es_qa_sq2format_train.v2.json

{"version": "v2.0", "data": [{"title": "Environmental degradation", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What issue causes environmental degradation?", "id": "0", "answers": [{"text": "Pollution", "answer_start": 51}]}, {"is_impossible": false, "question": "What is Pollution is created from?", "id": "1", "answers": [{"text": "vehicle emissions, agricultural runoff, chemical release, and poorly managed harvesting of natural resources", "answer_start": 162}]}, {"is_impossible": false, "question": "What depletes ecosystems?", "id": "2", "answers": [{"text": "Environmental degradation ", "answer_start": 4}]}, {"is_impossible": true, "question": "Which pollution source increases phosphorus and nitrite levels? ", "id": "3", "answers": []}, {"is_impossible": true, "question": "What is a pollution source?", "id": "4", "answers": [], "plausible_answers": [{"text": "A variety of sources", "answer_start": 130}]}], "context": "The environmental degradation depletes ecosystems. Pollution is the main cause of environmental degradation. Pollution comes from a variety of sources, including vehicle emissions, agricultural runoff, chemical release, and poorly managed harvesting of natural resources."}]}, {"title": "mesoscale forecasting, severe thunderstorms", "paragraphs": [{"qas": [{"is_impossible": false, "question": "How would you characterize HSLC environments across the West?", "id": "5", "answers": [{"text": "Drier lower troposphere and a surface triple-point or upslope setup", "answer_start": 751}]}, {"is_impossible": false, "question": "Where do the majority of significant tornadoes and winds occur?", "id": "6", "answers": [{"text": "Southeast", "answer_start": 682}]}, {"is_impossible": false, "question": "What is similar across all regions?", "id": "7", "answers": [{"text": "Middle and upper-tropospheric synoptic scale features", "answer_start": 1028}]}, {"is_impossible": true, "question": "When do high-shear, low-CAPE environments tend to occur?", "id": "8", "answers": []}, {"is_impossible": true, "question": "What is a surface triple-point?", "id": "9", "answers": [], "plausible_answers": [{"text": "Upslope setup", "answer_start": 805}]}], "context": "High-shear, low-CAPE (HSLC) severe convection remains a forecasting challenge across time scales ranging from days to minutes in advance. These environments compose a majority of the EF1 or greater tornado and significant wind report population during the cool season, especially during the overnight hours. This population corresponds to time periods when climatological conditions are generally unfavorable for severe convection and, accordingly, the performance of severe weather watches and warnings is notably decreased. HSLC severe convection occurs across all regions of the contiguous United States; however, the majority of significant tornadoes and winds occur within the Southeast. Across the West, HSLC environments are characterized by a drier lower troposphere and a surface triple-point or upslope setup, which suggests they may be fundamentally dissimilar from HSLC events in the East that are typically associated with low lifted condensation levels and occur in the warm sector or along a cold front. However, middle and upper-tropospheric synoptic scale features across all regions are fairly similar, with strong forcing for ascent exhibited at all levels. "}]}, {"title": "hurricane eyewall mesovortex dynamics", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What was the most significant finding of the study?", "id": "10", "answers": [{"text": "the arrangement of \u03b6 and w maxima within each MV progresses in a common fashion as the MVs are located in various regions of the hurricane eyewall", "answer_start": 51}]}, {"is_impossible": false, "question": "For this case, did mesovortices (MVs) form after the TC made landfall?", "id": "11", "answers": [{"text": "after", "answer_start": 199}]}, {"is_impossible": false, "question": "What occurred that changed the processes that generate and maintain mesovortices (MVs)?", "id": "12", "answers": [{"text": "the storm moved inland and began weakening", "answer_start": 446}]}, {"is_impossible": true, "question": "What is the typical arrangement of potential vorticity (\u03b6) and vertical motion (w) maxima for tropical cyclone eyewall mesovortices (MVs)?", "id": "13", "answers": []}, {"is_impossible": true, "question": "Do mesovortices (MVs) generated well after landfall exhibit the same kinematic signatures as MVs that formed well prior to landfall?", "id": "14", "answers": []}], "context": "The most significant finding of this study is that the arrangement of \u03b6 and w maxima within each MV progresses in a common fashion as the MVs are located in various regions of the hurricane eyewall. After Ike's center crossed the Bolivar Peninsula, MVs continued to persist and even initiate. The MVs forming after landfall (0700 UTC) are denoted inland MVs, or iMVs. Interaction with the coastline and changes to the hurricane boundary layer as the storm moved inland and began weakening would have modified the processes generating and maintaining the MVs (e.g., Wu et al. 2009). Early on, iMVs exhibit characteristics akin to MVs that formed while at least half of the eyewall was still over the Gulf of Mexico, but as Ike moves inland obvious departures from these persistent kinematic arrangements occur."}]}, {"title": "ground validation of satellite-based precipitation observations", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What additional parameters are used to evaluate time lag in this study?", "id": "15", "answers": [{"text": "Dm and Ze", "answer_start": 394}]}, {"is_impossible": false, "question": "Why are DPR and GMI observations extracted at heights at least 1 km below the melting level and above the LCFH?", "id": "16", "answers": [{"text": "to avoid ground clutter contamination", "answer_start": 576}]}, {"is_impossible": false, "question": "Is a consistent interval of time lag observed in the present case?", "id": "17", "answers": [{"text": "no ", "answer_start": 1019}]}, {"is_impossible": true, "question": "Did the satellite-based precipitation estimates in this case compare well to the ground-based observations?", "id": "18", "answers": []}, {"is_impossible": true, "question": "What amount of time lag fall delay was observed in the Tan et al. (2008) study?", "id": "19", "answers": [], "plausible_answers": [{"text": "between 0 and 30 min", "answer_start": 1070}]}], "context": "Comparing instantaneous GPM sensor precipitation measurements above the surface with ground observations should involve some time lag due to fall delay. Therefore, this study conducts a time lag comparison of R to surface platforms, similar to past studies (e.g., Amitai et al. 2012; Tan et al. 2018), but with two additional validation parameters that are crucial to GPM algorithm developers (Dm and Ze). GPM DPR and DPR/GMI CORRA data are extracted at least 1 km below the melting level to avoid partially melted hydrometeors and above the lowest clutter-free height (LCFH) to avoid ground clutter contamination. Quality controlled NPOL observations, high-temporal- and high-spatial-resolution MRR, disdrometer, and rain gauge data are used to evaluate the performance of the algorithms. The time lag investigation indicates maximum correlation coefficient (r) values [minimum bias and normalized bias (NB)] are between overpass time and 30 min after overpass. Similar to past findings by Tan et al. (2018), there is no consistent value of time lag, but it does vary between 0 and 30 min after the overpass. Therefore, GPM DPR, DPR/GMI CORRA, and GPROF retrievals are compared with the mean between 2 and 8 min after overpass-time ground-based measurements."