Oblique lumbar interbody fusion (OLIF) can be combined with different screw instrumentations. The standard screw instrumentation is bilateral pedicle screw fixation (BPSF). However, the operation is time consuming because a lateral recumbent position must be adopted for OLIF during surgery before a prone position is adopted for BPSF. This study aimed to employ a finite element analysis to investigate the biomechanical effects of OLIF combined with BPSF, unilateral pedicle screw fixation (UPSF), or lateral pedicle screw fixation (LPSF). In this study, three lumbar vertebra finite element models for OLIF surgery with three different fixation methods were developed. The finite element models were assigned six loading conditions , and the total deformation and von Mises stress distribution of the finite element models were observed. The study results showed unremarkable differences in total deformation among different groups (the maximum difference range is approximately 0.6248% to 1.3227%), and that flexion has larger total deformation (5.3604 mm to 5.4011 mm). The groups exhibited different endplate stress because of different movements, but these differences were not large (the maximum difference range between each group is approximately 0.455% to 5.0102%). Using UPSF fixation may lead to higher cage stress (411.08 MPa); however, the stress produced on the endplate was comparable to that in the other two groups. Therefore, the length of surgery can be shortened when unilateral back screws are used for UPSF. In addition, the total deformation and endplate stress of UPSF did not differ much from that of BPSF. Hence, combining OLIF with UPSF can save time and enhance stability, which is comparable to a standard BPSF surgery; thus, this method can be considered by spine surgeons. Lumbar interbody fusion, including anterior lumbar interbody fusion (ALIF), posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), lateral lumbar interbody fusion (LLIF), and oblique lumbar interbody fusion (OLIF), is widely used for the treatment of vertebral pseudarthrosis, spinal stenosis or foraminal stenosis, spondylolisthesis, and lateral listhesis ,2,3,4. OHowever, the standard procedure of OLIF includes implantation of the cage through a retroperitoneal approach in the lateral position and subsequent implantation of pedicle screws through the posterior approach in the prone position. The disadvantages of this procedure include the extra operation room (OR) time and manpower required for reposition, and increased cost of anesthesia, sterile draping, and tools . To overMills et al. performed LLIF combined with posterior pedicle screw insertion in the single-lateral position . This apSome studies compared TLIF with either bilateral or unilateral pedicle screw fixation (UPSF). Compared with TLIF with bilateral screw fixation, TLIF with unilateral screw fixation achieved similar clinical outcomes ,13 and fFinite element analyses are commonly used in orthopedic biomechanics analyses. Previous studies have employed a finite element analysis to examine the biomechanics of different OLIF fixation methods. Du et al. examined the effects of different degenerative disc diseases , using finite element analysis to observe vertebral ROM, intradiscal pressure, facet joint force, stress in the annulus fibrosus and endplate, and other study observation markers . Zhang eThe aforementioned studies show that different surgical methods for lumbar OLIF exist. Currently, several special cases in clinical practice require UPSF or LPSF. However, existing studies have not comprehensively examined the effects of endplate stress in different segments, and the mechanical results required by spine surgeons could not be obtained. Therefore, the primary objective of this study was to employ finite element analysis to evaluate the biomechanical effects of three pedicle screw fixation methods . Concurrently, this study examined the difference in stress in different bone segments under different fixation methods. Thus, this study hypothesized that the stress in bone segments is different between PRSF, UPSF, or LPSF.To evaluate the effects of three different lumbar vertebral OLIF surgical fixation methods, this study used the computed tomography (CT) images of an artificial lumbar vertebrae model for finite element analysis of the computer lumbar vertebrae model. A commercially available artificial lumbar vertebrae model  was used to obtain CT images using CT scanning and the medical image reconstruction software Mimics . Grayscale values were used to select bones in the vertebral model in CT images, and a computer lumbar vertebrae model was constructed.Mimics was used to construct a lumbar vertebrae model. Subsequently, Geomagic Design X  was used to convert the computer lumbar vertebrae model to an igs file. Then, this igs file was imported into the three-dimensional computer-assisted design software  and was drawn and segmented . In thisFor the pedicle screw, three computer models with different pedicle screw systems implanted in the lumbar vertebrae were constructed. The pedicle screw system mainly comprised the pedicle screw (5.5 mm in diameter and 45 mm in length), screw tulip, and rod. In addition, the cage was constructed and inserted between the L3 and L4 intervertebral discs in the lumbar vertebrae model, which was used to simulate vertebral arch implantation and fixation. This study mainly examined three pedicle screw fixation methods in the lumbar vertebrae L3 and L4. The three fixation method groups were as follows: Group 1 (BPSF): BPSF, in which traditional pedicle screws were implanted in the posterior side of L3 and L4; Group 2 (UPSF): the unilateral pedicle screw fixation, in which unilateral pedicle screws were implanted in the posterior side of L3 and L4; and Group 3 (LPSF): the lateral pedicle screw fixation, in which traditional pedicle screws were implanted in the left anterior side of L3 and L4 .The three computer models were then imported into the finite element analysis software ANSYS Workbench  for finite element analysis.X-, Y-, and Z-axis displacements were used) for the fixed sacral model  when an OLIF cage was used in lumbar interbody fusion. A finite element analysis was used for the simulation of the vertebral model under three different fixation methods, and to evaluate the total deformation and stress distribution of the different methods. In the procedural workflow of finite element analysis employed in this study, the primary steps included the initial creation of a computer model of the spine. Subsequently, the computer model underwent mesh generation to facilitate segmentation, followed by the specification of material properties to mimic spinal characteristics. Computational numerical analysis techniques were then utilized to solve the model. Finally, a comprehensive biomechanical evaluation of parameters of interest was conducted. Because the structure of the spine is quite complex, finite element analysis was a suitable method for our research to evaluate it thoroughly.Observation of total deformation of the vertebrae under BPSF, UPSF, or LPSF showed that the stress experienced by the three different fixation methods was different during six movements , which is primarily because the differences between the movements were larger, resulting in different deformations. Furthermore, total deformation was observed to be larger under flexion and lower under extension, which is primarily because the extension is affected by restriction in the posterior vertebra (facet joint) and therefore has lower displacement deformation. In addition, the differences among the groups were not large under the same movement, which is primarily because the implantation region in this study was L3–4; therefore, the total deformation difference was not large. According to Hooke’s law, stress = Young’s modulus×strain, and deformation is associated with strain. Therefore, under the same movement, as Young’s modulus of the endplate used in different groups is the same, the maximum difference in the stress between the upper endplate of L1 and lower endplate of L5 was not large.We observed the stress of the endplate near L3–4 under identical movements, and found that the maximum stress difference between the lower endplate of L3 and upper endplate of L4 was not large, which is primarily because the difference in deformation among the groups was not large under BPSF, UPSF, or LPSF; therefore, the stress difference in endplates near L3–4 was low. Similarly, we observed the maximum stress of endplates near the segments, and found that the maximum stress difference between the lower endplate of L2 and upper endplate of L5 was low. Furthermore, observation of the stress on the implanted cage showed that under the same movements, the UPSF implantation method resulted in greater stress on the cage, which is primarily because two pedicle screws were used for fixation in BPSF, and this produces external protective effects on the case, thereby decreasing cage deformation and resulting in low cage stress. The trend in this study’s results is consistent with other previous studies ,18. MoreObservation of stress on the screw showed that the stress was lower when LPSF was used for the same movements. Using BPSF or UPSF causes greater stress on the screw; however, these differences are not large. The reason for the lower stress under LPSF is that the screw is parallel to the cage. This causes the deformation on the screw to be insignificant, thereby decreasing strain and resulting in lower stress. Furthermore, the stress on the screw is different because the location of lateral pedicle screw fixation when LPSF is used is different from that under BPSF and UPSF. In addition, the stress on the screws under the three different fixation methods was much lower than the yield strength.OLIF with lateral modular plate fixation is an alternative method to provide similar axial and lateral stability, but a larger flexion–extension ROM . This apThis study has some limitations. As the lumbar vertebrae model used in this study has a more complex structure, common settings were used for orthopedic materials in finite element analysis. The materials used in this study were set as homogeneous, isotropic, and linearly elastic materials ,29. SuchThis study employed finite element analysis to evaluate the effects of three different pedicle screw implantation methods in OLIF surgery and examined the correlation between OLIF and BPSF, UPSF, and LPSF. However, some potential directions for future studies, such as using unilateral pedicle screws for multi-segment fixation, and lateral pedicle screws for multi-segment fixation, remain. The biomechanics of these different fixation methods are of interest to spine surgeons. However, the vertebra model construction in this study can be used in the future for further finite element analyses and biomechanical evaluation of vertebral fixation. Beyond this finite element study, future studies such as sawbones study, cadaver studies, clinical studies, and biomechanical evaluation of other spinal implant designs are necessary for confirmation of clinical applications and outcomes.Though OLIF plus LPSF does not need an additional back wound for pedicle screw implantation and is a time-saving procedure, it could not be applied to patients with spondylolisthesis of grade II or higher due to weaker lumbar flexion–extension stability. Up to now, BPSF is still a mainstream supplementary fixation for OLIF. This study employed finite element analysis to evaluate the biomechanical effects of three different pedicle screw fixation methods  combined with lumbar vertebral OLIF surgery. The study revealed that the total deformation and endplate stress of UPSF did not differ much from BPSF. For spine surgeons, OLIF plus UPSF provides similar stability of OLIF plus BPSF, diminishes surgical wounds, and might decrease surgical time and intraoperative radiation exposure.


