyclone Global Navigation Satellite System (CYGNSS) surface latent and sensible heat flux retrievals are composited to provide a mean picture of their spatial distribution in low-latitude oceanic extratropical cyclones. CYGNSS heat fluxes are not affected by heavy precipitation and offer observations of storms with frequent revisit times. Consistent with prior results obtained for cyclones in the Gulf Stream region, the fluxes are strongest in the wake of the cold fronts and are weakest to negative in the warm sector in advance of the cold fronts. As cyclone strength increases or mean precipitable water decreases, the maximum in surface heat fluxes increases while the minimum decreases. This affects the changes in fluxes during cyclone intensification: the post-cold-frontal surface heat flux maximum increases as a result of the increase in near-surface winds. During cyclone dissipation, the fluxes in this sector decrease because of the decrease in winds and in temperature and humidity contrast. The warm-sector minimum decreases throughout the entire cyclone lifetime and is mostly driven by seaair temperature and humidity contrast changes. However, during cyclone dissipation, the surface heat fluxes increase along the cold front in a narrow band to the east, independent from changes in the cyclone characteristics. This result suggests that, during cyclone dissipation, energy transfers from the ocean to the atmosphere are linked to frontal processes in addition to synoptic-scale processes.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2020GL091478", "year": 2021, "title": "Satellite Observations of the Sea Surface Salinity Response to Tropical", "abstract": "Decade-long satellite sea surface slinity (SSS) observations show that rain dilution prevails in wakes of tropical depressions (\u223c-0.1 pss) and tropical storms (\u223c-0.05 pss) on the left (right) side of Northern (Southern) Hemisphere storms. For stronger storms, the rain-induced dilution is dominated by the saltier water entrainment, leading to surface median salinification of 0.3 pss for the most intense storms, peaking on the right-hand side at around twice the maximum wind radius. The magnitude of the salty wake increases for stronger slowly moving storms. The vertical salinity gradient in the upper ocean is a key factor explaining the geographic distribution of the SSS response. A striking example is the systematic mixing of fresh near-surface river plume waters with saltier subsurface waters. It is also found that barrier layers lead to saltier and warmer storm wakes compared to wakes produced over barrier layer free areas.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.UCLIM.2022.101224", "year": 2022, "title": "Strengthened tropical cyclones and higher flood risk under compound effect of climate change and urbanization across China's Greater Bay Area", "abstract": "Climate change and urbanization will further exacerbate tropical cyclones (TCs) causing severer flooding especially in coastal urbanized areas. In this study, the compound effects of climate change and urbanization on organized TC and its flood risk across the Guangdong-Hong Kong-Macau Greater Bay Area (GBA) were explored and future projections of 10 models in different Shared Socioeconomic Pathways (SSPs) and Representative Concentration Pathways (RCPs) in Coupled Model Intercomparison Project 6 (CMIP6). The typical TC named Ewiniar that caused tremendous rainfall and flooding over GBA is taken as a case. We found that future TC will be exacerbated with rainfall band shifting inland and covering larger areas compared to the current scenario due to climate change and urbanization, and rainfall amount in the central rainfall band increases by 24% and 28% under SSP2-RCP4.5 and SSP5-RCP8.5, respectively. Due to the land-atmosphere interactions, future actual direct runoff increased by 7.91%15.53% during the TC Ewiniar under SSP2-RCP4.5 and SSP5-RCP8.5, leading to further expansion of the area marked with the highest flood risk (24% and 39%, respectively). Our study highlights the adverse compound effect of climate change and urbanization on TC and flood risk, helping to develop TC-related disaster prevention and mitigation policies.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 9, "name": "Floods" } ] }, { "doi": "10.1016/J.MARENVRES.2011.02.008", "year": 2011, "title": "Physical and biological response of the Arabian Sea to tropical cyclone Phyan and its implications", "abstract": "The response to the tropical cyclone Phyan, which developed in the eastern Arabian Sea during 911 November 2009, was rapid cooling of sea surface temperature (SST), enhancement of chlorophyll a and two-fold increase in net primary productivity (NPP). Cooling of SST was immediate in response to the strong wind-mixing, and the subsequent upward Ekman pumping sustained the cooling even after the dissipation of Phyan. The biological response mediated by the upward Ekman pumping driven vertical transport of subsurface nutrient showed a time lag of 34 days. The CO2 flux to the atmosphere associated with Phyan was 0.123 Tg C, which accounted for 85% of the total out-gassing from the eastern Arabian Sea during November. Thus, an increased occurrence of cyclones in a warming environment will lead to an enhanced biomass production and also increase in CO2 out-gassing.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/MWR-D-19-0341.1", "year": 2020, "title": "The impacts of horizontal grid spacing and cumulus parameterization on subseasonal prediction in a global convection-permitting model", "abstract": "Abstract\r\n \r\n A novel Bayesian Monte Carlo integration (BMCI) technique was developed to retrieve geophysical variables from satellite microwave radiometer data in the presence of tropical cyclones. The BMCI technique includes three steps: generating a stochastic database, simulating satellite brightness temperatures using a radiative transfer model, and retrieving geophysical variables such as profiles of temperature, relative humidity, and cloud liquid and ice water content from real observations. The technique also provides uncertainty estimates for each retrieval and can output the error covariance matrix of selected parameters. The measurements from the Advanced Technology Microwave Sounder (ATMS) on board\r\n Suomi National Polar-Orbiting Partnership\r\n (\r\n Suomi NPP\r\n ) and the Global Precipitation Measurement (GPM) Microwave Imager (GMI) were used as input. A new technique was developed to correct the ATMS and GMI observations for the beam-filling effect, which is due to small-scale variability of precipitation and clouds when compared with the instrument footprint and also the nonlinear relation between the brightness temperature and precipitation. In addition, the assimilation of the BMCI retrievals into the NASA GEOS model is discussed for Hurricane Maria. The results show that assimilating the BMCI retrievals can influence the dynamical features of the cyclone, including a stronger warm core, a symmetric eye, and vertically aligned wind columns. Two possible factors that may limit the impact of the BMCI retrievals include 1) the resolution of the model (about 25 km), which was too coarse to show the potential of the BMCI data in improving the representation of tropical storms in the model forecast, and 2) the data assimilation system not being able to consider vertically correlated observation errors.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1175/MWR-D-18-0295.1", "year": 2019, "title": "The impact of the Amazon\u2013Orinoco River plume on enthalpy flux and air\u2013sea interaction within Caribbean Sea tropical cyclones", "abstract": "Abstract The influence of the AmazonOrinoco River plume in the Caribbean Sea on latent and sensible heat flux (enthalpy flux) and tropical cyclone (TC) intensity is investigated for Hurricanes Ivan (2004), Emily (2005), Dean (2007), and Felix (2007) using dropwindsonde data, satellite sea surface temperature (SST), and the SMARTS climatology. Relationships among enthalpy fluxes, ocean heat content relative to the 26C isotherm depth (OHC), and SST during storm passage are diagnosed. Results indicate that sea surface cooling in the river plume, a low-OHC region, is comparable to that in the warm eddy region, which has high OHC. An isothermal layer heat budget shows that upper-ocean cooling in the river plume can be explained predominantly by sea-to-air heat flux, rather than by entrainment flux from the thermocline. The latter two findings suggest that relatively large upper-ocean stratification in the plume regime limited entrainment cooling, sustaining SST and enthalpy flux. Inspection of atmospheric variables indicates that deep moderate wind shear is prevalent, and equivalent potential temperature is enhanced over the river plume region for most of these storms. Thus, sustained surface fluxes in this region may have provided warm, moist boundary layer conditions, which may have helped these storms to rapidly intensify even over relatively low-OHC waters and moderate shear. These findings are important because several Caribbean Sea TCs, including these cases, have been underforecast with respect to intensity and/or rapid intensifications, yet minimal upper-ocean observations exist to understand airsea interaction during TCs in the salinity-stratified AmazonOrinoco plume regime.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1029/2020JD033454", "year": 2020, "title": "Influence of Saharan dust on the large\u2010scale meteorological environment for development of tropical cyclone over North Atlantic Ocean Basin", "abstract": "The tropical cyclones (TCs) frequently occur in the North Atlantic Ocean Basin, which is adjacent to West Africa, the largest global source of atmospheric dust. However, few studies have conducted systematic observational research of how dust affects the genesis conditions of TCs at large scales which includes sea surface temperature (SST), vorticity, vertical wind shear, and specific humidity. This study focused on the period from June-September in the years 2000 to 2018 to investigate the horizontal and vertical distributions of aerosol optical depth (AOD) (dust) and meteorological parameters. Dust can be transported at 600 hPa upward and is mixed well within the troposphere over land, while it is mainly distributed in the lower troposphere over the ocean. The SST is significantly suppressed by dust due to direct radiation effects, but the atmospheric temperature is warmer at 20-40\u00b0W between 700 and 850 hPa. The vertical distributions of temperature and specific humidity are similar. Dust decreases specific humidity in the lower troposphere over the ocean, especially in high AOD regions, but enhances midlevel moisture. Dust heats the lower troposphere and favors the development of convection and positive vorticity at heights of approximately 800-1,000 hPa. The warming effect of dust on the lower atmosphere over land and the nearby oceans results in strengthened West African monsoons and vertical wind shear. Thus, dust suppresses the SST and low-level specific humidities and favors wind shear and positive relative vorticity, which further influence environmental conditions in the TC genesis region.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1134/S0097807821020172", "year": 2021, "title": "The Effect of Typhoon Goni on the Production Characteristics of Coastal Water in Posyet Bay, the Sea of Japan", "abstract": "The effect caused by the typhoon Goni in the coastal water of Posyet Bay, the Sea of Japan, is considered. In nearshore expeditions, profilograph SBE-19plus was used to measure the hydrological characteristics: water temperature and salinity, as well as the hydrobiological characteristics of the fluorescence of chlorophyll a and dyed dissolved organic matter a week after the passage of the typhoon. To reveal the effect of the typhoon on the ecosystem, the data measured after typhoon passage were compared with the appropriate characteristics obtained in the same season in about the same place a year before, when there was no typhoon. A high correlation was found to exist between chlorophyll a concentration and the input of fresh water from the continent. It was shown that the dyed dissolved organic matter is determined, in addition to the continental export, by autochthonous processes. The problem formulated in the study was solved with the involvement of satellite data, which reflected changes in the ecosystem in large water areas and suggested the conclusion that the changes caused by the typhoon shift the state of the coastal zone toward that of river estuaries.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1109/TGRS.2022.3161002", "year": 2022, "title": "First Quasi-Synchronous Hurricane Quad-Polarization Observations by C-Band Radar Constellation Mission and RADARSAT-2", "abstract": "This is the first presentation of quasi-synchronous spaceborne synthetic aperture radar (SAR) high-resolution images acquired from C-band Radar Constellation Mission (RCM) and RADARSAT-2 consisting of quad-polarization (HH + HV + VH + VV) wide-swath observations of Hurricane Epsilon. These measurements clearly show that the denoised HV- and VH-polarized normalized radar cross sections (NRCSs) have great consistency. NRCS values at HV- and VH-polarizations are more sensitive to wind speeds and less sensitive to incidence angles or wind directions than those at HH and VV for hurricane force winds. For large incidence angles and high wind speeds, the sensitivity of HH-polarized NRCS to wind speed is higher than that of VV. HH- and VV-polarized NRCSs gradually lose wind direction dependency at high winds. It is notable that the time interval between the two SAR acquisitions is only 3 min. This allows for a direct comparison of HV- and VH-polarized images to investigate the variations in high-resolution backscattering within the hurricane vortex, thereby revealing the most dynamical areas. An asymmetric dynamic is observed around the eye of Hurricane Epsilon, based on positive and negative differences (VHHV) in the western and eastern parts of the eye. The impacts of rain on quad-polarized NRCS are also examined using collocated rain rates from the Global Precipitation Mission (GPM) and wind speeds from the Soil Moisture Active Passive (SMAP). Significant rain-induced NRCS attenuations are about 1.7 dB for HH and VV, and 2.2 dB for HV and VH, when the rain rate is 20 mm/h. These attenuations are associated with rain-induced turbulence and atmospheric absorption. This work shows that the collocated RCM and RADARSAT-2 hurricane observations provide a unique analysis of synoptic and joint C-band measurements of the ocean surface in quad-polarization; this is noteworthy in view of preparations for the next generation of dual-polarization scatterometer (SCA) onboard second-generation meteorological operational satellite program (MetOp-SG).", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/ACP-18-5821-2018", "year": 2018, "title": "Aerosol midlatitude cyclone indirect effects in observations and high-resolution simulations", "abstract": "Abstract. Aerosolcloud interactions are a major source of uncertainty in inferring the climate sensitivity from the observational record of temperature. The adjustment of clouds to aerosol is a poorly constrained aspect of these aerosolcloud interactions. Here, we examine the response of midlatitude cyclone cloud properties to a change in cloud droplet number concentration (CDNC). Idealized experiments in high-resolution, convection-permitting global aquaplanet simulations with constant CDNC are compared to 13 years of remote-sensing observations. Observations and idealized aquaplanet simulations agree that increased warm conveyor belt (WCB) moisture flux into cyclones is consistent with higher cyclone liquid water path (CLWP). When CDNC is increased a larger LWP is needed to give the same rain rate. The LWP adjusts to allow the rain rate to be equal to the moisture flux into the cyclone along the WCB. This results in an increased CLWP for higher CDNC at a fixed WCB moisture flux in both observations and simulations. If observed cyclones in the top and bottom tercile of CDNC are contrasted it is found that they have not only higher CLWP but also cloud cover and albedo. The difference in cyclone albedo between the cyclones in the top and bottom third of CDNC is observed by CERES to be between 0.018 and 0.032, which is consistent with a 4.68.3 Wm2 in-cyclone enhancement in upwelling shortwave when scaled by annual-mean insolation. Based on a regression model to observed cyclone properties, roughly 60 % of the observed variability in CLWP can be explained by CDNC and WCB moisture flux.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1002/JOC.7416", "year": 2021, "title": "Tropical cyclone characteristics associated with extreme precipitation in the northern Philippines", "abstract": "The Philippines is exposed to tropical cyclones (TCs) throughout the year due to its location in the western North Pacific. While these TCs provide much-needed precipitation for the country's hydrological cycle, extreme precipitation from TCs may also cause damaging hazards such as floods and landslides. This study examines the relationship between TC extreme precipitation and TC characteristics, including movement speed, intensity and season, for westward-moving TCs crossing Luzon, northern Philippines. We measure extreme precipitation by the weighted precipitation exceedance (WPE), calculated against a 95th percentile threshold, which considers both the magnitude and spatial extent of TC-related extreme precipitation. WPE has a significant, moderate positive relationship with TC intensity with a non-significant, weak negative relationship with movement speed. When TCs are classified by intensity 1 day before landfall (or pre-landfall), Typhoons (1-min maximum sustained wind speed \u226564 knots) tend to yield higher WPE than non-Typhoons (<64 knots). On the other hand, when TCs are classified by pre-landfall speed, slow TCs (movement speed <11.38 knots) tend to yield higher WPE than fast TCs (movement speed \u226511.38 knots). However, the relationship between pre-landfall TC intensity and WPE is more pronounced during June-September while there is no significant difference between the WPE of the southwest monsoon (June-September) and northeast monsoon (October-December) seasons. These results suggest that it is important to consider the pre-landfall cyclone movement speed, intensity and season to anticipate extreme precipitation of incoming TCs. A decision table considering these factors is devised to aid in TC extreme precipitation forecasting.", "labels": [ { "id": 15, "name": "Severe Storms" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00382-021-05734-8", "year": 2021, "title": "Wet-to-dry climate shift of the Sichuan Basin during 1961-2010", "abstract": "The autumn precipitation over the Sichuan Basin (APSB) experienced a significant wet-to-dry shift around the mid-1980s during the 1961-2010 period. Thus, the dataset is divided into two subperiods, 1961-1985 (P1) and 1986-2010 (P2), which are denoted as the wet period and dry period, respectively. The possible mechanisms accounting for the wet-to-dry shift in the APSB are investigated using both observational data and a baroclinic atmospheric model. Analysis shows that the sea surface temperature (SST) in the tropical Indian-western Pacific (TIWP) regions displays continuous warming during the period under examination, which may intensify the ascent motion over the warm pool and favor the descent motion over the Sichuan Basin. Meanwhile, the Gill-type atmospheric response to anomalous TIWP warm SST is accompanied by anomalous northerly winds prevailing over central and Southwest China. Both the intensified descent motion and anomalous northerly winds over central and Southwest China favor the switch to dry conditions in the APSB. Further analysis shows that the decadal changes in the North Atlantic SST lead to an atmospheric wave pattern prevailing over the extratropical Eurasian continent. An anomalous cyclone over central-eastern Eurasia, which is one component of the wave pattern, is accompanied by significant northerly winds penetrating southward to central China. These northerly winds can cause more-than-normal snow cover around Lake Baikal, which may in turn modulate the atmospheric circulation through positive feedback and therefore result in intensified northerly winds, favorable for the switch to the anomalous dry state of the APSB.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/NHESS-22-213-2022", "year": 2022, "title": "Precipitation stable isotopic signatures of tropical cyclones in Metropolitan Manila, Philippines, show significant negative isotopic excursions", "abstract": "Abstract. Tropical cyclones have devastating impacts on the environment, economies, and societies and may intensify in the coming decades due to climate change. Stable water isotopes serve as tracers of the hydrological cycle, as isotope fractionation processes leave distinct precipitation isotopic signatures. Here we present a record of daily precipitation isotope measurements from March 2014 to October 2015 for Metropolitan Manila, a first-of-a-kind dataset for the Philippines and Southeast Asia. We show that precipitation isotopic variation at our study site is closely related to tropical cyclones. The most negative shift in 18O values (13.84 ) leading to a clear isotopic signal was caused by Typhoon Rammasun, which directly hit Metropolitan Manila. The average 18O value of precipitation associated with tropical cyclones is 10.24 , whereas the mean isotopic value for rainfall associated with non-cyclone events is 5.29 . Further, the closer the storm track is to the sampling site, the more negative the isotopic values are, indicating that in situ isotope measurements can provide a direct linkage between isotopes and typhoon activities in the Philippines.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.5194/NHESS-22-3285-2022", "year": 2022, "title": "Sensitivity of simulating Typhoon Haiyan (2013) using WRF: the role of cumulus convection, surface flux parameterizations, spectral nudging, and initial and boundary conditions", "abstract": "Abstract. Typhoon (TY) Haiyan was one of the most intense and highly\ndestructive tropical cyclones (TCs) to affect the Philippines. As such, it\nis regarded as a baseline for extreme TC hazards. Improving the simulation\nof such TCs will not only improve the forecasting of intense TCs but will\nalso be essential in understanding the potential sensitivity of future\nintense TCs with climate change. In this study, we investigate the effects\nof model configuration in simulating TY Haiyan using the Weather Research\nForecasting (WRF) Model. Sensitivity experiments were conducted by\nsystematically altering the choice of cumulus schemes, surface flux\noptions,\nand spectral nudging. In addition to using the European Centre for\nMedium-Range Weather Forecasts Reanalysis fifth-generation (ERA5) single\nhigh-resolution realization as initial and boundary conditions, we also\nused 4\nof the 10 lower-resolution ERA5 data assimilation system (EDA) ensemble\nmembers as initial and boundary conditions. Results indicate a high level\nof\nsensitivity to cumulus schemes, with a trade-off between using\nKainFritsch and Tiedtke schemes that have not been mentioned in past\nstudies of TCs in the Philippines. The Tiedtke scheme simulates the track\nbetter (with a lower mean direct positional error, DPE, of 33 km), while\nthe KainFritsch scheme produces stronger intensities (by 15 hPa minimum\nsea level pressure). Spectral nudging also resulted in a reduction in the\nmean DPE by 20 km, and varying the surface flux options resulted in the\nimprovement of the simulated maximum sustained winds by up to\n10 m s1. Simulations using the EDA members initial and boundary\nconditions revealed low sensitivity to the initial and boundary conditions,\nhaving less spread than the simulations using different parameterization\nschemes. We highlight the advantage of using an ensemble of cumulus\nparameterizations to take into account the uncertainty in the track and\nintensity of simulating intense tropical cyclones.", "labels": [ { "id": 15, "name": "Severe Storms" } ] }, { "doi": "10.1016/J.EPSL.2021.117104", "year": 2021, "title": "Zircon as a recorder of contrasting magma recharge and eruptive recurrence patterns", "abstract": "Contrasting Late PleistoceneHolocene eruptive behavior observed for Mt. Hasan and Mt. Erciyes, two neighboring stratovolcanic complexes in Central Anatolia, Turkey, poses general questions on the size and nature of magma systems underlying active volcanoes. Here, we complement UThPb zircon rim and interior crystallization ages for >1000 crystals from these volcanoes with trace element analyses on the same spots to unravel their magmatic histories. Thermochemical modeling of zircon crystallization is applied to quantify contrasting magma recharge and storage regimes. Both Mt. Hasan and Mt. Erciyes are characterized by protracted magmatic and volcanic activity since the Middle Pleistocene that is evident from individual crystals and crystal populations. However, zircon records contrasting thermochemical evolutions for both systems: Mt. Hasan with a history of recurrent eruptions throughout the Late Pleistocene exhibits comparatively narrow ranges of Ti-in-zircon crystallization temperatures and differentiation indices such as Zr/Hf ratios as well as Eu anomalies (Eu/Eu*) over the last ca. 300 ka. On the contrary, these parameters fluctuate over broader ranges for Mt. Erciyes, where relatively primitive zircon interiors nucleated during two major eruptive activity phases at ca. 10585 and ca. 9 ka, whereas zircon rims evolved to more differentiated compositions during the protracted eruptive lull in between. The contrasting zircon record is interpreted to mirror a protracted thermochemical steady-state of the Mt. Hasan magma system, but fluctuating conditions in Mt. Erciyes due to recharge rate variations. Zircon ages are modeled with integrated magma recharge rates of 10.5 km3/ka for Mt. Hasan, but only 0.1 km3/ka for Mt. Erciyes, indicating warm magma storage under eruptible conditions for Mt. Hasan, but cold magma storage below the rheological lockup temperature for Mt. Erciyes. The smaller volume of the Mt. Erciyes subsurface plumbing system contrasts with its larger edifice volume, suggesting that the volcano has reached a waning stage where episodically intensified magma recharge can trigger violent eruptions. The early Holocene resurgence of Mt. Erciyes may be in response to glacial unloading, whereas the peak-stage Mt. Hasan system may be less responsive to changes in magma recharge due to thermal buffering by a voluminous magma reservoir.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-21-14871-2021", "year": 2021, "title": "Changes in stratospheric aerosol extinction coefficient after the 2018", "abstract": "Abstract. Stratospheric aerosols are an important component of the climate system. They not only change the radiative budget of the Earth but also play an\nessential role in ozone depletion. These impacts are particularly noticeable after volcanic eruptions when SO2 injected with the eruption reaches the stratosphere, oxidizes, and forms stratospheric aerosol. There have been several studies in which a volcanic eruption plume and the associated radiative forcing were analyzed using climate models and/or data from satellite measurements. However, few have compared vertically and temporally resolved volcanic plumes using both measured and modeled data. In this paper, we compared changes in the stratospheric aerosol loading after the 2018 Ambae eruption observed by satellite remote sensing measurements and simulated by a global aerosol model. We use vertical profiles of the aerosol extinction coefficient at 869 nm retrieved at the Institute of Environmental Physics (IUP) in Bremen from OMPS-LP (Ozone Mapping and Profiling Suite Limb Profiler) observations. Here, we present the retrieval algorithm and a comparison of the obtained profiles with those from SAGE III/ISS (Stratospheric Aerosol and Gas Experiment III on board the International Space Station). The observed differences are within 25 % for most latitude bins, which indicates a reasonable quality of the retrieved limb aerosol extinction product. The volcanic plume evolution is investigated using both monthly mean aerosol extinction coefficients and 10 d averaged data. The measurement results were compared with the model output from MAECHAM5-HAM (ECHAM for short). In order to simulate the eruption accurately, we use SO2 injection estimates from OMPS and OMI (Ozone Monitoring Instrument) for the first phase of eruption and the TROPOspheric Monitoring Instrument (TROPOMI) for the second phase. Generally, the agreement between the vertical and geographical distribution of the aerosol extinction coefficient from OMPS-LP and ECHAM is quite remarkable, in particular, for the second phase. We attribute the good consistency between the model and the measurements to the precise estimation of injected SO2 mass and height, as well as to the nudging to ECMWF ERA5 reanalysis data. Additionally, we compared the radiative forcing (RF) caused by the increase in the aerosol loading in the stratosphere after the eruption. After accounting for the uncertainties from different RF calculation methods, the RFs from ECHAM and OMPS-LP agree quite well. We estimate the tropical (20 N to 20 S) RF from the second Ambae eruption to be about 0.13 W m2.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.QUASCIREV.2019.03.030", "year": 2019, "title": "Volcanic eruption eye-witnessed and recorded by prehistoric humans", "abstract": "Human footprints in hydrovolcanic ash near Cakallar volcano (Kula, Western Turkey) were discovered in 1968. A nearby pictograph interpreted as depicting Cakallar volcano would define it as the oldest site where humans demonstrably eye-witnessed a volcanic eruption and possibly artistically recorded it. Despite Cakallar's volcanological and cultural importance, its eruption age has remained controversial. Here, two independent dating methods, cosmogenic 36Cl and combined U-Pb and (U-Th)/He zircon (ZDD) geochronology, yielded the first internally consistent eruption ages controlled by detailed volcanostratigraphic mapping. Concordant 36Cl ages of 4.7 0.6 ka (errors 1) were obtained for a cone-breaching lava flow. ZDD ages for crustal xenoliths from scoria deposits directly overlying the footprints yielded an age of 4.7 0.7 ka. This firmly places the Cakallar eruption and prehistoric human footprints, and plausibly the rock art, into the Bronze Age, reinforcing the notion that prehistoric artwork recorded natural events.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.RSE.2022.113211", "year": 2022, "title": "Multispectral discrimination of spectrally similar hydrothermal minerals in mafic crust: A 5000 km2 ASTER alteration map of the Oman\u2013UAE ophiolite", "abstract": "Multispectral remote sensing of hydrothermal alteration in volcanogenic massive sulfide (VMS) ore systems in mafic crust is relatively uncommon, in part due to the short-wave infrared spectral similarity of several key alteration minerals: epidote, chlorite, actinolite, and serpentine. In this study, we developed regional mosaic generation and classification workflows for Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) imagery to discriminate these minerals over the entire crust of the Semail ophiolite (OmanUAE). Spectral discrimination was achieved through adaptation of the ASTER (pre-)processing workflow to the specific mapping targets, available datasets, and location of this study. Necessary steps included the pre-selection of ASTER scenes without residual atmospheric water features, mosaic normalization based solely on overlapping target outcrops, correcting cross-mosaic ramp errors, and alteration map classification based on image-derived reference data. The resulting alteration map, validated through comparison with field mapping and sampling, is the most areally extensive continuous survey of hydrothermal alteration yet presented for oceanic crust, providing a renewed framework for research and mineral exploration of Earth's largest ophiolite. Our map confirms that the vast majority of the upper oceanic crust is regionally altered to a spilite type secondary mineral assemblage. Localized areas of epidosite alteration, marking focused hydrothermal flow paths, are confined to the upper oceanic crust, whereas areas of previously unrecognized but intense actinolite alteration are common in both the lower and upper oceanic crust. Our methodological developments expand the standard considerations necessary for regional geological mapping using infrared image mosaics. They further demonstrate the underappreciated capability of multispectral data for mapping spectrally similar rock types. Although the specifics of the method are necessarily optimized for the OmanUAE ophiolite, re-optimization based on local reference data should allow similar results to be achieved in other well-exposed mafic-hosted VMS districts.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1007/S00445-022-01559-3", "year": 2022, "title": "Volcanic effects on climate: recent advances and future avenues", "abstract": "Volcanic eruptions have long been studied for their wide range of climatic effects. Although global-scale climatic impacts following the formation of stratospheric sulfate aerosol are well understood, many aspects of the evolution of the early volcanic aerosol cloud and regional impacts are uncertain. In the last twenty years, several advances have been made, mainly due to improved satellite measurements and observations enabling the effects of small-magnitude eruptions to be quantified, new proxy reconstructions used to investigate the impact of past eruptions, and state-of-the-art aerosol-climate modelling that has led to new insights on how volcanic eruptions affect the climate. Looking to the future, knowledge gaps include the role of co-emissions in volcanic plumes, the impact of eruptions on tropical hydroclimate and Northern Hemisphere winter climate, and the role of eruptions in long-term climate change. Future model development, dedicated model intercomparison projects, interdisciplinary collaborations, and the application of advanced statistical techniques will facilitate more complex and detailed studies. Ensuring that the next large-magnitude explosive eruption is well observed will be critical in providing invaluable observations that will bridge remaining gaps in our understanding.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1038/S41598-019-45753-4", "year": 2019, "title": "Monitoring endogenous growth of open-vent volcanoes by balancing thermal and SO2 emissions data derived from space", "abstract": "Measuring the amount of magma intruding in a volcano represents one of the main challenges of modern volcanology. While in closed-vent volcanoes this parameter is generally assessed by the inversion of deformation data, in open-vent volcanoes its measurement is more complicated and results from the balance between the magma entering and leaving the storage system. In this work we used thermal and SO2 flux data, derived from satellite measurements, to calculate the magma input and output rates of Mt. Etna between 2004 and 2010. We found that during the analysed period more magma was supplied than erupted, resulting into an endogenous growth rate equal to 22.9 13.7 106 m3 y1. Notably, this unbalance was not constant in time, but showed phases of major magma accumulation and drainage acting within a compressible magma chamber. The excellent correlation with the inflation/deflation cycles measured by ground-based GPS network suggests the thermal, SO2 flux and deformation data, can be combined to provide a quantitative analysis of magma transport inside the shallow plumbing system of Mt Etna. Given the global coverage of satellite data and the continuous improvement of sensors in orbit, we anticipate that this approach will have sufficient detail to monitor, in real time, the endogenous growth associated to other world-wide open-vent volcanoes.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/GEOSCIENCES12010040", "year": 2022, "title": "ICESat-2 Applications for Investigating Emerging Volcanoes", "abstract": "Submarine volcanism in shallow waters (<100 m), particularly in remote settings, is difficult to monitor quantitatively and, in the rare formation of islands, it is challenging to understand the rapid-paced erosion. However, these newly erupted volcanic islands become observable to airborne and/or satellite remote sensing instruments. NASAs ICESat-2 satellite laser altimeter, combined with visible imagery (optical and microwave), provide a novel method of evaluating the elevation characteristics of newly emerged volcanoes and their subaerial eruption products. Niijima Fukutoku-Okanoba (NFO) is a submarine volcano 1300 km south of Tokyo (Ogasawara Archipelago of Japan) that periodically breaches the ocean surface to create new islands that are subsequently eroded. The recent eruption in August 2021 is a rare opportunity to investigate this island evolution using high-resolution satellite datasets with geodetic-quality ICESat-2 altimetry. Lansdat-8 and Planet imagery provide a qualitative analysis of the exposed volcanic deposits, while ICESat-2 products provide elevation profiles necessary to quantify the physical surface structures. This investigation determines an innovative application for ICESat-2 data in evaluating newly emerged islands and how the combination of satellite remote sensing (visible and lidar) to investigate these short-lived volcanic features can improve our understanding of the volcanic island system in ways not previously possible.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.ATMOSENV.2020.117648", "year": 2020, "title": "Air quality impacts of the 2018 Mt. Kilauea volcano eruption in Hawaii: A regional chemical transport model study with satellite-constrained emissions", "abstract": "Volcanic eruptions emit a vast amount of sulfur dioxide (SO2) and ash into the air, often imposing substantial impacts on air quality and the ecosystem. Quantifying its impacts, however, is difficult due to the uncertainties in estimating the strength and variations of volcanic emissions. Here we developed and evaluated a new approach to combine satellite SO2 detection and chemical transport modeling to assess the impact of the 2018 Mt. Kilauea eruption on air quality over Hawaii. During the sustained eruption of the Kilauea Volcano in Hawaii's Big Island from May to July 2018, considerable SO2 and PM2.5 enhancements were observed both from the ground and from space. We studied this case using an experimental version of the NOAA National Air Quality Forecast Capability (NAQFC) modeling system. Daily emissions of SO2 and ash were estimated using a combination of SO2 column density retrieved by Ozone Mapping and Profiling Suite (OMPS) Nadir-Mapper (NM) aboard the Suomi-NPP satellite and the NAQFC model with an inverse emission modeling approach. We found that the volcanic SO2 emission rates peaked at 15,000 mol/s from the Kilauea's East Rift zone and Summit. The formation and transport of volcanic smog, or Vog, was highly dependent upon the vertical distribution of the volcanic emission, controlled by the heat flux of emission sources. We conducted four model simulations with various emission settings, and compared them to satellite data (CALIOP, OMPS and VIIRS) and in-situ measurements. All the runs tended to underpredict the peak values of surface SO2 and PM2.5 (particulate matter smaller than 2.5 m in diameter). The No Plume Rise run underestimated the Vog plume rise and downstream transport. Using fixed emission rate or removing the temporal variations (3-Day Mean) led to miss peak Vog effects or inconsistent transport pattern compared to the observations. Therefore, the Base simulation with daily-varying emission and plume rise was used to quantify the air quality effects of the Kilauea eruption. We found that the volcanic eruption elevated surface PM2.5 concentration by 3040 g/m3 in the southeast part of the Big Island, with peak values up to 300 g/m3. The Vog effect on trace gases, such as O3, NOx, and non-methane hydrocarbons, were much weaker (<1 ppbV), but extended to farther downstream.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.QUASCIREV.2020.106606", "year": 2020, "title": "New insights into source and dispersal of Mediterranean S1 tephra, an early Holocene marker horizon erupted at Mt. Erciyes (Turkey)", "abstract": "Deposition of early Holocene Eastern Mediterranean S1 tephra and a Black Sea cryptotephra coincides with cultural transitions in the Fertile Crescent termed the Neolithic Revolution as well as sapropel formation during climate variability of the African humid period, classifying them as paramount regional marker horizons for archaeology as well as paleoclimatology. Their correlations with specific eruptions of the Mt. Erciyes stratovolcanic complex (Central Anatolia) remained inconclusive though. Here, we use zircon double-dating by (UTh)/He and UTh disequilibrium methods, major and trace element tephra glass geochemistry, and probabilistic modeling of tephra dispersal in an attempt to characterize all major late Quaternary proximal tephras of Mt. Erciyes, and to correlate them with distal deposits. Furthermore, we discuss contrasting proximal and distal tephra dispersal. Three nearly-coeval rhyolitic satellite domes (Dikkartn, Perikartn, and Karagullu) erupted at Mt. Erciyes in the early Holocene, and their dome extrusions were all preceded by explosive phases producing pyroclastic material that formed tephra fall and pyroclastic flow deposits. The new eruption age of 9.03 0.55 ka (1 uncertainty here and elsewhere) for proximal Dikkartn pumice is consistent with 14C-based S1 tephra chronologies in distal locations averaging 8.92 0.03 cal ka BP. Perikartn pyroclastic flow deposits predate S1 tephra by ca. 0.8 ka according to a pair of published 14C ages, and stratigraphically overlie Karagullu fall-out, here dated to 8.2 1.8 ka. Previously undated proximal tephras of Mt. Erciyes erupted in the Late (85.2 4.9 ka) and Middle Pleistocene (154.5 5.3 ka). S1 tephra glass is chemically similar to that of Dikkartn fall-out, but also indistinguishable from that of Perikartn fall-out. Karagullu pumice is characterized by a distinct glass chemical composition, which correlates with that of unnamed cryptotephra reported for the southeastern Black Sea instead, where these results call for a re-evaluation of existing age models. Maximum lithic clast size isopleths for proximal Dikkartn fall-out indicate eastward dispersal of a 20 5 km high eruption plume by stratospheric winds, in agreement with results of probabilistic tephra dispersal modeling. This azimuth contrasts with the known distribution of S1 tephra at distal locations that are all south of Mt. Erciyes. Significant tephra occurrences at up to 1300 km distance and orthogonal to prevalent stratospheric wind directions either result from very atypical wind conditions (probability 10 %), or are caused by tephra transport by prevailing low altitude winds. Two scenarios are proposed for low altitude transport: eolian reworking of primary fall-out (more likely from the more widespread Dikkartn deposits), or co-ignimbrite ash cloud dispersal (more likely from the Perikartn eruption which predominantly produced pyroclastic flows). Because S1 tephra is chemically indistinguishable from both Dikkartn and Perikartn by major and trace element glass compositions, its exact source and dispersal mechanism remain ambiguous, although existing 14C ages for Perikartn predating those for S1 tephra favor Dikkartn as its source.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.3390/GEOSCIENCES11080309", "year": 2021, "title": "Volatile Content Implications of Increasing Explosivity of the Strombolian Eruptive Style along the Fracture Opening on the NE Villarrica Flank: Minor Eruptive Centers \u2026", "abstract": "Potential flank eruptions at the presently active Villarrica, Southern Andes Volcanic Zone (33.346 S) require the drawing of a comprehensive scenario of eruptive style dynamics, which partially depends on the degassing process. The case we consider in this study is from the Los Nevados Subgroup 2 (LNG2) and constitutes post-glacial minor eruptive centers (MECs) of basalticandesitic and basaltic composition, associated with the northeastern Villarrica flank. Petrological studies of the melt inclusions volatile content in olivine determined the pre-eruptive conditions of the shallow magma feeding system (<249 Mpa saturation pressure, 9271201 C). The volatile saturation model on pressure-dependent volatile species, measured by Fourier Transform Infrared Microspectrometry (FTIR) (H2O of 0.43.0 wt.% and CO2 of 1141586 ppm) and electron microprobe (EMP), revealed that fast cooling pyroclasts like vesicular scoria preserve a ~1.5 times larger amount of CO2, S, Cl, and volatile species contained in melt inclusions from primitive olivine (Fo7686). Evidence from geological mapping and drone surveys demonstrated the eruption chronology and spatial changes in eruption style from all the local vents along a N45 corridor. The mechanism by which LNG2 is degassed plays a critical role in increasing the explosivity uphill on the Villarrica flank from volcanic vents in the NE sector (<9 km minimum saturation depth) to the SW sector (<8.1 km), where many crystalline ballistic bombs were expulsed, rather than vesicular and spatter scoria.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.EPSL.2022.117512", "year": 2022, "title": "Reservoir depressurization driven by passive gas emissions at Ambrym volcano", "abstract": "Despite being a widespread and common process, the impact of passive volcanic degassing on the pressurization state of a magma reservoir is not well understood. If mass loss due to gas emissions results in reservoir depressurization and surface subsidence, the pressure difference between a shallow reservoir and deep magma source may result in magma recharge and eventually trigger an eruption. It is therefore important to determine how a simplified reservoir-conduit system responds to such degassing processes. Here we use an extreme example of persistent volcanic degassingAmbrymas a case study to relate sulphur dioxide mass flux with reservoir depressurization and edifice-scale subsidence, both measured from satellite-based remote sensing observations. A geodetic inversion of surface displacements measured with Interferometric Synthetic Aperture Radar modeled using the Boundary Element Method provides bounds on the reservoir pressure change during an episode of subsidence at Ambrym from 2015 to 2017. These results are input into a lumped parameter theoretical model developed by Girona et al. (2014), and the free parameters (e.g., reservoir size and conduit radius) are systematically explored. We find that the 20152017 subsidence episode is consistent with pressure decreasing at a rate of 5.2 to 2.0 MPa year1 in a reservoir at 2 km b.s.l., as a result of passive degassing. The subsidence episode is observed to end abruptly in October 2017, and no significant deformation is detected in the 14 months leading up to a rift zone intrusion and submarine eruption in December 2018, despite substantial degassing. We explain this lack of pre-eruptive deformation by an influx of 0.16 km3 of magma into a shallow (<2 km b.s.l.) reservoir that counterbalances the depressurization caused by degassing. This recharge volume is comparable with the volume of magma subsequently extracted from Ambrym's reservoir in December 2018. We conclude that at some open-vent passively degassing volcanoes, deflation caused by degassing may reduce or even cancel any inflation signal caused by magma influx. Nonetheless, detection of pre-eruptive recharge can be achieved by monitoring changes in the long-term deformation rate.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021GL095898", "year": 2021, "title": "Stratospheric temperature and ozone anomalies associated with the 2020 Australian New Year Fires", "abstract": "Stratospheric aerosol, temperature, and ozone anomalies after the 2020 Australian bushfires are documented from satellite observations. Aerosol extinction is enhanced in the Southern Hemisphere (SH) lower stratosphere (LS) in early 2020, comparable in magnitude to the Calbuco eruption in 2015. Warm temperature anomalies of 1-2 K occur in the SH LS during January-April 2020 and are coincident with enhanced aerosols. Radiative heating is indicated through anomalous temperature correlations between lower and higher latitudes. LS ozone shows midlatitude decreases several months after the aerosol maximum and before the polar vortex breakup, reaching extreme minima over the available OMPS record since 2011. Antarctic ozone depletion in the LS in 2020 reached a decadal low for both magnitude and persistence during November-December, along with record low polar temperatures and a strong polar vortex. Overall, the polar ozone depletion, temperature, and polar vortex evolution broadly resembled the effects of the Calbuco eruption in 2015.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JSAMES.2021.103262", "year": 2021, "title": "GIS-based volcanic hazards, vulnerability and risks assessment of the Guallatiri Volcano, Arica y Parinacota Region, Chile", "abstract": "This paper introduces the first GIS-based volcanic hazard, vulnerability and risk assessment of Guallatiri volcano. Volcanic hazard assessment is based on the study of five key volcanic phenomena observed during Holocene eruptions of Guallatiri volcano: i) tephra transport, dispersal and deposition; ii) flooding by lahars; iii) lava flows; iv) pyroclastic density currents; and v) ballistic projectiles. A qualitative approach is considered, assuming a relative probability of occurrence for each scenario. Hazard maps are constructed via computer modelling based on field data and some volcanic analogues and relative probability values are assigned to each scenario (the lowest magnitude/intensity scenario has the highest probability value and vice versa). After summing them up through the raster calculator tool, the result corresponds to an integrated volcanic hazard map, that shows the areas likely to be adversely affected by different volcanic processes. Vulnerability was assessed through its social, physical and territorial components considered by dividing the study area into basic administrative units (rural entities), according to the 2017 Chilean Census. Social vulnerability is evaluated through density of people, education qualification, and dependence index. Physical vulnerability is evaluated through the number of houses, and territorial vulnerability, through a critical infrastructure cadaster. A vulnerability level is assigned according to the vulnerability indicator intervals using the quantile method. In order to evaluate the overall risk, the integrated hazard map and vulnerability assessments are aggregated through the arithmetic multiplication of the layers. Consequently, three thematic risk maps are obtained: social, physical and territorial. This analysis depicts that ash transport, dispersal and fallout, indeed has the greatest impact because it is more widely distributed. If a high magnitude eruption occurred during autumn, winter or spring/summer, ash cloud movements would be to the NW, E or SE, respectively reaching Chile, Peru, Bolivia, Argentina, Brazil, and Paraguay. For volcanic processes closest to the volcanic edifice, the higher risk areas would be located towards the N, NW, and SW of the volcano affecting areas up 13 km to the localities of Chungara Viejo, Ancuta, and Guallatiri. In the case of explosive events, areas prone to be affected by tephra deposition could be blanketed with layers up to 50 cm thick, while flooding by bulky lahars could extend for up to ~19 km, and pyroclastic density currents up to ~10 km, whereas for effusive events, lava flows would extend for up to ~7 km. Consequently, the places identified here as those being at highest social risk are Nigramalla, Ancuta, and Guallatire. Due to its remoteness, this volcano and their hazards/vulnerability/risks have been underestimated so far. A future eruption will threaten these areas and the local economy mainly related to the tertiary (e.g., tourism), and primary (e.g., livestock) sectors.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021GC009911", "year": 2021, "title": "Multidisciplinary Constraints on Magma Compressibility, the Pre\u2010Eruptive Exsolved Volatile Fraction, and the H2O/CO2 Molar Ratio for the 2006 Augustine Eruption \u2026", "abstract": "Geodetically modeled reservoir volume changes during volcanic eruptions are commonly much smaller than the observed eruptive volumes. This discrepancy is thought to be partially due to the compressibility of magma, which is largely controlled by the presence of exsolved volatiles. The 2006 eruption of Augustine Volcano, Alaska, produced an eruptive volume that was \u223c3 times larger than the geodetically estimated syn-eruptive subsurface volume change. In this study, we use a multistep methodology that combines constraints from geodetic, volcanic gas, geologic, and petrologic data together with equations relating physical processes to observable parameters. We apply a Monte Carlo approach to quantify uncertainties. Ultimately, we solve for the exsolved volatile volume fraction and the magma compressibility. We estimate Augustine's 2006 pre-eruptive exsolved volatile phase to be \u223c5.5 vol% of the magma at storage depths, yielding a bulk magma compressibility of \u223c3.8 \u00d7 10-10 Pa-1. We develop a novel approach to estimate the H2O/CO2 ratio of the syn-eruptive gas emissions in the absence of direct H2O emission measurements which are hard to obtain due to the high background levels in ambient air. We find a best-fit H2O/CO2 molar ratio of 29. We also investigate the effects of applying different equations of state to our model. We find that the Ideal Gas Law might be used as a first approximation due to its simplicity; however, it overestimates volatile density and compressibility significantly at storage depths. This project capitalizes on the insights that can be gained by integrating multidisciplinary data with models of physical processes.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JAG.2018.08.027", "year": 2018, "title": "Detection of geothermal anomalies using Landsat 8 TIRS data in Tulu Moye geothermal prospect, Main Ethiopian Rift", "abstract": "Despite the high geothermal potential of the Main Ethiopian Rift (MER), risks associated with the industry and the difficulty of identifying possible targets using ground surveys alone continue to impede the development of geothermal power diligence in Ethiopia. In this paper, we investigate the geothermal potential of the Tulu Moye prospect area in the MER using Landsat 8, which is an important and cost-effective method of detecting geothermal anomalies. Data with a path/row of 168/054 were obtained from the Landsat 8 Operational Land Imager (OLI) and Thermal Infrared (TIR) sensors for October 17, 2014. Based on radiometric calibration, atmospheric correction (with the 6S model) and an NDVI-based threshold method for calculating land surface emissivity, a split-window algorithm was applied to retrieve the land surface temperature (LST) of the study area. Results show LST values ranging from 292.2 to 315.8 K, with the highest values found in barren lands. A comparison of LST between the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat 8 shows a maximum difference of 1.47 K. Anomalous areas were also discovered, where LST was about 3-9 K higher than the background area. We identified seven of these as areas of high geothermal activity in the Tulu Moye prospective geothermal area. Auxiliary data and overlay analysis tools eliminated any non-geothermal influences. The research reveals that the distribution of highy prospective geothermal areas is consistent with the development and distribution of faults in the study area. Magmatism is the thermal source and faults provide conduits for the heat to flow from earths interior to the surface, facilitating the presence of geothermal anomalies. Finally, TIR remote sensing methods prove to be a robust and cost-effective technique for detecting LST anomalies in the geologically active area of MER. Moreover, combining TIR remote sensing with knowledge of the structural geology of the area and geothermal mechanisms is an efficient approach to detecting geothermal areas.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1002/2017GL076419", "year": 2018, "title": "Diverse Eruptive Activity Revealed by Acoustic and Electromagnetic Observations of the 14 July 2013 Intense Vulcanian Eruption of Tungurahua Volcano, Ecuador", "abstract": "During the powerful July 2013 eruption of Tungurahua volcano, Ecuador, we recorded exceptionally high amplitude, long-period infrasound (1,600-Pa peak-to-peak amplitude, 5.5-s period) on sensors within 2 km of the vent alongside electromagnetic signals from volcanic lightning serendipitously captured as interference. This explosion was one of Tungurahua's most powerful vulcanian eruptions since recent activity began in 1999, and its acoustic wave is among the most powerful volcanic infrasound ever recorded anywhere. We use these data to quantify erupted volume from the main explosion and to classify postexplosive degassing into distinct emission styles. Additionally, we demonstrate a highly effective method of recording lightning-related electromagnetic signals alongside infrasound. Detailed chronologies of powerful vulcanian eruptions are rare; this study demonstrates that diverse eruptive processes can occur in such eruptions and that near-vent infrasound and electromagnetic data can elucidate them.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JSAMES.2020.103146", "year": 2021, "title": "Integrated hazards maps of the Tacan\u00e1 Volcanic complex, Mexico-Guatemala: Ashfall, block-and-ash flows, and lahars", "abstract": "The Tacana Volcanic Complex (TVC) is an active volcano, located on the border between Mexico and Guatemala, in the westernmost part of the Central American Volcanic Arc. The TVC has produced effusive and explosive activity during the past 300 ka through the emplacement of lava flows, pyroclastic deposits, debris avalanches and lahars. During the last 10 ka, at least 11 eruptions have occurred, with three small phreatic explosions documented in 18551856, 1949 and 1986. This work presents volcanic hazards maps of the TVC that integrate the results of analyzing two eruptive style scenarios: dome-collapses and Plinian-type eruptions and the lahars triggered by both these hazards. The extents and expected distributions for each of these phenomena were assessed using numerical models and the results were calibrated with recent field data. The simulation results were merged to prepare three new volcanic hazards maps, which depict on a color scale the hazard level forecasted for each phenomenon (high red, moderate orange, and low yellow). The maps show that the total extension of block-and-ash flows will be restricted towards the volcano base, reaching a maximum distance towards Guatemala of ~5 km, and ~10 km in Mexico; while lahars could reach up to 50 km downstream along the main rivers that drains the complex (i.e. Coatan, Cahoacan and Suchiate rivers) that would flood important urban centers mostly over Mexican territory. Ashfall would cover an area of ca. 8000 km2, inhabited by ~2 million people in both countries. Hence, renewed eruptive activity of the TVC would be catastrophic not only because of the loss of human life but also for its adverse impact on economic activity based on corn, coffee, and banana plantations, together with the disruption of communication and transportation systems between Mexico and Central America.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021GL096171", "year": 2022, "title": "Springtime Stratospheric Volcanic Aerosol Impact on Midlatitude Cirrus", "abstract": "Explosive volcanic eruptions can reach the stratosphere and cause elevated concentrations of sulphate particles for months to years. When these particles descend into the troposphere, they can impact cirrus clouds though to what degree is unknown. In this study, we combine three satellite data sets to investigate the impact of downwelling sulphate aerosol on midlatitude cirrus clouds during springtime. The results show that cirrus clouds in the northern hemisphere (NH) have lower ice water content (IWC), ice crystal number concentrations, and cloud fraction (CF) when the aerosol load in the lowermost stratosphere is elevated by volcanism. These changes are largest for the coldest clouds at the highest altitudes. The cirrus clouds in the southern hemisphere on the other hand show no significant changes with downwelling aerosol levels. The reduction in cirrus IWC and CF in the NH implies that volcanic aerosol can cool the climate through reduced warming from cirrus clouds.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.5194/ACP-20-345-2020", "year": 2020, "title": "Surface temperature response to the major volcanic eruptions in multiple reanalysis data sets", "abstract": "Abstract. The global response of air temperature at 2 m above the surface to the eruptions of Mount Agung in March 1963, El Chichon in April 1982, and Mount Pinatubo in June 1991 is investigated using 11 global atmospheric reanalysis data sets (JRA-55, JRA-25, MERRA-2, MERRA, ERA-Interim, ERA-40, CFSR, NCEP-NCAR R-1, 20CR version 2c, ERA-20C, and CERA-20C). Multiple linear regression (MLR) is applied to the monthly mean time series of temperature for two periods 19802010 (for 10 reanalyses) and 19582001 (for 6 reanalyses) by considering explanatory factors of seasonal harmonics, linear trends, quasi-biennial oscillation (QBO), solar cycle, tropical sea surface temperature (SST) variations in the Pacific, Indian, and Atlantic Oceans, and Arctic SST variations. Empirical orthogonal function (EOF) analysis is applied to these climatic indices to obtain a set of orthogonal indices to be used for the MLR. The residuals of the MLR are used to define the volcanic signals for the three eruptions separately. First, area-averaged time series of the residuals are investigated and compared with the results from previous studies. Then, the geographical distribution of the response during the peak cooling period after each eruption is investigated. In general, different reanalyses show similar geographical patterns of the response, but with the largest differences in the polar regions. The Pinatubo response shows the largest average cooling in the 60 N60 S region among the three eruptions, with a peak cooling of 0.100.15 K. The El Chichon response shows slightly larger cooling in the NH than in the Southern Hemisphere (SH), while the Agung response shows larger cooling in the SH. These hemispheric differences are consistent with the distribution of stratospheric aerosol optical depth after these eruptions; however, the peak cooling after these two eruptions is comparable in magnitude to unexplained cooling events in other periods without volcanic influence. Other methods in which the MLR model is used with different sets of indices are also tested, and it is found that careful treatment of tropical SST variability is necessary to evaluate the surface response to volcanic eruptions in observations and reanalyses.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1016/J.JVOLGEORES.2018.01.027", "year": 2018, "title": "Parametric analysis of lava dome-collapse events and pyroclastic deposits at Shiveluch volcano, Kamchatka, using visible and infrared satellite data", "abstract": "For the years 2001 to 2013 of the ongoing eruption of Shiveluch volcano, a combination of different satellite remote sensing data are used to investigate the dome-collapse events and the resulting pyroclastic deposits. Shiveluch volcano in Kamchatka, Russia, is one of the world's most active dome-building volcanoes, which has produced some of the largest known historical block-and-ash flows (BAFs). Globally, quantitative data for deposits resulting from such large and long-lived dome-forming eruptions, especially like those at Shiveluch, are scarce. We use Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) thermal infrared (TIR), shortwave infrared (SWIR), and visible-near infrared (VNIR) data to analyze the dome-collapse scars and BAF deposits that were formed during eruptions and collapse events in 2001, 2004, 2005, 2007, 2009, 2010, and two events in 2013. These events produced flows with runout distances of as far as 19km from the dome, and with aerial extents of as much as 22.3km2. Over the 12years of this period of investigation, there is no trend in deposit area or runout distances of the flows through time. However, two potentially predictive features are apparent in our data set: 1) the largest dome-collapse events occurred when the dome exceeded a relative height (from dome base to top) of 500m; 2) collapses were preceded by thermal anomalies in six of the cases in which ASTER data were available, although the areal extent of these precursory thermal areas did not generally match the size of the collapse events as indicated by scar area (volumes are available for three collapse events). Linking the deposit distribution to the area, location, and temperature profiles of the dome-collapse scars provides a basis for determining similar future hazards at Shiveluch and at other dome-forming volcanoes. Because of these factors, we suggest that volcanic hazard analysis and mitigation at volcanoes with similar BAF emplacement behavior may be improved with detailed, synoptic studies, especially when it is possible to access and interpret appropriate remote sensing data in near-real time.", "labels": [ { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1029/2021WR031569", "year": 2022, "title": "Wildfire Impacts on Snowpack Phenology in a Changing Climate Within the Western U.S.", "abstract": "Snowpack in the western U.S. is critical for water supply and is threatened by wildfires, which are becoming larger and more common. Numerous studies have examined impacts of wildfire on snow water equivalent (SWE), but many of these studies are limited in the number of observation locations, and they have sometimes produced conflicting results. The objective of this study is to distinguish the net effects of wildfires on snowpack from those of climate. We consider 45 burned sites from the Snow Telemetry network. For each burned site, unburned control sites are identified from the same level III ecoregion. Impacts of climate changes on snowpack are analyzed by comparing pre-fire and post-fire snow water equivalent at the unburned sites. Combined climate and wildfire effects are considered by comparing pre-fire and post-fire SWE at the burned sites. Wildfire impacts are then isolated by taking the difference between the burned and unburned sites. The wildfire-induced changes in SWE are also compared to several possible controlling variables including burn severity, leaf-area index change, dominant pre-fire tree genus, years since the fire, and site elevation. On average, wildfires have advanced melt-out dates 9 days and maximum SWE dates 6 days and reduced annual maximum SWE by 10% across the sites considered. On average, the combined effects of climate and wildfire have advanced melt-out and maximum SWE dates approximately 14 and 10 days, respectively, while decreasing annual maximum SWE by approximately 10%.