}]}, {"title": "Asian Sand and Dust Storms", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What time of the year do asian dust storms frequently occur?", "id": "20", "answers": [{"text": "nearly every spring", "answer_start": 246}]}, {"is_impossible": false, "question": "Can airborne dust from asia reach US?", "id": "21", "answers": [{"text": "Asian dust could transport across the Pacific Ocean and reach as far as the western U.S.", "answer_start": 907}]}, {"is_impossible": false, "question": "What factors contribute in the formation of dust storms?", "id": "22", "answers": [{"text": "weather system, short-term precipitation, soil moisture, and extent of deforestation, long-term increased drought, land use/land coverage changes, as well as other human activities.", "answer_start": 1383}]}, {"is_impossible": true, "question": "Can you monitor asian dust storms using GOES sensor?", "id": "23", "answers": []}, {"is_impossible": true, "question": "what is the only way to monitor airborne dust storms?", "id": "24", "answers": [], "plausible_answers": [{"text": "Satellite remote sensing", "answer_start": 358}]}], "context": "Asian sand and dust storms (SDSs) are a very important environmental issue, and one of the major natural hazards in the Mongolian regions and northern China [1], [2]. Major dust storms, usually from the Mongolian desert, occur over these regions nearly every spring. Due to the limited ground environmental and climatic observations in the relevant regions, satellite remote sensing (RS) has become an important approach to detect dust storms in Asia. As we know, RS can not only provide initial parameters for model simulations but also be used for verification and validation of model simulations [3], [4]. Multi satellite observations such as TOMS, SeaWiFS, AVHRR, and the Chinese FY-1C/D series have been used in Asian dust storm monitoring. But at the present time, RS of dust storms can only provide near global horizontal coverage with limited vertical resolutions [5]. Early research has shown that Asian dust could transport across the Pacific Ocean and reach as far as the western U.S.[6]. Several international collaborative programs, such as the Aerosol Characterization Experiment (ACE)-Asia and Asian Dust Network (AD-Net), have been established [1]. The aerosol properties over the ocean are also evaluated by Moderate Resolution Imaging Spectroradiometer (MODIS) during ACE-Asia[7]. The dust storm formation mechanisms are very complex; they are related to the local weather system, short-term precipitation, soil moisture, and extent of deforestation, long-term increased drought, land use/land coverage changes, as well as other human activities. "}]}, {"title": "Dust Spectrum Characterization Analysis", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Which MODIS bands have spatial resolution of 500 m?", "id": "25", "answers": [{"text": "bands 3-7", "answer_start": 83}]}, {"is_impossible": false, "question": "Which MODIS spectral band has the maximum reflectance for sand?", "id": "26", "answers": [{"text": "band 7 (2.13 \u03bcm)", "answer_start": 1017}]}, {"is_impossible": false, "question": "Where can you find spectral signatures for different materials useful for remote sensing?", "id": "27", "answers": [{"text": "Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectrum library", "answer_start": 277}]}, {"is_impossible": true, "question": "Can a single MODIS spectral band can identify airborne dust?", "id": "28", "answers": []}, {"is_impossible": true, "question": "Is it possible to distinguish between airborne dust and cirrus clouds using MODIS data?", "id": "29", "answers": [], "plausible_answers": [{"text": "This spectrum characteristic of sand and soil makes it easy to distinguish SDS from cloud, which has the highest reflectance in MODIS band 3.", "answer_start": 1034}]}], "context": "MODIS has three different spatial resolutions including 250 m (bands 1-2), 500 m (bands 3-7), and the 1-km (bands 8-36). There are a total of 20 solar reflectance bands (SRBs) (1-19 and 26) from 0.41-2.13 \u03bcm [11]. There are spectral signatures for hundreds of materials in the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) spectrum library, which is used as a reference for material identification [12]. We analyzed the spectral signatures of sand, grass, soil, urban residential,and water in the ASTER spectrum library and cloud signatures from J. Dozier (http://www.brenucsb.edu/fac_staff/fac/dozier/Talks/RSS.mht!RSS_files/frame.htm). The reflectance of water and ice cloud, sand, grass, soil, urban residential, and water, and the locations of MODIS SRB bands (0.4-2.5 \u03bcm), are shown in Fig. 1. It is clear that the reflectance of dust (sand and soil)generally increases with wavelength between 0.4 and 2.5 \u03bcm with a minimum value in MODIS band 3 (0.469 \u03bcm) and a maximum value in MODIS band 7 (2.13 \u03bcm). This spectrum characteristic of sand and soil makes it easy to distinguish SDS from cloud, which has the highest reflectance in MODIS band 3. Therefore, SDS features can be discerned using the dust spectrum characteristics as described here."}]}, {"title": "Drought, Precipitation Reconstruction", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What impacts historical precipitation observations?", "id": "30", "answers": [{"text": "non-climatic biases", "answer_start": 57}]}, {"is_impossible": false, "question": "When do most problems of undercounted precipitation occur in historical precipitation records?", "id": "31", "answers": [{"text": "cold season", "answer_start": 760}]}, {"is_impossible": false, "question": "Why was this study restricted to the warm season?", "id": "32", "answers": [{"text": "Most of the undercount problem occurs in the cold season", "answer_start": 715}]}, {"is_impossible": true, "question": "What does the estimate of effective moisture not account for?", "id": "33", "answers": []}, {"is_impossible": true, "question": "What threshold value was used to minimize the undercount biases in the precipitation data during the warm season?", "id": "34", "answers": [], "plausible_answers": [{"text": "careful screening and selection of the best available records", "answer_start": 1072}]}], "context": "Historical precipitation observations can be impacted by non-climatic biases that must be assessed and minimized. Problems with 19th century precipitation data can include conversion of snowfall to liquid equivalent, high placement of the rain gauge that can cause lower liquid accumulation with higher wind speed, infrequent observation of the precipitation gauge which can allow water loss due to evaporation, changes in the physical environment around the gauge (e.g., tree growth, building construction), and changes in instrumentation (Larson and Peck 1974; Mock 1991, 2000; Daly et al. 2007). These problems can lead to undercounted precipitation, which is commonly found in historical precipitation records. Most of the undercount problem occurs in the cold season (Larson and Peck 1974; Mock 1991, 2000), and therefore, this study was restricted to the warm season (April-August). Poor gauge exposure and observer inattentiveness to small rain events can impact the quality of the precipitation data even in the warm season, but these problems can be minimized by careful screening and selection of the best available records."}]}, {"title": "Wildland fires", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What is a major source of PM2.5 emissions in the US?", "id": "35", "answers": [{"text": "Wildland fires", "answer_start": 0}]}, {"is_impossible": false, "question": "What type of wildland fires dominate in the southeastern US?", "id": "36", "answers": [{"text": "human-ignited prescribed burns or agricultural burns", "answer_start": 340}]}, {"is_impossible": false, "question": "When do most wildland fire emissions occur in the western US?", "id": "37", "answers": [{"text": "in the summer", "answer_start": 687}]}, {"is_impossible": true, "question": "What trace gases do wildland fires emit?", "id": "38", "answers": []}, {"is_impossible": true, "question": "What are the health effects of emissions from wildland fires?", "id": "39", "answers": []}], "context": "Wildland fires are a major source of particulate matter with diameters smaller than 2.5 \u03bcm (PM2.5) in the United States (US). According to the Environmental Protection Agency (EPA) 2011 National Emissions Inventory (NEI), wildland fires emit 25% of primary PM 2.5 in the US.1 In the southeastern US, wildland fire burn area is dominated by human-ignited prescribed burns or agricultural burns, while in the western US, \u223c70% of wildland fire burned area is from lightning-ignited fires. 