Octopus insularis in each stage of the production chain, comprehending capture, post-capture, processing and commercialization, in terms of the presence of total and fecal coliforms at the Veracruz Reef System, Gulf of Mexico. The environmental and anthropogenic influence on the space–temporal concentration of coliforms were analyzed in sea water, fresh octopus, fresh water, ice and octopus, both packed in ice and boiled. Most relevant results indicated that coliforms are present in the octopus production chain, being highest in the marketing stage. The coliform concentration increased during the rainy season and was highest in the reefs closer to the coast, which has a major anthropogenic influence. These results point out the urgent need to implement an efficient cold chain with adequate handling practices to try to reverse these microbiological conditions and improve the octopus quality and food safety.The contamination of coastal waters, unhealthy conditions and inadequate handling practices tend to reduce the sanitary quality of fishery products, thus impacting its marketing. With this in mind, we investigate the microbiological quality of the p = 0.0129) and among the three climatic seasons, increasing during the rainy season, highlighting La Gallega with 203.33 ± 63 MPN . The results provide evidence of the environmental and anthropogenic influences on coliform concentrations and the urgent need to implement an efficient cold chain throughout octopus production stages with adequate handling practices to reverse this situation.Coliforms are relatively common in aquatic environments, but their concentrations can be increased by environmental changes and anthropogenic activities, thus impacting fisheries resources. To determine the microbiological quality in the octopus production chain , total (TC) and fecal (FC) coliforms were quantified in sea water, fresh octopus, fresh water, ice and octopus in two presentations: packed in ice and boiled. Samples came from fishing zones Enmedio, Chopa and La Gallega at the Veracruz Reef System (VRS) during dry, rainy and windy seasons. The coliforms were determined using the most probable number technique (MPN). The most relevant results indicated that octopus packed in ice coming from the commercialization stage had FC levels >540 MPN/100 g, which exceeded the permissible limits (230 MPN/100 g). Therefore, these products present a risk for human consumption. Differences in FC were observed in octopuses between the three fishing zones (H = 8.697;  Foods of marine origin are important sources of protein of high biological value but are highly perishable if proper safety measures are not taken. The quality and safety of fishery products is essential for their commercialization ,2. The cOctopus insularis in the VRS consists of four stages before consumption: capture, post-capture, processing and commercialization [The octopus fishery in Mexico is important from an economic and social point of view, being the second most important fishery in the Gulf of Mexico and the Caribbean. ,8. The olization . Artisanlization ,12,13. Plization .Octopus maya [O. insularis production chain have not been evaluated, it being essential to know them to improve their quality and marketability.The commercialization of artisanal catches increases the risk of transferring alimentary infections due to limitations on the sanitary and handling conditions of fishery products, such as intermittent access to potable water, frequent breakdowns of freezing systems, and surface areas inadequate for processing raw materials ,6,15. Thpus maya . NeverthMicrobiological quality in fishery resources is determined by the presence and concentration of total and fecal coliforms. The habitat of both coliforms is the intestine , but theO. insularis in each stage of the production chain and provide evidence of the environmental and anthropogenic influences on the space–temporal concentration of coliforms, sustaining the urgent need to implement an efficient cold chain with adequate handling practices to revert this situation.Here, we present data on the microbiological quality of the Two representative octopus fishing zones in the VRS (19°05′–19°14′ N and 95°93′–96°15′ W) were chosen for sampling: in the northern zone, considering the proximity to the coast and the port in La Gallega reef, and in the southern zone in Enmedio and Chopa reefs, considering the influence by anthropogenic activities and discharge from rivers . The infSamples of seawater, freshwater, octopuses, and ice from each stage of the production chain in the three-sample site and the three climatic seasons were taken. Capture stage included seawater samples from the water column at 150 cm depth, in duplicate, and stored in sterile containers of 250 mL capacity. They were kept refrigerated until processing. Also, three whole octopus freshly caught were preserved in sterile whirl-pak bags, on ice until processing. In post-capture stage, 100 mL freshwater, where the octopuses are stored before being sold, was sampled, and then preserved in sterile whirl-pak bags until its analyses. For the processing stage, three samples of the boiled octopus were taken, preserved in sterile conditions, and analyzed, while for the commercialization stage, three octopuses packed in ice and 250 g of the ice in which the octopuses are placed for exhibition and sale were sampled. All samples were collected, processed, and contrasted following the norms stipulated in APHA 2012  and NOM-−1, 10−2 and 10−3). In the case of octopus, 10 g of muscle was taken and homogenized in 90 mL of saline peptonized water, from which serial dilutions were performed for presumptive and confirmatory tests, in the same way as was described for water samples.For the water samples  three serial dilutions were made by transferring 1 mL of the sample in 9 mL of saline peptonized water to obtain 3 concentrations (10Escherichia coli Broth in 44 °C (confirmation for the FC).The microbiological analysis of seawater, freshwater, ice and octopuses were carried out in accordance with the protocols described by the U.S. Food and Drug Administration , which sFrom the number of positive tubes in the presumptive and confirmatory tests, the MPN of TC and FC in 100 mL of sample was calculated, referring to the MPN statistical tables. In the case that the presumptive test did not show turbidity and gas production, the minimum value expressed in the table was reported.The MPN for TC and FC in each sample was obtained in accordance with norm NOM-112-SSA1-1994  and thenNormality and homoscedasticity tests were applied on TC and FC data to discern about the use of parametric or non-parametric tests. Results led us to choose the Kruskal–Wallis test to determine the influence of the climatic seasons and fishing zones on the MPN for TC and FC on each stages of the production chain. In the cases where significant differences were found, multiple contrast tests were applied following the Dunn test. All tests were carried out considering a significance level of α = 0.05. Analyses were performed with the STATA package version 13.1.To analyze climatic variation, we utilized the database MOHICOVER (Monitoring of Hydrography and Currents in Veracruz), which contains monthly data of temperature and salinity of the study area (VRS) during 2019. Also, we collected precipitation data and water discharge flow from the Jamapa River based on official CONAGUA statistics  from January 2019 to December 2020.The spatial and temporal analysis of the TC and FC show that the seawater did not detect statistically significant differences in TC concentrations between the three climatic seasons in the reefs evaluated . The higp < 0.05), Chopa  and La Gallega . In contrast, there were no significant differences in the MPN for TC among the reefs   .p < 0.05) were observed in the MPN for TC isolated in fresh water in the different climatic seasons, with higher values in the dry season, while for the processing stage, no statistically significant differences  were observed between the MPN for TC of the boiled vs. fresh octopuses . For the samples of ice, the same high MPN value for TC was found during the three climatic seasons  in the reefs evaluated (p < 0.05) and within reefs sampled: Enmedio , Chopa  and La Gallega   .p < 0.05), with a marked increase in this value for the fresh water in the rainy season, while for the processing stage, no statistically significant differences between the MPN for FC in the boiled vs. fresh octopuses   . p < 0.05). Moreover, the ice used to preserve the octopuses presented FC values (>800 MPN/100 g) above allowable levels (230 MPN/100 g) in all three climatic seasons  and minimum (21.8 °C) values for this variable were obtained in August and March, respectively. In relation to salinity, variations from average values were observed throughout the year. The lowest value was registered in April 2019 (30.8 UPS), the highest in October 2019 (35.5 UPS). Precipitation in 2020 was higher than in 2019, with above-average increases in October 2019 and September 2020, and periods of low precipitation between December and April in both years. A similar tendency was found for the rate of discharge from the Jamapa River, where we found an increase from June/July to October in both 2019 and 2020 .The analysis of coliform concentrations in the different stages of the octopus production chain in the VRS revealed an increased tendency in the MPN for both total (TC) and fecal (FC) coliforms in the octopuses from capture to the commercialization stage. In most of the cases, both values exceeded the allowable levels stipulated in the norm NOM-242-SSA1-2009 [The highest MPN of FC values in all samples of fresh octopus captured from La Gallega, during the rainy season, could be due to the greater anthropogenic impact, such as direct discharges of untreated wastewater , intenseA previous study had warned that La Gallega reef is one of the most susceptible to suffering a high degree of degradation of its waters, which can cause diseases in fish and coral . The resIn the post-capture stage, the MPN values for TC and FC in the fresh water that fishers use to preserve their catches prior to commercialization were also found to exceed the allowable limits for potable water (0 MPN for TC) ; also, tEscherichia coli and, thus, the MPN could pertain to this species or some other in the group of thermotolerant bacteria, the presence of fecal coliforms is an indicator of anthropogenic contamination that must be addressed.The handling practices of the octopus resource in both zones of the VRS do not comply with the norms NOM-242-SSA1-2009 , OIRSA  and SAGADespite having a good cooking process, there is “cross contamination” due to the lack of instruments and materials used exclusively for handling cooked products, sharing scales, trays, knives, boards and ice with other uncooked seafood products. In the same way, the high CF values in the ice during all the months sampled indicate that they do not come from potable water; in addition, the ice was used only in the commercialization stage, in non-inclined trays, which means that as the ice melts, water ice forms and is not at the temperature determined for the maintenance of the resources and the inhibition of bacterial growth. It is necessary to use and continually replace ice throughout the octopus production chain to reduce the growth of fecal coliforms.In addition to anthropogenic factors, which influence the number of total and fecal coliforms, the VRS presents a stratification of the water column that differs between seasons  . TemperaThe results of this study provide clear evidence that in order to correct this situation, the following issues must be addressed: treating all residual waters before discharging them into the sea; maintaining the cold chain throughout all stages of the octopus production chain; improving fishery infrastructure and the access to potable water; implementation of good handling and monitoring practices; and providing technical orientation and support to all the personnel involved in the octopus production chain. These measures should be complemented by the practices in Shawyer and Medina , DOF 2626 and noTotal and fecal coliforms are present in the octopus production chain from the VRS, being highest in the marketing stage, with FC values above the permissible values even in cooked octopus. The most affected octopuses were those captured in coastal waters near reefs with the greatest anthropogenic pressure. During the rainy season, the concentration of FC increases. It is necessary to strengthen the cool chain and implement good handling practices throughout the octopus production chain to improve the quality and food safety of this product.


