Journal of Geophysical Research-Oceans最新文献

{"title":"Dipole Eddies Change Per- and Polyfluoroalkyl Substances Spatial Profiles in the Western North Pacific Subtropical Gyre","authors":"Bowen Hou,&nbsp;Jialin Tang,&nbsp;Qijun Gong,&nbsp;Lilan Zhang,&nbsp;Dong Sun","doi":"10.1029/2025JC022875","DOIUrl":"https://doi.org/10.1029/2025JC022875","url":null,"abstract":"<p>Ocean currents are deemed as the main drivers for global distribution of per- and polyfluoroalkyl substances (PFAS). Mesoscale eddies are ubiquitous in the ocean and can strongly alter both horizontal and vertical circulation, thereby affecting PFAS distributions. A clear understanding of the influence of mesoscale eddies on PFAS distribution is critical for protecting ocean health, yet this influence remains poorly understood. In this study, we tracked a cyclone–anticyclone dipole eddy in the western North Pacific Subtropical Gyre, one of the most oligotrophic regions of the global ocean, and collected 72 samples from 12 stations (6 in the anticyclone, 3 in the cyclone, and 3 in the reference area (RA) outside the cyclone) at depths down to 1,000 m. Mesoscale eddies induced pronounced vertical and horizontal heterogeneity in PFAS concentrations. In the RA and cyclone, the highest concentrations of PFAS were found in the 50 m layer, while in the anticyclone, the maximum occurred in the deep chlorophyll maximum layer (100–131 m). This pattern can be attributed to upwelling in the cyclone, which impedes the downward transport of PFAS, whereas downwelling in the anticyclone facilitates it. Notably, the complex hydrodynamics at the interaction front of the dipole eddies led to PFAS concentrations 2–7 times higher than those in surrounding waters at the same depth. This created a pronounced PFAS hotspot and elevated the exposure risk for organisms abundant in the frontal zone. This study is the first observational investigation to decipher the impact of mesoscale eddies, one of the most widespread and important dynamical phenomena in the oceans, on PFAS distribution.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224323","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 East Greenland Polar Front as a Mediator of Climate-Ocean-Ecosystem Variability Along Southeast Greenland","authors":"C. V. B. Gjelstrup,&nbsp;J. Boje,&nbsp;B. R. MacKenzie,&nbsp;S. Post,&nbsp;K. M. Werner,&nbsp;A. W. Visser,&nbsp;C. A. Stedmon","doi":"10.1029/2025JC022669","DOIUrl":"https://doi.org/10.1029/2025JC022669","url":null,"abstract":"<p>The southeast Greenland region features a confluence of Arctic- and Atlantic origin waters along the continental shelf-break, forming the East Greenland Polar Front (EGPF). Here we examine the role of the EGPF in mediating climate-ocean-ecosystem variability. We observe systematic temporal variability in frontal intensity related to regional subpolar gyre (SPG) dynamics via gyre spin-up. By combining sea surface temperature derived frontal metrics with sea surface height, sea-ice concentration, surface chlorophyll-<i>a</i> concentration, and fisheries survey data, we demonstrate how gyre-induced oceanic variability is reflected in the shelf ecosystem. Elevated chlorophyll-<i>a</i> concentrations along the continental slope correspond to periods when the SPG is in a negative phase, the Irminger Gyre is spun-up and the EGPF is strong. This response in chlorophyll-<i>a</i> is likely due to a combination of aggregation of phytoplankton at the frontal zone and enhanced new production fueled by increased nutrient availability. In addition to the temporal variability, the EGPF exhibits spatial variability on seasonal and interannual timescales across the wide Ammassalik shelf. As such, the EGPF has migrated 90 km shoreward in tandem with sea-ice retreat since the early 2010s. This migration led to increased chlorophyll-<i>a</i> concentrations over shallow banks and decreased chlorophyll-<i>a</i> concentrations over the outer shelf and slope areas. Our findings underscore the critical role of the EGPF in mediating interactions between the physical and biological components of the southeast Greenland ecosystem.