2 In both regions, burned area is heavily tied to environmental conditions and could be similarly impacted by changes in climate.2 In the western US, most wildland fire burned area and emissions occur in the summer, and the occurrence of wildland fires varies greatly from year to year. Annual area burned by wildland fires in the US can differ by a factor of 3 or more from year to year. 3 In the western US, the interannual variability in wildland fire occurrence drives interannual variability in summer aerosol concentrations.4,5 Despite their episodic nature and high interannual variability, wildland fires can have significant negative impacts on air quality and public health in the western US, especially in high fire years."}]}, {"title": "Severe weather", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Which are important factors for high-impact weather events?", "id": "40", "answers": [{"text": "Gust fronts and other wind discontinuities.", "answer_start": 164}]}, {"is_impossible": false, "question": "What is the use of scatterometers?", "id": "41", "answers": [{"text": "Scatterometers have the ability to retrieve the surface winds", "answer_start": 761}]}, {"is_impossible": false, "question": "How is the wind and precipitation related?", "id": "42", "answers": [{"text": "The authors found a significant correlation between the wind speed and precipitation", "answer_start": 1506}]}, {"is_impossible": true, "question": "What is the effect of rain on scatterometer measurements?", "id": "43", "answers": []}, {"is_impossible": true, "question": "What is the name of a ku-band scatterometer?", "id": "44", "answers": [], "plausible_answers": [{"text": "QuikSCAT", "answer_start": 1322}]}], "context": "Unlike continental storms that exhibit strong diurnal variability in energy exchanges, maritime storms have less variable fluxes that reach lower peaks. Therefore, gust fronts and other wind discontinuities are of key importance in high-impact weather events, as they focus moisture convergence and lead to the development of new precipitation systems (Forbes & Wakimoto, 1983; Weaver & Nelson, 1982; Wilson & Schreiber, 1986; Wilson et al., 1992). For example, the propagation of the systems is achieved by triggering new storms in neighbor regions once the cold pool has formed, thus setting off a chain reaction. This feature, which forms at lower levels, represents the collective outflow of individual convective cells of an organized MCS (Corfidi, 2003). Scatterometers have the ability to retrieve the surface winds and therefore are adequate to explore such surface features. Over the last decades, satellite scatterometers have been providing valuable sea surface wind field information. Due to the paucity of in situ observations over ocean regions, the association between these precipitating systems and mesoscale surface wind features has been poorly explored. Back and Bretherton (2005) examined the daily relationship between wind speed and precipitation in the Pacific Intertropical Convergence Zone using QuikSCAT wind vectors and precipitation derived by the Special Sensor Microwave Imager and Tropical Rainfall Measuring Mission Microwave Imager satellite passive microwave retrievals. The authors found a significant correlation between the wind speed and precipitation, which became more robust in moister conditions. Although the near-surface wind speed explained a small fraction of the daily rainfall variability, it can be used as a useful tool to explore how surface forcing modulates tropical convection. Other studies have also revealed a relationship between precipitation characteristics and surface wind features (Bordoni et al., 2004; Elsaesser & Kummerow, 2013), but such studies are rare."}]}, {"title": "Tropical Cyclones", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Which area of the cyclone has the highest rainfall when the cyclone's translation speed increases?", "id": "45", "answers": [{"text": "Forward sector of the TC", "answer_start": 1050}]}, {"is_impossible": false, "question": "Where do cyclones originate more frequently out of Arabian Sea and the Bay of Bengal?", "id": "46", "answers": [{"text": "Bay of Bengal", "answer_start": 285}]}, {"is_impossible": false, "question": "Which cyclone's sector or quadrant experiences the most rainfall in the North Indian Ocean ?", "id": "47", "answers": [{"text": "Left-forward sector", "answer_start": 562}]}, {"is_impossible": true, "question": "Why does the Bay of Bengal experience more cyclones than the Arabian Sea?", "id": "48", "answers": []}, {"is_impossible": true, "question": "Why there is a calm weather or no rainfall at the core of the cyclone ?\u00a0", "id": "49", "answers": []}], "context": "Using Tropical Rainfall Measuring Mission rain estimates the relationship between rainfall and intensity changes in tropical cyclones (TCs) over the North Indian Ocean (NIO) based on 71 TCs during 1997-2017 is investigated. The axisymmetric analyses revealed that climatologically the Bay of Bengal (BoB) TCs produce extremely heavy rainfall (~9-10 mmhr\u22121) and Arabian Sea TCs produce very heavy rainfall (~7-8 mmhr\u22121 ) in the storm inner core region (0-100 km). The inner-core region receives three times higher rainfall than the outer region (100-300 km). The left-forward sector experiences the maximum rainfall for any TC intensity over the NIO basin. A significant increase (decrease) in the rain rate is seen during normal to rapid intensification (weakening) phase. A notable decrease in rainfall of ~4.3 mmhr\u22121 is observed for the rapidly weakening TCs. Slow- moving TCs are generally stronger and produce heavy rainfall (2-4 mmhr\u22121 ) up to ~300 km storm radius. As the translation speed increases, rainfall gradually shifts from rear to the forward sector of the TC. The asymmetry (wavenumber-1) in TC rainfall structures revealed that rainfall maximum is located in the left- forward sector for almost all intensity stages. The amplitude of wave number-1 asymmetry in TC rainfall shows cyclonic shift as the TC intensity increases and is particularly prevalent in the BoB region. These analyses would be helpful as a baseline for evaluating the performance of numerical models and to identify the vulnerable areas for TC heavy rainfall."}]}, {"title": "Tropical Cyclone", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What's values of Tropical Cyclone Heat Potential ( TCHP) favors the most for intensification of cyclones ?", "id": "50", "answers": [{"text": "40-80 kJ/cm", "answer_start": 601}]}, {"is_impossible": false, "question": "Which sector of the tropical cyclone experiences significant changes in TCHP anomaly (TCHPA) as the intensity increases.", "id": "51", "answers": [{"text": "Right-rear sector ", "answer_start": 830}]}, {"is_impossible": false, "question": " Which season sees a greater amount of cooling for cyclones?", "id": "52", "answers": [{"text": "pre-monsoon season", "answer_start": 1710}]}, {"is_impossible": true, "question": "How does TCHP change affect the cyclone intensity change?", "id": "53", "answers": []}, {"is_impossible": true, "question": "Why slow moving tropical cyclone produce maximum TCHPA cooling in the rear sector ?