The Galileo mission to Jupiter revealed that Europa is an ocean world. The Galileo magnetometer experiment in particular provided strong evidence for a salty subsurface ocean beneath the ice shell, likely in contact with the rocky core. Within the ice shell and ocean, a number of tectonic and geodynamic processes may operate today or have operated at some point in the past, including solid ice convection, diapirism, subsumption, and interstitial lake formation.The science objectives of the Europa Clipper mission include the characterization of Europa’s interior; confirmation of the presence of a subsurface ocean; identification of constraints on the depth to this ocean, and on its salinity and thickness; and determination of processes of material exchange between the surface, ice shell, and ocean.Three broad categories of investigation are planned to interrogate different aspects of the subsurface structure and properties of the ice shell and ocean: magnetic induction, subsurface radar sounding, and tidal deformation. These investigations are supplemented by several auxiliary measurements. Alone, each of these investigations will reveal unique information. Together, the synergy between these investigations will expose the secrets of the Europan interior in unprecedented detail, an essential step in evaluating the habitability of this ocean world. The Laplace resonance was known, along with general ideas of Europa’s size, mass, and surface reflectivity  of 0.346 ± 0.005 . Magnetic induction results break the degeneracy regarding the existence of the ocean. As described in the review by Khurana et al. , during One of the Europa Clipper’s Level-1 science requirements directly concern the interior of Europa. This requirement can be mapped to four broad science themes: characterization of the interior; confirmation of the presence of a subsurface ocean; identification of constraints on the depth to this ocean, and on its salinity and thickness; and determination of processes of surface–ice–ocean exchange. Three broad categories of investigation  are planned to interrogate different aspects of the subsurface structure and properties of the ice shell and ocean: magnetic induction, subsurface radar sounding, and tidal deformation. Alone, each of these investigations will reveal unique information. The synergy among these investigations will expose the structure and dynamics of the Europan interior in unprecedented detail, an essential step in evaluating the habitability of this ocean world.The science requirements, themes, and planned measurements designed to address them are presented in Table Gravity measurements performed by the Galileo spacecraft  but also on how internal heat is transported through the ice shell, either by conduction or sub-solidus convection  up to 100 g/kgH2O  originally in the rock was leached during an early phase of aqueous alteration  or have a stabilizing effect (negative gradient)  instrument will constrain the thickness of the ice shell, and map the vertical subsurface structure, as well as constrain its tidal deformation. Observations of the tidal deformation of the ice shell from the gravity and radio science (G/RS) investigation will recover the combined strength and thickness of the ice shell. These three investigations are supported and supplemented by several other investigations from the entire payload that will be used to resolve ambiguities and degeneracies.In addition to the instrumentation, the investigations are enabled by Europa Clipper’s unique trajectory. Rather than placing the spacecraft in orbit about Europa, where it would be subject to an inhospitable radiation environment, it enters a highly eccentric orbit about Jupiter, and spends most of its time at a larger (and safer) distance from the planet. The Europa Clipper will execute 49 close flybys of Europa itself, with closest approach distances less than 1000 km, and sometimes within 25 km of the surface. This tour design has multiple advantages over an orbital campaign. Less propellant is needed to enter a Jupiter orbit than an orbit about Europa itself. The spacecraft is able to make several encounters much closer to the surface than could be safely done while in orbit. By spending most of its time outside the high radiation environment near Jupiter, the mission lifetime is extended substantially; the baseline tour is 4.3 years long. Finally, the investigations will be able to characterize the ambient Jovian plasma and magnetic environment far from Europa, so that the observations at Europa can be placed in the context of the larger system. The tour has been designed to provide robust geographic coverage. An example of the distribution of close flybys is shown in Fig. In this section, we summarize the key contributions of each investigation to the interior science, and in the following section we discuss how the disparate datasets are synthesized into a coherent story about Europa’s interior.A magnetic field that varies in time generates a curling electric field in accordance with Maxwell’s law of induction. In the presence of a conducting material such as a salty ocean, this curling electric field will drive electric currents that generate a secondary, induced magnetic field that opposes the variation in the external field. When the body has spherical symmetry and the oscillating external magnetic field is uniform across it, the induced magnetic field consists of a dipole oscillating in response to the driving field  will be combined with data taken during close approaches to determine the driving and induced field amplitudes for at least two frequencies with a precision of ±1.5 nT. For the expected driving field amplitudes and plausible ocean structures, this is sufficient to characterize Europa’s internal structure , which consists of three fluxgate magnetometers mounted on an 8.5-m-long boom. Over the course of the mission, ECM measurements of Jupiter’s magnetic field far from Europa , REASON must record individual echoes coherently  to meet resolution requirements. After the data are downlinked, these echoes are summed on the ground through a process known as coherent integration or “stacking”, which increases the signal to noise ratio  of incoming energy, while a cold salt–ice interface (an example of ice shell structure) will reflect less than 1.5% (−18 dB). However, as the ice is warmer  near an ice–water interface, the salt–ice interface echoes can easily appear brighter to radar than the ice–water interface due to attenuation by the overlying warm ice. To resolve this ambiguity in echo strength in the context of unknown signal attenuation, complementary data are required, especially altimetry, to determine whether interfaces are in flotation over a liquid. From REASON altimetry profiles, we can predict (for a given buoyancy contrast) the shape of the subsurface interface. This approach requires minimum ground track lengths depending on the target; for icebergs in the shallow subsurface , 10 km length scales should be sufficient; testing for the ice–ocean interface requires hemispheric-scale ground tracks. REASON is also sensitive to surface and volume scattering, which is a function of wavelength, surface roughness, and subsurface structure. For a given radar wavelength, roughness or subsurface porosity at that scale can degrade the coherence of the returning energy.REASON uses two complementary radar arrays: a low resolution 9 MHz high frequency (HF) array for sounding that is relatively insensitive to surface and volume scattering and that is intended to penetrate more reliably into Europa’s ice crust, and a 60 MHz very high frequency (VHF) dual-channel interferometric array for both sounding and altimetry with high resolution. The latter is intended to limit the impact of Jovian radio-frequency noise and plasma dispersion, but it is more sensitive to scattering losses (see as described in the REASON investigation publication in this collection). The HF and VHF echoes reflected from Europa and received by the REASON instrument are organized into 2-D slices of detected energy that are termed “radargrams”; where the X-axis represents the along-track direction and the Y-axis represents time delay relative to signal transmission. With appropriate corrections to account for different speeds of propagation inside different media, depth images can be derived  requires one of the other approaches. For the deep ice shell, where resolution requirements are low, REASON reprojects its radargrams assuming all observed echoes are reflections from cross-track surface clutter. By comparing this reprojection with global surface mosaic images that will be collected by the EIS camera system, echoes that align with surface topographic features can be discriminated , the radar returns have some ambiguity in the presence of surface topography. To mitigate this uncertainty and actually exploit the multiple returns from different locations, stereo imaging of the cross-over points is needed. This knowledge of the topography will allow Europa Clipper to perform multiple altimetry measurements simultaneously and, assuming that these are statistically independent, to increase the measurement accuracy below that of the inherent range resolution , the Gravity and Radio Science investigation will measure the static components of the long-wavelength, global potential field . Because of the rapidly varying spacecraft altitude, regional to local gravity anomalies are better constrained by line-of-sight residuals  gravity moments to determine how close Europa is to hydrostatic equilibrium. Most approaches to date have used the hydrostatic assumption to derive Europa’s MoI from the estimated CCold silicate objects like Vesta and the Moon show pronounced departures from hydrostatic equilibrium, while icy bodies like Titan or Enceladus depart slightly from this state. For the latter two bodies, correlations between the gravity and surface topography have been used to infer not only the moment of inertia, but also the degree of compensation (and hence the thickness) of the ice shell  and radar altimetry (REASON) data. The geodetic information that is of particular interest for interior science includes tidal deformation, shape-determination, librations, obliquity, as well as local gravity anomalies. The tidal response of Europa has been addressed in the previous section. The remaining observations are briefly described here.The shape of Europa provides insight into the structure and thickness of its ice shell  in principle might be sufficient to determine whether the crust is decoupled from the silicate mantle (Verma and Margot Longer-period librations (>10 days) driven by the Laplace resonance can be even larger; the maximum amplitude is over 1 km at a 482-day period  may lead to surface thermal anomalies. Double ridges in particular are promising locations for thermal anomalies  and trace organics and salt derivatives (Na and K). MASPEX measurements of the composition of low-weight organic volatiles as well as potential ice grains may point to the presence of clathrate hydrates in the crust  over a 0.1–5 μm spectral range. EIS color data can reveal color centers characteristic of irradiated chlorides. Oceanic material that erupted onto the surface  will be sputtered by high-energy particles and then sampled by MASPEX and SUDA. Together with Europa-UVS, these instruments will measure the abundance of key exospheric species  and a phase delay. This response depends on three parameters: the depth to the ocean, the electrical conductivity of the ocean, and the ocean thickness. In order to obtain all three ocean parameters, the response of the ocean at three widely separated frequencies is required. Indeed, nature does provide strong signals at three frequencies, the synodic rotation period of Jupiter , the second harmonic of the synodic