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/CP-18-2211-2022", "year": 2022, "title": "Canadian forest fires, Icelandic volcanoes and increased local dust observed in six shallow Greenland firn cores", "abstract": "Abstract. Greenland ice cores provide information about past climate. Few impurity records covering the past 2 decades exist from Greenland. Here we present results from six firn cores obtained during a 426 km long northern Greenland traverse made in 2015 between the NEEM and the EGRIP deep-drilling stations situated on the western side and eastern side of the Greenland ice sheet, respectively. The cores (9 to 14 m long) are analyzed for chemical impurities and cover time spans of 18 to 53 years (3 years) depending on local snow accumulation that decreases from west to east. The high temporal resolution allows for annual layers and seasons to be resolved. Insoluble dust, ammonium, and calcium concentrations in the six firn cores overlap, and the seasonal cycles are also similar in timing and magnitude across sites, while peroxide (H2O2) and conductivity both have spatial variations, H2O2 driven by the accumulation pattern, and conductivity likely influenced by sea salt. Overall, we determine a rather constant dust flux over the period, but in the data from recent years (19982015) we identify an increase in large dust particles that we ascribe to an activation of local Greenland sources. We observe an expected increase in acidity and conductivity in the mid-1970s as a result of anthropogenic emissions, followed by a decrease due to mitigation. Several volcanic horizons identified in the conductivity and acidity records can be associated with eruptions in Iceland and in the Barents Sea region. From a composite ammonium record we obtain a robust forest fire proxy associated primarily with Canadian forest fires (R=0.49).", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 18, "name": "Volcanic Eruptions" } ] }, { "doi": "10.1088/1748-9326/AC7342", "year": 2022, "title": "A compound event-oriented framework to tropical fire risk assessment in a changing climate", "abstract": "Abstract\r\n Tropical fire activity closely follows the co-occurrence of multiple climate stressors. Yet, it remains challenging to quantify how changes in climate alter the likelihood of fire risks associated with compound events. Recent abrupt changes in fire regimes in iconic landscapes in Brazil (namely the Pantanal and Xingu) provide a key opportunity to evaluate how extremely dry and hot conditions, both together and individually, have influenced the probability of large fires. Here we quantify the relationships between climate and fire across these regions and provide evidence on the extent to which fire risk and the associated impacts could be constrained if anthropogenic global warming is limited. We investigate the burned area, differentiating between fire types according to land use (forest fires, savanna fires, farming fires and grassland and wetland fires), and derive present and future fire risks linked to multiple climate variables. We show that concurrent air dryness (high vapour-pressure deficit (VPD)) and low precipitation have driven fire occurrence in both Xingu and the Pantanal, with VPD playing a dominant role. Historical climatic change has already increased compound event-related (CE-related) fire risks of all fire types (5%10%), and these risks are likely to increase in the future due to global warming. The likelihood of CE-related increase in fire risk may be reduced by up to 14.4% if global warming is constrained to +1.5 C instead of +3 C. Nevertheless, substantially increased CE-related fire risks are still expected even if restricting global mean warming to 1.5 C, particularly in the Pantanal. We thus conclude that climate action should be coordinated with environmental protection to reduce ignition sources and promote effective conservation measures to preserve these biomes.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1111/GEB.13034", "year": 2020, "title": "Thresholds of fire response to moisture and fuel load differ between tropical savannas and grasslands across continents", "abstract": "AimAn emerging framework for tropical ecosystems states that fire activity is either \"fuel build\u2011up limited\" or \"fuel moisture limited\", that is, as you move up along rainfall gradients, the major control on fire occurrence switches from being the amount of fuel, to the moisture content of the fuel. Here we used remotely sensed datasets to assess whether interannual variability of burned area is better explained by annual rainfall totals driving fuel build\u2011up, or by dry season rainfall driving fuel moisture.LocationPantropical savannas and grasslands.Time period2002\u20132016.MethodsWe explored the response of annual burned area to interannual variability in rainfall. We compared several linear models to understand how fuel moisture and fuel build\u2011up effect (accumulated rainfall during 6 and 24 months prior to the end of the burning season, respectively) determine the interannual variability of burned area and explore if tree cover, dry season duration and human activity modified these relationships.ResultsFuel and moisture controls on fire occurrence in tropical savannas varied across continents. Only 24% of South American savannas were fuel build\u2011up limited against 61% of Australian savannas and 47% of African savannas. On average, South America switched from fuel limited to moisture limited at 500 mm/year, Africa at 800 mm/year and Australia at 1,000 mm/year of mean annual rainfall.Main conclusionsIn 42% of tropical savannas (accounting for 41% of current area burned) increased drought and higher temperatures will not increase fire, but there are savannas, particularly in South America, that are likely to become more flammable with increasing temperatures. These findings highlight that we cannot transfer knowledge of fire responses to global change across ecosystems/regions\u2014local solutions to local fire management issues are required, and different tropical savanna regions may show contrasting responses to the same drivers of global change.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-20-11065-2020", "year": 2020, "title": "Quantifying the effects of environmental factors on wildfire burned area", "abstract": "Abstract. Occurrences of devastating wildfires have been increasing\nin the United States for the past decades. While some environmental\ncontrols, including weather, climate, and fuels, are known to play important\nroles in controlling wildfires, the interrelationships between these factors\nand wildfires are highly complex and may not be well represented by\ntraditional parametric regressions. Here we develop a model consisting of\nmultiple machine learning algorithms to predict 0.50.5 gridded\nmonthly wildfire burned area over the south central United States during\n20022015 and then use this model to identify the relative importance of the\nenvironmental drivers on the burned area for both the winterspring and\nsummer fire seasons of that region. The developed model alleviates the issue\nof unevenly distributed burned-area data, predicts burned grids with area\nunder the curve (AUC) of 0.82 and 0.83 for the two seasons, and achieves\ntemporal correlations larger than 0.5 for more than 70 % of the grids and\nspatial correlations larger than 0.5 (p<0.01) for more than 60 %\nof the months. For the total burned area over the study domain, the model\ncan explain 50 % and 79 % of the observed interannual variability for\nthe winterspring and summer fire season, respectively. Variable importance\nmeasures indicate that relative humidity (RH) anomalies and preceding\nmonths' drought severity are the two most important predictor variables\ncontrolling the spatial and temporal variation in gridded burned area for\nboth fire seasons. The model represents the effect of climate variability by\nclimate-anomaly variables, and these variables are found to contribute the\nmost to the magnitude of the total burned area across the whole domain for\nboth fire seasons. In addition, antecedent fuel amounts and conditions are\nfound to outweigh the weather effects on the amount of total burned area in\nthe winterspring fire season, while fire weather is more important for the\nsummer fire season likely due to relatively sufficient vegetation in this\nseason.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1007/978-3-030-87045-4_3", "year": 2022, "title": "Fire Behavior and Heat Release as Source Conditions for Smoke Modeling", "abstract": "Abstract\r\n Modeling smoke dispersion from wildland fires is a complex problem. Heat and emissions are released from a fire front as well as from post-frontal combustion, and both are continuously evolving in space and time, providing an emission source that is unlike the industrial sources for which most dispersion models were originally designed. Convective motions driven by the fires heat release strongly couple the fire to the atmosphere, influencing the development and dynamics of the smoke plume. This chapter examines how fire events are described in the smoke modeling process and explores new research tools that may offer potential improvements to these descriptions and can reduce uncertainty in smoke model inputs. Remote sensing will help transition these research tools to operations by providing a safe and reliable means of measuring the fire environment at the space and time scales relevant to fire behavior.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.5194/AGILE-GISS-1-6-2020", "year": 2020, "title": "Integrating cellular automata and discrete global grid systems: a case study into wildfire modelling", "abstract": "Abstract. With new forms of digital spatial data driving new applications for monitoring and understanding environmental change, there are growing demands on traditional GIS tools for spatial data storage, management and processing. Discrete Global Grid System (DGGS) are methods to tessellate globe into multiresolution grids, which represent a global spatial fabric capable of storing heterogeneous spatial data, and improved performance in data access, retrieval, and analysis. While DGGS-based GIS may hold potential for next-generation big data GIS platforms, few of studies have tried to implement them as a framework for operational spatial analysis. Cellular Automata (CA) is a classic dynamic modeling framework which has been used with traditional raster data model for various environmental modeling such as wildfire modeling, urban expansion modeling and so on. The main objectives of this paper are to (i) investigate the possibility of using DGGS for running dynamic spatial analysis, (ii) evaluate CA as a generic data model for dynamic phenomena modeling within a DGGS data model and (iii) evaluate an in-database approach for CA modelling. To do so, a case study into wildfire spread modelling is developed. Results demonstrate that using a DGGS data model not only provides the ability to integrate different data sources, but also provides a framework to do spatial analysis without using geometry-based analysis. This results in a simplified architecture and common spatial fabric to support development of a wide array of spatial algorithms. While considerable work remains to be done, CA modelling within a DGGS-based GIS is a robust and flexible modelling framework for big-data GIS analysis in an environmental monitoring context. ", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/RS12132162", "year": 2020, "title": "An Adaptive and Extensible System for Satellite-Based, Large Scale Burnt Area Monitoring in Near-Real Time", "abstract": "In the case of ongoing wildfire events, timely information on current fire parameters is crucial for informed decision making. Satellite imagery can provide valuable information in this regard, since thermal sensors can detect the exact location and intensity of an active fire at the moment the satellite passes over. This information can be derived and distributed in near-real time, allowing for a picture of current fire activity. However, the derivation of the size and shape of an already affected area is more complex and therefore most often not available within a short time frame. For urgent decision making though, it would be desirable to have this information available in near-real time, and on a large scale. The approach presented here works fully automatic and provides perimeters of burnt areas within two hours after the satellite scene acquisition. It uses the red and near-infrared bands of mid-resolution imagery to facilitate continental-scale monitoring of recently occurred burnt areas. To allow for a high detection capacity independent of the affected vegetation type, segmentation thresholds are derived dynamically from contextual information. This is done by using a Morphological Active Contour approach for perimeter determination. The results are validated against semi-automatically derived burnt areas for five wildfire incidents in Europe. Furthermore, these results are compared with three widely used burnt area datasets on a country-wide scale. It is shown that a high detection quality can be reached in near real-time. The large-scale inter-comparison shows that the results coincide with 63% to 76% of the burnt area in the reference datasets. While these established datasets are only available with a time lag of several months or are created by using manual interaction, the presented approach produces results in near-real time fully automatically. This work is therefore supposed to represent a valuable improvement in wildfire related rapid damage assessment.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1002/EAP.2588", "year": 2022, "title": "Wild, Tamed, and Domesticated: Three fire macroregimes for global pyrogeography in the Anthropocene", "abstract": "Climate and natural vegetation dynamics are key drivers of global vegetation fire, but anthropogenic burning now prevails over vast areas of the planet. Fire regime classification and mapping may contribute towards improved understanding of relationships between those fire drivers. We used 15 years of daily active fire data from the MODIS fire product (MCD14ML, collection 6) to create global maps of six fire descriptors (incidence, size inequality, season length, interannual variability, intensity, and fire season modality). Using multiple correspondence analysis (MCA) and hierarchical agglomerative clustering, we identified three fire macroregimes: Wild, Tamed, and Domesticated, each of which splitting into prototypical and transitional regimes. Interpretation of the six fire regimes in terms of their main drivers relied on the global maps of anthromes and K\u00f6ppen climate types. The analysis yielded a two\u2011dimensional space where the principal dimension of variability is primarily defined by interannual variability in fire activity and fire season length, and the secondary axis is based mainly on fire incidence. The Wild fire macroregime occurs mostly in cold wildlands, where burning is sporadic and fire seasons are short. Tamed fires predominate in seasonally dry tropical rangelands and croplands with high fire incidence. Domesticated fires are characteristic of humid, warm temperate and tropical croplands and villages with low fire incidence. The Tamed and Domesticated fire macroregimes, representing managed burning, account for 86% of all active fires in our dataset and for 70% of the global burnable area. Fourteen percent of active fires were found in the cold wildlands, and in the rangelands and forests of steppe and desert climates of the Wild macroregime. These results highlight the extent of human control over global pyrogeography in the Anthropocene.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1088/1748-9326/AB8847", "year": 2020, "title": "Patterns of population displacement during mega-fires in California", "abstract": "Abstract\r\n The Facebook Disaster Maps (FBDM) work presented here is the first time this platform has been used to provide analysis-ready population change products derived from crowdsourced data targeting disaster relief practices. We evaluate the representativeness of FBDM data using the Mann-Kendall test and emerging hot and cold spots in an anomaly analysis to reveal the trend, magnitude, and agglommeration of population displacement during the Mendocino Complex and Woolsey fires in California, USA. Our results show that the distribution of FBDM pre-crisis users fits well with the total population from different sources. Due to usage habits, the elder population is underrepresented in FBDM data. During the two mega-fires in California, FBDM data effectively captured the temporal change of population arising from the placing and lifting of evacuation orders. Coupled with monotonic trends, the fall and rise of cold and hot spots of population revealed the areas with the greatest population drop and potential places to house the displaced residents. A comparison between the Mendocino Complex and Woolsey fires indicates that a densely populated region can be evacuated faster than a scarcely populated one, possibly due to better access to transportation. In sparsely populated fire-prone areas, resources should be prioritized to move people to shelters as the displaced residents do not have many alternative options, while their counterparts in densely populated areas can utilize their social connections to seek temporary stay at nearby locations during an evacuation. Integrated with an assessment on underrepresented communities, FBDM data and the derivatives can provide much needed information of near real-time population displacement for crisis response and disaster relief. As applications and data generation mature, FBDM will harness crowdsourced data and aid first responder decision-making.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/TC-14-3731-2020", "year": 2020, "title": "Tracing devastating fires in Portugal to a snow archive in the Swiss", "abstract": "Abstract. Recent large wildfires, such as those in Portugal in\n2017, have devastating impacts on societies, economy, ecosystems and\nenvironments. However, wildfires are a natural phenomenon, which has been\nexacerbated by land use during the past millennia. Ice cores are one of the\narchives preserving information on fire occurrences over these timescales. A\ndifficulty is that emission sensitivity of ice cores is often unknown, which\nconstitutes a source of uncertainty in the interpretation of such archives.\nInformation from specific and well-documented case studies is therefore\nuseful to better understand the spatial representation of ice-core burning\nrecords. The wildfires near Pedrogao Grande in central Portugal in\n2017 provided a test bed to link a fire event to its footprint left in a\nhigh-alpine snowpack considered a surrogate for high-alpine ice-core sites.\nHere, we (1) analysed black carbon (BC) and microscopic charcoal particles\ndeposited in the snowpack close to the high-alpine research station\nJungfraujoch in the Swiss Alps; (2) calculated backward trajectories based\non ERA-Interim reanalysis data and simulated the transport of these\ncarbonaceous particles using a global aerosol-climate model; and (3)\nanalysed the fire spread, its spatial and temporal extent, and its\nintensity with remote-sensing (e.g. MODIS) Active Fire and Burned Area products. According to modelled emissions of the FINN v1.6 database, the\nfire emitted a total amount of 203.5 t BC from a total burned area of 501 km2 as observed on the basis of satellite fire products. Backward\ntrajectories unambiguously linked a peak of atmospheric-equivalent BC\nobserved at the Jungfraujoch research station on 22 June with\nelevated levels until 25 June with the highly intensive fires in\nPortugal. The atmospheric signal is in correspondence with an outstanding\npeak in microscopic charcoal observed in the snow layer, depositing nearly\nas many charcoal particles as during an average year in other ice archives.\nIn contrast to charcoal, the amount of atmospheric BC deposited during the\nfire episode was minor due to a lack of precipitation. Simulations with a\nglobal aerosol-climate model suggest that the observed microscopic\ncharcoal particles originated from the fires in Portugal and that their\ncontribution to the BC signal in snow was negligible. Our study revealed\nthat microscopic charcoal can be transported over long distances (1500 km)\nand that snow and ice archives are much more sensitive to distant events\nthan sedimentary archives, for which the signal is dominated by local fires.\nThe findings are important for future ice-core studies as they document\nthat, for BC as a fire tracer, the signal preservation depends on precipitation.\nSingle events, like this example, might not be preserved due to unfavourable\nmeteorological conditions.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/AMT-13-1427-2020", "year": 2020, "title": "The 2018 fire season in North America as seen by TROPOMI: aerosol layer height intercomparisons and evaluation of model-derived plume heights", "abstract": "Abstract. Before the launch of the TROPOspheric Monitoring Instrument (TROPOMI), only two other satellite instruments were able to observe aerosol plume heights globally, the Multi-angle Imaging SpectroRadiometer (MISR) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). The TROPOMI aerosol layer height is a potential game changer, since it has daily global coverage, and the aerosol layer height retrieval is available in near real time. The aerosol layer height can be useful for aviation and air quality alerts, as well as for improving air quality forecasting related to wildfires. Here, TROPOMI's aerosol layer height product is evaluated with MISR and CALIOP observations for wildfire plumes in North America for the 2018 fire season (June to August). Further, observing system simulation experiments were performed to interpret the fundamental differences between the different products. The results show that MISR and TROPOMI are, in theory, very close for aerosol profiles with single plumes. For more complex profiles with multiple plumes, however, different plume heights are retrieved; the MISR plume height represents the top layer, and the plume height retrieved with TROPOMI tends to have an average altitude of several plume layers. The comparison between TROPOMI and MISR plume heights shows that, on average, the TROPOMI aerosol layer heights are lower, by approximately 600 m, compared to MISR, which is likely due to the different measurement techniques. From the comparison to CALIOP, our results show that the TROPOMI aerosol layer height is more accurate over dark surfaces, for thicker plumes, and plumes between approximately 1 and 4.5 km. MISR and TROPOMI are further used to evaluate the plume height of Environment and Climate Change Canada's operational forecasting system FireWork with fire plume injection height estimates from the Canadian Forest Fire Emissions Prediction System (CFFEPS). The modelled plume heights are similar compared to the satellite observations but tend to be slightly higher with average differences of 270580 and 60320 m compared to TROPOMI and MISR, respectively.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.3390/RS13152853", "year": 2021, "title": "Relationship between Fire Events and Land Use Changes in the State of S\u00e3o Paulo, Brazil", "abstract": "This study investigated the land use and land cover changes in the state of Sao Paulo, Brazil, for the period of 2002 through 2017, to determine if forested areas were burned or converted to other land uses, to analyze the use of fire as a catalyst and mechanism for land cover change, and to determine if there was a relationship between land use changes and gross domestic product (GDP). MapBiomas classifications and MODIS data were analyzed using the Google Earth Engine. The results of the analysis found that there were minimal changes in the forested areas in Sao Paulo during the study period; however, there was a 5% increase in natural forest and a 75% increase in planted forest cover. On the other hand, there was a 128% increase in sugarcane, and nearly a 50% decrease in pasture land coverage, suggesting that land was converted from pasture to more profitable agricultural land. Finally, there was a strong positive correlation (r = 0.96) between the increase in sugarcane and the GDP, and a negative correlation between the frequency of fire events and economic production (r = 0.62). Overall, there was a decline in fire events in Sao Paulo, with fire events occurring in less than 2% of the total observed land area by 2017. This overall declining trend in fire events are likely the direct result of increases in green harvest methods, which prevent the need for pre-harvest burning.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1002/2016JD025040", "year": 2016, "title": "Agricultural fires in the southeastern US during SEAC\u2074RS: Emissions of trace gases and particles and evolution of ozone, reactive nitrogen, and organic aerosol", "abstract": "Emissions from 15 agricultural fires in the southeastern U.S. were measured from the NASA DC8 research aircraft during the summer 2013 Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign. This study reports a detailed set of emission factors (EFs) for 25 trace gases and 6 fine particle species. The chemical evolution of the primary emissions in seven plumes was examined in detail for ~1.2 h. A Lagrangian plume crosssection model was used to simulate the evolution of ozone (O3), reactive nitrogen species, and organic aerosol (OA). Observed EFs are generally consistent with previous measurements of crop residue burning, but the fires studied here emitted high amounts of SO2 and fine particles, especially primary OA and chloride. Filterbased measurements of aerosol light absorption implied that brown carbon (BrC) was ubiquitous in the plumes. In aged plumes, rapid production of O3, peroxyacetyl nitrate (PAN), and nitrate was observed with O3/CO, PAN/NOy, and nitrate/NOy reaching ~0.1, ~0.3, and ~0.3. For five selected cases, the model reasonably simulated O3 formation but underestimated PAN formation. No significant evolution of OA mass or BrC absorption was observed. However, a consistent increase in oxygentocarbon (O/C) ratios of OA indicated that OA oxidation in the agricultural fire plumes was much faster than in urban and forest fire plumes. Finally, total annual SO2, NOx , and CO emissions from agricultural fires in Arkansas, Louisiana, Mississippi, and Missouri were estimated (within a factor of ~2) to be equivalent to ~2% SO2 from coal combustion and ~1% NOx and ~9% CO from mobile sources.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1016/J.CLAY.2020.105675", "year": 2020, "title": "Post-wildfire denudation assessed from compositional features of river sediments (Central Portugal)", "abstract": "The wildfires of 2017 were responsible for vegetation clearance in a wide area of central Portugal, leaving the weathering profiles more exposed to erosive action. In the present research, suspended loads from a set of catchment areas affected by these fires with diverse geological and orographic features were periodically sampled to evaluate spatial and seasonal variability in sediment production. Bulk mineralogy reflected the geology of the source areas, but displayed high variability even for a single sampling site, which can be partially linked to the grain-size control on sediment composition. Clay mineralogy provided a better picture of the denudation at catchment scale. The predominance of detrital illite with low I5/I10 (ratio of the intensities at 5 A (002) and 10 A (001)) indicated very shallow weathering profiles. Chlorite was usually the second most common mineral, more common in metasedimentary-derived sediments, whilst kaolinite was detected only in less steep catchment areas with a predominance of granitic basement rocks or where previous-cycle depositional units are also present. Year-long shifts in clay assemblages were attributed to different spatial patterns of denudation. A depletion of kaolinite occurred in sampling sites mainly sourced by granitoids. An opposite trend was observed where areas with Meso-Cenozoic deposits, less affected by the wildfires than those with basement units, occupy significant proportions of the drainage basins. This trend was ascribed to the wearing out of the weathering profiles covering the basement. Regolith denudation was also testified by a progressive decrease in I5/I10. Shifts in clay mineralogy linked with progressive surface denudation were found to be limited in areas with shallow soils, but may complicate any paleoenvironmental reconstructions based on sediment composition when more evolved weathering profiles have been eroded.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/NHESS-21-73-2021", "year": 2021, "title": "Assessing the accuracy of remotely sensed fire datasets across the southwestern Mediterranean Basin", "abstract": "Abstract. Recently, many remote-sensing datasets providing features of individual fire events from gridded global burned area products have been released. Although very promising, these datasets still lack a quantitative estimate of their accuracy with respect to historical ground-based fire datasets. Here, we compared three state-of-the-art remote-sensing datasets (RSDs; Fire Atlas, FRY, and GlobFire) with a harmonized ground-based dataset (GBD) compiled by fire agencies monitoring systems across the southwestern Mediterranean Basin (20052015). We assessed the agreement between the RSDs and the GBD with respect to both burned area (BA) and number of fires (NF). RSDs and the GBD were aggregated at monthly and 0.25 resolutions, considering different individual fire size thresholds ranging from 1 to 500 ha. Our results show that all datasets were highly correlated in terms of monthly BA and NF, but RSDs severely underestimated both (by 38 % and 96 %, respectively) when considering all fires > 1 ha. The agreement between RSDs and the GBD was strongly dependent on individual fire size and strengthened when increasing the fire size threshold, with fires > 100 ha denoting a higher correlation and much lower error (BA 10 %; NF 35 %). The agreement was also higher during the warm season (May to October) in particular across the regions with greater fire activity such as the northern Iberian Peninsula. The Fire Atlas displayed a slightly better performance with a lower relative error, although uncertainty in the gridded BA product largely outpaced uncertainties across the RSDs. Overall, our findings suggest a reasonable agreement between RSDs and the GBD for fires larger than 100 ha, but care is needed when examining smaller fires at regional scales.", "labels": [ { "id": 20, "name": "Wildfires" } ] }, { "doi": "10.1038/S41467-018-04687-7", "year": 2018, "title": "Emissions mitigation opportunities for savanna countries from early dry season fire management", "abstract": "Savanna fires produce significant emissions globally, but if managed effectively could provide an important mitigation opportunity, particularly in African least developed countries. Here we show global opportunities for emissions reductions through early dry season burning for 37 countries including: 29 countries in Africa (69.1 MtCO2-e yr1), six countries in South America (13.3 MtCO2-e yr1), and Australia and Papua New Guinea (6.9 MtCO2-e yr1). Emissions reduction estimates are based on the successful approach developed in Australia to reduce emissions from savanna fires using global-scale, remotely sensed estimates of monthly emissions. Importantly, 20 least developed countries in Africa account for 74% of the mitigation potential (60.2 MtCO2-e yr1). More than 1.02 million km2 of savanna dominated protected areas within these countries could be used as pilot sites to test and advance a regional approach to mitigation efforts for savanna fires in Africa. Potential versus actual abatement opportunities are discussed.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3389/FFGC.2020.00087", "year": 2020, "title": "Patterns of ecosystem structure and wildfire carbon combustion across six ecoregions of the North American boreal forest", "abstract": "Increases in fire frequency, extent, and severity are expected to strongly impact the structure and function of boreal forest ecosystems. An important function of the boreal forest is its ability to sequester and store carbon (C). Increasing disturbance from wildfires, emitting large amounts of C to the atmosphere, may create a positive feedback to climate warming. Variation in ecosystem structure and function throughout the boreal forest is important for predicting the effects of climate warming and changing fire regimes on C dynamics. In this study, we compiled data on soil characteristics, stand structure, pre-fire C pools, C loss from fire, and the potential drivers of these C metrics from 527 sites distributed across six ecoregions of North Americas western boreal forests. We assessed structural and functional differences between these fire-prone ecoregions using data from 417 recently burned sites (20042015) and estimated ecoregion-specific relationships between soil characteristics and depth from 167 of these sites plus an additional 110 sites (27 burned, 83 unburned). We found that northern boreal ecoregions were generally older, stored and emitted proportionally more belowground than aboveground C, and exhibited lower rates of C accumulation over time than southern ecoregions. We present ecoregion-specific estimates of depth-wise soil characteristics that are important for predicting C combustion from fire. As climate continues to warm and disturbance from wildfires increases, the C dynamics of these fire-prone ecoregions are likely to change with significant implications for the global C cycle and its feedbacks to climate change.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-22-4129-2022", "year": 2022, "title": "Radiative and microphysical responses of clouds to an anomalous increase in fire particles over the Maritime Continent in 2015", "abstract": "Abstract. The year of 2015 was an extremely dry year for Southeast Asia where the direct impact of a strong El Nino was in play. As a result of this dryness and the relative lack of rainfall, an extraordinary quantity of aerosol particles from biomass burning remained in the atmosphere over the Maritime Continent during the fire season. This study uses the Weather Research and Forecasting model coupled with Chemistry to understand the impacts of these fire particles on cloud microphysics and radiation during the peak biomass burning season in September. Our simulations, one with fire particles and the other without them, cover the entire Maritime Continent region at a cloud-resolving resolution (4 km) for the entire month of September in 2015. The comparison of the simulations shows a clear sign of precipitation enhancement by fire particles through microphysical effects; smaller cloud droplets remain longer in the atmosphere to later form ice crystals, and/or they are more easily collected by ice-phase hydrometeors in comparison to droplets under no fire influences. As a result, the mass of ice-phase hydrometeors increases in the simulation with fire particles, and so does rainfall. On the other hand, the aerosol radiative effect weakly counteracts the invigoration of convection. Clouds are more reflective in the simulation with fire particles as ice mass increases. Combined with the direct scattering of sunlight by aerosols, the simulation with fire particles shows higher albedo over the simulation domain on average. The simulated response of clouds to fire particles in our simulations clearly differs from what was presented by two previous studies that modeled aerosolcloud interaction in years with different phases of El NinoSouthern Oscillation (ENSO), suggesting a further need for an investigation on the possible modulation of fireaerosolconvection interaction by ENSO.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/S41558-020-00920-8", "year": 2020, "title": "Fuel availability not fire weather controls boreal wildfire severity and carbon emissions", "abstract": "Carbon (C) emissions from wildfires are a key terrestrialatmosphere interaction that influences global atmospheric composition and climate. Positive feedbacks between climate warming and boreal wildfires are predicted based on top-down controls of fire weather and climate, but C emissions from boreal fires may also depend on bottom-up controls of fuel availability related to edaphic controls and overstory tree composition. Here we synthesized data from 417 field sites spanning six ecoregions in the northwestern North American boreal forest and assessed the network of interactions among potential bottom-up and top-down drivers of C emissions. Our results indicate that C emissions are more strongly driven by fuel availability than by fire weather, highlighting the importance of fine-scale drainage conditions, overstory tree species composition and fuel accumulation rates for predicting total C emissions. By implication, climate change-induced modification of fuels needs to be considered for accurately predicting future C emissions from boreal wildfires.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/APP12062805", "year": 2022, "title": "Ranking of Basin-Scale Factors Affecting Metal Concentrations in River Sediment", "abstract": "River sediments often contain potentially harmful pollutants such as metals. Much research has been conducted to identify factors involved in sediment concentrations of metals. While most metal pollution studies focus on smaller scales, it has been shown that basin-scale parameters are powerful predictors of river water quality. The present study focused on basin-scale factors of metal concentrations in river sediments. The study was performed on the contiguous USA using Random Forest (R.F.) to analyze the importance of different factors of the metal pollution potential of river sediments and evaluate the possibility of assessing this potential from basin characteristics. Results indicated that the most important factors belonged to the groups Geology, Dams, and Land cover. Rock characteristics (contents of K2O, CaO, and SiO2) and reservoir drainage area were strong factors. Vegetation indices were more important than land cover types. The response of different metals to basin-scale factors varied greatly. The R.F. models performed well with prediction errors of 16.5% to 28.1%, showing that basin-scale parameters hold sufficient information for predicting potential metal concentrations. The results contribute to research and policymaking dependent on understanding large-scale factors of metal pollution.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1371/JOURNAL.PONE.0245991", "year": 2021, "title": "Mega-dams and extreme rainfall: Disentangling the drivers of extensive", "abstract": "Extreme weather events and the presence of mega-hydroelectric dams, when combined, present an emerging threat to natural habitats in the Amazon region. To understand the magnitude of these impacts, we used remote sensing data to assess forest loss in areas affected by the extreme 2014 flood in the entire Madeira River basin, the location of two mega-dams. In addition, forest plots (26 ha) were monitored between 2011 and 2015 (14,328 trees) in order to evaluate changes in tree mortality, aboveground biomass (AGB), species composition and community structure around the Jirau reservoir (distance between plots varies from 1 to 80 km). We showed that the mega-dams were the main driver of tree mortality in Madeira basin forests after the 2014 extreme flood. Forest loss in the areas surrounding the reservoirs was 56 km\r\n 2\r\n in Santo Antonio, 190 km\r\n 2\r\n in Jirau (7.49.2% of the forest cover before flooding), and 79.9% above that predicted in environmental impact assessments. We also show that climatic anomalies, albeit with much smaller impact than that created by the mega-dams, resulted in forest loss along different Madeira sub-basins not affected by dams (34173 km\r\n 2\r\n ; 0.51.7%). The impact of flooding was greater in\r\n varzea\r\n and transitional forests, resulting in high rates of tree mortality (88100%), AGB decrease (89100%), and reduction of species richness (78100%). Conversely,\r\n campinarana\r\n forests were more flood-tolerant with a slight decrease in species richness (6%) and similar AGB after flooding. Taking together satellite and field measurements, we estimate that the 2014 flood event in the Madeira basin resulted in 8.8112.47 10\r\n 6\r\n tons of dead biomass. Environmental impact studies required for environmental licensing of mega-dams by governmental agencies should consider the increasing trend of climatic anomalies and the high vulnerability of different habitats to minimize the serious impacts of dams on Amazonian biodiversity and carbon stocks.", "labels": [ { "id": 9, "name": "Floods" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.2166/NH.2022.013", "year": 2022, "title": "Green infrastructure and climate change impacts on the flows and water quality of urban catchments: Salmons Brook and Pymmes Brook in north-east London", "abstract": "Poor water quality is a widespread issue in urban rivers and streams in London. Localised pollution can have impacts on local communities, from health issues to environmental degradation and restricted recreational use of water. The Salmons and Pymmes Brooks, located in the London Borough of Enfield, flow into the River Lee, and in this paper, the impacts of misconnected sewers, urban runoff and atmospheric pollution have been evaluated. The first step towards finding a sustainable and effective solution to these issues is to identify sources and paths of pollutants and to understand their cycle through catchments and rivers. The INCA water quality model has been applied to the Salmons and Pymmes urban catchments in north-east London, with the aim of providing local communities and community action groups such as Thames21 with a tool they can use to assess the water quality issue. INCA is a process-based, dynamic flow and quality model, and so it can account for daily changes in temperature, flow, water velocity and residence time that all affect reaction kinetics and hence chemical flux. As INCA is process-based, a set of mitigation strategies have been evaluated including constructed wetland across the catchment to assess pollution control. The constructed wetlands can make a significant difference reducing sediment transport and improving nutrient control for nitrogen and phosphorus. The results of this paper show that a substantial reduction in nitrate, ammonium and phosphorus concentrations can be achieved if a proper catchment-scale wetland implementation strategy is put in place. Furthermore, the paper shows how the nutrient reduction efficiency of the wetlands should not be affected by climate change.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1175/JTECH-D-18-0018.1", "year": 2018, "title": "A multivariate empirical orthogonal function method to construct nitrate maps in the Southern Ocean", "abstract": "Abstract The ability to construct nitrate maps in the Southern Ocean (SO) from sparse observations is important for marine biogeochemistry research, as it offers a geographical estimate of biological productivity. The goal of this study is to infer the skill of constructed SO nitrate maps using varying data sampling strategies. The mapping method uses multivariate empirical orthogonal functions (MEOFs) constructed from nitrate, salinity, and potential temperature (N-S-T) fields from a biogeochemical general circulation model simulation Synthetic N-S-T datasets are created by sampling modeled N-S-T fields in specific regions, determined either by random selection or by selecting regions over a certain threshold of nitrate temporal variances. The first 500 MEOF modes, determined by their capability to reconstruct the original N-S-T fields, are projected onto these synthetic N-S-T data to construct time-varying nitrate maps. Normalized root-mean-square errors (NRMSEs) are calculated between the constructed nitrate maps and the original modeled fields for different sampling strategies. The sampling strategy according to nitrate variances is shown to yield maps with lower NRMSEs than mapping adopting random sampling. A k-means cluster method that considers the N-S-T combined variances to identify key regions to insert data is most effective in reducing the mapping errors. These findings are further quantified by a series of mapping error analyses that also address the significance of data sampling density. The results provide a sampling framework to prioritize the deployment of biogeochemical Argo floats for constructing nitrate maps.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.RSE.2012.10.019", "year": 2013, "title": "Remote sensing of suspended sediment concentration and hydrologic connectivity in a complex wetland environment", "abstract": "Maintaining the ecological diversity and hydrologic connectivity of freshwater delta systems depends on regular recharge of floodplains with river water, which can be difficult to observe on the ground. Rivers that form deltas often carry large amounts of suspended sediment, but floodplain lakes and wetlands usually have little sediment in suspension. Remote observation of high sediment water in lakes and wetlands therefore often indicates connectivity with the river network. In this study, we use daily 250-m MODIS imagery in band 1 (620670nm) and band 2 (841876nm) to monitor suspended sediment transport and, by proxy, hydrologic recharge in the PeaceAthabasca Delta, Canada. To identify an appropriate suspended sediment concentration (SSC)-reflectance model, we compare 31 published empirical equations using a field dataset containing 147 observations of SSC and in situ spectral reflectance. Results suggest potential for spatial transferability of such models, but success is contingent on the equation meeting certain criteria: 1) use of a near infrared band in combination with at least one visible band, 2) development based on SSCs similar to those in the observed region, and 3) a nonlinear form. Using a highly predictive SSC-reflectance model (Spearman's =0.95), we develop a twelve-year time series of SSC in the westernmost end of Lake Athabasca, observe the timing and sources of major sediment flux events, and identify a threshold river discharge of ~1700m3/s above which SSC in Lake Athabasca is clearly associated with flow in the Athabasca River. We also track the influx of Athabasca River water to floodplain lakes, and in three of the lakes identify distinct discharge thresholds (1040m3/s, 1150m3/s, and 1850m3/s) which result in lake recharge. For each of these lakes, we find a statistically significant decline in the threshold exceedence frequency since 1970, suggesting less frequent recharge during the summer.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ECOSER.2022.101503", "year": 2023, "title": "Spatial dynamics of biophysical trade-offs and synergies among ecosystem services in the Himalayas", "abstract": "The production of ecosystem services (ES) is highly dependent on the current state of spatial distribution, pattern of occurrence, and interaction among them, which is barely studied in the Hindu-Kush Himalayas (HKH). Taking a case of a multifunctional landscape in the central HKH region, we aimed to assess the biophysical production possibilities of major ES, their relationships and co-occurrence, and dynamic interactions at different spatial scales. We quantified and mapped six major ES (crop production, timber production, carbon sequestration, soil conservation, water yield, and habitat quality) at two spatial scales: landscape level (functional unit) and watershed level (management unit). Further, we analysed the relationship and interactions among all the possible pairs of the considered ES. All six ES were found to have a positive correlation, except crop production which showed a significant negative correlation with soil conservation. Moreover, we delineated 186 watersheds in the landscape and clustered them based on their biophysical potentials for the supply of ES. Gap statistics from K-means clustering identified three main clusters of watersheds (i.e., agriculture-dominated, poor-performing uplands, and multifunctional). The supply of ES from downstream watersheds was substantially higher than that of the upstream watersheds. We then discussed the interrelationships among ES at various spatial scales and suggested policy instruments for ecosystem management. The relationship among ES shows dynamic forms of spatial distribution, which need to be sustainably managed for minimizing trade-offs and maximizing synergies through the consideration of an integrated watershed management approach, improved agronomy practices, and global climate actions.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ESSD-14-95-2022", "year": 2022, "title": "Multi-year, spatially extensive, watershed-scale synoptic stream chemistry and water quality conditions for six permafrost-underlain Arctic watersheds", "abstract": "Abstract. Repeated sampling of spatially distributed river chemistry can be used to assess the location, scale, and persistence of carbon and nutrient contributions to watershed exports. Here, we provide a comprehensive set of water chemistry measurements and ecohydrological metrics describing the biogeochemical conditions of permafrost-affected Arctic watersheds. These data were collected in watershed-wide synoptic campaigns in six stream networks across northern Alaska. Three watersheds are associated with the Arctic Long-Term Ecological Research site at Toolik Field Station (TFS), which were sampled seasonally each June and August from 2016 to 2018. Three watersheds were associated with the National Park Service (NPS) of Alaska and the U.S. Geological Survey (USGS) and were sampled annually from 2015 to 2019. Extensive water chemistry characterization included carbon species, dissolved nutrients, and major ions. The objective of the sampling designs and data acquisition was to characterize terrestrialaquatic linkages and processing of material in stream networks. The data allow estimation of novel ecohydrological metrics that describe the dominant location, scale, and overall persistence of ecosystem processes in continuous permafrost. These metrics are (1) subcatchment leverage, (2) variance collapse, and (3) spatial persistence. Raw data are available at the National Park Service Integrated Resource Management Applications portal (O'Donnell et al., 2021, https://doi.org/10.5066/P9SBK2DZ) and within the Environmental Data Initiative (Abbott, 2021, https://doi.org/10.6073/pasta/258a44fb9055163dd4dd4371b9dce945).", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.5194/BG-15-3049-2018", "year": 2018, "title": "Reviews and syntheses: Anthropogenic perturbations to carbon fluxes in Asian river systems concepts, emerging trends, and research challenges", "abstract": "Abstract. Human activities are drastically altering water and material flows in river systems across Asia. These anthropogenic perturbations have rarely been linked to the carbon (C) fluxes of Asian rivers that may account for up to 4050 % of the global fluxes. This review aims to provide a conceptual framework for assessing the human impacts on Asian river C fluxes, along with an update on anthropogenic alterations of riverine C fluxes. Drawing on case studies conducted in three selected rivers (the Ganges, Mekong, and Yellow River) and other major Asian rivers, the review focuses on the impacts of river impoundment and pollution on CO2 outgassing from the rivers draining South, Southeast, and East Asian regions that account for the largest fraction of river discharge and C exports from Asia and Oceania. A critical examination of major conceptual models of riverine processes against observed trends suggests that to better understand altered metabolisms and C fluxes in anthropogenic land-water-scapes, or riverine landscapes modified by human activities, the traditional view of the river continuum should be complemented with concepts addressing spatial and temporal discontinuities created by human activities, such as river impoundment and pollution. Recent booms in dam construction on many large Asian rivers pose a host of environmental problems, including increased retention of sediment and associated C. A small number of studies that measured greenhouse gas (GHG) emissions in dammed Asian rivers have reported contrasting impoundment effects: decreased GHG emissions from eutrophic reservoirs with enhanced primary production vs. increased emissions from the flooded vegetation and soils in the early years following dam construction or from the impounded reaches and downstream estuaries during the monsoon period. These contrasting results suggest that the rates of metabolic processes in the impounded and downstream reaches can vary greatly longitudinally over time as a combined result of diel shifts in the balance between autotrophy and heterotrophy, seasonal fluctuations between dry and monsoon periods, and a long-term change from a leaky post-construction phase to a gradual C sink. The rapid pace of urbanization across southern and eastern Asian regions has dramatically increased municipal water withdrawal, generating annually 120 km3 of wastewater in 24 countries, which comprises 39 % of the global municipal wastewater production. Although municipal wastewater constitutes only 1 % of the renewable surface water, it can disproportionately affect the receiving river water, particularly downstream of rapidly expanding metropolitan areas, resulting in eutrophication, increases in the amount and lability of organic C, and pulse emissions of CO2 and other GHGs. In rivers draining highly populated metropolitan areas, lower reaches and tributaries, which are often plagued by frequent algal blooms and pulsatile CO2 emissions from urban tributaries delivering high loads of wastewater, tended to exhibit higher levels of organic C and the partial pressure of CO2 (pCO2) than less impacted upstream reaches and eutrophic impounded reaches. More field measurements of pCO2, together with accurate flux calculations based on river-specific model parameters, are required to provide more accurate estimates of GHG emissions from the Asian rivers that are now underrepresented in the global C budgets. The new conceptual framework incorporating discontinuities created by impoundment and pollution into the river continuum needs to be tested with more field measurements of riverine metabolisms and CO2 dynamics across variously affected reaches to better constrain altered fluxes of organic C and CO2 resulting from changes in the balance between autotrophy and heterotrophy in increasingly human-modified river systems across Asia and other continents.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2016.02.161", "year": 2016, "title": "Recent desiccation of western Great Basin saline lakes: lessons from Lake Abert, Oregon, USA", "abstract": "Although extremely important to migrating waterfowl and shorebirds, and highly threatened globally, most saline lakes are poorly monitored. Lake Abert in the western Great Basin, USA, is an example of this neglect. Designated a critical habitat under the Western Hemisphere Shorebird Reserve Network, the lake is at near record historic low levels and ultra-high salinities that have resulted in ecosystem collapse. Determination of the direct human effects and broader climate controls on Lake Abert illustrates the broader problem of saline lake desiccation and suggests future solutions for restoration of key habitat values. A 65-year time series of lake area was constructed from Landsat images and transformed to lake volume and salinity. Natural (without upstream withdrawals) conditions were calculated from climate and stream flow data, and compared to measured volume and salinity. Under natural conditions the lake would have higher volume and lower salinities because annual water withdrawals account for one-third of mean lake volume. Without withdrawals, the lake would have maintained annual mean salinities mostly within the optimal range of brine shrimp and alkali fly growth. Even during the last two years of major drought, the lake would have maintained salinities well below measured values. Change in climate alone would not produce the recent low lake volumes and high salinities that have destroyed the brine shrimp and alkali fly populations and depleted shorebird use at Lake Abert. Large scale withdrawal of water for direct human use has drastically increased the imbalance between natural runoff and evaporation during periods of drought in saline lakes worldwide but could be offset by establishing an environmental water budget to lay a foundation for the conservation of saline lake habitats under continued threats from development and climate change.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2021.148766", "year": 2021, "title": "Twenty years of change: Land and water resources in the Chindwin catchment, Myanmar between 1999 and 2019", "abstract": "Since 2011, Myanmar has undergone a more rapid socio-economic development, which may substantially have affected land use and land cover (LULC) and water resources. This study investigates the changes in land and water resources of the Chindwin River catchment (114,686.9 km2) in Myanmar over a twenty-year timespan from 1999 to 2019. The main aim of this study is to assess LULC change and evaluate its effects on the water balance and the people in the region. To this end, interviews were conducted, LULC classifications based on multi-temporal multi-spectral satellite data and in-situ ground truth data were created, and a hydrologic model was built. The hydrologic model shows a reasonable performance for daily discharge simulation at the catchment outlet (percent bias between -2 and 13.2, Kling-Gupta Efficiency between 0.75 and 0.76, Nash-Sutcliffe Efficiency between 0.57 and 0.61, RMSE-observations standard deviation between 0.63 and 0.66). The LULC changes detected include a decrease in forest area of about 2%, an increase in shrubland area indicating increased degradation of the forest, an increase in mining areas of 0.38%, an overall decrease in agricultural area (2.1%), but also the presence of new agricultural land pointing toward relocation of agricultural areas and an indication of an increase in settlement areas (1.5%). With the help of the hydrologic model, the most significant hydrologic impacts detected were a decrease in evapotranspiration and an increase in water yield which is correlated with the decrease of forest at the sub-catchment scale (R2 = 0.72 and 0.46, respectively). Moreover, an increase of mining areas contributed to the increase in water yield (R2 = 0.62). Interviews confirm that the identified LULC changes deforestation and increased mining activities contribute to major issues, e.g., water pollution, sedimentation, and changes in the river course.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1002/GRL.50160", "year": 2013, "title": "Inorganic carbon speciation and fluxes in the Congo River", "abstract": "Seasonal variations in inorganic carbon chemistry and associated fluxes from the Congo River were investigated at Brazzaville-Kinshasa. Small seasonal variation in dissolved inorganic carbon (DIC) was found in contrast with discharge-correlated changes in pH, total alkalinity (TA), carbonate species, and dissolved organic carbon (DOC). DIC was almost always greater than TA due to the importance of CO2*, the sum of dissolved CO2 and carbonic acid, as a result of low pH. Organic acids in DOC contributed 11-61% of TA and had a strong titration effect on water pH and carbonate speciation. The CO2* and bicarbonate fluxes accounted for ~57% and 43% of the DIC flux, respectively. Congo River surface water released CO2 at a rate of ~109 mol m-2 yr-1. The basin-wide DIC yield was ~8.84 \u00d7 104 mol km-2 yr-1. The discharge normalized DIC flux to the ocean amounted to 3.11 \u00d7 1011 mol yr-1. The DOC titration effect on the inorganic carbon system may also be important on a global scale for regulating carbon fluxes in rivers.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.WATRES.2021.117427", "year": 2021, "title": "Characterizing 19 thousand Chinese lakes, ponds and reservoirs by morphometric, climate and sediment characteristics", "abstract": "Chinese lakes, including ponds and reservoirs, are increasingly threatened by algal blooms. Yet, each lake is unique, leading to large inter-lake variation in lake vulnerability to algal blooms. Here, we aim to assess the effects of unique lake characteristics on lake vulnerability to algal blooms. To this end, we built a novel and comprehensive database of lake morphometric, climate and sediment characteristics of 19,536 Chinese lakes, including ponds and reservoirs (>0.1 km2). We assessed lake characteristics for nine stratification classes and show that lakes, including ponds and reservoirs, in eastern China typically have a warm stratification class (Tavg>4 C) and are slightly deeper than those in western China. Model results for representative lakes suggest that the most vulnerable lakes to algal blooms are in eastern China where pollution levels are also highest. Our characterization provides an important baseline to inform policymakers in what regions lakes are potentially most vulnerable to algal blooms.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S10661-022-10560-4", "year": 2022, "title": "The possibilities of explicit Striga (Striga asiatica) risk monitoring using phenometric, edaphic, and climatic variables, demonstrated for Malawi and Zambia", "abstract": "Food insecurity continues to affect more than two-thirds of the population in subSaharan Africa (SSA), particularly those depending on rain-fed agriculture. Striga, a parasitic weed, has caused yield losses of cereal crops, immensely affecting smallholder farmers in SSA. Although earlier studies have established that Striga is a constraint to crop production, there is little information on the spatial extent of spread and infestation severity of the weed in some SSA countries like Malawi and Zambia. This study aimed to use remotely sensed vegetation phenological (n = 11), climatic (n = 3), and soil (n = 4) variables to develop a data-driven ecological niche model to estimate Striga (Striga asiatica) spatial distribution patterns over Malawi and Zambia, respectively. Vegetation phenological variables were calculated from 250-m enhanced vegetation index (EVI) timeline data, spanning 2013 to 2016. A multicollinearity test was performed on all 18 predictor variables using the variance inflation factor (VIF) and Pearsons correlation approach. From the initial 18 variables, 12 non-correlated predictor variables were selected to predict Striga risk zones over the two focus countries. The variable start of the season (start of the rainy season) showed the highest model relevance, contributing 26.8% and 37.9% to Striga risk models for Malawi and Zambia, respectively. This indicates that the crop planting date influences the occurrence and the level of Striga infestation. The resultant occurrence maps revealed interesting spatial patterns; while a very high Striga occurrence was predicted for central Malawi and eastern Zambia (mono-cultural maize growing areas), lower occurrence rates were found in the northern regions. Our study shows the possibilities of integrating various ecological factors with a better spatial and temporal resolution for operational and explicit monitoring of Striga-affected areas in SSA. The explicit identification of Striga hotspot areas is crucial for effectively informing intervention activities on the ground.", "labels": [ { "id": 0, "name": "Agriculture" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/HESS-24-2379-2020", "year": 2020, "title": "Modeling inorganic carbon dynamics in the Seine River continuum in France", "abstract": "Abstract. Inland waters are an active component of the carbon cycle where transformations and transports are associated with carbon dioxide (CO2) outgassing. This study estimated CO2 emissions from the human-impacted Seine River (France) and provided a detailed budget of aquatic carbon transfers for organic and inorganic forms, including the in-stream metabolism along the whole Seine River network. The existing process-based biogeochemical pyNuts-Riverstrahler model was supplemented with a newly developed inorganic carbon module and simulations were performed for the recent time period 20102013. New input constraints for the modeling of riverine inorganic carbon were documented by field measurements and complemented by analysis of existing databases. The resulting dissolved inorganic carbon (DIC) concentrations in the Seine aquifers ranged from 25 to 92 mg C L1, while in wastewater treatment plant (WWTP) effluents our DIC measurements averaged 70 mg C L1. Along the main stem of the Seine River, simulations of DIC, total alkalinity, pH and CO2 concentrations were of the same order of magnitude as the observations, but seasonal variability was not always well reproduced. Our simulations demonstrated the CO2 supersaturation with respect to atmospheric concentrations over the entire Seine River network. The most significant outgassing was in lower-order streams while peaks were simulated downstream of the major WWTP effluent. For the period studied (20102013), the annual average of simulated CO2 emissions from the Seine drainage network were estimated at 36499 Gg C yr1. Results from metabolism analysis in the Seine hydrographic network highlighted the importance of benthic activities in headwaters while planktonic activities occurred mainly downstream in larger rivers. The net ecosystem productivity remained negative throughout the 4 simulated years and over the entire drainage network, highlighting the heterotrophy of the basin. Highlights CO2 emission from the Seine River was estimated at 36499 Gg C yr1 with the Riverstrahler model. CO2 riverine concentrations are modulated by groundwater discharge and instream metabolism. CO2 emissions account for 31 % of inorganic carbon exports, the rest being exported as DIC.