\u00a0", "id": "54", "answers": []}], "context": "The Bay of Bengal (BoB) exhibits notable seasonal variations in tropical cyclone heat potential (TCHP), barrier layer thickness (BLT) and sea-surface temperature (SST). These parameters also undergo profound changes in the presence of tropical cyclones (TCs). The composite structures of these ocean parameters as a function of the season of TC formation, intensity, and translation speed are unknown and are developed in the present study. Composite structures are examined based on 1,222 instantaneous samples from 83 TCs during 2003-2016 using INCOIS-GODAS anal- yses. A BLT of 10-30 m and TCHP of 40-80 kJ/cm2 favours TC intensification in the central BoB. The multivariate regression of BLT and TCHP appears to be bet- ter for TC intensity up to 64 knots and is highly underestimated for the stronger TCs (>64 knots). The TC right-rear sector experiences significant changes in TCHP anomaly (TCHPA) as the intensity increases. The TCHPA ranges \u223c10-15, \u223c20-25 and \u223c25-30 kJ/cm2 when a TC is at Cyclone Storm (CS), Severe Cyclonic Storm (SCS) and Very SCS (VSCS) stages respectively. The maximum TCHPA is gen- erally aligned along the TC track during the post-monsoon season. Slow-moving TCs produce maximum TCHPA cooling of \u223c20 kJ/cm2 within 250 km storm radius in the rear sector, while it is less and away from the storm centre for normal and fast-movers. The seasonal changes showed opposite relations between BLT and TCHP from pre- to post-monsoon seasons during the TC intensification. TC-induced SST cooling is maximum (\u223c0.5-1.2 \u25e6C) in the inner core for the strong (VSCS and above) and slow-moving TCs. The cooling decreases with an increase in the transla- tion speed and is more pronounced in the pre-monsoon season. This study provides a baseline to verify and understand the limitations of the models, and also develop a climatological perspective of BoB TCs."}]}, {"title": "Tropical Cyclones", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What cyclone intensity should the model be initialized at to obtain the more accurate forecast? ", "id": "55", "answers": [{"text": "stronger intensity (SCS and VSCS) stages", "answer_start": 962}]}, {"is_impossible": false, "question": "Where does the model produce the least error\u2014the inner or outer core of the cyclone?", "id": "56", "answers": [{"text": "TC environment (200-400 km)", "answer_start": 1181}]}, {"is_impossible": false, "question": "How much of the RMSE has been decreased following the CRA correction?", "id": "57", "answers": [{"text": "3-15%", "answer_start": 1999}]}, {"is_impossible": true, "question": "What is the difference between the pattern and displacement error?", "id": "58", "answers": []}, {"is_impossible": true, "question": " Why the landfalling tropical cyclones (TCs) pose a severe threat to the coastal communities over the North Indian Ocean (NIO) region?", "id": "59", "answers": []}], "context": "The hydrological extremes due to the landfalling tropical cyclones (TCs) pose a severe threat to the coastal communities over the North Indian Ocean (NIO) region. Advanced Research Weather Research and Forecasting (ARW) model is obscure in rainfall prediction, while it is extensively evaluated for track and intensity prediction over the NIO. This study focuses on estimating the model rainfall errors based on a total of 280 TC forecast cases from 42 TCs from 2007 to 2018. The model rainfall errors are studied against rain gauge and Tropical Rainfall Measuring Mission (TRMM) data as a function of TC intensity stage and model forecast length. The short-range (24 h) rainfall guidance yields fewer errors than the long-range (48-96 h) forecast when the model is initialized at any TC intensity stage. The root mean square error (RMSE) and bias of ARW rainfall is higher when the model is initialized at weaker intensity (DD or CS) stages than initialized at stronger intensity (SCS and VSCS) stages. The inland rainfall errors increase with forecast lead. The model exhibited higher errors (~2 mm h\u22121) in the inner-core region (0-100 km) and lesser errors (~0.5 mm h\u22121) in the TC environment (200-400 km). The ARW model replicates the observed radial profiles of rainfall up to 400 km with 2-5 mm h\u22121 overestimation at different intensity stages. Rainfall error decomposition of contiguous rain area (CRA) analysis indicates that the pattern errors contribute the maximum (~50%) to the total error, followed by the displacement error (~35%). In comparison, the volume and rotational errors are less (10% and 2%, respectively). The mean CRA horizontal shift in rainfall decreases from weaker to stronger stage initialization. The radial-distance error of categorical rainfall distribution between the ARW model and TRMM is ~ 150-200 km. This error reduced to 20-50 km after correcting the model rainfall for CRA displacement errors. The RMSE of model-rainfall after CRA correction has reduced by 3-15% for any forecast length. This study helps to advance the regional hydrological model's ability by improved model rainfall inputs at 72-96 h lead."}]}, {"title": "Tropical Cyclone", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Which approach relates the NRCS measurements to the surface friction velocity and wind stress?", "id": "60", "answers": [{"text": "Bragg scattering", "answer_start": 172}]}, {"is_impossible": false, "question": "When does the elementary relationship between surface roughness and wind breaks down?", "id": "61", "answers": [{"text": "higher wind regimes", "answer_start": 1234}]}, {"is_impossible": false, "question": "How is the increase of wind speeds approximated to the growth of the wave spectrum?", "id": "62", "answers": [{"text": "By closed-form mathematical functions", "answer_start": 650}]}, {"is_impossible": true, "question": "In what frequency does QuickSCAT operate?", "id": "63", "answers": []}, {"is_impossible": true, "question": "What is an example of scatterometer?", "id": "64", "answers": [], "plausible_answers": [{"text": "QuikSCAT", "answer_start": 953}]}], "context": "The physical modeling of the relationship between sea-surface wind speeds from 5 to 15 m/s and microwave radar backscatter has advanced to a mature area of knowledge [18]. Bragg scattering is the generally accepted interpretation of observations made by scatterometers under these wind conditions and incidence angles typical of a satellite scatterometer. This approach relates the NRCS measurements to the small-scale centimeter-wave spectrum and, thereby, to the surface friction velocity and wind stress. The increase of wind speeds (under low-to-moderate conditions) is then related to the growth of the wave spectrum, which is well approximated by closed-form mathematical functions. For wind-driven seas (and arguably for swell [4]), the aerodynamic roughness can be mapped to geometric roughness (shape) of the surface water waves. For these conditions, there is a relationship between two electromagnetic polarizations (H-pol and V-pol) and the QuikSCAT incident angles, where the NRCS for V-pol clearly exceeds that for H-pol. Therefore, the radar NRCS should be related to sea-surface roughness with terms such as rms wave height (for wind-driven waves) and/or slope, within a certain range of the sea-surface spectrum. For higher wind regimes, additional physical considerations become important, and this elementary relationship between surface roughness and wind (or stress) breaks down. Plant et al. [19] have studied these conditions in depth and suggested more elaborate physical models to explain measurements in higher winds where the H-pol NRCS is higher than predicted by Bragg scattering due to surface features caused by breaking waves and spray."