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022669","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223785","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":"Seasonal Variability and Nonlinear Interactions of Near-Inertial Waves and Internal Tides Near the Xisha Islands","authors":"Qian Liu,&nbsp;Yue Teng,&nbsp;Huan Mei,&nbsp;Xiangbai Wu,&nbsp;Daiyu Zhang,&nbsp;Jie Zhang,&nbsp;Jingnan Yin,&nbsp;Xiaodong Shang","doi":"10.1029/2025JC022366","DOIUrl":"https://doi.org/10.1029/2025JC022366","url":null,"abstract":"<p>Based on nearly 8 years of moored observations, this study investigates the seasonal variability and dynamical interactions of near-inertial waves (NIWs) and internal tides (ITs) near the Xisha Islands in the northern South China Sea (SCS). Near-inertial waves (NIWs) are most energetic in autumn and winter, coinciding with frequent typhoon activity, whereas ITs follow a semiannual cycle with peaks in summer and winter. Modal analysis reveals that ITs are dominated by low modes, whereas NIWs exhibit variable vertical structures shaped by typhoon forcing and mesoscale eddy activity. A case study in autumn 2011 highlights the critical role of a cyclonic eddy (CE) in modulating NIWs. Energy budget analyses show that the net transfer from the CE to NIWs accounted for nearly 85% of the observed enhancement of near-inertial kinetic energy (NIKE), supporting its downward penetration to 543 m. Importantly, this transfer occurred even though the background flow energy was much stronger, indicating that NIWs can still gain substantial energy input under highly unbalanced flow-wave energy conditions. Typhoon-generated NIWs, characterized by strong shear, further dominated nonlinear interactions with ITs, leading to the intensification of coupled internal waves. These results underscore the combined influence of atmospheric forcing and mesoscale dynamics on internal wave energetics, providing new insights into energy pathways, eddy-wave coupling, and the regulation of mixing and momentum transport in the tropical ocean.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223784","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 Reduced Ventilation in Meridional Overturning Circulation: Evidence From Physical and Biogeochemical Changes in Repeat Observations Along 110°E","authors":"Meng Han,&nbsp;Helen E. Phillips,&nbsp;Nathaniel L. Bindoff,&nbsp;Ming Feng,&nbsp;Ramkrushnbhai S. Patel","doi":"10.1029/2025JC023018","DOIUrl":"https://doi.org/10.1029/2025JC023018","url":null,"abstract":"<p>Two hydrographic voyages conducted 56 years apart (in 1963 and 2019) along 110°E in the southeast Indian Ocean reveal significant long-term changes in water mass properties. We focus on physical and biogeochemical changes in Subtropical Water (STW), Subantarctic Mode Water (SAMW), and Antarctic Intermediate Water (AAIW)—key components of the Indian Ocean shallow and global overturning circulations. Changes in temperature and salinity are decomposed into spice (along-isopycnal) and heave (vertical movement of isopycnals) components. STW has become warmer and saltier on isopycnals. In contrast, SAMW and upper AAIW have cooled and freshened primarily due to spice changes, suggesting salinity-driven processes originating from their respective source regions. Meanwhile, the lower AAIW shows warming and salinification, indicating temperature-driven changes and distinct source variability. The observed thickening of the SAMW and AAIW layers, combined with increased apparent oxygen utilizations, nitrate, and phosphate concentrations, points to reduced ventilation and enhanced stratification. These changes imply a slowdown in circulation and altered nutrient cycling consistent with anthropogenic climate change impacts.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145223831","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":"Bifurcated Upshelf Extension of the Yangtze River Plume","authors":"Renxin Huang,&nbsp;Long Jiang,&nbsp;Xuhua Cheng,&nbsp;Hans Burchard","doi":"10.1029/2025JC022937","DOIUrl":"https://doi.org/10.1029/2025JC022937","url":null,"abstract":"<p>Upshelf extension describes a river plume propagating in the opposite direction of the Kelvin wave that develops under various mechanisms. In this study, we observed two simultaneous upshelf branches in the Yangtze River (YR) plume in field monitoring, which were reproduced and investigated using a three-dimensional hydrodynamic model. A 12-year (2010–2021) realistic simulation indicates that the inshore branch