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1029/2020JC017107", "year": 2021, "title": "Seasonal and Spatial Controls on the Eutrophication-Induced", "abstract": "Our understanding of eutrophication induced acidification in estuaries and coastal oceans is complicated by the seasonally and spatially changing interactions between physical and biochemical drivers. By combining the conservative mixing method and a physical biogeochemical model, we present the seasonal and spatial dynamical analysis of eutrophication induced acidification in the Pearl River Estuary in the northern South China Sea. In summer, the widespread eutrophication induced acidification is regulated by two distinct physical drivers, which are the strengthened stratification in the hypoxia zone and the high turbidity in the Lingdingyang Bay. In the hypoxia zone, eutrophication induced acidification is controlled by the combined effect of benthic remineralization and stratification, while it is dominantly regulated by local biochemical processes (nitrification and respiration) of the whole water column in other regions of the estuary. In winter with the enhanced vertical mixing, the eutrophication induced acidification is still active in the Lingdingyang Bay, and its strength has largely decreased compared with summer condition. While for the hypoxia zone, the eutrophication induced acidification peaks in summer and disappears in winter.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1088/1748-9326/AAF0DE", "year": 2019, "title": "Measuring mangrove carbon loss and gain in deltas", "abstract": "Demand for mangrove forest resources has led to a steady decline in mangrove area over the past century. Land conversions in the form of agriculture, aquaculture and urbanization account for much of the deforestation of mangrove wetlands. However, natural processes at the transition zone between land and ocean can also rapidly change mangrove spread. In this study, we applied a robust field-based carbon inventory and new structural and temporal remote sensing techniques to quantify the magnitude and change of mangrove carbon stocks in major deltas across Africa and Asia. From 2000-2016, approximately 1.6% (12 270 ha) of the total mangrove area within these deltas disappeared, primarily through erosion and conversion to agriculture. However, the rapid expansion of mangroves in some regions during this same period resulted in new forests that were taller and more carbon-dense than the deforested areas. Because of the rapid vertical growth rates and horizontal expansion, new mangrove forests were able to offset the total carbon losses of 5 332 843 Mg C by 44%. Each hectare of new mangrove forest accounted for \u223c84% to \u223c160% of the aboveground carbon for each hectare of mangrove forest lost, regardless of the net change in mangrove area. Our study highlights the significance of the natural dynamics of erosion and sedimentation on carbon loss and sequestration potential for mangroves over time. Areas of naturally regenerating mangroves will have a much larger carbon sequestration potential if the rate of mangrove deforestation of taller forests is curbed.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1038/S41561-018-0265-7", "year": 2018, "title": "Recent global decline in endorheic basin water storages", "abstract": "Endorheic (hydrologically landlocked) basins spatially concur with arid/semi-arid climates. Given limited precipitation but high potential evaporation, their water storage is vulnerable to subtle flux perturbations, which are exacerbated by global warming and human activities. Increasing regional evidence suggests a probably recent net decline in endorheic water storage, but this remains unquantified at a global scale. By integrating satellite observations and hydrological modelling, we reveal that during 20022016 the global endorheic system experienced a widespread water loss of about 106.3 Gt yr1, attributed to comparable losses in surface water, soil moisture and groundwater. This decadal decline, disparate from water storage fluctuations in exorheic basins, appears less sensitive to El NinoSouthern Oscillation-driven climate variability, which implies a possible response to longer-term climate conditions and human water management. In the mass-conserved hydrosphere, such an endorheic water loss not only exacerbates local water stress, but also imposes excess water on exorheic basins, leading to a potential sea level rise that matches the contribution of nearly half of the land glacier retreat (excluding Greenland and Antarctica). Given these dual ramifications, we suggest the necessity for long-term monitoring of water storage variation in the global endorheic system and the inclusion of its net contribution to future sea level budgeting.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1088/1748-9326/ABAAD8", "year": 2020, "title": "Vulnerability of the Caspian Sea shoreline to changes in hydrology and climate", "abstract": "During the past three decades, sea water level (SWL) in the Caspian Sea has declined by about 2 m and sea area has decreased by about 15 000 km2. This has affected coastal communities, the environment and economically important gulfs of the sea (e.g. Dead Kultuk). To assess the effects of coastline change and evaluate zones vulnerable to desiccation, we simulated SWL using total inflow from feeder rivers and precipitation and evaporation over the sea. We determined potential vulnerable areas of the sea over the past 80 years by comparing the minimum and maximum annual water body maps (for 1977 and 1995). We then determined the linear regression between SWL rise and covered potential vulnerable area (CVA), using annual Normalised Difference Water Index (NDWI) maps and SWL data from 1977 to 2018. Combining SWL-CVA regression and SWL simulation model enabled us to determine desiccated areas in different regions of the Caspian Sea due to changes in precipitation, evaporation and total inflow. The results showed that 25 000 km2 of the sea is potentially vulnerable to SWL fluctuations in terms of desiccation, with 70% of this vulnerable area located in Kazakhstan. Potential vulnerable area per kilometre coastline was found to be 6 km2 in Kazakhstan, 4 km2 in Russia and whole of Caspian Sea, 1.5 km2 in Iran, 1 km2 in Azerbaijan and 0.5 km2 in Turkmenistan. The results also indicated that SWL in the Caspian Sea is sensitive to evaporation and that e.g. a 37.5 mm decrease in mean annual net precipitation would lead to a 1875 km2 decrease in the sea area, while a 1 km3 decrease in mean annual inflow would lead to a 1400 km2 decrease in the sea area. Thus the developed framework enabled the spatial consequences of changes in water balance parameters on sea area to be quantified. It can be used to assess future changes in SWL and sea area due to anthropogenic activities and climate change.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1016/J.SCITOTENV.2018.03.038", "year": 2018, "title": "Restoring water quality in the polluted Turag-Tongi-Balu river system, Dhaka: Modelling nutrient and total coliform intervention strategies", "abstract": "River water quality in rapidly urbanising Asian cities threatens to damage the resource base on which human health, economic growth and poverty reduction all depend. Dhaka reflects the challenges and opportunities for balancing these dynamic and complex trade-offs which goals can be achieved through effective policy interventions. There is a serious problem of water pollution in central Dhaka, in the Turag-Tongi-Balu River system in Bangladesh with the river system being one of the most polluted in the world at the moment. A baseline survey of water chemistry and total coliforms has been undertaken and shows dissolved oxygen close to zero in the dry season, high organic loading together with extreme levels of Ammonium-N and total coliform in the water. Models have been applied to assess hydrochemical processes in the river and evaluate alternative strategies for policy and the management of the pollution issues. In particular models of flow, Nitrate-N, Ammonium-N and indicator bacteria (total coliforms) are applied to simulate water quality in the river system. Various scenarios are explored to clean up the river system, including flow augmentation and improved effluent treatment. The model results indicate that improved effluent treatment is likely to have a more significant impact on reducing Ammonium-N and total coliforms than flow augmentation, but a combined strategy would greatly reduce the pollution problems in the Turag-Tongi-Balu River System.", "labels": [ { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.1111/GCBB.12792", "year": 2021, "title": "Assessing hydrologic and water quality effects of land use conversion to", "abstract": "Carinata (Brassica carinata) is an industrial oilseed feedstock for renewable fuels grown as a winter crop in the southeast US, which may provide a new rotation alternative and benefits for water quality. However, the effects of carinata on water quantity and quality at the watershed and local scales are unknown. In this study, we use the Soil and Water Assessment Tool (SWAT) to assess the potential influence of carinata on water balance components, nutrients and sediment loads under plausible future scenarios of land use change in the upper Suwannee River Basin in the Atlantic Coastal Plain Physiographic Region near Tifton in South\u2011Central Georgia. Three future scenarios are considered, including planting stand\u2011alone carinata in winter fallow land every third year, planting stand\u2011alone winter wheat in winter fallow land every third year, and carinata and winter wheat in rotation, one year of winter carinata followed by two years of winter wheat during simulation periods. The results show that under all three future scenarios, surface runoff, sediment, phosphorus, and nitrogen loadings decrease at both watershed and local scales, with higher average monthly reductions in the stand\u2011alone carinata scenario versus the stand\u2011alone winter wheat scenario. When carinata and winter wheat were planted over 36% of the total watershed area, reduction in total sediment, mineral phosphorus, and nitrate loads was ranging from 11.5% to 50.0%. However, when only 12% of the total watershed area was converted to carinata, the simulated reductions ranged from 3.8% to 14.0%. This suggests that the extent of carinata planting is crucial in assessing its hydrologic and water quality benefits. Overall, these results indicate that planting the biofuel carinata as a winter crop can reduce sediment and nutrient loading and provide water quality benefits to downstream waterbodies.", "labels": [ { "id": 19, "name": "Water Quality" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1184/R1/6719885.V1", "year": 2016, "title": "Hydropower Development in the Brazilian Amazon", "abstract": "Brazil plans to meet the majority of its growing electricity demand with new hydropower plants located in the Amazon basin. The governments energy policy forecasts the construction of 55 GW of installed capacity by 2028, with total investments in the range of 100 and 200 billion reais (30 to 60 billion dollars), and the creation 9,000 km2 of artificial reservoirs. However, the construction and operation of large hydropower plants may affect the environment, the local economy, and the population surrounding those projects. Considering the magnitude of the investments and the potential impacts for the Amazon basin, it is crucial to apply policy analysis techniques to support informed decisions about whether the construction of large hydropower plants in the Amazon is the best alternative to supply the additional electricity that Brazil needs, taking into account economic, social, and environmental costs and benefits. Here, I apply three different quantitative policy analysis techniques to assess three major questions related to the construction of hydropower plants in the Amazon region. First, I study the greenhouse gas emissions from hydropower reservoirs in the Amazon. Second, I explore the local socio-economic impacts of building hydropower plants. Finally, I investigate alternative electricity sources that could replace Amazon hydropower reservoirs by modeling the Brazilian electricity network under five capacity expansion scenarios.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.BIOMBIOE.2017.11.020", "year": 2018, "title": "Conversion of grazed pastures to energy cane as a biofuel feedstock alters the emission of GHGs from soils in Southeastern United States", "abstract": "The cultivation of energy cane throughout the Southeastern United States may displace grazed pastures on organic soil (Histosols) to meet growing demands for biofuels. We combined results from a field experiment with a biogeochemical model to improve our understanding of how the conversion of pasture to energy cane during early crop establishment affected soil GHG (CO2, CH4, and N2O) exchange with the atmosphere. GHG fluxes were measured under both land uses during wet, hot and cool, dry times of year, and following a fertilization event. We also simulated the impact of changes in precipitation on GHG exchange. Higher fertilization of cane contributed to greater emission of N2O than pasture during warmer and wetter times of the year. The model predicted that energy cane emitted more nitrogen than pasture during simulated wetter than drier years. The modeled emission factor for N2O was 20 to 30-fold higher than the default value from IPCC (1%), suggesting that the default IPCC value could dramatically underestimate the consequences of this land conversion on the climate system. Predicted soil CH4 and CO2 fluxes were higher in pasture than energy cane, and this difference was not affected by increasing precipitation. Model simulations predicted that soils under first year cane emit more GHGs than pasture, particularly during wet years, but this difference disappeared two years after energy cane establishment. Our results suggest that management practices may be important in determining soil GHG emissions from energy cane on organic soils particularly during the first year of cane establishment.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.RENENE.2021.09.027", "year": 2022, "title": "Solar and wind energy potential assessment at provincial level in Nepal: Geospatial and economic analysis", "abstract": "Renewable energies, such as solar and wind energy, play a critical role in achieving rapid decarbonization to limit global warming by replacing fossil energy. However, lack of knowledge on renewable energy potentials in developing countries is a barrier in making adequate policies to promote these energies. Thus, we have carried out a spatial and economic analysis of solar and wind energy potential at the provincial level for the first time in Nepal. Our analysis is built upon the spatial energy modeling based on technical, geographical, and economic suitability criteria, utilizing open-source geographical information system platforms. A significant amount of renewable energy could be harnessed in Nepal, i.e., up to about 47,628 MW and 1,686 MW from solar and wind energy, respectively. Similarly, Nepal has a co-location potential of about 890 and 267 MW of solar and wind energy. Karnali and Gandaki provinces have the highest solar and wind energy potential due to a large share of suitable locations with good resource quality. We estimate the 10th percentile of Levelized cost of electricity generation of 91 USD/MWh for solar and 46 USD/MWh for wind. Our findings are helpful for the formulation of resource-specific policies of Nepal at a sub-national level.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1088/1748-9326/AC5D9A", "year": 2022, "title": "Cleaner air would enhance Indias annual solar energy production by 628 TWh", "abstract": "Abstract\r\n India has set a target of 100 GW solar installation capacity by the year 2022. However, the loss of solar energy due to environmental factors like air pollution is not properly considered in renewable energy resource assessments. Here we show that India lost 29% of its utilizable global horizontal irradiance potential due to air pollution between 2001 and 2018. The average loss in output incurred by solar power systems with horizontal, fixed-tilt, single-axis, and dual-axis trackers due to air pollution is estimated to be 12%, 26%, 33%, and 41%, respectively, equivalent to a loss of 245835 million USD annually. The successful implementation of the National Clean Air Program and the complete mitigation of household emissions through the supply of cleaner fuel for domestic use and rural electrification would allow India to generate a surplus of 616 TWh of electricity per year from the existing installed solar power capacity in 2018. This translates to an economic benefit of 325845 million USD annually, which is equivalent to the implementation costs of these social programs. Mitigating air pollution would therefore accelerate Indias progress towards achieving its solar energy target at a lesser installation capacity, avoiding additional expenditure for the expansion of the solar energy infrastructure.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.EST.2022.104540", "year": 2022, "title": "Optimum daily operation of a wind-hydro hybrid system", "abstract": "Due to the negative effects of fossil fuels on the environment and health, energy supply is shifting towards renewables. The integration of renewable energy systems is challenging due to the intermittent nature of renewables, however this can be mitigated through storage. Uncertainty in electricity prices in spot markets further complicates the operation of these systems. Pumped storage hydropower is currently the most viable form of large-scale energy storage, and operation of renewable energy systems together with pumped storage hydropower plants is highly efficient. In this study, optimum daily operation strategies are developed for a wind-hydro hybrid system. A long short-term memory network to forecast electricity prices in the day-ahead spot electricity market is coupled with an optimization model to maximize daily revenue. Various scenarios are considered to investigate the benefits of future electricity price estimations. For the wind-hydro hybrid system with 25 MW wind turbine, the net revenue for one-year test period increased 3.5% when forecasted electricity prices with the proposed long short-term memory network is used instead of electricity prices of the previous day. It is observed that increasing the installed capacity of wind turbines compensates for the loss resulting from the poor forecasting of electricity prices; however, the operation schedules of the pump and the hydro turbine do not change when the optimization model uses a simulation duration of one day with hourly time steps.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SCITOTENV.2019.07.073", "year": 2019, "title": "Sources of black carbon in the atmosphere and in snow in the Arctic", "abstract": "We systematically identify sources of black carbon (BC) in the Arctic, including BC in the troposphere, at surface and in snow, using tagged tracer technique implemented in a 3D global chemical transport model GEOS-Chem. We validate modeled BC sources (fossil fuel combustion versus biomass burning) against carbon isotope measurements at Barrow (Alaska), Zeppelin (Norway), Abisko (Sweden), Alert (Canada) and Tiksi (Russia) in the Arctic. The model reproduces the observed annual mean fraction of biomass burning (fbb, %) at the five sites within 20% and the observed and modeled monthly fbb values agree within a factor of two. Model results suggest that fossil fuel combustion is the major source of BC in the troposphere (5094%, vary with sub-regions), at surface (5568%) and in snow (5869%) in the Arctic as annual mean, but biomass burning dominates at certain altitudes (600800 hPa) and during periods of time between April to September. The model shows that BC in the troposphere, in deposition and in snow in different Arctic sub-regions have distinctively different sources and source regions. We find that long-range transport of Asian emissions has a stronger influence on BC in the atmosphere than on BC deposition. In contrast, contributions from Russian and European emissions are larger for BC deposition than for BC in the atmosphere. Specifically, Asian fossil fuel combustion emissions dominate BC loading in all Arctic sub-regions in both winter (Oct.Mar., 3554%) and summer (Apr.Sep., 3456%). For BC deposition, Siberian fossil fuel emissions are the largest contributors in Russia both in winter (62%) and summer (44%), and European fossil fuel emissions dominate in Ny-Alesund (44% in winter) and Troms (71% in winter and 46% in summer). For BC deposition in the North American sector, Asian fossil fuel emissions are the largest contributors in winter (2538%) and North American biomass burning emissions (3872%) dominate in summer.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1007/978-3-030-71044-6_10", "year": 2021, "title": "Different Drivers Behind Corporate Environmental Policies: The Case of the Swedish and Chilean Copper Industry", "abstract": "This chapter represents a comparative study of the emergence of environmental policies in the Chilean and Swedish copper industry. The chapter identifies a number of key factors which helps to explain dissimilar characteristics of actions to protect the environment in both countries as well as the timing for these actions. One key difference identifiedbesides obvious factors such as income levels, political systems and dependency of foreign direct investmentsconcerns the very drivers behind the greening of the industry. While governmental regulation developing from the 1960s represented the primary driver behind the green transformation of Swedish copper industry, it took until the 1990s before the Chilean copper companies started to adopt their first environmental policies ahead of regulation, and called for the Chilean government to act. We suggest that this happened as globalisation took hold from the early 1990s, and foreign companies operating in Chile demanded environmental standards that harmonised with those in the Western world, at the same time as the Chilean industry needed to enhance an environmental reputation in the global market. Thus, while the Swedish industry was much driven by national regulation to invest in cleaner technologies, it was the pressure from globalisation that drove the Chilean industry to clean up their acts.", "labels": [ { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1088/1748-9326/AC8236", "year": 2022, "title": "Forest loss is significantly higher near clustered small dams than single large dams per megawatt of hydroelectricity installed in the Brazilian Amazon", "abstract": "Abstract\r\n \r\n Hydropower in the Brazilian Amazon is a prevalent form of development, but dams have widespread and long-term environmental impacts that include deforestation in the areas surrounding the dams. Small hydropower plants (SHPs) are often perceived as having reduced environmental impacts compared to the large ones. In Brazil, SHPs are licensed by state governments, which have less strict requirements than the federal environmental agency. Brazils definition of small dams has grown with successive increases in the maximum installed capacity from 10 to 30 to 50 megawatts (MW). This expanding loophole has increased the attractiveness of investing in multiple small dams rather than a single large dam, with resulting proliferation of SHPs. Forest dynamics surrounding the clustered SHPs when compared to single large dams are not well documented. In this study, we capitalized on a dense time series of satellite images to quantify and compare forest loss in the regions (over 110 000 km\r\n 2\r\n in area) surrounding 15 SHPs and 7 large dams at multiple watershed and buffer scales in the Brazilian Amazon for nearly two decades (20002018). The landscapes containing SHP clusters had lower cumulative forest loss as compared to those with large dams. However, when deforestation and hydroelectric generating capacity were jointly considered (i.e. forest loss per megawatt installed), we discovered an opposite trend. The regions surrounding the SHP clusters exhibited significant impacts ranging from 1.9 to 2.5 times that of the regions surrounding large dams across 5 km to sub-basin scales. Due to the considerable consequences of SHPs on deforestation, we argue that the rapid expansion of small hydropower should be approached with caution and requires more stringent environmental assessments.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1080/01430750.2022.2137581", "year": 2022, "title": "Techno-economic analysis and wind resource assessment for Odisha, India using reanalysis and 80 m mast measurements: a preliminary assessment for policy-makers", "abstract": "In this work, the relationship between various wind turbine parameters is investigated utilising wind resource data measured at an 80 m measurement mast. Turbine Performance Index (TPI), wind turbulence and direction are investigated to ensure favourable conditions for turbine installation. Economic analysis is performed with reference to the latest Clean Development Mechanism (CDM) registered projects. The life cycle cost and cost of generation for a prospective wind farm are 2691 million INR and 2.97 INR/kWh, respectively. Finally, using five years of NASA MERRA-2 reanalysis data for twelve locations, Weibull parameters and wind power density (WPD) at 50, 80, 120 and 150 m heights are obtained. The installed capacity is 264 MW for selected locations. Energy capture and emission reduction estimates are also computed for all the locations where the highest values of 122 million kWh and 100057 tonnes of CO2 are obtained for Paradeep.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.RENENE.2020.11.081", "year": 2021, "title": "Spatial analysis of indicators affecting the exploitation of shallow geothermal energy at European scale", "abstract": "Shallow Geothermal Energy (SGE) exploited by vertical close loop Ground Source Heat Pumps (GSHP) is a proven, reliable, and widespread renewable heating and cooling technology. However, in many regions there is still a lack of awareness among policy makers and end users, constituting a major constraint to wider deployment of SGE. In order to contribute to its market consolidation, this work focuses on bringing to light relevant spatial information affecting the suitability of SGE exploitation. This information is the result of the systematization of geological, climatic, and environmental open and available data translated into performance indicators. A set of thematic maps was created using Geographic Information Systems (GIS) comprising the European Member States and other European countries. The relative area and the amount of population affected per indicator was spatially analyzed to determine the most common values found and the affected population. The relationship between area percentage and population affected percentage per indicator was also analyzed and allowed to identify the most common indicators values in areas where high energy demands are expected. Additionally, an example of how this data can be used into a Multi-Criteria Decision-Making (MCDM) framework is shown.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S11356-022-18505-7", "year": 2022, "title": "Meteorological factors contributing to organic and elemental carbon concentrations in PM10 near an open-pit coal mine", "abstract": "Variations in the carbonaceous aerosol contents, organic carbon (OC) and elemental carbon (EC), in particulate matter less than 10 m in size (PM10), were analyzed at sites influenced by coal mining in an open-pit mine located in northern Colombia. Samples were collected during different seasonal periods throughout 2015. Meteorological variables for each site were examined during the different seasons. Aerosols were detected using a thermal-optical reflectance protocol method. The highest PM10 concentrations, between the ranges of 28.2 8.2 g m3 and 75.0 36.5 g m3, were recorded during the dry season. However, the highest concentrations of OC (4.814.2 g m3) and EC (2.913.9 g m3) in PM10 were observed during the transition period between the dry and wet seasons. The strong correlation between OC and EC in PM10 (r = 0.61.0) during the transition season indicates a common primary combustion source. High OC (> 8.3 g m3) and EC (> 6.9 g m3) concentrations were associated with low wind speeds (< 2.1 m s1) moving in different directions. Analyses of the sources of atmospheric aerosol pollutants in the mining area in northern Colombia showed that the daily maximum total carbon concentrations were mainly associated with regional atmospheric transport of particulate matter from industrial areas and biomass burning sites located in the territory of Venezuela.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 1, "name": "Air Quality" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ESSD-14-3743-2022", "year": 2022, "title": "Mapping photovoltaic power plants in China using Landsat, random forest, and Google Earth Engine", "abstract": "Abstract. Photovoltaic (PV) technology, an efficient solution for mitigating the impacts of climate change, has been increasingly used across the world to replace fossil fuel power to minimize greenhouse gas emissions. With the world's highest cumulative and fastest built PV capacity, China needs to assess the environmental and social impacts of these established PV power plants. However, a comprehensive map regarding the PV power plants' locations and extent remains scarce on the country scale. This study developed a workflow, combining machine learning and visual interpretation methods with big satellite data, to map PV power plants across China. We applied a pixel-based random forest (RF) model to classify the PV power plants from composite images in 2020 with a 30 m spatial resolution on the Google Earth Engine (GEE). The resulting classification map was further improved by a visual interpretation approach. Eventually, we established a map of PV power plants in China by 2020, covering a total area of 2917 km2. We found that most PV power plants were situated on cropland, followed by barren land and grassland, based on the derived national PV map. In addition, the installation of PV power plants has generally decreased the vegetation cover. This new dataset is expected to be conducive to policy management, environmental assessment, and further classification of PV power plants. The dataset of photovoltaic power plant distribution in China by 2020 is available to the public at https://doi.org/10.5281/zenodo.6849477 (Zhang et al., 2022).", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SOLENER.2022.05.049", "year": 2022, "title": "Development of a solar energy forecasting system for two real solar plants based on WRF Solar with aerosol input and a solar plant model", "abstract": "Regional meteorological models are becoming a generalized tool for solar energy production forecasting, due to their capacity to simulate different types of cloud formations and their interaction with solar radiation. The greater demand for reliable forecasting tools in the energy industry is the motivation for the development of an integrated system that combines the Weather Research and Forecasting atmospheric model package designed to fulfill the needs of solar energy applications (WRF-Solar), with the solaR power plant model. This study focuses on the use and validation of this coupled tool in forecasting the energy production for two real solar plants, one in Spain and another in India. A period of one year for the Spanish emplacement and nine months for the Indian site are simulated with a daily operational forecasting set-up. Aerosol data from the Copernicus Atmosphere Monitoring Service (CAMS) are considered in the calculations, a new capability in WRF-Solar. Power predictions are obtained and compared with real data from the inverters of both plants provided by the operating company. The results show that WRF-Solar obtains accurate forecasts of global, direct, and diffuse radiation and of the ambient temperature that solaR uses as input to predict the energy production of the solar plants. The normalized Mean Annual Errors (NMAE) is 5.18% in the Spanish and 5.59% in the Indian plant for the first day of predictions, demonstrating a reliable performance of the forecasting system in different climate locations. The skill scores for the second day of prediction are also promising, with practically the same errors as the previous day (5.19% and 6.17 for Spain and India respectively). By comparing the model predictions, with and without AOD input during the dustiest days in the Spanish site, the importance of the aerosol effect inclusion is demonstrated with an improvement up to 10% in the energy forecast. These results demonstrate the systems potential both for solar plant operation and energy market applications.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1038/S41893-021-00712-8", "year": 2021, "title": "In-stream turbines for rethinking hydropower development in the Amazon basin", "abstract": "Given growing energy demands and continued interest in hydropower development, it is important that we rethink hydropower to avoid detrimental socioenvironmental consequences of large dams planned in regions such as the Amazon River basin. Here, we show that ~63% of total energy planned to be generated from conventional hydropower in the Brazilian Amazon could be harnessed using in-stream turbines that use kinetic energy of water without requiring storage. At five of the nine selected planned dam sites, the entirety of energy from planned hydropower could be generated using in-stream turbines by using only a fraction of the river stretch that large dams would affect. We find the cost (US$ kWh1) for in-stream turbines to be ~50% of the conventional hydropower cost. Our results have important implications for sustainable hydropower development in the Amazon and worldwide through transition to power generation methods that meet energy needs while minimizing the negative socioenvironment impacts.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ENERGY.2022.123594", "year": 2022, "title": "Two-stage GIS-MCDM based algorithm to identify plausible regions at micro level to install wind farms: A case study of India", "abstract": "Efficiency of the installed wind farms is location-specific. Various research works used the concepts of Geographical Information Systems (GIS) and Multi-criteria-techniques (MCDM) to identify suitable locations. However, research works addressing the micro-level site selection are limited. This study proposes a two-stage GIS-MCDM based algorithm that can identify the plausible regions for installing wind farms at the microscopic level. The developed tool, built on the philosophy of fuzzy Analytical Hierarchy Process (FAHP) and Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), differentiates the regions based on technological, economic, social, and environmental aspects. For demonstration purposes, India is chosen as a study region, implying national-level analysis as stage-1 and state-wise analysis as stage-2. Results suggest that the suitable area for wind farm development in India is approximately 1805131 km2, out of which about 650 km2 is considered as highly suitable, and the following best has 330321 km2. The most suitable locations are in the western and southern parts of India, mainly in Gujarat and Tamil Nadu states. These findings of stage-2 present the hierarchy of plausible regions within each state. The developed tool is the first of its kind, help the decision-maker to extend it for siting solar farms and other energy sources.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.SETA.2021.101062", "year": 2021, "title": "Cost-reliability analysis of hybrid pumped-battery storage for solar and wind energy integration in an island community", "abstract": "This paper presents a mathematical model for estimating the optimal sizing and assessing a standalone hybrid power system's performance entirely based on variable renewable energy sources and coupled with a hybrid energy storage system. This study evaluates how different levels of the main components' capital cost and the loss of power supply probability would affect the cost of energy and the power system's optimal sizing. The case study selected for this study was Ometepe Island in Nicaragua, where the crater lake of an extinct volcano was considered a feasible upper reservoir of a pumped storage hydropower plant, reducing the investments associated with this component. The mathematical formulation considers energy storage losses and gains, and the Pareto efficient solutions of the multi-objective optimization model simultaneously increase reliability, reduce the cost of energy, and minimize curtailment energy. By employing time-series with an hourly resolution, the model allows assessing the impact of the interannual variability of renewable energy sources on the system's performance. As for the case study, the cost of energy obtained from the model results ranges between 0.047/kWh and 0.095/kWh, based on international reference values, and these values match the information available in the literature and other databases.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.EGYR.2022.10.134", "year": 2022, "title": "Assessment of solar and wind energy potential in Far North Queensland", "abstract": "The study aims at selecting suitable sites for solar and wind power developments in remote areas of Far North Queensland (FNQ), Australia. A Geographical Information System (GIS) based multi-criteria approach has been introduced to map potential locations for solar and wind, considering various aspects such as climatic, technical, topography, social, environmental, and economic. The potential of solar and wind energy in suitable land areas has been assessed based on the technologies and site conditions. Analysis of the present study shows that the total suitable areas in selected regions are 57,705.46 km2 (70.56% of total selected land areas) with a power potential of 5,956.14 GW for solar and 58,482.79 km2 (71.51% of total selected land areas) with a power potential of 421.12 GW for wind energy developments. In addition, the study shows that Carpentaria shire has the highest suitable area of 45,689.55 km2 for solar and 46,115.27 km2 for wind, while Injinoo shire has the lowest implementable area of 105.74 km2 for solar and 137.75 km2 for wind. This study provides a significant pathway for parties interested in investing in renewable energy in FNQ.", "labels": [ { "id": 7, "name": "Energy Production/Use" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.EJRH.2022.101304", "year": 2022, "title": "Small hydropower development potential in the Densu River Basin, Ghana", "abstract": "The study investigated potential sites for the development of Small Hydropower Systems (SHP) to augment the existing energy supply in the UDRB. Remote sensing and the Soil and Water Assessment Tool (SWAT) were employed to generate and simulate basin parameters for the hydropower analysis. The energy potential of suitable sites was evaluated using flow duration curves (FDC) and power duration curves (PDC). Results indicate that the upper DRB has potential for small hydropower development with nine sites along the river having an estimated combined firm power of 7.89 MW. The highest hydropower potential sites were located at HP1, HP7, and HP4 with corresponding firm energies of 13.39 GWh, 7.94 GWh, and 6.83 GWh and estimated annual energy production of 28.68 GWh, 14.36 GWh, and 12.68 GWh respectively. Given the adequate spacing distance between sites HP1 and HP4 (11.38 km) and HP4 and HP7 (11.31 km) with a combined annual energy production of 55.72 GWh, a cascade hydropower arrangement of sites HP1, HP4, and HP7 is recommended along the Upper section of the Densu River. However, based on the analysis, these hydropower sites could be developed as a cascade storage hydropower with a 50% or 75% dependability with an installed Francis turbine.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1109/IGARSS39084.2020.9323987", "year": 2020, "title": "Mining Exports and Climate Variability Influencing Grace-Derived Water Storage Trend Estimates in Australia", "abstract": "GRACE and GRACE-FO satellites track the variations of Earth's gravity field since 2002. It is widely assumed that water transfers dominate such measurement, hence GRACE data is routinely used as an estimation of the Total Water Storage Change (TWS). Often, it is disaggregated to infer water storage changes in storage compartments such as glaciers, lakes, or aquifers. Here we show that, in Australia, two considerations are crucial for interpreting GRACE data. First, iron ore mining exports impact the gravity signal in the Northwest at a rate of -425 Mt/yr. Second, given the non-stationarity of the Australian climate, 15 years of gravity data are not sufficient to fully capture the climate variability and to depict a long-term vision of water storage trends for resilient water storage compartments such as large aquifers.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/978-3-030-76624-5_29", "year": 2021, "title": "Monitoring Wildfires in Forest and Grassland Related to Sugarcane Burning with Geotechnologies", "abstract": "Sugarcane is an important agro-industrial crop for the production of food, biofuels and bioproducts. However, the agricultural management of this crop generates significant socioeconomic and environmental impacts. The burning of sugarcane-cultivated fields, a practice used to facilitate planting and harvesting, is used extensively in Mexico and other sugarcane-producing countries but causes nitrogen volatilization, a decrease in microorganisms and organic material in the soils, and increased wildfires in forest ecosystems and respiratory health problems in surrounding areas. Academic evidence has shown that sugarcane harvesting with biomass burning is associated with the generation of GHGs and an increase in extreme weather conditions, such as rising temperatures and more frequent and prolonged droughts. These effects, in turn, have modified the structure of vegetation communities and ecosystems, as well as affected carbon and water cycles and the regional climate system and therefore the productivity and profitability of crops. The objective of this work was to determine the distribution patterns of wildfires and their impact on forest and rainforest areas near sugarcane crops in the Huasteca Potosina region, Mexico, during the period 20102020, using high and low spatial resolution satellite images. MODIS (Moderate Resolution Imaging Spectroradiometer) MCD64A1 satellite images were used to evaluate sugarcane-burnt areas impacted by drought to assess thermal anomalies, whereas Landsat 8 OLI images were used to calculate and monitor burned areas, both in sugarcane crops and in perimeter forests and rainforests. The products generated will serve to demonstrate the impact of sugarcane burning and help establish proposals for agroforestry sustainability to prevent, monitor, control and manage future wildfires.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-21-14019-2021", "year": 2021, "title": "Exceptional loss in ozone in the Arctic winter/spring of 2019/2020", "abstract": "Abstract. Severe vortex-wide ozone loss in the Arctic would expose both ecosystems and several millions of people to unhealthy ultraviolet radiation. Adding to these worries, and extreme events as the harbingers of climate change, exceptionally low ozone with column values below 220 DU occurred over the Arctic in March and April 2020. Sporadic occurrences of low ozone with less than 220 DU at different regions of the vortex for almost 3 weeks were found for the first time in the observed history in the Arctic. Furthermore, a large ozone loss of about 2.03.4 ppmv triggered by an unprecedented chlorine activation (1.52.2 ppbv) matching the levels occurring in the Antarctic was also observed. The polar processing situation led to the first-ever appearance of loss saturation in the Arctic. Apart from these, there were also ozone-mini holes in December 2019 and January 2020 driven by atmospheric dynamics. The large loss in ozone in the colder Arctic winters is intriguing and demands rigorous monitoring of the region.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/ESSD-13-827-2021", "year": 2021, "title": "A high-resolution unified observational data product of mesoscale convective systems and isolated deep convection in the United States for 2004\u20132017", "abstract": "Abstract. Deep convection possesses markedly distinct properties at different spatiotemporal scales. We present an original high-resolution (4 km, hourly) unified data product of mesoscale convective systems (MCSs) and isolated deep convection (IDC) in the United States east of the Rocky Mountains and examine their climatological characteristics from 2004 to 2017. The data product is produced by applying an updated Flexible Object Tracker algorithm to hourly satellite brightness temperature, radar reflectivity, and precipitation datasets. Analysis of the data product shows that MCSs are much larger and longer-lasting than IDC, but IDC occurs about 100 times more frequently than MCSs, with a mean convective intensity comparable to that of MCSs. Hence both MCS and IDC are essential contributors to precipitation east of the Rocky Mountains, although their precipitation shows significantly different spatiotemporal characteristics. IDC precipitation concentrates in summer in the Southeast with a peak in the late afternoon, while MCS precipitation is significant in all seasons, especially for spring and summer in the Great Plains. The spatial distribution of MCS precipitation amounts varies by season, while diurnally, MCS precipitation generally peaks during nighttime except in the Southeast. Potential uncertainties and limitations of the data product are also discussed. The data product is useful for investigating the atmospheric environments and physical processes associated with different types of convective systems; quantifying the impacts of convection on hydrology, atmospheric chemistry, and severe weather events; and evaluating and improving the representation of convective processes in weather and climate models. The data product is available at https://doi.org/10.25584/1632005 (Li et al., 2020).", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2021GL097617", "year": 2022, "title": "What's in a name? On the use and significance of the term \u201cpolar vortex\u201d", "abstract": "Mainstream and popular science media are rife with misunderstandings about what a \"polar vortex\" is. The term most aptly describes the stratospheric polar vortex, a single feature dominating the cool-season circulation from \u223c15-50 km. Regional jet stream variations dominate the tropospheric circulation, which is not well-described as a polar vortex; indeed, there is no single consistent definition of a tropospheric polar vortex in the literature. Stratospheric polar vortex disturbances profoundly influence extreme weather events, including cold air outbreaks (CAOs). How the stratospheric polar vortex affects tropospheric jets, whose local excursions drive CAOs, is not fully understood. Public-facing parts of publications describing research on this topic are not always clear about how the \"polar vortex\" is defined; greater clarity could improve communications both within the community and with non-specialist audiences.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/978-3-642-32235-8_5", "year": 2013, "title": "Climate Archives", "abstract": "After a brief introduction into the marine carbon cycle, the calcite compensation theory and the rain-ratio hypothesis, two theories that may explain glacial to interglacial changes in atmospheric CO2 concentrations are presented. The validity of these theories in the Southern Ocean is tested with B/Ca-reconstructed carbonate ion concentrations of deep and intermediate waters. Deglacial [CO32] excursions reveal a close relationship between changes in the oceanic inorganic carbon system and atmospheric CO2, which follow the predictions of the calcite compensation theory on glacial-interglacial timescales. Short-termed [CO32] variations are likely due to the influence of the biological pump and/or changes in circulation patterns.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/GCB.16031", "year": 2022, "title": "Seasonal to decadal spatiotemporal variations of the global ocean carbon sink", "abstract": "AbstractThe global ocean has absorbed approximately 30% of anthropogenic CO2 since the beginning of the industrial revolution. However, the spatiotemporal evolution of this important global carbon sink varies substantially on all timescales and has not yet been well evaluated. Here, based on a reconstructed observationbased product of surface ocean pCO2 and airsea CO2 flux (the MPISOMFFN method), we investigated seasonal to decadal spatiotemporal variations of the ocean CO2 sink during the past three decades using an adaptive data analysis method. Two predominant variations are modulated annual cycles and decadal fluctuations, which account for approximately 46% and 25% of all extracted components, respectively. Although the whole summer to nonsummer seasonal difference pattern is determined by the Southern Ocean, the nonsummer CO2 sink at midlatitudes in both hemispheres shows an increasing trend (a total increase of approximately 1.0 PgC during the period 19822019), while it is relatively stable in summer. On decadal timescales for the global ocean carbon sink, unlike the weakening decade (19901999) and the reinvigoration decade (20002009) in which the Southern Ocean plays the dominant role, the reinforcement decade (20102019) is mainly the result from the weakening source effect in the equatorial Pacific Ocean. Our results suggest that except for the Southern Ocean's role in the global ocean carbon sink, the strengthening nonsummer's sink at midlatitudes in both hemispheres and the decadal or longer timescales of equatorial Pacific Ocean dynamics should be fully considered in understanding the oceanic carbon cycle on a global scale.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2021GL094183", "year": 2021, "title": "Recent Increases in Exposure to Extreme Humid-Heat Events", "abstract": "Extreme heat research has largely focused on dry-heat, while humid-heat that poses a substantial threat to human-health remains relatively understudied. Using hourly high-resolution ERA5 reanalysis and HadISD station data, we provide the first spatially comprehensive, global-scale characterization of the magnitude, seasonal timing, and frequency of dry- and wet-bulb temperature extremes and their trends. While the peak dry- and humid-heat extreme occurrences often coincide, their timing differs in climatologically wet regions. Since 1979, dry- and humid-heat extremes have become more frequent over most land regions, with the greatest increases in the tropics and Arctic. Humid-heat extremes have increased disproportionately over populated regions (\u223c5.0 days per-person per-decade) relative to global land-areas (\u223c3.6 days per-unit-land-area per-decade) and population exposure to humid-heat has increased at a faster rate than to dry-heat. Our study highlights the need for a multivariate approach to understand and mitigate future harm from heat stress in a warming world.", "labels": [ { "id": 12, "name": "Heat" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S00024-019-02360-8", "year": 2020, "title": "Case study of a convective cluster over the rain shadow region of Western Ghats using multi-platform observations and WRF model", "abstract": "Unique observational features of a convective cluster, occurred on 12-Sept-2015, over the rain shadow region in the leeward side of Western Ghats have been presented in this study. The synoptic environment had preconditioned the formation of a convergence zone over the study area. Moisture transport from the Arabian Sea was responsible for the moistening in the lower layers. Boundary layer convective thermals contributed to middle level moistening and subsequent onset of the cloud cluster was accompanied by a sudden surge of moist and warm air into the middle troposphere, and subsequent lifting of freezing level (FL) and wet bulb temperature zero (WBT0) levels. Sudden changes in the FL and WBT0 levels in association with the gust front prior to the initiation of the cloud system has been documented with high-resolution measurements using microwave radiometer and wind profiler. Thermodynamical parameters from radiometer illustrate the percussive conditions for formation of the cloud system. The cloud cluster had resulted in 25.50 mm rainfall, attributing to ~ 91% of convective rain. Intense fall velocity (1012 ms1) was noted up to ~ 7 km during the convective rain and the fall velocity was reduced to ~ 7 ms1 (below the melting layer) during the stratiform counterpart. The cloud system was forecasted using WRF model (version 3.6.1), which was reproduced reasonably well as in the observations and the model output has been analyzed to understand the morphology of the system. The features such as formation of a cold pool, initiation of convective rainfall from the system were well forecasted by the model. Microphysical characteristics of the cloud cluster have also been examined. Riming was the dominant microphysical process within the convective regime. A major contribution to precipitation was from melting of ice hydrometeors especially graupel and snow was noted. Deep warm layer and associated production of supercooled liquid by the lifting of liquid water above the freezing level in updrafts exceeding 15 ms1 was important for the production of a mixed-phase cloud system. Vapor deposition and aggregation process was noted in the stratiform/anvil counterpart, which also contained mixed phase hydrometeors, primarily of snow.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/IJERPH17092993", "year": 2020, "title": "Spatial Distribution of Land Surface Temperatures in Kuwait: Urban Heat", "abstract": "The global rise of urbanization has led to the formation of surface urban heat islands and surface urban cool islands. Urban heat islands have been shown to increase thermal discomfort, which increases heat stress and heat-related diseases. In Kuwait, a hyper-arid desert climate, most of the population lives in urban and suburban areas. In this study, we characterized the spatial distribution of land surface temperatures and investigated the presence of urban heat and cool effects in Kuwait. We used historical Moderate-Resolution Imaging Spectroradiometer (MODIS) Terra satellite 8-day composite land surface temperature (LST) from 2001 to 2017. We calculated the average LSTs of the urban/suburban governorates and compared them to the average LSTs of the rural and barren lands. We repeated the analysis for daytime and nighttime LST. During the day, the temperature difference (urban/suburban minus versus governorates) was 1.1 C (95% CI; 1.2, 1.00, p < 0.001) indicating a daytime urban cool island. At night, the temperature difference (urban/suburban versus rural governorates) became 3.6 C (95% CI; 3.5, 3.7, p < 0.001) indicating a nighttime urban heat island. In light of rising temperatures in Kuwait, this work can inform climate change adaptation efforts in the country including urban planning policies, but also has the potential to improve temperature exposure assessment for future population health studies.", "labels": [ { "id": 12, "name": "Heat" } ] }, { "doi": "10.1029/2020JC016643", "year": 2020, "title": "Barrier layers in a high\u2010resolution model in the eastern tropical Pacific", "abstract": "This study examines salinity barrier layers (BLs) in the eastern tropical North Pacific in the region of the Salinity Processes in the Upper ocean Regional Studies-2 field campaign. We utilize a high-resolution numerical model to study BLs and their relationship to frontal features and small-scale ocean variability, focusing on two specific events. One is associated with a large outbreak of BL presence near 7\u00b0N along 125\u00b0W. The other is a relatively isolated but persistent BL that forms near 13\u00b0N, again along 125\u00b0W. In both cases we find that the BL is proximate to a salinity frontal feature in which isohalines tilt toward the fresh side of the front at its base. The BLs studied are associated with divergent flow at the surface on the fresh side of the front and convergent flow on the salty side. Tilting of the front is invoked to explain this, with an additional mechanism involving a vertical circulation which causes the base of the front to tilt preferentially.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2022EA002287", "year": 2022, "title": "An Overview of Aerosol Properties in Clear and Cloudy Sky Based on", "abstract": "A full understanding of the climatological properties of aerosols is an important step towards characterizing their effects on climate. Utilizing the observations from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations, we study cloud-free and cloudy aerosol properties with attention on aerosol and cloud layer relative vertical positions. On a global scale, the cloud-free aerosols account for about 56% of all detected aerosols with a mean optical depth (\u03c4\u00afa) and mean uncertainty of 0.135 \u00b1 0.047. The cloudy aerosols, accounting for 44%, have a larger \u03c4\u00afa and larger mean uncertainty of 0.143 \u00b1 0.074 compared to the cloud-free aerosols. The above-cloud aerosols (\u223c4%), primarily composed of elevated smoke, dust/volcanic ash and polluted dust, have a much smaller \u03c4\u00afa of (0.056 \u00b1 0.038). The below-cloud aerosols (\u223c21%) have \u03c4\u00afa \u223c 0.165 \u00b1 0.087. The below-cloud and cloud-free aerosols show close \u03c4a probability density distributions and similar aerosol types, indicating that cloud-free aerosol climatologies from passive sensors are likely representative of all-sky conditions. In addition, about 27% of the detected aerosol profiles are found to have cloud layers vertically connected to the detected aerosol layers. The lidar backscatter profiles of these aerosols have larger median values than the cloud-free, above-cloud and below-cloud aerosols. The seasonal variations of the cloud-free and the cloudy aerosols significantly vary with regions. Our results imply that quantifying the impact of clouds, particularly cirrus due to the wide coverage of cirrus-aerosol overlap, on aerosol direct radiative effect is crucial to assess aerosols' roles in the Earth-climate system.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2022GL098539", "year": 2022, "title": "Fine\u2010Scale Geothermal Heat Flow in Antarctica Can Increase Simulated Subglacial Melt Estimates", "abstract": "Antarctic geothermal heat flow (GHF) affects the thermal regime of ice sheets and simulations of ice and subglacial meltwater discharge to the ocean, but remains poorly constrained. We use an ice sheet model to investigate the impact of GHF anomalies on subglacial meltwater production in the Aurora Subglacial Basin, East Antarctica. We find that spatially-variable GHF fields produce more meltwater than a constant GHF with the same background mean, and meltwater production increases as the resolution of GHF anomalies increases. Our results suggest that model simulations of this region systematically underestimate meltwater production using current GHF models. We determine the minimum basal heating required to bring the basal ice temperature to the pressure melting point, which should be taken together with the scale-length of likely local variability in targeting in-situ GHF field campaigns.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.ENERGY.2017.01.084", "year": 2017, "title": "Heat coupling of the pan-European vs. regional electrical grid with excess renewable energy", "abstract": "The feasibility of heating sector integration into future highly renewable electrical grid is examined for a regional and pan-European network. A novel geographical weather dependent model for calculating the heat demand using a temporal resolution of an hour with a spatial resolution of 40 40 km2 and an optimized solution for the utilization of excess renewable generation with least energy needs is presented. Heating sector is modeled and coupled separately with two different heat coupling models, heat-pump coupling and electric-resistance coupling, both having heat-storage and gas-boiler. Results show coupling with the regional network requires least heat-storage capacity and coupling with an individual country network requires the least gas-boiler capacity. However, coupling with the pan-European network results in least balancing energy needs. It is found that heat-pump coupling provides more benefit than the electric-resistance coupling, with 4 times more heat-storage energy and 38% less requirement for the gas-boiler energy. Optimum energy mix between the heat-storage energy and gas-boiler energy suggests that the present amount of excess generation is not enough to fully support the heating sector, but if the renewable energy generation is increased by 50% then heat-storage will play an important role.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-21-6053-2021", "year": 2021, "title": "Impact of smoke and non-smoke aerosols on radiation and low-level clouds over the southeast Atlantic from co-located satellite observations", "abstract": "Abstract. Data derived from instruments on board the CloudAerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) and CloudSat satellites as well as meteorological parameters from reanalysis are used to explore situations when moist aerosol layers overlie stratocumulus clouds over the southeast Atlantic during the biomass burning season (June to October). To separate and quantify the impacts of aerosol loading, aerosol type, and humidity on the radiative fluxes (including cloud top cooling), the data are split into different levels of aerosol and moisture loadings. The aerosol classification available from the CALIPSO products is used to compare and contrast situations with pristine air, with smoke, and with other (non-smoke) types of aerosols. A substantial number of cases with non-smoke aerosols above clouds are found to occur under similar meteorological conditions to the smoke cases. In contrast, the meteorology is substantially different for the pristine situations, making a direct comparison with the aerosol cases ambiguous. The moisture content is enhanced within the aerosol layers, but the relative humidity does not always increase monotonously with increasing optical depth. Shortwave (SW) heating rates within the moist aerosol plumes increase with increasing aerosol loading and are higher in the smoke cases compared to the non-smoke cases. However, there is no clear correlation between moisture changes and SW absorption. Cloud top cooling rates do not show a clear correlation with moisture within the overlying aerosol layers due to the strong variability of the cooling rates caused by other meteorological factors (most notably cloud top temperature). No clear influence of aerosol type or loading on cloud top cooling rates is detected. Further, there is no correlation between aerosol loading and the thermodynamic structure of the atmosphere nor the cloud top height.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.JASTP.2018.08.008", "year": 2018, "title": "Thunderstorm induced changes in near-surface O3, NOx and CH4 and associated boundary layer meteorology over a tropical coastal station", "abstract": "The paper presents four cases of the response of near-surface O3, NOx and CH4 to thunderstorm activity at a tropical coastal site in India, occurred during pre-monsoon and post-monsoon seasons. The associated changes in boundary layer meteorology in terms of temperature, relative humidity (RH), wind and boundary layer height (BLH) are also examined. The meteorological parameters like temperature and RH respond very fast depicting changes during the initial phase of the thunderstorm activity, whereas a delayed response is observed in the wind direction (changing from the sea breeze to land breeze) and collapse of the BLH (11:30 h delay) at the mature phase of the activity. Associated with the thunderstorm activity, significant changes were observed in the mixing ratios of the near-surface O3, NOx and CH4. An increase in NOx (5.28.7 ppbv) and CH4 (36.7134.6 ppbv) and reduction in O3 (9.918.8 ppbv) were recorded at the mature phase of the thunderstorm. The rise in NOx is attributed to the combined effect of thunderstorm activity and wind reversal whereas that in CH4 is attributed to the wind reversal and associated change in air mass. A post activity increase is observed in mixing ratio of O3 in all the four cases. This is attributed to the downdrafts characteristic of the dissipation phase of thunderstorm activity which brings in O3 rich upper air down.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2021EA001813", "year": 2021, "title": "Lightning geolocation and flash rates from LF radio observations during the RELAMPAGO field campaign", "abstract": "The lightning data products generated by the low-frequency (LF) radio lightning locating system (LLS) deployed during the Remote sensing of Electrification, Lightning, and Mesoscale/Microscale Processes with Adaptive Ground Observation (RELAMPAGO) field campaign in Argentina provide a valuable data set to research the lightning evolution and characteristics of convective storms that produce high-impact weather. LF LLS data sets offer a practical range for mesoscale studies, allowing for the observation of lightning characteristics of storms such as mesoscale convective systems or large convective lines that travel longer distances which are not necessarily staying in range of regional VHF-based lightning detection systems throughout their lifetime. LF LLSs also provide different information than optical space-borne lightning detectors. Lightning measurements exclusive to LF systems include discharge peak current, lightning polarity, and lightning type classification based on the lightning-emitted radio waveform. Furthermore, these measurements can provide additional information on flash rates (e.g., positive cloud-to-ground flash rate) or narrow bipolar events which may often be associated with dynamically intense convection. In this article, the geolocation and data processing of the LF data set collected during RELAMPAGO is fully described and its performance characterized, with location accuracy better than 10 km. The detection efficiency (DE) of the data set is compared to that of the Geostationary Lightning Mapper, and spatiotemporal DE losses in the LF data set are discussed. Storm case studies on November 10, 2018, highlight the strengths of the data set, which include robust flash clustering and insightful flash rate and peak current measures, while illustrating how its limitations, including DE losses, can be managed.