地球科学最新文献

{"title":"Changes in the thermal stress across Europe between 1940-2023.","authors":"Luminiţa Mărmureanu, Bogdan Antonescu, Dragoş Ene, Simona Andrei, Raluca Turcu","doi":"10.1007/s00484-025-03043-x","DOIUrl":"https://doi.org/10.1007/s00484-025-03043-x","url":null,"abstract":"<p><p>Long-term changes (1940-2023) in thermal stress and its drivers in Europe were investigated based on the Universal Thermal Climate Index (UTCI) extracted from the ERA5-HEAT reanalysis. Furthermore, a vulnerability index was introduced to assess the impact of thermal stress. The results reveal a rapid continental shift in thermal stress toward milder conditions. Although cold stress is declining fastest in northern regions (more than 4 hours·decade[Formula: see text]), heat stress is intensifying across southern Europe (more than 3 hours·decade[Formula: see text]). Such changes are driven by an increase in 2 m air temperature (between 0.2 up to 0.6[Formula: see text]C·decade[Formula: see text]) and mean radiant temperature, particularly over northern and central Europe, and by changes also in relative humidity and wind speed. One of the key findings of this study is the decline in wind speed in specific areas of central and eastern Europe, leading to an increase in UTCI. Monthly analyzes show that winters warm the fastest (e.g., January cold stress decreases by 1.93%·decade[Formula: see text]), while summer heat stress peaks in July (0.27%·decade[Formula: see text]). In particular, the late spring months (e.g., May) also exhibit a positive trend, contributing to an extended warm season in Europe. Although European UTCI trends generally show a migration of thermal stress categories toward no to moderate-stress, city-level findings highlight more pronounced effects in continental cities such as Milan, Italy, and less pronounced effects in coastal areas like Madrid, Spain compared to cities of similar latitude. Furthermore, Heat Vulnerability Index reveals that highest vulnerability in southern and eastern Europe. These findings support policymakers in developing science-based measures to mitigate thermal risks, addressing both climatic and socioeconomic vulnerabilities in an era of rapid urbanization and climate change.</p>","PeriodicalId":588,"journal":{"name":"International Journal of Biometeorology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145237711","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long‐Term Prediction Model for Erosion‐Deposition Topographic Evolution in the Sanmenxia‐To‐Xiaolangdi Reach of the Yellow River Based on Deep Learning","authors":"Xiaojuan Sun, Haojie Jin, Mingyu Gao, Shengde Yu, Jiayi Man, Qiting Zuo, Wei Zhang","doi":"10.1029/2025wr040669","DOIUrl":"https://doi.org/10.1029/2025wr040669","url":null,"abstract":"Reservoirs are essential for global water management and energy regulation, but sedimentation threatens their longevity. This study investigates a 130 km section of the Yellow River between the Sanmenxia and Xiaolangdi dams, using deep learning to predict long‐term erosion and deposition patterns. From 2009 to 2023, we gathered water depth data from 56 sites (840 measurements) with unmanned survey boats and drone‐based LiDAR (Light Detection and Ranging), alongside flow and sediment records. After preprocessing, we evaluated three machine learning models: Convolutional Network for Multimodal Time Series (CNN‐MTS), Convolutional Transformer for Multimodal Time Series (CNN‐Transformer‐MTS), and Convolutional Bi‐LSTM for Multimodal Time Series (CNN‐BiLSTM‐MTS). The CNN‐BiLSTM‐MTS model excelled, achieving a mean absolute error (MAE) of 17.84 m, a coefficient of determination (<jats:italic>R</jats:italic><jats:sup>2</jats:sup>) of 0.9916, and reducing errors by up to 26% compared to alternatives. Key drivers of sediment dynamics included sediment load, maximum sediment concentration, and maximum flow. Data from 2009 to 2023 showed elevation shifts from −0.21 m near the dam to +1.158 m at the reservoir's tail. Predictions for 2024 to 2050 suggest varied riverbed changes, with the Guxian Reservoir's operation in 2036 expanding elevation ranges from −0.625 to 0.875 m. These findings highlight deep learning's potential for efficient sediment management in reservoirs and offer insights for sustainable hydraulic engineering. However, uncertainties persist in scaling the model, improving data resolution, and coordinating across regions.","PeriodicalId":23799,"journal":{"name":"Water Resources Research","volume":"5 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145235138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cloud Feedback Uncertainty in the Equatorial Pacific Across CMIP6 Models","authors":"Peter G. Hill, Declan L. Finney, Mark D. Zelinka","doi":"10.1029/2025gl117183","DOIUrl":"https://doi.org/10.1029/2025gl117183","url":null,"abstract":"Cloud