rotation period  and the orbital period of Europa  that can be used to determine the properties of the ocean.The normalized amplitude see Fig.  varies sIn an idealized case, these three investigations alone would provide us with a solution to the three quantities identified in the Europa Clipper’s Level-1 science requirements. However, such precision would require both that the measurements themselves have zero uncertainty  and that the equations are linearly independent. Additional information to resolve this potential inherent nonlinearity is provided in the form of the auxiliary measurements described in Sect. combination of measurements provides a much more complete picture. Figure Although no single instrument can fully characterize the ice shell, a Static gravity coefficients constrain the moment of inertia  and thus the combined thickness of the ice shell plus ocean . Unlike the In this particular example, it is the combination of static gravity and magnetometry that together provide the main constraints on the shell and ocean thickness, giving combined uncertainties of ±5 km and ±10 km, respectively. But in other hypothetical examples, other techniques will become important. For instance, if the ice shell is thin (<10 km) then the magnetometer uncertainties will prevent a useful shell thickness estimation, but in this case the radar may be more likely to penetrate to the base of the shell and provide a direct measurement. Multiple measurements also provide some redundancy in case of unanticipated instrument failure.Auxiliary measurements, not shown in Fig. Although more challenging, multiple measurement techniques may also provide insight into the deeper interior. Local magnetic anomalies would be evidence for the existence of a core, while departures from hydrostatic equilibrium and/or large gravity anomalies could be indications of a cold, rigid interior. Conversely, a shell only a few km thick would imply a highly deformable interior; this would also give rise to a significant lag in the While multiple investigations directly constrain the ice shell thickness, they address different aspects of it. As an example, magnetic induction looks at the depth to the ocean, which depends on the total ice shell thickness. Subsurface sounding could provide this measurement if unambiguous detection of the ice–ocean interface was possible, which is however unlikely  properties, and indirectly on the near-surface thermal gradients. Such a technique has already been applied to the Galileo data. However, detailed topography data is available only for a limited set of sites . On the other hand, gardening by micrometeorites locally exposes fresh material on a similar scale, which can help entangle surficial effects and reveal the true nature of material sourced from the deep interior. The composition of most materials should be preserved in the ejecta blanket, except maybe for fragile material like organics  is introduced into Europa’s exosphere  could have been sufficiently high for clathrate hydrates to form in abundance (Bouquet et al. Geological interpretation (e.g., Figueredo and Greeley An environment that contains the chemical ingredients and physical conditions clement for life is defined as habitable (see Vance et al. Ocean depth and salinity are important drivers for habitability, as these inform ocean composition and constrain the chemical pathways available for a putative biosphere. While Europa Clipper is not able to measure the composition of fluids directly at the seafloor, surface compositional measurements (see Becker et al. If properties of the ice shell allow radar sounding to penetrate to the base of the ice shell Sects. , 2.2, EuMore broadly, constraints on, and variations in, the total ice shell thickness through radar sounding, magnetic induction, and gravity science Sects.  and 2.2 The total ice shell thickness is, in part, a function of the planetary heat budget, which is an important parameter in constraining the energy available for life (see Vance et al. Relatively large brine reservoirs (potentially Smaller-scale reservoirs (The Level-1 science objectives for the Europa Clipper mission describe three global parameters that are of particular interest to characterize the interior of Europa: the global mean thickness of the ice shell, the mean thickness of the subsurface ocean, and the salinity of the ocean. Measuring each of these quantities to an uncertainty of ±50% or less will enable evaluation of the habitability of this ocean world.In pursuit of these measurements, the payload on Europa Clipper includes three main investigations that are sensitive to combinations of the above parameters. The magnetic induction experiment will provide constraints on the extent and conductivity of the ocean, and the depth of the ocean below Europa’s surface. These can translate into constraints on the ice shell thickness and the salinity of the ocean. The subsurface sounding experiment characterizes the shallow subsurface and will constrain the thermophysical structure of the ice shell. These will result in an estimate of the minimum thickness of Europa’s ice shell and narrow down the thickness of the conductive portion of the ice. The tidal deformation measurements are sensitive to a combination of the thickness of the ice shell and its rigidity, providing an additional independent constraint on the thickness of the elastic portion of the ice shell.While each of these investigations alone will reveal critical information about the interior of Europa, none of them can provide a comprehensive view. Together, they support each other and are highly complementary. Combining multiple datasets is a powerful way of characterizing the interior of Europa and habitability of its subsurface ocean. These investigations are supplemented by a variety of ancillary investigations that can further reduce ambiguity and provide a unique view of the interior of one of the most compelling ocean worlds known to planetary science.


The results indicate that the unstructured region of PTP1B (300-400 amino acids) is very important both to obtain optimal inhibitory results and propose classical inhibition mechanisms (competitive or non-competitive) through kinetic studies. The IC50 calculated for ursolic acid and suramin using hPTP1B1-400 are around four and three times lower to the short form of the enzyme, the complete form of PTP1B, the one found in the cytosol (in vivo). On the other hand, we highlight the studies of enzymatic kinetics using the hPTP1B1-400 to know the type of enzymatic inhibition and to be able to direct docking studies, where the unstructured region of the enzyme can be one more option for binding compounds with inhibitory activity.In the present work, we studied the inhibitory and kinetic implications of classical PTP1B inhibitors  using three enzyme constructs (  In recent years, the updated classification of diabetes mellitus (DM) published by the American Diabetes Association (ADA) in 2021 identifies four types of diabetes. (1) Type 1 diabetes , (2) Type 2 diabetes (due to a progressive loss of adequate b-cell insulin secretion frequently on the background of insulin resistance), (3) Specific types of diabetes due to other causes, and (4) Gestational diabetes mellitus (diabetes diagnosed in the second or third trimester of pregnancy that was not overt diabetes prior to gestation)Due to the multifactorial nature of T2DM and the variety of molecular targets of the metabolic pathways associated with its aetiology, no specific pharmacological molecular target suggests a definitive treatment for this disease. However, various pharmacological targets for its treatment have been identified, such as dipeptidyl peptidase-4 enzyme (DPP-4), free fatty acid receptor 1 (FFAR1), G protein coupled receptors (GPCRs), α-Glucosidase, peroxisome proliferator-activated receptor (PPAR), augmenter of liver regeneration (ALR), G-protein coupled receptor for glucagon (GCGr), sodium-glucose linked transporter (SGLT), Phosphoenolpyruvate carboxykinase (PEPCK), and PTP1B, among the most importantThe phosphorylation/dephosphorylation of tyrosine residues is a mechanism for regulating the activity of proteins at the cellular level; it is essential for the normal functioning of signal transduction networks associated with the receptors of different hormones, cytokines and other bioactive moleculesPTPN1 gene (locus 20q13), whose amino acid sequence includes 435 residues (∼50 kDa) distributed in three structural domains: a highly conserved N-terminal catalytic domain known as PTP domain (PTP1B1-300), an intrinsically disordered regulatory domain also known as proline-rich domain (PTP1B301-400), and a hydrophobic C-terminal signalling domain (PTP1B401-435) that directs the protein to the endoplasmic reticulum (ER)1-300) is the target site for developing competitive, bidentate and allosteric inhibitors. Finally, the regulatory domain (PTP1B301-400) is suggested as a second target site of allosteric inhibition. This second allosteric site is critical for interacting with potential inhibitors and enhancing their inhibitory potencyPTP1B is a monomeric cytosolic protein encoded by the 1-300 and PTP1B1-321,1-400 is the one found in vivo.Since the PTP1B catalytic domain has only been resolved by X-ray diffraction, the protein forms used in most enzymatic assays and computational studies are PTP1B,,,This phosphatase negatively regulates the insulin signalling pathway, promoting the dephosphorylation of phosphotyrosines (Tyr) in the β-subunit of the insulin receptor and probably in the IRS-1/2 proteinThe insulin released from the pancreatic beta cell is transported into the cell, and it binds with its receptor producing the insulin-IR complex. Then, the intracellular part of the receptor is autophosphorylated, turning into an active kinase (sensitization). The abnormal signalling causes stimulation of PTP1B, which is involved in the desensitisation of the receptor by dephosphorylation. Therefore, inhibition of PTP1B has been considered as a potential drug target for the design of promising inhibitors. The effect of such inhibitors consists in delaying the receptor desensitisation, prolonging insulin effect for the treatment of diabetes II,Increased PTP1B activity in peripheral tissues appears essential for establishing insulin resistance, as suggested by numerous studies. This enzyme’s activity was increased in the muscle tissue of non-diabetic obese individuals suffering from insulin resistance,,in vitro and in silico experiments to study, design and discover new potent and selective inhibitorsThe background shows that PTP1B is a crucial protein in glucose homeostasis and is involved in the molecular mechanism of insulin resistance, a relevant condition in the pathogenesis of T2DM. Therefore, PTP1B can be an important therapeutic target in T2DM and other metabolic disorders such as obesity and metabolic syndromehPTP1B1-400). Despite the fact that the last one is challenging due to the homology of the PTP domain among the PTPs family members, it can oppositely provide an opportunity to discover activators from related PTPs inhibitorshPTP1B  with the inhibitors ursolic acid (UA), chlorogenic acid (CGA), suramin (SUR), sodium orthovanadate (SO), and Compound 5 b a derivative of 18β-glycyrrhetinic acid and docking studies to complement the experimental data of the enzyme-ligand complexes. The inhibitors used were chosen because some are classical inhibitors and are used as positive controls in many previous works and because they present different types of inhibition . The results indicate that the unstructured region of hPTP1B (300–400 aminoacid) is crucial to obtain reliable inhibition and kinetic parameters. On the other hand, kinetic studies are of great value in establishing the type of inhibition of bioactive compounds of PTP1B.There are some