Journal of Geophysical Research-Oceans最新文献

{"title":"The Daylight Bias: How Solar Tides Skew Satellite Estimates of Coastal Suspended Sediment Concentration","authors":"Mingxiang Pan,&nbsp;Shiyi Cao,&nbsp;Jie Feng,&nbsp;Yunwei Wang,&nbsp;Hangjie Lin,&nbsp;Ya Ping Wang,&nbsp;Qian Yu","doi":"10.1029/2026JC024186","DOIUrl":"https://doi.org/10.1029/2026JC024186","url":null,"abstract":"<p>The long-term mean Suspended Sediment Concentration (SSC) is a critical parameter for characterizing coastal sediment dynamics and associated ecological effects. While satellite optical remote sensing serves as a primary tool for these observations, standard climatological estimates typically rely on averaging data acquired during fixed daylight hours. This approach implicitly assumes that satellite sampling is random and unbiased, an assumption we demonstrate fails in coastal regions dominated by strong solar semidiurnal tides. In such systems, tidal forcing generates pronounced 12 hr (S2) and 6 hr (S4) variability that becomes harmonically synchronized with the satellite's daylight sampling window. This “stroboscopic effect” aliases periodic fluctuations into a systematic “daylight bias” within climatological means derived from arithmetic averaging. To address this, we propose a Solar-Phase Harmonic Fitting method that mathematically decouples the background mean from the S2 and S4 components, given sufficient intraday sampling. Application to Korea Bay reveals that tidal advection across a seaward-decreasing SSC gradient drives strong S2 variability, with satellite daylight sampling phase-locked to low-SSC conditions. Consequently, under the framework of daylight sampling, conventional averaging underestimates the long-term mean SSC by approximately 23.4% in the coatal ocean. Our proposed method mitigates the daylight bias in long-term mean estimations, yielding less biased results than conventional arithmetic averaging, and offers a framework broadly applicable to other satellite-derived oceanographic variables influenced by tidal or solar-driven variability, such as water transparency and chlorophyll-a.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148942206","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":"Impacts of Cross-Shore Winds, Waves, and Sand Ridges on Inner Shelf Circulation","authors":"B. U. Ayhan,&nbsp;M. S. Parlak,&nbsp;J. C. Warner,&nbsp;T. S. Kalra,&nbsp;I. Safak","doi":"10.1029/2025JC023593","DOIUrl":"https://doi.org/10.1029/2025JC023593","url":null,"abstract":"<p>Understanding of circulation on inner continental shelves needs to be advanced to accurately predict the transport and connection between the shelves and nearshore. The circulation over the storm-dominated Fire Island Shelf, New York and a series of in situ shoreface connected sand ridges was investigated through high-resolution field observations, numerical simulations of hydrodynamics, and principal component analyses. The along-shelf subtidal flows were more energetic than the cross-shelf subtidal flows. Alongshore winds were driving the along-shelf subtidal flow and the variability of water levels. The cross-shelf subtidal flows were dominantly onshore near the seabed and offshore near the surface: the processes significant in this two-layer exchange were cross-shore winds which were commonly overlooked in literature, alongshore winds through Coriolis, and bottom friction. The ridges were significant in changing the magnitude and even the direction of the pressure gradients and associated flows. Wave impacts including water level changes, Stokes drift, vortex force, and breaking became significant in the inner shelf and the nearshore during wave-energetic events. Depending on the directions of waves and winds, waves caused to accelerate or decelerate and even reverse the wind-induced flow. In case of more shore-normal waves, the cross-shore Stokes drift became more significant; its interaction with Earth's rotation and flow vorticity generated significant Stokes-Coriolis impacts and vortex force, respectively, in the alongshore. With results applicable to other shelf settings, this study advanced the understanding of spatial and temporal variations of flows along and across inner shelves under varying forcing conditions.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023593","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149145597","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":"Observed Bottom Intensified Diurnal Currents on the Upper Continental Slope North of Svalbard","authors":"Christophe Herbaut,&nbsp;Marie-Noëlle Houssais,&nbsp;François Dupé,&nbsp;Agnieszka Beszczynska-Möller,&nbsp;Hanne Sagen,&nbsp;Hervé Le Goff,&nbsp;Matthieu Labaste,&nbsp;Casimir de Lavergne,&nbsp;François Challet,&nbsp;Gaëlle Herbert,&nbsp;Carole Saout","doi":"10.1029/2025JC023941","DOIUrl":"https://doi.org/10.1029/2025JC023941","url":null,"abstract":"<p>In the Arctic Ocean, dissipation is generally weak except for some hot spots on the continental slope or along the edge of the Yermak Plateau where observations suggest that tidal currents are the main source of dissipation. In this study, we analyze observations collected between September 2017 and November 2019 from a mooring deployed on the sea floor at a depth of 500 m on the upper slope north of Svalbard, as part of the INTAROS project. Thanks to a 2-year long time series of current and hydrographic properties, we