Journal of Geophysical Research-Oceans最新文献

{"title":"Impact of Synoptic-Scale Atmospheric Forcing Conditions on Deep Convection in the Labrador Sea","authors":"R. Piunno,&nbsp;G. W. K. Moore,&nbsp;K. Våge","doi":"10.1029/2024JC021818","DOIUrl":"https://doi.org/10.1029/2024JC021818","url":null,"abstract":"<p>During the winter season, stratification in the central Labrador Sea is eroded by surface heat fluxes causing convective overturning exceeding depths of 2 km. This is one of the few locations globally in which deep convection occurs, making it an important feature of the climate system and ocean ventilation. Large-scale atmospheric circulation patterns modulate the air-sea interaction that drives the loss of ocean buoyancy. Here, we investigate the process by which weather patterns driven by the North Atlantic Oscillation (NAO), and its northern center of action, the Icelandic Low, modulate convective depths. A one-dimensional ocean model is used to quantify the mixed layer depth's response to various atmospheric forcing conditions. We find that while net heat flux is the strongest modulating factor of mixed layer depth's seasonal maximum, it is also strongly affected by the NAO. The Icelandic Low, despite its proximity to the Labrador Sea, does not affect mixed layer deepening as strongly. From geospatial correlation fields with heat flux, NAO, and Icelandic Low time series, it is evident that the NAO more efficiently regulates strong, cold, westerly winds from over the North American continent, which are more effective at cooling the ocean surface boundary layer. Understanding these dynamics is crucial for predicting future changes in ocean ventilation and its impact on global climate patterns.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021818","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707348","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":"The Life Cycle of the Low Salinity Lenses at the Surface of the Arctic Ocean","authors":"Clément Van Straaten,&nbsp;Camille Lique,&nbsp;Nicolas Kolodziejcyk","doi":"10.1029/2024JC021699","DOIUrl":"https://doi.org/10.1029/2024JC021699","url":null,"abstract":"<p>In the Arctic Ocean, coherent low salinity anomalies, known as lenses, are often observed at the surface and are thought to result from the input of large amounts of freshwater from sea ice melting and river runoff. In this study, we perform a systematic detection of these lenses and track their displacements in a 21-year simulation performed with a high resolution ocean-sea ice regional model of the Arctic in order to gain a better understanding of their life cycle. Two thirds of the lenses are formed during summer, in response to sea ice melt, river discharge, or are colocated with mesoscale eddies. They are then able to persist for weeks to months, traveling long distance across the basin as their characteristic surface salinity anomalies get eroded through vertical processes. Throughout their life, the lenses are associated with larger sea ice melting flux during summer and concentrate stronger sea ice formation than their surroundings by up to 50%. Over the 21-year period, the number of lenses has increased by <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>∼</mo>\u0000 </mrow>\u0000 <annotation> ${sim} $</annotation>\u0000 </semantics></math>2%/year over the Arctic Ocean, and the formation locations have shifted following the retreat of the sea ice edge in regions such as Greenland, Barents, and Chukchi seas. Our results suggest that these localized, intermittent and coherent lenses may be important for the large scale Arctic dynamics and the ocean-sea ice interaction.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021699","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707344","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":"Estimation of Roughness Height on Oyster Reefs","authors":"M. Lee,&nbsp;Y. S. Park,&nbsp;H. Noh,&nbsp;B. Kim,&nbsp;S. J. Baek","doi":"10.1029/2024JC021888","DOIUrl":"https://doi.org/10.1029/2024JC021888","url":null,"abstract":"<p>Oyster reefs play a crucial role in coastal protection by attenuating waves and currents, thereby contributing to coastal stability. This protective function is largely due to the significantly greater roughness height of oyster reefs than bare sand surfaces. There is limited understanding of the characteristic length and the appropriate estimation equation needed to determine the roughness height of oyster reefs. To address this, experiments were conducted under both unidirectional and oscillatory flow conditions to explore the relationship between the geometry of oyster reefs and their roughness height. The experimental results indicate a correlation between the hydraulic roughness height and the height of their surface rough elements. Furthermore, the study proposes a unified roughness height formula that is applicable to both unidirectional and oscillatory flows. The validity of this formula is assessed through its application to the log law and comparison with experimental data. The findings of this study facilitate the estimation of the roughness height of oyster reefs, which is essential for understanding their hydraulic characteristics and their role in coastal protection.