Journal of Geophysical Research-Oceans最新文献

{"title":"Phase-Locked Internal-Wave Triads Observed in the Izu-Ogasawara Ridge: Implications for Interplay Between Tides and Winds","authors":"Takashi Ijichi,&nbsp;Ryuichiro Inoue,&nbsp;Yasuo Furushima","doi":"10.1029/2025JC022501","DOIUrl":"https://doi.org/10.1029/2025JC022501","url":null,"abstract":"<p>The Ogasawara subregion of the Izu-Ogasawara-Mariana arc system in the western North Pacific is recognized as one of the most notable hotspots for thermocline turbulent mixing. Although parametric subharmonic instability (PSI) is generally considered a primary driver of enhanced turbulence by facilitating energy transfer from low-mode semidiurnal internal tides to high-mode near-inertial waves (NIWs), recent observations suggest that NIWs remotely induced by winds also contribute to significant seasonal variations in thermocline turbulence in this region. Here, 3-day velocity and density yo-yo measurements, conducted near the PSI critical latitude of 28.8°N opportunistically after several storm passages, reveal the coexistence of PSI-induced high-mode NIWs and wind-induced low-mode NIWs. Two distinct pairs of upward- and downward-propagating NIWs are identified, each forming a phase-locked triad with locally generated upward-propagating semidiurnal internal tides. In a mid-depth layer, a pair of high-mode upward- and downward-propagating NIWs forms a scale-separated PSI triad with the internal tides, whereas in an overlying layer, a pair of low-mode downward-propagating NIWs and intermediate-mode upward-propagating NIWs forms a distinct non-scale-separated triad. Consequently, turbulent dissipation is enhanced at the boundary between these distinct near-inertial velocity layers. These findings are not inconsistent with the view that wind-induced low-mode NIWs interact with internal tides, promoting the growth of intermediate-mode NIWs and eventually contributing to the enhanced thermocline turbulence, thus suggesting an overlooked pathway to turbulence in the ocean interior.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022501","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323549","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":"Longshore Sediment Transport and Morphological Changes Under Climate Change—A Comparison Between CMIP5- and CMIP6-Derived Forcings and the Use of Wave Climate Bias Correction","authors":"G. Vieira da Silva,&nbsp;D. Strauss,&nbsp;T. Murray,&nbsp;F. Alvarez,&nbsp;M. Hemer,&nbsp;A. Meucci,&nbsp;O. Repina","doi":"10.1029/2024JC022212","DOIUrl":"https://doi.org/10.1029/2024JC022212","url":null,"abstract":"<p>Changes in wave climate can impact coastal zones by altering the sediment supplied to coastal compartments via longshore sediment transport (LST). Estimating these changes is challenging, and biases and uncertainty in wave climate projections contribute to uncertainty in LST and morphological change projections. This paper compares wave climate, LST projections, and morphological changes derived from two iterations of the Coupled Model Intercomparison Project (CMIP), and the implications of applying wave climate bias correction in these projections for the late 21st century under high emission scenarios. LST and morphological changes were simulated in a process-based model calibrated with data from a sand bypassing system. Bias correction improved representation of wave climate, including extremes, and reduced variance between climate models. Although bias correction did not change projected mean LST, it reduced the spread of model ensembles by 20% and 10% for CMIP5 and CMIP6, respectively. Both CMIP5 and CMIP6 suggest a future reduction of LST in the study area. However, CMIP6-derived projections show: (a) 50% less variance in wave forcing; (b) greater consistency between ensemble members; and (c) double the reduction in LST. This reduction is attributed to changes in the frequency, intensity and direction of modal and extreme waves. Morphological changes suggest steepening of the beach profiles in line with the historical record. This contribution highlights the value of a bias-corrected model ensemble and improvements in CMIP iterations in providing coherent projections of future wave climate change and its impacts on regional coastal processes.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC022212","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331988","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":"On the Ambiguity of Oceanic Eddy Polarity","authors":"Ge Chen,&nbsp;Xiaoyan Chen","doi":"10.1029/2024JC022239","DOIUrl":"https://doi.org/10.1029/2024JC022239","url":null,"abstract":"<p>Polarity is a fundamental feature of oceanic eddies, which defines many aspects of its hydrodynamics and thermodynamics. Polarity ambiguity is a challenging and sometimes puzzling issue for the classification of eddies and analysis of their dynamics. Here, we propose a new methodology combining drifter-measured currents and temperatures to evaluate the validity of altimeter-derived eddy polarity. Different from previous schemes based purely on assessing oceanic temperature ambiguity of eddies from either satellite or Argo observations, our approach integrates the concurrent vector flow and surface temperature measured by drifters riding on altimeter-tracked eddies. The idea is to examine the consistency between the rotation of drifter trajectory and the