feedback is the largest uncertainty in estimating Equilibrium Climate Sensitivity. In this study we focus on the equatorial Pacific, where CMIP6 model cloud feedback spread is notably large. Cloud radiative effects in this region are relevant for the global climate. Our findings show that models predict a consistent shift towards the ascent regime in response to El Nino‐like sea surface warming. Models diverge in terms of the radiative impact due to differences in cloud characteristics in ascent and subsidence regimes. Using the observed relationship between circulation regime and cloud radiative effect, we find a reduction in the regional mean cloud feedback estimate from 0.77 to 0.22 , though this does not substantially lessen the model spread in total feedback. Pathways to reduce this spread include: improving confidence in the regional ocean warming pattern, and using observations and models to understand cloud type and circulation interactions.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"18 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the First Impressions of the Wide-Swath Altimetry SWOT Mission Over the Ganga River, India","authors":"Pankaj R. Dhote, Ankit Agarwal, Adrien Paris, Gaurish Singhal, Praveen K. Thakur, Hind Oubanas, Daniel M. Moreira, Laetitia Gal, Vaibhav Garg, Pramod Kumar, Raghavendra P. Singh, Stephane Calmant","doi":"10.1029/2025gl115402","DOIUrl":"https://doi.org/10.1029/2025gl115402","url":null,"abstract":"The Surface Water and Ocean Topography (SWOT) mission offers novel global observations of river hydrodynamics, yet its performance across varied river morphologies remains understudied. We evaluate SWOT node and raster products over a ∼210 km stretch of the Ganga River, India, during the fast-sampling phase, using GNSS-based continuous measurements, two in situ stations, and four altimetry virtual stations. Node products show slightly better water surface elevation (WSE) accuracy than raster products, with RMSEs of 0.19 m (GNSS), 0.09 m (in situ station, Varanasi), and 0.88 m (virtual stations), though quality filters reduce temporal resolution. Raster data, however, captures 2D WSE variability, enhancing spatial sampling in wide river cross-sections. SWOT-derived water surface slopes (WSS) yield mixed results across SWORD reaches (RMSE: 2.54 cm/km). Strong backscatter from main river channel waters (mean +13.34 dB) aids width retrieval. Our analysis highlights SWOT's potential for river hydrodynamic applications while underscoring the need of evaluation in complex riverine environments.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"103 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emergent Constraint on CMIP6 Model Projections of Winter Ice‐Free Periods in the Barents–Kara Sea","authors":"Yuzhuo Peng, Anmin Duan, Zili Shen, Jilin Wei, Shutao Cao","doi":"10.1029/2025gl117660","DOIUrl":"https://doi.org/10.1029/2025gl117660","url":null,"abstract":"Severe winter ice loss in the Barents–Kara Sea (BKS) affects the local environment and climate in other regions. To reduce sea ice projection uncertainties and reliably identify future ice‐free periods, we apply a time‐varying emergent constraint method to model simulations from the Coupled Model Intercomparison Project Phase 6 (CMIP6). For SSP5‐8.5, the constrained ice‐free date is the multi‐model ensemble mean (MMEM) estimate of 2071–2075 with a 90% confidence range (equivalent to IPCC's “very likely range”) of [2047, 2100+], while it shifts to 2086–2090 with the very likely range of [2054, 2100+] for SSP3‐7.0. For SSP2‐4.5 and SSP1‐2.6, the very likely range for the ice‐free dates are [2080, 2100+] and [2095, 2100+], while ice remains in the optimal constrained MMEM sea ice concentration. Relative to the unconstrained results, the optimal constrained maximum probability of an ice‐free BKS increases notably under SSP5‐8.5 and SSP3‐7.0, but decreases under SSP1‐2.6 and SSP2‐4.5.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"53 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of street tree parameters on PM_2.5 diffusion in street canyons? Evidence from a parametric study.","authors":"Ruofan Xu, Jingru Yang, Dan Wang, Xiaoshuang Wang, Yang Xiang, Prashant Kumar, Xiaoping Chen","doi":"10.1007/s00484-025-03023-1","DOIUrl":"https://doi.org/10.1007/s00484-025-03023-1","url":null,"abstract":"<p><p>Traffic-related PM_2.5 worsens street air quality and affects pedestrian health, and the benefits of street trees in reducing air pollution within street canyons are still controversial. To clarify the influence of street tree parameters on PM_2.5 dispersion, tree height (TH), tree spacing (TS) and leaf area density (LAD) were selected from three different categories to represent the common characteristics of street tree species. Field measurements were conducted to validate ENVI-met model. We