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021888","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143707479","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":"Synoptic Observations of Near-Inertial Motions in an Enclosed Basin","authors":"Erica L. Green,&nbsp;Samuel M. Kelly,&nbsp;Andrew J. Lucas,&nbsp;Jay A. Austin,&nbsp;Jonathan D. Nash","doi":"10.1029/2024JC021828","DOIUrl":"https://doi.org/10.1029/2024JC021828","url":null,"abstract":"&lt;p&gt;Near-inertial motions are common in the coastal ocean, producing significant currents, isopycnal displacements, and turbulent mixing. Unknown fractions of near-inertial energy are locally dissipated in the mixed layer and converted to offshore propagating internal waves along the coast. Here, we examine near-inertial motions from July to October 2017 at 10 moorings in Lake Superior, which provides a natural laboratory for the coastal ocean. The lake has an approximate two-layer structure and is dominated by near-inertial currents that reach 0.50 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; and isopycnal displacements that reach 10 m. Average mode-1 near-inertial kinetic energy (KE) and available potential energy (APE) are 320 J &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;m&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{m}}^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; and 10 J &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;m&lt;/mi&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{m}}^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, respectively. KE is inhibited near the coast and APE has no basin-wide structure. Velocity is separated into a basin-averaged inertial oscillation (IO) and a near inertial wave (NIW) residual. A slab model explains 87% of the IO variance, while the NIW field exhibits 5 W &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;m&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; ${mathrm{m}}^{-1}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; offshore energy fluxes along the coasts, a group speed of 0.1 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 ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021828","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689898","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":"The Role of Wind and Buoyancy in a Turbulence-Resolving Model of the Atlantic Meridional Overturning Circulation","authors":"Bahman Ghasemi,&nbsp;Catherine A. Vreugdenhil,&nbsp;Bishakhdatta Gayen","doi":"10.1029/2024JC021790","DOIUrl":"https://doi.org/10.1029/2024JC021790","url":null,"abstract":"<p>The Atlantic meridional overturning circulation (AMOC) in the North Atlantic Ocean is shaped by mechanical and buoyancy forcing, with critical components like the Gulf Stream, gyres, dense water formation, and deep water upwelling. The AMOC is undergoing significant variability due to changes in forcing from the rapidly changing climate. However, limited understanding and resolution in capturing deep convection and boundary layer dynamics lead to inaccuracies in future ocean mass and heat transport estimations. This study employs novel turbulence- and convection-resolving simulations of an idealized, laboratory-scale North Atlantic Ocean model to investigate these effects. The simulation captures key features observed in the North Atlantic Ocean, including the AMOC, downwelling and upwelling, boundary currents, thermocline layers, gyres, fronts, and baroclinic eddies. With the presence of wind, two distinct thermocline layers form in the subtropics due to Ekman pumping: the “ventilated thermocline” near the surface and the “internal thermocline” below. We examine two scaling theories to quantify meridional and gyre transport based on these thermocline layers. Our findings indicate that meridional transport increases with both buoyancy and wind forcing, while zonal transport is enhanced by wind and shows some dependence on buoyancy forcing. We find that upwelling near the western boundary intensifies with increased wind and buoyancy forcing, while downwelling from convection occurs along the northeastern boundary and from Ekman pumping in the subtropics, highlighting the three-dimensional structure of the AMOC. Our results demonstrate the interconnectedness of gyres and deep overturning circulation, offering insights toward refining turbulence and convection parameterizations in ocean models.