spinning of eddy motion on the assumption that the looping and circulating directions are identical for a normal eddy and otherwise for an “ambiguous” or “abnormal” one. For a special class of radial drifter trajectory with respect to the eddy centroid, the temperature trend along its path is used to judge its polarity, that is, warmer toward the core for a normal anticyclonic eddy and colder for cyclonic. Our results reveal that many eddies previously classified as “abnormal” are in fact dynamically or thermally ambiguous due to distortions in their upper-layer structures rather than being genuinely misclassified by altimeter. After excluding such ambiguous cases, only ∼3% of eddies show polarity inconsistency in both aspects. These findings suggest that altimeter-derived eddy polarity is highly reliable, and that combining a multi-parameter, Lagrangian-informed approach offers more accurate interpretations of eddy structures by distinguishing intrinsic anomalies from superficial distortions.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC022239","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144323647","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 and Model-Simulated Dramatic Bottom Temperature Variations During a Weakened Typhoon in the Northern Yellow Sea","authors":"Hang Yu,&nbsp;Nan Wang,&nbsp;Yang Ding,&nbsp;Rui Li,&nbsp;Xianwen Bao,&nbsp;Guandong Gao,&nbsp;Congcong Bi,&nbsp;Lingling Zhou,&nbsp;Zhigang Yao,&nbsp;Kai Wan","doi":"10.1029/2025JC022401","DOIUrl":"https://doi.org/10.1029/2025JC022401","url":null,"abstract":"<p>Observations and a high-resolution ocean model were utilized to investigate the significant bottom temperature response in the north Yellow Sea (NYS) during the weakening of Typhoon Lekima in August 2019. The cyclonic typhoon winds generated prominent cyclonic currents, with eastward (westward) currents along the southern (northern) coast of the NYS. Concurrently, high sea levels occurred along the northern and southern coasts, whereas low sea levels were present in the central NYS. This sea level pattern persisted for a week after the typhoon's dissipation, maintaining the eastward (westward) currents along the southern (northern) coast. The sustained eastward alongshore current transported warm bottom water along the northern coast of the Shandong Peninsula, resulting in a significant bottom temperature increase over 10°C during 4 days. Simultaneously, the westward alongshore current carried cold water from the Yellow Sea Cold Water Mass (YSCWM) along the southern coast of the Liaodong Peninsula, leading to a prominent bottom temperature decrease of 13°C over 6 days. Near-inertial oscillations disturbed the thermocline and created favorable conditions for the bottom warm water advection. Temperature budget analysis further confirmed the dominant role of horizontal temperature advection in these dramatic bottom temperature anomalies. The relatively weaker wind disturbance could still drive strong bottom temperature change in the YSCWM boundary with sharp temperature gradient, which underscores the impact of weaker synoptic weather systems on significant bottom temperature variations in coastal regions with sharp temperature front, which are often ignored compared to much stronger weather events such as typhoons.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331987","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":"Absolute Velocity, Transport and Stability of the Polar Front Downstream of the Southeast Indian Ridge","authors":"Annie Foppert,&nbsp;Stephen R. Rintoul,&nbsp;Helen E. Phillips","doi":"10.1029/2024JC021853","DOIUrl":"https://doi.org/10.1029/2024JC021853","url":null,"abstract":"<p>The fronts of the Antarctic Circumpolar Current (ACC) influence the growth and instability of eddies, eddy-mean flow interaction, and the development of submesoscale processes. We use in situ hydrography and directly measured velocity from a comprehensive shipboard survey of the Polar Front (PF) south of Tasmania to characterize the synoptic mean velocity and transport structure of the PF. A stream-coordinate system, based on dynamic height anomaly (<i>ϕ</i>), is constructed to create an along- and across-stream perspective of the PF that naturally follows the current. We find the surface-intensified along-stream flow carries a full-depth transport of 80.5 Sv over a width of 90 km, with roughly two-thirds carried by the baroclinic flow. The across-stream velocities are largely depth-independent; the mean depth-averaged flow across the PF core is 0.08 m s⁻¹ in the quasi-northward direction, associated with along-isopyncal downwelling and cold water advection. We calculate potential vorticity (PV) to investigate the stability of the PF and find it is susceptible to both baroclinic and barotropic instability. Mean PV is dominated by the thickness PV term <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mfenced>\u0000 <mfrac>\u0000 <mrow>\u0000 <mi>f</mi>\u0000 <msup>\u0000 <mi>N</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <mi>g</mi>\u0000 </mfrac>\u0000 </mfenced>\u0000 </mrow>\u0000 <annotation> $left(frac{f{N}^{2}}{g}right)$</annotation>\u0000 </semantics></math>, that is PV is controlled by changes in stratification. While strong upper-ocean PV gradients indicate a barrier to mixing, weaker PV gradients and relatively elevated mixing lengths at mid-depth (≈2,000–2,500 m depth) suggest a deep steering level where eddies can efficiently mix properties across the PF.