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2016GL069581", "year": 2016, "title": "Air-sea exchange of carbon dioxide in the Southern Ocean and Antarctic", "abstract": "Direct carbon dioxide flux measurements using eddy covariance from an icebreaker in the high-latitude Southern Ocean and Antarctic marginal ice zone are reported. Fluxes were combined with the measured water-air carbon dioxide partial pressure difference (\u0394pCO2) to compute the air-sea gas transfer velocity (k, normalized to Schmidt number 660). The open water data showed a quadratic relationship between k (cm h-1) and the neutral 10 m wind speed (U10n, m s-1), kopen = 0.245 U10n2 + 1.3, in close agreement with decades old tracer-based results and much lower than cubic relationships inferred from previous open ocean eddy covariance studies. In the marginal ice zone, the effective gas transfer velocity decreased in proportion to sea ice cover, in contrast with predictions of enhanced gas exchange in the presence of sea ice. The combined open water and marginal ice zone results affect the calculated magnitude and spatial distribution of Southern Ocean carbon flux.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/JOC.6299", "year": 2020, "title": "Changes in winter stationary wave activity during weak mid-latitude and Arctic thermal contrast period", "abstract": "Using reanalysis data set, this study investigates the changes in winter mean stationary wave activity, when the thermal contrast between mid\u2011latitude and Arctic is weak. The mid\u2011latitude and Arctic thermal contrast was stronger during 1986\u20132003 and weaker during 1966\u20131985 and 2004\u20132017. The changes in stationary wave characteristics are studied based on the stationary wave activity flux (SWAF). Compare to the period when the contrast was stronger (1986\u20132003), both the convergence of SWAF and stationary wave amplitude have been enhanced in the Northern part of Eurasia during the periods 1966\u20131985 and 2004\u20132017. We further proposed that a weak mid\u2011latitude/Arctic thermal contrast provides a good condition for the enhancement of the stationary wave activity. The weak mid\u2011latitude\u2011Arctic thermal contrast is conducive to the enhancement of blocking frequency around Ural Mountains, which may contribute partly to the increase in stationary wave amplitude and associated changes in the SWAF. Furthermore, the weak thermal contrast is associated with the decrease in baroclinicity and synoptic\u2011scale eddy activity, which in turn contributes to the generation of stationary waves via eddy feedback processes.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.GLOPLACHA.2020.103192", "year": 2020, "title": "Water vapor variability in the Atacama Desert during the 20th century", "abstract": "This study focuses on integrated water vapor (IWV) which is the main source for precipitation, fog and dew formation in the Atacama Desert in northern Chile. In order to study its long-term variability, a consistent meteorological record is needed. Here, we utilize the European Centre for Medium-Range Weather Forecasts' reanalysis ERA-20C which provides IWV among other atmospheric variables over the course of the entire 20th century (19002010). In this two fold study, we first present a validation of ERA-20C IWV for the Atacama and the bordering southeast Pacific region. Comparisons to satellite observations, i.e. the Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite data record and the Moderate Resolution Imaging Spectroradiometer measurements, for overlapping time periods prove the suitability of ERA-20C to study IWV variability. Assessment of the observation feedback in ERA-20C reveals a higher uncertainty for the beginning of the 20th century when fewer observations are assimilated. Nevertheless, departures of the assimilated observations do not show a systematic bias in space or time supporting suitability of ERA-20C for long-term investigations. In the second part of the study, we describe the IWV variability over the course of the 20th century. Deviations from the long-term mean greater than 30% are found on an inter-annual time scale over the continental Atacama. Furthermore, we investigate potential drivers of the IWV variability such as the Pacific Decadal Oscillation (PDO) and the El Nino Southern Oscillation (ENSO) phenomenon. The relationship between the local IWV and these large scale indices depends on region and season. For instance, during austral summer, La Nina conditions yield overall greater IWV variability in the Atacama allowing both drier and even more pronounced wetter extremes than El Nino conditions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2018JC014275", "year": 2018, "title": "Argo Observations of the Deep Mixing Band in the Southern Ocean: A", "abstract": "The Southern Ocean plays an important role in mediating oceanic uptake of CO2 and heat due to a strong meridional overturning circulation. Gridded Argo float data for 2004-2017 were used to evaluate subsurface processes at the mixed layer depth (MLD) that occur in a narrow deep mixing band. Shifts in the value of the Turner Angle at the MLD indicate that early in the season the MLD deepens slowly as it encounters and is stabilized by a subsurface salt maximum. By September mixing has penetrated this salinity feature and the rate of deepening is faster once the MLD is deeper than the depth where the maximum salinity occurs ( 150-200 m). This distinctive salinity layer is the result of surface Ekman transport of fresh water from the south and subsurface advection of high-salinity water from the north. Two configurations of the Community Earth System Model (CESM) ocean-ice forced hindcast experiments\u2014one with 1\u00b0 and the other with 0.1\u00b0 horizontal resolution (Parallel Ocean Program low and high resolutions [POP-LR and POP-HR], respectively)\u2014are compared with the Argo data for 2005-2009. POP-LR has a shallow MLD bias common to many Fifth Coupled Models Intercomparison Project (CMIP5) models, while POP-HR has a mix of deep and shallow MLD biases. While both models were able to replicate the large-scale processes leading to formation of a high-salinity layer, the salinity feature in POP-HR is too strong and deep. Neither model was able to replicate the vertical mixing processes leading to penetration of the subsurface salt maximum.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2019GL086207", "year": 2020, "title": "Strong Precipitation Suppression by Aerosols in Marine Low Clouds", "abstract": "The adjustment of cloud amount to aerosol effects occurs to a large extent in response to the aerosol effect on precipitation. Here the marine boundary layer clouds were studied by analyzing the dependence of rain intensity measured by Global Precipitation Measurement on cloud properties. We showed that detectable rain initiates when the drop effective radius at the cloud top (re) exceeds 14 \u03bcm, and precipitation is strongly suppressed with increasing cloud drop concentration (Nd), which contributes to the strong dependence of cloud amount on aerosols. The rain rate increases sharply with cloud thickness (CGT) and re when re > 14 \u03bcm. The dependence of rain rate on re and CGT presents a simple framework for precipitation susceptibility to aerosols, which explains other previously observed relationships. We showed that sorting data by CGT and using alternative cloud condensation nuclei proxy rather than aerosol optical depth are critical for studying aerosol-cloud-precipitation interactions.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1038/S41467-020-14449-Z", "year": 2020, "title": "Enhanced eddy activity in the Beaufort Gyre in response to sea ice loss", "abstract": "The Beaufort Gyre freshwater content has increased since the 1990s, potentially stabilizing in recent years. The mechanisms proposed to explain the stabilization involve either mesoscale eddy activity that opposes Ekman pumping or the reduction of Ekman pumping due to reduced sea iceocean surface stress. However, the relative importance of these mechanisms is unclear. Here, we present observational estimates of the Beaufort Gyre mechanical energy budget and show that energy dissipation and freshwater content stabilization by eddies increased in the late-2000s. The loss of sea ice and acceleration of ocean currents after 2007 resulted in enhanced mechanical energy input but without corresponding increases in potential energy storage. To balance the energy surplus, eddy dissipation and its role in gyre stabilization must have increased after 2007. Our results imply that declining Arctic sea ice will lead to an increasingly energetic Beaufort Gyre with eddies playing a greater role in its stabilization.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1525/ELEMENTA.2020.00108", "year": 2021, "title": "Sediment-laden sea ice in southern Hudson Bay: Entrainment, transport, and biogeochemical implications", "abstract": "During a research expedition in Hudson Bay in June 2018, vast areas of thick (>10 m), deformed sediment-laden sea ice were encountered unexpectedly in southern Hudson Bay and presented difficult navigation conditions for the Canadian Coast Guard Ship Amundsen. An aerial survey of one of these floes revealed a maximum ridge height of 4.6 m and an average freeboard of 2.2 m, which corresponds to an estimated total thickness of 18 m, far greater than expected within a seasonal ice cover. Samples of the upper portion of the ice floe revealed that it was isothermal and fresh in areas with sediment present on the surface. Fine-grained sediment and larger rocks were visible on the ice surface, while a pronounced sediment band was observed in an ice core. Initial speculation was that this ice had formed in the highly dynamic Nelson River estuary from freshwater, but 18O isotopic analysis revealed a marine origin. In southern Hudson Bay, significant tidal forcing promotes both sediment resuspension and new ice formation within a flaw lead, which we speculate promotes the formation of this sediment-laden sea ice. Historic satellite imagery shows that sediment-laden sea ice is typical of southern Hudson Bay, varying in areal extent from 47 to 118 km2 during June. Based on an average sediment particle concentration of 0.1 mg mL1 in sea ice, an areal extent of 51,924 km2 in June 2018, and an estimated regional end-of-winter ice thickness of 1.5 m, we conservatively estimated that a total sediment load of 7.8 106 t, or 150 t km2, was entrained within sea ice in southern Hudson Bay during winter 2018. As sediments can alter carbon concentrations and light transmission within sea ice, these first observations of this ice type in Hudson Bay imply biogeochemical impacts for the marine system.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1016/J.POLAR.2020.100599", "year": 2021, "title": "Increasing dust emission from ice free terrain in southeastern Greenland since 2000", "abstract": "Mineral dust plays a key role in both local and global climates. At high latitudes, atmospheric dust can affect ice-nuclei formation, and surface dust can reduce the albedo as well as increase subsequent ice melting. As a proxy for past climate, mineral dust is preserved in ice cores, but few studies have examined deposited dust in ice cores during the Anthropocene, especially after 2000. We measured dust concentrations in an ice core at the southeastern dome in Greenland (SE-Dome), and reconstructed the annual and seasonal dust fluxes during 19602014. We find the annual average flux during 19602014 to be 34.8 13.5 mg m2 yr1, a value about twice that of ice cores further inland. The more recent part of that period, 20002014, has the higher annual flux of 46.6 16.2 mg m2 yr1. The annual and autumn dust fluxes highly correlate with air temperature in Tasiilaq (r = 0.61 and 0.50, respectively), a coastal location in southeastern Greenland. Our results suggest that the local dust emissions at the coastal region are increasing due to a decreasing seasonal snow-cover area arising from coastal Greenland warming after 2000.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S12524-022-01651-3", "year": 2023, "title": "Spatio-temporal Analyses of Sea Ice Conditions over Two Seas of Arctic Ocean", "abstract": "Sea ice conditions over the Arctic can be studied remotely using various satellites. In the current paper, two seas of the Arctic, Beaufort and Laptev are considered. The difference in the sea ice conditions of Beaufort and Laptev is separately observed using the parameters; Sea Ice Area, Concentration and Thickness for the span of 20102021. In order to understand the peripheral and lateral condition of sea ice in a given region for a given time, we have attempted to understand each derivable product of the sea ice spatially and temporally throughout its life cycle. It has been found that the Laptev which is a major warehouse of arctic sea ice with an average outflow of 483,000 km2 per year is found to have a low range of Sea Ice Area and Thickness. Laptev Sea Ice Thickness maxima shift from 1 to 1.21.3 to 1.4 m from January to February to March. Whereas over Beaufort, the peak of Sea Ice Thickness shifts from 1.2 to 1.5 to 1.7 m from January to February to March. This means the variability in Beaufort is higher than that in Laptev. The method discussed in this paper presents a unique idea of using the Sea Ice Thickness variable over Sea Ice Area and Concentration, especially during winter months, for a better understanding of the sea ice growth. The information obtained using these sea ice parameters would be further utilized by modelers, navigators, etc., which in turn helps improve, forecast studies.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1175/JCLI-D-15-0391.1", "year": 2016, "title": "Has Arctic sea ice loss contributed to increased surface melting of the Greenland ice sheet?", "abstract": "Abstract In recent decades, the Greenland ice sheet has experienced increased surface melt. However, the underlying cause of this increased surface melting and how it relates to cryospheric changes across the Arctic remain unclear. Here it is shown that an important contributing factor is the decreasing Arctic sea ice. Reduced summer sea ice favors stronger and more frequent occurrences of blocking-high pressure events over Greenland. Blocking highs enhance the transport of warm, moist air over Greenland, which increases downwelling infrared radiation, contributes to increased extreme heat events, and accounts for the majority of the observed warming trends. These findings are supported by analyses of observations and reanalysis data, as well as by independent atmospheric model simulations using a state-of-the-art atmospheric model that is forced by varying only the sea ice conditions. Reduced sea ice conditions in the model favor more extensive Greenland surface melting. The authors find a positive feedback between the variability in the extent of summer Arctic sea ice and melt area of the summer Greenland ice sheet, which affects the Greenland ice sheet mass balance. This linkage may improve the projections of changes in the global sea level and thermohaline circulation.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-16-1349-2022", "year": 2022, "title": "Mass evolution of the Antarctic Peninsula over the last 2 decades from a joint Bayesian inversion", "abstract": "Abstract. The Antarctic Peninsula has become an increasingly important component of the Antarctic Ice Sheet mass budget over the last 2 decades, with mass losses generally increasing. However, due to the challenges presented by the topography and geometry of the region, there remain large variations in mass balance estimates from conventional approaches and in assessing the relative contribution of individual ice sheet processes. Here, we use a regionally optimized Bayesian hierarchical model joint inversion approach that combines data from multiple altimetry studies (ENVISAT, ICESat, CryoSat-2 swath), gravimetry (GRACE and GRACE-FO), and localized DEM differencing observations to solve for annual mass trends and their attribution to individual driving processes for the period 20032019. This is first time that such localized observations have been assimilated directly to estimate mass balance as part of a wider-scale regional assessment. The region experienced a mass imbalance rate of -191.1 Gt yr1 between 2003 and 2019, predominantly driven by accelerations in ice dynamic mass losses in the first decade and sustained thereafter. Inter-annual variability is driven by surface processes, particularly in 2016 due to increased precipitation driven by an extreme El Nino, which temporarily returned the sector back to a state of positive mass balance. In the West Palmer Land and the English Coast regions, surface processes are a greater contributor to mass loss than ice dynamics in the early part of the 2010s. Our results show good agreement with conventional and other combination approaches, improving confidence in the robustness of mass trend estimates, and in turn, understanding of the region's response to changes in external forcing.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2017JF004349", "year": 2018, "title": "A Full-Stokes 3-D Calving Model Applied to a Large Greenlandic Glacier", "abstract": "Iceberg calving accounts for around half of all mass loss from both the Greenland and Antarctic ice sheets. The diverse nature of calving and its complex links to both internal dynamics and climate make it challenging to incorporate into models of glaciers and ice sheets. Here we present results from a new open-source 3-D full-Stokes calving model developed in Elmer/Ice. The calving model implements the crevasse depth criterion, which states that calving occurs when surface and basal crevasses penetrate the full thickness of the glacier. The model also implements a new 3-D rediscretization approach and a time-evolution scheme which allow the calving front to evolve realistically through time. We test the model in an application to Store Glacier, one of the largest outlet glaciers in West Greenland, and find that it realistically simulates the seasonal advance and retreat when two principal environmental forcings are applied. These forcings are (1) submarine melting in distributed and concentrated forms and (2) ice m\u00e9lange buttressing. We find that ice m\u00e9lange buttressing is primarily responsible for Store Glacier's seasonal advance and retreat. Distributed submarine melting prevents the glacier from forming a permanent floating tongue, while concentrated plume melting has a disproportionately large and potentially destabilizing effect on the calving front position. Our results also highlight the importance of basal topography, which exerts a strong control on calving, explaining why Store Glacier has remained stable during a period when neighboring glaciers have undergone prolonged interannual retreat.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1002/JOC.6080", "year": 2019, "title": "Backward and forward drift trajectories of sea ice in the northwestern", "abstract": "To track sea ice motion, four ice\u2011tethered buoys were deployed at 84.6\u00b0N and 144.3\u00b0W, 87.3\u00b0N and 172.3\u00b0W, 81.1\u00b0N and 157.4\u00b0W, and 82.8\u00b0N and 166.5\u00b0W in summers of 2008, 2010, 2014, and 2016, respectively. In addition, the remote sensed ice motion product provided by National Snow and Ice Data Center was used to reconstruct backward and forward ice drifting trajectories from the buoy deployment sites during 1979\u20132016. Sea ice in the central Arctic Ocean in late summer is trending to have travelled from lower latitudes, and to be advected to the region more involved in the Transpolar Drift Stream (TDS) during 1979\u20132016. The strengthened TDS has played a crucial role in Arctic sea ice loss from a dynamic perspective. The trajectory of ice is found to be significantly related to atmosphere circulation indices. The Central Arctic Index (CAI), defined as the difference in sea level pressure between 84\u00b0N, 90\u00b0W and 84\u00b0N, 90\u00b0E, can explain 34\u201340% of the meridional displacement along the backward trajectories, and it can explain 27\u201340% of the zonal displacement along the forward trajectories. The winter Beaufort High (BH) anomaly can explain 18\u201327% of the zonal displacement. Under high positive CAI values or high negative winter BH anomalies, floes from the central Arctic tended to be advected out of the Arctic Ocean through Fram Strait or other marginal gateways. Conversely, under high negative CAI values or high positive winter BH anomalies, ice tended to become trapped within a region close to the North Pole or it drifted into the Beaufort Gyre region. The long\u2011term trend and spatial change in Arctic surface air temperature were more remarkable during the freezing season than the melt season because most energy from the lower troposphere is used to melt sea ice and warm the upper ocean during summer.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1017/JOG.2020.98", "year": 2021, "title": "Spatiotemporal variability of surface velocities of monsoon temperate glaciers in the Kangri Karpo Mountains, southeastern Tibetan Plateau", "abstract": "Influenced by the Indian monsoon, the Kangri Karpo Mountains (KKM) of the southeastern Tibetan Plateau is the most humid part of the plateau, and one of the most important regions with numerous monsoon temperate glaciers. Glacier mass balance estimates have been strongly negative in the KKM over recent decades, but the spatiotemporal characteristics of surface velocity are poorly understood. Using phase-correlation feature tracking on Landsat images, this study estimates spatiotemporal variabilities of monsoon temperate glaciers for the period of 19882019. Results show that a significant slowdown was observed below an elevation of 4900 m, while an accelerated ice flow was found at an elevation of 49005800 m over the past 30 years. The trend of slowdown was 0.1 m a1 dec1 during 19882000, and then it increased to 0.5 m a1 dec1 during 20012019.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/TC-15-2623-2021", "year": 2021, "title": "Surface melting over the Greenland ice sheet derived from enhanced resolution passive microwave brightness temperatures (1979\u20132019)", "abstract": "Abstract. Surface melting is a major component of the Greenland ice sheet surface mass balance, and it affects sea level rise through direct runoff and the modulation of ice dynamics and hydrological processes, supraglacially, englacially and subglacially. Passive microwave (PMW) brightness temperature observations are of paramount importance in studying the spatial and temporal evolution of surface melting due to their long temporal coverage (1979present) and high temporal resolution (daily). However, a major limitation of PMW datasets has been the relatively coarse spatial resolution, which has historically been of the order of tens of kilometers. Here, we use a newly released PMW dataset (37 GHz, horizontal polarization) made available through a NASA Making Earth System Data Records for Use in Research Environments (MeASUREs) program to study the spatiotemporal evolution of surface melting over the Greenland ice sheet at an enhanced spatial resolution of 3.125 km. We assess the outputs of different detection algorithms using data collected by automatic weather stations (AWSs) and the outputs of the Modele Atmospherique Regional (MAR) regional climate model. We found that sporadic melting is well captured using a dynamic algorithm based on the outputs of the Microwave Emission Model of Layered Snowpack (MEMLS), whereas a fixed threshold of 245 K is capable of detecting persistent melt. Our results indicate that, during the reference period from 1979 to 2019 (from 1988 to 2019), surface melting over the ice sheet increased in terms of both duration, up to 4.5 (2.9) d per decade, and extension, up to 6.9 % (3.6 %) of the entire ice sheet surface extent per decade, according to the MEMLS algorithm. Furthermore, the melting season started up to 4.0 (2.5) d earlier and ended 7.0 (3.9) d later per decade. We also explored the information content of the enhanced-resolution dataset with respect to the one at 25 km and MAR outputs using a semi-variogram approach. We found that the enhanced product is more sensitive to local-scale processes, thereby confirming the potential of this new enhanced product for monitoring surface melting over Greenland at a higher spatial resolution than the historical products and for monitoring its impact on sea level rise. This offers the opportunity to improve our understanding of the processes driving melting, to validate modeled melt extent at high resolution and, potentially, to assimilate these data in climate models.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1038/S43247-021-00197-5", "year": 2021, "title": "Accelerated sea ice loss in the Wandel Sea points to a change in the Arctic's Last Ice Area", "abstract": "The Arctic Oceans Wandel Sea is the easternmost sector of the Last Ice Area, where thick, old sea ice is expected to endure longer than elsewhere. Nevertheless, in August 2020 the area experienced record-low sea ice concentration. Here we use satellite data and sea ice model experiments to determine what caused this record sea ice minimum. In our simulations there was a multi-year sea-ice thinning trend due to climate change. Natural climate variability expressed as wind-forced ice advection and subsequent melt added to this trend. In spring 2020, the Wandel Sea had a mixture of both thin andunusual for recent yearsthick ice, but this thick ice was not sufficiently widespread to prevent the summer sea ice concentration minimum. With continued thinning, more frequent low summer sea ice events are expected. We suggest that the Last Ice Area, an important refuge for ice-dependent species, is less resilient to warming than previously thought.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1134/S0001433818090219", "year": 2018, "title": "Comparison of Variations in Concentration of Arctic Marine Ice and Duration of Snow Period of Northern Eurasia under Conditions of Present-Day Climate According \u2026", "abstract": "The short period variability of the duration of the occurrence of stable snow cover and the concentration of marine ice is revealed and compared for Northern Eurasia and the adjacent area of the Arctic Ocean against a background of multiannual variations in indices of atmospheric correlation in 20002015. The main principles of multiannual variations in the characteristics are determined. No correlation between the multiannual tendencies and interannual variability is found. Nonetheless, the calculation of the Fourier harmonics allowed identification of three five-year periods similar for all characteristics: 20002004, 20052009, and 20102014. The most intense variations of the duration of the occurrence of stable snow cover and concentration of marine ice from one five-year period to another are typical of the East European Platform in contrast to the noticeable but small variations for Siberia.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/RS12030382", "year": 2020, "title": "Assessing the performance of methods for monitoring ice phenology of the world's largest high Arctic lake using high-density time series analysis of Sentinel-1 data", "abstract": "Lake ice is a dominant component of Canadas landscape and can act as an indicator for how freshwater aquatic ecosystems are changing with warming climates. While lake ice monitoring through government networks has decreased in the last three decades, the increased availability of remote sensing images can help to provide consistent spatial and temporal coverage for areas with annual ice cover. Synthetic aperture radar (SAR) data are commonly used for lake ice monitoring, due to the acquisition of images in any condition (time of day or weather). Using Sentinel-1 A/B images, a high-density time series of SAR images was developed for Lake Hazen in Nunavut, Canada, from 20152018. These images were used to test two different methods of monitoring lake ice phenology: one method using the first difference between SAR images and another that applies the Otsu segmentation method. Ice phenology dates determined from the two methods were compared with visual interpretation of the Sentinel-1 images. Mean errors for the pixel comparison of the first difference method ranged 310 days for ice-on and ice-off, while average error values for the Otsu method ranged 210 days. Mean errors for comparisons of different sections of the lake ranged 015 days for the first difference method and 217 days for the Otsu method. This research demonstrates the value of temporally consistent image acquisition for improving the accuracy of lake ice monitoring.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1017/JOG.2019.15", "year": 2019, "title": "Loss of floating glacier tongues from the Yelverton Bay region, Ellesmere Island, Canada", "abstract": "A total of eight floating glacier tongues have shrunk in area by >85% from the Yelverton Bay region of Northern Ellesmere Island since 1959, with unusually large losses since 2005. To better understand the causes of these losses, this study undertakes the first examination of ice tongue changes in this region, including an assessment of changes in surrounding marine ice (i.e. sea ice, sikussak and melange), and atmospheric and oceanographic forcings. From 1959 to 2017, the total ice tongue area decreased by 49.07 km2, with the majority of this loss occurring from 2005 to 2009 (34.68 km2). The loss of ice tongues since 2005 occurred when open water replaced multi-year landfast sea ice (MLSI) and first-year sea ice in the regions adjacent to the ice tongues. These changes were accompanied by an increase in mean annual mid-depth (i.e. 100 and 200 m) ocean temperatures from 0.29C from 1999 to 2005 to 0.67C from 2006 to 2012. Despite the recent return of ocean temperatures to below pre-2006 levels, atmospheric summer temperatures have continued to rise (+0.15C decade1 between 1948 and 2016), with open water continuing to occur. Without the sustained presence of MLSI in this region the ice tongues are unable to stabilize, making it unlikely that they will re-form in the current climate.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.3390/F10050447", "year": 2019, "title": "Impact of Shortened Winter Road Access on Costs of Forest Operations", "abstract": "A significant portion of the forest harvesting in the cooler regions of North America occurs in the winter when the ground is frozen and can support machine traffic. Climate change may influence the cost of forestry operations by reducing the period of winter access in those cold regions. In this study, we examined the impact of a shortened period of frozen ground conditions on logging operation and costs. To adapt to shorter period of frozen soil conditions, logging contractors might need to provide more machines and labor to complete logging in a shorter period of frozen conditions. The objectives were to calculate the costs of logging operations of a hypothetical forestry company in Alberta, Canada under two conditions: first, when the wood was hauled to the mill directly; and second, when part of the wood was hauled to satellite yards close to the logging area, thereby minimizing the annual number of idle hauling trucks. General Circulation Models were used to predict future winter weather conditions. Using the current type of harvesting machines and hauling directly to the mill, the unit cost of logging operations ($/m3) was projected to increase by an average of 1.6% to 2.5% in 2030s, 2.8% to 5.3% in the 2050s and 4.8% to 10.9% in the 2080s compared to the base year of 20152016. With use of satellite yards during the winter logging, the total logging cost will increase over direct haul, by 1.8% to 2.8% in the 2030s, 3.1% to 5.7% in the 2050s and 5.2% to 11.4% in the 2080s. Using satellite yards, however, will provide year-around employment for hauling truckers and more consistent and reliable hauling operations.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/ISPRS-ARCHIVES-XLIII-B3-2020-925-2020", "year": 2020, "title": "Parameter estimation and motion tracking of pack ice from FY-3/MERSI images", "abstract": "Abstract. A method to estimate the shape parameters and track the motion velocity of pack ice is presented. The method consists of sea ice recognition, pack ice extraction, parameters estimation and motion tracking. We try to estimate the shape parameters and track the motion velocity from FY-3/MERSI images of Fram strait, which were covered by cloud less than 30%. It found that the pack ice concentration significantly decreases faster than sea ice concentration. The two parameters indicate the distribution difference between sea ices and pack ices. The change of the perimeter and mean clamp diameter are obvious owing to they were sensitive to the edge of the pack ices. But the small change of roundness, convexity and width-height ratio indicate the shape similarity of pack ices in various size. More than 80% of the pack ices in the study region are tracked successfully by the proposed method. The resulting motion vectors in the overlapping zones are found to match well with the polar daily grid sea ice motion vectors provided by the National Snow and Ice Data Centre. The method can provide the actual motion vector of pack ices to improve the distribution and details of the grid-to-grid motion vectors.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1175/JCLI-D-21-0129.1", "year": 2022, "title": "Does the recent revival of Western Disturbances govern the Karakoram Anomaly?", "abstract": "Abstract The global retreat in glaciers is considered to be one of the critical indicators of climate change. However, the glaciers of the Karakoram (KR) region of the KarakoramHimalayas (KH) stand out because of their divergent response, displaying a surge as opposed to glaciers in other regions. This phenomenon is known as the Karakoram anomaly. Although many factors control the establishment and sustenance of the anomaly, the present study establishes winter precipitation associated with western disturbances (WDs) over the KH as one of the key drivers behind its emergence. To examine the role of WDs, a tracking algorithm is applied to 39 seasons (NovemberMarch) for three separate (ERA5, MERRA-2, and NCEP-CFSR/CFSv2) reanalysis datasets. The associated reanalysis ensemble statistics of WD properties produced in terms of their intensity, precipitation/snowfall volumes, and wind speed suggest a revival in recent years over the core-anomaly regions. However, the frequency has remained steady. The Karakoram has witnessed a rise of 10% in precipitation intensity associated with WDs in recent decades. The high percentage of snowfall received by the Karakoram (65%) from WDs relative to the total seasonal snowfall suggests a crucial role in modulating the regional mass-balance anomaly. Simultaneously, the amount of snowfall from non-WD sources in the Karakoram has had a statistically significant decline of 17% in recent decades, coinciding with the anomaly period. The enhanced intensity of WDs is found to be associated with changes in increased baroclinic instability and a shift of the subtropical westerly jet mean latitudinal position.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.5194/BG-11-365-2014", "year": 2014, "title": "Calcium carbonate corrosivity in an Alaskan inland sea", "abstract": "Abstract. Ocean acidification is the hydrogen ion increase caused by the oceanic uptake of anthropogenic CO2, and is a focal point in marine biogeochemistry, in part, because this chemical reaction reduces calcium carbonate (CaCO3) saturation states () to levels that are corrosive (i.e., 1) to shell-forming marine organisms. However, other processes can drive CaCO3 corrosivity; specifically, the addition of tidewater glacial melt. Carbonate system data collected in May and September from 2009 through 2012 in Prince William Sound (PWS), a semienclosed inland sea located on the south-central coast of Alaska and ringed with fjords containing tidewater glaciers, reveal the unique impact of glacial melt on CaCO3 corrosivity. Initial limited sampling was expanded in September 2011 to span large portions of the western and central sound, and included two fjords proximal to tidewater glaciers: Icy Bay and Columbia Bay. The observed conditions in these fjords affected CaCO3 corrosivity in the upper water column (< 50 m) in PWS in two ways: (1) as spring-time formation sites of mode water with near-corrosive levels seen below the mixed layer over a portion of the sound, and (2) as point sources for surface plumes of glacial melt with corrosive levels ( for aragonite and calcite down to 0.60 and 1.02, respectively) and carbon dioxide partial pressures (pCO2) well below atmospheric levels. CaCO3 corrosivity in glacial melt plumes is poorly reflected by pCO2 or pHT, indicating that either one of these carbonate parameters alone would fail to track in PWS. The unique and pCO2 conditions in the glacial melt plumes enhances atmospheric CO2 uptake, which, if not offset by mixing or primary productivity, would rapidly exacerbate CaCO3 corrosivity in a positive feedback. The cumulative effects of glacial melt and airsea gas exchange are likely responsible for the seasonal reduction of in PWS, making PWS highly sensitive to increasing atmospheric CO2 and amplified CaCO3 corrosivity.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.COLDREGIONS.2016.06.006", "year": 2016, "title": "Photogrammetric retrieval and analysis of small scale sea ice topography during summer melt", "abstract": "The paper presents a setup for photogrammetric retrievals of small scale sea ice surface topography using low-altitude aerial imagery. The setup features two digital cameras, a combined GPS receiver/inertial navigation system (INS) unit, and a laser range finder. The components are fit in a single aerodynamic enclosure mounted outside a helicopter cabin. Results from its first deployment during the field campaign on Arctic sea ice north of Svalbard during summer 2012 are shown. Comparison of photogrammetrically derived digital elevation models (DEMs) with in situ measurements of sea ice topography made on melting first year sea ice demonstrated the ability of the method to accurately recover the topography of sea ice including melt ponds with depths down to at least 0.3m. The inter-comparison of the photogrammetrically derived DEM and in situ measured elevations yielded estimates of a root mean square error (RMS) of about 0.04m and bias of 0.03m, both for sea ice freeboard and melt pond depths. The bimodality of the probability density function of measured melt pond depths was also accurately reproduced in the reconstructed DEM. Discrepancies between the measured and DEM distributions were within the range of the inferred uncertainty of the photogrammetric and in situ techniques, with some of the bias likely associated with sea ice melt during the time elapsed between in situ and aerial measurements.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2019JD031914", "year": 2020, "title": "Multiscale Changes in Snow Over the Tibetan Plateau During 1980-2018", "abstract": "The Tibetan Plateau has experienced substantial warming during the last few decades. As a result, the cryosphere of the Tibetan Plateau, including the snow cover, has shown significant changes. We characterized the changes in snow over the Tibetan Plateau using several snow-related indices, including snow depth and snow-covered days based on the MERRA-2 and JRA-55 reanalysis data set and passive microwave (MW) satellite observations. The analyses were performed over different time periods\u2014including the last 38, 30, 20, and 10 snow seasons\u2014from 1980 to 2018. The results show that the significant trends in snow depth and snow-covered days are dependent on both the season and region and vary with the data set and snow-related index used. There was a clear decrease in the annual maximum consecutive snow-covered days (CSCDMax), and this was characterized by a later begin time and an earlier end time for both MERRA-2 and JRA-55, but only a later begin time for MW during the time period 1980-2018. The changes in CSCDMax were generally dominated by changes in the begin time, which were mainly caused by the increase in the average 2-m air temperature for November-December. The relatively weak trends in the end time were a result of the combined impact of warmer temperatures and more precipitation in March-April. The CSCDMax averaged over the Tibetan Plateau showed decreasing trends in all studied time periods for JRA-55 and MW and in the last 38 and 10 snow seasons for MERRA-2 during the time period 1980-2018.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1029/2020JG005795", "year": 2020, "title": "Carbon Dioxide Production in Bedrock Beneath Soils Substantially Contributes to Forest Carbon Cycling", "abstract": "Soils are widely considered the primary terrestrial organic matter pool mediating carbon transactions with the atmosphere and groundwater. Because soils are both a host and a product of rhizosphere activity, they are thought to mark the location where photosynthetic fixation of carbon dioxide (CO2) is balanced by the oxidation of organic matter. However, in many terrestrial environments, the rhizosphere extends below soils and into fractured bedrock, and it is unknown if the resulting biological and hydrologic dynamics in bedrock have a significant impact on carbon cycling. Here we show substantial production of CO2 in weathered bedrock at 4-8 m below the thin soils (<0.5 m thick) of a Northern California forest using innovative monitoring technology for sampling gases and water in fractured rock. The deep CO2 production supports a persistent upward flux of CO2(g) year-round from bedrock to soil, constituting between 2% and 29% of the average daily CO2 efflux from the land surface. When water is rapidly transported across the fractured bedrock vadose zone, nearly 50% of the CO2 produced in the bedrock dissolves into water, promoting water-rock interaction and export of dissolved inorganic carbon (DIC) from the unsaturated zone to groundwater, constituting as much as 80% of the DIC exiting the hillslope. Such CO2 production in weathered bedrock is subject to unique moisture, temperature, biological, and mineralogical conditions which are currently missing from terrestrial carbon models.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/CP-17-21-2021", "year": 2021, "title": "PMIP4/CMIP6 last interglacial simulations using three different versions of MIROC: importance of vegetation", "abstract": "Abstract. We carry out three sets of last interglacial (LIG) experiments, named lig127k, and of pre-industrial experiments, named piControl, both as part of PMIP4/CMIP6 using three versions of the MIROC model: MIROC4m, MIROC4m-LPJ, and MIROC-ES2L. The results are compared with reconstructions from climate proxy data. All models show summer warming over northern high-latitude land, reflecting the differences between the distributions of the LIG and present-day solar irradiance. Globally averaged temperature changes are 0.94 K (MIROC4m), 0.39 K (MIROC4m-LPJ), and 0.43 K (MIROC-ES2L). Only MIROC4m-LPJ, which includes dynamical vegetation feedback from the change in vegetation distribution, shows annual mean warming signals at northern high latitudes, as indicated by proxy data. In contrast, the latest Earth system model (ESM) of MIROC, MIROC-ES2L, which considers only a partial vegetation effect through the leaf area index, shows no change or even annual cooling over large parts of the Northern Hemisphere. Results from the series of experiments show that the inclusion of full vegetation feedback is necessary for the reproduction of the strong annual warming over land at northern high latitudes. The LIG experimental results show that the warming predicted by models is still underestimated, even with dynamical vegetation, compared to reconstructions from proxy data, suggesting that further investigation and improvement to the climate feedback mechanism are needed.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ENVDEV.2019.100464", "year": 2019, "title": "Vegetation dynamics and ecosystem service values changes at national and", "abstract": "Identification of vegetation changes and economic valuation of natural resources are important to strengthen national economy and sustainable environment development. This study identified the changes in vegetation and ecosystem service values at the national and provincial scales in Nepal from 2000 to 2017. Mann Kendall test statistics and Sen's slope were computed for temporal and spatial normalized difference vegetation index (NDVI) values in each pixel having a spatial resolution of 250 m and at 16-days interval. Land cover types were defined based on the NDVI values and applied ecosystem service values (ESV) coefficient. Results show that NDVI has significantly increased in Nepal with an average trend of 0.0018 yr-1 during 2000-2017. Except for Province 6, the NDVI has increased significantly in all the provinces. Results additionally suggested a 27.88% greening in Nepal. At the provincial scale, the highest (56.41%) and lowest (12.52%) greening were observed in Provinces 2 and 6, respectively. In 2017, the total ESV in Nepal was 21.88 billion USD which showed a 1.15 billion USD higher than in year 2000. The ESV has increased in forests but decreased in the croplands, grasslands and barren lands between 2000 and 2017. The ESV of national forest are estimated at 19.17 billion USD in 2017. The highest value of 4.17 billion USD and the lowest of 1.09 billion USD were found in Provinces 1 and 2, respectively. Meanwhile, the available ESV per capita was relatively higher in Province 6 and lower in the Province 2. As the ESV is important lifeline for the society, this study provides crucial information about how this important environmental parameter has changed over time in Nepal.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS13183756", "year": 2021, "title": "Global change in terrestrial ecosystem detected by fusion of microwave and optical satellite observations", "abstract": "The detection of global land change via satellite observation is a major challenge in improving the understanding of global environmental change. In this study, we develop a new vegetation index which can be used as a proxy for the fractions of tree canopy and short vegetation, based on the simple linear regression between microwave vegetation optical depth (VOD) and optical leaf area index (LAI). Although we use no high-resolution reference data, the newly developed vegetation index successfully detects global land change which has been reported by previous estimations based on high-resolution reference data. We find that the relationship between VOD and LAI is non-stationary and the temporal change in the VOD-LAI relationship is an important signal for detecting global change in the terrestrial ecosystem.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/JOC.7367", "year": 2022, "title": "On the sensitivity of the Amazon surface climate to two land\u2010surface hydrology schemes using a high\u2010resolution regional climate model (RegCM4)", "abstract": "Two 11-year simulations were conducted to investigate the influence of two runoff schemes in the community land model version 4.5 (CLM45) on the Amazon surface energy balance and surface climate using a high-resolution regional climate model (RegCM4-CLM45). The default scheme is TOPMODEL (TOP), while the alternative is Variable Infiltration Capacity (VIC). In the two simulations, the vegetation status is prescribed (satellite phenology; SP). The first simulation was designated as SP-TOP, while the second simulation was referred to as SP-VIC, and both of them were evaluated using reanalysis products (e.g., ERA5) and micrometeorology data measurements. Results show that the SP-VIC severely underestimates latent heat and overestimates sensible heat fluxes, more than SP-TOP in comparison with the ERA5. This explains the large warm bias observed in the winter season. On the other hand, the SP-VIC shows a slightly smaller dry bias than SP-TOP against the Climate Research Unit (CRU) data. Our results show that SP-VIC does not improve the quality of the simulation compared to SP-TOP, which suggests the necessity of additional calibration of the VIC surface parameters using in situ observations of the Amazon and revising the VIC runoff scheme to perform new sensitivity experiments. The same needs to be done with SP-TOP.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1111/GCB.15864", "year": 2021, "title": "Mapping soil microbial residence time at the global scale", "abstract": "AbstractSoil microbes are the fundamental engine for carbon (C) cycling. Microbial residence time (MRT) therefore determines the mineralization of soil organic C, releasing C as heterotrophic respiration and contributing substantially to the C efflux in terrestrial ecosystems. We took use of a comprehensive dataset (2627 data points) and calculated the MRT based on the basal respiration and microbial biomass C. Large variations in MRT were found among biomes, with the largest MRT in boreal forests and grasslands and smallest in natural wetlands. Biogeographic patterns of MRT were found along climate variables (temperature and precipitation), vegetation variables (root C density and net primary productivity), and edaphic factors (soil texture, pH, topsoil porosity, soil C, and total nitrogen). Among environmental factors, edaphic properties dominate the MRT variations. We further mapped the MRT at the global scale with an empirical model. The simulated and observed MRT were highly consistent at plot (R2= .86), site (R2 = .88), and biome (R2 = .99) levels. The global average of MRT was estimated to be 38 (5) days. A clear latitudinal biogeographic pattern was found for MRT with lower values in tropical regions and higher values in the Arctic. The biome and globallevel estimates of MRT serve as valuable data for parameterizing and benchmarking microbial models.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/W14111792", "year": 2022, "title": "Downscaling Microwave Soil Moisture Products with SM-RDNet for Semiarid Mining Areas", "abstract": "Surface soil moisture (SM), as a crucial ecological element, is significant to monitor in semiarid mining areas characterized by aridity and little rainfall. The passive microwave remote sensing, which is not affected by weather, provides more accurate SM information, but the resolution is too coarse for mining areas. The existing downscaling method is usually pointed to natural scenarios like agricultural fields rather than mining areas with high-intensity mining. In this paper, combined with geoinformation related to SM, we designed a convolutional neural network (SM-Residual Dense Net, SM-RDNet) to downscale SMAP/Sentinel-1 Level-2 radiometer/radar soil moisture data (SPL2SMAP_S SM) into 10 m spatial resolution. Based on the in-site measured data, the root mean square error (RMSE) was utilized to verify the downscaling accuracy of SM-RDNet. In addition, we analyzed its performance for different data combinations, vegetation cover types and the advantages compared with random forest (RF). Experimental results show that: (1) The downscaling from the 3 km product with the combination of auxiliary data NDVI + DEM + slope performs best (RMSE 0.0366 m3/m3); (2) Effective data combinations can improve the downscaling accuracy at the range of 0.04770.1176 m3/m3 (RMSE); (3) The SM-RDNet shows better spatial completeness, details and accuracy than RF (RMSE improved by 0.0905 m3/m3). The proposed SM-RDNet can effectively obtain the fine-grained SM in semiarid mining areas. Our method bridges the gap between coarse-resolution microwave SM products and ecological applications of small-scale mining areas, and provides data and technical support for future research to explore how the mining effect SM in semiarid mining areas.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2019WR026038", "year": 2020, "title": "An Improved Optimization Scheme for Representing Hillslopes and", "abstract": "Understanding hydrological processes is essential for management of water resources and for promoting catchment sustainability. In karst regions, landscapes are spatially heterogeneous and include discontinuous soil distribution, and complex networks of matrices and conduits in hillslopes and depressions, which result in variation in hydrological processes. However, most previous studies have mainly focused on the effects of the distribution of soil depth and the fast-slow flow in the matrices and conduits on hydrological processes and ignored the different hydrological processes related to hillslopes and depressions. This study improved the VarKarst model by adding randomly distributed soil and epikarst depths (RSE), fast-slow flow (FS), and hillslopes and depressions (HD). The improved model was calibrated and validated in six large catchments (1,213-5,454 km2) and one small catchment (1.25 km2). Results showed that the schemes by combining FS and HD (Scenario FS + HD) and combining RSE, FS, and HD (Scenario RSE + FS + HD) improved model performance (calibrated and validated KGE ranged from 0.54 to 0.89 and AIC ranged from -336.49 to 669.77) compared models that included other schemes (original VarKarst, Scenario RSE, Scenario FS, Scenario HD, and Scenario RSE + FS), especially when reproducing discharge of peaks and recessions. These results suggest that there is a need to separate the hillslopes and depressions when modeling karstic hydrological processes.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1109/IGARSS46834.2022.9884432", "year": 2022, "title": "Progress in Time-Series Soil Moisture Retrieval Using L-and S-Band Radar Backscatter", "abstract": "L- and S-band observations from NASA's Passive/Active L/S band (PALS) sensor from the SMEX02 campaign were used to estimate soil moisture. The retrieval process is based on the alpha approximation method. This method utilizes a time-series of normalized radar backscatter measurements as well as ancillary information to estimate soil moisture over the Walnut Creek watershed. The resulting retrieved soil moistures are compared to in-situ soil moisture measurements at multiple test sites within the watershed. The calculations show reasonable results for both L- and S-band and provide further insight into the use of L- and S-bands for the upcoming NASA/ISRO mission.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS14174203", "year": 2022, "title": "Quantifying the Influences of Driving Factors on Vegetation EVI Changes Using Structural Equation Model: A Case Study in Anhui Province, China", "abstract": "Vegetation cover is important to the stability of regional ecosystems and is a focus of research on the relationship between natural and human environments. Although some studies have investigated the association between changes in vegetation cover and various influencing factors, these have shortcomings in quantifying direct and indirect effects. In this study, MOD13Q1 enhanced vegetation index (EVI) data for Anhui Province, China, were acquired between 2000 and 2020. The univariate linear regression, coefficient of variation and Hurst index methods were used to analyze spatial and temporal trends and fluctuations in the EVI between 2000 and 2020 and predict future trends. The impact of land-use change on EVI change was explored using 2000 and 2020 land-use data. Finally, a structural equation model (SEM) was used to quantify the effects of topography, annual average temperature, annual precipitation and human activity changes on EVI variation in Anhui Province. The results show that (1) from 2000 to 2020, the overall EVI in Anhui Province showed a fluctuating trend that increased at a rate of 0.018110a1, and 67.1% of the study area showed a greening trend. The EVI was relatively stable in most regions, with regions of fluctuating EVI being mostly affected by urbanization. For a period after 2020, the overall EVI change will exhibit anti-sustainability and will likely decrease. (2) Among the regions of EVI increase, 72.2% had no change in land-use type, while 10.8% and 6.6% changed to farmland and woodland land uses, respectively. Among the regions where EVI decreased, 69.9% had no change in land-use type, while 13.7% changed from farmland to construction land. (3) Overall, human activity change was the main influence on EVI change, which was mainly reflected in the negative impacts of accelerated urbanization. Topography had direct and indirect effects on EVI variations in Central and Southern Anhui. Annual precipitation change had a stronger impact on EVI variation in Northern and Central Anhui than in Southern Anhui, while annual average temperature change had a small impact in the entire province. Compared with other study methods, SEM provides a new approach to quantifying the influences of vegetation cover dynamics. In addition, the results of this study have important implications for ecological environmental protection and sustainable development in Anhui Province.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.GLOPLACHA.2020.103225", "year": 2020, "title": "Contribution of vegetation change to the surface radiation budget: A satellite perspective", "abstract": "The surface radiation budget is of crucial importance to ecosystem evolution but varies with complex atmospheric and surface conditions. Vegetation change alters the surface thermal properties and the subsequent radiation budget; however, the vegetation contribution is difficult to isolate from mixed influences. Based on satellite observations, we apply a novel trajectory-based approach to detect the impact of vegetation change on the global surface radiation variation in recent decades (20012016). Satellite data on radiation and vegetation available from the Clouds and the Earth's Radiant Energy System (CERES) and Moderate Resolution Imaging Spectroradiometer (MODIS) instruments are adopted for this investigation. Methodologically, the surface net radiation (Rn) in the nonchanged vegetation trajectory represents the synthetic result of atmospheric influences and serves as a reference for isolating Rn variations due to vegetation change. The results demonstrate that the multiyear mean of global Rn is 71.57 Wm2 with an increasing trend of 0.053 Wm2yr1. Vegetation change contributes an additional 0.047 Wm2yr1 of radiation in greening regions, accounting for 53.36% of the total increase in Rn. Spatially, the contribution of vegetation presents significant variability, with positive contributions located mainly in western Europe and southern Africa and negative contributions located mainly in parts of Asia and eastern Australia. Physically, the influence of vegetation change on the surface radiation budget originates from its alteration of albedo and emissivity, particularly the former. Specifically, a 1% increase in the normalized difference vegetation index (NDVI) is expected to reduce albedo by 0.003 and increase surface net shortwave radiation by 0.86 Wm2. It can be concluded that the change in albedo by vegetation change has a nonnegligible influence on the surface radiation budget in different regions. These results help capture the physical mechanism responsible for the evolution of Earth's radiation and support environmental management.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.5194/ESSD-11-675-2019", "year": 2019, "title": "A leaf area index data set acquired in Sahelian rangelands of Gourma in Mali over the 2005\u20132017 period", "abstract": "Abstract. The leaf area index of Sahelian rangelands and related variables such as the vegetation cover fraction, the fraction of absorbed photosynthetically active radiation and the clumping index were measured between 2005 and 2017 in the Gourma region of northern Mali. These variables, known as climate essential variables, were derived from the acquisition and the processing of hemispherical photographs taken along 1 km linear sampling transects for five contrasted canopies and one millet field. The same sampling protocol was applied in a seasonally inundated Acacia open forest, along a 0.5 km transect, by taking photographs of the understorey and the tree canopy. These observations collected over more than a decade, in a remote and not very accessible region, provide a relevant and unique data set that can be used for a better understanding of the Sahelian vegetation response to the current rainfall changes. The collected data can also be used for satellite product evaluation and land surface model development and validation. This paper aims to present the field work that was carried out during 13 successive rainy seasons, the measured vegetation variables, and the associated open database. Finally, a few examples of data use are shown. DOI of the referenced data set: https://doi.org/10.17178/AMMA-CATCH.CE.Veg_Gh.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1080/15230430.2019.1650542", "year": 2019, "title": "NDVI\u2013Climate relationships in high-latitude mountains of Alaska and Yukon Territory", "abstract": "High-latitude systems in northwestern Canada and Alaska have warmed rapidly. The aim of this study was to examine how a remotely sensed proxy of vegetation productivity varied among mountain ranges with respect to elevation and climate from 20022017. Our study area included high-latitude mountains in Alaska, USA, and Yukon Territory, Canada, ranging from cold arctic mountains in the tundra biome to warmer interior mountains areas within the boreal biome. We used the annual maximum Normalized Difference Vegetation Index (NDVI) data from the 250-m MODIS NDVI product as a proxy of maximum growing season photosynthetic activity. The long-term (16-year) and interannual pattern of maximum NDVI was investigated with respect to elevation, July temperature, and July precipitation classes within four climatic mountain regions. The July temperature lapse rate was consistently linear, whereas the long-term maximum NDVI lapse rate was nonlinear. At lower elevations, the high-precipitation region had the highest NDVI, whereas the interior mountains region had the highest NDVI at higher elevations. The long-term maximum NDVI was negatively correlated with July precipitation for areas with July temperature below 12C. Above 12C, NDVI was positively correlated with July precipitation, with the greatest rate of NDVI increase with precipitation at the warmest July temperature class. The pattern of interannual peak NDVI with respect to July temperature was not as strong as the long-term pattern; however, the only interannual negative correlation between peak NDVI and July temperature was at lower elevations within the interior mountains. We concluded that among a regional climatic gradient of mountain areas, low growing season temperature and length were likely constraining vegetation productivity, and lower growing season moisture may be an important constraint at the warmest interior mountains region.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.EJRH.2020.100755", "year": 2020, "title": "Trends in streamflow, evapotranspiration, and groundwater storage across the Amazon Basin linked to changing precipitation and land cover", "abstract": "Study region\nThe study region is the Amazon River Basin, which controls globally important water and energy fluxes.\nStudy focus\nIn the face of a changing climate and landscape, it is critical that we understand how, where, and why surface water resources are changing. Specifically, we must consider holistic changes to the water cycle to understand how water resources are affected by climate change and landscape alterations. In this study, we investigate changes to all major components of the water balance across the entire Amazon Basin. We seek to understand: 1) how changes to land cover and precipitation affect streamflow, 2) how these factors affect evapotranspiration and groundwater storage water balance components, and 3) how changes to the water balance partitioning may in turn alter streamflows.\nNew hydrological insights\nWe find significant changes to streamflow of 9.5 mm/yr on average across the Amazon Basin. Streamflow alterations show a spatially variable pattern, with increasing discharge in the northern and western portions of the basin, and decreasing discharge in the southern and eastern basin. We also observe significant changes in evapotranspiration of 29 mm/yr and groundwater storage increases of 7.1 mm/yr. Together, these results indicate that studies of streamflow change in the Amazon should consider changes to the whole water budget, including understudied aspects of groundwater storage across the Basin.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/RS14112638", "year": 2022, "title": "Strain Field Features and Three-Dimensional Crustal Deformations Constrained by Dense GRACE and GPS Measurements in NE Tibet", "abstract": "The continuing impact between the Eurasia Plate and India results in the thickening and shortening of the N-S Tibetan Plateau. There has been strong tectonic movement along the boundary of the zones of deformation of the NE corner of the Tibetan plateau (NET) since the new tectonic period, with its dynamic mechanisms remaining controversial. Here, we use observations of 39 Continuous Global Positioning System (CGPS) gauges and 451 Crustal Movement Observation Network of China (CMONOC) campaign-mode stations to detect the three-dimensional deformation of the crust in the NET. Improved processing procedures are implemented to strengthen the patterns of strain throughout the NET. The principal component analysis (PCA) technique is introduced to decompose the time series into spatial eigenvectors and principal components (PCs), and the first three PCs are used to estimate and rectify common mode errors (CMEs). In addition, GRACE observations are used to detect deformation changes that account for non-tidal oceanic mass loading, hydrological loading, and surface pressure. The rectified deformation of the crust indicates the anisotropic nature of both the subsidence and uplift, and that the highest uplift rate of the Longmen Shan fault uplift reaches 7.13 0.53 mm/yr. Finally, the horizontal velocity is further used to enumerate the strain rates throughout the NET. The results show that the shear band retained property in line with the strike-slip fault along the Altyn Tagh fault, the Qilian Shan faults, the Haiyuan fault, the West Qinling fault, the East Kunlun fault, and the Longmen Shan fault. In addition, the results further indicate that the whole NET shows a strong relationship with the mean principal rates of horizontal shortening strain. Extension and compression of the crust reasonably describe its sinking and uplifting.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3390/W12061726", "year": 2020, "title": "Retrieval of soil moisture by integrating Sentinel-1A and MODIS data over agricultural fields", "abstract": "Soil moisture is an essential variable in the land surface ecosystem, which plays an important role in agricultural drought monitoring, crop status monitoring, and crop yield prediction. High-resolution radar data can be combined with optical remote-sensing data to provide a new approach to estimate high-resolution soil moisture over vegetated areas. In this paper, the Sentinel-1A data and the Moderate Resolution Imaging Spectroradiometer (MODIS) data are combined to retrieve soil moisture over agricultural fields. The advanced integral equation model (AIEM) is utilized to calculate the scattering contribution of the bare soil surface. The water cloud model (WCM) is applied to model the backscattering coefficient of vegetated areas, which use two vegetation parameters to parameterize the scattering and attenuation properties of vegetation. Four different vegetation parameters extracted from MODIS products are combined to predict the scattering contribution of vegetation, including the leaf area index (LAI), the fraction of photosynthetically active radiation (FPAR), normalized difference vegetation index (NDVI), and the enhanced vegetation index (EVI). The effective roughness parameters are chosen to parameterize the AIEM. The Sentinel-1A and MODIS data in 2017 are used to calibrate the coupled model, and the datasets in 2018 are used for soil moisture estimation. The calibration results indicate that the Sentinel-1A backscattering coefficient can be accurately predicted by the coupled model with the Pearson correlation coefficient (R) ranging from 0.58 to 0.81 and a root mean square error (RMSE) ranging from 0.996 to 1.401 dB. The modeled results show that the retrieved soil moisture can capture the seasonal dynamics of soil moisture with R ranging from 0.74 to 0.81. With the different vegetation parameter combinations used for parameterizing the scattering contribution of the canopy, the importance of suitable vegetation parameters for describing the scattering and attenuation properties of vegetation is confirmed. The LAI is recommended to characterize the scattering properties. There is no obvious clue for selecting vegetation descriptors to characterize the attenuation properties of vegetation. These promising results confirm the feasibility and validity of the coupled model for soil moisture retrieval from the Sentinel-1A and MODIS data.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.2478/JOHH-2018-0011", "year": 2018, "title": "Modis Snowline Elevation Changes During Snowmelt Runoff Events in Europe", "abstract": "This study evaluates MODIS snow cover characteristics for large number of snowmelt runoff events in 145 catchments from 9 countries in Europe. The analysis is based on open discharge daily time series from the Global Runoff Data Center database and daily MODIS snow cover data. Runoff events are identified by a base flow separation approach. The MODIS snow cover characteristics are derived from Terra 500 m observations (MOD10A1 dataset, V005) in the period 2000-2015 and include snow cover area, cloud coverage, regional snowline elevation (RSLE) and its changes during the snowmelt runoff events. The snowmelt events are identified by using estimated RSLE changes during a runoff event. The results indicate that in the majority of catchments there are between 3 and 6 snowmelt runoff events per year. The mean duration between the start and peak of snowmelt runoff events is about 3 days and the proportion of snowmelt events in all runoff events tends to increase with the maximum elevation of catchments. Clouds limit the estimation of snow cover area and RSLE, particularly for dates of runoff peaks. In most of the catchments, the median of cloud coverage during runoff peaks is larger than 80%. The mean minimum RSLE, which represents the conditions at the beginning of snowmelt events, is situated approximately at the mean catchment elevation. It means that snowmelt events do not start only during maximum snow cover conditions, but also after this maximum. The mean RSLE during snowmelt peaks is on average 170 m lower than at the start of the snowmelt events, but there is a large regional variability.", "labels": [ { "id": 3, "name": "Cryospheric Indicators" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ECOSER.2018.08.005", "year": 2018, "title": "Uncertainty in data for hydrological ecosystem services modelling: Potential implications for estimating services and beneficiaries for the CAZ Madagascar", "abstract": "This study assesses the differences in modelled total runoff and modelled runoff delivered to people between different rainfall and population datasets in the Ankeniheny Zhamena Corridor (CAZ) of Eastern Madagascar. Runoff is estimated using the WaterWorld hydrological model driven by six rainfall datasets, and population is derived from five population datasets. Model results for runoff under different rainfall datasets lead to variability in runoff (coefficient of variation) up to 99% for single months and 60% in the dry season. These differences are much larger than differences in estimated runoff between baseline and complete deforestation scenario for each rainfall dataset. Population estimates for the CAZ range from 1.2 to 2 million between the population datasets. Differences in runoff under different rainfall datasets lead to an average of 356,000 people estimated to receive 90% more runoff and nearly 750,000 people estimated to receive 50% more or less runoff relative to a baseline rainfall dataset. Therefore, the choice of rainfall data in hydrological ecosystem services modelling has a large influence on estimates of ecosystem service flows highlighting the need for modellers to justify their data choices and report on uncertainties in results, particularly in light of potential policy decisions based on modelled outcomes.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.2136/SSSAJ2013.08.0349NAFSC", "year": 2014, "title": "Regional assessment of soil microbial functional diversity of Douglas\u2010fir forests", "abstract": "Extracellular enzyme activity (EEA) provides a functional fingerprint of soil microbial communities and can be an indicator of change following disturbance. This study examined the EEA of nine managed, Douglasfir [Pseudotsuga menziesii (Mirb.) Franco] dominated forests in the Pacific Northwest of the United States. It assessed the variability of EEA both within and among sites and correlated EEA with environmental variables covered by the broad geographical range of the study sites. This characterization was linked with measures of community size, C and N cycling ability, and other soil properties, such as texture and nutrient status, to provide insights into extracellular enzyme production and microbial function. Principal components analysis and multiple response permutation procedure results indicated that EEA is highly variable among sites but much less variable within sites. It also revealed that the functional fingerprint of the soil tended to be more similar for soils within the same soil order. Additionally, the results implied that phosphatase and the Ccycling enzymes glucosidase and cellobiohydrolase are constitutive in these systems, whereas the Nscavenging enzymes Nacetylglucosaminidase and leucine aminopepdidase are facultative. Furthermore, the Ncycling EEA suggests an N limitation in these sites despite N fertilization. This characterization will be critical in assessing microbial community changes following timber harvest.", "labels": [ { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.ECOENV.2021.113042", "year": 2021, "title": "Urban greenness and survival in lung cancer patients: A registry-based", "abstract": "Background. Previous studies have reported inverse associations between urban greenness and mortality. However, findings regarding contemporaneous and cumulative average greenness exposure are inconsistent. A potential explanation is the weak effects of greenness among the general population. This study assessed the associations between contemporaneous and cumulative average greenness exposure and survival in lung cancer patients.