essential aspects in the search for PTP1B inhibitors; the most important are the potency, the type of inhibitor, and their selectivity. The first two can be performed using the appropriate enzyme form (hPTP1B) coding gene sequence PTPN1  codon optimised for Escherichia coli was obtained from OriGene . The expression vector pET-28a(+) was obtained from Invitrogen . E. coli strain DH5α and BL21 (DE3) were purchased from Invitrogen . DNA extraction was performed with Kit QIAprep Spin Miniprep . The forward-reverse pair primers for the expression of the three hPTP1B constructs, IPTG, imidazole, dithiothreitol (DTT), p-nitrophenyl phosphate (pNPP), chlorogenic acid (CGA), ursolic acid (UA), suramin (SUR), sodium orthovanadate (SO) were obtained from Sigma-Aldrich . Compound 5 b was synthesised from 18β-glycyrrhetinic acid according to the procedure of Ledy De-la-Cruz-Martínez and collaboratorsThe full-length of human PTP1B  and C-terminal domain (hPTP1B1-400), were cloned by PCR from full-length hPTP1B coding gene (PTPN1) optimised for E. coli and inserted into a pET-28a(+) vector at the 5′NdeI and 3′HindIII restriction sites, resulting in a new construct pET-28a(+)-PTPN1. Three forward-reverse (Fwd-Rev) primer pairs were designed for each hPTP1B coding gen to construct so: Fwd 5′-TCATGGGTGATAGTTAAGTTCAGGACCAATG-3′ and Rev 5′- CATTGGTCCTGAACTTAACTATCACCCATGA-3′ to clone hPTP1B1-285, Fwd 5′- CTGGAACCGCATAATTGAAAGTGCCGTGAATTT-3′ and Rev 5′- AAATTCACGGCACTTTCAATTATGCGGTTCCAG-3′ to clone PTP1B1-321, and Fwd 5′- TGGTCATATGGAAATGGAAAAAG-3′ and Rev 5′-TGCAAGCTTAGTCTTCATCTTTTTC-3′ to clone hPTP1B1-400. The PCR amplification product size was confirmed by agarose gel electrophoresis. E. coli strain DH5α was transformed with all of the three PTP1B gene constructs. DNA concentration was determined by measuring the absorbance at 260 nm in a UV-Vis spectrophotometer . Finally PTP1B coding sequence gene construct was confirmed by DNA sequencing in the Unit of Molecular Biology, Institute of Cellular Physiology at UNAM (Mexico).The three constructs of hPTP1B gene construct was sequenced , they were transformed into E. coli strain BL21 (DE3). Transformed E. coli cells were grown in LB media (pH 7.5) containing kanamycin (30 mg/mL) at 37 °C for 6 h with continuous agitation (250 rpm). Once the cultures reached an A600 of 0.6 (about 6 h), protein expression was induced with 1 mM IPTG at 37 °C, 250 rpm for 6 h. After centrifuge , the grown and IPTG-induced cultures and bacterial pellet were resuspended in Tris buffer (pH 6.8) and lysed by sonication  in an ice-water bath with an ultrasonic processor . The cell lysate was centrifuged , the supernatant was filtered with a PVDF membrane (pore size 0.45 µm)  and loaded onto a HisTrap HP immobilised metal affinity chromatography (IMAC) column . The column was equilibrated with 50 mM Tris, pH 6.8, with three column volumes. His-tagged protein was eluted with Tris 50 mM and 300 mM Imidazole with one column volume. PTP1B phosphatase activity of the collected fractions was confirmed by the pNPP activity assay (see below). Fractions containing hPTP1B were dialysed in 50 mM Tris, pH 6.8. The purity of the protein was followed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) using a 12% resolving gel.After DNA of each hPTP1B activity assays using para-nitrophenyl phosphate (pNPP) as substrate were performed to determine the intrinsic catalytic activity of all three hPTP1B constructs  confirmed in the purification process, and the in vitro inhibitory effect of the tested compounds. Initial experiments were carried out to set up suitable conditions for the following enzyme activity assays. The optimum substrate and enzyme concentration were determined by testing different concentrations of each. pNPP activity assays were carried out in a final volume of 100 µL of Tris 50 mM, pH 6.8, containing purified hPTP1B 66 nM and pNPP 0.25 mM. Enzyme solutions containing pNPP and inhibitors were incubated at 37 °C for 15 min. The hydrolysis product’s absorbance, para-nitrophenol (pNP), was measured every 60 s for 30 min at 405 nm using a 96-well microplate absorbance reader (Accuris). Absorbance values were expressed in terms of molar product using a pNP extinction coefficient of 18,000 M−1 cm−1hPTP1B constructs  were assessed at the previously established optimal conditions  using hPTP1B nM. IC50 assays were carried out in the assay buffer at fixed enzyme concentration (66 nM of each hPTP1B construct), pNPP 0.25 mM, and ten increasing concentrations of each inhibitor (diluted in 100% DMSO) as follows: UA in 5 µM increments (5 to 50 µM), CGA in 0.4 mM increments (0.4 to 4.0 mM), and SUR in 1.0 µM increments (1.0 to 10 µM). The negative control was prepared with the enzyme and substrate in the absence of an inhibitor. The experiments were performed in triplicate. The percentage of inhibition was plotted as a function of the inhibitor concentration. IC50 was calculated by regression analysis using PTP1B is the percentage of inhibition, 100A is the maximum inhibition, i is the inhibitor concentration, 50IC is the concentration required to inhibit the enzyme’s activity by 50%, and s is the cooperative degree.The inhibitory effect of ursolic acid (UA), chlorogenic acid (CGA), and suramin (SUR) on the three purified 50, the assays to determine the enzyme kinetic parameters and inhibition mechanism were conducted in the same experimental conditions but varying concentrations of pNPP in 0.1 mM increments (0.1–0.5 mM), and using five increasing concentrations of each inhibitor according to previously determined IC50 values, as follows: UA 0, 1.5, 3.0, 4.5 and 9.0 µM; CGA 0, 0.5, 1.0, 1.6 and 3.0 mM; and SUR 0, 1.0, 2.0, 3.0 and 5.0 µM. The negative control was prepared with the enzyme and substrate in the absence of an inhibitor. The experiments were performed in triplicate. Enzyme inhibition kinetic parameters mK and maxV were obtained by fitting data to the Michaelis-Menten model using In a similar way to the ICmaxV is the maximum velocity, x is the inhibitor concentration, and mK is the Michaelis constant.Fitting data determined PTP1B inhibition mechanisms to a nonlinear regression curve according to the equations defined for competitive, mixed, and uncompetitive inhibition models . The pdb file was downloaded from the following link: https://alphafold.ebi.ac.uk/entry/P18031hPTP1B1-400 and compounds. For stereoisomeric compounds, the conformer that presents greater stability after minimisation was coupled, maintaining the torsion angles detected by AutoDockTools. Polar hydrogen atoms and the Kollman united-atom partial charges were added to the protein structures. In contrast, Gasteiger-Marsili charges and rotatable groups were automatically assigned to the structures of the ligands. We use Autodock Vina to do the docking, covering the entire enzymeThe structural model of the hPTP1B1-400 protein was obtained from AlphaFold Protein Structure Database developed by DeepMind and EMBL-EBI  to evaluate different types of inhibitors (competitive and non-competitive). hPTP1B1-285 and hPTP1B1-321 represent the short form of hPTP1B that includes the N-terminal catalytic domain. hPTP1B1-400 constitutes the long form of the protein that includes the intrinsically disordered C-terminal regulatory domain. hPTP1B1-285, hPTP1B1-321, and hPTP1B1-400, respectively. The Km of the sutrate (pNPP) is 16.37 ± 1.55, 15.66 ± 1.68, and 2.03 ± 0.11 mM for the hPTP1B1-285, hPTP1B1-321, and hPTP1B1-400, respectively.hPTP1B. The IC50 observed for CGA is similar in all three enzyme forms. However, for the UA and SUR, the IC50 estimated using hPTP1B1-400 is around four and three times lower concerning the shorter forms (PTP1B1-285 and PTP1B1-321), respectively (50 varies depending on the length of the hPTP1B used to perform the activity assay (short or long). Therefore, using the enzyme in its complete form , which is the one found in vivo, has positive repercussions in calculating this parameter.ectively . These rhPTP1B1-285. 3-bromo-4,5-bis-1,2-benzenediol (BDB)hPTP1B1-321. In recent years the inhibitors Trodusquemine,hPTP1B1-321 and hPTP1B1-400). For the Trodusquemine, the reported Ki are 4.0 and 0.6 µM for the short and long forms, respectively, about 6-fold lower with hPTP1B1-405. The same happens with celastrol, where IC50 are reported using PTP1B1-298 (IC50=4.8 µM) and PTP1B1-393 (IC50=2.1 µM), double the value using the short form.Many of the inhibitors reported in past years have used the short form of PTP1B to perform inhibition or kinetic assays. For example, N-aryl oxamic acid1-400, and the IC50 reported using this enzyme is lower, so inhibitors reported with the short version of PTP1B may have been overestimated.hPTP1B1-400. For the CGA, the Ki is in the order of mM (1.03 mM), and the type of inhibition is competitive. Previous studies have reported non-competitive inhibition using hPTP1B1-301 and hPTP1B1-321,Ki =4.0 µM). However, a competitive and non-competitive type of inhibition has been previously reported using hPTP1B1-3211-298,,Ki is in the nanomolar order (Ki =89 nM), and the type of inhibition was uncompetitive an order of magnitude higher Ki (0.38 µM) and a type of competitive inhibition have previously been reported for this inhibitor, using hPTP1B1-321. These discrepancies in the inhibition mechanisms reported by different authors may be due to the type of PTP1B used in the kinetic study or the statistical adjustments that are sometimes minimal. For example, for compound 5b a glycyrrhetinic acid derivative, the R2 are minimal for 4 different types of adjustment: competitive (R2=0.933), non-competitive (R2=0.978), uncompetitive (R2=0.996) and mixed (R2=0.975). On the other hand, kinetic studies allow us to direct computational theoretical studies such as docking since, knowing the type of inhibition, we can focus the conformational search for the inhibitor in particular regions of the enzymes.The kinetic parameters are fundamental since we can determine the affinity of an inhibitor for the enzyme and its possible mechanism of inhibition. With this information, we can conduct directed docking studies and obtain three-dimensional models of the enzyme-inhibitor complex. For example, hPTP1B1-400 ; the results are shown in Ki theoretical) are in the range of magnitude similar to the experimental values , indicates that this parameter using the complete enzyme is lower for the inhibitors AU and SUR. Therefore the IC50 of previously reported inhibitors that used the short forms of PTP1B may be underestimated. The complete form of hPTP1B is the one that is found in vivo in the cytosolic space, and it seems that the unstructured region plays an important role in the modulation of the enzyme’s activity. Another critical aspect of PTP1B inhibitors is knowing their inhibition mechanism, which can be known indirectly using enzyme kinetics studies, which can additionally be used to guide docking studies or molecular dynamics simulation. Molecular modelling studies can help improve known PTP1B inhibitors by analysing interactions at the molecular level of enzyme-inhibitor complexes and proposing synthetic derivatives. Based on the results obtained in this work, we can highlight some relevant points, such as (1) The importance of using the hPTP1B1-400 enzyme to get binding and kinetic parameters. (2) Carry out kinetic studies of the inhibitors to describe their mechanism of action. (3) Conduct in silico studies based on experimental studies, and (4) Redesign non-competitive inhibitors with low Ki (high potency) to favour selectivity and potency for PTP1B.This work highlights the importance of using