appears on average 88% of the time correlated with river discharge, while the offshore branch occurs as several single events of 4–10 days in summer. Momentum and vorticity budget analyses and numerical experiments suggest that the homogeneous inshore branch develops in the absence of external forcing (e.g., winds, tides, ambient currents). Within the trapping depth of the bottom-advected YR plume, the upshelf motion tends to cross the isobaths into shallower inshore areas, facilitated by the barotropic pressure gradient and slope-induced inertia. Beyond the trapping depth, the plume expands radially offshore at the surface. The realistic plume oscillates with tidal mixing and trapping depth between these two modes in the spring-neap cycle. In comparison, the offshore branch results from wind entrainment during upwelling-favorable events, but is only formed around neap tides, when the wind-driven surface and tide-induced bottom Ekman layers are decoupled. Sufficient wind stress and duration and essential tide conditions to force the offshore branch were quantified. By contrasting properties and drivers of the two upshelf branches, this study sheds light on potential physical controls of upshelf motion in river plumes and has local implications for surrounding coastal and shelf waters.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224053","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":"Estimating Air-Sea Fluxes of CO2 in the River Influenced Northern Gulf of Mexico Shelf Utilizing 226Ra-222Rn Disequilibria","authors":"Manab Kumar Dutta,&nbsp;Jocelyn Forsman,&nbsp;Kanchan Maiti","doi":"10.1029/2025JC022794","DOIUrl":"https://doi.org/10.1029/2025JC022794","url":null,"abstract":"<p>Air-water CO₂ fluxes were estimated from the shallow shelf region of the Mississippi River-influenced northern Gulf of Mexico using a traditional wind-based approach and a ²²⁶Ra-²²²Rn disequilibria approach. Flux measurements were carried out from two contrasting regions of the shelf: the Wax Lake Delta (WLD, a propagating delta) and Barataria Bay (BB, a degrading delta) during early summer (high river flow) and fall (low river flow) in 2019. On average, surface water <i>p</i>CO₂ for WLD varied between 275–1,487 μatm in early summer and 381–1,267 μatm in fall, while BB was mostly CO₂ undersaturated, ranging from 212 to 289 μatm and 336 to 414 μatm, respectively. The freshwater discharge largely controlled <i>p</i>CO₂ in the near-shore region, whereas community metabolism was the dominant process farther offshore. Wind-based estimates of CO₂ fluxes varied between −1–28 and −9–0.2 mmol m⁻² d⁻¹ whereas radiometric-based estimates varied between −6–6 and −48–5 mmol m⁻² d⁻¹ for WLD and BB, respectively. The near-shore region was found to be a source of CO₂ for the atmosphere. Our results show that gas transfer velocities estimated by the radiometric approach were consistently higher than the wind-based approach at water depths of 20–40 m. This suggests that processes other than wind velocity, such as turbulence, fetch, and chemical enhancement, can play an important role in air-sea exchange of CO₂ in the shallow shelf region.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224052","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":"Wind-Driven Mid-Depth Pacific Cooling in a Dynamically Consistent Ocean State Estimate","authors":"Anthony Meza,&nbsp;Geoffrey Gebbie","doi":"10.1029/2025JC022462","DOIUrl":"https://doi.org/10.1029/2025JC022462","url":null,"abstract":"&lt;p&gt;A comparison of 19th century HMS Challenger hydrography with modern observations indicated the mid-depth Pacific has cooled at a rate of &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;5&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $5pm 3$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; centikelvin (cK, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;1&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;cK&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;0.01&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;kelvin&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $1,mathrm{cK}=0.01,mathrm{kelvin}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) per century and could be explained as a slow ongoing adjustment to the Little Ice Age. The historical hydrographic data was