Methods. An open cohort consisting of lung cancer patients enrolled from 1 January 2001 was studied. The cohort was followed up until 31 December 2018. We evaluated contemporaneous and cumulative greenness exposure using the normalized difference vegetation index (NDVI) within a 250 m buffer of each patient's geocoded residential address. The association between NDVI and mortality was evaluated using both time-fixed and time-varying Cox models. Their difference was compared either.

Results. In time-fixed Cox models, a 0.1-unit increment in contemporaneous and cumulative average NDVI was associated with 17% (95% confidence interval [CI], 15-18%) and 7% (95% CI, 5-8%) reductions in mortality rate, respectively. Time-varying Cox models consistently revealed significant associations, but their magnitudes were lower, at 2% (95% CI, 1-3%) for both contemporaneous and cumulative average NDVI. Compared to the time-fixed models, the time-varying ones exhibited better fit for the proportional hazard assumption in Cox regressions with more conservative results.

Conclusion. Urban greenness is positively associated with an increased chance of survival in lung cancer patients. Compared to time-fixed Cox models, the results of time-varying Cox models were more conservative. This study confirms the beneficial health effects of urban greenness, which may facilitate the improvement of public health by urban green space planning.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/IJERPH192013555", "year": 2022, "title": "Forecasting Weekly Dengue Cases by Integrating Google Earth Engine-Based Risk Predictor Generation and Google Colab-Based Deep Learning Modeling in \u2026", "abstract": "Efficient and accurate dengue risk prediction is an important basis for dengue prevention and control, which faces challenges, such as downloading and processing multi-source data to generate risk predictors and consuming significant time and computational resources to train and validate models locally. In this context, this study proposed a framework for dengue risk prediction by integrating big geospatial data cloud computing based on Google Earth Engine (GEE) platform and artificial intelligence modeling on the Google Colab platform. It enables defining the epidemiological calendar, delineating the predominant area of dengue transmission in cities, generating the data of risk predictors, and defining multi-date ahead prediction scenarios. We implemented the experiments based on weekly dengue cases during 20132020 in the Federal District and Fortaleza, Brazil to evaluate the performance of the proposed framework. Four predictors were considered, including total rainfall (Rsum), mean temperature (Tmean), mean relative humidity (RHmean), and mean normalized difference vegetation index (NDVImean). Three models (i.e., random forest (RF), long-short term memory (LSTM), and LSTM with attention mechanism (LSTM-ATT)), and two modeling scenarios (i.e., modeling with or without dengue cases) were set to implement 1- to 4-week ahead predictions. A total of 24 models were built, and the results showed in general that LSTM and LSTM-ATT models outperformed RF models; modeling could benefit from using historical dengue cases as one of the predictors, and it makes the predicted curve fluctuation more stable compared with that only using climate and environmental factors; attention mechanism could further improve the performance of LSTM models. This study provides implications for future dengue risk prediction in terms of the effectiveness of GEE-based big geospatial data processing for risk predictor generation and Google Colab-based risk modeling and presents the benefits of using historical dengue data as one of the input features and the attention mechanism for LSTM modeling.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.SCITOTENV.2022.154899", "year": 2022, "title": "Health risks of extended exposure to low-level UV radiation\u2013An analysis of ground-based and satellite-derived data", "abstract": "This study aims to indicate the importance of revising current health recommendations concerning the duration of exposure and individual sensitivity of the skin to solar ultraviolet (UV) radiation. For this purpose, a 16-year data series (20052020) of erythemal radiant exposure (Her) and UV index (UVI) for Serbia was analyzed. The UV-related risk was estimated for lighter skin (skin phototypes I-IV) under prolonged exposure on days when maximum UVI was below the recommended protection threshold (UVIlow days, for UVI < 3). Risk assessment was performed for seasonal exposure using satellite-derived data (OMUVBd product) previously validated by ground-based measurements in Novi Sad. The assessment of harmful effects included an analysis of the relation between the daily maximum UVI and the corresponding daily Her, the occurrence of UVIlow days, the exceedance of minimal erythema dose (MED), and the minimum duration of exposure to induce erythema (tMED) for all lighter skin phototypes. It was found that the share of UVIlow days in the total number of days in Serbia increases with the latitude, with the highest percentage in winter (up to 69.454%) and the lowest in summer (up to 3.468%). The results show that the daily Her frequently exceeded the harmful threshold for lighter skin phototypes I-IV (on average by 91.521, 84.923, 70.556, and 56.515%, respectively) on UVIlow days. It was found that prolonged exposure on days with a maximum of UVI = 2 poses a significant risk of erythema for all lighter skin phototypes, even for a duration of 3 h in the middle of the day, as well as medium risk for UVI = 1, and an absence of risk for UVI = 0. The results suggest that health recommendations should be revised, especially in the mid-latitudes, where the share of UVIlow days is large, and in areas where the population is predominantly lighter-skinned.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.7554/ELIFE.19571", "year": 2016, "title": "Global mapping of highly pathogenic avian influenza H5N1 and H5Nx clade 2.3.4.4 viruses with spatial cross-validation", "abstract": "Global disease suitability models are essential tools to inform surveillance systems and enable early detection. We present the first global suitability model of highly pathogenic avian influenza (HPAI) H5N1 and demonstrate that reliable predictions can be obtained at global scale. Best predictions are obtained using spatial predictor variables describing host distributions, rather than land use or eco-climatic spatial predictor variables, with a strong association with domestic duck and extensively raised chicken densities. Our results also support a more systematic use of spatial cross-validation in large-scale disease suitability modelling compared to standard random cross-validation that can lead to unreliable measure of extrapolation accuracy. A global suitability model of the H5 clade 2.3.4.4 viruses, a group of viruses that recently spread extensively in Asia and the US, shows in comparison a lower spatial extrapolation capacity than the HPAI H5N1 models, with a stronger association with intensively raised chicken densities and anthropogenic factors.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1186/S12936-022-04260-0", "year": 2022, "title": "Identification of factors associated with residual malaria transmission", "abstract": "Abstract\r\n \r\n Background\r\n \r\n Targeted research on residual malaria transmission is important to improve strategies in settings pursuing elimination, where transmission reductions prove challenging. This study aimed to detect and characterize spatial heterogeneity and factors associated with\r\n Plasmodium falciparum\r\n infections and exposure,\r\n P. falciparum\r\n apical membrane antigen 1 (PfAMA1) antibody (Ab) response, in the Central Highlands of Madagascar (CHL).\r\n \r\n \r\n \r\n Methods\r\n \r\n From May to July 2014, a cross-sectional school-based survey was carried out in 182\r\n fokontany\r\n (villages) within 7 health districts of the CHL. Rapid diagnostic tests (RDTs) and a bead-based immunoassay including PfAMA1 antigen biomarker were used to estimate malaria prevalence and seroprevalence, respectively. Local Morans I index was used to detect spatial hotspots. Remotely sensed environmental datatemperature, vegetation indices, land covers, and elevationwere used in multivariable mixed-effects logistic regression models to characterize factors associated with malaria infection and cumulative exposure.\r\n \r\n \r\n \r\n Results\r\n Among 6,293 school-children ages 214 years surveyed, RDT prevalence was low at 0.8% (95% CI 0.61.1%), while PfAMA1 Ab seroprevalence was 7.0% (95% CI 6.47.7%). Hotspots of PfAMA1 Ab seroprevalence were observed in two districts (Ankazobe and Mandoto). Seroprevalence increased for children living > 5 km from a health centre (adjusted odds ratio (OR) = 1.6, 95% CI 1.22.2), and for those experiencing a fever episode in the previous 2 weeks (OR 1.7, 95% CI 1.22.4), but decreased at higher elevation (for each 100-m increase, OR = 0.7, 95% CI 0.60.8). A clear age pattern was observed whereby children 910 years old had an OR of 1.8 (95% CI 1.22.4), children 1112 years an OR of 3.7 (95% CI 2.85.0), and children 1314 years an OR of 5.7 (95% CI 4.08.0) for seropositivity, compared with younger children (28 years).\r\n \r\n \r\n Conclusion\r\n The use of serology in this study provided a better understanding of malaria hotspots and associated factors, revealing a pattern of higher transmission linked to geographical barriers in health care access. The integration of antibody-assays into existing surveillance activities could improve exposure assessment, and may help to monitor the effectiveness of malaria control efforts and adapt elimination interventions.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1097/EE9.0000000000000072", "year": 2019, "title": "Comparison of temperature-mortality associations estimated with different exposure metrics", "abstract": " Background: Studies of the short-term association between ambient temperature and mortality often use temperature observations from a single monitoring station, frequently located at the nearest airport, to represent the exposure of individuals living across large areas. Population-weighted temperature estimates constructed from gridded meteorological data may offer an opportunity to improve exposure assessment in locations where station observations do not fully capture the average exposure of the population of interest. Methods: We compared the association between daily mean temperature and mortality in each of 113 United States counties using (1) temperature observations from a single weather station and (2) population-weighted temperature estimates constructed from a gridded meteorological dataset. We used distributed lag nonlinear models to estimate the 21-day cumulative association between temperature and mortality in each county, 19872006, adjusting for seasonal and long-term trends, day of week, and holidays. Results: In the majority (73.4%) of counties, the relative risk of death on extremely hot days (99th percentile of weather station temperature) versus the minimum mortality temperature was larger when generated from the population-weighted estimates. In contrast, relative risks on extremely cold days (first percentile of weather station temperature) were often larger when generated from the weather station observations. In most counties, the difference in associations estimated from the two temperature metrics was small. Conclusions: In a large, multi-site analysis, temperature-mortality associations were largely similar when estimated from weather station observations versus population-weighted temperature estimates. However, spatially refined exposure data may be more appropriate for analyses seeking to elucidate local health effects. ", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1002/JOC.6391", "year": 2020, "title": "Climatological aspects of the increase of the skin cancer (melanoma)", "abstract": "Ultraviolet radiation (UVR) has a detrimental impact on human health. Overexposures can lead to erythema and DNA damage causing various skin cancers, including the most dangerous melanoma. Recently, a large increase in melanoma incidents has been detected in Europe. We search for a link between the increase of the skin cancer incidence rate and early spring (April) trends in surface UVR and meteorological parameters (temperature, cloudiness, and precipitation) for several European sites: Belsk (Poland), Oslo (Norway), Reading (UK), and Uccle (Belgium). The trends are calculated for the periods of 1980\u20132004 and 2005\u20132018 using ground\u2011based UV measurements and the reconstructed data by a multilinear regression model. The April trends are of special interest because after winter the human skin is not adapted to high UVR intensity and thus susceptible to solar exposure. Statistically insignificant UV trends are found for all stations except for Belsk with the trend of ~5% per 10 years in the former period. Positive trends of 0.5\u20131.0\u00b0C per 10 years (statistically significant) were calculated for all stations in the mean daily maximum temperature of April in the period 1980\u20132018. In April, total ozone values are negatively correlated with the daily maxima of the surface temperature, so if the temperature is higher than 15\u00b0C, the corresponding total ozone values will go below the long\u2011term mean, causing more intense surface UVR. Moreover, high temperatures in April may encourage people to stay longer in the sun and expose parts of the body previously covered by winter clothing, which may result in numerous sunburns yielding a higher risk of melanoma. Thus, social campaigns promoting healthy scenarios of outdoor activities should start earlier than before, that is, at the beginning of spring not just before the summer vacation.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41597-020-0421-Y", "year": 2020, "title": "Provincial and gridded population projection for China under shared socioeconomic pathways from 2010 to 2100", "abstract": "In response to a growing demand for subnational and spatially explicit data on Chinas future population, this study estimates Chinas provincial population from 2010 to 2100 by age (0100+), sex (male and female) and educational levels (illiterate, primary school, junior-high school, senior-high school, college, bachelors, and masters and above) under different shared socioeconomic pathways (SSPs). The provincial projection takes into account fertility promoting policies and population ceiling restrictions of megacities that have been implemented in China in recent years to reduce systematic biases in current studies. The predicted provincial population is allocated to spatially explicit population grids for each year at 30 arc-seconds resolution based on representative concentration pathway (RCP) urban grids and historical population grids. The provincial projection data were validated using population data in 2017 from Chinas Provincial Statistical Yearbook, and the accuracy of the population grids in 2015 was evaluated. These data have numerous potential uses and can serve as inputs in climate policy research with requirements for precise administrative or spatial population data in China.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.EARSCIREV.2015.08.012", "year": 2015, "title": "Developing an adaptive global exposure model to support the generation of country disaster risk profiles", "abstract": "Corresponding to increased realization of the impacts of natural hazards in recent years and the need for quantification of disaster risk, there has been increasing demand from the public sector for openly available disaster risk profiles. Probabilistic disaster risk profiles provide risk assessments and estimates of potential damage to property caused by severe natural hazards. These profiles outline a holistic view of financial risk due to natural hazards, assisting governments in long-term planning and preparedness. A Country Disaster Risk Profile (CDRP) presents a probabilistic estimate of risk aggregated at the national level. A critical component of a CDRP is the development of consistent and robust exposure model to complement existing hazard and vulnerability models. Exposure is an integral part of any risk assessment model, capturing the attributes of all exposed elements grouped by classes of vulnerability to different hazards, and analyzed in terms of value, location and relative importance (e.g. critical facilities and infrastructure). Using freely available (or available at minimum cost) datasets, we present a methodology for an exposure model to produce three independent geo-referenced databases to be used in national level disaster risk profiling for the public sector. These databases represent aggregated economic value at risk at 30 arc-second spatial resolution (approximately 11-km grid at the equator) using a top-down (or downscaling) approach. To produce these databases, the models used are: 1) a building inventory stock model which captures important attributes such as geographical location, urban/rural classification, type of occupancy (e.g. residential and non-residential), building typology (e.g. wood, concrete, masonry, etc.) and economic (replacement) value; 2) a non-building infrastructure density and value model that also corresponds to the fiscal infrastructure portion of the Gross Capital Stock (GCS) of a country; and 3) a spatially and sectorially disaggregated Gross Domestic Product (GDP) model that relates to the production (flow) of goods and services of a country. These models can be adapted to produce - independently or cohesively - a composite exposure database. Finally, we provide an example of the model's use in economic loss estimation for the reoccurrence of the 1882 Mw 7.8 Panama earthquake.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1093/PUBMED/FDZ025", "year": 2020, "title": "Observational evidence of the seasonal and demographic variation in experienced temperature from 77 743 UK Biobank participants", "abstract": "Exposure to cold is known to be associated with severe health impacts. The primary epidemiological evidence for this is the seasonal variation in mortality. However, there is a paucity of directly measured data for personal cold temperature exposure. This paper develops the concept of experienced temperature, and reports how it varies with season, demographics and housing factors.This study uses data from 77 743 UK Biobank participants. A novel method to directly measure participants exposure to low temperatures using a thermistor in a wrist-worn activity monitor is described. These readings are combined with demographic and housing factor variables in a multiple regression model to understand underlying relationships.The study reveals a significant difference in experienced temperature of ~1.8C between the periods of coldest and hottest external temperature. A number of demographic differences were also observedsuch as people of Chinese ethnic background experiencing 0.65C lower temperatures than other groups.This paper presents primary evidence for a seasonal variation in experienced temperature. This variation likely contributes to cold related mortality and morbidity. It is hypothesized that this relationship would be less strong in countries which suffer fewer impacts of cold winter temperatures.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1016/J.SSTE.2019.100317", "year": 2020, "title": "Environmental factors affecting ecological niche of Coccidioides species and spatial dynamics of valley fever in the United States", "abstract": "Coccidioidomycosis is an understudied infectious disease acquired by inhaling fungal spores of Coccidioides species. While historically connected to the southwestern United States, the endemic region for this disease is not well defined. This study's objective was to estimate the impact of climate, soil, elevation and land cover on the Coccidioides species ecological niche. This research used maximum entropy ecological niche modeling based on disease case data from 2015 to 2016. Results found mean temperature of the driest quarter, and barren, shrub, and cultivated land covers influential in characterizing the niche. In addition to hotspots in central California and Arizona, the Columbia Plateau ecoregion of Washington and Oregon showed more favorable conditions for fungus presence than surrounding areas. The identification of influential spatial drivers will assist in future modeling efforts, and the potential distribution map generated may aid public health officials in watching for potential hotspots, assessing vulnerability, and refining endemicity.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1186/S12916-018-1185-5", "year": 2018, "title": "Quantifying the risk of local Zika virus transmission in the contiguous US during the 2015\u20132016 ZIKV epidemic", "abstract": "Local mosquito-borne Zika virus (ZIKV) transmission has been reported in two counties in the contiguous United States (US), prompting the issuance of travel, prevention, and testing guidance across the contiguous US. Large uncertainty, however, surrounds the quantification of the actual risk of ZIKV introduction and autochthonous transmission across different areas of the US.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1038/S41598-020-68230-9", "year": 2020, "title": "How the individual human mobility spatio-temporally shapes the disease transmission dynamics", "abstract": "Human mobility plays a crucial role in the temporal and spatial spreading of infectious diseases. During the past few decades, researchers have been extensively investigating how human mobility affects the propagation of diseases. However, the mechanism of human mobility shaping the spread of epidemics is still elusive. Here we examined the impact of human mobility on the infectious disease spread by developing the individual-based SEIR model that incorporates a model of human mobility. We considered the spread of human influenza in two contrasting countries, namely, Belgium and Martinique, as case studies, to assess the specific roles of human mobility on infection propagation. We found that our model can provide a geo-temporal spreading pattern of the epidemics that cannot be captured by a traditional homogenous epidemic model. The disease has a tendency to jump to high populated urban areas before spreading to more rural areas and then subsequently spread to all neighboring locations. This heterogeneous spread of the infection can be captured by the time of the first arrival of the infection $$(T_{fi} )$$, which relates to the landscape of the human mobility characterized by the relative attractiveness. These findings can provide insights to better understand and forecast the disease spreading.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5539/GJHS.V8N1P1", "year": 2016, "title": "Diseases burden of chronic obstructive pulmonary disease (COPD) attributable to ground-level ozone in Thailand: estimates based on surface monitoring \u2026", "abstract": "Background:\nAmbient ozone (O3) pollution has increased globally since preindustrial times. At present, O3 is one of the major air pollution concerns in Thailand, and is associated with health impacts such as chronic obstructive pulmonary disease (COPD). The objective of our study is to estimate the burden of disease attributed to O3 in 2009 in Thailand based on empirical evidence.\n\nMethods:\nWe estimated disability-adjusted life years (DALYs) attributable to O3 using the comparative risk assessment framework in the Global Burden of Diseases (GBD) study. We quantified the population attributable fraction (PAF), integrated from Geographic Information Systems (GIS)-based spatial interpolation, the population distribution of exposure, and the exposure-response coefficient to spatially characterize exposure to ambient O3 pollution on a national scale. Exposure distribution was derived from GIS-based spatial interpolation O3 exposure model using Pollution Control Department Thailand (PCD) surface air pollution monitor network sources. Relative risk (RR) and population attributable fraction (PAF) were determined using health impact function estimates for O3.\n\nResult:\nPAF (%) of COPD attributable to O3 were determined by region: at approximately, Northern = 2.1, Northeastern = 7.1, Central = 9.6, Eastern = 1.75, Western = 1.47 and Southern = 1.74. The total COPD burden attributable to O3 for Thailand in 2009 was 61,577 DALYs. Approximately 0.6% of the total DALYs in Thailand is male: 48,480 DALYs; and female: 13,097 DALYs.\n\nConclusion:\nThis study provides the first empirical evidence on the health burden (DALYs) attributable to O3 pollution in Thailand. Varying across regions, the disease burden attributable to O3 was 0.6% of the total national burden in 2009. Better empirical data on local specific sites, e.g. urban and rural areas, alternative exposure assessment, e.g. land use regression (LUR), and a local concentration-response coefficient are required for future studies in Thailand.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1002/WFP2.12030", "year": 2021, "title": "Global distribution of forest classes and leaf biomass for use as alternative foods to minimize malnutrition", "abstract": "AbstractDue to the ready availability of tree leaves in many geographies, the alternative food of leaf concentrate currently has the potential to alleviate hunger in over 800 million people. It is therefore potentially highly impactful to determine the edibility of leaf concentrates, which are in the same regions as the world's most undernourished populations. Unfortunately, the toxicity of leaf concentrate for most common tree leaf types has not been screened and the cost of doing so demands a prioritization. This preliminary study explores this potential solution to world hunger by finding the forest classes most likely to offer proximate access to the world's hungry, thus providing the basis for a prioritized list of leaf types to screen for toxicity. Specifically, this study describes a novel methodology for mapping available green leaf biomass and corresponding forest classes (e.g., tropical moist deciduous forest), and their spatial relationship to the global distribution of people who are underweight. These results will be useful for developing a targeted list of tree species to conduct leaf toxicity analysis on, in the interest of developing leaves as an alternative food source for both current malnutrition problems and global catastrophic scenarios.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.5194/AMT-13-6999-2020", "year": 2020, "title": "Validation of the TROPOspheric Monitoring Instrument (TROPOMI) surface UV radiation product", "abstract": "Abstract. The TROPOspheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5 Precursor (S5P) satellite was launched on 13 October 2017 to provide the atmospheric composition for atmosphere and climate research. The S5P is a Sun-synchronous polar-orbiting satellite providing global daily coverage. The TROPOMI swath is 2600 km wide, and the ground resolution for most data products is 7.23.5 km2 (5.63.5 km2 since 6 August 2019) at nadir. The Finnish Meteorological Institute (FMI) is responsible for the development of the TROPOMI UV algorithm and the processing of the TROPOMI surface ultraviolet (UV) radiation product which includes 36 UV parameters in total. Ground-based data from 25 sites located in arctic, subarctic, temperate, equatorial and Antarctic areas were used for validation of the TROPOMI overpass irradiance at 305, 310, 324 and 380 nm, overpass erythemally weighted dose rate/UV index, and erythemally weighted daily dose for the period from 1 January 2018 to 31 August 2019. The validation results showed that for most sites 60 %80 % of TROPOMI data was within 20 % of ground-based data for snow-free surface conditions. The median relative differences to ground-based measurements of TROPOMI snow-free surface daily doses were within 10 % and 5 % at two-thirds and at half of the sites, respectively. At several sites more than 90 % of cloud-free TROPOMI data was within 20 % of ground-based measurements. Generally median relative differences between TROPOMI data and ground-based measurements were a little biased towards negative values (i.e. satellite data < ground-based measurement), but at high latitudes where non-homogeneous topography and albedo or snow conditions occurred, the negative bias was exceptionally high: from 30 % to 65 %. Positive biases of 10 %15 % were also found for mountainous sites due to challenging topography. The TROPOMI surface UV radiation product includes quality flags to detect increased uncertainties in the data due to heterogeneous surface albedo and rough terrain, which can be used to filter the data retrieved under challenging conditions.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1186/S12939-020-01371-5", "year": 2021, "title": "Exploring country-wide equitable government health care facility access in Uganda", "abstract": "Rural access to health care remains a challenge in Sub-Saharan Africa due to urban bias, social determinants of health, and transportation-related barriers. Health systems in Sub-Saharan Africa often lack equity, leaving disproportionately less health center access for the poorest residents with the highest health care needs. Lack of health care equity in Sub-Saharan Africa has become of increasing concern as countries enter a period of simultaneous high infectious and non-communicable disease burdens, the second of which requires a robust primary care network due to a long continuum of care. Bicycle ownership has been proposed and promoted as one tool to reduce travel-related barriers to health-services among the poor.", "labels": [ { "id": 14, "name": "Public Health" } ] }, { "doi": "10.1371/JOURNAL.PNTD.0006143", "year": 2018, "title": "Understanding the legal trade of cattle and camels and the derived risk of Rift Valley Fever introduction into and transmission within Egypt", "abstract": "Rift Valley Fever (RVF) is a mosquito-borne zoonosis, which may cause significant losses for the livestock sector and have serious public health implications. Egypt has been repeatedly affected by RVF epidemics, mainly associated to the importation of animals from sub-Saharan countries, where the disease is endemic. The objective of our study was the improvement of the surveillance and control strategies implemented in Egypt. In order to do that, first we evaluated the legal trade of live animals into and within Egypt. Then, we assessed the risk of Rift Valley Fever virus (RVFV) transmission within the country using a multi-criteria evaluation approach. Finally, we combined the animal trade and the risk of RVFV transmission data to identify those areas and periods in which the introduction of RVFV is more likely. Our results indicate that the main risk of RVFV introduction is posed by the continuous flow of large number of camels coming from Sudan. The risk of RVFV transmission by vectors is restricted to the areas surrounding the Nile river, and does not vary significantly throughout the year. Imported camels are taken to quarantines, where the risk of RVFV transmission by vectors is generally low. Then, they are taken to animal markets or slaughterhouses, many located in populated areas, where the risk of RVFV transmission to animals or humans is much higher. The measures currently implemented (quarantines, vaccination or testing) seem to have a limited effect in reducing the risk of RVFV introduction, and therefore other (risk-based) surveillance strategies are proposed.", "labels": [ { "id": 14, "name": "Public Health" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.FLORA.2020.151609", "year": 2020, "title": "Amazon wildfires: Scenes from a foreseeable disaster", "abstract": "The Amazon forests main protection against fire is its capacity to create a moist understory microclimate. Roads, deforestation, droughts, and climate change have made this natural firebreak less effective. The southern Amazon, in particular, has become more flammable and vulnerable to wildfires during recent droughts. The drought of 1997/98 first showed that fires could escape from agricultural fields and burn standing primary forests that were once considered impenetrable to fire. The spread of forest fires during other 21st-century droughts suggests that this pattern may well be the new normal. With the landscape becoming more flammable, reducing sources of ignition and the negative effects of deforestation is crucial for avoiding severe degradation of Amazon forests. Unfortunately, recent increases in deforestation suggest that Brazil is moving in the opposite direction. Keeping pace with the rapid changes in the regions fire regimes would require innovation; cooperation across political boundaries; and interagency communication on a scale never seen before. While Brazils past success in reducing deforestation suggests that it could be an effective leader in this regard, its sluggish response to the 2019 fires tells quite a different story. But the fact remains that the future of the Amazon depends on decisive action now.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 20, "name": "Wildfires" }, { "id": 4, "name": "Droughts" } ] }, { "doi": "10.1016/J.LANDURBPLAN.2022.104493", "year": 2022, "title": "Imposing consistent global definitions of urban populations with gridded population density models: Irreconcilable differences at the national scale", "abstract": "No common global definition exists of urban populations, resulting in a lack of shared standards across countries for equivalent comparisons. Therefore, I used global population models of Landscan, Worldpop, and Gridded Population of the World to generate a provisional classification of population density classes to define urban and rural by human population densities, which is an enduring attribute to differentiate urban lands from rural lands. I calibrated 2015 population density models to the United Nations 2015 global urban population estimate of 53.9% and then balanced among the population models to reach approximately the same population percentages for rural, exurban, suburban, and urban thresholds. Because the three population models varied in population distribution, with the greatest concentration of population densities in the Landscan model and the greatest dispersion in the Gridded Population of the World, different urban density thresholds were necessary for each population model. After calibration, Worldpop, which is available from years 2000 to 2020, closely matched global urban population estimates during those years. However, without an inconstant definition, for example across populous countries, low urban percentages were not plausible in India simultaneously with moderate urban percentages in China and high urban percentages in the United States. All three population models with adjusted thresholds agreed on a divergent reported urbanized or rural status for 32 countries, representing about 30% of the global population, and greatly reduced urban percentages for another 13 countries. Reconsideration of the urban status of these countries, and the surrounding regions, may change the narrative of urban condition trajectories, prospects, and related applications for research, planning, and management. While population models and adjustments to population density thresholds are not perfect, omitting multifaceted social, economic, political, and demographic histories, they do create a pathway for comparison of urban status across countries on an equal basis, unlike urban definitions that vary by country.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS13173385", "year": 2021, "title": "Characterizing Small-Town Development Using Very High Resolution Imagery", "abstract": "While remotely sensed images of various resolutions have been widely used in identifying changes in urban and peri-urban environments, only very high resolution (VHR) imagery is capable of providing the information needed for understanding the changes taking place in remote rural environments, due to the small footprints and low density of man-made structures in these settings. However, limited by data availability, mapping man-made structures and conducting subsequent change detections in remote areas are typically challenging and thus require a certain level of flexibility in algorithm design that takes into account the specific environmental and image conditions. In this study, we mapped all buildings and corrals for two remote villages in Mozambique based on two single-date VHR images that were taken in 2004 and 2012, respectively. Our algorithm takes advantage of the presence of shadows and, through a fusion of both spectra- and object-based analysis techniques, is able to differentiate buildings with metal and thatch roofs with high accuracy (overall accuracy of 86% and 94% for 2004 and 2012, respectively). The comparison of the mapping results between 2004 and 2012 reveals multiple lines of evidence suggesting that both villages, while differing in many aspects, have experienced substantial increases in the economic status. As a case study, our project demonstrates the capability of a coupling of VHR imagery with locally adjusted classification algorithms to infer the economic development of small, remote rural settlements.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3389/FENVS.2020.00021", "year": 2020, "title": "Mapping land use land cover change in the Lower Mekong Basin from 1997 to 2010", "abstract": "The Lower Mekong Basin (LMB) is biologically diverse, economically important, and home to about 65 million people. The region has undergone extensive environmental changes since the 1990s due to such factors as agricultural expansion and intensification, deforestation, more river damming, increased urbanization, growing human populations, expansion of industrial forest plantations, plus frequent natural disasters from flooding and drought. The Mekong river is also heavily used for human transportation, fishing, drinking water, and irrigation. This paper discusses use of pre-existing LULC maps from 1997 and 2010 to derive a LMB regional LULC change map for 9 classes per date using GIS overlay techniques. The change map was derived to aid SWAT hydrologic modeling applications in the LMB, given the 2010 map is currently used in multiple LMB SWAT models, whereas the 1997 map was previously used. The 2010 LULC map was constructed from Landsat and MODIS satellite data, while the 1997 map was from before the MODIS era and therefore based on available Landsat data. The 19972010 LULC change map showed multiple trends. Permanent agriculture had expanded in certain sub-basins into previously forested areas. Some agricultural areas were converted to industrial forest plantations. Extensive forest changes also occurred in some locations, such as areas changed to shifting cultivation or permanent crops. Also, the 1997 map under classified some urban areas, whereas the 2010 LULC map showed improved identification of such areas. LULC map accuracy were assessed for 213 randomly sampled locations. The 1997 and 2010 LULC maps showed high overall agreements with reference data exceeding 87%. The LULC change map yielded a moderately high level of overall agreement (78%) that improved to 83% once LULC classification scheme specificity was reduced (forests and agriculture were each mapped as singular classes). The change map regionally showed a 4% decrease in agriculture and a 4% increase in deciduous and evergreen forests combined, though deforestation hot spot areas also were evident. The project yielded LULC map data sets that are now available for aiding additional studies that assess LMB LULC change and the impacts such change may pose to water, agriculture, forestry, and disaster management efforts. More work is needed to map, quantify and assess LULC change since 2010 and to further update the 2010 LULC map currently used in the LMB SWAT models.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.3929/ETHZ-B-000353122", "year": 2019, "title": "Cartographic Technique and Artifice: The Case of the Chengdu Plain", "abstract": "Processes of urbanisation in many parts of monsoon Asia have given rise to extensive, hybrid urban-rural regions around and between major metropolitan centres over the past two decades. Such is their novelty and complexity that the state agencies responsible for planning them have found it difficult to describe and analyse them with existing cartographic conventions. Maps produced by such agencies have become more sophisticated with the incorporation of remotely sensed satellite data. The increasing availability of dynamic and crowd-sourced data, on public social media and private/state-owned telecommunication platforms, has further sensitised agencies to the temporal dimensions of planning such regions. Even so, it has been difficult to account for the fine-grained land-use mosaic, mixture of agricultural and non-agricultural patterns, small land holdings, relatively high population densities, and spatial extension across multiple administrative jurisdictions that characterise Asian extended urban-rural regions.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.APGEOG.2020.102277", "year": 2020, "title": "Urban hydrodynamics in the planned township of New Town, West Bengal, India", "abstract": "Unsustainable urbanisation has radically deteriorated the natural hydrological phenomena within cityscapes of developing countries. Such neo-urban spaces have inadvertently disrupted the hydrological balance both within and around themselves. As a result, tumultuous hydro-dynamism is being faced in atmospheric and sub-surface locales of even small planned neo-urban townships like New Town, West Bengal, wherein rainfall regimes, evapo-transpiration rates(ET), land surface temperatures(LST) and groundwater levels, have been affected. Using Built-up Index to identify the spectacular urban growth, TRMM rainfall data, MODIS 11B3 LST and MODIS 16A2 ET rates have been further correlated 3 dimensionally as well as statistically, to understand the changing hydrological regime of the township for two time periods, i.e., 2001-02 and 201819. The variables were found to be significantly related, and partial aggressors for average piezometric fall. Results from average annual estimates depict that over the past 18 years of urban growth of New Town, rainfall has decreased by 10 mm(112 mm), LST has increased by 5 units(300 Celsius), while ET values have decreased by 3units(5 mm/year). Groundwater level data acquired from the Central Groundwater Board Reports, further state that other than groundwater over-extraction by the denizens, there is a 13% chance that the 46 mbgl fall may be attributed to the changing urban hydrology. Future predictions using annual average data state that rainfall will decrease to 102 mm, while LST might escalate to around 3537 and 29-300 Celsius during day-time and night-time, respectively. Piezometric fall and ET rates will plummet to around 20-30mbgl and 2-0.8 mm/year, respectively, causing undue stress to neighbouring zones.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.RSE.2022.113367", "year": 2023, "title": "Quantifying aboveground biomass dynamics from charcoal degradation in Mozambique using GEDI Lidar and Landsat", "abstract": "Understanding changes to aboveground biomass (AGB) in forests undergoing degradation is crucial for accurately and completely quantifying carbon emissions from forest loss and for environmental monitoring in the context of climate change. Monitoring forest degradation as compared to deforestation presents technical challenges because degradation involves widespread, low-intensity AGB removal under varying temporal dynamics. Charcoal production is a key driver for forest degradation in Africa and is projected to increase in the future years. In Sub-Saharan Africa (SSA), where charcoal production drives widespread ABG removal, the utility of optical remote sensing for degradation quantification is challenged by the large inter-seasonal variation and high complexities in ecosystem structure. Limited field measurements on tree structure and aboveground biomass density (AGBD) in many parts of the SSA also impose constraints. In this study, we present a novel data fusion approach combining 3D forest structure from NASA's GEDI Lidar with optical time-series data from Landsat to quantify biomass losses associated with charcoal-related forest degradation over a 10-year time period. We used machine learning models with Landsat spectral indices from the time period of limited hydric stress (LHS) as predictor variables. By applying the best performing Random Forest (RF) model to LandTrendr-stabilized annual LHS Landsat composites, we produced annual forest AGBD maps from 2007 to 2019 over the Mabalane district in southern Mozambique where the dry forest ecosystem was under active charcoal-related degradation since 2008. The RF model achieved an RMSE value of 7.05 Mg/ha (RMSE% = 42%) and R2 value of 0.64 using a 10-fold cross-validation dataset. We quantified a total AGB loss of 2.12 0.06 Megatons (Mt) over the 10-year period, which is only 6.35 2.56% less than the total loss estimated using field-based data as previously published for the same area and time. In addition to quantifying biomass loss, we constructed annual AGBD maps that enabled the characterization of disturbance and recovery. Our framework demonstrates that fusing GEDI and Landsat data through predictive modeling can be used to quantify past forest AGBD dynamics in low biomass forests. This approach provides a satellite-based method to support REDD+ monitoring and evaluation activities in areas where field data is limited and has the potential to be extended to investigate a variety of different disturbance events.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S11769-018-0985-Z", "year": 2018, "title": "Comparative study on changes of croplands between North Korea and South Korea during 1990\u20132015", "abstract": "Studies on long-term change of cropland is of great significance to the utilization of land resources and the implementation of scientific agricultural policies. The Korean Peninsula, adjacent to China, plays an important role in the international environment of Northeast Asia. The Korean Peninsula includes South Korea and North Koreatwo countries that have a great difference in their institutions and economic developments. Therefore, we aim to quantify the spatiotemporal changes of croplands in these two countries using Landsat Thematic Imager (TM) and Operational Land Imager (OLI) imagery, and to compare the differences of cropland changes between the two countries. This paper take full advantage of ODM approach (object-oriented segmentation and decision-tree classification based on multi-season imageries) to obtain the distribution of croplands in 1990 and 2015. Results showed that the overall classification accuracy of cropland data is 91.10% in 1990 and 92.52% in 2015. The croplands were mainly distributed in areas with slopes that were less than 8 and with elevations that were less than 300 m in the Korean Peninsula. However, in other region (slope > 8 or elevation > 300 m), the area and proportion of North Koreas croplands were significantly higher than that of South Korea. Croplands significantly increased by 15.02% in North Korea from 1990 to 2015. In contrast, croplands in South Korea slightly decreased by 1.32%. During the 25 years, policy shift, economic development, population growth, and urban sprawl played primary roles for cropland changes. Additionally, the regional differences of cropland changes were mainly due to different agriculture policies implemented by different countries. The achievements of this study can provide scientific guidance for the protection and sustainability of land resources.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1002/JOC.5973", "year": 2019, "title": "Global observed and modelled impacts of irrigation on surface", "abstract": "Agricultural irrigation has significant potential for altering local climate by reducing soil albedo, increasing evapotranspiration, and enabling greater leaf area. Numerous studies using regional or global climate models have demonstrated the cooling effects of irrigation on mean and extreme temperature, especially over regions where irrigation is extensive. However, these modelbased results have not been well validated due to the limitations of observational data sets. In this study, multiple satellitebased products, including the Moderate Resolution Imaging Spectroradiometer (MODIS) and Soil Moisture Active Passive (SMAP) data sets, are used to isolate and quantify the local impacts of irrigation on surface climate over irrigated regions, which are derived from the Global Map of Irrigation Areas (GMIA). The relationships among soil moisture, albedo, evapotranspiration, and surface temperature are explored. Strong evaporative cooling by irrigation lowers daytime surface temperature over arid and semiarid regions, such as California's Central Valley, the Great Plains, central Asia, and northwestern India. However, the cooling effects are less evident in areas of eastern China and the Lower Mississippi River Basin despite extensive irrigation over these regions. Results are also compared with irrigation experiments using the Community Earth System Model (CESM) to assess the model's ability to represent landatmosphere interactions in regards to irrigation. CESM greatly underestimates the surface temperature response to irrigation. The comparison between the offline and coupled simulations suggests that the irrigationinduced cooling can be regulated by the interactions between land surface and atmosphere, and amplified signals are found over the hot spot regions. Meanwhile, model resolution can also influence the magnitude of the local cooling by irrigation.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1175/JHM-D-16-0208.1", "year": 2017, "title": "Observations of increased cloud cover over irrigated agriculture in an arid environment", "abstract": "Abstract Irrigated agriculture accounts for 20% of global cropland area and may alter climate locally and globally, but feedbacks on clouds and rainfall remain highly uncertain, particularly in arid regions. Nonrenewable groundwater in arid regions accounts for 20% of global irrigation water demand, and quantifying these feedbacks is crucial for the prediction of long-term water use in a changing climate. Here, satellite data are used to show how irrigated crops in an arid environment alter land surface properties, cloud cover, and rainfall patterns. Land surface temperatures (LSTs) over the cropland are 57 K lower than their surroundings, despite a lower albedo, suggesting that Bowen ratio is strongly reduced (and latent heat fluxes increased) over the irrigated cropland. Daytime cloud cover is increased by up to 15% points (a relative increase of 60%), with increased cloud development in the morning and a greater afternoon peak in cloud. Cloud cover is significantly correlated with interannual variations in vegetation and LST. Afternoon rainfall also appears to be enhanced around the irrigation. The cloud feedback is the opposite of what has been previously observed in tropical and semiarid regions, suggesting different processes drive landatmosphere feedbacks in very dry environments. Increased cloud and rainfall, and associated increases in diffuse radiation and reductions in temperature, are likely to benefit vegetation growth. Predictions of changes in crop productivity due to climate change and the impacts of global land-use change on climate and the use of water resources would therefore benefit from including these effects.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1016/J.JTRANGEO.2020.102929", "year": 2021, "title": "Near \u201creal-time\u201d estimation of excess commuting from open-source data: Evidence from China's megacities", "abstract": "Urban commuting has continuously fascinated scholars and decision-makers. As few people live and work in the same place, there is always excess commuting (i.e., the non-optimal or surplus work travel occurring in cities because people do not minimize their journeys to work for most residents). Traditional commuting data sources (e.g., questionnaires and census surveys) are challenged by small samples, high cost, and low spatiotemporal resolution. In contrast, the big social-sensing data (e.g., smart card and mobile phone data) only consider one or two traffic mode of a route, which is not consistent with the real-life condition. This article proposes a framework for modeling excess commuting based on open-source data of the ten most populous megacities in China. We downloaded residential points of interest (POIs) from Lianjia Real Estate website and obtained workplace POIs from China's AMAP, which is widespread used as Google map. The stratified sampling approach was employed to derive commuting pairs. Both commuting distance and time were obtained by the shortest path under public transportation from AMAP. Then, the linear programming method was employed to calculate the theoretical minimum commuting time and distance of each city. We analyzed the statistical property and spatial distributions of excess commuting and found that (1) commuting distances and time (ranging from 9.1 to18.1 km and from 44.8 to 74.3 minutes) of all ten megacities follow a left-skewed normal distribution; (2) in terms of commute cost, all cities show universal core-periphery patterns where the spatial heterogeneity of the commuting time is more significant than that of distance; (3) for each city, the excess commuting measured by time (i.e. from 0.61 to 0.79) is lower than that measured by distance (i.e. 0.68 to 0.89); and (4) the role of mixing land use, waterbody distribution, and centripetal urbanization on urban commuting distance and time is significant.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1029/2021WR031382", "year": 2021, "title": "Estimating spatially explicit irrigation water use based on remotely sensed evapotranspiration and modeled root zone soil moisture", "abstract": "Estimation of irrigation water use (IWU) is critical to assessing water use efficiency and optimizing water resource allocation. However, diversity in irrigation scheduling, irrigation system, and crop type has imposed restrictions on deriving the accurate spatial distribution of IWU. Existing approaches of deriving IWU may have large uncertainty, due mostly to methodological limitations, inadequate inputs, and the mismatch in spatiotemporal scale between IWU estimates and in situ counterparts. Remote sensing has the potential to provide valuable information on moisture transport, which could unravel water consumption by crops. First, we developed a robust relationship between root zone soil moisture (RZSM) and the ratio of actual evapotranspiration (ETa) to reference ET from the land components of European ReAnalysis-5 (ERA5L) without an irrigation module across the Contiguous United States (CONUS). Second, RZSM under irrigation was derived from the developed relationship and remotely sensed ETa from the operational Simplified Surface Energy Balance (SSEBop) model during 2000-2020. Third, IWU over the two decades was derived based on increases in RZSM and ETa due to irrigation using remotely sensed and model-based variables, along with our derived formulas considering groundwater recharge originating from irrigation. The IWU estimates were fairly reliable compared with reported IWU from the Farm and Ranch Irrigation Survey at the state-level in four years, with the coefficient of determination ranging from 0.74 to 0.84, root mean square error ranging from 1.90 to 2.33 km3/yr, and bias ranging from -0.11 to 0.15 km3/yr. Integration of remotely sensed ETa with ERA5L output resulted in IWU estimates of much higher accuracy than published studies. The IWU estimates across the CONUS reflected an increasing trend (\u223c2.71 km3/yr2) during 2000-2007 but a decreasing trend (\u223c0.90 km3/yr2) during 2008-2020, due to efficient irrigation practices and increased precipitation.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1088/1748-9326/AB96D2", "year": 2020, "title": "Large scale tropical deforestation drives extreme warming", "abstract": "Accelerating deforestation rates in Earth's tropical rainforests have dramatic impacts on local public health, agricultural productivity, and global climate change. We used satellite observations to quantify the local temperature changes in deforested patches of rainforests across the tropics and found local warming larger than that predicted from more than a century of climate change under a worst-case emissions scenario. We show that the most extreme warming is typically found in large patches of deforestation; the combined effects of deforestation and climate change on tropical temperatures present a uniquely difficult challenge to the long term public health, occupational safety, and economic security of tropical populations.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1371/JOURNAL.PONE.0217756", "year": 2019, "title": "Giving credit to reforestation for water quality benefits", "abstract": "While there is a general belief that reforesting marginal, often unprofitable, croplands can result in water quality benefits, to date there have been very few studies that have attempted to quantify the magnitude of the reductions in nutrient (N and P) and sediment export. In order to determine the magnitude of a credit for water quality trading, there is a need to develop quantitative approaches to estimate the benefits from forest planting in terms of load reductions. Here we first evaluate the availability of marginal croplands (i.e. those with low infiltration capacity and high slopes) within a large section of the Ohio River Basin (ORB) to assess the magnitude of the land that could be reforested. Next, we employ the Nutrient Tracking Tool (NTT) to study the reduction in N, P and sediment losses from converting corn or corn/soy rotations to forested lands, first in a case study and then for a large region within the ORB. We find that after reforestation, N losses can decrease by 40 to 80 kg/ha-yr (9597% reduction), while P losses decrease by 1 to 4 kg/ha-yr (9699% reduction). There is a significant influence of local conditions (soils, previous crop management practices, meteorology), which can be considered with NTT and must be taken into consideration for specific projects. There is also considerable interannual and monthly variability, which highlights the need to take the longer view into account in nutrient credit considerations for water quality trading, as well as in monitoring programs. Overall, there is the potential for avoiding 60 million kg N and 2 million kg P from reaching the streams and rivers of the northern ORB as a result of conversion of marginal farmland to tree planting, which is on the order of 12% decrease for TN and 5% for TP, for the entire basin. Accounting for attenuation, this represents a significant fraction of the goal of the USEPA Gulf of Mexico Hypoxia Task Force to reduce TN and TP reaching the dead zone in the Gulf of Mexico, the second largest dead zone in the world. More broadly, the potential for targeted forest planting to reduce nutrient loading demonstrated in this study suggests further consideration of this approach for managing water quality in waterways throughout the world. The study was conducted using computational models and there is a need to evaluate the results with empirical observations.