carried out 64 simulation scenarios with different parameters (TH, TS and LAD) and a treeless scenario in idealized street canyons (aspect ratio = 1:1) under oblique wind direction. The results showed that the 3D surface plots can effectively display the spatial distribution of PM_2.5 within street canyons. PM_2.5 concentration increased after planting trees; the leeward side showed higher concentrations than windward side, and the downstream showed higher concentration than upstream area. TH and LAD significantly influenced PM_2.5 concentration, while TS had less influence, and their effects differed in spatial position. PM_2.5 reduction efficiency (RE) varied with different street tree parameters on the windward side and leeward sides. Sky view factor (SVF) was significantly negatively correlated with PM_2.5 concentration, while green coverage ratio (GCR) and green plot ratio (GPR) were inversely correlated. TH = 6 m, TS = 6 m and LAD = 1.0 m² m^-3 could be a suitable parameter combination for street tree planting or pruning. These results could provide practical suggestions for urban planning and landscape design to improve street air quality and promote sustainable urban development.</p>","PeriodicalId":588,"journal":{"name":"International Journal of Biometeorology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phytoplankton enhances the flocculation of suspended particulate matter in a turbid estuary","authors":"Luz Amadei Martínez, Koen Sabbe, Michael Fettweis, Xavier Desmit, Yves Israel, Wout Bakker, Renaat Dasseville, Sofie D'hondt, Ilse Daveloose, Tine Verstraete, Peter Chaerle, Natacha Brion, Tom Maris, Wim Vyverman","doi":"10.1002/lno.70216","DOIUrl":"https://doi.org/10.1002/lno.70216","url":null,"abstract":"Over the past decades, improvements in water quality—particularly increased oxygen and reduced nitrogen concentrations—have led to changes in phytoplankton biomass and community composition in the Schelde estuary, a macrotidal estuary in Belgium/SW Netherlands. We argue that these changes have affected SPM dynamics by modifying floc stability and size. Seasonal and spatial variability in SPM flocculation dynamics were examined using water samples collected monthly from December 2021 to December 2022 at five stations in the freshwater and brackish tidal reaches of the estuary. In a custom‐built flocculation chamber, these samples were first subjected to a high turbulent shear rate (45 s<jats:sup>−1</jats:sup>) to break the flocs, followed by a lower shear rate (20 s<jats:sup>−1</jats:sup>) that promoted aggregation for 120 min. Floc size distribution changes were analyzed to determine key flocculation parameters, in particular, equilibrium floc size (<jats:italic>D</jats:italic><jats:sub><jats:italic>e</jats:italic></jats:sub>), and flocculation speed (<jats:italic>V</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>). Using generalized additive models, we assessed the influence of seasonal, spatial, environmental, and biotic factors on <jats:italic>D</jats:italic><jats:sub><jats:italic>e</jats:italic></jats:sub> and <jats:italic>V</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>. Unlike in the brackish stations, the freshwater stations displayed clear seasonal patterns in flocculation dynamics, with <jats:italic>D</jats:italic><jats:sub><jats:italic>e</jats:italic></jats:sub> and <jats:italic>V</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub> increasing in spring and summer. The strong positive correlations between <jats:italic>D</jats:italic><jats:sub><jats:italic>e</jats:italic></jats:sub>, <jats:italic>V</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub>, and Chl <jats:italic>a</jats:italic>, as well as between <jats:italic>V</jats:italic><jats:sub><jats:italic>f</jats:italic></jats:sub> and phytoplankton‐derived particulate organic carbon, suggest that phytoplankton plays a key role in the flocculation process. Transparent exopolymer particles (TEP), which because of their sticky properties can promote particle coagulation, were only weakly correlated with enhanced flocculation, suggesting that TEP properties may be affected by factors such as its specific composition, age, and remineralization.