}]}, {"title": "Environmental degradation", "paragraphs": [{"qas": [{"is_impossible": false, "question": "The depletion of landscapes create unfamiliarity and stops the utilization of what?", "id": "65", "answers": [{"text": "resources", "answer_start": 101}]}, {"is_impossible": false, "question": "What is the main cause of environmental degradation?", "id": "66", "answers": [{"text": "pollution", "answer_start": 342}]}, {"is_impossible": false, "question": "Name one source that causes pollution?", "id": "67", "answers": [{"text": "Vehicle emissions", "answer_start": 470}]}, {"is_impossible": true, "question": "Which pollution source causes nitrite and phosphorus levels to exceed?", "id": "68", "answers": []}, {"is_impossible": true, "question": "What pollution source is entirely caused by humans?", "id": "69", "answers": [], "plausible_answers": [{"text": "Agricultural runoff", "answer_start": 489}]}], "context": "The depletion of landscapes creates unfamiliarity to inhabiting populations and stops utilization of resources. Unable to experience the landscape destroys identity, sense of place, disturbs the pristine environment, depletes resources, and extinction of animal populations. An example of an issue that can cause environmental degradation is pollution. Pollution is the emission of a harmful substance into the environment. It comes from a variety of sources, including vehicle emissions, agricultural runoff, accidental chemical release from factories, and poorly managed harvesting of natural resources"}]}, {"title": "Environmental change", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What's primary kind of forest disturbance since 2004?", "id": "70", "answers": [{"text": "D/ND", "answer_start": 530}]}, {"is_impossible": false, "question": "Which estimate has the largest uncertainty, the area estimate of deforestation or that of D/ND?", "id": "71", "answers": [{"text": "D/ND", "answer_start": 530}]}, {"is_impossible": false, "question": "Which has increased more since 2004, deforestation or D/ND?", "id": "72", "answers": [{"text": "D/ND", "answer_start": 530}]}, {"is_impossible": true, "question": "Which sampling design was used for the area estimation?", "id": "73", "answers": []}, {"is_impossible": true, "question": "Which satellite data source was used for the time series analysis?", "id": "74", "answers": []}], "context": "The biennial area estimates allow for evaluation of trends over time in undisturbed, regenerating, and secondary forests (Figure 4). Consistent with previous estimates, deforestation in the Amazon Ecoregion decreased significantly after the implementation of PPCDAm in Brazil in 2004 (Arag\u00e3o et al., 2018; Instituto Nacional de Pesquisas Espaciais Projeto Prodes, 2013; Tyukavina et al., 2017). Before 2004, there was an average of 47,000 km2/biennium of deforestation, which decreased to 25,000 km2/biennium afterwards. However, D/ND remained relatively consistent throughout the study period, and has been the primary kind of forest disturbance since 2004. Of consequence, the proportion of total disturbance attributed to D/ND has been steadily increasing. The only period with more deforestation than D/ND was 2002-2003, in which D/ND consisted of 59% of the area of deforestation. For the other periods, D/ND accounted for 102%-354% of the area of deforestation. Because deforestation often occurred after D/ND and D/ND could occur multiple times at the same location, the difference between the geographic area that was at some point deforested (383,000 \u00b1 15,500 km2 ) and the area of forest affected only by D/ND (366,300 \u00b1 20,500 km2) was not statistically significant (\u03b1 = 0.05)."}]}, {"title": "environmental statistics", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What are strata?", "id": "75", "answers": [{"text": "discrete, mutually exclusive subsets", "answer_start": 50}]}, {"is_impossible": false, "question": "What are two purposes of a stratification? ", "id": "76", "answers": [{"text": "when the strata are of interest for reporting results", "answer_start": 490}]}, {"is_impossible": false, "question": "What are two common attributes used to construct strata?", "id": "77", "answers": [{"text": "the classes determined from the map and geographic subregions within the ROI", "answer_start": 335}]}, {"is_impossible": true, "question": "What is stratified random sampling?", "id": "78", "answers": []}, {"is_impossible": true, "question": "How many strata should I construct?", "id": "79", "answers": []}], "context": "There is often a desire to partition the ROI into discrete, mutually exclusive subsets or strata (e.g., a global map could be stratified geographically by continents). Stratification is a partitioning of the ROI in which each assessment unit is assigned to a single stratum. The two most common attributes used to construct strata are the classes determined from the map and geographic subregions within the ROI. Stratification is implemented for two primary purposes. The first purpose is when the strata are of interest for reporting results (e.g., accuracy and area are reported by land-cover class or by geographic subregion). The second use of stratification is to improve the precision of the accuracy and area estimates. For example, when strata are created for the objective of reporting accuracy by strata, the stratified design allows specifying a sample size for each stratum to ensure that a precise estimate is obtained for each stratum. Land change often occupies a small proportion of the landscape, so a change stratum can be identified and the sample size allocated to this stratum can be large enough to produce a small standard error for the change user's accuracy estimate. "}]}, {"title": "Impact of Saharan Dust", "paragraphs": [{"qas": [{"is_impossible": false, "question": "what is Saharan Air Layer?", "id": "80", "answers": [{"text": "intense heating over the Sahara desert forms a deep mixed atmospheric layer containing hot, dry air and mineral dust. As the air mass propagates westward over the Atlantic, it is undercut by cool, moist marine air. This elevated air mass is often referred to as the Saharan Air Layer (SAL).", "answer_start": 30}]}, {"is_impossible": false, "question": "What causes the formation of Saharan Air Layer?", "id": "81", "answers": [{"text": "intense heating over the Sahara desert forms a deep mixed atmospheric layer containing hot, dry air and mineral dust.", "answer_start": 30}]}, {"is_impossible": false, "question": "How does Saharan Air Layer impact Atlantic Tropical Cyclone activity?", "id": "82", "answers": [{"text": "The SAL tends to suppress Atlantic tropical cyclone activity by introducing dry, stable air into the storm, increasing the vertical wind shear and the temperature inversion at lower level.", "answer_start": 683}]}, {"is_impossible": true, "question": "How does Sea Surface Temperature impact Atlantic Tropical Cyclone Activity?", "id": "83", "answers": []}, {"is_impossible": true, "question": "How does dust impact Atlantic Tropical Cyclone activity?", "id": "84", "answers": []}], "context": "During summer and early fall, intense heating over the Sahara desert forms a deep mixed atmospheric layer containing hot, dry air and mineral dust. As the air mass propagates westward over the Atlantic, it is undercut by cool, moist marine air. This elevated air mass is often referred to as the Saharan Air Layer (SAL). The SAL advances westward in association with the African Easterly Waves (AEWs), and it has frequently been observed to interact with tropical cyclones (TCs) within its vicinity [Dunion and Velden, 2004]. Hurricane Cindy (1999), Floyd (1999), Debby (2000), Joyce (2000), Felix (2001) and Erin (2001) are such examples. Dunion and Velden [2004] hypothesized that the SAL tends to suppress Atlantic tropical cyclone activity by introducing dry, stable air into the storm, increasing the vertical wind shear and the temperature inversion at lower level. However, the additional role of dust in the SAL acting as cloud-nucleating aerosol on the storm development has yet to be determined. "}]}, {"title": "Airborne Dust, Tropical Cyclone, Atlantic", "paragraphs": [{"qas": [{"is_impossible": false, "question": "How much dust is transported across the Atlantic every year?", "id": "85", "answers": [{"text": "It is estimated that 240 \u00b1 80 million tons of Saharan dust are transported from Africa to the Atlantic Ocean every year [Kaufman et al., 2005].", "answer_start": 0}]}, {"is_impossible": false, "question": "How does dust impact earth's radiation budget?", "id": "86", "answers": [{"text": "Dust can directly impact the radiative balance of the earth by absorbing and scattering sunlight.", "answer_start": 144}]}, {"is_impossible": false, "question": "How does does impact cloud formation?", "id": "87", "answers": [{"text": "Dust, especially those coated