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 19, "name": "Water Quality" } ] }, { "doi": "10.5194/BG-17-4999-2020", "year": 2020, "title": "Assessing impacts of selective logging on water, energy, and carbon budgets and ecosystem dynamics in Amazon forests using the Functionally Assembled \u2026", "abstract": "Abstract. Tropical forest degradation from logging, fire, and fragmentation not only alters carbon stocks and carbon fluxes, but also impacts physical land surface properties such as albedo and roughness length. Such impacts are poorly quantified to date due to difficulties in accessing and maintaining observational infrastructures, as well as the lack of proper modeling tools for capturing the interactions among biophysical properties, ecosystem demography, canopy structure, and biogeochemical cycling in tropical forests. As a first step to address these limitations, we implemented a selective logging module into the Functionally Assembled Terrestrial Ecosystem Simulator (FATES) by mimicking the ecological, biophysical, and biogeochemical processes following a logging event. The model can specify the timing and aerial extent of logging events, splitting the logged forest patch into disturbed and intact patches; determine the survivorship of cohorts in the disturbed patch; and modifying the biomass and necromass (total mass of coarse woody debris and litter) pools following logging. We parameterized the logging module to reproduce a selective logging experiment at the Tapajos National Forest in Brazil and benchmarked model outputs against available field measurements. Our results suggest that the model permits the coexistence of early and late successional functional types and realistically characterizes the seasonality of water and carbon fluxes and stocks, the forest structure and composition, and the ecosystem succession following disturbance. However, the current version of FATES overestimates water stress in the dry season and therefore fails to capture seasonal variation in latent and sensible heat fluxes. Moreover, we observed a bias towards low stem density and leaf area when compared to observations, suggesting that improvements are needed in both carbon allocation and establishment of trees. The effects of logging were assessed by different logging scenarios to represent reduced impact and conventional logging practices, both with high and low logging intensities. The model simulations suggest that in comparison to old-growth forests the logged forests rapidly recover water and energy fluxes in 1 to 3 years. In contrast, the recovery times for carbon stocks, forest structure, and composition are more than 30 years depending on logging practices and intensity. This study lays the foundation to simulate land use change and forest degradation in FATES, which will be an effective tool to directly represent forest management practices and regeneration in the context of Earth system models.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1007/S10342-021-01366-Z", "year": 2021, "title": "Recent forest area increase in Europe: Expanding and regenerating forests differ in their regional patterns, drivers and productivity trends", "abstract": "In Europe, forest area is increasing. These recently established forests can be classified into regenerating after disturbances or expanding into agricultural areas after abandonment. We used European Space Agency land cover maps and MODIS data to investigate which socioenvironmental drivers influenced recent forest expansion and regeneration in Europe from 1992 to 2015 and to compare their productivity by means of the Enhanced Vegetation Index (EVI). Our results showed that forest area increased in Europe by 1.4% from 1992 to 2015. The 66% of this forest area increase corresponded to forest expansion mostly in Mediterranean and temperate regions, while regeneration (34%) dominated in boreal areas. Forest area and land cover diversity in 1992 were the main drivers of local forest area increase from 1992 to 2015. Forest expansion occurred on the warmer zones far from urban areas in the boreal region while it was the opposite in temperate and Mediterranean areas. On the other hand, forest regeneration showed mostly a positive relation with the distance to urban areas and water availability but no relation with temperature. The EVI values in 2015 were higher in expanding than in regenerating forests except in the warmer and drier bioclimates of Europe. These EVI trends suggest a higher productivity of expanding forests, except in areas where they cannot benefit from biological and physicochemical legacies of abandoned agricultural soils for tree growth, owing to water shortage. In sum, our results highlight that recent forest area increase in Europe is mostly caused by forest expansion into former agricultural areas but this is mostly occurring in less productive (warmer and drought-prone) bioclimates where advantages of agricultural legacies may not occur. Ultimately, this casts doubts whether there may be a limit for the role of forest expansion into agricultural areas for carbon sequestration in the long term.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1007/S12517-021-06748-6", "year": 2021, "title": "Evaluation of urban land green utilization efficiency with a view of GIS images", "abstract": "The city is at the center of the growing strategy. There are high-cost issues with the production of energy and the environment. The strategy for environmentally friendly and sustainable development is limited. Therefore, if we assess the productivity of urban land use, it is of far-reaching value to use the idea of green growth as an assessment index. On the basis of input, planned production, and unforeseen output, nine indicators, including urban fixed capital stock, secondary and tertiary value-added, and SO2 emissions, are selected to create a research framework and related assessment indicators for the green use of urban land. Related data on the efficiency of urban land use in 12 districts and counties were collected from 2012 to 2018 to assess the efficiency of green land use in urban areas. The findings show that the productivity of green land use decreased significantly during the study period. Many cities in the province have set up a large number of industries, including those with high emissions and high usage. These industries have relocated inland from the eastern coastal regions, resulting in a decline in the rate of urban land use of green land in many towns. If we want to solve this issue, we need to change the framework of land use to follow empirical and fair methods for the rational use of land, to promote the green use of land, and to increase the level of assessment in order to improve the efficiency of green land use.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1016/J.AGWAT.2022.107764", "year": 2022, "title": "Remote sensing of field-scale irrigation withdrawals in the central Ogallala aquifer region", "abstract": "For agricultural areas facing water scarcity, sustainable water use policy relies on irrigation information that is timely and at a high resolution, but existing publicly available water use data are often insufficient for monitoring compliance or understanding the influence of policy on individual farmer decisions. This study attempts to fill this data gap by using remote sensing to map annual irrigation quantity at the field-scale within the central Ogallala aquifer region of the United States. We compiled in situ annual irrigation volume data at the field scale in the Republican River Basin of Colorado for 20152018 and at the Public Land Survey System (PLSS) section scale in western Kansas for 20002016, which served as reference data in random forest models that relied on Landsat-based actual evapotranspiration from the Operational Simplified Surface Energy Balance model (SSEBop) along with maps of irrigated area, Landsat spectral indices, climate, soils, and derived hydrologic variables. The models explained 87% of the variability in irrigation volume in Colorado and 75% in Kansas, but accuracy declined when transferring the models in spatial cross-validation (Colorado R2 =0.81; Kansas R2 =0.51) and temporal cross-validation (Colorado R2 =0.82; Kansas R2 =0.68). Predicted annual totals of irrigation volume in western Kansas had a mean absolute error of 11.9%, which was slightly higher than the average annual change of 11%. Use of predicted irrigation maps also lead to an underestimated effect size for a water use restriction policy in Kansas. These results indicate that field- and section-scale irrigation can be mapped with reasonable accuracy within a region and time period that has adequate sample data, but that methods may need to be improved for applying the models more broadly in areas that lack extensive in situ irrigation data to support further research on water use and aid in structuring policy.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1088/1748-9326/AC2E86", "year": 2021, "title": "Global migration is driven by the complex interplay between", "abstract": "Migration manifests an important response and adaptation measure to changes in the environment and socioeconomic conditions. In a time when environmental stressors and risks are unprecedentedly increasing, understanding the interplay between the underlying factors driving migration is of high importance. While the relationships between environmental and socioeconomic drivers have been identified conceptually, the comprehensive global-scale spatial quantification of their interactions is in its infancy. Here, we performed a geospatial analysis of gridded global net migration from 1990 to 2000 using a novel machine learning approach which analyses the interplay between a set of societal and environmental factors simultaneously at the place of origins (areas of net-negative migration) and destinations (areas of net-positive migration). We diagnosed the importance of eight environmental and societal factors in explaining migration for each country, globally. Nearly half of global in- and out-migration took place in the areas characterized by low adaptive capacity and high environmental stress. Regardless of the income level, income was the key factor in explaining net-migration in half of the countries. Slow-onset environmental factors, drought and water risk, were found to be the dominant environmental variables globally. Our study highlights that factors representing human capacity need to be incorporated into the quantitative diagnosis of environmental migration more rigorously.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.1080/12265934.2020.1803105", "year": 2020, "title": "Driving effects of urbanization on city-level carbon dioxide emissions: from multiple perspectives of urbanization", "abstract": "Cities have emerged as first responders in carbon dioxide emission reduction. However, it is a great dilemma for cities to reach high urbanization level and achieve carbon dioxide emission reduction. Chinese cities are in high speed of urbanization process both in urban-rural population structure change and land-use change. Although there are a large body of research studies exploring urbanization-carbon dioxide emission nexus, some limitations remain. Firstly, most research studies only one-sidedly define urbanization as demographic urbanization, but fail to focus on its land-use change; secondly, present studies more tend to reveal the relationship between urbanization and carbon dioxide emissions, but do not recognize main contributors. Thus, this study aims to explore the urbanization-carbon dioxide emission nexus in South Jiang Province during 20002016. Panel data model and impulse response function based on a vector autoregression (VAR) model are established as the methodology framework. Expressly, urban built-up area, entire built-up area and urban road area are selected to depict land-use change in urbanization process. The results indicate that population and gross regional domestic product (GRDP) are positively correlated with carbon dioxide emissions. The entire built-up area and urban road area are positively correlated with carbon dioxide emissions, while urban built-up area is negatively correlated with carbon dioxide emissions. However, there is little evidence to support the connection between demographic urbanization and carbon dioxide emissions. It is proved that all independent variables impact CO2 emissions in the long run in South Jiangsu Province. Importantly, population and GRDP remain the main contributors of carbon dioxide emissions, compared with urbanization. As such, it is more necessary for South Jiangsu Province to control the upsurge economy and population, especially the migration population. Concentrating compact city development is also critical. These policy implications are also for other Chinese cities.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ESD-9-663-2018", "year": 2018, "title": "The biomass burning contribution to climate\u2013carbon-cycle feedback", "abstract": "Abstract. Temperature exerts strong controls on the incidence and severity of fire. All else equal, warming is expected to increase fire-related carbon emissions, and thereby atmospheric CO2. But the magnitude of this feedback is very poorly known. We use a single-box model of the land biosphere to quantify this positive feedback from satellite-based estimates of biomass burning emissions for 20002014 CE and from sedimentary charcoal records for the millennium before the industrial period. We derive an estimate of the centennial-scale feedback strength of 6.5 3.4 ppm CO2 per degree of land temperature increase, based on the satellite data. However, this estimate is poorly constrained, and is largely driven by the well-documented dependence of tropical deforestation and peat fires (primarily anthropogenic) on climate variability patterns linked to the El NinoSouthern Oscillation. Palaeo-data from pre-industrial times provide the opportunity to assess the fire-related climatecarbon-cycle feedback over a longer period, with less pervasive human impacts. Past biomass burning can be quantified based on variations in either the concentration and isotopic composition of methane in ice cores (with assumptions about the isotopic signatures of different methane sources) or the abundances of charcoal preserved in sediments, which reflect landscape-scale changes in burnt biomass. These two data sources are shown here to be coherent with one another. The more numerous data from sedimentary charcoal, expressed as normalized anomalies (fractional deviations from the long-term mean), are then used together with an estimate of mean biomass burning derived from methane isotope data to infer a feedback strength of 5.6 3.2 ppm CO2 per degree of land temperature and (for a climate sensitivity of 2.8 K) a gain of 0.09 0.05. This finding indicates that the positive carbon cycle feedback from increased fire provides a substantial contribution to the overall climatecarbon-cycle feedback on centennial timescales. Although the feedback estimates from palaeo- and satellite-era data are in agreement, this is likely fortuitous because of the pervasive influence of human activities on fire regimes during recent decades.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.32468/DTSERU.303", "year": 2021, "title": "State Failure, Violence, and Trade: Dangerous Trade Routes in Colombia", "abstract": "We investigate the effect of domestic armed violence brought about by political instability on the geography of distance frictions in freight mobility and the resulting differential access of regions to global markets. The Colombian transportation system has been found to be impeded by deficiencies in landside transport infrastructure and institutions, and by fragmented political environments. The micro-level analysis of U.S.-bounded export shipping records corroborates that export freight shipping from inland regions is re-routed to avoid exposures to domestic armed violence despite greatly extended landside and maritime shipping distances. We exploit the trajectories of freight shipping from Colombian regions and spatial patterns of violent armed conflicts to see how unstable geopolitical environments are detrimental to freight shipping mobility and market openness. The discrete choice model shows that the shipping flow is greatly curbed by the extended re-routing due to domestic armed violence and that inland regions have restricted access to the global market. The perception of risk and re-routing behavior is found heterogeneous across shipments and conditional to shipment characteristics, such as commodity type, freight value and shipper sizes. The results highlight that political stability must be accommodated for improved freight mobility and export-oriented economic development in the global South.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.5194/ACP-22-9389-2022", "year": 2022, "title": "Biomass burning and marine aerosol processing over the southeast Atlantic Ocean: a TEM single-particle analysis", "abstract": "Abstract. This study characterizes single-particle aerosol composition from filters collected during the ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES) and CLoudAerosolRadiation Interaction and Forcing: Year 2017 (CLARIFY-2017) campaigns. In particular the study describes aged biomass burning aerosol (BBA), its interaction with the marine boundary layer and the influence of biomass burning (BB) air on marine aerosol. The study finds evidence of BBA influenced by marine boundary layer processing as well as sea salt influenced by BB air. Secondary chloride aerosols were observed in clean marine air as well as in BB-influenced air in the free troposphere. Higher-volatility organic aerosol appears to be associated with increased age of biomass burning plumes, and photolysis or oxidation may be a mechanism for the apparent increased volatility. Aqueous processing and interaction with the marine boundary layer air may be a mechanism for the presence of sodium on many aged potassium salts. By number, biomass burning potassium salts and modified sea salts are the most observed particles on filter samples. The most commonly observed BC coatings are inorganic salts. These results suggest that atmospheric processes such as photolysis, oxidation and cloud processing are key drivers in the elemental composition and morphology of aged BBA. Fresh BBA inorganic salt content, as it has an important role in the particles' ability to uptake water, may be a key driver in how aqueous processing and atmospheric aging proceed.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1029/2020EF001970", "year": 2021, "title": "The Implications of Global Change for the Co\u2010Evolution of Argentina's Integrated Energy\u2010Water\u2010Land Systems", "abstract": "This study seeks to understand how Argentina's energy, water, and land (EWL) systems will co-evolve under a representative array of human and earth system influences, including socioeconomic change, climate change, and climate policy. To capture Argentina's sub-national EWL dynamics in the context of global change, we couple the Global Change Analysis Model with a suite of consistent, gridded sectoral downscaling models to explore multiple stakeholder-engaged scenarios. Across scenarios, Argentina has the economic opportunity to use its vast land resources to satisfy growing domestic and international demand for crops, such as oil (e.g., soy) and biomass. The human (rather than earth) system produces the most dominant changes in mid-century EWL resource use. A Reference scenario characterized by modest socioeconomic growth projects a 40% increase in Argentina's agricultural production by 2050 (relative to 2020) by using 50,000 km2 of additional cropland and 40% more water. A Climate Policy scenario designed to achieve net-zero carbon emissions globally shortly after mid-century projects that Argentina could use 100,000 km2 of additional land (and 65% more water) to grow biomass and other crops. The burden of navigating these national opportunities and challenges could fall disproportionately on a subset of Argentina's river basins. The Colorado and Negro basins could experience moderate-to-severe water scarcity as they simultaneously navigate substantial irrigated crop demand growth and climate-induced declines in natural water availability. Argentina serves as a generalizable testbed to demonstrate that multi-scale EWL planning challenges can be identified and managed more effectively via integrated analysis of coupled human-earth systems.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1016/J.ENVPOL.2020.115849", "year": 2021, "title": "Spatiotemporal variation and distribution characteristics of crop residue burning in China from 2001 to 2018", "abstract": "In this study, we integrated a remote-sensing fire product (MOD14A1) and land-use product (MCD12Q1) to extract the number of crop-residue burning (CRB) spots and the fire radiative power (FRP) in China from 2001 to 2018. Moreover, we conducted three trend analyses and two geographic distribution analyses to quantify the interannual variations and summarize the spatial characteristics of CRB on grid (0.25 0.25) and regional scales. The results indicated that CRB presents distinctive seasonal patterns with each sub-region. All trend analyses suggested that the annual number of CRB spots in China increased significantly from 2001 to 2018; the linear trend reached 2615 spots/year, the Theil-Sen slope was slightly lower at 2557 spots/year, and the Mann-Kendal was 0.75. By dividing the study period into two sub-periods, we found that the five sub-regions presented different trends in the first and second sub-periods; e.g., the Theil-Sen slope of eastern China in the first sub-period (20012009) was 1021 spots/year but was 1599 spots/year in the second period (20102018). This suggests that summer CRB has been effectively mitigated in eastern China since 2010. Further, the average FRP of CRB spots presented a decreasing trend from 27.5 MW/spot in 2001 to only 15.8 MW/spot in 2018; this may be attributable to more scattered CRB rather than aggregated CRB. Collectively, the fire spots, FRP, and average FRP indicated that spring, summer, and autumn CRB had dropped dramatically over previous levels by 2018 due to strict mitigation measures by local governments.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" } ] }, { "doi": "10.3390/RS13030404", "year": 2021, "title": "Estimation of Field-Level NOx Emissions from Crop Residue Burning Using", "abstract": "Crop residue burning is the major biomass burning activity in China, strongly influencing the regional air quality and climate. As the cultivation pattern in China is rather scattered and intricate, it is a challenge to derive an accurate emission inventory for crop residue burning. In this study, we proposed a remote sensing-based method to estimate nitrogen oxide (NOx) emissions related to crop residue burning at the field level over Hubei, China. The new method considers differences in emission factors and the spatial distribution for different crop types. Fire radiative power (FRP) derived from moderate-resolution imaging spectroradiometer (MODIS) was used to quantify NOx emissions related to agricultural biomass combustion. The spatial distribution of different crops classified by multisource remote sensing data was used as an a priori constraint. We derived a new NOx emission database for Hubei from 2014 to 2016 with spatial resolution of 1 1 km. Significant seasonal patterns were observed from the NOx emission database. Peak NOx emission occurring in October was related to the residue burning in late autumn harvesting. Another peak was observed between January and April, which was due to the frequent burning of stubble before spring sowing. Our results were validated by comparing our emission inventory with geostationary satellite observations, previous studies, global fire emission database (GFED), NO2 vertical column densities (VCDs) from ozone monitoring instrument (OMI) satellite observations, and measurements from environmental monitoring stations. The comparisons showed NOx emission from GFED database was 47% lower than ours, while the evaluations from most of the statistical studies were significantly higher than our results. The discrepancies were likely related to the differences of methodology and data sources. The spatiotemporal variations of NOx emission in this study showed strong correlations with NO2 VCDs, which agreed well with geostationary satellite observations. A reasonable correlation between in situ NO2 observations and our results in agricultural regions demonstrated that our method is reliable. We believe that the new NOx emission database for crop residue burning derived in this study can potentially improve the understanding of pollution sources and can provide additional information for the design of pollution control measures.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.3390/HORTICULTURAE8050393", "year": 2022, "title": "Hop: An Emerging Crop in Subtropical Areas in Brazil", "abstract": "Brazil is one of the three largest beer producers in the world. Four basic ingredients are needed as raw material for the production of beer: water, malt, yeast, and hops (Humulus lupulus L.). Until recently, almost all of the hops in Brazil were imported from other countries. However, in the last decade, hop cultivation in Brazil has emerged due to the increase in the number of new craft breweries, which have demanded diversified raw material for the production of various types of beer. Hops is considered a short-day, temperate species, so the major challenge for the development of hop cultivation in Brazil, with high-yield capacity and with local typicity of bitterness and aroma, is the adaptation of cultivars to the photoperiod conditions in subtropical regions. This review addresses the history of hop cultivation in Brazil and characterizes the main climatic elements of three emerging subtropical growing regions located at different latitudes, such as air temperature, photoperiod, solar radiation, and water availability, to provide support for the development of new technologies for hop cultivation, including supplemental lighting, irrigation, and mulching.", "labels": [ { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ACP-21-9643-2021", "year": 2021, "title": "Exploring the elevated water vapor signal associated with the free tropospheric biomass burning plume over the southeast Atlantic Ocean", "abstract": "Abstract. In southern Africa, widespread agricultural fires produce substantial biomass burning (BB) emissions over the region. The seasonal smoke plumes associated with these emissions are then advected westward over the persistent stratocumulus cloud deck in the southeast Atlantic (SEA) Ocean, resulting in aerosol effects which vary with time and location. Much work has focused on the effects of these aerosol plumes, but previous studies have also described an elevated free tropospheric water vapor signal over the SEA. Water vapor influences climate in its own right, and it is especially important to consider atmospheric water vapor when quantifying aerosolcloud interactions and aerosol radiative effects. Here we present airborne observations made during the NASA ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) campaign over the SEA Ocean. In observations collected from multiple independent instruments on the NASA P-3 aircraft (from near-surface to 67 km), we observe a strongly linear correlation between pollution indicators (carbon monoxide (CO) and aerosol loading) and atmospheric water vapor content, seen at all altitudes above the boundary layer. The focus of the current study is on the especially strong correlation observed during the ORACLES-2016 deployment (out of Walvis Bay, Namibia), but a similar relationship is also observed in the August 2017 and October 2018 ORACLES deployments. Using reanalyses from the European Centre for Medium-Range Weather Forecasts (ECMWF) and Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), and specialized WRF-Chem simulations, we trace the plumevapor relationship to an initial humid, smoky continental source region, where it mixes with clean, dry upper tropospheric air and then is subjected to conditions of strong westward advection, namely the southern African easterly jet (AEJ-S). Our analysis indicates that air masses likely left the continent with the same relationship between water vapor and carbon monoxide as was observed by aircraft. This linear relationship developed over the continent due to daytime convection within a deep continental boundary layer (up to 56 km) and mixing with higher-altitude air, which resulted in fairly consistent vertical gradients in CO and water vapor, decreasing with altitude and varying in time, but this water vapor does not originate as a product of the BB combustion itself. Due to a combination of conditions and mixing between the smoky, moist continental boundary layer and the dry and fairly clean upper-troposphere air above (6 km), the smoky, humid air is transported by strong zonal winds and then advected over the SEA (to the ORACLES flight region) following largely isentropic trajectories. Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) back trajectories support this interpretation. This work thus gives insights into the conditions and processes which cause water vapor to covary with plume strength. Better understanding of this relationship, including how it varies spatially and temporally, is important to accurately quantify direct, semi-direct, and indirect aerosol effects over this region.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-18-14889-2018", "year": 2018, "title": "Estimation of black carbon emissions from Siberian fires using satellite observations of absorption and extinction optical depths", "abstract": "Abstract. Black carbon (BC) emissions from open biomass burning (BB) are known to have a considerable impact on the radiative budget of the atmosphere at both global and regional scales; however, these emissions are poorly constrained in models by atmospheric observations, especially in remote regions. Here, we investigate the feasibility of constraining BC emissions from BB using satellite observations of the aerosol absorption optical depth (AAOD) and the aerosol extinction optical depth (AOD) retrieved from OMI (Ozone Monitoring Instrument) and MODIS (Moderate Resolution Imaging Spectroradiometer) measurements, respectively. We consider the case of Siberian BB BC emissions, which have the strong potential to impact the Arctic climate system. Using aerosol remote sensing data collected at Siberian sites of the AErosol RObotic NETwork (AERONET) along with the results of the fourth Fire Lab at Missoula Experiment (FLAME-4), we establish an empirical parameterization relating the ratio of the elemental carbon (EC) and organic carbon (OC) contents in BB aerosol to the ratio of AAOD and AOD at the wavelengths of the satellite observations. Applying this parameterization to the BC and OC column amounts simulated using the CHIMERE chemistry transport model, we optimize the parameters of the BB emission model based on MODIS measurements of the fire radiative power (FRP); we then obtain top-down optimized estimates of the total monthly BB BC amounts emitted from intense Siberian fires that occurred from May to September 2012. The top-down estimates are compared to the corresponding values obtained using the Global Fire Emissions Database (GFED4) and the Fire Emission Inventorynorthern Eurasia (FEI-NE). Our simulations using the optimized BB aerosol emissions are verified against AAOD and AOD data that were withheld from the estimation procedure. The simulations are further evaluated against in situ EC and OC measurements at the Zotino Tall Tower Observatory (ZOTTO) and also against aircraft aerosol measurement data collected in the framework of the Airborne Extensive Regional Observations in SIBeria (YAK-AEROSIB) experiments. We conclude that our BC and OC emission estimates, considered with their confidence intervals, are consistent with the ensemble of the measurement data analyzed in this study. Siberian fires are found to emit 0.410.14 Tg of BC over the whole 5-month period considered; this estimate is a factor of 2 larger and a factor of 1.5 smaller than the corresponding estimates based on the GFED4 (0.20 Tg) and FEI-NE (0.61 Tg) data, respectively. Our estimates of monthly BC emissions are also found to be larger than the BC amounts calculated using the GFED4 data and smaller than those calculated using the FEI-NE data for any of the 5 months. Particularly large positive differences of our monthly BC emission estimates with respect to the GFED4 data are found in May and September. This finding indicates that the GFED4 database is likely to strongly underestimate BC emissions from agricultural burns and grass fires in Siberia. All of these differences have important implications for climate change in the Arctic, as it is found that about a quarter of the huge BB BC mass emitted in Siberia during the fire season of 2012 was transported across the polar circle into the Arctic. Overall, the results of our analysis indicate that a combination of the available satellite observations of AAOD and AOD can provide the necessary constraints on BB BC emissions.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 20, "name": "Wildfires" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10661-021-09259-9", "year": 2021, "title": "Impact of biomass burnings in Southeast Asia on air quality and pollutant transport during the end of the 2019 dry season", "abstract": "At the end of the dry season, March and April in Southeast Asia (SEA), agricultural refuse burnings occur over the region, mainly in the countries of Myanmar, Thailand, Laos, Cambodia and Vietnam, in preparation for the wet rice plantation. In this study, the impact of biomass burnings at the height of the burning period in March 2019 in mainland SEA on air quality and pollutant transport is modelled using the Weather Research Forecast WRF-Chem air quality model with emission input from the National Center for Atmospheric Research (NCAR) Fire Emission Inventory from NCAR (FINN). FINN is derived from satellite remote sensing data and species emission factors. A simulation of the dispersion of pollutants from biomass burnings from 13 to 19 March 2019, when the burnings was most intense, was performed. Validation of the model prediction using observed meteorological and pollutant data such as AOD measurements on ground from AERONET (Aerosol Robotic Network) and data from MODIS and CALIPSO satellites is carried out at various sites in the region. The results show that impact on air quality was most pronounced in Thailand and Laos but the effect of biomass burnings in mainland SEA at the end of the dry season is widespread in terms of pollutant dispersion and population exposure over the whole region and beyond. It is also shown that the transport of pollutants from biomass burnings in SEA to southern China, Taiwan and beyond is facilitated by the Truong Son mountain range, when under westerly wind, acting as a launching pad to uplift the pollutant plumes to higher altitude which then can be dispersed widely and transported farther from the biomass burning sources in Thailand and Laos.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1088/1748-9326/AB2D56", "year": 2019, "title": "Hungry cities: how local food self-sufficiency relates to climate change, diets, and urbanisation", "abstract": "Abstract\r\n \r\n Using a newly developed model approach and combining it with remote sensing, population, and climate data, first insights are provided into how local diets, urbanisation, and climate change relates to local urban food self-sufficiency. In plain terms, by utilizing the global peri-urban (PU) food production potential approximately 1bn urban residents (30% of global urban population) can be locally nourished, whereby further urbanisation is by far the largest pressure factor on PU agriculture, followed by a change of diets, and climate change. A simple global food transport model which optimizes transport and neglects differences in local emission intensities indicates that CO\r\n 2\r\n emissions related to food transport can be reduced by a factor of 10.", "labels": [ { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1029/2020GH000281", "year": 2020, "title": "Environmental Association of Burning Agricultural Biomass in the Indus River Basin", "abstract": "Intensification of smog episodes, following harvesting of paddy crops in agricultural plains of the Indus basin in the Indian subcontinent, are often attributed to farming practice of burning standing stubble during late autumn (October, November) months. Biomass burning (paddy stubble residual) is a preferred technique to clear farmlands for centuries by farmers in that basin. However, despite stable agricultural landholding and yield, smog is being increasingly associated with burning agricultural biomass, thus creating a paradox. Here, we show that the concentration of smog (NOx, PM2.5, SO2) in the ambient air exceeds the safe threshold limits throughout the entire year in the region. This study argues that agricultural biomass burning is an ephemeral event in the basin that may act as a catalyst to a deteriorated air quality in the entire region. Results further demonstrate that simultaneous saturation of air pollutants along with high ambient moisture content and low wind speeds following the monsoon season are strongly related to aggravated smog events. Findings from this study should help make holistic mitigation and intervention policies to monitor air quality for sustainability of public health in agricultural regions where farming activities are a dominant economic driver for society.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.GEOFORUM.2019.08.017", "year": 2019, "title": "Geographical political economy of nuclear power plant closures", "abstract": "Nuclear power had its heyday in the 1970s in the United States, and many of the nuclear power plants constructed during that period are now facing the end of their design life. Consequently, nuclear power plant closures and unsitings are emerging as highly contentious public issues. In an effort to provide a more nuanced account of nuclear power plant closures, we adopt theoretical vantage points from the geographical political economy literature. Our analysis focuses on the articulation and characterization of socio-spatial moments of closure processes rather than enumerating underlying factors in order to better explain variegated plant closure outcomes. For empirical analysis, we examine two contrasting cases of recent conflict over nuclear power plant closure in the northeastern United States, involving the Vermont Yankee and FitzPatrick plants. These closure episodes show marked differences in region-level activism. Yet the presence of these movements alone is insufficient in accounting for particular outcomes (the when and how) of the plant closure controversies. Our analysis highlights the agency of key state actors and their selective deployment of various global and local themes, such as nuclear disaster in Fukushima, global climate change, corporate accountability, and regional economic conditions, to define and promote their goals. Our study also demonstrates how the moments of closure decisions can be opened up by viewing the closure controversies from the owner company side, pointing to the usefulness of not only comparative, but also of connective accounts that highlight spatio-temporal links between closure processes.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1088/1748-9326/AC9E69", "year": 2022, "title": "Marked rebound of agricultural fire emissions in Asia after the outbreak", "abstract": "Abstract\r\n East and South Asia are major hotspots of crop straw burning worldwide, with profound impacts on air quality and climate change. The Northeast China Plain (NECP) and Punjab, India, are two of the most fertile areas for crop production, which have large-scale agricultural fires during post-harvest seasons. Leveraging established fire-emission databases and satellite-retrieved agricultural fire spots, we show that, while the years 2018 and 2019 recorded low agricultural fire emissions in both the NECP and Punjab, probably due to the implementation of crop straw sustainable management, fire emissions markedly rebounded in 2020, reaching about 190% and 150% of 2019 levels, respectively. The COVID-19 lockdown measures somewhat disrupted eco-friendly crop straw management through restrictions on labor and transportation availability, such that farmers may have had to burn off crop wastes to clear up the land. We further demonstrate that the increased fire emissions in the NECP resulted in serious particulate matter pollution during the fire season in spring 2020, as opposed to considerable decreases in particles from fossil fuel emissions caused by the COVID-19 lockdown. This study suggests the unintended impacts of the COVID-19 pandemic on the agricultural sector and human health.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/AMT-14-7929-2021", "year": 2021, "title": "Biomass burning nitrogen dioxide emissions derived from space with TROPOMI: methodology and validation", "abstract": "Abstract. Smoke from wildfires is a significant source of air pollution, which can adversely impact air quality and ecosystems downwind. With the recently increasing intensity and severity of wildfires, the threat to air quality is expected to increase. Satellite-derived biomass burning emissions can fill in gaps in the absence of aircraft or ground-based measurement campaigns and can help improve the online calculation of biomass burning emissions as well as the biomass burning emissions inventories that feed air quality models. This study focuses on satellite-derived NOx emissions using the high-spatial-resolution TROPOspheric Monitoring Instrument (TROPOMI) NO2 dataset. Advancements and improvements to the satellite-based determination of forest fire NOx emissions are discussed, including information on plume height and effects of aerosol scattering and absorption on the satellite-retrieved vertical column densities. Two common top-down emission estimation methods, (1) an exponentially modified Gaussian (EMG) and (2) a flux method, are applied to synthetic data to determine the accuracy and the sensitivity to different parameters, including wind fields, satellite sampling, noise, lifetime, and plume spread. These tests show that emissions can be accurately estimated from single TROPOMI overpasses. The effect of smoke aerosols on TROPOMI NO2 columns (via air mass factors, AMFs) is estimated, and these satellite columns and emission estimates are compared to aircraft observations from four different aircraft campaigns measuring biomass burning plumes in 2018 and 2019 in North America. Our results indicate that applying an explicit aerosol correction to the TROPOMI NO2 columns improves the agreement with the aircraft observations (by about 10 %25 %). The aircraft- and satellite-derived emissions are in good agreement within the uncertainties. Both top-down emissions methods work well; however, the EMG method seems to output more consistent results and has better agreement with the aircraft-derived emissions. Assuming a Gaussian plume shape for various biomass burning plumes, we estimate an average NOx e-folding time of 2 1 h from TROPOMI observations. Based on chemistry transport model simulations and aircraft observations, the net emissions of NOx are 1.3 to 1.5 times greater than the satellite-derived NO2 emissions. A correction factor of 1.3 to 1.5 should thus be used to infer net NOx emissions from the satellite retrievals of NO2.", "labels": [ { "id": 20, "name": "Wildfires" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.1016/J.ERSS.2021.102126", "year": 2021, "title": "The uneven expansion of electricity supply in India: The logics of clientelism, incrementalism and maximin", "abstract": "This study examines the recent massive expansion of electricity supply in India. With data from over 120,000 observations relating to households across the country in 2014 and 2019, we describe the rapid but uneven increases in hours of supply. We compare three distinct logics of public service delivery that may account for different rates of improvement in electricity supply - the logics of clientelism, incrementalism and maximin. The clientelist logic posits that state-level elected representatives target investments toward local areas where they hold small margins of support to improve their chances of re-election. According to the logic of incrementalism, policymakers focus on policies that are closely aligned with existing policies, which implies that supply increases most in locations where surrounding areas have relatively good electricity supply. The maximin logic, by contrast, posits that the greatest improvements take place in locations that previously had the poorest supply. The evidence supports each of the three logics to some extent, but by far the strongest evidence supports the maximin logic.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1088/1748-9326/AB9389", "year": 2020, "title": "Integrated energy-water-land nexus planning to guide national policy: an example from Uruguay", "abstract": "Abstract\r\n Despite broad consensus on the benefits of a nexus approach to multi-sector planning, actual implementation in government and other decision-making institutions is still rare. This study presents an approach to conducting integrated energy-water-land (EWL) planning, using Uruguay as an example. This stakeholder-driven study focuses on assessing the EWL nexus implications of actual planned policies aimed at strengthening three of Uruguays key exports (beef, soy, and rice), which account for more than 40% of total national export revenue. Five scenarios are analyzed in the study: a reference scenario, a climate impacts scenario, and three policy scenarios. The three policy scenarios include measures such as increasing the intensity of beef production while simultaneously decreasing emissions, increasing irrigated soybean production, and improving rice yields. This study supplements previous sector-specific planning efforts in Uruguay by conducting the first stakeholder-driven integrated multi-sector assessment of planned policies in Uruguay using a suite of integrated modeling tools. Key insights from the study are: as compared to a reference scenario, improving beef productivity could lead to cropland expansion (+30%) and significant indirect increases in water requirements (+20%); improving rice yields could lead to increases in total emissions (+3%), which may partially offset emissions reductions from other policies; expanding irrigated soy could have the least EWL impacts amongst the policies studied; and climate-driven changes could have significantly less impact on EWL systems as compared to human actions. The generalizable insights derived from this analysis are readily applicable to other countries facing similar multi-sector planning challenges. In particular, the studys results reinforce the fact that policies often have multi-sector consequences, and thus policies can impact one anothers efficacy. Thus, policy design and implementation can benefit from coordination across sectors and decision-making institutions.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 11, "name": "Habitat Conversion/Fragmentation" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ACP-21-6155-2021", "year": 2021, "title": "Measurement report: Firework impacts on air quality in Metro Manila, Philippines, during the 2019 New Year revelry", "abstract": "Abstract. Fireworks degrade air quality, reduce visibility, alter atmospheric chemistry, and cause short-term adverse health effects. However, there have not been any comprehensive physicochemical and optical measurements of fireworks and their associated impacts in a Southeast Asia megacity, where fireworks are a regular part of the culture. Size-resolved particulate matter (PM) measurements were made before, during, and after New Year 2019 at the Manila Observatory in Quezon City, Philippines, as part of the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex). A high-spectral-resolution lidar (HSRL) recorded a substantial increase in backscattered signal associated with high aerosol loading 440 m above the surface during the peak of firework activities around 00:00 (local time). This was accompanied by PM2.5 concentrations peaking at 383.9 g m3. During the firework event, water-soluble ions and elements, which affect particle formation, growth, and fate, were mostly in the submicrometer diameter range. Total (>0.056 m) water-soluble bulk particle mass concentrations were enriched by 5.7 times during the fireworks relative to the background (i.e., average of before and after the firework). The water-soluble mass fraction of PM2.5 increased by 18.5 % above that of background values. This corresponded to increased volume fractions of inorganics which increased bulk particle hygroscopicity, kappa (), from 0.11 (background) to 0.18 (fireworks). Potassium and non-sea-salt (nss) SO42- contributed the most (70.9 %) to the water-soluble mass, with their mass size distributions shifting from a smaller to a larger submicrometer mode during the firework event. On the other hand, mass size distributions for NO3-, Cl, and Mg2+ (21.1 % mass contribution) shifted from a supermicrometer mode to a submicrometer mode. Being both uninfluenced by secondary aerosol formation and constituents of firework materials, a subset of species were identified as the best firework tracer species (Cu, Ba, Sr, K+, Al, and Pb). Although these species (excluding K+) only contributed 2.1 % of the total mass concentration of water-soluble ions and elements, they exhibited the highest enrichments (6.1 to 65.2) during the fireworks. Surface microscopy analysis confirmed the presence of potassium/chloride-rich cubic particles along with capsule-shaped particles in firework samples. The results of this study highlight how firework emissions change the physicochemical and optical properties of water-soluble particles (e.g., mass size distribution, composition, hygroscopicity, and aerosol backscatter), which subsequently alters the background aerosol's respirability, influence on surroundings, ability to uptake gases, and viability as cloud condensation nuclei (CCN).", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 1, "name": "Air Quality" } ] }, { "doi": "10.5194/ACP-20-2533-2020", "year": 2020, "title": "The impacts of biomass burning activities on convective systems over the Maritime Continent", "abstract": "Abstract. Convective precipitation associated with Sumatra squall lines and diurnal rainfall over Borneo is an important weather feature of the Maritime Continent in Southeast Asia. Over the past few decades, biomass burning activities have been widespread during summertime over this region, producing massive fire aerosols. These additional aerosols, when brought into the atmosphere, besides influencing the local radiation budget through directly scattering and absorbing sunlight, can also act as cloud condensation nuclei or ice nuclei to alter convective clouds and precipitation over the Maritime Continent via so-called aerosol indirect effects. Based on 4-month simulations with or without biomass burning aerosols, conducted using the Weather Research and Forecasting model coupled with a chemistry module (WRF-Chem), we have investigated the aerosolcloud interactions associated with biomass burning aerosols over the Maritime Continent. Results from selected cases of convective events have specifically shown the significant impact of fire aerosols on weak convections by their increasing of the quantities of hydrometeors and rainfall in both the Sumatra and Borneo regions. Statistical analysis over the fire season also suggests that fire aerosols have impacts on the nocturnal convections associated with the local anticyclonic circulation in western Borneo and weaken nocturnal rainfall intensity by about 9 %. Such an effect is likely to have come from the near-surface heating due to absorbing aerosols emitted from fires, which could weaken land breezes and thus the convergence of anticyclonic circulation.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.5194/BG-17-2553-2020", "year": 2020, "title": "Ocean carbonate system variability in the North Atlantic Subpolar surface water (1993\u20132017)", "abstract": "Abstract. The North Atlantic is one of the major ocean sinks for natural and anthropogenic atmospheric CO2. Given the variability of the circulation, convective processes or warmingcooling recognized in the high latitudes in this region, a better understanding of the CO2 sink temporal variability and associated acidification needs a close inspection of seasonal, interannual to multidecadal observations. In this study, we investigate the evolution of CO2 uptake and ocean acidification in the North Atlantic Subpolar Gyre (5064 N) using repeated observations collected over the last 3 decades in the framework of the long-term monitoring program SURATLANT (SURveillance de l'ATLANTique). Over the full period (19932017) pH decreases (0.0017 yr1) and fugacity of CO2 (fCO2) increases (+1.70 atm yr1). The trend of fCO2 in surface water is slightly less than the atmospheric rate (+1.96 atm yr1). This is mainly due to dissolved inorganic carbon (DIC) increase associated with the anthropogenic signal. However, over shorter periods (410 years) and depending on the season, we detect significant variability investigated in more detail in this study. Data obtained between 1993 and 1997 suggest a rapid increase in fCO2 in summer (up to +14 atm yr1) that was driven by a significant warming and an increase in DIC for a short period. Similar fCO2 trends are observed between 2001 and 2007 during both summer and winter, but, without significant warming detected, these trends are mainly explained by an increase in DIC and a decrease in alkalinity. This also leads to a pH decrease but with contrasting trends depending on the region and season (between 0.006 and 0.013 yr1). Conversely, data obtained during the last decade (20082017) in summer show a cooling of surface waters and an increase in alkalinity, leading to a strong decrease in surface fCO2 (between 4.4 and 2.3 atm yr1; i.e., the ocean CO2 sink increases). Surprisingly, during summer, pH increases up to +0.0052 yr1 in the southern subpolar gyre. Overall, our results show that, in addition to the accumulation of anthropogenic CO2, the temporal changes in the uptake of CO2 and ocean acidification in the North Atlantic Subpolar Gyre present significant multiannual variability, not clearly directly associated with the North Atlantic Oscillation (NAO). With such variability it is uncertain to predict the near-future evolution of airsea CO2 fluxes and pH in this region. Thus, it is highly recommended to maintain long-term observations to monitor these properties in the next decade.", "labels": [ { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.AGRFORMET.2020.108167", "year": 2020, "title": "Hydrometeorological sensitivities of net ecosystem carbon dioxide and methane exchange of an Amazonian palm swamp peatland", "abstract": "Tropical peatlands are a major, but understudied, biophysical feedback factor on the atmospheric greenhouse effect. The largest expanses of tropical peatlands are located in lowland areas of Southeast Asia and the Amazon basin. The Loreto Region of Amazonian Peru contains ~63,000 km2 of peatlands. However, little is known about the biogeochemistry of these peatlands, and in particular, the cycling of carbon dioxide (CO2) and methane (CH4), and their responses to hydrometeorological forcings. To address these knowledge gaps, we established an eddy covariance (EC) flux tower in a natural palm (Mauritia flexuosa L.f.) swamp peatland near Iquitos, Peru. Here, we report ecosystem-scale CO2 and CH4 flux observations for this Amazonian palm swamp peatland over a two-year period in relation to hydrometeorological forcings. Seasonal and short-term variations in hydrometeorological forcing had a strong effect on CO2 and CH4 fluxes. High air temperature and vapor pressure deficit (VPD) exerted an important limitation on photosynthesis during the dry season, while latent heat flux appeared to be insensitive to these climate drivers. Evidence from light-response analyses and flux partitioning support that photosynthetic activity was downregulated during dry conditions, while ecosystem respiration (RE) was either inhibited or enhanced depending on water table position. The cumulative net ecosystem CO2 exchange indicated that the peatland was a significant CO2 sink ranging from 465 (279 to 651) g C m2 y1 in 2018 to 462 (277 to 647) g C m2 y1 in 2019. The forest was a CH4 source of 22 (20 to 24) g C m2 y1, similar in magnitude to other tropical peatlands and larger than boreal and arctic peatlands. Thus, the annual carbon budget of this Amazonian palm swamp peatland appears to be a major carbon sink under current hydrometeorological conditions.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1111/GEB.12880", "year": 2019, "title": "Alternative tree-cover states of the boreal ecosystem: A conceptual model", "abstract": "AimPrevious analyses of remotely sensed data detected the multimodality of the tree\u2011cover distribution of the boreal forest, and identified areas with potentially alternative tree\u2011cover states. This paper aims at investigating the causes of multimodality and multistability of the boreal forest, their influence on the asymmetric tree species distribution between Eurasia and North America, and whether multistability could be associated with recent greening trends in leaf area index (LAI) and normalized difference vegetation index (NDVI).LocationEurasian and North American boreal forests.Time period2000\u20132010.Major taxa studiedBoreal forest plant functional types.MethodsWe employ a conceptual model based on tree species competition to simulate the sensitivity of tree cover to stochastic disturbances and to changes in environmental factors. We include different plant functional types based on survival adaptations, and force the model with remotely sensed environmental data. We analyse the model as a dynamical system. We use metrics from statistics and information theory to compare the detection of alternative tree\u2011cover states and greening trends in LAI and NDVI.ResultsWe find that multimodality and multistability can emerge through competition between different plant functional types. Additionally, our model is able to reproduce the asymmetry in tree species distribution between Eurasia and North America. Moreover, changes in permafrost distribution can be associated with phenomenological bifurcation points of the model. Finally, we find that the detection of multistable areas is not affected by recent vegetation trends, whereas shifts between alternative states could have affected the greening trends.Main conclusionsTree\u2011cover multistability in the boreal region can emerge through competition between species subject to periodic disturbances. Changes in permafrost thaw and distribution could be responsible for the asymmetry in tree species distribution between North America and Eurasia. Climate change and permafrost degradation could cause shifts in tree\u2011cover states and dominant species. Recent vegetation greening trends in multistable areas could have been affected by shifts between alternative states.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1029/2020GL089873", "year": 2020, "title": "Eddy-Like Features Near St. Matthew Island, Eastern Bering Sea Shelf:", "abstract": "The eastern Bering Sea Shelf is characterized by high biological productivity, seasonal sea ice, and commercially important fisheries. Enhanced productivity is often associated with small-scale oceanographic features. Our objective was to use an autonomous underwater vehicle to examine features typically missed by ~20-km spaced shipboard sampling. A coastal glider (Oculus) sampled ~3 dives hr-1 with horizontal spacing of ~300 m per dive in August/September 2017. In the north-south transition zone near St. Matthew Island, the glider sampled four eddy-like features associated with weaker vertical stratification. These features had diameters of 15-20 km and were associated with higher surface chlorophyll. Shipboard data collected in the same region approximately a month later showed that a similar feature was associated with high concentrations of small copepods. Incorporating higher resolution sampling available with gliders into the Bering Sea observing network will improve our understanding of ecosystem response to patchiness in the system.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/BG-11-5503-2014", "year": 2014, "title": "Biogeophysical feedbacks enhance the Arctic terrestrial carbon sink in regional Earth system dynamics", "abstract": "Abstract. Continued warming of the Arctic will likely accelerate terrestrial carbon (C) cycling by increasing both uptake and release of C. Yet, there are still large uncertainties in modelling Arctic terrestrial ecosystems as a source or sink of C. Most modelling studies assessing or projecting the future fate of C exchange with the atmosphere are based on either stand-alone process-based models or coupled climateC cycle general circulation models, and often disregard biogeophysical feedbacks of land-surface changes to the atmosphere. To understand how biogeophysical feedbacks might impact on both climate and the C budget in Arctic terrestrial ecosystems, we apply the regional Earth system model RCA-GUESS over the CORDEX-Arctic domain. The model is forced with lateral boundary conditions from an EC-Earth CMIP5 climate projection under the representative concentration pathway (RCP) 8.5 scenario. We perform two simulations, with or without interactive vegetation dynamics respectively, to assess the impacts of biogeophysical feedbacks. Both simulations indicate that Arctic terrestrial ecosystems will continue to sequester C with an increased uptake rate until the 20602070s, after which the C budget will return to a weak C sink as increased soil respiration and biomass burning outpaces increased net primary productivity. The additional C sinks arising from biogeophysical feedbacks are approximately 8.5 Gt C, accounting for 22% of the total C sinks, of which 83.5% are located in areas of extant Arctic tundra. Two opposing feedback mechanisms, mediated by albedo and evapotranspiration changes respectively, contribute to this response. The albedo feedback dominates in the winter and spring seasons, amplifying the near-surface warming by up to 1.35 C in spring, while the evapotranspiration feedback dominates in the summer months, and leads to a cooling of up to 0.81 C. Such feedbacks stimulate vegetation growth due to an earlier onset of the growing season, leading to compositional changes in woody plants and vegetation redistribution.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 13, "name": "Land Surface/Agriculture Indicators" } ] }, { "doi": "10.1002/ECE3.6007", "year": 2020, "title": "The role of geography, environment, and genetic divergence on the distribution of pikas in the Himalaya", "abstract": "Pikas (Ochotona Link, 1795) are high\u2011altitude specialist species making them a useful bioindicator species to warming in high\u2011altitude ecosystem. The Himalayan Mountains are an important part of their range, supporting approximately 23%\u201325% of total pika species worldwide, yet we lack basic information on the distribution patterns. We combine field\u2011based surveys with genetics\u2011based identification and phylogeny to identify differences in species\u2011environment relationships. Further, we suggest putative evolutionary causes for the observed niche patterns.LocationHimalayan high\u2011altitude region.MethodsWe sampled 11 altitudinal transects (ranging from ~2,000 to 5,000 m) in the Himalaya to establish occurrence records. We collected 223 species records using genetic analyses to confirm species' identity (based on some invasive and mostly noninvasive biological samples). Niche and geographic overlap were estimated using kernel density estimates.ResultsMost pikas in the Himalaya span wide elevation ranges and exhibit extensive spatial overlap with other species. However, even in areas of high species diversity, we found species to have a distinct environmental niche. Despite apparent overlapping distributions at broad spatial scales, in our field surveys, we encountered few cases of co\u2011occurrence of species in the sampled transects. Deeply diverged sister\u2011species pair had the least environmental niche overlap despite having the highest geographic range overlap. In contrast, sister\u2011species pair with shallow genetic divergence had a higher environmental niche overlap but was geographically isolated. We hypothesize that the extent of environmental niche divergence in pikas is a function of divergence time within the species complex. We assessed vulnerability of species to future climate change using environmental niche and geographic breadth sizes as a proxies. Our findings suggest that O. sikimaria may be the most vulnerable species. Ochotona roylii appears to have the most unique environmental niche space, with least niche overlap with other pika species from the study area.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1093/JHERED/ESAC025", "year": 2022, "title": "Landscape connectivity and genetic structure in a mainstem and a tributary stonefly (Plecoptera) species using a novel reference genome", "abstract": "Understanding how environmental variation influences population genetic structure can help predict how environmental change influences population connectivity, genetic diversity, and evolutionary potential. We used riverscape genomics modeling to investigate how climatic and habitat variables relate to patterns of genetic variation in 2 stonefly species, one from mainstem river habitats (Sweltsa coloradensis) and one from tributaries (Sweltsa fidelis) in 40 sites in northwest Montana, USA. We produced a draft genome assembly for S. coloradensis (N50 = 0.251 Mbp, BUSCO > 95% using insecta_ob9 reference genes). We genotyped 1930 SNPs in 372 individuals for S. coloradensis and 520 SNPs in 153 individuals for S. fidelis. We found higher genetic diversity for S. coloradensis compared to S. fidelis, but nearly identical genetic differentiation among sites within each species (both had global loci median FST = 0.000), despite differences in stream network location. For landscape genomics and testing for selection, we produced a less stringently filtered data set (3454 and 1070 SNPs for S. coloradensis and S. fidelis, respectively). Environmental variables (mean summer precipitation, slope, aspect, mean June stream temperature, land cover type) were correlated with 19 putative adaptive loci for S. coloradensis, but there was only one putative adaptive locus for S. fidelis (correlated with aspect). Interestingly, we also detected potential hybridization between multiple Sweltsa species which has never been previously detected. Studies like ours, that test for adaptive variation in multiple related species are needed to help assess landscape connectivity and the vulnerability of populations and communities to environmental change.