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021853","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144332004","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":"High Frequency Radar Observations of East India Coastal Current Eddies","authors":"Pooja Patel,&nbsp;P. N. Vinayachandran,&nbsp;Deepak Subramani","doi":"10.1029/2024JC022154","DOIUrl":"https://doi.org/10.1029/2024JC022154","url":null,"abstract":"<p>The East India Coastal Current (EICC) flows poleward along the east coast of India during spring and equatorward during winter. In the summer, it flows equatorward in the northern bay and poleward in the south, converging in the central part of the coast. Data from three pairs of HF radars located at three stations, Odisha (ORCO), Andhra Pradesh (APCO), and Tamil Nadu (TNCO), along the east coast of India are used in this study to present the characteristics and dynamics of eddies for a decade, from 2010 to 2020. The seasonal reversal of the EICC occurs through a gentle transition in the north, marked by strong offshore flows in the middle part of the coast, and eddies of different signs in the south. Eddy formation peaks in winter and most frequent off TNCO, followed by APCO and ORCO. Cyclonic eddies have longer lifespans and larger sizes in winter, while anticyclonic eddies show similar characteristics in spring. Most eddies have a radius between 10–30 km and life of 5 days. Seasonal mean Eddy Kinetic Energy (EKE) is higher in spring and winter, when EICC is well organized. Barotropic (BT) energy conversion takes place for all three stations for all seasons. Baroclinic (BC) energy transfer occurs in winter for all three stations and additionally off ORCO during summer. Spatial patterns of energy conversion occur in both mean-to-eddy and eddy-to-mean directions; they are spatially non-uniform and show marked differences between coastal and offshore regions.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315104","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":"An Assessment of Uncertainty in the ECCO Global Ocean-Sea Ice State Estimate Due To Atmospheric Forcing Uncertainty","authors":"Yanzhou Wei,&nbsp;Helen Pillar,&nbsp;Patrick Heimbach,&nbsp;An T. Nguyen,&nbsp;Gaël Forget,&nbsp;Ou Wang,&nbsp;Ichiro Fukumori,&nbsp;Ian Fenty,&nbsp;Martin Losch","doi":"10.1029/2024JC022191","DOIUrl":"https://doi.org/10.1029/2024JC022191","url":null,"abstract":"<p>The Estimating the Circulation and Climate of the Ocean (ECCO) state estimate is the result of adjusting a set of controls comprising atmospheric forcings, initial conditions, and mixing parameters to reduce model-data misfits. Despite this, uncertainties remain in the solution. Among others, small amplitude perturbations to the optimized controls may yield differences in the estimated state without notably increasing the misfits, providing distinct but equally acceptable solutions to the inverse problem. We focus on the impact of uncertainty in the atmospheric controls via ensemble perturbation. Our multivariate empirical orthogonal function (EOF) approach to construct the ensemble perturbations accounts for the covariance of control variables. Furthermore, it provides new insights into the space-time characteristics of ECCO's atmospheric adjustments. The two leading EOFs of these adjustments show a seasonal cycle dominated by high-latitude adjustments and a decadal component. Removing the time-mean of the adjustments results in large model-data misfits and thus unacceptable estimates. Ensemble perturbations in time-varying adjustments incur uneven uncertainties in oceanic metrics, for example, in global meridional heat transport (0.03 PW), the Atlantic meridional overturning circulation at 26°N (0.7 Sv), or ocean heat uptake (15 ZJ). These are an order of magnitude smaller than the uncertainty evaluated via ocean reanalysis intercomparisons and forward perturbation ensembles. The relatively weak impacts result from the relatively small amplitude of estimated atmospheric uncertainty in the ECCO release, out of sufficient consideration of a massive set of observational constraints. Future work should assess the impact of other sources of uncertainties.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC022191","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144315043","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":"Connecting the Deep Collection of Sinking Particles With Surface Ocean Signatures","authors":"Lu Wang,&nbsp;Jonathan Gula,&nbsp;Jérémy Collin,&nbsp;Laurent Mémery,&nbsp;Xiaolong Yu","doi":"10.1029/2024JC021777","DOIUrl":"https://doi.org/10.1029/2024JC021777","url":null,"abstract":"<p>A major pathway in the biological carbon pump is the gravitational sinking of organic particles from the sunlit ocean (0–200 m) to the deep ocean. Variability in particle fluxes measured by sediment traps is often attributed to variability in primary production in the surface ocean. However, particle fluxes are also influenced by physical processes such as mesoscale eddies and fronts. In this study, we assess the impact of upper-ocean dynamical structures on the variability of particle collection in the deep ocean. This is achieved by forward tracking the trajectories of 51.9 million virtual particles that were homogeneously released at a depth of 200 m with a constant sinking