By combining observations, Coupled Model Intercomparison Project historical simulations, and pacemaker climate model experiments, we find evidence that the synchrony between the sea ice decadal oscillation and Pacific Quasi-Decadal Oscillation is linked to atmospheric poleward-propagating Rossby wave trains excited by heating in the central tropical Pacific. These waves weaken the Amundsen Sea Low, melting sea ice due to enhanced shortwave radiation and warm advection. A Pacific Quasi-Decadal Oscillation-based regression model shows that this tropical-polar teleconnection carries multi-year predictability.Over the satellite era, Antarctic sea ice exhibited an overall long-term increasing trend, contrary to the Arctic reduction under global warming. However, the drastic decline of Antarctic sea ice in 2014–2018 raises questions about its interannual and decadal-scale variabilities, which are poorly understood and predicted. Here, we identify an Antarctic sea ice decadal oscillation, exhibiting a quasi-period of 8–16 years, that is anticorrelated with the Pacific Quasi-Decadal Oscillation ( A decadal-scale oscillatory pattern is identified that is a dominant mode of Antarctic sea ice variability. This mode is primarily driven by tropical-polar connections, offering insights into the multi-year predictability of Antarctic sea ice. It is characterized by complex variations on a variety of timescales superimposed on an overall long-term increasing trend during the satellite era9. Despite this, the quick retreat of Antarctic sea ice from 2014 to 2018 has garnered a lot of attention13. These long-term fluctuations have been connected to dynamic processes in the Southern Ocean17 and large-scale climate modes in the Pacific and Atlantic Oceans23. For example, a previous study suggested that the increasing trend of Antarctic sea ice in the 2000s is driven by the Interdecadal Pacific Oscillation (IPO)18, which shows drastic multidecadal fluctuations (20–30 years). On an interannual period (2–8 years), the Southern Annular Mode (SAM) and a circumpolar zonal wave-3 (ZW3) are primary local circulation patterns that affect the variability of sea ice through wind-driven dynamic and thermodynamic processes26. Remotely, the El Niño-Southern Oscillation (ENSO)-related tropical Pacific SST warming causes contrasting changes in sea ice concentration (SIC) over the Weddell and Ross Seas, referred to as the Antarctic sea ice dipole29. Uncovering the complex variations of Antarctic sea ice is a basis for advancing its prediction. However, the quasi-decadal (8–16 years) variability and the recent drastic fluctuations in sea ice have not been fully understood, and accurate prediction of Antarctic sea ice remains challenging30. The interannual sea ice predictability only reaches three years using intermediate complexity climate models32. Meanwhile, the decadal prediction of Antarctic sea ice is far from skillful since most CMIP5 models are unable to reproduce the observed increasing trend34. A recent study demonstrated that the predicting skill of sea ice over the Ross Sea on the decadal scale is still very limited in spite of refined model initialization30. Thus, there is an urgent need to improve the Antarctic sea ice predictability on the decadal scale.Antarctic sea ice plays a crucial role in the exchange of heat, momentum, and water masses, modulating global atmospheric and oceanic circulations35, providing an important source of predictability36. Other than the interannual and multidecadal modes, the quasi-decadal oscillating signals in the Pacific are less understood and more pronounced on the regional scale39. One of these decadal modes is located over the central tropical Pacific, where the sea surface temperature (SST) exhibits alternative warming and cooling phases, with a quasi-period of 8–16-yr, referred to as the Pacific Quasi-Decadal Oscillation (PQDO)41. Previous studies regarded the PQDO as a non-linear component of ENSO42, while other studies also suggested that the dynamical coupling between the tropical SST heating and extratropical atmospheric forcing associated with the Kuroshio Extension plays a role47. It has been conclusively proved that the PQDO is an independent quasi-periodic mode and fundamentally different from ENSO42. Also, the PQDO can be differentiated from the IPO in terms of their temporal scales48. Moreover, the PQDO has profound influences on regional climate variability on the quasi-decadal time scale, such as tropical cyclones and inland precipitation52. Investigating the climate impacts of the PQDO would enlighten our understanding of quasi-decadal climate variations and improve climate predictability.Low-frequency oscillatory phenomena have been observed in the Pacific basin on a variety of temporal scalesIn this study, we investigate the decadal variability in Antarctic sea ice and examine its quasi-periodic nature. The underlying mechanism is inspected in historical Coupled Model Intercomparison Project Phase 6 (CMIP6) simulations and a dedicated pacemaker experiment conducted with the ICTPAGCM-NEMO coupled model. A PQDO-based sea ice regression model is further constructed to estimate the SIC changes in the next decade.53 and Weddell Seas while decreasing over the Amundson and Bellingshausen Seas, which corresponds well with the observed trend pattern . The Ross-Amundsen Seas SIC strongly coincides with the PC2 (r = 0.88), consistently showing a quasi-period of 8–16 years and a spectral peak at roughly 12–14 years , explaining 19% variance of Antarctic SIC and exhibiting a spectral peak at 12–14 years , further suggesting that the Ross-Amundsen Seas SIC is representative of the decadal component of Antarctic sea ice variability, with a notable quasi-period of 8–16 years. We, therefore, refer to it as the Antarctic decadal oscillation (abbreviated AADO). The AADO index (see Index definitions in Methods) using the OISST and the HadISST SIC datasets  on the annual mean SIC (within 50°S–90°) derived from the NSIDC dataset for the period 1981–2020. The leading mode of EOF explains about 16.9% of the variance . The lead-lag correlation between SAT and SIC indicates that the SIC melting driven by preceding and contemporary SAT warming is stronger than its feedback to maintain the anomalous SAT  and, consequently, SIC decline (r = −0.87). We evaluate the relative contributions of shortwave radiation and temperature advection to the SIC changes using standardized partial regression coefficients  from a multivariate regression model of the AADO. It suggests that the radiative heating term may play a more important role. Based on the above analysis, the ASL is an essential local atmospheric forcing responsible for the changes in SIC via the thermodynamic process. The ASL exhibits a consistent 8–16-yr quasi-period through wavelet analysis . However, the quasi-periodicity found in the AADO is obscure in those two variables . Both subsurface temperature37. The cross-wavelet between the PQDO index (see Methods) and the AADO index  of SST variance Fig. . The cendex Fig.  indicatedex Fig.  with a c21. Such a tropical-polar teleconnection pathway consists of alternating low/high pressure centers located over New Zealand and the Amundsen Sea  and the anticorrelated relationship between the PQDO and AADO (r = −0.53)  is conducted to inspect the direct response of Antarctic sea ice to the PQDO. The ICTP-NEMO coupled model has capability to reproduce the observed tropical-polar teleconnection and the decadal oscillation in the Ross-Amundsen Seas SIC  Fig. . The SIC53) Fig. , as thatIn CMIP6 historical simulations  that replicate a strong correlation between the PQDO and AADO as Group 1, whereas another four models  that indicate poor correlation as Group 2. The criterions selecting models are introduced in the Supplementary Table ice Fig. . The troice Fig. . As a re48. It exhibits a spectral peak within 12–14 years, which is statistically significant at the 95% confidence level  since its quasi-periodicity only emerges till the late 1950s60–2020 st denotes year. a and b are regression coefficients, and c1 and c2 are residual. The parameter τ, estimated using the lagged auto-correlation of the PQDO index, indicates the time length of the PQDO phase transition. The oscillating nature of PQDO is shaped by the lagged influence of nonlinear dynamical heating related to ENSO nonlinearity42, with a maximum lagged auto-correlation at approximately seven years  and a consistent spectral peak of 12–14 years. The PQDO excites a poleward propagating Rossby wave train, with a significantly weakened ASL at the downstream. The changes in local atmospheric circulation further embed the PQDO signal into the sea ice variation via thermodynamic feedbacks. The mechanism has also been consistently reproduced by the Central Pacific pacemaker experiment and CMIP6 historical simulations.In this study, we identify a decadal mode of Antarctic sea ice variability, referred to as the AADO. The AADO is modulated by the central tropical Pacific SST (the PQDO), exhibiting synchronized decadal fluctuations 58, which shows considerable loading over the Northeast Pacific on decadal scales (r = −0.69), implying that Antarctic sea ice may be further influenced by the decadal signals from the extratropical North Pacific.The PQDO-AADO relationship can be differentiated from the ENSO- and IPO-related tropical-polar teleconnections in terms of temporal behaviors. For ENSO, it variates primarily on interannual scales59. It is calibrated from different sensors and produces consistent long-term data to allow the analysis of sea ice variability. We also employ the OISST60 and the HadISST61 SIC datasets (both at a 1° resolution) in comparison with the NSIDC data. The sea ice motions are observed sea ice drift derived from the NSIDC Polar Pathfinder Daily 25 km EASE-Grid Sea Ice Motion Vectors, Version 4. The sea ice motion vectors are derived from satellite-based observation, buoy position data, and NCEP reanalysis data and have been widely used in previous studies63. This dataset has a spatial resolution of 25 km and covers from 37°S to 90°S. The data is available for the period 1978–2021. The SST data used to define the PQDO index is obtained from the Extended Reconstruction SSTs version 5 (ERSSTv5)64, with a spatial resolution of 2° × 2°. The atmospheric data  is derived from the ERA5 reanalysis65 (regrided to the T63 grid in this study). Note that the radiative fluxes from the ERA5 reanalysis shows a large bias in the Southern Ocean66, while the one from the NCEP2 Reanalysis (used in this study) has better performances67 (defined as positive downward)68. The subsurface temperature is used for the period 1981–2020 derived from the EN4 reanalysis69, which has a spatial resolution of 1° × 1° and 42 layers. The historical simulations from 29 CMIP6 models  dataset. It covers the range from 45°S–90°, with a spatial resolution of 1° × 1°. The SIC is estimated from satellite-based observation of passive microwave brightness temperaturesThe AADO index is defined as the area-weighted average of SIC over the Ross-Amundsen Seas .52.The PQDO index is defined as the area-weighted average of sea surface temperature in the central tropical Pacific . This definition is consistent with previous studies18.The IPO index is defined as the PC2 of 8-yr lowpass filtered Pacific SST , which is similar to the definition in the previous studyhttps://psl.noaa.gov/enso/dashboard.html.The Nino 3 index is defined as the area-averaged SST anomalies (ERSSTv5) over the central-eastern tropical Pacific . It is downloaded from http://o3d.org/npgo/.The NPGO index is defined as the second dominant mode of sea surface height variability in the Northeast Pacific, which can be downloaded from 71 with a Morlet wavelet base, which has been widely employed in previous studies52. The cross-wavelet spectrum is also used so that we can quantify the coherence of periodicities as well as phases between time series72. The significance of the power spectrum is also examined using the Monte Carlo Singular Spectrum Analysis73. Here we