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2019JG005476", "year": 2020, "title": "Synoptic meteorology explains temperate forest carbon uptake", "abstract": "While substantial attention has been paid to the effects of both global climate oscillations and local meteorological conditions on the interannual variability of ecosystem carbon exchange, the relationship between the interannual variability of synoptic meteorology and ecosystem carbon exchange has not been well studied. Here we use a clustering algorithm to identify a summertime cyclonic precipitation system northwest of the Great Lakes to determine (a) the association at a daily scale between the occurrence of this system and the local meteorology and net ecosystem exchange at three Great Lakes region forested eddy covariance sites and (b) the association between the seasonal prevalence of this system and the summertime net ecosystem exchange of these sites. We find that temperature, in addition to precipitation and cloud cover, is an important explanatory factor for the suppression of net ecosystem productivity that occurs during these cyclonic events in this region. In addition, the prevalence of this cyclonic system can explain a significant proportion of the interannual variability in summertime forest ecosystem exchange in this region. This explanatory power is not due to a simple accumulation of low-productivity days that cooccur with this meteorological event, but rather a broader association between the frequency of these events and several aspects of prevailing seasonal conditions. This work demonstrates the usefulness of conceptualizing meteorology in terms of synoptic systems for explaining the interannual variability of regional carbon fluxes.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1002/2017GL076630", "year": 2017, "title": "Atmospheric CO2 Observations Reveal Strong Correlation Between Regional Net Biospheric Carbon Uptake and Solar-Induced Chlorophyll Fluorescence", "abstract": "Recent studies have shown the promise of remotely sensed solar-induced chlorophyll fluorescence (SIF) in informing terrestrial carbon exchange, but analyses have been limited to either plot level ( 1 km2) or hemispheric/global ( 108 km2) scales due to the lack of a direct measure of carbon exchange at intermediate scales. Here we use a network of atmospheric CO2 observations over North America to explore the value of SIF for informing net ecosystem exchange (NEE) at regional scales. We find that SIF explains space-time NEE patterns at regional ( 100 km2) scales better than a variety of other vegetation and climate indicators. We further show that incorporating SIF into an atmospheric inversion leads to a spatial redistribution of NEE estimates over North America, with more uptake attributed to agricultural regions and less to needleleaf forests. Our results highlight the synergy of ground-based and spaceborne carbon cycle observations.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1111/1365-2656.13332", "year": 2021, "title": "Habitat loss and thermal tolerances influence the sensitivity of resident bird populations to winter weather at regional scales", "abstract": "Climate change and habitat loss pose the greatest contemporary threats to biodiversity, but their impacts on populations largely vary across species. These differential responses could be caused by complex interactions between landscape and climate change and species\u2011specific sensitivities. Understanding the factors that determine which species are most vulnerable to the synergistic effects of climate change and habitat loss is a high conservation priority. Here, we ask (a) whether and to what extent land cover moderates the impacts of winter weather on population dynamics of wintering birds, and (b) what role species' physiology might play in modifying their responses to changing weather conditions. To address these questions, we used thousands of observations collected by citizen scientists participating in Project FeederWatch to build dynamic occupancy models for 14 species of wintering birds. Populations of wintering birds were more dynamic, having higher rates of local extinction and colonization, in more forested landscapes during extreme cold\u2014presumably enabling them to better track resources. However, urban areas appeared to provide refuge for some species, as demonstrated by increased local colonization during the harshest winter weather. Lastly, we found that species\u2011specific differences in thermal tolerances strongly influenced occupancy dynamics such that species that are less cold\u2011tolerant were more likely to go locally extinct at colder sites and during colder periods throughout winter. Together, our results suggest that species that are less cold\u2011tolerant and populations occupying less forested landscapes are most vulnerable to extreme winter weather.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1029/2021GB007018", "year": 2022, "title": "Quantifying the role of seasonality in the marine carbon cycle feedback: An ESM2M case study", "abstract": "Observations and climate models indicate that changes in the seasonal amplitude of sea surface carbon dioxide partial pressure (A-pCO2) are underway and driven primarily by anthropogenic carbon (Cant) accumulation in the ocean. This occurs because pCO2 is more responsive to seasonal changes in physics (including warming) and biology in an ocean that contains more Cant. A-pCO2 changes have the potential to alter annual ocean carbon uptake and contribute to the overall marine carbon cycle feedback. Using the GFDL ESM2M Large Ensemble and a novel analysis framework, we quantify the influence of Cant accumulation on pCO2 seasonal cycles and sea-air CO2 fluxes. Specifically, we reconstruct alternative evolutions of the contemporary ocean state in which the sensitivity of pCO2 to seasonal thermal and biophysical variation is fixed at preindustrial levels, however the background, mean-state pCO2 fully responds to anthropogenic forcing. We find near-global A-pCO2 increases of >100% by 2100, under RCP8.5 forcing, with rising Cant accounting for \u223c100% of thermal and \u223c50% of nonthermal pCO2 component amplitude changes. The other \u223c50% of nonthermal pCO2 component changes are attributed to modeled changes in ocean physics and biology caused by climate change. Cant-induced A-pCO2 changes cause an 8.1 \u00b1 0.4% (ensemble mean \u00b1 1\u03c3) increase in ocean carbon uptake by 2100. The is because greater wintertime wind speeds enhance the impact of wintertime pCO2 changes, which work to increase the ocean carbon sink. Thus, the seasonal ocean carbon cycle feedback works in opposition to the larger, mean-state feedback that reduces ocean carbon uptake by \u223c60%.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1590/S2675-28242020068274", "year": 2020, "title": "Sub-lethal predatory shell damage does not affect physiology under high CO2 in the intertidal gastropod Tritia reticulata", "abstract": "Abstract Ocean acidification (OA) poses a major threat to marine animals, especially marine shelled invertebrates such as molluscs. Although many organisms are capable of compensating for the effects of OA, this can impose physiological costs and impact performance (e.g. through increased metabolism and decreased growth). Sublethal injuries on shells may provoke changes in energy allocation. Under acidified conditions, organisms would spend less energy on reproduction and somatic growth to repair the damage. Therefore, we analysed the physiological responses of the intertidal gastropod Tritia reticulata during shell regeneration under OA conditions. We simulated a sub-lethal predation event (a notch in the outer lip of the shell) and individuals were exposed to control (pH 8.08) and low pH scenarios (pH 7.88 and 7.65). After two months exposure, all individuals showed shell repair, with a full repair rate observed in 75% of individuals. Contrary to expectations, shell repair following sub-lethal damage and OA had no apparent impact on physiological state in terms of energy reserves (as measured by whole-animal Carbon/Nitrogen) or growth potential (as measured by whole-animal RNA:Protein and RNA:DNA ratios). As an intertidal organism, T. reticulata could be resilient to future global environmental change because of compensatory mechanisms that are inherent in intertidal animals, and may represent a robust species with which to study future scenarios of OA in temperate coastal ecosystems. However, unrestricted food availability during experiment could have played a role in the results and therefore food limitation should be considered in future studies regarding shell repair and metabolism under the effects of OA.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1016/J.SCITOTENV.2020.138501", "year": 2020, "title": "Changes in fish communities due to benthic habitat shifts under ocean acidification conditions", "abstract": "Ocean acidification will likely change the structure and function of coastal marine ecosystems over coming decades. Volcanic carbon dioxide seeps generate dissolved CO2 and pH gradients that provide realistic insights into the direction and magnitude of these changes. Here, we used fish and benthic community surveys to assess the spatio-temporal dynamics of fish community properties off CO2 seeps in Japan. Adding to previous evidence from ocean acidification ecosystem studies conducted elsewhere, our findings documented shifts from calcified to non-calcified habitats with reduced benthic complexity. In addition, we found that such habitat transition led to decreased diversity of associated fish and to selection of those fish species better adapted to simplified ecosystems dominated by algae. Our data suggest that near-future projected ocean acidification levels will oppose the ongoing range expansion of coral reef-associated fish due to global warming.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.1007/S10071-021-01587-0", "year": 2022, "title": "Bold and bright: shy and supple? The effect of habitat type on personality\u2013cognition covariance in the Aegean wall lizard (Podarcis erhardii)", "abstract": "Animals exhibit considerable and consistent among-individual variation in cognitive abilities, even within a population. Recent studies have attempted to address this variation using insights from the field of animal personality. Generally, it is predicted that animals with faster personalities (bolder, explorative, and neophilic) should exhibit faster but less flexible learning. However, the empirical evidence for a link between cognitive style and personality is mixed. One possible reason for such conflicting results may be that personalitycognition covariance changes along ecological conditions, a hypothesis that has rarely been investigated so far. In this study, we tested the effect of habitat complexity on multiple aspects of animal personality and cognition, and how this influenced their relationship, in five populations of the Aegean wall lizard (Podarcis erhardii). Overall, lizards from both habitat types did not differ in average levels of personality or cognition, with the exception that lizards from more complex habitats performed better on a spatial learning task. Nevertheless, we found an intricate interplay between ecology, cognition, and personality, as behavioral associations were often habitat- but also year-dependent. In general, behavioral covariance was either independent of habitat, or found exclusively in the simple, open environments. Our results highlight that valuable insights may be gained by taking ecological variation into account while studying the link between personality and cognition.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1111/DDI.13133", "year": 2020, "title": "Relationships between the distribution of wildlife and livestock diversity", "abstract": "AimWild biodiversity and agrobiodiversity are affected by challenges such as agricultural intensification. However, it is unknown whether or not both components of biodiversity respond similarly to environmental factors and to these challenges. Here, we examine the spatial relationships between the distributions of wild biodiversity and agrobiodiversity, to quantify how and where they covary across the geography.LocationMainland Spain, a European region that harbours high values of both wild and agro\u2011 biodiversity.MethodsWe used geographically weighted regression models to analyse the spatial variation in the relationships between the distribution of wild vertebrates and environmental and agrobiodiversity variables. We modelled the spatial gradients in species richness of native terrestrial vertebrates\u2014that is, specific groups of amphibians, reptiles, birds and mammals\u2014as a function of local livestock breed richness\u2014that is, bovine, ovine, caprine, asinine, equine and porcine\u2014climate variables and human footprint.ResultsWe found significant covariation between the distribution of native vertebrate species richness and climate, human footprint and livestock diversity. Overall, the association between species richness of the four wild terrestrial vertebrate groups and local livestock breed richness is positive across most of the studied area. However, local breed richness of cattle and sheep breed displays contrasting patterns, where cattle breeds associate positively to most wildlife vertebrates and sheep breeds show negative associations.Main conclusionWildlife diversity distributions are significantly associated with livestock agrobiodiversity. These spatial relationships are mediated by large\u2011scale environmental gradients. Since both, wildlife and livestock agrobiodiversity, tend to co\u2011occur spatially, future strategies for conservation in agricultural landscapes could benefit from integrated approaches.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1088/1748-9326/ABAB34", "year": 2020, "title": "The biophysical climate mitigation potential of boreal peatlands during", "abstract": "Peatlands and forests cover large areas of the boreal biome and are critical for global climate regulation. They also regulate regional climate through heat and water vapour exchange with the atmosphere. Understanding how land-atmosphere interactions in peatlands differ from forests may therefore be crucial for modelling boreal climate system dynamics and for assessing climate benefits of peatland conservation and restoration. To assess the biophysical impacts of peatlands and forests on peak growing season air temperature and humidity, we analysed surface energy fluxes and albedo from 35 peatlands and 37 evergreen needleleaf forests\u2014the dominant boreal forest type\u2014and simulated air temperature and vapour pressure deficit (VPD) over hypothetical homogeneous peatland and forest landscapes. We ran an evapotranspiration model using land surface parameters derived from energy flux observations and coupled an analytical solution for the surface energy balance to an atmospheric boundary layer (ABL) model. We found that peatlands, compared to forests, are characterized by higher growing season albedo, lower aerodynamic conductance, and higher surface conductance for an equivalent VPD. This combination of peatland surface properties results in a \u223c20% decrease in afternoon ABL height, a cooling (from 1.7 to 2.5 \u00b0C) in afternoon air temperatures, and a decrease in afternoon VPD (from 0.4 to 0.7 kPa) for peatland landscapes compared to forest landscapes. These biophysical climate impacts of peatlands are most pronounced at lower latitudes (\u223c45\u00b0N) and decrease toward the northern limit of the boreal biome (\u223c70\u00b0N). Thus, boreal peatlands have the potential to mitigate the effect of regional climate warming during the growing season. The biophysical climate mitigation potential of peatlands needs to be accounted for when projecting the future climate of the boreal biome, when assessing the climate benefits of conserving pristine boreal peatlands, and when restoring peatlands that have experienced peatland drainage and mining.", "labels": [ { "id": 6, "name": "Ecosystems" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.7717/PEERJ.12296", "year": 2021, "title": "Differences in insectivore bird diets in coffee agroecosystems driven by", "abstract": "Neotropical shade-grown coffee systems are renowned for their potential to conserve avian biodiversity. Yet, little is known about food resources consumed by insectivorous birds in these systems, the extent of resource competition between resident and migratory birds, or how management of shade trees might influence diet selection. We identified arthropods in stomach contents from obligate and generalist insectivorous birds captured in mist-nets at five coffee farms in Chiapas, Mexico between 20012003. Overall stomach contents from 938 individuals revealed dietary differences resulting from changes in seasons, years, and foraging guilds. Of four species sampled across all management systems, Yellow-green Vireo (\r\n Vireo flavoviridis\r\n ) prey differed depending on coffee shade management, consuming more ants in shaded monoculture than polyculture systems. Diets of obligate and generalist resident insectivores were 72% dissimilar with obligate insectivores consuming more Coleoptera and Araneae, and generalist insectivores consuming more Formicidae and other Hymenoptera. This suggests that obligate insectivores target more specialized prey whereas generalist insectivores rely on less favorable, chemically-defended prey found in clumped distributions. Our dataset provides important natural history data for many Nearctic-Neotropical migrants such as Tennessee Warbler (\r\n Leiothlypis peregrina; N = 163\r\n ), Nashville Warbler (\r\n Leiothlypis ruficapilla; N = 69\r\n ), and Swainsons Thrush (\r\n Catharus ustulatus; N = 68\r\n ) and tropical residents including Red-legged Honeycreepers (\r\n Cyanerpes cyaneus; N = 70\r\n ) and Rufous-capped Warblers (\r\n Basileuterus rufifrons; N = 56\r\n ). With declining arthropod populations worldwide, understanding the ecological interactions between obligate and generalist avian insectivores gives researchers the tools to evaluate community stability and inform conservation efforts.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.4003/006.036.0206", "year": 2018, "title": "Reproductive cycle of Donax punctatostriatus (Hanley, 1843)(Bivalvia: Donacidae) in a sandy beach of Sinaloa, Mexico", "abstract": "The reproductive cycle, stages of gonadal development, and minimum size of sexual maturity are described for a population of the clam Donax punctatostriatus Hanley, 1843 from a sandy beach in southern Sinaloa, Mexico. A total of 880 clams were collected from January 2009 to June 2010; 3.2% were sexually undifferentiated and 1.4% had the trematode parasite Postmonorchis sp, in the gonadal tissue. The total length of the clams ranged from 3.525.64 mm ( = 13.51, S.D. = 4.47 mm). The sexual proportion did not differ significantly from 1:1 (p > 0.05). The minimum size at sexual maturity (L50) was L50 = 12.03 mm. The gametogenic cycle comprise six stages of gonadal development (0-V). The population is reproductively active throughout the year and spawning is continuous, with three major peaks in April, July and September 2009. In March, when the water temperature was between 2123 C, most individuals were in stage I. This period is characterized by a rapid maturation of gametes. At the end of October and during November, when water temperature was warmer (2528 C), 50% of the individuals were in stage V (spent). Recruitment was more intense from July to October of 2009, when the highest temperatures of the year were recorded (2831 C). Photoperiod and the proportion of mature individuals of both sexes were significantly correlated (Pearson's correlation value = 0.62; p < 0.05). Since this clam is a potential resource for human consumption, the information here presented may contribute to a better management and use of their populations in the Mexican Pacific.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.OCEANO.2016.12.002", "year": 2017, "title": "Spatio-temporal variability of the phytoplankton biomass in the Levantine basin between 2002 and 2015 using MODIS products", "abstract": "The Levantine basin in the Eastern Mediterranean Sea is subject to spatial and seasonal variations in primary production and physical-chemical properties both on a short and long-term basis. In this study, the monthly means of daily MODIS product images were averaged between 2002 and 2015, and used to characterize the phytoplankton blooms in different bioregions of the Levantine basin. The selected products were the sea surface temperature (SST), the chlorophyll-a concentration (Chl-a), the diffuse attenuation coefficient for downwelling irradiance at 490nm (Kd_490) and the colored dissolved organic matter index (CDOM_index). Our results showed that phytoplankton blooms were spatially and temporally variable. They occurred in late autumn at the Nile Delta, in early spring and late summer at the eastern coastline, and in spring at the northeastern coastline. The northern coastline and the open water had a common bloom occurring in winter. The Nile Delta was found to be the most productive area of the Levantine basin showing high Chl-a. Kd_490 and Chl-a present a parallel co-variation indicating a dominance of Case 1 waters in the Levantine basin. The CDOM_index shows a phase shift with the Chl-a fluctuation. A strong inverse correlation was observed between both Chl-a and CDOM_index with SST, connoting an indirect relation represented by a depression of CDOM in summer by photobleaching, and a suppression of the chlorophyll-a concentration due to water stratification, together with nutrient stress. An overestimation of the Chl-a values had been signaled by the use of the CDOM_index, suggesting a correction plan in a latter study.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1098/RSPB.2018.0176", "year": 2018, "title": "Hot temperatures during the dry season reduce survival of a resident tropical bird", "abstract": "Understanding how climate change will shape species distributions in the future requires a functional understanding of the demographic responses of animals to their environment. For birds, most of our knowledge of how climate influences population vital rates stems from research in temperate environments, even though most of Earth's avian diversity is concentrated in the tropics. We evaluated effects of Southern Oscillation Index (SOI) and local temperature and rainfall at multiple temporal scales on sex-specific survival of a resident tropical bird, the rufous-and-white wren Thryophilus rufalbus, studied over 15 years in the dry forests of northwestern Costa Rica. We found that annual apparent survival of males was 8% higher than females, more variable over time, and responded more strongly to environmental variation than female survival, which did not vary strongly with SOI or local weather. For males, mean and maximum local temperatures were better predictors of survival than either rainfall or SOI, with high temperatures during the dry season and early wet season negatively influencing survival. These results suggest that, even for species adapted to hot environments, further temperature increases may threaten the persistence of local populations in the absence of distributional shifts.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1088/1748-9326/AC7B38", "year": 2022, "title": "Data-driven quantification of nitrogen enrichment impact on Northern Hemisphere plant biomass", "abstract": "The production of anthropogenic reactive nitrogen (N) has grown so much in the last century that quantifying the effect of N enrichment on plant growth has become a central question for carbon (C) cycle research. Numerous field experiments generally found that N enrichment increased site-scale plant biomass, although the magnitude of the response and sign varied across experiments. We quantified the response of terrestrial natural vegetation biomass to N enrichment in the Northern Hemisphere (>30N) by scaling up data from 773 field observations (142 sites) of the response of biomass to N enrichment using machine-learning algorithms. N enrichment had a significant and nonlinear effect on aboveground biomass, but a marginal effect on belowground biomass. The most influential variables on the aboveground biomass response were the amount of N applied, mean biomass before the experiment, the treatment duration and soil phosphorus availability. From the machine learning models, we found that N enrichment due to increased atmospheric N deposition during 1993-2010 has enhanced total biomass by 1.10.3 Pg C, in absence of losses from harvest and disturbances. The largest effect of N enrichment on plant growth occurred in northeastern Asia, where N deposition markedly increased. These estimates were similar to the range of values provided by state-of-the-art C-N ecosystem process models. This work provides data-driven insights into hemisphere-scale N enrichment effect on plant biomass growth, which allows to constrain the terrestrial ecosystem process model used to predict future terrestrial C storage.", "labels": [ { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/ACP-10-3965-2010", "year": 2010, "title": "Greenhouse gas relationships in the Indian summer monsoon plume measured by the CARIBIC passenger aircraft", "abstract": "Abstract. During the Indian summer monsoon period 2008, regular measurement flights were performed by the CARIBIC aircraft between Germany and India. Measurements included whole air sampling and subsequent analysis for greenhouse gases (CH4, CO2, N2O, SF6) and in-situ measurements of CO, O3, and H2O. For all these tracers a distinct monsoon signature was observed in the longitude range 5080 E south of 40 N at flight altitudes 812.5 km. The formation of a monsoon plume with enhanced mixing ratios was observed for CH4, N2O, SF6, CO and H2O. The plume began to develop in May and persisted through September, and maximum mixing ratios and maximum spatial extension of the plume were observed in August. For CO2 and O3 a minimum was observed. The amplitude of the CO2 seasonal cycle was larger than at comparable latitudes outside the monsoon region, and the CO2 spring maximum was observed with a delay of one month. Different tracer relationships show strong spatial variations across the plume. The comparison with NOAA ground station data shows a clear enhancement for CH4, N2O, SF6 and CO and a decrease in CO2 mixing ratios. Assuming seasonally invariant SF6 emissions based on the EDGAR 4.0 inventory, monthly emissions were estimated for the period JuneSeptember for CH4, N2O, and CO, and the CO2 uptake was estimated. While for N2O an emission decrease during the monsoon period was derived, emissions of CH4 were highest in September indicating a different seasonal cycle of emissions. Net CO2 uptake by the vegetation was largest in September.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1088/1755-1315/606/1/012042", "year": 2020, "title": "Atmospheric composition study based on ship measurements in the Russian Arctic seas in summer 2019", "abstract": "Abstract\r\n \r\n We present observation results of methane (CH\r\n 4\r\n ), its isotopic signature (\r\n 13\r\n C\r\n CH4\r\n ) and carbon dioxide (CO\r\n 2\r\n ) surface concentrations, made aboard the research vessel (R/V) Akademik Mstislav Keldysh in the Russian Arctic seas in summer 2019. The main goal of the study is to determine the possible sources of methane. As a result of the study, localized areas with an increased methane concentration (up to 2092 ppb) in the surface layer are identified. It may be related to the advection of water masses rich in organic matter from the Ob and Yenisei Rivers. In addition, increased methane concentrations (up to 2010 ppb) are observed in the Kara Sea near the Yamal Peninsula, where gas deposits are concentrated, and active methane emissions from wetland ecosystems are noted. We conclude that the average concentration of methane in surface air in the Arctic seas is determined mainly by large-scale transport of air masses.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1029/2020EF001938", "year": 2021, "title": "Global CO2 Consumption by Silicate Rock Chemical Weathering: Its Past and Future", "abstract": "Silicate rock weathering maintains a stable and long term absorption of CO2. However, the magnitude, spatial pattern, and evolution characteristics of global silicate rock weathering carbon sink (SCS) remain unclear. To solve this problem, based on high precision hydrometeorological data (1996-2017) and CMIP5 data (2041-2060), using the Celine model, we calculated the global silicate rock weathering carbon sink flux (SCSF) magnitude and spatio temporal distribution for 1996-2017. We also predicted the SCSF under two future greenhouse gas emission scenarios (RCP 4.5 and RCP 8.5). Then, we produced a spatial data set (0.5 \u00d7 0.5) of global SCSF from 1996 to 2017 and found that the global average annual SCSF was 1.67 t/km2/yr, and the SCS was 127.11 Tg/yr. In particular, Brazil's silicate rock contribution accounts for nearly a quarter of the global SCS (24.41%). Although the GEM CO2 model is now widely used, the SCSF, without considering the temperature, may be overestimated by 5.4%, and the maximum contribution of temperature to it can reach 240 kg/km2/yr. Moreover, the global SCS is now showing a downward trend, but the global emission of greenhouse gases in the future (2041-2060) will continue to increase the carbon sink capacity (23.8%) due to temperature changes. In summary, we have produced a set of high resolution spatiotemporal data of the past and the future. The above results fill up the large scale data gap of SCSF and provide a scientific basis for quantitatively assessing the impact of climate change on SCS.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/S41467-020-20871-0", "year": 2021, "title": "Under-reporting of greenhouse gas emissions in US cities", "abstract": "Cities dominate greenhouse gas emissions. Many have generated self-reported emission inventories, but their value to emissions mitigation depends on their accuracy, which remains untested. Here, we compare self-reported inventories from 48 US cities to independent estimates from the Vulcan carbon dioxide emissions data product, which is consistent with atmospheric measurements. We found that cities under-report their own greenhouse gas emissions, on average, by 18.3% (range: 145.5% to +63.5%) a difference which if extrapolated to all U.S. cities, exceeds Californias total emissions by 23.5%. Differences arise because city inventories omit particular fuels and source types and estimate transportation emissions differently. These results raise concerns about self-reported inventories in planning or assessing emissions, and warrant consideration of the new urban greenhouse gas information system recently developed by the scientific community.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/J.RSER.2022.112670", "year": 2022, "title": "Assuring the integrity of offshore carbon dioxide storage", "abstract": "Carbon capture and storage is a key mitigation strategy proposed for keeping the global temperature rise below 1.5 C. Offshore storage can provide up to 13% of the global CO2 reduction required to achieve the Intergovernmental Panel on Climate Change goals. The public must be assured that potential leakages from storage reservoirs can be detected and that therefore the CO2 is safely contained. We conducted a controlled release of 675 kg CO2 within sediments at 120 m water depth, to simulate a leak and test novel detection, quantification and attribution approaches. We show that even at a very low release rate (6 kg day1), CO2 can be detected within sediments and in the water column. Alongside detection we show the fluxes of both dissolved and gaseous CO2 can be quantified. The CO2 source was verified using natural and added tracers. The experiment demonstrates that existing technologies and techniques can detect, attribute and quantify any escape of CO2 from sub-seabed reservoirs as required for public assurance, regulatory oversight and emissions trading schemes.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.5194/BG-12-323-2015", "year": 2015, "title": "Atmospheric inversion of surface carbon flux with consideration of the spatial distribution of US crop production and consumption", "abstract": "Abstract. In order to improve quantification of the spatial distribution of carbon sinks and sources in the conterminous US, we conduct a nested global atmospheric inversion with detailed spatial information on crop production and consumption. County-level cropland net primary productivity, harvested biomass, soil carbon change, and human and livestock consumption data over the conterminous US are used for this purpose. Time-dependent Bayesian synthesis inversions are conducted based on CO2 observations at 210 stations to infer CO2 fluxes globally at monthly time steps with a nested focus on 30 regions in North America. Prior land surface carbon fluxes are first generated using a biospheric model, and the inversions are constrained using prior fluxes with and without adjustments for crop production and consumption over the 20022007 period. After these adjustments, the inverted regional carbon sink in the US Midwest increases from 0.25 0.03 to 0.42 0.13 Pg C yr1, whereas the large sink in the US southeast forest region is weakened from 0.41 0.12 to 0.29 0.12 Pg C yr1. These adjustments also reduce the inverted sink in the west region from 0.066 0.04 to 0.040 0.02 Pg C yr1 because of high crop consumption and respiration by humans and livestock. The general pattern of sink increases in crop production areas and sink decreases (or source increases) in crop consumption areas highlights the importance of considering the lateral carbon transfer in crop products in atmospheric inverse modeling, which provides a reliable atmospheric perspective of the overall carbon balance at the continental scale but is unreliable for separating fluxes from different ecosystems.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.5194/ACP-18-17207-2018", "year": 2018, "title": "Methane at Svalbard and over the European Arctic ocean", "abstract": "Abstract. Methane (CH4) is a powerful greenhouse gas. Its atmospheric mixing ratios have been increasing since 2005. Therefore, quantification of CH4 sources is essential for effective climate change mitigation. Here we report observations of the CH4 mixing ratios measured at the Zeppelin Observatory (Svalbard) in the Arctic and aboard the research vessel (RV) Helmer Hanssen over the Arctic Ocean from June 2014 to December 2016, as well as the long-term CH4 trend measured at the Zeppelin Observatory from 2001 to 2017. We investigated areas over the European Arctic Ocean to identify possible hotspot regions emitting CH4 from the ocean to the atmosphere, and used state-of-the-art modelling (FLEXPART) combined with updated emission inventories to identify CH4 sources. Furthermore, we collected air samples in the region as well as samples of gas hydrates, obtained from the sea floor, which we analysed using a new technique whereby hydrate gases are sampled directly into evacuated canisters. Using this new methodology, we evaluated the suitability of ethane and isotopic signatures (13C in CH4) as tracers for ocean-to-atmosphere CH4 emission. We found that the average methane / light hydrocarbon (ethane and propane) ratio is an order of magnitude higher for the same sediment samples using our new methodology compared to previously reported values, 2379.95 vs. 460.06, respectively. Meanwhile, we show that the mean atmospheric CH4 mixing ratio in the Arctic increased by 5.90.38 parts per billion by volume (ppb) per year (yr1) from 2001 to 2017 and 8 pbb yr1 since 2008, similar to the global trend of 78 ppb yr1. Most large excursions from the baseline CH4 mixing ratio over the European Arctic Ocean are due to long-range transport from land-based sources, lending confidence to the present inventories for high-latitude CH4 emissions. However, we also identify a potential hotspot region with oceanatmosphere CH4 flux north of Svalbard (80.4 N, 12.8 E) of up to 26 nmol m2 s1 from a large mixing ratio increase at the location of 30 ppb. Since this flux is consistent with previous constraints (both spatially and temporally), there is no evidence that the area of interest north of Svalbard is unique in the context of the wider Arctic. Rather, because the meteorology at the time of the observation was unique in the context of the measurement time series, we obtained over the short course of the episode measurements highly sensitive to emissions over an active seep site, without sensitivity to land-based emissions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.4995/RAET.2022.15594", "year": 2022, "title": "Bottom-up estimates of atmospheric emissions of CO2, NO2, CO, NH3, and Black Carbon, generated by biomass burning in the north of South America", "abstract": "Biomass burning is an important source of greenhouse gases (GHG) and air pollutants (AP) in developing countries. In this research, a bottom-up method was implemented for the estimation of emissions, emphasizing the validation process of aerial biomass products (AGB), which it has not been sufficiently approached from the point of view of the quantification of emissions. The most recent results on the validation of burned area (AQ) products and the analysis of uncertainty were also incorporated into the process of estimating the emissions of gases that directly or indirectly promote the greenhouse effect, such as CO2, NO2, CO, NH3, and Black Carbon (BC). In total, 87.60 Mha were burned in the region between 2001 and 2016, represented in a 57% by pasture lands a 23% by savannas, an 8% by savanna woodlands, an 8% by mixed soils with crops and natural vegetation, a 3% by evergreen broadleaf forests, and a 1 % in the region s remaining types of land cover. With 35480 reference polygons, a model based on the uncertainty of AQ was generated, which served to find the calibration factor of the FireCCI5.0 in all the studied species. The total emissions (minimum and maximum) and the average of the same in the study period were the following: 1760 Tg CO2 (765.07-2552.88; average 110 Tg), 68.12 Tg of CO (27.11-98.87; average 4.26 Tg), 3.05 Tg of NO2 (1.27-4.40; average 0.19 Tg), 0.76 Tg of NH3 (0.33-1.12; average 0.05 Tg), and 0.44 Tg of Black Carbon (0.015-0.64; average 0.03 Tg).", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1038/S41597-019-0119-1", "year": 2019, "title": "Six years of ecosystem-atmosphere greenhouse gas fluxes measured in a sub-boreal forest", "abstract": "Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) are the greenhouse gases largely responsible for anthropogenic climate change. Natural plant and microbial metabolic processes play a major role in the global atmospheric budget of each. We have been studying ecosystem-atmosphere trace gas exchange at a sub-boreal forest in the northeastern United States for over two decades. Historically our emphasis was on turbulent fluxes of CO2 and water vapor. In 2012 we embarked on an expanded campaign to also measure CH4 and N2O. Here we present continuous tower-based measurements of the ecosystem-atmosphere exchange of CO2 and CH4, recorded over the period 20122018 and reported at a 30-minute time step. Additionally, we describe a five-year (20122016) dataset of chamber-based measurements of soil fluxes of CO2, CH4, and N2O (20132016 only), conducted each year from May to November. These data can be used for process studies, for biogeochemical and land surface model validation and benchmarking, and for regional-to-global upscaling and budgeting analyses.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.3390/RS13112037", "year": 2021, "title": "Sub-Daily Natural CO2 Flux Simulation Based on Satellite Data: Diurnal", "abstract": "During the last decade, advances in the remote sensing of greenhouse gas (GHG) concentrations by the Greenhouse Gases Observing SATellite-1 (GOSAT-1), GOSAT-2, and Orbiting Carbon Observatory-2 (OCO-2) have produced finer-resolution atmospheric carbon dioxide (CO2) datasets. These data are applicable for a top-down approach towards the verification of anthropogenic CO2 emissions from megacities and updating of the inventory. However, great uncertainties regarding natural CO2 flux estimates remain when back-casting CO2 emissions from concentration data, making accurate disaggregation of urban CO2 sources difficult. For this study, we used Moderate Resolution Imaging Spectroradiometer (MODIS) land products, meso-scale meteorological data, SoilGrids250 m soil profile data, and sub-daily soil moisture datasets to calculate hourly photosynthetic CO2 uptake and biogenic CO2 emissions with 500 m resolution for the Kanto Plain, Japan, at the center of which is the Tokyo metropolis. Our hourly integrated modeling results obtained for the period 20102018 suggest that, collectively, the vegetated land within the Greater Tokyo Area served as a daytime carbon sink year-round, where the hourly integrated net atmospheric CO2 removal was up to 14.15 4.24% of hourly integrated anthropogenic emissions in winter and up to 55.42 10.39% in summer. At night, plants and soil in the Greater Tokyo Area were natural carbon sources, with hourly integrated biogenic CO2 emissions equivalent to 2.27 0.11%4.97 1.17% of the anthropogenic emissions in winter and 13.71 2.44%23.62 3.13% in summer. Between January and July, the hourly integrated biogenic CO2 emissions of the Greater Tokyo Area increased sixfold, whereas the amplitude of the midday hourly integrated photosynthetic CO2 uptake was enhanced by nearly five times and could offset up to 79.04 12.31% of the hourly integrated anthropogenic CO2 emissions in summer. The gridded hourly photosynthetic CO2 uptake and biogenic respiration estimates not only provide reference data for the estimation of total natural CO2 removal in our study area, but also supply prior input values for the disaggregation of anthropogenic CO2 emissions and biogenic CO2 fluxes when applying top-down approaches to update the megacitys CO2 emissions inventory. The latter contribution allows unprecedented amounts of GOSAT and ground measurement data regarding CO2 concentration to be analyzed in inverse modeling of anthropogenic CO2 emissions from Tokyo and the Kanto Plain.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1029/2022JG006895", "year": 2022, "title": "Quantifying the Natural Climate Solution Potential of Agricultural Systems by Combining Eddy Covariance and Remote Sensing", "abstract": "Livestock agriculture accounts for \u223c15% of global anthropogenic greenhouse gas (GHG) emissions. Recently, natural climate solutions (NCS) have been identified to mitigate farm-scale GHG emissions. Nevertheless, their impacts are difficult to quantify due to farm spatial heterogeneity and effort required to measure changes in carbon stocks. Remote sensing (RS) models are difficult to parameterize for heterogeneous agricultural landscapes. Eddy covariance (EC) in combination with novel techniques that quantitatively match source area variations could help update such vegetation-specific parameters while accounting for pronounced heterogeneity. We evaluate a plant physiological parameter, the maximum quantum yield (MQY), which is commonly used to calculate gross and net primary productivity in RS applications. RS models often rely on spatially invariable MQY, which leads to inconsistencies between RS and EC models. We evaluate if EC data improve RS models by updating crop specific MQYs to quantify agricultural GHG mitigation potentials. We assessed how farm harvest compared to annual sums of (a) RS without improvements, (b) EC results, and (c) EC-RS models. We then estimated emissions to calculate the annual GHG balance, including mitigation through plant carbon uptake. Our results indicate that EC-RS models significantly improved the prediction of crop yields. The EC model captures diurnal variations in carbon dynamics in contrast to RS models based on input limitations. A net zero GHG balance indicated that perennial vegetation mitigated over 60% of emissions while comprising 40% of the landscape. We conclude that the combination of RS and EC can improve the quantification of NCS in agroecosystems.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" } ] }, { "doi": "10.1038/S41467-022-30456-8", "year": 2022, "title": "Reactive halogens increase the global methane lifetime and radiative forcing in the 21st century", "abstract": "CH4 is the most abundant reactive greenhouse gas and a complete understanding of its atmospheric fate is needed to formulate mitigation policies. Current chemistry-climate models tend to underestimate the lifetime of CH4, suggesting uncertainties in its sources and sinks. Reactive halogens substantially perturb the budget of tropospheric OH, the main CH4 loss. However, such an effect of atmospheric halogens is not considered in existing climate projections of CH4 burden and radiative forcing. Here, we demonstrate that reactive halogen chemistry increases the global CH4 lifetime by 69% during the 21st century. This effect arises from significant halogen-mediated decrease, mainly by iodine and bromine, in OH-driven CH4 loss that surpasses the direct Cl-induced CH4 sink. This increase in CH4 lifetime helps to reduce the gap between models and observations and results in a greater burden and radiative forcing during this century. The increase in CH4 burden due to halogens (up to 700 Tg or 8% by 2100) is equivalent to the observed atmospheric CH4 growth during the last three to four decades. Notably, the halogen-driven enhancement in CH4 radiative forcing is 0.05 W/m2 at present and is projected to increase in the future (0.06 W/m2 by 2100); such enhancement equals ~10% of present-day CH4 radiative forcing and one-third of N2O radiative forcing, the third-largest well-mixed greenhouse gas. Both direct (Cl-driven) and indirect (via OH) impacts of halogens should be included in future CH4 projections.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1016/B978-0-12-814952-2.00001-0", "year": 2022, "title": "Greenhouse gas balances in coastal ecosystems: Current challenges in \u201cblue carbon\u201d estimation and significance to national greenhouse gas inventories", "abstract": "Coastal wetlands are defined herein as inundated, vegetated ecosystems with hydrology, and biogeochemistry influenced by sea levels, at timescales of tides to millennia. Coastal wetlands are necessary components of global greenhouse gas estimation and scenario modeling, both for continental and oceanic mass balances. The carbon pools and fluxes on coastal lands, especially those influenced by tidal drivers and sea level rise, are distinct in their magnitude, rates, and uncertainties. We describe herein the pathways taken for a US scale estimation of blue carbon based on annual timesteps and bottom-up modeling, as appropriate for the first effort to include coastal wetlands in the Intergovernmental Panel on Climate Change (IPCC) guidelines for a National Greenhouse Gas Inventory (NGGI). As such, we summarize multiple efforts to reconcile mapping, modeling, and measurement issues and we report the assumptions we made based on data availability. Provided as requested feedback to the IPCC. Subsidiary Body for Scientific and Technological Advice (SBSTA) evaluation of guidance criteria, these analyses synergistically point scientists, practitioners, and policy makers toward the greatest uncertainties to address in future assessments: coastal wetland methane emissions and carbon dioxide emissions associated with the fate of eroded soil. This is a story of what was learned in the 20142018 NASA Carbon Monitoring System project (https://carbon.nasa.gov/cgi-bin/cms_projects.pl), how it informs good practice (IPCC 2006) in reporting coastal wetland emissions and removals, and where it points scientifically toward data needs at different temporal and spatial scales.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.5194/TC-16-3949-2022", "year": 2022, "title": "Quantifying the effects of background concentrations of crude oil pollution on sea ice albedo", "abstract": "Abstract. Sea ice albedo plays an important role in modulating the climate of Earth and is affected by low background concentrations of oil droplets within the ice matrix that absorb solar radiation. In this study, the albedo response of three different types of bare sea ice (melting, first-year, and multi-year sea ice) are calculated at increasing mass ratios (01000 ng g1) of crude oil by using a coupled atmospheresea ice radiative-transfer model (TUV-snow; Tropospheric UltravioletVisible) over the optical wavelengths 400700 nm. The different types of quasi-infinite-thickness sea ice exhibit different albedo responses to oil pollution, with a 1000 ng g1 mass ratio of oil causing a decrease to 70.9 % in multi-year sea ice, 47.2 % in first-year sea ice, and 22.1 % in melting sea ice relative to the unpolluted albedo at a wavelength of 400 nm. The thickness of the sea ice is also an important factor, with realistic-thickness sea ices exhibiting similar results, albeit with a weaker albedo response for multi-year sea ice to 75.3 %, first-year sea ice to 66.3 %, and melting sea ice to 35.9 %. The type of oil also significantly affects the response of sea ice albedo, with a relatively opaque and heavy crude oil (Romashkino oil) causing a significantly larger decrease in sea ice albedo than a relatively transparent light crude oil (Petrobaltic oil). The size of the oil droplets polluting the oil also plays a minor role in the albedo response, with weathered submicrometre droplets (0.050.5 m radius) of Romashkino oil being the most absorbing across the optical wavelengths considered. Therefore, the work presented here demonstrates that low background concentrations of small submicrometre- to micrometre-sized oil droplets have a significant effect on the albedo of bare sea ice. All three types of sea ice are sensitive to oil pollution; however, first-year sea ice and particularly melting sea ice are very sensitive to oil pollution.", "labels": [ { "id": 8, "name": "Environmental Impacts" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1007/S12040-019-1305-4", "year": 2020, "title": "Eddy covariance measurements of CO2 exchange from agro-ecosystems located in subtropical (India) and boreal (Finland) climatic conditions", "abstract": "Climate impacts agriculture in various complex ways at different levels and scales depending on the local natural crop growth limitations. Our objective in this study, therefore, is to understand how different is the atmospherebiosphere exchange of CO2 under contrasting subtropical and boreal agricultural (an oilseed crop and a bioenergy crop, respectively) climates. The oilseed crop in subtropical climate continued to uptake CO2 from the atmosphere throughout the year, with maximum uptake occurring in the monsoon season, and drastically reduced uptake during drought. The boreal ecosystem, on the other hand, was a sustained, small source of CO2 to the atmosphere during the snow-covered winter season. Higher rates of CO2 uptake were observed owing to greater day-length in the growing season in the boreal ecosystem. The optimal temperature for photosynthesis by the subtropical ecosystem was close to the regional normal mean temperature. An enhanced photosynthetic response to the incident radiation was found for the boreal ecosystem implying the bioenergy crop to be more efficient than the oilseed crop in utilizing the available light. This comparison of the CO2 exchange patterns will help strategising the carbon management under different climatic conditions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 0, "name": "Agriculture" }, { "id": 6, "name": "Ecosystems" } ] }, { "doi": "10.1016/J.SCITOTENV.2018.06.151", "year": 2018, "title": "Carbon dioxide, methane and nitrous oxide emissions from the human-impacted Seine watershed in France", "abstract": "Greenhouse gas (GHG) emissions from rivers and lakes have been shown to contribute significantly to global carbon and nitrogen cycling. In temperate and human-impacted regions, simultaneous carbon dioxide, methane and nitrous oxide emissions from aquatic systems are poorly documented. We estimated carbon dioxide (CO2) concentrations in the Seine hydrosystem (71,730 km2, France) using direct measurements, and calculations of CO2 partial pressures from 14 field campaigns conducted between 2010 and 2017, and compared them to methane (CH4) and nitrous oxide (N2O) concentrations. In the main stem of the Seine River, CO2 showed the same spatial gradient as N2O and CH4 with peaks in concentration downstream from the arrival of effluents from wastewater treatment plants enriched in organic matter, thus favoring mineralization. It is likely that high CO2 concentrations upstream were due to organic carbon inputs from soils and enriched CO2 groundwater discharges, whereas high N2O and CH4 upstream values were likely due to denitrification in riparian wet areas and anoxic decomposition of organic matter-rich wetlands, respectively. In addition, seasonal variations in all three GHGs were observed with higher concentrations in summer when higher temperatures promote mineralization and low water reduces the dilution of organic matter mainly originating from WWTP effluents. GHG emissions were calculated and compared with agricultural and nonagricultural (urban, transport) fluxes in the basin. In the Seine River network, CO2 emissions dominated riverine GHG emissions, reaching 95.3%, while N2O and CH4 emissions accounted for 4.4% and 0.3%, respectively. These indirect emissions from the hydrosystem were estimated to account for 3.7% of the total GHG emissions from the basin that amounted to 61,284 Gg CO2eq yr1. Comparatively, direct agricultural and nonagricultural GHG emissions were estimated at 23.3% and 73.0%., respectively.", "labels": [ { "id": 10, "name": "Greenhouse Gases" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.5194/ACP-18-185-2018", "year": 2018, "title": "Estimating regional-scale methane flux and budgets using CARVE aircraft measurements over Alaska", "abstract": "Abstract. Methane (CH4) is the second most important greenhouse gas but its emissions from northern regions are still poorly constrained. In this study, we analyze a subset of in situ CH4 aircraft observations made over Alaska during the growing seasons of 20122014 as part of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE). Net surface CH4 fluxes are estimated using a Lagrangian particle dispersion model which quantitatively links surface emissions from Alaska and the western Yukon with observations of enhanced CH4 in the mixed layer. We estimate that between May and September, net CH4 emissions from the region of interest were 2.2 0.5 Tg, 1.9 0.4 Tg, and 2.3 0.6 Tg of CH4 for 2012, 2013, and 2014, respectively. If emissions are only attributed to two biogenic eco-regions within our domain, then tundra regions were the predominant source, accounting for over half of the overall budget despite only representing 18 % of the total surface area. Boreal regions, which cover a large part of the study region, accounted for the remainder of the emissions. Simple multiple linear regression analysis revealed that, overall, CH4 fluxes were largely driven by soil temperature and elevation. In regions specifically dominated by wetlands, soil temperature and moisture at 10 cm depth were important explanatory variables while in regions that were not wetlands, soil temperature and moisture at 40 cm depth were more important, suggesting deeper methanogenesis in drier soils. Although similar environmental drivers have been found in the past to control CH4 emissions at local scales, this study shows that they can be used to generate a statistical model to estimate the regional-scale net CH4 budget.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.1038/S43247-021-00312-6", "year": 2021, "title": "A Bayesian framework for deriving sector-based methane emissions from top-down fluxes", "abstract": "Atmospheric methane observations are used to test methane emission inventories as the sum of emissions should correspond to observed methane concentrations. Typically, concentrations are inversely projected to a net flux through an atmospheric chemistry-transport model. Current methods to partition net fluxes to underlying sector-based emissions often scale fluxes based on the relative weight of sectors in a prior inventory. However, this approach imposes correlation between emission sectors which may not exist. Here we present a Bayesian optimal estimation method that projects inverse methane fluxes directly to emission sectors while accounting uncertainty structure and spatial resolution of prior fluxes and emissions. We apply this method to satellite-derived fluxes over the U.S. and at higher resolution over the Permian Basin to demonstrate that we can characterize a sector-based emission budget. This approach provides more robust comparisons between different top-down estimates, critical for assessing the efficacy of policies intended to reduce emissions.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.2151/SOLA.2016-037", "year": 2016, "title": "The Effect of GOSAT Observations on Estimates of Net CO2 Flux in Semi-Arid Regions of the Southern Hemisphere", "abstract": "Greenhouse gases Observing SATellite (GOSAT) is the operational satellite dedicated to atmospheric CO2 observations. Assimilation of data provided by GOSAT is expected to yield reliable CO2 fluxes in semi-arid regions because of frequent observations owing to clear skies. Here we estimated net CO2 flux over semi-arid regions of the Southern Hemisphere using the GOSAT column averaged CO2 (XCO2) and surface CO2 measurements. Assimilation of GOSAT XCO2 indicated that semi-arid regions are integral components of recent terrestrial CO2 uptake, accounting for 44% globally. Compared with estimates assimilated from surface measurements, estimates by GOSAT XCO2 suggest a 50% reduction in the semi-arid CO2 uptake, amounting to 1.1 Pg C yr1. Significant estimation differences occurred for South America and South Africa, where the GOSAT makes frequent measurements but where surface CO2 measurements are limited. In comparison, the two estimates varied less in Australia, where more surface measurements are available. These results suggest that GOSAT XCO2 is effective at regulating excess estimates of semi-arid CO2 uptake in regions that are less constrained by surface CO2 measurements. To promote understanding of climate change effects in semi-arid regions, it is important to continue monitoring trends in CO2 uptake with GOSAT.", "labels": [ { "id": 10, "name": "Greenhouse Gases" } ] }, { "doi": "10.26848/RBGF.V13.07.P3498-3517", "year": 2020, "title": "Soils in tropical karst, pedogenetic development and hydrological behavior: A theoretical review", "abstract": "Este trabalho teve como objetivo reunir informacoes sobre comportamento pedogenetico e hidrologico em areas de rochas carbonaticas de clima tropical. A execucao desta pesquisa foi embasada em artigos cientificos indexados, nacionais e internacionais, como tambem em livros, teses e dissertacoes relevantes para o tema proposto. O solo e um sistema multifasico, e os seus aspectos morfologicos e constitucionais atuam facilitando ou dificultando a permeabilidade da agua, assim cada horizonte pedologico funciona como um mecanismo em um mesmo perfil de solo. Os fatores fisicos/quimicos da agua tambem atuarao contribuindo para a classificacao dos grupos hidrologicos de solo. No Brasil, a Embrapa realizou classificacoes dos horizontes diagnosticos, dos grupos hidrologicos e dos tipos de solos, baseada em autores internacionais, adaptadas as condicoes tropicais. Mas as areas carsticas, que representam um percentual de 20% da superficie terrestre, podem apresentar condicoes particulares para a formacao de solo e para o comportamento hidrologico, podendo incluir zonas locais de alta permeabilidade, fuga de agua subterranea e eliminacao de residuos insatisfatorios. Solos de ambientes carsticos sao mal desenvolvidos, apresentam argilas avermelhadas de baixa atividade normalmente. No Brasil os estudos deste tipo de ambiente sao escassos, mas alguns trabalhos desenvolvidos em areas carsticas trazem algumas informacoes basicas sobre os solos. As pesquisas encontradas que trouxeram informacoes dos solos em carstes, foram plotadas no mapa brasileiro. A pesquisa demonstrou que ha um gap de informacoes para o desenvolvimento pedologico em areas carsticas, mas e possivel fazer associacoes entre estas classes de solo a outros ambientes, incluindo o comportamento hidrologico.Soils In Tropical Karst, Pedogenetic Development And Hydrological Behavior: A Theoretical Review A B S T R A C TThis work aimed to gather information on pedogenetic and hydrological behavior in carbonate rock areas of tropical climate. The execution of this research was based on indexed scientific articles, national and international, as well as on books, theses and dissertations relevant to the proposed theme. The soil is a multiphase system, and its morphological and constitutional aspects act to facilitate or hinder water permeability, so each pedological horizon works as a mechanism in the same soil profile. The physical / chemical factors of the water will also act contributing to the classification of soil hydrological groups. In Brazil, Embrapa carried out classifications of diagnostic horizons, hydrological groups and soil types, based on international authors, adapted to tropical conditions. However, karst areas, which represent a percentage of 20% of the earth's surface, may present particular conditions for soil formation and hydrological behavior, and may include local areas of high permeability, groundwater leakage and unsatisfactory waste disposal. Soils in karst environments are poorly developed, with reddish clays of low activity normally. In Brazil, studies of this type of environment are scarce, but some studies carried out in karst areas bring some basic information about the soils. The researchers found that brought information on soils in carstes, were plotted on the Brazilian map. Research has shown that there is an information gap for pedological development in karst areas, but it is possible to make associations between these soil classes and other environments, including hydrological behavior.Keywords: Soil Hydrological Groups; Tropical Soil; Karst.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/ACP-21-7695-2021", "year": 2021, "title": "Stratospheric gravity waves over the mountainous island of South Georgia: testing a high-resolution dynamical model with 3-D satellite observations and \u2026", "abstract": "Abstract. Atmospheric gravity waves (GWs) play an important role in atmospheric dynamics but accurately representing them in general circulation models (GCMs) is challenging. This is especially true for orographic GWs generated by wind flow over small mountainous islands in the Southern Ocean. Currently, these islands lie in the grey zone of global model resolution, where they are neither fully resolved nor fully parameterised. It is expected that as GCMs approach the spatial resolution of current high-resolution local-area models, small-island GW sources may be resolved without the need for parameterisations. But how realistic are the resolved GWs in these high-resolution simulations compared to observations? Here, we test a high-resolution (1.5 km horizontal grid, 118 vertical levels) local-area configuration of the Met Office Unified Model over the mountainous island of South Georgia (54 S, 36 W), running without GW parameterisations. The island's orography is well resolved in the model, and real-time boundary conditions are used for two time periods during July 2013 and JuneJuly 2015. We compare simulated GWs in the model to coincident 3-D satellite observations from the Atmospheric Infrared Sounder (AIRS) on board Aqua. By carefully sampling the model using the AIRS resolution and measurement footprints (denoted as model sampled as AIRS hereafter), we present the first like-for-like comparison of simulated and observed 3-D GW amplitudes, wavelengths and directional GW momentum flux (GWMF) over the island using a 3-D S-transform method. We find that the timing, magnitude and direction of simulated GWMF over South Georgia are in good general agreement with observations, once the AIRS sampling and resolution are applied to the model. Area-averaged zonal GWMF during these 2 months is westward at around 5.3 and 5.6 mPa in AIRS and model sampled as AIRS datasets respectively, but values directly over the island can exceed 50 mPa. However, up to 35 % of the total GWMF in AIRS is actually found upwind of the island compared to only 17 % in the model sampled as AIRS, suggesting that non-orographic GWs observed by AIRS may be underestimated in our model configuration. Meridional GWMF results show a small northward bias (20 %) in the model sampled as AIRS that may correspond to a southward wind bias compared to coincident radiosonde measurements. Finally, we present one example of large-amplitude (T1520 K at 45 km altitude) GWs at short horizontal wavelengths (H3040 km) directly over the island in AIRS measurements that show excellent agreement with the model sampled as AIRS. This suggests that orographic GWs in the full-resolution model with T45 K and H3040 km can occur in reality. Our study demonstrates that not only can high-resolution local-area models simulate realistic stratospheric GWs over small mountainous islands but the application of satellite sampling and resolution to these models can also be a highly effective method for their validation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1080/01431161.2021.2009149", "year": 2022, "title": "Evaluation of ACOLITE atmospheric correction methods for Landsat-8 and Sentinel-2 in the R\u00edo de la Plata turbid coastal waters", "abstract": "Landsat-8 (L8) and Sentinel-2 (S2) terrestrial satellite missions have shown to contain useful information for aquatic applications. However, quantitative retrieval of water quality parameters, such as turbidity, strongly depend on the performance of atmospheric correction algorithms. Among available processors, ACOLITE (https://odnature.naturalsciences.be/remsem/software-and-data/acolite) is simple to incorporate in imagery processing routines and has shown to have better performance than other processors for sediment-rich waters. Recently (in 2018), it incorporated a new default atmospheric correction approach, the dark spectrum fit (DSF), which remains to be tested in most of the Southern hemisphere coastal areas. In this work, we present new in-situ radiometric measurements collected in the northern coast of the Rio de la Plata estuary, South America, during field campaigns along a 2-year period. The data set was used to evaluate the performance of ACOLITEs DSF and exponential extrapolation (EXP) methods with L8 and S2 imagery, and to recalibrate a turbidity algorithm. The DSF did not perform very well, giving particularly poor results in the near infrared (NIR) bands. However, its performance was greatly improved with an optional sun glint correction (DSF+GC), although some positive bias was still present in the NIR bands. A GC seemed to be most important in dates with higher sun elevation (austral spring and summer), and should be strongly considered for other water bodies in the region and in similar or lower latitudes (35S). Additionally, the EXP method gave good results in the green-NIR spectral region when a low (5th) percentile aerosol type was selected. Finally, the effect of the atmospheric correction on turbidity retrieval from satellite imagery was assessed: if the red and a NIR band were combined, the effect of the bias in the NIR region was negligible for the DSF+GC method; however, some impact was noticed for the lowest turbidity levels if a single NIR band was used.