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021790","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689941","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":"Variability of the South Pacific Eastern Subtropical Mode Water and Associated Causal Mechanism During the Argo Period","authors":"Guimin Sun,&nbsp;Jifeng Qi,&nbsp;Tangdong Qu,&nbsp;Baoshu Yin","doi":"10.1029/2024JC022254","DOIUrl":"https://doi.org/10.1029/2024JC022254","url":null,"abstract":"<p>Variability of the South Pacific eastern subtropical mode water (SPESTMW) is investigated using Argo data and ERA5 reanalysis products, with particular attention paid to its connection to the El Niño-Southern Oscillation (ENSO). Our analysis shows significant seasonal variation in the SPESTMW volume, reaching its maximum (minimum) in November (July). Changes in the mixed layer depth (MLD) dominated by shortwave radiation are the main cause of this seasonal variation. In contrast, latent heat flux is primarily responsible for the MLD and SPESTMW variability on interannual timescales. There is a considerable association between the SPESTMW volume and ENSO, decreasing (increasing) during El Niño (La Niña) years. Further analysis of ERA5 reanalysis products indicates that anomalous winds associated with ENSO modulate surface latent heat flux via evaporation, which further alters the MLD and the SPESTMW volume. Our analysis also reveals significant differences in the SPESTMW response to the central and eastern Pacific El Niño, implying potential importance of the SPESTMW in regional ocean and climate variability.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC022254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689940","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 Divergence and Vorticity View of Nonlinear Oceanic Lee Wave Obtained by a Two-Vessel Survey","authors":"Tsai-Ling Chuang,&nbsp;Jia-Lin Chen,&nbsp;Ming-Huei Chang,&nbsp;Ren-Chieh Lien,&nbsp;Yu-Hsin Cheng,&nbsp;Yiing Jang Yang,&nbsp;Sen Jan,&nbsp;Anda Vladoiu","doi":"10.1029/2024JC021422","DOIUrl":"https://doi.org/10.1029/2024JC021422","url":null,"abstract":"&lt;p&gt;The spatial distribution of the flow field inferred from shipboard measurements often suffers from a spatial-temporal aliasing effect. This study examined a detailed view of the horizontal divergence and relative vertical vorticity captured by a two-vessel survey to characterize velocity gradients and the resulting process in the presence of nonlinear lee waves. The three-dimensional structure of the horizontal velocity gradients and turbulent mixing within a nonlinear internal lee wave behind a shallow seamount was investigated. Synchronous two-vessel Acoustic Doppler Current Profilers provide in-situ measurements of velocity vectors that significantly minimize the spatial and temporal aliasing effect. The magnitude of horizontal divergence and relative vertical vorticity normalized by the planetary vorticity (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;δ&lt;/mi&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mi&gt;f&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $delta /f$&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;mi&gt;ζ&lt;/mi&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mi&gt;f&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $zeta /f$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; ∼ O (10)) is one order of magnitude greater than prior observations in the typical oceanic sub-mesoscale flow field using a two-vessel survey. Our analysis indicates that the spatial variations of horizontal divergence and relative vertical vorticity over the seamount are associated with flow-topography interactions. Owing to the bottom Ekman effect, the deflected Kuroshio enhances the relative vertical vorticity, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ζ&lt;/mi&gt;\u0000 &lt;mi&gt;z&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;msub&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mo&gt;∂&lt;/mo&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;V&lt;/mi&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;msub&gt;\u0000 &lt;mo&gt;∂&lt;/mo&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mi&gt;U&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${zeta }_{z},{=mathit{partial }}_{x}V-{mathit{partial }}_{y}U$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and horizontal components of relative vorticity, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;ζ&lt;/mi&gt;\u0000 &lt;mi&gt;x&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021422","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689934","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":"Contrasting Impacts of Two Types of El Niño on Interannual Variations of Marine Heatwaves in the South China Sea","authors":"Ningning Zhang,&nbsp;Jian Lan,&nbsp;Wenjin Sun,&nbsp;Changming Dong","doi":"10.1029/2024JC021991","DOIUrl":"https://doi.org/10.1029/2024JC021991","url":null,"abstract":"<p>This study utilizes multiple observational and reanalysis data sets to investigate the contrasting effects of Eastern Pacific (EP) and Central Pacific (CP) El Niño on interannual variations of marine heatwaves (MHWs) in the South China Sea (SCS) from the developing autumn to decaying summer of El Niño. EP El Niño is associated with more frequent, intense, and prolonged MHWs throughout its life cycle, while CP El Niño is linked to a general decrease in MHW characteristics, except in decaying summer. During EP El Niño, an anomalous anticyclone over the SCS during developing autumn induces warming mainly by increasing shortwave radiation and diminishing latent heat release, fostering MHW development. The anomalous warming persists into decaying summer, intensified