report periods of amplification of the cross-slope bottom velocity at the diurnal frequency. The amplification occurs mainly in late fall-early winter and in summer and can be accompanied by diurnal variations of the temperature and salinity, while the diurnal signal vanishes in late winter-early spring. Experiments with Brink’s (2006, https://github.com/KenCTW/BaroclWaves) simplified model suggest that the observed ambient stratification and the bottom topography of the region together create favorable conditions for the resonance of coastal trapped waves generated by the diurnal tides. However, such conditions are not present throughout the year; the combined effects of weakened stratification and strong mean along-slope current in late winter prevent the occurrence of such a resonance. The stratification between 250 and 500 m appears instrumental to bottom intensification of the cross-slope current during specific periods. However, it was not possible to identify signatures of enhanced dissipation associated with such bottom-intensified diurnal currents.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023941","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148943683","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":"Excessive Negative Surface Heat Flux Feedback in CMIP6 Models","authors":"Andrew George,&nbsp;Zhengyu Liu,&nbsp;Tianying Liu,&nbsp;Peng Gu","doi":"10.1029/2026JC024124","DOIUrl":"https://doi.org/10.1029/2026JC024124","url":null,"abstract":"<p>Local surface heat flux feedback plays a critical role in modulating sea surface temperature (SST) variability. Here we estimate local surface heat flux feedbacks using an observational and a reanalysis data set, and outputs from 27 CMIP6 models. We find that CMIP6 models systematically overestimate the magnitude of negative net surface heat flux feedback by 22%–27% globally. This excessive damping mainly arises from overly strong latent heat flux feedback globally, with an additional contribution from stronger shortwave feedback in the tropics. Despite these strong negative feedbacks, SST variability in CMIP6 models does not show clear signs of excessive overdamping, as both SST variance and persistence are broadly consistent with observations. This apparent inconsistency suggests compensating oceanic processes, potentially related to underestimated ocean damping or biases toward overly deep mixed layer depths.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149206183","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":"Annually Resolved 239,240Pu and 237Np Records in a Coral (1947–2007): Transport Timescales and Current Modulation From the Pacific to the South China Sea","authors":"Quandi Liu,&nbsp;Wu Men,&nbsp;Fenfen Wang","doi":"10.1029/2026JC024644","DOIUrl":"https://doi.org/10.1029/2026JC024644","url":null,"abstract":"<p>This study presents the first annually resolved record of ²³⁷Np and ^239+240Pu in a coral core collected off eastern Hainan Island in the South China Sea (SCS), covering 1947–2007. Both the ^239+240Pu activity and ²⁴⁰Pu/²³⁹Pu ratio exhibited an initial increase followed by a gradual decreasing trend. The ^239+240Pu activity reached its peak in 1958, earlier than the 1963 global fallout maximum, indicating predominant close-in fallout contributions from the Pacific Proving Grounds (PPG). The ²⁴⁰Pu/²³⁹Pu ratio peaked in 1955, corresponding to the 1952 Ivy Mike thermonuclear test, implying a transport timescale of ∼2–3 years for Pu isotopes to travel from PPG to the study site via Luzon Strait. Based on this timescale, it can be inferred that radionuclides take roughly 15–30 months to transport from the eastern Luzon Strait to the study site. This study also presents the first reported data for ²³⁷Np in a coral core. In contrast to Pu isotopes, ²³⁷Np activity displayed a distinct bimodal pattern, with the first peak occurring in 1958 and a secondary peak in 1960, while the ²³⁷Np/²³⁹Pu ratio increased steadily until 1996. After 1980, several elevated ²³⁷Np activities were significantly correlated with El Niño-Southern Oscillation (ENSO) events. During El Niño episodes, the bifurcation of the North Equatorial Current (NEC) shifts northward, enhancing Kuroshio intrusion into the SCS and thereby increasing the input of PPG-derived radionuclides. Additionally, the characteristic peak timing of Pu-Np can serve as a novel dating method for SCS coral cores.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823382","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":"The Role of Wave-Induced Stress and Drag Coefficients in Offshore Wind Power Production","authors":"Nícolas de Assis Bose,&nbsp;Leandro Farina,&nbsp;Vanessa de Almeida Dantas,&nbsp;Luciano André Cruz Bezerra,&nbsp;Leonardo de Lima Oliveira,&nbsp;Alessandro Renê Souza do Espírito Santos,&nbsp;Ana Cleide Bezerra Amorim,&nbsp;Samira de Azevedo Santos Emiliavaca,&nbsp;Maria de Fátima Alves de Matos,&nbsp;Raniere Rodrigues Melo de Lima,&nbsp;Bryan Thomas Marcondes Bonatto,&nbsp;Antonio Marcos de Medeiros","doi":"10.1029/2025JC023741","DOIUrl":"https://doi.org/10.1029/2025JC023741","url":null,"abstract":"&lt;p&gt;This study investigates wind-wave interactions on offshore wind energy production by comparing a coupled atmosphere-wave model (WRF-SWAN) with a stand-alone atmospheric model (WRF). Using statistical metrics and LiDAR wind measurements from Porto-Ilha, Brazil, we evaluate the model's ability