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/2017JG003794", "year": 2017, "title": "Large Uncertainty in Estimating pCO2 From Carbonate Equilibria in Lakes", "abstract": "Most estimates of carbon dioxide (CO2) evasion from freshwaters rely on calculating partial pressure of aquatic CO2 (pCO2) from two out of three CO2-related parameters using carbonate equilibria. However, the pCO2 uncertainty has not been systematically evaluated across multiple lake types and equilibria. We quantified random errors in pH, dissolved inorganic carbon, alkalinity, and temperature from the North Temperate Lakes Long-Term Ecological Research site in four lake groups across a broad gradient of chemical composition. These errors were propagated onto pCO2 calculated from three carbonate equilibria, and for overlapping observations, compared against uncertainties in directly measured pCO2. The empirical random errors in CO2-related parameters were mostly below 2% of their median values. Resulting random pCO2 errors ranged from \u00b13.7% to \u00b131.5% of the median depending on alkalinity group and choice of input parameter pairs. Temperature uncertainty had a negligible effect on pCO2. When compared with direct pCO2 measurements, all parameter combinations produced biased pCO2 estimates with less than one third of total uncertainty explained by random pCO2 errors, indicating that systematic uncertainty dominates over random error. Multidecadal trend of pCO2 was difficult to reconstruct from uncertain historical observations of CO2-related parameters. Given poor precision and accuracy of pCO2 estimates derived from virtually any combination of two CO2-related parameters, we recommend direct pCO2 measurements where possible. To achieve consistently robust estimates of CO2 emissions from freshwater components of terrestrial carbon balances, future efforts should focus on improving accuracy and precision of CO2-related parameters (including direct pCO2) measurements and associated pCO2 calculations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS13101992", "year": 2021, "title": "Assessment of the EUMETSAT Multi Decadal Land Surface Albedo Data Record", "abstract": "Surface albedo, defined as the ratio of the surface-reflected irradiance to the incident irradiance, is one of the parameters driving the Earth energy budget and it is for this reason an essential variable in climate studies. Instruments on geostationary satellites provide suitable observations allowing long-term monitoring of surface albedo from space. In 2012, EUMETSAT published Release 1 of the Meteosat Surface Albedo (MSA) data record. The main limitation effecting the quality of this release was non-removed clouds by the incorporated cloud screening procedure that caused too high albedo values, in particular for regions with permanent cloud coverage. For the generation of Release 2, the MSA algorithm has been replaced with the Geostationary Surface Albedo (GSA) one, able to process imagery from any geostationary imager. The GSA algorithm exploits a new, improved, cloud mask allowing better cloud screening, and thus fixing the major limitation of Release 1. Furthermore, the data record has an extended temporal and spatial coverage compared to the previous release. Both Black-Sky Albedo (BSA) and White-Sky Albedo (WSA) are estimated, together with their associated uncertainties. A direct comparison between Release 1 and Release 2 clearly shows that the quality of the retrieval improved significantly with the new cloud mask. For Release 2 the decadal trend is less than 1% over stable desert sites. The validation against Moderate Resolution Imaging Spectroradiometer (MODIS) and the Southern African Regional Science Initiative (SAFARI) surface albedo shows a good agreement for bright desert sites and a slightly worse agreement for urban and rain forest locations. In conclusion, compared with MSA Release 1, GSA Release 2 provides the users with a significantly more longer time range, reliable and robust surface albedo data record.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S00190-022-01651-8", "year": 2022, "title": "Feasibility of a global inversion for spatially resolved glacial isostatic adjustment and ice sheet mass changes proven in simulation experiments", "abstract": "Estimating mass changes of ice sheets or of the global ocean from satellite gravimetry strongly depends on the correction for the glacial isostatic adjustment (GIA) signal. However, geophysical GIA models are different and incompatible with observations, particularly in Antarctica. Regional inversions have resolved GIA over Antarctica without ensuring global consistency, while global inversions have been mostly constrained by a priori GIA patterns. For the first time, we set up a global inversion to simultaneously estimate ice sheet mass changes and GIA, where Antarctic GIA is spatially resolved using a set of global GIA patterns. The patterns are related to deglaciation impulses localized along a grid over Antarctica. GIA associated with four regions outside Antarctica is parametrized by global GIA patterns induced by deglaciation histories. The observations we consider here are satellite gravimetry, satellite altimetry over Antarctica and Greenland, as well as modelled firn thickness changes. Firn thickness changes are also parametrized to account for systematic errors in their modelling. Results from simulation experiments using realistic signals and error covariances support the feasibility of the approach. For example, the spatial RMS error of the estimated Antarctic GIA effect, assuming a 10-year observation period, is 31% and 51%, of the RMS of two alternative global GIA models. The integrated Antarctic GIA error is 8% and 5%, respectively, of the integrated GIA signal of the two models. For these results realistic error covariances incorporated in the parameter estimation process are essential. If error correlations are neglected, the Antarctic GIA RMS error is more than twice as large.Highlights$$\\bullet $$We present a globally consistent inversion approach to co-estimate glacial isostatic adjustment effects together with changes of the ice mass and firn air content in Greenland and Antarctica. $$\\bullet $$The inversion method utilizes data sets from satellite gravimetry, satellite altimetry, regional climate modelling, and firn modelling together with the full error-covariance information of all input data. $$\\bullet $$The simulation experiments show that the proposed GIA parametrization in Antarctica can resolve GIA effects unpredicted by geophysical modelling, despite realistic input-data limitations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/RS13122357", "year": 2021, "title": "Evaluation of the MODIS (C6) Daily Albedo Products for Livingston Island, Antarctic", "abstract": "Although extensive research of Moderate Resolution Imaging Spectroradiometer (MODIS) albedo data is available on the Greenland Ice Sheet, there is a lack of studies evaluating MODIS albedo products over Antarctica. In this paper, MOD10A1, MYD10A1, and MCD43 (C6) daily albedo products were compared with the in situ albedo data on Livingston Island, South Shetland Islands (SSI), Antarctica, from 2006 to 2015, for both all-sky and clear-sky conditions, and for the entire study period and only the southern summer months. This is the first evaluation in which MYD10A1 and MCD43 are also included, which can be used to improve the accuracy of the snow BRDF/albedo modeling. The best correlation was obtained with MOD10A1 in clear-sky conditions (r = 0.7 and RMSE = 0.042). With MCD43, only data from the backup algorithm could be used, so the correlations obtained were lower (r = 0.6). However, it was found that there was no significant difference between the values obtained for all-sky and for clear-sky data. In addition, the MODIS products were found to describe the in situ data trend, with increasing albedo values in the range between 0.04 decade1 and 0.16 decade1. We conclude that MODIS daily albedo products can be applied to study the albedo in the study area.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.2151/JMSJ.2021-048", "year": 2021, "title": "Validation of GSMaP Products for a Heavy Rainfall Event over Complex Terrain in Mongolia Captured by the GPM Core Observatory", "abstract": "This paper focuses on the uncertainty of summer precipitation estimations produced by Global Satellite Mapping of Precipitation (GSMaP) over Mongolia, a region that has complex terrain and sparse weather observation networks. We first compared average summer precipitation over Mongolian territory as reported by several precipitation products. Although the interannual variability of the product was comparable, the amount of recorded precipitation differed among the various products. The rain-gauge-based analysis reported the lowest amount of precipitation, while the satellite-based GSMaP_MVK reported the highest amount. Our results represent a first estimate of the characteristic differences among the various precipitation-monitoring products, including GPM-based products, as they relate to climatic and hydro-meteorological assessments in Mongolia. We then made a detailed comparison using a case study in which a heavy rainfall event was captured by the Global Precipitation Measurement (GPM) mission's core observatory near Ulaanbaatar in July 2016. In this case, gauged and ungauged GSMaP estimates of the precipitation over the mountain area differed substantially between algorithm versions 6 and 7. An intercomparison of atmospheric numerical modeling, the GPM core observatory, and rain gauge observation showed that the rain gauge calibration of GSMaP effectively moderates the large error of the ungauged GSMaP data. The source of the significant ungauged GSMaP error is likely to be the rain rate estimates in version 7 of the algorithm. However, GSMaP gauge-calibrated estimates of the precipitation over mountainous areas may be affected by a potential underestimation of gauge analysis due to the missing localized precipitation occurring in the large gaps of the routine observation network. We expect that these findings will be helpful for developers seeking to further improve the GSMaP algorithm.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.2166/NH.2018.110", "year": 2019, "title": "Multi-objective calibration of MIKE SHE with SMAP soil moisture datasets", "abstract": "Root zone soil moisture plays an important role in water storage in hydrological processes. The recently launched Soil Moisture Active Passive (SMAP) mission has produced a high-resolution assimilation product of global root zone soil moisture that can be applied to improve the performance of hydrological models. In this study, we compare three calibration approaches in the Beimiaoji watershed. The first approach is single-objective calibration, in which only observed streamflow is used as a benchmark for comparison with the other approaches. The second and third approaches use multi-objective calibration based on SMAP root zone soil moisture and observed streamflow. The difference between the second and third approaches is the metric used to characterize the root zone soil moisture. The second approach applies the mean, which was commonly used in previous studies, whereas the third approach applies the hydrologic complexity , a dimensionless metric based on information entropy theory. These approaches are implemented to calibrate the distributed hydrological model MIKE SHE. Results show that the root zone soil moisture simulation is clearly improved, whereas streamflow simulation suffers from a slightly negative impact with multi-objective calibration. The hydrologic complexity performs better than the mean in capturing the features of root zone soil moisture.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1364/AO.469584", "year": 2022, "title": "ICESat-2 laser data denoising algorithm based on a back propagation neural network", "abstract": "The Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) photon data is the emerging satellite-based LiDAR data, widely used in surveying and mapping due to its small photometric spot and high density. Since ICESat-2 data collect weak signals, it is difficult to denoise in shallow sea island areas, and the quality of the denoising method will directly affect the precision of bathymetry. This paper proposes a back propagation (BP) neural network-based denoising algorithm for the data characteristics of shallow island reef areas. First, a horizontal elliptical search area is constructed for the photons in the dataset. Suitable feature values are selected in the search area to train the BP neural network. Finally, data with a geographic location far apart, including daily and nightly data, are selected respectively for experiments to test the generality of the network. By comparing the results with the confidence labels provided in the official documents of the ATL03 dataset, the DBSCAN algorithm, and the manual visual interpretation, it is proved that the denoising algorithm proposed in this paper has a better processing effect in shallow island areas.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/OS-18-109-2022", "year": 2022, "title": "Components of 21 years (1995\u20132015) of absolute sea level trends in the Arctic", "abstract": "Abstract. The Arctic Ocean is at the frontier of the fast-changing climate in the northern latitudes, and sea level trends are a bulk measure of ongoing processes related to climate change. Observations of sea level in the Arctic Ocean are nonetheless difficult to validate with independent measurements, and this is globally the region where the sea level trend (SLT) is most uncertain. The aim of this study is to create a satellite-independent reconstruction of Arctic SLT, as it is observed by altimetry and tide gauges (TGs). Previous studies use Gravity Recovery and Climate Experiment (GRACE) observations to estimate the manometric (mass component of) SLT. GRACE estimates, however, are challenged by large mass changes on land, which are difficult to separate from much smaller ocean mass changes. Furthermore, GRACE is not available before 2003, which significantly limits the period and makes the trend more vulnerable to short-term changes. As an alternative approach, this study estimates the climate-change-driven Arctic manometric SLT from the Arctic sea level fingerprints of glaciers, Greenland, Antarctica and glacial isostatic adjustment (GIA) with the addition of the long-term inverse barometer (IB) effect. The halosteric and thermosteric components complete the reconstructed Arctic SLT and are estimated by interpolating 300 000 temperature (T) and salinity (S) in situ observations. The SLT from 19952015 is compared to the observed SLT from altimetry and 12 selected tide gauges (TGs) corrected for vertical land movement (VLM). The reconstructed estimate manifests the salinity-driven halosteric component as dominating the spatial SLT pattern with variations between 7 and 10 mm yr1. The manometric SLT in comparison is estimated to be 12 mm yr1 for most of the Arctic Ocean. The reconstructed SLT shows a larger sea level rise in the Beaufort Sea compared to altimetry, an issue that is also identified by previous studies. There is a TG-observed sea level rise in the Siberian Arctic in contrast to the sea level fall from the reconstructed and altimetric estimate. From 19952015 the reconstructed SLT agrees within the 68 % confidence interval with the SLT from observed altimetry in 87 % of the Arctic between 65 N and 82 N (R=0.50) and with 5 of 12 TG-derived (VLM-corrected) SLT estimates. The residuals are seemingly smaller than results from previous studies using GRACE estimates and modeled TS data. The spatial correlation of the reconstructed SLT to altimetric SLT during the GRACE period (20032015) is R=0.38 and R=0.34/R=0.37 if GRACE estimates are used instead of the constructed manometric component. Thus, the reconstructed manometric component is suggested as a legitimate alternative to GRACE that can be projected into the past and future.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 2, "name": "Atmospheric/Ocean Indicators" } ] }, { "doi": "10.3390/ATMOS8030052", "year": 2017, "title": "Evaluating the hydrological cycle over land using the newly-corrected precipitation climatology from the Global Precipitation Climatology Centre (GPCC)", "abstract": "The 2015 release of the precipitation climatology from the Global Precipitation Climatology Centre (GPCC) for 19512000, based on climatological normals of about 75,100 rain gauges, allows for quantification of mean land surface precipitation as part of the global water cycle. In GPCCs 2011-release, a bulk climatological correction was applied to compensate for gauge undercatch. In this paper we derive an improved correction approach based on the synoptic weather reports for the period 19822015. The compared results show that the climatological approach tends to overestimate the correction for Central and Eastern Europe, especially in the northern winter, and in other regions throughout the year. Applying the mean weather-dependent correction to the GPCCs uncorrected precipitation climatology for 19512000 gives a value of 854.7 mm of precipitation per year (excluding Antarctica) or 790 mm for the global land surface. The warming of nearly 1 K relative to pre-industrial temperatures is expected to be accompanied by a 2%3% increase in global (land and ocean) precipitation. However, a comparison of climatology for 30-year reference periods from 19311960 up to 19812010 reveals no significant trend for land surface precipitation. This may be caused by the large variability of precipitation, the varying data coverage over time and other issues related to the sampling of rain-gauge networks. The GPCC continues to enlarge and further improve the quality of its database, and will generate precipitation analyses with homogeneous data coverage over time. Another way to reduce the sampling issues is the combination of rain gauge-based analyses with remote sensing (i.e., satellite or radar) datasets.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2017WR022437", "year": 2018, "title": "Satellite Remote Sensing for Water Resources Management: Potential for", "abstract": "Water resources management (WRM) for sustainable development presents many challenges in areas with sparse in situ monitoring networks. The exponential growth of satellite based information over the past decade provides unprecedented opportunities to support and improve WRM. Furthermore, traditional barriers to the access and usage of satellite data are lowering as technological innovations provide opportunities to manage and deliver this wealth of information to a wider audience. We review data needs for WRM and the role that satellite remote sensing can play to fill gaps and enhance WRM, focusing on the Latin American and Caribbean as an example of a region with potential to further develop its resources and mitigate the impacts of hydrological hazards. We review the state-of-the-art for relevant variables, current satellite missions, and products, how they are being used currently by national agencies across the Latin American and Caribbean region, and the challenges to improving their utility. We discuss the potential of recently launched, upcoming, and proposed missions that are likely to further enhance and transform assessment and monitoring of water resources. Ongoing challenges of accuracy, sampling, and continuity still need to be addressed, and further challenges related to the massive amounts of new data need to be overcome to best leverage the utility of satellite based information for improving WRM.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3847/1538-3881/ABD54A", "year": 2021, "title": "Earth as a Proxy Exoplanet: Deconstructing and Reconstructing", "abstract": "Abstract\r\n Point-source spectrophotometric (single-point) light curves of Earth-like planets contain a surprising amount of information about the spatial features of those worlds. Spatially resolving these light curves is important for assessing time-varying surface features and the existence of an atmosphere, which in turn is critical to life on Earth and significant for determining habitability on exoplanets. Given that Earth is the only celestial body confirmed to harbor life, treating it as a proxy exoplanet by analyzing time-resolved spectral images provides a benchmark in the search for habitable exoplanets. The Earth Polychromatic Imaging Camera (EPIC) on the Deep Space Climate Observatory (DSCOVR) provides such an opportunity, with observations of 5000 full-disk sunlit Earth images each year at 10 wavelengths with high temporal frequency. We disk-integrate these spectral images to create single-point light curves and decompose them into principal components (PCs). Using machine-learning techniques to relate the PCs to six preselected spatial features, we find that the first and fourth PCs of the single-point light curves, contributing 83.23% of the light-curve variability, contain information about low and high clouds, respectively. Surface information relevant to the contrast between land and ocean reflectance is contained in the second PC, while individual land subtypes are not easily distinguishable (<0.1% total light-curve variation). We build an Earth model by systematically altering the spatial features to derive causal relationships to the PCs. This model can serve as a baseline for analyzing Earth-like exoplanets and guide wavelength selection and sampling strategies for future observations.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1109/TGRS.2022.3177600", "year": 2022, "title": "A data-driven deep learning model for weekly sea ice concentration prediction of the Pan-Arctic during the melting season", "abstract": "This study proposes a purely data-driven model for the weekly prediction of daily sea ice concentration (SIC) of the pan-Arctic (90 N, 45 N, 180 E, 180 W) during the melting season. The model, SICNet, adopts an encoderdecoder framework with fully convolutional networks (FCNs) and can predict the SIC (covering 2$ in the SIE error.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 3, "name": "Cryospheric Indicators" } ] }, { "doi": "10.1109/IDAACS.2017.8095248", "year": 2017, "title": "Array DBMS in environmental science: Satellite sea surface height data in the Cloud", "abstract": "Nowadays environmental science experiences tremendous growth of raster data: N-dimensional (N-d) arrays coming mainly from numeric simulation and Earth remote sensing. An array DBMS is a tool to streamline raster data processing. However, raster data are usually stored in files, not in databases. Moreover, numerous command line tools exist for processing raster files. This paper describes a distributed array DBMS under development that partially delegates raster data processing to such tools. Our DBMS offers a new N-d array data model to abstract from the files and the tools and processes data in a distributed fashion directly in their native file formats. As a case study, popular satellite altimetry data were used for the experiments carried out on 8- and 16-nodes clusters in Microsoft Azure Cloud. New array DBMS is up to 70 faster than SciDB which is the only freely available distributed array DBMS to date.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1007/S41324-019-00310-Z", "year": 2020, "title": "Development of mapping techniques for off road trafficability to support military operation", "abstract": "Terrain plays a vital role in any military operation, however terrain trafficability assessment is the key requirement for planning any military operation in advance. In this study, terrain conditions for off-road trafficability assessment, an integrated approach used because it is affected by large number of factors. While evaluating terrain mobility, its topography along with land use/land cover are important factors. Maps have been the basic ingredient of topographic information throughout history of planning. In the current context of work, to generate mobility maps, an out-of-box methodology was experimented. This was performed by evaluating the relative direct and in-direct parameters from satellite data and terrain ancillary information. Hence the main objective of this study was to assess the potential of all the factors in providing relevant assisting information for vehicle mobility. To assess the relative importance of factors and its contribution in estimating off road trafficability requires the domain expertise and field experience. Based on qualitative assessment along with field studies, the overall impact can be converted into quantitative terms and ultimately it will pave the way for automation of trafficability, which will be useful in planning of corridors during military operations.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2019GL086426", "year": 2020, "title": "Constraining Reanalysis Snowfall Over the Arctic Ocean Using CloudSat Observations", "abstract": "In the absence of widespread snowfall observations over the Arctic Ocean, reanalysis products provide a wide range of estimates of time-evolving snowfall rates over Arctic sea ice, and it can be difficult to determine which product is most representative. In this work, Arctic snowfall rates retrieved from 2006 to 2016 CloudSat observations and snowfall products from three reanalyses are assessed. The products can be brought into encouraging agreement over the region on interannual time scales once differences in spatial representativeness and temporal sampling are accounted for. This motivates the use of CloudSat's snowfall product to calibrate reanalysis snowfall. The calibration is carried out for four Arctic quadrants and combined to produce regionally resolved and consistent estimates of interannually varying snowfall. Calibrated reanalysis snowfall inputs are then used to drive the NASA Eulerian Snow On Sea Ice Model, reducing the interproduct spread in the resulting simulated snow depths across the Arctic.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2018EA000508", "year": 2019, "title": "The Atmospheric Infrared Sounder Obs4MIPs Version 2 Data Set", "abstract": "The Atmospheric Infrared Sounder (AIRS) Obs4MIPs (Observations for Model Intercomparison Projects) Version 2 data set includes monthly mean tropospheric air temperature, specific humidity, and relative humidity for each calendar month from September 2002 to September 2016, on a global 1\u00b0 \u00d7 1\u00b0 latitude-longitude spatial grid and on the Coupled Model Intercomparison Project eight mandatory vertical pressure levels from 1,000 to 300 hPa. It also includes standard error and number of observations, for an estimate of AIRS data retrieval error and sampling uncertainty. Three new technical notes describe the data set. This data set is designed for Coupled Model Intercomparison Project climate model evaluation and has been published at Earth System Grid Federation data centers since April 2018. It adds new monthly mean tropospheric relative humidity data to Obs4MIPs and updates and extends the monthly mean tropospheric air temperature and specific humidity data in AIRS Obs4MIPs Version 1 data set. The data source for this data set is the AIRS Version 6 Level 3 standard monthly mean air temperature, specific humidity, and relative humidity data products in the \"TqJoint\" grids from the AIRS and Advanced Microwave Sounding Unit A combined physical retrievals. This paper documents this data set in terms of motivation for this data set, data description, data origin and processing procedures, major improvements from the previous version, and caveats for its use in climate model evaluation.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-15-6329-2022", "year": 2022, "title": "Intercomparison of airborne and surface-based measurements during the CLARIFY, ORACLES and LASIC field experiments", "abstract": "Abstract. Data are presented from intercomparisons between two\nresearch aircraft, the FAAM BAe-146 and the NASA Lockheed P3, and between\nthe BAe-146 and the surface-based DOE (Department of Energy) ARM\n(Atmospheric Radiation Measurement) Mobile Facility at Ascension Island\n(8 S, 14.5 W; a remote island in the mid-Atlantic).\nThese took place from 17 August to 5 September 2017, during the African\nbiomass burning (BB) season. The primary motivation was to give confidence in the\nuse of data from multiple platforms with which to evaluate numerical climate\nmodels. The three platforms were involved in the CLoudsAerosolRadiation\nInteraction and Forcing for Year 2017 (CLARIFY-2017), ObseRvations of\nAerosols above CLouds and their intEractionS (ORACLES), and Layered Atlantic\nSmoke and Interactions with Clouds (LASIC) field experiments. Comparisons\nfrom flight segments on 6 d where the BAe-146 flew alongside the ARM\nfacility on Ascension Island are presented, along with comparisons from the\nwing-tip-to-wing-tip flight of the P3 and BAe-146 on 18 August 2017.\nThe intercomparison flight sampled a relatively clean atmosphere overlying a\nmoderately polluted boundary layer, while the six fly-bys of the ARM site\nsampled both clean and polluted conditions 24 km upwind. We compare and\nvalidate characterisations of aerosol physical, chemical and optical\nproperties as well as atmospheric radiation and cloud microphysics between platforms.\nWe assess the performance of measurement instrumentation in the field, under\nconditions where sampling conditions are not as tightly controlled as in\nlaboratory measurements where calibrations are performed. Solar radiation\nmeasurements compared well enough to permit radiative closure studies.\nOptical absorption coefficient measurements from all three platforms were\nwithin uncertainty limits, although absolute magnitudes were too low\n(<10 Mm1) to fully support a comparison of the absorption\nAngstrom exponents. Aerosol optical absorption measurements from\nairborne platforms were more comparable than aircraft-to-ground\nobservations. Scattering coefficient observations compared adequately\nbetween airborne platforms, but agreement with ground-based measurements was\nworse, potentially caused by small differences in sampling conditions or\nactual aerosol population differences over land. Chemical composition\nmeasurements followed a similar pattern, with better comparisons between the\nairborne platforms. Thermodynamics, aerosol and cloud microphysical\nproperties generally agreed given uncertainties.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.3390/SU13010108", "year": 2021, "title": "Localizing the Water-Energy Nexus: The Relationship between Solar", "abstract": "Water availability plays an important role in the expansion planning of utility-scale solar power plants, especially in the arid regions of the Middle East and North Africa. Although these power plants usually account for only a small fraction of local water demand, competition for water resources between communities, farmers, companies, and power suppliers is already emerging and is likely to intensify in future. Despite this, to date there has been a lack of comprehensive studies analyzing interdependencies and potential conflicts between energy and water at local level. This study addresses this research gap and examines the linkages between water resources and energy technologies at local level based on a case study conducted in Ouarzazate, Morocco, where one of the largest solar power complexes in the world was recently completed. To better understand the challenges faced by the region in light of increased water demand and diminishing water supply, a mixed-method research design was applied to integrate the knowledge of local stakeholders through a series of workshops. In a first step, regional socio-economic water demand scenarios were developed and, in a second step, water saving measures to avoid critical development pathways were systematically evaluated using a participatory multi-criteria evaluation approach. The results are a set of water demand scenarios for the region and a preferential ranking of water saving measures that could be drawn upon to support decision-making relating to energy and water development in the region.", "labels": [ { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.5194/ACP-18-13881-2018", "year": 2018, "title": "Atmospheric CO and CH4 time series and seasonal variations on Reunion Island from ground-based in situ and FTIR (NDACC and TCCON) measurements", "abstract": "Abstract. Atmospheric carbon monoxide (CO) and methane (CH4) mole fractions are measured by ground-based in situ cavity ring-down spectroscopy (CRDS) analyzers and Fourier transform infrared (FTIR) spectrometers at two sites (St Denis and Maido) on Reunion Island (21 S, 55 E) in the Indian Ocean. Currently, the FTIR Bruker IFS 125HR at St Denis records the direct solar spectra in the near-infrared range, contributing to the Total Carbon Column Observing Network (TCCON). The FTIR Bruker IFS 125HR at Maido records the direct solar spectra in the mid-infrared (MIR) range, contributing to the Network for the Detection of Atmospheric Composition Change (NDACC). In order to understand the atmospheric CO and CH4 variability on Reunion Island, the time series and seasonal cycles of CO and CH4 from in situ and FTIR (NDACC and TCCON) measurements are analyzed. Meanwhile, the difference between the in situ and FTIR measurements are discussed. The CO seasonal cycles observed from the in situ measurements at Maido and FTIR retrievals at both St Denis and Maido are in good agreement with a peak in SeptemberNovember, primarily driven by the emissions from biomass burning in Africa and South America. The dry-air column averaged mole fraction of CO (XCO) derived from the FTIR MIR spectra (NDACC) is about 15.7 ppb larger than the CO mole fraction near the surface at Maido, because the air in the lower troposphere mainly comes from the Indian Ocean while the air in the middle and upper troposphere mainly comes from Africa and South America. The trend for CO on Reunion Island is unclear during the 20112017 period, and more data need to be collected to get a robust result. A very good agreement is observed in the tropospheric and stratospheric CH4 seasonal cycles between FTIR (NDACC and TCCON) measurements, and in situ and the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) satellite measurements, respectively. In the troposphere, the CH4 mole fraction is high in AugustSeptember and low in DecemberJanuary, which is due to the OH seasonal variation. In the stratosphere, the CH4 mole fraction has its maximum in MarchApril and its minimum in AugustOctober, which is dominated by vertical transport. In addition, the different CH4 mole fractions between the in situ, NDACC and TCCON CH4 measurements in the troposphere are discussed, and all measurements are in good agreement with the GEOS-Chem model simulation. The trend of XCH4 is 7.60.4 ppb yr1 from the TCCON measurements over the 2011 to 2017 time period, which is consistent with the CH4 trend of 7.40.5 ppb yr1 from the in situ measurements for the same time period at St Denis.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1038/S41597-019-0122-6", "year": 2019, "title": "A high-resolution gridded dataset to assess electrification in sub-Saharan Africa", "abstract": "Spatially explicit data on electricity access and use are essential for effective policy-making and infrastructure planning in low-income, data-scarce regions. We present and validate a 1-km resolution electricity access dataset covering sub-Saharan Africa built on gridded nighttime light, population, and land cover data. Using light radiance probability distributions, we define electricity consumption tiers for urban and rural areas and estimate the by-tier split of consumers living in electrified areas. The approach provides new insight into the spatial distribution and temporal evolution of electricity access, and a measure of its quality beyond binary access. We find our estimates to be broadly consistent with recently published province- and national-level statistics. Moreover, we demonstrate consistency between the estimated electricity access quality indicators and survey-based consumption levels defined in accordance with the World Bank Multi-Tier Framework. The dataset is readily reproduced and updated using an open-access scientific computing framework. The data and approach can be applied for improving the assessment of least-cost electrification options, and examining links between electricity access and other sustainable development objectives.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1002/JOC.6609", "year": 2021, "title": "Trends in sunshine duration in Poland (1971\u20132018)", "abstract": "AbstractThis study aims to characterize temporal and spatial trends of sunshine duration in Poland based on data from the years 19712018 and to make an attempt to explain their causes. Daily sunshine duration came from 31 Polish meteorological stations. Data from 10 stations came only from a traditional CampbellStokes heliograph, while in the other 21 synoptic stations CampbellStokes heliograph was replaced with an automatic sensor in 2014 and since then only such data are available. The smallest sunshine duration occurs in December (average areal total39.7 hr), and the highest in July (average areal total230.1 hr). The spatial distribution of sunshine duration in Poland shows great diversity associated with different day lengths depending on latitude. In the cool part of the year (November, December, January, and February) the isolines of totals of sunshine duration run from the highest values in the south to the lowest in the north of the country, while in the months of the warm part of the year (March to September) the system is reversed. The multiannual trends in sunshine duration in Poland are similar to the changes taking place in other parts of the world. The years 19711980 mark the end of global dimming, which was manifested in very low values of actual and relative sunshine duration. Global brightening confirms a statistically significant growing trend in sunshine duration at all the analysed meteorological stations in Poland from April to September. There is a strong statistically significant relationship between the areal totals of sunshine duration and the type of pressure system, average monthly cloud cover, and atmospheric optical depth.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1088/1755-1315/645/1/012017", "year": 2021, "title": "Comprehensive evaluation method of micro-energy harvesters for power supply of outdoor wireless sensors", "abstract": "Abstract\r\n There have been many solar or wind micro-energy collection technologies for outdoor wireless sensors, but it is difficult to compare them horizontally and choose the appropriate scheme. To overcome this problem, this paper proposes a comprehensive evaluation method of micro-energy harvesters which includes an evaluation matrix composed of three types of indexes and the corresponding test method. After the evaluation matrix is obtained by testing, a CRITIC-based weight calculation method is used to get a comprehensive score. Finally, ten commonly used solar or wind micro-energy harvesters in five typical regions are compared horizontally by the proposed method. The results show that the evaluation method can comprehensively consider various factors, and harvesters with higher comprehensive scores tend to have more balanced performance in all aspects. Furthermore, in regions with rich wind resources, the wind and solar harvesters have complementary time-domain characteristics.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1007/978-981-15-6198-6_22", "year": 2021, "title": "An Improved ANN Model for Prediction of Solar Radiation Using Machine Learning Approach", "abstract": "An accurate forecast of weather is essential for obtaining energy from Renewable sources. The objective of this paper is to present an analysis of weather parameters and comparison among different models of the weather prediction from accessible parameters and finally deriving a new technique for solar prediction in support of photovoltaic output power. Artificial Neural Network model with 5 weather parameters from NASA POWER dataset have been utilized to predict the day-ahead solar radiation and evaluated against real data measured for 4 years at Agartala, India (Latitude 23.83 N and Longitude 91.282 E). Results detailed in this work confirm the best predicting potential of the proposed method. The proposed model has been shown to predict solar radiation with accuracy of 83% shows the robustness of the system.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1038/S41598-021-98622-4", "year": 2021, "title": "Evaluation of MODIS-derived estimates of the albedo over the Atacama Desert using ground-based spectral measurements", "abstract": "Surface albedo is an important forcing parameter that drives the radiative energy budget as it determines the fraction of the downwelling solar irradiance that the surface reflects. Here we report on ground-based measurements of the spectral albedo (3502200 nm) carried out at 20 sites across a NorthSouth transect of approximately 1300 km in the Atacama Desert, from latitude 18 S to latitude 30 S. These spectral measurements were used to evaluate remote sensing estimates of the albedo derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). We found that the relative mean bias error (RMBE) of MODIS-derived estimates was within 5% of ground-based measurements in most of the Atacama Desert (1827 S). Although the correlation between MODIS-derived estimates and ground-based measurements remained relatively high (R= 0.94), RMBE values were slightly larger in the southernmost part of the desert (2730 S). Both MODIS-derived data and ground-based measurements show that the albedo at some bright spots in the Atacama Desert may be high enough (up to 0.25 in visible range) for considerably boosting the performance of bifacial photovoltaic technologies (612%).", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1175/JAMC-D-16-0085.1", "year": 2017, "title": "A simple new model for incoming solar radiation dependent only on screen-level relative humidity", "abstract": "Abstract Global incoming shortwave radiation (Rg) is the energy source for the majority of biogeochemical processes on Earth as well as for photovoltaic power production. Existing simple site-specific models to estimate Rg commonly use the daily range of air temperature as input variables. Here, the authors present a simple model for incoming shortwave radiation, requiring only screen-level relative humidity data (and site-specific astronomical information). The model was developed and parameterized using high-quality global radiation data covering a broad range of climate conditions. It was evaluated at independent sites, which were not involved in the process of model development and parameterization. The mean 1:1 slope was 1.02 with an average r2 of 0.98. Normalized root-mean-square error (NRMSE) averaged at 43%. Despite its simplicity, the new model clearly outperforms conventional approaches, and it comes close to more labor- and data-intensive alternative models.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1029/2021EA002122", "year": 2022, "title": "SORCE and TSIS\u20101 SIM Comparison: Absolute Irradiance Scale Reconciliation", "abstract": "The Solar Radiation and Climate Experiment (SORCE) and Total and Spectral Irradiance Sensor (TSIS-1) conducted an intercomparison for the two Spectral Irradiance Monitors (SIM) spanning 704 days from 23 March 2018 to 25 February 2020 and permitted 554 time-matched pairs of observations. This comparison was conducted during the extremely quiescent Solar Cycle 24 minimum, so all observed differences and drifts between the two sensors are instrumental in nature. The TSIS-1 SIM benefitted from advanced calibration capabilities based on SI standards that were not available during the preflight calibration time period of SORCE. For this reason, a revision of the SORCE SIM absolute scale is appropriate. As expected, wavelength dependent differences in absolute agreement are a function of detector sensitivity and local changes in spectral slope. At the time of the comparison SORCE SIM has been on-orbit for 17 years while TSIS-1 observations commenced immediately after a 100-day outgassing and commissioning period. Peak-to-peak absolute scale differences are about 12% with a mean fractional difference of 0.7% \u00b1 2.9%. The greatest scale differences occur at the change-over between the UV and visible photodiodes in the 310 nm region, and a systematic disagreement is present in the 850-1,600 nm range. A multiplicative scale correction factor has been developed to reconcile the TSIS-1 and SORCE difference with a wavelength dependent error on the mean typically less than 0.01% derived from every matched pair of observations.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 17, "name": "Validation" } ] }, { "doi": "10.1088/1748-9326/AAF935", "year": 2019, "title": "Inter-annual variability of wind and solar electricity generation and capacity values in Texas", "abstract": "As power systems shift towards increasing wind and solar electricity generation, inter-annual variability (IAV) of wind and solar resource and generation will pose increasing challenges to power system planning and operations. To help gauge these challenges to the power system, we quantify IAV of wind and solar resource and electricity generation across the Electric Reliability Council of Texas (ERCOT) power system, then assess the IAV of wind and solar electricity generation during peak-load hours (i.e. IAV of wind and solar capacity values) for the current ERCOT wind and solar generator fleet. To do so, we leverage the long timespan of four reanalysis datasets with the high resolution of grid integration datasets. We find the IAV (quantified as the coefficient of variation) of wind generation ranges from 2.3%-11% across ERCOT, while the IAV of solar generation ranges from 1.7%-5% across ERCOT. We also find significant seasonal and regional variability in the IAV of wind and solar generation, highlighting the importance of considering multiple temporal and spatial scales when planning and operating the power system. In addition, the IAV of the current wind and solar fleets' capacity values (defined as generation during peak-load hours) are larger than the IAV of the same fleets' capacity factors. IAV of annual generation and capacity values of wind and solar could impact operations and planning in several ways, e.g. through annual emissions, meeting emission reduction targets, and investment needs to maintain capacity adequacy.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" } ] }, { "doi": "10.1007/S10291-022-01378-1", "year": 2022, "title": "Long-term impact of ionospheric scintillations on kinematic precise point positioning: seasonal and solar activity dependence over Indian low latitudes", "abstract": "The lengthiest GPS observations from a reference station during 20022018 and a colocated scintillation monitoring receiver during 20132018 at Hyderabad, India, are used to analyze the degradation in kinematic precise point positioning (KPPP) due to ionospheric irregularities. The GipsyX software is employed to estimate the KPPP of the reference station and the residuals for each coordinate are computed against the monthly mean values of the daytime observations. The results establish the long-term variability of the residuals of KPPP under the climatological and event-specific effect of the post-sunset equatorial plasma bubbles (EPBs). The extreme post-sunset fluctuations in the residuals during a few quiet and disturbed nights obtained from the 18 years of continuous observations are emphasized. The outstanding and persistent patterns in the residuals are majorly found during extended post-sunset hours with striking seasonal contrast. The large and rapid fluctuations in the residuals are found to exhibit long-term day-to-day, seasonal, and solar cycle variations, which correspond to the occurrence of the amplitude and phase scintillations. Thus, uniquely, the colocated observations of scintillations corroborate the impact of the simultaneously affected number of satellites (S4 index > 0.17) and indicate the possibility of cycle slips eventually affecting the KPPP solutions. The seasonal climatology of the scintillations is shown to translate over the 3-D position error, which modulates with change in the solar F10.7 cm flux. This study, thus probably for the first time, reports the long-term effect of solar cycle variability on the amplitude of perturbations in KPPP for the solar cycles 23 and 24.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.RSE.2017.09.021", "year": 2018, "title": "MODIS-derived global land products of shortwave radiation and diffuse and total photosynthetically active radiation at 5 km resolution from 2000", "abstract": "Incident shortwave radiation (SW), photosynthetically active radiation (PAR), and diffuse PAR (PARdif) at the land surface drive a multitude of processes related to biosphere-atmosphere interactions and play a critical role in the Earth climate system. Previous global solar radiation products were spatially coarse (>50-km resolution) or temporally short (a few years), which hindered scaling-up ground based observations of the land surface processes into regional, continental, and global scales across multiple time scales. Here, we report Breathing Earth System Simulator (BESS) SW, PAR, and PARdif products over the global land surface at a 5km resolution with 4day intervals between 2000 and 2016. We combined an atmospheric radiative transfer model with an artificial neural network (ANN) to compute SW, PAR, and PARdif. A series of MODerate Resolution Imaging Spectroradiometer (MODIS) atmosphere and land products were used as inputs to run the ANN. We test the performance of the products using data from 158 (SW), 77 (PAR), and 22 (PARdif) stations collected in the Baseline Surface Radiation Network (BSRN) and flux tower networks, which covered a range of climatic zones from polar to tropical zones. BESS had strong linear relationships with in-situ SW data (R2=0.95, relative bias=2.3%), PAR (R2=0.94, relative bias=1.7%), and PARdif (R2=0.84, relative bias=0.2%). BESS captured the interannual variability of SW at both the site (a majority of long-term BSRN sites) and continental levels. Over the study period, global annual SW, PAR, and PARdif values did not show any dimming or brightening trends, although these trends appeared at regional levels, e.g. dimming in India. Mean annual SW over the global land surface was 184.8Wm2 (875ZJyr1, zetta=1021); 46% of SW was partitioned to PAR, which was further split into direct (59%) and diffuse (41%) components. The developed products will be useful in solar energy harvesting research and will improve water, carbon, and energy flux estimates of terrestrial ecosystems from local to the global scales.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1109/ACCESS.2022.3168140", "year": 2022, "title": "Operation and Maintenance Decision Support System for Photovoltaic Systems", "abstract": "Operation and maintenance (O&M) and monitoring strategies are important for safeguarding optimum photovoltaic (PV) performance while also minimizing downtimes due to faults. An O&M decision support system (DSS) was developed in this work for providing recommendations of actionable decisions to resolve fault and performance loss events. The proposed DSS operates entirely on raw field measurements and incorporates technical asset and financial management features. Historical measurements from a large-scale PV system installed in Greece were used for the benchmarking procedure. The results demonstrated the financial benefits of performing mitigation actions in case of near zero power production incidents. Stochastic simulations that consider component malfunctions and failures exhibited a net economic gain of approximately 4.17 /kW/year when performing O&M actions. For an electricity price of 59.98 /MWh, a minimum of 8.4% energy loss per year is required for offsetting the annualized O&M cost value of 7.45 /kW/year calculated by the SunSpec/National Renewable Energy Laboratory (NREL) PV O&M Cost Model.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.5194/AMT-11-4373-2018", "year": 2018, "title": "Reduction in 317\u2013780 nm radiance reflected from the sunlit Earth during the eclipse of 21 August 2017", "abstract": "Abstract. Ten wavelength channels of calibrated radiance image data from the sunlit Earth are obtained every 65 min during Northern Hemisphere summer from the EPIC (Earth Polychromatic Imaging Camera) instrument on the DSCOVR (Deep Space Climate Observatory) satellite located near the EarthSun Lagrange 1 point (L1), about 1.5 million km from the Earth. The L1 location permitted seven observations of the Moon's shadow on the Earth for about 3 h during the 21 August 2017 eclipse. Two of the observations were timed to coincide with totality over Casper, Wyoming, and Columbia, Missouri. Since the solar irradiances within five channels (i=388, 443, 551, 680, and 780 nm) are not strongly absorbed in the atmosphere, they can be used for characterizing the eclipse reduction in reflected radiances for the Earth's sunlit face containing the eclipse shadow. Five channels (i=317.5, 325, 340, 688, and 764 nm) that are partially absorbed in the atmosphere give consistent reductions compared to the non-absorbed channels. This indicates that cloud reflectivities dominate the 317.5780 nm radiances reflected back to space from the sunlit Earth's disk with a significant contribution from Rayleigh scattering for the shorter wavelengths. An estimated reduction of 10 % was obtained for spectrally integrated radiance (387 to 781 nm) reflected from the sunlit Earth towards L1 for two sets of observations on 21 August 2017, while the shadow was in the vicinity of Casper, Wyoming (42.8666 N, 106.3131 W; centered on 17:44:50 UTC), and Columbia, Missouri (38.9517 N, 92.3341 W; centered on 18:14:50 UTC). In contrast, when non-eclipse days (20 and 23 August) are compared for each wavelength channel, the change in reflected light is much smaller (less than 1 % for 443 nm compared to 9 % (Casper) and 8 % (Columbia) during the eclipse). Also measured was the ratio REN(i) of reflected radiance on adjacent non-eclipse days divided by radiances centered in the eclipse totality region with the same geometry for all 10 wavelength channels. The measured REN(443 nm) was smaller for Columbia (169) than for Casper (935), because Columbia had more cloud cover than Casper. REN(i) forms a useful test of a 3-D radiative transfer models for an eclipse in the presence of optically thin clouds. Specific values measured at Casper with thin clouds are REN(340 nm) = 475, REN(388 nm) = 3500, REN(443 nm) = 935, REN(551 nm) = 5455, REN(680 nm) = 220, and REN(780 nm) = 395. Some of the variability is caused by changing cloud amounts within the moving region of totality during the 2.7 min needed to measure all 10 wavelength channels.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2020EA001527", "year": 2021, "title": "A Machine Learning Technique for Spatial Interpolation of Solar", "abstract": "This study applies statistical methods to interpolate missing values in a data set of radiative energy fluxes at the surface of Earth. We apply Random Forest (RF) and seven other conventional spatial interpolation models to a global Surface Solar Radiation (SSR) data set. We apply three categories of predictors: climatic, spatial, and time series variables. Although the first category is the most common in research, our study shows that it is actually the last two categories that are best suited to predict the response. In fact, the best spatial variable is almost 40 times more important than the best climatic variable in predicting SSR. Furthermore, the 10 fold cross validation shows that the RF has a Mean Absolute Error (MAE) of 10.2 Wm\u22122 and a standard deviation of 1.5 Wm\u22122. On the other hand, the average MAE of the conventional interpolation methods is 21.3 Wm\u22122, which is more than twice as large as the RF method, in addition to an average standard deviation of 6.4 Wm\u22122, which is more than four times larger than the RF standard deviation. This highlights the benefits of using machine learning in environmental research.", "labels": [ { "id": 17, "name": "Validation" } ] }, { "doi": "10.1038/S41598-018-32291-8", "year": 2018, "title": "Effects of soiling on photovoltaic (PV) modules in the Atacama Desert", "abstract": "Soiling by dry deposition affects the power output of photovoltaic (PV) modules, especially under dry and arid conditions that favor natural atmospheric aerosols (wind-blown dust). In this paper, we report on measurements of the soiling effect on the energy yield of grid-connected crystalline silicon PV modules deployed in five cities across a north-south transect of approximately 1300 km in the Atacama Desert ranging from latitude 18S to latitude 30S. Energy losses were assessed by comparing side-by-side outputs of four co-planar PV modules. Two of the PV modules of the array were kept clean as a control, while we allowed the other two to naturally accumulate soiling for 12 months (from January 2017 to January 2018). We found that the combination of high deposition rates and infrequent rainfalls led to annual energy losses that peaked at 39% in the northern coastal part of the desert. In contrast, annual energy losses of 3% or less were measured at relatively high-altitude sites and also at locations in the southern part of the desert. For comparison, soiling-induced annual energy losses of about 7% were measured in Santiago, Chile (33S), a major city with higher rainfall frequency but where urban pollution plays a significant role.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 7, "name": "Energy Production/Use" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1002/JOC.6634", "year": 2021, "title": "Newly collected data across Alaska reveal remarkable biases in solar radiation products", "abstract": "AbstractData on surface solar radiation are scarce in highlatitude regions, and few studies have evaluated the performance of reanalysis products in estimating solar radiation in those regions. Here, an extensive solar radiation dataset is compiled from 98 stations across Alaska to evaluate 11 different surface solar radiation products (seven reanalysis and four observationderived). No product can capture all aspects of the groundbased observations, and there is ample room for improvement; root mean square errors (RMSEs) of daily, monthly, and annual average comparisons of the products against observations are 3865, 1939, and 1117 Wm2, respectively. ERA5, MERRA2, and ERAInterim performed the best in Alaska. Daily records from all products show large RMSEs of 60108 Wm2 during MayJuly, equivalent to 3055% of the observed solar radiation during this season. The sparseness of Alaskan observations, cloud cover, and algorithm issues may be potential sources of bias.", "labels": [ { "id": 17, "name": "Validation" }, { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1029/2009JD013625", "year": 2011, "title": "Radiative forcing under mixed aerosol conditions", "abstract": "The mixture of mineral dust with biomass burning or urban-industrial aerosols presents significant differences in optical properties when compared to those of the individual constituents, leading to different impacts on solar radiation levels. This effect is assessed by estimating the direct radiative forcing (\u0394F) of these aerosols from solar flux models using the radiative parameters derived from the Aerosol Robotic Network (AERONET). These data reveal that, in oceanic and vegetative covers (surface albedo (SA) < 0.30), the aerosol effect at the top of atmosphere (TOA) is always cooling the Earth-atmosphere system, regardless of the aerosol type. The obtained average values of \u0394F range between -27 \u00b1 15 Wm-2 (aerosol optical depth (AOD) at 0.55 \u03bcm, 0.3 \u00b1 0.3) for mineral dust mixed with urban-industrial aerosols, registered in the East Asia region, and -34 \u00b1 18 Wm-2 (AOD = 0.8 \u00b1 0.4) for the mixture of the mineral dust and biomass burning particles, observed in the Central Africa region. In the intermediate SA range (0.30-0.50) the TOA radiative effect depends on the aerosol absorption properties. Thus, aerosols with single scattering albedo at 0.55 \u03bcm lower than \u223c0.88 lead to a warming of the system, with \u0394F of 10 \u00b1 11 Wm-2 for the mixture of mineral dust and biomass burning. Cases with SA > 0.30 are not present in East Asia region. At the bottom of atmosphere (BOA) the maximum \u0394F values are associated with the highest AOD levels obtained for the mixture of mineral dust and biomass burning aerosols (-130 \u00b1 44 Wm-2 with AOD = 0.8 \u00b1 0.4 for SA < 0.30).", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" }, { "id": 8, "name": "Environmental Impacts" } ] }, { "doi": "10.1088/2515-7620/AC7A25", "year": 2022, "title": "Mapping potential surface contributions to reflected solar radiation", "abstract": "Abstract\r\n Modifying Earths albedo is one of the strategies considered to reduce its energy imbalance and slow global warming by reflecting solar energy. Atmospheric contributions to reflected solar radiation through stratospheric aerosols or cloud brightening have received considerable attention; however, the efficacy of surface interventions is less understood. We address this gap by estimating the potential for surface contributions to reflected solar radiation at approximately 30 km resolution using a simple radiative transfer model. Long-term average annual-mean incoming and outgoing top-of-atmosphere and surface solar fluxes are input to determine atmospheric shortwave optical properties (i.e., transmittance, absorptance, and reflectance), which can be used with surface albedo to estimate surface-reflected outgoing solar radiation. A comparison of reanalysis- and satellite-based input datasets shows good agreement. The results indicate global annual-mean surface-reflected outgoing solar radiation potential of 109 Wm-2, nearly a factor of five larger than the actual value, and local areas where it could be increased above 200 Wm-2 with surface albedo enhancement. Regions with particularly strong potential include Andean South America, the Middle East, southwestern North America, southwestern Africa, Australia, and the sub-equatorial tropical oceans. Future research could extend the methods to account for seasonal variations and the potential to mitigate extreme heat events in particular.", "labels": [ { "id": 16, "name": "Sun-Earth Interactions" } ] }, { "doi": "10.1016/J.ACTAASTRO.2016.03.015", "year": 2016, "title": "On the influence of impact effect modelling for global asteroid impact risk distribution", "abstract": "The collision of an asteroid with Earth can potentially have significant consequences for the human population. The European and United States space agencies (ESA and NASA) maintain asteroid hazard lists that contain all known asteroids with a non-zero chance of colliding with the Earth in the future. Some software tools exist that are, either, capable of calculating the impact points of those asteroids, or that can estimate the impact effects of a given impact incident. However, no single tool is available that combines both aspects and enables a comprehensive risk analysis. The question is, thus, whether tools that can calculate impact location may be used to obtain a qualitative understanding of the asteroid impact risk distribution. To answer this question, two impact risk distributions that control for impact effect modelling were generated and compared. The Asteroid Risk Mitigation Optimisation and Research (ARMOR) tool, in conjunction with the freely available software OrbFit, was used to project the impact probabilities of listed asteroids with a minimum diameter of 30m onto the surface of the Earth representing a random sample (15% of all objects) of the hazard list. The resulting 261 impact corridors were visualised on a global map. Furthermore, the impact corridors were combined with Earth population data to estimate the simplified risk (without impact effects) and advanced risk (with impact effects) associated with the direct asteroid impacts that each nation faces from present to 2100 based on this sample. The relationship between risk and population size was examined for the 40 most populous countries and it was apparent that population size is a good proxy for relative risk. The advanced and simplified risk distributions were compared and the alteration of the results based on the introduction of physical impact effects was discussed. Population remained a valid proxy for relative impact risk, but the inclusion of impact effects resulted in significantly different risks, especially when considered at the national level. Therefore, consideration of physical impact effects is essential in estimating the risk to specific nations of the asteroid threat.", "labels": [ { "id": 17, "name": "Validation" } ] } ]