sparse, however, and limited by 19th century technology. Observations from recent decades are more plentiful, with &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;1&lt;/mn&gt;\u0000 &lt;msup&gt;\u0000 &lt;mn&gt;0&lt;/mn&gt;\u0000 &lt;mn&gt;3&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $mathcal{O}left(1{0}^{3}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; times more observations are used to constrain the dynamically consistent ocean state estimate produced by the Estimating the Circulation and Climate of the Ocean (ECCO) Consortium, for example. We find the ECCO mid-depth Pacific cooling trend is similar in magnitude (5 cK/century) and spatial structure to HMS Challenger data. Additionally, cooling in the mid-depth North Pacific only emerges after the model is optimized to observations. Here, sensitivity experiments are used to isolate the effects of data-constrained model parameters on temperature trends in this region. The optimized wind stress achieves most (3 cK/century) of the cooling in ECCO through anomalous vertical transport and adiabatic isopycnal upwelling. Optimized initial conditions and mixing coefficients play a less important role, causing cooling rates of 2 cK/century and 1 cK/century, respectively. Furthermore, the ECCO heat budget is found to be kinematically similar to that expected from a centuries-long simulation of pre-industrial anomalies being transported into the ocean interior. Thus, mid-depth cooling in ECCO can be physically interpreted and is within the dyna","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022462","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224549","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":"Spectral Refraction Modeling of Waves Around the Steep Reef at Palau","authors":"Mika N. Siegelman,&nbsp;William C. O’Reilly,&nbsp;Janet Becker,&nbsp;Raymond Young,&nbsp;Corey Olfe,&nbsp;Patrick L. Colin,&nbsp;Eric Terrill,&nbsp;Sophia Merrifield","doi":"10.1029/2025JC022391","DOIUrl":"https://doi.org/10.1029/2025JC022391","url":null,"abstract":"<p>Western Pacific islands, such as Palau, are susceptible to wave-driven inundation due to low land elevations and limited space for coastal retreat. Assessing the impacts of extreme wave events on these low-lying islands requires regional numerical models that account for remotely generated waves from all directions and that resolve the complex bathymetry surrounding the islands. Such models often are computationally expensive and impractical for operational forecasts. In this study, eight years of wave observations from 10 sites around the island chain of Palau, at depths ranging from 9.4 to 17.6 m, are used to characterize the spatial variability of the island group's wave climate and to test the ability of a spectral refraction model to downscale regional wave hindcasts and reproduce the observed incident conditions. The spectral refraction model demonstrates significant skill predicting reef edge significant wave heights (mean <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msup>\u0000 <mi>r</mi>\u0000 <mn>2</mn>\u0000 </msup>\u0000 </mrow>\u0000 <annotation> ${r}^{2}$</annotation>\u0000 </semantics></math> = 0.77, mean <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>R</mi>\u0000 <mi>M</mi>\u0000 <mi>S</mi>\u0000 <mi>E</mi>\u0000 </mrow>\u0000 <annotation> $RMSE$</annotation>\u0000 </semantics></math> = 0.21 m) at the locations of our island scale wave gauge array and outperforms a regional 7 km resolution hindcast product based upon the WaveWatch III community model (Smith et al., 2021, https://doi.org/10.1002/gdj3.104). Furthermore, the spectral refraction model accurately downscales wave predictions during Typhoon Lan demonstrating its potential for operational forecasting and place-based damage and risk assessments during extreme events. When used with deep-water wind-wave models as input, spectral refraction methods can significantly improve reef edge incident wave boundary conditions necessary for shallow water reef modeling with low computational cost.