velocity of 50 m <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>d</mi>\u0000 <mrow>\u0000 <mo>−</mo>\u0000 <mn>1</mn>\u0000 </mrow>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${mathrm{d}}^{-1}$</annotation>\u0000 </semantics></math> in the Northeast Atlantic basin. We found that, despite a homogeneous particle source without biological effects, purely dynamical changes can induce heterogeneity in particle density and origin at depth. The position of sediment traps can thus significantly influence the weekly to seasonal particle collection in the deep ocean. Additionally, we identify and characterize nine particle clusters using a machine-learning approach. The results show that the seasonality of particle collection at depth can be induced by seasonal variations in upper-ocean flow structures. Clusters associated with eddy and frontal structures are found to intermittently contribute more than 50% of the particle amount during winter and spring, with smaller secondary peaks in the summer months. This study highlights the connection between mesoscale ocean dynamics and the spatio-temporal pattern of conservative (non-biological) particle collection in the deep ocean.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308992","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":"Flushing and Trapping of Buoyant Particles in a Gravitationally Driven Wide Estuary","authors":"R. Alan Mason,&nbsp;Tobias Kukulka,&nbsp;Robert J. Chant,&nbsp;Jonathan H. Cohen","doi":"10.1029/2025JC022417","DOIUrl":"https://doi.org/10.1029/2025JC022417","url":null,"abstract":"<p>Plastics and other buoyant particles, such as oil, plankton, and seafoam, are omnipresent in estuaries, which provide a critical interface to the open ocean. Here, we explore the convergence and along-channel transport of buoyant particles using an idealized model of the gravitationally driven estuarine circulation with a deeper center channel and shallower flanks. First, the model predicts persistent surface convergence zones, aggregating buoyant material. Second, reduced vertical mixing results in accelerated surface outflow consistent with particle transport out of the bay during neap tides. We refer to this consistent outflow as flushing. Third, increased vertical mixing from neap to spring tides changes the lateral structure of the surface flows with weak up-estuary along-channel flows in the region of particle convergence during spring tides, resulting in particle trapping. We show the applicability of idealized model theory to the Delaware Bay through the use of a realistic hydrodynamic model, high-resolution satellite images, GPS-tracked drifters, and CTD cross-sections. Our results are consistent with the theory and indicate that buoyant surface-trapped particles in Delaware Bay quickly converge to the channel center of the estuary and are consequently either trapped in the estuary during spring tide or flushed to the continental shelf during neap tide. Our results contribute to the growing understanding of particle movement and retention within an estuarine system.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308986","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":"Interplay Between Wind-Driven Advection and Mixing of Salt and Dissolved Oxygen in a Microtidal Estuary","authors":"Jianxing Wang,&nbsp;Johanna H. Rosman,&nbsp;James L. Hench,&nbsp;Nathan S. Hall,&nbsp;Anthony C. Whipple,&nbsp;Richard A. Luettich Jr.","doi":"10.1029/2025JC022802","DOIUrl":"https://doi.org/10.1029/2025JC022802","url":null,"abstract":"<p>Most work on how estuarine dynamics impact dissolved oxygen (DO) distributions has focused on tides, but in shallow estuaries with large fetch or small tides, wind can be the primary mixing agent and also drives advection. To investigate how these processes affect DO distributions, an observational study was conducted in the shallow, microtidal Neuse Estuary. Salinity, DO, and velocity profiles were measured at multiple positions along and across the estuary over a 6-month period. A one-dimensional model (General Ocean Turbulence Model) provided additional insight into the response of salinity and DO to wind. Salinity and oxygen conservation equation terms were calculated from observations and simulations. Cross-estuary wind drove lateral circulation and tilted the isohalines, reducing stratification; lateral advection and enhanced mixing reduced vertical gradients and increased the bottom DO. Down-estuary wind tended to increase the exchange flow and stratification, but concurrently the surface wind-mixed layer deepened over time. The balance of these processes determined if the water column became fully mixed or remained stratified, and the depth of the pycnocline and oxycline. An expression for steady state surface layer thickness was derived by considering the competition between the horizontal and vertical buoyancy flux, and the predictions agreed well with observations and simulations. Up-estuary wind inhibited the exchange flow and the combination of advection and mixing homogenized the water column. While these patterns generally held for purely across- or along-channel wind, the response was often more complex as the wind vector varied in orientation and with time.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 6","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144300241","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}