by the influence of an anticyclone associated with the western North Pacific subtropical high (WNPSH). Reduced MHWs during CP El Niño are primarily attributed to cooling in developing autumn and early cessation of warming in decaying summer. This autumn cooling is connected to enhanced latent heat release, anomalous Ekman upwelling, and negative horizontal advection caused by an anomalous cyclone around the SCS. The early fade of summer warming in CP El Niño is due to the northeastward shift of the WNPSH compared to the EP El Niño scenario, which reduces its ability to warm the SCS. The sea surface temperature (SST) evolutions during CP El Niño events highlight the thermal status of developing autumn and decaying summer as critical factors for MHW occurrence and persistence, underscoring the necessity to assess the thermal state preceding SST increases in MHW research.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689935","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 and Decadal Geostrophic Pathways of Pacific and Atlantic Waters in the Arctic Amerasian Basin From Observations","authors":"Noémie Planat,&nbsp;L. Bruno Tremblay,&nbsp;Carolina O. Dufour,&nbsp;David Straub","doi":"10.1029/2024JC021560","DOIUrl":"https://doi.org/10.1029/2024JC021560","url":null,"abstract":"<p>We examine the geostrophic pathways of Pacific and Atlantic Waters along isopycnal surfaces of the Arctic Ocean from Montgomery potentials using two observation-based climatologies: the World Ocean Atlas and the Monthly Isopycnal &amp; Mixed-layer Ocean Climatology. The decadal mean circulation (2005–2017) shows an anticyclonic circulation for both the summer Pacific Waters (sPW) and winter Pacific Waters (wPW, although somewhat weaker) in the Canada Basin with subduction along the Chukchi plateau for both water masses. On the wPW layer, the diagnostics also highlight a year-long persistent flow from Herald Canyon on Chukchi Shelf to the Canadian Arctic Archipelago around the Canada Basin. Outflows are found at Nares and Fram Sraits at the density of sPW and wPW. These outflowing waters, previously reported as Pacific Waters, are found here to originate from the Eurasian shelf. Deeper, the Atlantic Waters flow anticyclonically around Northwind Ridge and cyclonically along the Alaskan shelfbreak forming a boundary current. The subduction of warm water along the Alaskan and Chukchi shelves is found to occur in summer on the sPW isopycnal layer, thus contributing to transferring heat into the center of the gyre. However, an advection of virtual Lagrangian particles from Pt. Barrow suggests that processes operating on timescales shorter than a month or at interannual timescales are the main contributors to the heat build up observed over the past two decades. This analysis supports the hypothesis that high frequency processes are key in shaping the subsurface heat reservoir of the Canada Basin.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021560","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689436","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":"Decadal Linkage of Sea Level Anomalies Between the South China Sea and Western Tropical Pacific","authors":"Qin Duan,&nbsp;Tianyu Wang,&nbsp;Yuhong Zhang,&nbsp;Yan Du","doi":"10.1029/2024JC021618","DOIUrl":"https://doi.org/10.1029/2024JC021618","url":null,"abstract":"<p>The decadal variability of sea level anomalies (SLA) in the South China Sea (SCS) is coherent with those in the Western Tropical Pacific (WTP), and both correlate with the Pacific Decadal Oscillation (PDO) with changing correlation across different decades, characterized by an enhanced relationship after 1993. This study analyzed the underlying factors in the relationship between SLA in the SCS and PDO based on observations and simple ocean model experiments. The results reveal that the key factor is the anomalous atmospheric anticyclonic circulation over the tropical western North Pacific (WNPAAC), which can induce positive decadal SLA responses. The WNPAAC index, defined as the regional mean Wind Stress Curl in the Tropical Western North Pacific (TWNP, 3°–18°N, 130°E–160°W), exhibits a negative correlation (<i>r</i> = −0.68 for 1940–2022, exceeding the 95% confidence level) with the decadal steric sea level first mode principal component of empirical orthogonal function. The index can thus characterize the decadal SLA variations in the SCS and the WTP well. Sensitivity experiments using a 1.5-layer nonlinear Reduced-Gravity Ocean model demonstrate that the TWNP wind field accounts for most of the decadal SLA variations in the SCS, with an explained variance percentage (skill) of 60.95%. This study suggests that the TWNP wind field, influenced by tropical central Pacific sea surface temperature anomalies through the Matsuno-Gill response after 1965, dominates decadal SLA variability in the SCS. This wind field functions as a subsystem within the PDO dynamics, showing relative independence from the PDO.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 3","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689381","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}