with sulfur and other soluble materials [Levin et al., 1996], can also affect the cloud development by acting as cloud condensation nuclei (CCN), giant CCN (GCCN) and ice nuclei (IN) [DeMott et al., 2003; van den Heever et al., 2006]", "answer_start": 242}]}, {"is_impossible": true, "question": "How does Sea Surface Temperature impact Atlantic Tropical Cyclone Activity?", "id": "88", "answers": []}, {"is_impossible": true, "question": "Do mesoscale convective systems form because of airborne dust?", "id": "89", "answers": [], "plausible_answers": [{"text": "Analysis of visible satellite imagery over the east Atlantic shows that the dust in the SAL can be drawn into nearby mesoscale convective systems, which can later develop into TCs. Hurricane Erin (2001) was one example", "answer_start": 507}]}], "context": "It is estimated that 240 \u00b1 80 million tons of Saharan dust are transported from Africa to the Atlantic Ocean every year [Kaufman et al., 2005]. Dust can directly impact the radiative balance of the earth by absorbing and scattering sunlight. Dust, especially those coated with sulfur and other soluble materials [Levin et al., 1996], can also affect the cloud development by acting as cloud condensation nuclei (CCN), giant CCN (GCCN) and ice nuclei (IN) [DeMott et al., 2003; van den Heever et al., 2006]. Analysis of visible satellite imagery over the east Atlantic shows that the dust in the SAL can be drawn into nearby mesoscale convective systems, which can later develop into TCs. Hurricane Erin (2001) was one example. Although previous studies have shown that large numbers of dust particles can impact the development of shallow convective clouds, the role of CCN on the development of highly organized, strong convective systems such as TCs has not been thoroughly investigated. This study will examine the impact of dust acting as CCN on the initiation and evolution of a TC using numerical simulations."}]}, {"title": "Airborne Dust, Tropical Cyclones", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What role does dust play in the development of tropical cyclones?", "id": "90", "answers": [{"text": "dust as CCN may play a role in a TC's development during its interaction with the SAL", "answer_start": 42}]}, {"is_impossible": false, "question": "What numerical model can you use to simulate tropical cyclones?", "id": "91", "answers": [{"text": "RAMS model initialized with a pre-TC MCV", "answer_start": 174}]}, {"is_impossible": false, "question": "What role do environmental conditions play on determining the impact of CCN on storm intensity?", "id": "92", "answers": [{"text": "It has also been shown that the impact of varying CCN on storm intensity evolution is modified by other environmental conditions, such as the ambient GCCN concentration and its vertical profile.", "answer_start": 502}]}, {"is_impossible": true, "question": "What roles does atmospheric dynamics play in the intensification of tropical cyclones?", "id": "93", "answers": []}, {"is_impossible": true, "question": "Do a wide range of meteorological conditions impact tropical cyclone development?", "id": "94", "answers": [], "plausible_answers": [{"text": "he relative importance of nucleating aerosols under various meteorological conditions, such as SST, wind shear and dry air intrusion, needs to be evaluated. Such impacts will need to be examined in a comprehensive coupled surface-ocean atmosphere model under a wide range of conditions in the future.", "answer_start": 1127}]}], "context": "This paper presents evidence to show that dust as CCN may play a role in a TC's development during its interaction with the SAL. The simulations of an idealized TC using the RAMS model initialized with a pre-TC MCV have shown that dust in the SAL acting as CCN can influence TC development by inducing changes in the hydrometeor properties, modifying the storm diabatic heat ing distribution and thermodynamic structure, and ultimately influencing the TC intensity through complex dynamical responses. It has also been shown that the impact of varying CCN on storm intensity evolution is modified by other environmental conditions, such as the ambient GCCN concentration and its vertical profile. Ensemble simulations with combinations of various CCN, GCCN, and IN profiles under a variety of environmental conditions will be necessary in the future. [15] In nature, relationships between CCN, GCCN and IN in SAL-TC systems are more complex than suggested by the idealized simulations presented here. Sea salt and other particles from evaporated sea spray generated by high winds are also significant sources of CCN and GCCN. The relative importance of nucleating aerosols under various meteorological conditions, such as SST, wind shear and dry air intrusion, needs to be evaluated. Such impacts will need to be examined in a comprehensive coupled surface-ocean atmosphere model under a wide range of conditions in the future. "}]}, {"title": "climate change", "paragraphs": [{"qas": [{"is_impossible": false, "question": "The geographic distribution of adaptation action challenges what?", "id": "95", "answers": [{"text": "The traditional north-south dichotomy", "answer_start": 60}]}, {"is_impossible": false, "question": "The adaptation deficit appears to be significant to who?", "id": "96", "answers": [{"text": "Middle-income nations", "answer_start": 423}]}, {"is_impossible": false, "question": "middle-income nations who often have similar vulnerability profiles to who?", "id": "97", "answers": [{"text": "Low income countries", "answer_start": 151}]}, {"is_impossible": true, "question": "How long does it take the adaptation deficit to improve? ", "id": "98", "answers": []}, {"is_impossible": true, "question": "What improves the adaptation deficit?", "id": "99", "answers": [], "plausible_answers": [{"text": "Reporting", "answer_start": 207}]}], "context": "The geographic distribution of adaptation action challenges the traditional north-south dichotomy which often captures climate change discourse. While low income countries are underrepresented in adaptation reporting, there are interesting anomalies including more reporting from Africa than North America, and considerable variation among nations within global regions. The adaptation deficit appears to be significant in middle-income nations who often have similar vulnerability profiles to low income countries but do not have access to adaptation funds through the FCCC. Nevertheless, differences in the types of adaptations between north and south are indicative of unequal adaptive capacity. Thus high income countries are more likely to be investing in proactive adaptations coordinated at a government level, which are expected to be more effective than the reactive responses common in low income nations "}]}, {"title": "Climate change", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Changing temperature and precipitation pattern will produce a strong direct impact on what?", "id": "100", "answers": [{"text": "Natural and modified forests", "answer_start": 109}]}, {"is_impossible": false, "question": "The equilibrium models and some dynamic vegetation models project that this vegetation shift toward newly available areas with favorable climate conditions will eventually result in?", "id": "101", "answers": [{"text": "Forest expansion and replacement of up to 50% ", "answer_start": 476}]}, {"is_impossible": false, "question": "What facilitates Timber production?", "id": "102", "answers": [{"text": "Human action", "answer_start": 1143}]}, {"is_impossible": true, "question": "How do human actions affect both natural and modified forests?", "id": "103", "answers": []}, {"is_impossible": true, "question": "Which industry may lead to massive loss of natural forests with increased deforestation?", "id": "104", "answers": []}], "context": "It is likely that changing temperature and precipitation pattern will produce a strong direct impact on both natural and modified forests. A number of biogeographical models demonstrate a polarward shift of potential vegetation for the 2\u00d7CO2 climate by 500 km or more for boreal zones (11-13). The equilibrium models and some dynamic vegetation models project that this vegetation shift toward newly available areas with favorable climate conditions will eventually result in forest expansion and replacement of up to 50% of current tundra area. There is, however, a concern that the lagged forest migration (compare the tree species migration rates after the last glacial period of few kilometers per decade or less to projected future climate zones shift rate of 50 km per decade) may lead to massive loss of natural forests with increased deforestation at the southern boundary of the boreal forests and a correspondent large carbon pulse (13-15). At the same time, some researchers maintain that tree species migration rates can be much more rapid (16). For timber production, which relies on managed forests with migration facilitated by human actions, this negative effect of lagged migration might be of lesser importance than for natural forests."