Journal of Geophysical Research-Oceans最新文献

{"title":"Microbial and Metazoan Activity in Monterey Bay, CA Recorded in Nitrogen Isotope Ratios of Sinking and Suspended Particles","authors":"S. C. Doherty,&nbsp;C. A. Choy,&nbsp;N. L. Paul,&nbsp;H. G. Close","doi":"10.1029/2025JC022372","DOIUrl":"https://doi.org/10.1029/2025JC022372","url":null,"abstract":"<p>Particulate organic matter supports pelagic food webs, and the activity of these food webs attenuates the flux of carbon into the ocean interior. Understanding the extent to which microbial and metazoan heterotrophs influence particle dynamics is essential to describing the biological carbon pump and nutrient delivery to deep ecosystems. We present results of bulk and compound-specific nitrogen stable isotope analyses and a Bayesian mixing model of zooplankton fecal pellets (FP), phytoplankton, and microbial detritus end-members on size-fractionated particulate organic matter from 10 depths in the upper 500 m of Monterey Bay, CA. Our results suggest three distinct zones of plankton-particle interactions in Monterey Bay: primary production and grazing from 0 to 60 m, intense microbial reworking from 60 to 200 m, and inclusion into metazoan food webs below 200 m. Zooplankton FP signatures were found in a &lt;20 μm particle size fraction, both at the approximate depth to which zooplankton migrate at night (∼25–60 m) and in the mesopelagic at the approximate depth to which zooplankton migrate during the day (∼200 m). This finding indicates that fecal pellets were rapidly disaggregated at the depth at which they were produced, which has implications for estimates of zooplankton FP contribution to carbon export and modeling efforts. In some water columns, much of zooplankton FP production may be disaggregated and entrained in the epipelagic zone, above the export depth.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022372","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biologically Mediated Carbon Cycling and Budget in the Yangtze River Estuary and East China Sea","authors":"Jiaxin Chen,&nbsp;Yu Wang,&nbsp;Yuxing Hu,&nbsp;Enquan Zhang,&nbsp;Yunxuan Li,&nbsp;Peihao Liu,&nbsp;Lu Liu,&nbsp;Lilin Wu,&nbsp;Yu Cong,&nbsp;Qiang Zheng","doi":"10.1029/2025JC022835","DOIUrl":"https://doi.org/10.1029/2025JC022835","url":null,"abstract":"<p>The East China Sea (ECS), receiving substantial terrestrial inputs from the Yangtze River, serves as an important carbon sink strongly influenced by biological processes. Although carbon fixation and <i>p</i>CO₂ dynamics have been extensively studied, the biological mechanisms governing organic carbon partitioning, sequestration and their environmental drivers remain unclear. This study integrates spatiotemporal field surveys and incubation experiments to investigate biologically mediated carbon cycling across the Yangtze River Estuary and ECS continuum. Field data highlight that salinity and nutrient-driven biological activity collectively regulate dissolved organic carbon (DOC) concentration and properties. Incubation experiments further revealed how these factors shape bioavailable organic carbon (BOC) and microbial metabolism. Spatially, BOC exhibits a bimodal distribution along salinity gradients, with terrestrial-derived BOC peak in turbid low-salinity zones accelerating mineralization and CO₂ efflux, while plankton-derived BOC maxima in nutrient-rich mid-high salinity regions enhance carbon turnover rate through autotrophic-heterotrophic metabolic coupling, sustaining seasonal DOC accumulation. The ECS exhibited enhanced biological carbon sequestration (including the biological and microbial carbon pump) efficiency compared to oligotrophic oceans, jointly sequestering 8.17 ± 3.19 Tg C a⁻¹, equivalent to 40% of the annual net air-sea CO₂ influx. Moreover, the observed temperature dependence of microbial carbon pump efficiency suggests that ongoing climate change may shift microbial carbon partitioning patterns in marginal seas. This study advances our understanding of carbon transformation and sequestration mechanisms in marginal seas, highlighting the necessity to incorporate microbial feedbacks to improve coastal carbon-climate projections.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin of the Intraseasonal Current Variability and Its Interannual Modulation at 1,000 m Depth in the Eastern Equatorial Pacific Ocean","authors":"Yusuke Terada,&nbsp;Yukio Masumoto","doi":"10.1029/2025JC022754","DOIUrl":"https://doi.org/10.1029/2025JC022754","url":null,"abstract":"<p>It has been shown that the intraseasonal variability in the eastern Pacific Ocean at the intermediate depth (∼1,000 m) has a large amplitude along the equator. However, our understanding of the origin and detailed characteristics of the Equatorial Deep Intra-seasonal Variability (DEIV) is still limited. In this study, we use observed data near the surface and at 1,000 m depth as well as numerical simulations to evaluate the interannual modulation of the DEIV and its relation to the upper-ocean variability. The observed meridional component of eddy kinetic energy (EKE) at 1,000 m depth depicts large intraseasonal variability in the equatorial eastern Pacific, showing a significant seasonality with its maximum in boreal winter. The meridional EKE in winter also indicates a clear interannual variation of the DEIV. The upper-layer equatorially antisymmetric intraseasonal variability, associated with the tropical instability waves, also shows significant interannual modulation with a high correlation to the meridional EKE at 1,000 m with a 3-month lag. Though temperature and velocity observations above 500 m indicate two types of oscillation with 17- and 30-day periods in the upper layer, numerical experiments reveal that during non-La Niña years, only the 30-day component can generate vertically propagating Yanai waves, which effectively form the DEIV.