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022391","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224454","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":"Unveiling the Complex Structure of Vertical Mode-Two Kelvin Waves Driving Strong Nearshore Currents in Large, Deep Lake Geneva","authors":"Rafael Sebastian Reiss,&nbsp;Ulrich Lemmin,&nbsp;François Mettra,&nbsp;Seyed Mahmood Hamze-Ziabari,&nbsp;David Andrew Barry","doi":"10.1029/2025JC022353","DOIUrl":"https://doi.org/10.1029/2025JC022353","url":null,"abstract":"<p>Although vertical mode-one (V1) Kelvin waves are known to play an important role in nearshore dynamics of large lakes, observations of vertical mode-two (V2) Kelvin waves are scarce, and their characteristics and significance are largely unknown. Combining field observations, 3D hydrodynamic modeling, and particle tracking, we demonstrate that previously undetected V2 Kelvin waves are common in Lake Geneva (Switzerland/France) during summer. V2 Kelvin waves with a 5-d period persisted for over one month in 2021 and 2022. Modeling revealed a complex, spatially heterogeneous vertical structure. Since the lower nodal line depth varied from ∼150 to 200 m near the shores to ∼75 m in the lake center, V2 Kelvin waves were restricted to the deep eastern basin (maximum depth 309 m), and nearshore current profiles observed at ∼110-m depth did not show the typical V2 modal structure. The waves produced large vertical isotherm displacements (∼25 m) and strong currents (∼28 cm s⁻¹) in the nearshore thermocline and induced alongshore transport over nearly half the basin length. Currents were strongest ∼1 km from shore and decreased exponentially toward the lake center. Our findings explain why previous studies in Lake Geneva's nearshore regions (out to ∼75-m depth) only detected V1 Kelvin waves and no V2 Kelvin waves. Modeling revealed that V2 Kelvin waves are consistently excited under typical summer stratification and wind forcing conditions. Our results suggest that these waves occur in other large deep lakes having a Burger number <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>S</mi>\u0000 <mrow>\u0000 <mi>V</mi>\u0000 <mn>2</mn>\u0000 </mrow>\u0000 </msub>\u0000 <mo>≈</mo>\u0000 <mn>0.1</mn>\u0000 </mrow>\u0000 <annotation> ${S}_{V2}mathit{approx }0.1$</annotation>\u0000 </semantics></math>, with important implications for the transport and dispersion of sediments, nutrients, and pollutants.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 10","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022353","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224455","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":"Importance of Strains in Kinetic Energy Flux for Submesoscale Processes From an Anisotropic Perspective","authors":"Jun Yang,&nbsp;Dongxiao Wang,&nbsp;Chunhua Qiu,&nbsp;Xiaoming Zhai,&nbsp;Ru Chen,&nbsp;Jiawei Qiao,&nbsp;Bo Hong","doi":"10.1029/2024JC022186","DOIUrl":"https://doi.org/10.1029/2024JC022186","url":null,"abstract":"<p>Submesoscale fronts and filaments are jet-like motions, associated with cross-scale kinetic energy (KE) flux through eddy-mean flow interaction. However, the diagnostic method for KE flux in jets with a steady zonal flow axis is not suitable for submesoscale processes with arbitrary axes. Based on a high-resolution ocean model and observations, we propose a method for diagnosing KE flux via mesoscale strains and submesoscale stresses from an anisotropic perspective. Furthermore, we develop a three-dimensional anisotropic KE flux algorithm under the hydrostatic assumption, which is important for diagnosing the energy sources and distributions of submesoscale vertical instabilities. Horizontally, we find that the inverse KE cascade mainly arises from shear strain throughout the filament's lifespan, triggering anisotropic frontogenesis and ageostrophic secondary circulations (ASCs). In ASCs, the cross-filament shear strain provides an energy source for the geostrophic shear production (GSP) and causes the forward flux through the symmetric instability. Meanwhile, the forward KE flux caused by the centrifugal instability can reach 35% of GSP which is regulated by the anisotropic eddy KE but has been neglected in previous studies. This finding effectively explains the directional dependence of strains, stresses, and instabilities, broadening our understanding of energy balance and providing a foundation for improving submesoscale parameterizations.</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":"145224548","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}