}]}, {"title": "Climate change", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Many major cities are on low lying areas and/or close to, coasts are more vulnerable to what?", "id": "105", "answers": [{"text": "sea level rise/storm surge", "answer_start": 125}]}, {"is_impossible": false, "question": "Coastal city towns contain what?", "id": "106", "answers": [{"text": "Large human populations.", "answer_start": 184}]}, {"is_impossible": false, "question": "t larger urban settlements tend to be more concentrated in?", "id": "107", "answers": [{"text": "Low elevation coastal zones", "answer_start": 392}]}, {"is_impossible": true, "question": "Is the risk factor the same for cities located near rivers?", "id": "108", "answers": []}, {"is_impossible": true, "question": "Which densely inhabited coastal areas and large cities are already below normal high-tide levels, and prone to flooding from storm surges?", "id": "109", "answers": [], "plausible_answers": [{"text": "Asian cities", "answer_start": 690}]}], "context": "Many major cities are on low lying areas and/or close to, coasts (Nicholls, 2004), and so are potentially more vulnerable to sea level rise/storm surge. Indeed, coastal cities contain large human populations and are the centre of nationally important socio-economic activities (see Nordhaus, 2006). McGranahan et al (2006) report that larger urban settlements tend to be more concentrated in low elevation coastal zones, and that around 65% of cities with populations greater than 5 million are located in these zones. In all global regions, there are densely inhabited coastal areas and large cities that are already below normal high-tide levels, and prone to flooding from storm surges. Asian cities are found to be particularly low-lying. The most threatened coastal urban environments comprise of deltas, low-lying coastal plains, islands and barrier islands, beaches, and estuaries. Direct impacts from sea level rise include inundation and displacement, coastal erosion and land loss, increased storm flooding and damage, increased salinity in estuaries and coastal aquifers, and rising coastal water tables and impeded drainage. Potential indirect impacts include changes in the distribution of bottom sediments, changes in the functions of coastal ecosystems and impacts on recreational activities. "}]}, {"title": "Water quality", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What are two important sources of water for drinking in many parts of the world?", "id": "110", "answers": [{"text": "river water and spring water", "answer_start": 55}]}, {"is_impossible": false, "question": "What does the Mann-Kendall test do?", "id": "111", "answers": [{"text": "Delineate the variations of spring water quality and quantity under climate change and human activities.", "answer_start": 502}]}, {"is_impossible": false, "question": "What was the cause of spring discharge attenuation?", "id": "112", "answers": [{"text": "Decreasing precipitation ", "answer_start": 672}]}, {"is_impossible": true, "question": "What is the major effects from excessive mining on karst springs?", "id": "113", "answers": []}, {"is_impossible": true, "question": "Which anthropogenic activity causes pollution in karst springs?", "id": "114", "answers": [], "plausible_answers": [{"text": "Coal mining", "answer_start": 786}]}], "context": "Apart from groundwater mentioned in the above studies, river water and spring water are also important sources of water for drinking in many parts of the world. In this issue, one paper (He et al. 2019) focus on karst spring water for drinking purpose, and another paper (Ahmed et al. 2019) focus on river water quality. In the study by He et al. (2019), the authors analyzed the time series of karst spring water quality and quantity of two karst springs in China using the Mann-Kendall trend test to delineate the variations of spring water quality and quantity under climate change and human activities. They proved in their study that climate change, particularly the decreasing precipitation was responsible for spring discharge attenuation, while anthropogenic activities such as coal mining and quarrying, agriculture and urbanization were responsible for spring water quality deterioration."}]}, {"title": "Environmental Degradation", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What is the sources for 25 billion pounds of toxic pollutants added to the environment?", "id": "115", "answers": [{"text": "US factories and mines", "answer_start": 81}]}, {"is_impossible": false, "question": "How much pesticide is sprayed per year on crops?", "id": "116", "answers": [{"text": " 2.2 billion pounds", "answer_start": 142}]}, {"is_impossible": false, "question": "Have vast majority of artificial chemicals been screened for toxicity?", "id": "117", "answers": [{"text": "No", "answer_start": 742}]}, {"is_impossible": true, "question": "How many synthetic organic chemicals are being distributed for public use?", "id": "118", "answers": []}, {"is_impossible": true, "question": "Which mitigation steps can be conducted to avoid dangerous artificial chemicals to be emitted? ", "id": "119", "answers": []}], "context": "Every year 25 billion pounds of toxic pollutants are added to the environment by US factories and mines (Fagin & Lavelle, 1999). Additionally, 2.2 billion pounds per year of pesticides (eight pounds per citizen) are sprayed on our crops (Natural Resources Defense Council Staff, 1995). Certain pesticides that are illegal in the United States are used in other countries on food which is then imported back into the US, exposing Americans to the same health risks faced by individuals in those other countries (Satcher, 2000). Annual world production of synthetic organic chemicals has grown exponentially since the early 20 century. The vast majority of artificial chemicals have never been screened for toxicity. Chemical manufacturers are not required to prove safety; instead the legal burden is on the government to prove that a product is dangerous, and testing is only done after a substance has been impugned."}]}, {"title": "Pollution", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What percentage of leaching agents are commonly injected into an ore body at a volume ratio of 1:3?", "id": "120", "answers": [{"text": "0.5% - 2%", "answer_start": 12}]}, {"is_impossible": false, "question": "During actual mining process, why is the dosage of (NH4)2SO4 solution increased?", "id": "121", "answers": [{"text": "REE extraction efficiency", "answer_start": 364}]}, {"is_impossible": false, "question": "what results when the dosage of (NH4)2SO4 solution is increased?", "id": "122", "answers": [{"text": "In an excessive amount of ammonium ions persisting in the soil.", "answer_start": 401}]}, {"is_impossible": true, "question": "How does the chemical make-up in water change due to the presence of leaching agents?", "id": "123", "answers": []}, {"is_impossible": true, "question": "Why are large amounts of leaching agent being injected into soils?", "id": "124", "answers": [], "plausible_answers": [{"text": "Due to a lack of knowledge", "answer_start": 201}]}], "context": "Currently, 0.5% - 2% of (NH4)2SO4 leaching agents are commonly injected into an ore body at a volume ratio of 1:3 (leaching agent: ore soil) (Tang et al., 2018). However, in the actual mining process, due to a lack of knowledge regarding the leaching mechanism, the concentration and dosage of (NH4)2SO4 solution have been unintentionally increased to improve the REE extraction efficiency, resulting in an excessive amount of ammonium ions persisting in the soil (Yang et al., 2013). This not only changes the soil properties but also leads to the diffusion of (NH4)2SO4 into the adjacent soil and water system via rainwater or runoff, resulting in an unparalleled risk to the environment."