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022754","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low Salinity, High Ocean Heat Content, and Warm Core Eddy Effects on the Upper Ocean Response During Hurricane Sally (2020): An Analysis of a Hurricane Glider Observations and Coupled Atmosphere-Ocean Model","authors":"Senam Tsei,&nbsp;Stephan Howden,&nbsp;Arne -R. Diercks,&nbsp;Jun A. Zhang,&nbsp;Travis N. Miles,&nbsp;Ebenezer Nyadjro,&nbsp;Kevin M. Martin","doi":"10.1029/2024JC021470","DOIUrl":"https://doi.org/10.1029/2024JC021470","url":null,"abstract":"<p>On 15 September 2020, Hurricane Sally traveled within ∼32 km from the location of Seaglider SG601 of the National Oceanographic and Atmospheric Administration/National Weather Service/National Data Buoy Center (NOAA/NWS/NDBC) in the northern Gulf of Mexico (GoM). Data from SG601 were used to examine the changes in the upper 100 m of the ocean under Hurricane Sally winds. In this study, we show a 0.5–1°C cooling of the surface layer, recorded on the day of closest approach (D_CA) of the glider to Hurricane Sally. We also found that freshwater from river discharge created an upper ocean barrier layer, which reduced the cooling of surface (or mixed) layer temperature by 38.6%. The high barrier layer potential energy (BLPE) together with the high buoyancy frequency squared (N²), prior to 15 September, indicated a very stable water column. Further analysis shows the interaction between SG601, Hurricane Sally, and a warm core Loop Current (LC) eddy in the northern GoM. Findings presented in this study also show that ocean models do not effectively simulate river discharge (plume) in the northern GoM.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and Temporal Variability of Upwelling and Downwelling Along the British Columbia Coast During 1993–2021","authors":"Isaak Fain,&nbsp;M. Angelica Peña","doi":"10.1029/2025JC022696","DOIUrl":"https://doi.org/10.1029/2025JC022696","url":null,"abstract":"<p>This study analyzes the spatial and temporal variability in the phenology and magnitude of upwelling and downwelling in the Northern California Current System based on high-resolution wind data and a realistic 29-year hindcast simulation of a regional ocean model. In coastal sectors of approximately 1 degree of latitude, vertical volume transport at a mixed layer depth (MLD) is shown to be highly correlated with local wind forcing, which includes both the divergence of Ekman transport at the coastal boundary and offshore Ekman suction/pumping. The strongest upwelling occurred off the west coast of central Vancouver Island, while the weakest upwelling was observed off the west coast of northern Haida Gwaii. In Queen Charlotte Sound and Hecate Strait, wind stress generated a persistent spatial pattern of alternating strong local upward and downward water movement. Downwelling magnitudes and upwelling onset times were correlated with the winter North Pacific Index (NPI) at several sectors, whereas weaker upwelling and stronger downwelling at northern sectors were associated with the positive phase of the North Pacific Gyre Oscillation (NPGO). The variability in the duration of both seasons was variability of the spring transition. Significant temporal trends were found in the upwelling magnitudes in the southern half of the BC coast. In recent years, the onset of upwelling has occurred earlier, the duration of the summer upwelling season has shown an increasing trend, and downwelling duration has been decreasing.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022696","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Freshwater Sources in the Global Ocean Through Salinity-δ18O Relationships: A Machine Learning Solution to a Water Mass Problem","authors":"Xabier Davila,&nbsp;Elaine L. McDonagh,&nbsp;Fatma Jebri,&nbsp;Geoffrey Gebbie,&nbsp;Michael P. Meredith","doi":"10.1029/2024JC022122","DOIUrl":"https://doi.org/10.1029/2024JC022122","url":null,"abstract":"&lt;p&gt;Changes in the hydrological cycle can affect ocean circulation and ventilation. Freshwater enters the ocean as meteoric water (MW; precipitation, river runoff, and glacial discharge) and sea ice meltwater (SIM). These inputs are traced using seawater salinity and stable oxygen isotopes in seawater, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mn&gt;18&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${delta }^{18}mathrm{O}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. We apply a self-organizing map, a machine learning technique, to water mass properties to estimate the global distribution of the isotopic signature of MW &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mn&gt;18&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mi&gt;W&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({delta }^{18}{mathrm{O}}_{MW}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; by characterizing distinct salinity-&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mn&gt;18&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${delta }^{18}mathrm{O}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; relationships from two comprehensive data sets. The inferred &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mn&gt;18&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;M&lt;/mi&gt;\u0000 &lt;mi&gt;W&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${delta }^{18}{mathrm{O}}_{MW}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is then used in a three-endmember mixing model to provide a globally coherent MW and SIM contributions to the extratropical ocean freshwater budget. Through the use of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mn&gt;18&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC022122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Beaufort Gyre Isopycnal Structure Produces a Steady Mesoscale Eddy Field Modulated by Sea Ice Drag","authors":"Hassan Mason,&nbsp;K. Shafer Smith","doi":"10.1029/2024JC022273","DOIUrl":"https://doi.org/10.1029/2024JC022273","url":null,"abstract":"&lt;p&gt;The Beaufort Gyre (BG) mean state is set by a balance between surface wind stress, sea ice, and subsurface eddy transport. This study addresses the existence and generation of the eddies. We show that underice baroclinic instability of the observed BG mean state produces an eddy field that is both consistent with observations and sufficient to maintain the mean state. We use high-resolution simulations forced by the BG mean state to spin up a steady eddy field. The model includes a representation of sea ice with active rheology but inactive thermodynamics. Each simulation is initialized with different sea ice concentrations that remain constant throughout each integration, thus imparting varying amounts of surface drag. We find that these simulations are characterized by two regimes: a static ice regime with strong surface drag and a motile ice regime with low surface drag. Simulations in the motile ice simulations exhibit high eddy energy with near-surface maximum eddy velocities of about &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;30&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $30,$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; cm s&lt;sup&gt;−1&lt;/sup&gt; and eddy diffusivities of about &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;4000&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $4000,$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; m&lt;sup&gt;2&lt;/sup&gt; s&lt;sup&gt;−1&lt;/sup&gt;. Eddy energy is lower in the static ice regime but nevertheless maintains significant strength at the halocline depth (150 m) with eddy velocity maxima exceeding &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $10,$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; cm s&lt;sup&gt;−1&lt;/sup&gt;. Eddy diffusivity under static ice (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;O&lt;/mi&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1000&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathcal{O}left(1000,right.$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; m&lt;sup&gt;2&lt;/sup&gt; s&lt;sup&gt;−1&lt;/sup&gt;)) peaks just below the surface and decays with depth, which is consistent with the upper end of previous analyses. This work both suggests the presence of locally generated halocline-intensified eddies and provides insight into the future behavior of the BG as we slowly transition to an ice-free Arctic.&lt;","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145146910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrographic Changes and Water Mass Distribution in the Norwegian Sea, 1995–2023","authors":"K. A. Mork,&nbsp;Ø. Skagseth,&nbsp;H. Søiland","doi":"10.1029/2025JC022397","DOIUrl":"https://doi.org/10.1029/2025JC022397","url":null,"abstract":"<p>Intermediate and deep water of the Norwegian Sea comprise overflow water that feeds the deepest limb of the Atlantic Meridional Overturning Circulation. Here, we investigated the variability and sources of intermediate and deep-water masses in the Norwegian Sea from 1995 to 2023, using repeat hydrographic sections and a combination of ship-based measurements and Argo data. Intermediate waters exhibited substantial warming, with rates of approximately 0.1°C decade⁻¹ at ∼1,000 m depth, while deep waters below 2,000 m warmed at 0.05°C decade⁻¹. Salinity variability was prominent at intermediate depths, and the Norwegian Sea Arctic Intermediate Water (NSAIW) layer, originating from the Greenland Sea Arctic Intermediate Water (GSAIW), became progressively thinner and shallower. The most pronounced thinning occurred during the 2000s, when the GSAIW became warmer and with properties more similar to the NSAIW. In the Norwegian Sea a prominent intermediate layer with salinity below 34.90 psu disappeared about 2010 due to increased salinity, but reemerged in the past 2–3 years as a distinct 200 m thick layer above the NSAIW, originated from the southern Greenland Basin. These changes highlight the sensitivity of the Nordic Seas to climate variability with implications for regional and global ocean circulation.