use an auto-regressive model to fit the observed data and generate 5000 realizations with the same parameters to show if the spectral peak is a real containing signal within a limited sample size.This study focuses on quasi-decadal variability, so the annual mean of monthly data is calculated before analysis. To identify the quasi-periodicities, we apply the local wavelet spectrum method54, which is estimated using the following equations:We examine the separation of EOFs, following the “rule of thumb” in ref. eff) is estimated by:In this study, we employ an 8-yr lowpass filter to isolate the decadal SIC variation while removing the interannual signal, such as ENSO. The statistical significance of the correlation coefficient is evaluated by a two-tail Student’s t-test, where the effective number of degrees of freedom  version 3 model77, which includes a sea ice component (LIM version 3)78. The ICTPAGCM has eight vertical levels and a horizontal resolution of T30 (3.75° × 3.75°), with simplified parameterization schemes. The model is computationally efficient, while it exhibits on-par performance in simulating large-scale features and climate variability compared to state-of-the-art models76. The NEMO model solves primitive equations (z-coordinate) on a tripolar ORCA2 grid , and its physical ocean component contains both dynamics and thermodynamics. Considering the tight interaction between sea ice and the underlying ocean, the ocean dynamics is interfaced with the sea ice component that takes into account ice dynamics, thermodynamics, subgrid-scale thickness variations, and brine inclusions79. The ocean and sea ice components in the NEMO model are coupled to the ICTPAGCM via the OASISv3 coupler80, allowing us to inspect the complex interactions within the ocean-atmosphere-sea ice system over the Antarctic Seas.Here we use an intermediate complexity atmospheric general circulation model from the International Centre for Theoretical Physics 81. The carbon dioxide concentration is fixed in the CP_EXP so that we can isolate the internal forcing on the sea ice decadal variability.In the pacemaker experiment, the ICTPAGCM-NEMO coupled model is relaxed to the observed monthly varying SST (ERSSTv5) over the central tropical Pacific (10°S–10°N and 165°E–165°W), while allowing the model to freely evolve outside the central tropical Pacific region (referring to as CP_EXP). The pacemaker experiment aims to inspect the PQDO-related changes in atmospheric circulation and the associated ocean-atmosphere-sea ice coupling over the Antarctic. The SIC is modulated by dynamic and thermodynamic processes in the atmosphere as well as the underlying ocean. The model is conducted from 1955 to 2022 . The experiment is started from an already spin-up state (for about 1000 years) with stabilized global mean surface air temperature, sea ice cover, and top-of-atmosphere net energy flux, while an additional 26-year is for the pacemaker experiment to spin upSupplementary materialPeer Review File


The daily average (cloudy day and rainy day) sensible heat flux in the two sites was 39.5 W·m−2 (FPV site), 19.2 W·m−2 (REF site), respectively. The latent heat flux was 53.2 W·m−2 and 75.2 W·m−2 on counterpart. The water body generally absorbs heat from the air (daily average ∆Q was 16.6 W·m−2) in the FPV site on a sunny day. The driving force of sensible heat flux in the FPV site was governed by the temperature of the FPV panel under sunny and cloudy conditions. The latent heat flux was determined by the product between wind speed and water-atmosphere temperature difference.The underlying surface was the important media of air-lake interaction by transferring energy. The deployment of photovoltaic arrays on the lake has formed a new underlying surface type. But the new underlying surface is different from the natural lake. The impact of fishery complementary photovoltaic (FPV) power plants on the radiation, energy flux, and driving force is unclear. Therefore, the analysis of radiation, energy flux, and driving force by comparing the difference in the two sites under various synoptic conditions. The results indicated that the radiation components are not significantly different in the two sites under diverse synoptic conditions. The downward shortwave radiation (DSR) and net radiation ( Therefore, the original balance of radiation and energy in the local region was broken by the deployment of utility-scale PV plant. Synoptic conditions immediate vicinity PV plant were affected by the change of original level of radiation and energy. However, few studies have been reported in these aspects. Studies of the impact of PV plant on local microclimate are accelerating in this disquisition direction. Taking temperature as an example, different scholars’ analyses of the impact of PV plant on temperature are shown in Table The utility-scale photovoltaic (PV) power plant is accelerating to achieve carbon peaking and carbon neutrality goals in China. The development of PV plants occupies a large amount of land resources that are important to the Chinese. Meanwhile, the land-use pattern, the underlying surface, and land–atmosphere energy transmission have been altered by the presence of utility-scale PV plant9, which provides the possibility for direct observation of the flux on the required time and space scale10. It is the most accurate method when the underlying surface is uniform and the terrain is flat and the atmospheric conditions are stable11. Therefore, this method has been widely used in actual observations. Sun et al.12 analyzed the energy flux and water evaporation changes of lakes in the Badain Jaran Desert through one year (2012.03–2013.03) EC observational data. The results showed that the daily and seasonal characteristics of long-wave and short-wave radiation fluxes change is obvious. The average annual evaporation rate of the lake is about 4.0 mm·d−1, the cumulative annual evaporation rate is 1445 mm·a−1, and the cumulative annual evaporation is 10 times the cumulative annual precipitation. Potes et al.13 analyzed the lake-atmosphere interaction in Alqueva reservoir in the summer of 2014. During the study, the energy of the reservoir was mainly released in the form of sensible heat flux and latent heat flux. Xiao et al.14 studied the control mechanism of the interannual variability of subtropical lake evaporation, answered the reasons for the change of lake evaporation under the scene of climate warming based on the EC measurement data and the principle of energy balance. It shows that lake evaporation increases with the amount of the solar radiation absorption and incident long-wave radiation. In addition, the decrease in lake evaporation is mainly caused by the feedback effect, in which weaken the reflected long-wave radiation. Spank et al.15 analyzed the EC observation data of the largest drinking water Rappbode Reservoir in Germany for one season. The results showed that the diurnal variation characteristics of the sensible heat of the reservoir are different from that of the land surface. At night and during the day, the latent heat flux and evaporation are abnormally low in the waters where evaporation is not restricted. There are a lot of studies on lake radiation characteristics and fluxes using EC observation data, which provides the possibility to further explore the lake energy flux response and lake-air interaction under the background of climate change. On the one hand, the change of energy flux was analyzed by the EC due to the efficient accuracy and widespread use. In addition, the few studies of energy flux for FPV power plant were less reported. Therefore, the characters of energy flux in FPV power plant were dissected by the EC data to reveal the impact of PV panels deployment on lake surface energy balance in this paper. FPV power plant is a new type of using solar energy by deployment of solar panels on water surface. The development of FPV power plant is a make a breakthrough at harnessing solar power field because of the installed region without the land limitation. However, there is a big difference of property between solar panels and lake underlying surface. That is an integrated underlying surface after installing the solar panels on original area. Solar radiation and energy balance in local area were affected by the deployment of FPV power plant. It is well-known that the lake-atmosphere interaction is dominated by the balance of both radiation and energy. The change of radiation and energy balance further conducted on local synoptic condition. At present, there are many studies on the variation of radiation flux and energy flux in PV power plants16. But the characteristic of radiation and energy balance under different synoptic conditions for FPV power plant was less reported. Hence, our study fills this research gap maybe to amend the accuracy of solar radiation prediction due to our paper to consider the impact of weather condition on solar radiation.Eddy Covariance (EC) has few theoretical assumptions in the calculation process for the measurement of water and heat fluxThe characteristics of radiation and energy flux under different synoptic conditions for FPV power plant were analyzed in our paper. Meanwhile, the energy flux and its driving force and major environmental parameters were given to enhance understanding the interactive function between water surface and atmosphere after installing the PV arrays on lake. In addition, this study maybe helped to enhance the recognition of the impact of microscale climate on the solar radiation prediction.The trial was conducted on the Tongwei Huantai 10 MW Fishery Complementary Photovoltaic Demonstration Base. This base is located on the Yangzhong City, Jiangsu Province of Eastern China. Yangzhong is situated in the middle of the northern subtropical monsoon climate zone, with a mild climate, abundant rainfall and the same season of rain and heat. From January to December in 2019, the average temperature for Yangzhong was 17.1 °C, the annual precipitation was 791.8 mm, and the annual accumulated sunshine time was 1792.2 h. The changes of radiation and energy flux installed PV arrays on the lake were captured by comparing the results from the flux observation tower inside and outside FPV power plant. The study area and the location of flux observation tower were shown in Fig. The height of the flux observational tower is about 11 m for both two sites. The equipment of the flux observational tower for the FPV site is shown in Fig. Data collection of ECS starts on November 15, 2019, the high frequency data (10 Hz) are stored in a CR3000 data logger  and half-hourly mean flux are calculated online by the Eddy Pro software. The measuring devices were maintained in time every month to ensure the accuracy and quality of data.−3) is the air density, −1·K−1. 