}]}, {"title": "Cold-Air Damming", "paragraphs": [{"qas": [{"is_impossible": false, "question": "Where is the surface low pressure system centered in Fig. 8a?", "id": "125", "answers": [{"text": "175 km east of Jackson, Mississippi", "answer_start": 200}]}, {"is_impossible": false, "question": "At what time and date was the anticyclone stationary? ", "id": "126", "answers": [{"text": "At 0000 UTC 22 March.", "answer_start": 0}]}, {"is_impossible": false, "question": "How was the increase in troughing and ridging determined?", "id": "127", "answers": [{"text": "In the altimeter setting analysis.", "answer_start": 715}]}, {"is_impossible": true, "question": "What were the conditions in the TN Valley at 0000 UTC due to the ridging?", "id": "128", "answers": []}, {"is_impossible": true, "question": "Did the surface wind speeds increase with the increase surface pressure gradient?", "id": "129", "answers": []}], "context": "At 0000 UTC 22 March the surface anticyclone in Fig. 6b has remained relatively stationary, while the surface low pressure system associated with the southern 500 mb trough in Fig. 8a is now centered 175 km east of Jackson, Mississippi (JAN). The relative movements of the surface cyclone and anticyclone have further increased the surface cyclone and anticyclone have further increased the surface pressure gradient in the mountain-parallel direction to the east of the Appalachians (Fig. 6b). Moreover, an increase in both the ridging to the east of the mountain crests from Virginia to Georgia, and in the troughing over and to the west of the Appalachians from New York to Tennessee is becoming clearly evident in the altimeter setting analysis."}]}, {"title": "Drylines", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What is the significance of drylines?", "id": "130", "answers": [{"text": "they tend to act as a trigger for thunderstorms", "answer_start": 165}]}, {"is_impossible": false, "question": "When are drylines most frequent?", "id": "131", "answers": [{"text": "during the early summer", "answer_start": 421}]}, {"is_impossible": false, "question": "How do drylines respond differently during El Ni\u00f1o and La Ni\u00f1a years?", "id": "132", "answers": [{"text": "generally more drylines during El Ni\u00f1o over eastern South Africa and fewer during La Ni\u00f1a", "answer_start": 645}]}, {"is_impossible": true, "question": "How are drylines different from warm or cold fronts", "id": "133", "answers": []}, {"is_impossible": true, "question": "Why do drylines trigger thunderstorms?", "id": "134", "answers": []}], "context": "\"Drylines\" are used to describe boundaries separating regions of very dry air from those with much higher moisture content. The importance of these drylines is that they tend to act as a trigger for thunderstorms, which can produce severe weather. In this study, we build a long-term climatological description of drylines in subtropical southern Africa. We find that drylines are most frequent over eastern South Africa during the early summer, a time when storms with large hail and damaging winds are most likely to occur. Drylines are sensitive to moisture circulation patterns and respond differently during El Ni\u00f1o and La Ni\u00f1a years, with generally more drylines during El Ni\u00f1o over eastern South Africa and fewer during La Ni\u00f1a."}]}, {"title": "Pollution", "paragraphs": [{"qas": [{"is_impossible": false, "question": "AN pollution in mine soil is becoming a serious problem due to?", "id": "135", "answers": [{"text": "The use of high concentrations of (NH4)2SO4", "answer_start": 81}]}, {"is_impossible": false, "question": "What did scientists use to prevent and control AN pollution?", "id": "136", "answers": [{"text": "MgSO4", "answer_start": 342}]}, {"is_impossible": false, "question": "What did scientists use as a washing agent instead of water?", "id": "137", "answers": [{"text": "KCl solution", "answer_start": 682}]}, {"is_impossible": true, "question": "How does the KCI solution dilutes the AN pollution compared to water?", "id": "138", "answers": []}, {"is_impossible": true, "question": "What chemical can prevent and control AN pollution?", "id": "139", "answers": [], "plausible_answers": [{"text": "(NH4)2SO4", "answer_start": 115}]}], "context": "The problem of AN pollution in mine soil is becoming increasingly serious due to the use of high concentrations of (NH4)2SO4 (Wen, 2017). To prevent and control AN pollution, Qiu et al, (2008) studied the transport kinetics of pollutants and optimized the leaching process to reduce the consumption of (NH4)2SO4 (Xiao et al 2015) showed that MgSO4, a new type of leaching agent without ammonia, can be used instead of (NH4)2SO4 to extract REEs without AN pollution. Yang et al. (2016) explored the spatial distributions of AN in the soil residues of an REE mining area and still found high concentrations of AN in the surface tailing soil after the mining process. They then used a KCl solution as a washing agent instead of water to solve the AN pollution problem quickly and effectively. However, only a few studies have reported on AN variation, its impact factors, and its distribution characteristics in deep soil profiles in WCED-REOs."}]}, {"title": "GIS", "paragraphs": [{"qas": [{"is_impossible": false, "question": "What is a centralized source that is found in the center of the landscape and the center of North Alabama citizens' lives?", "id": "140", "answers": [{"text": "The Tennessee River", "answer_start": 10}]}, {"is_impossible": false, "question": "The river remains as the direct resource that sustains what?", "id": "141", "answers": [{"text": "North Alabama's agricultural spaces", "answer_start": 469}]}, {"is_impossible": false, "question": "How much surface water utilized for farming is expected to rise by 2040?", "id": "142", "answers": [{"text": "40 percent", "answer_start": 698}]}, {"is_impossible": true, "question": "How much land was utilized for farming from past generations?", "id": "143", "answers": []}, {"is_impossible": true, "question": "Who has utilized the land?", "id": "144", "answers": [], "plausible_answers": [{"text": "Humans", "answer_start": 313}]}], "context": "Visually, the Tennessee River is a centralized source found at the center of the landscape and the center of North Alabama citizens' lives. \"The Tennessee River is central to the lives of north Alabamians\" (Anonymous female, 2021, qualitative study findings). Surrounding the river is a fertile river valley that humans have utilized for cotton, soybeans, poultry, and livestock farming. Combined with the fertile soil, the river remains the direct resource to sustain North Alabama's agricultural spaces. In 2015, surface water supplied 50 mgd, or 79.4 percent of the total withdrawal for irrigation use in North Alabama (Tennessee Valley Authority, 2018). This percentage is predicted to rise by 40 percent by 2040. Then, the percentage of surface water is accessed to maintain the number of farms (11,231) in North Alabama. Further statistical indication of farming's influence on citizens' identity is represented by 33,049,300 acres of land utilized for farming out of a total land cover of 9,793,100 in 2016 and generations before (Farmland Information Center, 2022)."}]}]}