to capture wind variability and air-sea momentum flux at an offshore wind farm site. The coupled WRF-SWAN outperforms the stand-alone WRF, particularly in representing wind-wave dynamics and sea surface roughness. The BEM is a physically distinct and under-explored air–sea interaction domain, where persistent trade winds coexist with long-period North Atlantic swell, producing a bimodal wind–wave regime. Consistent with established observational and modeling evidence, under low wind speeds and strong swell, wave-induced stress &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;τ&lt;/mi&gt;\u0000 &lt;mtext&gt;wave&lt;/mtext&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({tau }_{text{wave}}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; acts upward, transferring momentum from the ocean surface to the atmosphere and locally enhancing wind speeds. This momentum transfer depends on wind-wave alignment, positive when aligned and negative when opposed. Corroborating established theory and observations, wave growth under moderate to strong winds (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;6&lt;/mn&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mi&gt;W&lt;/mi&gt;\u0000 &lt;mi&gt;s&lt;/mi&gt;\u0000 &lt;mi&gt;p&lt;/mi&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;mn&gt;10&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;&lt;&lt;/mo&gt;\u0000 &lt;mn&gt;20&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $6&lt; Wsp{d}_{10}&lt; 20$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; m &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;s&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{s}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) increases sea surface roughness and drag coefficient &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;C&lt;/mi&gt;\u0000 &lt;mi&gt;D&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left({C}_{D}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, leading to wind speed reductions at hub height. In swell-dominated environments, when the wind follows the swell, a reduction in &lt;span&gt;&lt;/span","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823383","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":"Seasonal to Multi-Year Variability of Upwelling Along Southwest Greenland and the Role of Atmospheric Circulation","authors":"Yan Sun,&nbsp;Robert S. Pickart","doi":"10.1029/2026JC024697","DOIUrl":"https://doi.org/10.1029/2026JC024697","url":null,"abstract":"<p>Upwelling along southwest Greenland plays an important role in modulating shelf-basin exchange and influencing deep convection in the Labrador Sea. Here we investigate its seasonal and interannual variability using the Overturning in the Subpolar North Atlantic Program West Greenland mooring observations and atmospheric reanalysis fields. Over the decade 2014–2024 we identified 142 upwelling events. During this time the number of events increased, primarily due to summer events, whereas the mean duration of events decreased for the first 7 years and then rebounded, largely reflecting winter variability. The latter is consistent with the winter North Atlantic Oscillation (NAO), whereas the relationship between the number of summer events and the summer NAO is counterintuitive. Two distinct atmospheric patterns were identified. Most events are associated with forward Greenland tip jets, whereby low-pressure systems deepen in the vicinity of southeast Greenland resulting in enhanced northwesterly winds along southwest Greenland. In contrast, a large number of the summer events are shown to be related to an alternative atmospheric scenario characterized by a weak, distant low-pressure system located south of Iceland coexisting with a high-pressure system over the Labrador Sea. The tracks of these storms are typical of low-NAO conditions, thus explaining the above-noted counterintuitive relationship. Using a proxy we demonstrate that there was a regime shift in 1990/91 after which this type of summer upwelling became more common. Our results highlight a previously underappreciated role of high-pressure systems in driving upwelling variability and provide new insights into the factors controlling upwelling along southwest Greenland.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823384","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 a Tilted, Dual-Core Anticyclonic Eddy With Asymmetric Dynamics in the Eastern South Pacific","authors":"Kun Zhang,&nbsp;Haibin Song,&nbsp;Peiwen Nian","doi":"10.1029/2025JC023805","DOIUrl":"https://doi.org/10.1029/2025JC023805","url":null,"abstract":"<p>Accurately characterizing the three-dimensional structure of oceanic eddies is essential for understanding how they transport water masses, tracers, and energy. Here we investigate a subsurface anticyclonic eddy observed in the eastern South Pacific using coincident multi-channel seismic reflection data, vessel-mounted Acoustic Doppler Current Profiler (vmADCP), satellite altimetry, and in situ hydrography collected in early 2017. The surface envelope defined by the Mesoscale Eddy Trajectory Atlas version 3.2 delayed-time product (META3.2 DT) was horizontally asymmetric, while the vmADCP sections revealed flank-dependent velocity structure and vertically displaced opposite-sign cross-track velocity extrema within a dual-core subsurface structure. Current speeds differed by 16%–27% between the sampled