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 9","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022397","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145146529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Techno-Societal Framework for Quantifying the Risk of Heavy Rainfall Events Over Ramsar Wetlands","authors":"Shivukumar Rakkasagi,&nbsp;Manish Kumar Goyal,&nbsp;Srinidhi Jha","doi":"10.1029/2025JC022563","DOIUrl":"10.1029/2025JC022563","url":null,"abstract":"<p>Wetlands are often found in depressions or around rivers, lakes, and coastal seas, where they periodically flood. Hence, this study presents a new techno-societal framework for quantifying the risk of heavy rainfall events (HREs) on wetland ecosystems and surrounding communities in India. By integrating advanced technological approaches such as Bayesian analysis, fuzzy logic, and remote sensing with societal considerations, we provide a comprehensive assessment of wetland vulnerability to climate change impacts. An effort has been made to understand the non-stationarity of HREs, inundation patterns of wetlands, impact evaluation, and future precipitation trends (CMIP6). The overall assessment of the extreme precipitation indices indicated that return periods were highest for Thane Creek, followed by Bhoj Wetland. We also assessed the risk index based on the parameters of hazard, vulnerability, and exposure for all wetlands using the fuzzy logic approach. The overall risk index evaluation indicated that Bhoj Wetland, Thane Creek, Point Calimere, Deepor Beel, Sasthamkotta Lake, and Vembannur Wetland are at “very high” risk. The study also investigated inundation patterns of critical “very high” risk wetlands and conducted an impact evaluation for the Bhoj Wetland, highlighting the influence of HREs on infrastructures, human settlements, and ecosystems. Wetlands such as Point Calimere, Vembannur Wetland, Karikili Bird Sanctuary, Vendanthangal, and Vaduvur Bird Sanctuary showed a significantly increasing trend in precipitation for both historical and future SSP2-4.5 scenario. These findings are useful in decision-making for policymakers to adopt the best practices to manage the local wetlands wisely.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 9","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observations of Coastal Ocean-Atmosphere Interactions From Three Tropical Cyclones During the Fall Transition of 2017 in the Mississippi Bight, Northern Gulf of Mexico","authors":"B. Dzwonkowski,&nbsp;S. Fournier,&nbsp;R. Carwithen,&nbsp;G. Lockridge,&nbsp;Z. Liu,&nbsp;J. Coogan,&nbsp;K. Park,&nbsp;U. Nwankwo,&nbsp;D. R. M. Rao","doi":"10.1029/2025JC022564","DOIUrl":"10.1029/2025JC022564","url":null,"abstract":"<p>Overlap between peak hurricane (i.e., strong tropical cyclone) activity and the fall transition represents a period when coastal ocean-hurricane interactions can be highly variable due to rapid changes in seasonal hydrographic conditions. However, understanding of the response of the coastal ocean to tropical cyclone passage is limited due to the difficulty of collecting observations during such extreme events. Here, observations on the shelf were used to investigate coastal ocean-atmosphere interactions during the passage of three tropical cyclones in the northern Gulf of Mexico during the fall of 2017. Tropical depression conditions associated with Hurricanes Harvey and Irma and Hurricane Nate impacted the Mississippi Bight region within a 6-week span (late August–early October) when the fall transition typically begins. Despite large impacts from Harvey and Irma, which pushed the system into a marine cold spell, a rewarming event changed the trajectory of the fall transition, extending the period when the shelf temperature remained favorable for hurricane intensification. In contrast, Nate, the most direct storm hitting the study area, had minimal impacts on shelf conditions, even at sites within the inner core of the storm. All storm responses were linked to moisture disequilibrium and direction of the across-shelf wind where southward offshore (northward onshore) winds generated higher (lower) vertical gradients in humidity. Overall, these events show the impact that even distant hurricanes can have on the fall transition as well as highlight the need for improving the understanding of factors that influence thermodynamic disequilibrium in the coastal zone.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 9","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145111057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}