6 J·kg−1). And the parameters -1) and −1) are the deviations from the temporal averages of the air temperature, the specific humidity and vertical wind speed, respectively.The half-hourly flux data was performed field removal, trend correction, secondary coordinate rotation, Gill ultrasonic anemometer angle correction, time delay correction, ultrasonic false temperature correction of sensible heat flux, frequency response correction, and water vapor correction by Eddy Pro software (v7.0.6). Finally, the average sensible heat flux (H) and latent heat flux (LE) were calculated according to the EC method, as follows formula  and 2)..2).1\docAs net radiometer is less affected by the weather, the raw data of downward shortwave radiation , −1·K−1)17; The heat storage The vertical profile of the water temperature change was obtained by the three layers  water temperature observation, then the depth-weighted average water temperature is calculated to obtain the depth-weighted average water temperature change within a fixed time step (30 min). The formula  was increased  on sunny day. But Li et al. found that the albedo is decreased after deploying the PV arrays on lake20. Because the albedo of lake is higher than the PV panel materials. Therefore, the water environmental quality of lake maybe improved by the deployment of PV arrays. The albedo is higher to cause the eutrophication of water bodies21. Additionally, the deployment of PV arrays on lake can also the change of the thermal properties in two sites, which is mainly presented in the difference from the long wave reflection. The daily minimum of ULR in FPV site was 470.4 W·m−2 at 5:30, and ULR minimum appeared 30 min later in REF site (482 W·m−2) than in the FPV site later 30 min.August 16, 2020 was a typical sunny day, and the radiation flux curves in two sites were relatively smooth  or negative (19:00) was the same in two sites, and the DSR change was also synchronized with the net radiation.With the solar radiation increasing, the ULR in the FPV site was greater than in the REF site at 7:30. The ULR daily peak in the FPV site appears at 12:30 as 559.2 W·m−2 and 214.10 W·m−2, respectively. The average USR of the FPV site was 1.4 W·m−2 smaller than that of the REF site. The DLR trends in two sites are synchronized well, and the average in FPV site and the REF site is 420.08 W·m−2 and 416.64 W·m−2, respectively. The maximum impact of PV arrays on the radiation component is mainly presented in the difference of ULR in two sites. The PV panel heats up rapidly than the water with the increase of solar radiation because the specific heat of the PV panel (950 J·kg−1·K−1)22 is smaller than that of the water (4184 J·kg−1·K−1). ULR in the FPV site had been reaching the peak of the day at 12:00 with 505.7 W·m−2. On the contrary, the peak in the FPV site was lagged than the REF site and it appears at 14:00 as 469.5 W·m−2. The variation of URL in FPV site was greater than that of the FPV site with the solar radiation was ebbing away. ULR in the FPV site decreases significantly after 18:00 with reaching the minimum at 4:00 a day as 437.6 W·m−2.The variation of the radiation component was analyzed in two sites Fig. c,d for t−2 in the FPV site and 262.9 W·m−2 in the REF site, respectively. The daily variation of DSR presented a jagged fluctuation after the rain was starting at 11:00. In order to clearly compare the difference in radiation between the FPV site and the REF site, the variation of radiation components under different synoptic conditions was shown in Table The rainy day was selected on July 6, 2020. The change curve of radiation components in the two sites is shown in Fig. 23, grassland24, et al. The difference in radiation on various underlying surfaces is from the impact of aerosol, water vapor, terrain, and weather conditions on sunlight.In general, the deployment of PV arrays on the lake is forming a new underlying surface. The radiation characteristic change of FPV (one peak) is the same as the desert−2 and 56.38 W·m−2, respectively. The H with an average value of only 0.3 W·m−2 was smaller than LE during weak solar radiation before 7:30. Then, the H was greater than the LE and this process lasted until 14:30 because the PV panels heats up continuously with the solar radiation. This duration was reflected by the influence of the DSR change process on the H, and the rate of the H change was determined by the properties of the photovoltaic panel25. The daily average of ∆Q was 16.6 W·m−2, which means the water body generally absorbs heat from the air. Especially ∆Q > 0 from 6:30 to 16:30 was the water storage heat phase and other timespans were the water release of heat phase. Therefore, this heat change process plays an important role in maintaining the stability of the water environment.The variation of energy flux changes in the two sites is shown in Fig. −2, and the average LE in the REF site was 93.42 W·m−2. The LE in the FPV site was smaller than that of the REF site because the area on the lake of directing the solar radiation was reduced by the shading effect of the PV arrays. The overall change trend of the H in the FPV site was significantly greater than that of the REF site. But the solar radiation before 6:30 and after 19:00 was absent. Therefore, the H in the FPV site was smaller than that of the REF site. The H in the FPV site after 6:30increased with the solar radiation. it reached the daily maximum at 12:00 noon with 140.9 W·m−2. Subsequently the H decreased with the solar radiation decline. The change of H in the FPV site was significantly greater than that of the FPV site with the presence of solar radiation. The average of H in the FPV site and the REF site was 66.09 W·m−2 and 26.19 W·m−2 from 6:30 to 18:30, respectively. With the absence of solar radiation, the average of H in the FPV site and the REF site was 1.33 W·m−2 and 5.98 W·m−2, respectively. In general, the contribution of the impact of solar radiation on the H in the two sites was 98% (FPV site) and 77% (REF site), respectively. The impact of the PV array installation in the lake on the H is 1.5 times compared to the H of the natural lake. Therefore, solar radiation plays a decisive role in the change process of H for the FPV power plant.In cloudy weather, the average LE in the FPV site was 74.76 W·m−2 and 6.2 W·m−2, respectively. The variation of LE was the opposite of the rule of H. The LE in the two sites was 31.7 W·m−2 (FPV site) and 56.9 W·m−2 (REF site), respectively. ∆Q was negatively explained by the air temperature drop sharply for precipitation, which indicates that the air absorbs heat from the water body to achieve a water–air heat balance.The H data during the rainy weather period has been eliminated, and the average H was significantly lower than other synoptic conditions. The H of the FPV site and the REF site in the effective datum was 11.6 W·m−1), water-atmosphere temperature difference , and water–air vapor pressure deficit . The correlation between H and some environmental factors  was negative in the FPV site under sunny and cloudy conditions  was very weak on a cloudy day indicating that the LE was not driven by the U. In addition, the correlation between LE and the U × ∆e was higher than that of the U under the same synoptic conditions. Therefore, the driving force of LE is dominated by the U × ∆e. In particular, the explanation of U × ∆e to the LE is close 80% under cloudy conditions.The relationship between the H, LE, and environmental factors in the FPV site under different synoptic conditions was shown in Fig. ons Fig. a,b,e,f. ons Fig. c,d,g,h f2 = 0.012). The driving force of U × ∆T can only explain about 1% of the change in H. But the explanation of driving force U × ∆T was 23% (R2 = 0.23) for H in the FPV site under cloudy conditions. Because the shadowing effect of PV arrays affects the wind speed and the warming effect of arrays induces the air temperature. Therefore, the explanation of driving force U × ∆T was significantly improved for H after the deployment of PV arrays on the lake under the same weather conditions. The correlation between LE and U was negative, which was opposite to the result in the FPV site under the same weather conditions. In addition, the correlation between LE and U × ∆e was positive in two site under a cloudy condition. But the correlation of LE and U was different in the two sites. Therefore, the change of LE was not determined by the U and the multiple driving forces (U × ∆e) were functionary for LE. The H was driven by the U × ∆T and ∆T in the FPV site under sunny and cloudy conditions. And this correlation was weak in the REF site under cloudy conditions. Those results were contrary to the Nordbo et al.17 study that the H on a natural lake can be explained by the U × ∆T. The explanation of U × ∆T for the H was improved after deploying the PV arrays on the natural lake. The correlation between H and U × ∆T from the FPV site to the REF site was decreased gradually. Meanwhile, the correlation between LE and U × ∆e from the FPV site to the REF site presented the same change of H and some driving force, such as U × ∆T. The change in correlation between energy flux and driving forces indicated the impact of PV arrays on the local environment. The major driving force of dominating the LE was U × ∆e in the two sites under sunny and cloudy conditions. This result is consistent with the study of Du et al.26 on Erhai Lake in China, and this relationship is also found in lakes in Germany and France27. Because the PV arrays block off the airflow which leads to the reduction of the resistance of air. Meanwhile, the ∆e is increased with the airflow decrease. Therefore, the explanation of U × ∆e for LE in the FPV site was greater than that of the REF site.The relationship between the energy flux (H & LE) and its driving force in the REF site on a cloudy day was shown in Fig. 2 is from 0.15 to 0.45 and in Fig. 2 is 0.012 to 0.24. The correlation value is unsufficient. These meteorological factors for the driving force of energy flux were selected according to the Nordbo et al. results on natural lake17. The R2 is lower due to the underlying surface of the lake being changed by installing solar panels. Of course, our results indicated that the driving force of energy flux is affected by the deployment of solar panels on natural lakes. Therefore, the relationship between the driving force of energy flux and meteorological factors are explored by the correlation coefficient matrix to illustrate the effect of the deployment of solar panels on natural lakes on energy exchange.In general, in Fig. The driving force of energy flux in the FPV site is different from the natural lake. The correlation coefficient matrix between energy flux and environmental factors in the FPV site under different synoptic conditions is shown in Fig. −2, 209.3 W·m−2, respectively. In addition, the average ULR in the FPV site is 1.73 W·m−2 higher than the reference site.The radiation components were significantly different in the two sites under various synoptic conditions. The DSR and Rn were presented with one peak on a sunny day. But the smooth characteristic curve in DSR and Rn is interrupted on other synoptic conditions. The daily average DSR and Rn in the two sites were 279.1 W·m−2 (FPV site), 19.2 W·m−2 (REF site), respectively. The LE was 53.2 W·m−2 and 75.2 W·m−2 on counterpart. The water body generally absorbs heat from the air (daily average ∆Q was 16.6 W·m−2) in the FPV site on a sunny day.The H change was fluctuant in the two sites under various synoptic conditions due to the impact of DSR on T_panel. The LE was relatively stable in the two sites under different synoptic conditions. The daily average (cloudy day and rainy day) H in the two sites was 39.5 W·mThe driving force of H in the FPV site is governed by the T_panel under sunny and cloudy conditions. The main driving force of LE is U × ∆e on sunny and cloudy condition for the FPV site.The deployment of PV on the lake is forming a new type of underlying surface. The analysis of radiation, energy flux, and its driving force in the two sites to understand the interaction of air-lake boundary layer. In addition, the study of the difference in radiation under various synoptic conditions may improve the accuracy of solar forecasts on a short-term scale. The study analyzed the difference in radiation, energy flux, and driving force under different synoptic conditions by comparing the FPV site and the REF site. The following conclusions are derived from the situ observations and investigation:The analysis of radiation, energy flux, and its driving forces under different synoptic conditions by comparing the two sites. But there are limits in this paper. The results were obtained by the selection of three days due to the observational data limitation. The data details in the study are shown in Supplementary Information.