flanks, and the velocity structure showed apparent cross-sectional tilts of 0.12°–0.27°. The upper and lower cores had distinct water-mass signatures resembling Equatorial Subsurface Water (ESSW) and Antarctic Intermediate Water (AAIW), respectively. High-resolution seismic sections further revealed steep, edge-confined reflector bands, interpreted as finescale thermohaline structures or filaments within the eddy margin. The estimated turbulent kinetic energy dissipation rate was approximately one to two orders of magnitude higher in the sampled peripheral regions than in the core, whereas the dissipation maxima did not coincide with the strongest smoothed-field Rossby-number proxy or background shear. These observations show a relatively coherent, hydrographically differentiated dual-core interior surrounded by a finite-width, mixing-prone margin and demonstrate the value of seismic oceanography for resolving subsurface eddy structure and boundary mixing.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823238","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":"Phytoplankton Distribution Across an Anticyclonic Eddy in the Gulf of Mexico","authors":"U. Mirabal,&nbsp;L. Linacre,&nbsp;A. González-Silvera,&nbsp;R. Durazo,&nbsp;E. Pallàs-Sanz,&nbsp;V. F. Camacho-Ibar,&nbsp;M. Latasa,&nbsp;A. Gutiérrez-Rodríguez","doi":"10.1029/2026JC024343","DOIUrl":"https://doi.org/10.1029/2026JC024343","url":null,"abstract":"<p>In the Gulf of Mexico, the Loop Current Eddies (LCEs) are highly dynamic mesoscale structures that significantly influence the physicochemical characteristics of the water column. These anticyclonic eddies modify environmental factors such as solar light penetration and nutrient availability, thereby affecting the growth, structure, and distribution of the phytoplankton community. This study was conducted in the oceanic region of the Gulf of Mexico to characterize the chemotaxonomic composition and size classes of phytoplankton across a young LCE. The analysis employed high-performance liquid chromatography along with the CHEMTAX algorithm and complementary phytoplankton light-absorption coefficients. These approaches revealed significant physiological adaptations in the phytoplankton assemblage related to environmental gradients within the oligotrophic LCE waters and the ecological preferences of its components. The dominance of pico- and nano-sized groups, such as <i>Prochlorococcus</i> and haptophytes (responsible for about 70% of total chlorophyll-<i>a</i>), highlighted the competitive advantage of these groups over micro-sized cells (e.g., diatoms) in the warm, nutrient-poor waters of the anticyclonic eddy. Furthermore, the vertical distribution of phytoplankton groups across different layers of the euphotic zone (from the surface to 0.1% surface irradiance) demonstrated the high level of ecological specialization of phototrophic cells, reflected in their diverse physiological and functional traits suited to thriving in this oligotrophic ecosystem. These findings offer high-resolution observations that help improve parameterizations of phytoplankton adaptation processes in ecological models driven by environmental variability within mesoscale-dominated ecosystems.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823249","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":"Persistent Warming and Reduced Freshening of the Abyssal Southern Ocean","authors":"K. L. Gunn,&nbsp;S. R. Rintoul,&nbsp;M. H. England","doi":"10.1029/2025JC023688","DOIUrl":"https://doi.org/10.1029/2025JC023688","url":null,"abstract":"&lt;p&gt;Antarctic Bottom Water has thinned, warmed, freshened, and spread more slowly into the global ocean since 1970. Yet, the physical drivers of these changes and their broader implications remain incompletely understood. Here we combine up-to-date observations (1985–2024) with ocean model simulations extending to 2050 to quantify ongoing and projected abyssal ocean changes. Between 1985 and 2024 and below 3,000 m depth, isopycnals descended at a rate of −95 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 5 m &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mtext&gt;decade&lt;/mtext&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{decade}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. The water that previously occupied these depths has been replaced by warmer overlying layers resulting in warming of 0.02 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.02 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;°&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${}^{circ}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;C &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mtext&gt;decade&lt;/mtext&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{decade}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;. Freshening of −0.002 &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $pm $&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; 0.003 g &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mtext&gt;kg&lt;/mtext&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{kg}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msup&gt;\u0000 &lt;mtext&gt;decade&lt;/mtext&gt;\u0000 &lt;mrow&gt;\u0000 ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023688","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148823239","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}