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"107 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145234989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of Vegetation Greening on Summer Mean and Extreme Land Surface Temperatures in Eastern China","authors":"Guoshuai Liu, Weiguang Wang, Zefeng Chen","doi":"10.1029/2025gl118453","DOIUrl":"https://doi.org/10.1029/2025gl118453","url":null,"abstract":"Vegetation greening in China is known to cool the land surface by altering the energy budget through biophysical processes. However, its mitigation effects on extreme temperatures and the underlying mechanisms remain poorly understood. Here, we use coupled land‐atmosphere model simulations to quantitatively assess the effects of vegetation greening on summer mean and extreme land surface temperatures in Eastern China over the 2003–2018 period. We show that the modeled cooling effect on summer mean land surface temperature is more pronounced in arid Northeastern China than in humid Southeastern China, consistent with satellite‐derived temperature responses. In contrast, for extreme hot temperatures, the spatial pattern of the cooling effect reverses, largely because high temperatures accompanied by strong radiation can alleviate energy constraints on evaporative cooling in Southeastern China. These findings underscore the potential role of vegetation greening in mitigating extreme hot extremes, with important implications for local land‐based mitigation and adaptation strategies.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"31 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Delayed Pantropical Carbon Sink Recovery Due To Asynchronous Post-El Niño Photosynthesis and Respiration Trajectories","authors":"Mousong Wu, Marko Scholze, Jing M. Chen, Yann Kerr, Michael Vossbeck, Nemesio Rodriguez-Fernandez, Thomas Kaminski","doi":"10.1029/2025gl116236","DOIUrl":"https://doi.org/10.1029/2025gl116236","url":null,"abstract":"Occurring in 2015/16, the strong El Niño has been shown to significantly influence the pantropical carbon fluxes with multiple lines of evidence. However, a comprehensive understanding on the regional and vegetation-specific net ecosystem productivity (NEP) in response to this El Niño event and its recovery trajectories remain unclear. We revisited the controlling factors in the recovery of pantropical NEP from the 2015/16 El Niño until 2020 using a data assimilation framework. We estimated the pantropical net carbon emissions of 0.91 Pg C/yr in 2015 and the mean fraction of recovered area was 0.77 ± 0.07 during 2016–2020. Specifically, we found that temperature and radiation played dominant roles in controlling the recovery of forests' NEP via reducing photosynthesis. Furthermore, we revealed the compound climatic controls on enhanced ecosystem respiration offset NEP recovery over non-forests. These results suggest that the divergence in carbon fluxes regulates the pantropical ecosystem net carbon uptake recovery.","PeriodicalId":12523,"journal":{"name":"Geophysical Research Letters","volume":"75 1","pages":""},"PeriodicalIF":5.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145229377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Direct Thermal Heating on Cracking in Uniaxially Compressed Specimens","authors":"V. A. Zeigarnik,&nbsp;V. A. Novikov,&nbsp;V. N. Klyuchkin,&nbsp;V. I. Okunev","doi":"10.1134/S1069351325700491","DOIUrl":"10.1134/S1069351325700491","url":null,"abstract":"<p><b>Abstract</b>—A number of published papers have suggested that the influence of electromagnetic action on the seismic regime in natural conditions or on crack formation in laboratory experiments can be explained by the role of Joule heating when an electric current passes through fluid-saturated rocks. Heating of the fluid in the pore space can lead to an increase in fluid pressure in pores and cracks, which in turn can trigger additional cracking of the solid skeleton and decrease in rock strength. In this paper, the results of direct heating of artificial sandstone samples under uniaxial compression conditions are presented in order to identify the role of the thermal factor in rock fracture. The samples were taken from the same batch as previously studied in experiments on the effect of passing an electric current through a sample on the acoustic emission (AE) characteristics and on its failure process. In the presented experiments, the heat flow was supplied to the opposite side faces of the sample using Peltier elements, which are reverse thermoelectric converters. The heat flow density on the sample surface reached almost 10⁴ W/m²; the local temperature of the outer surface of the sample near the heating element increased during the heating process by 10–15°C depending on the duration of the switched-on current. Experiments have shown that even with such significant heat flows, the effect of heating is only evident for loads close to fracturing (<i>Kp</i> ≥ 0.95–0.97). The effect of heating was that the process of crack formation in the sample intensified and the sample itself gradually passed into a overcritical state, eventually failing. At lower loads, direct heating of the sample does not have a noticeable effect on the crack formation process.</p>","PeriodicalId":602,"journal":{"name":"Izvestiya, Physics of the Solid Earth","volume":"61 4","pages":"642 - 649"},"PeriodicalIF":1.0,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145230389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}