Journal of Geophysical Research-Oceans最新文献

{"title":"Trends and Variability in Depth and Spiciness of Subsurface Isopycnals on the Vancouver Island Continental Shelf and Slope","authors":"M. Maier,&nbsp;D. Ianson,&nbsp;R. C. Hamme","doi":"10.1029/2024JC020992","DOIUrl":"https://doi.org/10.1029/2024JC020992","url":null,"abstract":"<p>The waters over the southern Vancouver Island shelf and slope are productive, economically important regions. The circulation is highly dynamic through variable mixing of both younger subarctic and older southern water masses, and significant local upwelling and downwelling regimes. We take advantage of three time series that cover more than three decades: the La-Perouse, Line-P, and CalCOFI time series, each covering at least 37 years (1984–2021). We investigate subsurface salinity, temperature, and depth observations to study seasonal and interannual variability in isopycnal heave and spiciness, and evaluate possible trends. The 26.6 kg m⁻³ isopycnal is the deepest isopycnal that is regularly upwelled onto the Vancouver Island shelf (above 200 m), shoaling over 100 m seasonally. Spiciness on the 26.6 isopycnal is highest in winter, but seasonal variability is much smaller than the interannual variability, which itself is two to three times smaller than the variability in adjacent subarctic waters and in the California Undercurrent further south, prior to their arrival in our study region. Spiciness in subsurface shelf waters appears to have been increasing over the past 37 years, by about half the magnitude of the increase in spiciness observed in the California Undercurrent water. In contrast, the subsurface slope shows no trend in spiciness but appears to be experiencing physical convergence, specifically an increase in the volume of water with a density of around 26.6 kg m⁻³, which has also been observed in the subarctic northeast Pacific, at Ocean Station Papa.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC020992","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818373","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":"Vertical Transport by Frontal Subduction Alleviating Hypoxia in a Highly Stratified Estuary","authors":"Keyan Liu,&nbsp;Jiaxue Wu,&nbsp;Yongsheng Cui,&nbsp;Chao Li","doi":"10.1029/2024JC021932","DOIUrl":"https://doi.org/10.1029/2024JC021932","url":null,"abstract":"<p>Coastal hypoxia often develops in stratified estuaries, primarily caused by the coexistence of river plume expansion and shelf seawater intrusion. Surface fronts generated by tidal plumes are associated with enhanced vertical transport. While previous studies have explored the near-bed impacts of plume fronts, the frontal processes in influencing hypoxic zones caused by the barrier layer are not straightforward. Here, we use remote sensing, shipboard, and mooring observations, aiming to explore the physical dynamics of frontal subduction for alleviating bottom hypoxia. In situ observations were conducted in the highly stratified Pearl River Estuary, a region where surface fronts frequently occur, and significant bottom hypoxia appears during summer. We show that bottom hypoxia can be temporarily alleviated by the rapid water transport driven by frontal subductions. Specifically, the critical mid-field front, trapped by tidal flow reversal, leads to the convergence in the surface layer. A downwelling process is driven by this convergence at the front, subducting surface river-born buoyant material to the bottom. Both dissolved oxygen (<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>DO</mtext>\u0000 </mrow>\u0000 <annotation> $text{DO}$</annotation>\u0000 </semantics></math>) and large particles from the river plume are transported to the bottom layer through this subduction, effectively increasing bottom <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mtext>DO</mtext>\u0000 </mrow>\u0000 <annotation> $text{DO}$</annotation>\u0000 </semantics></math> concentrations. This bottom-attached subduction, characterized by weak mixing, moves downward along the sloping isopycnals, a pathway supported by local weak stratification and weak advective forcing during the low tide. Our findings reveal a unique mechanism of the subduction at mid-field fronts, and the specific tidal conditions support this slantwise vertical transport, which further impact coastal hypoxia and particle transport.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818374","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":"Extreme Heatwave Affects the Saltwater Intrusion and River Plume Extension in the Changjiang River Estuary","authors":"Yaoting Lin,&nbsp;Yihe Wang,&nbsp;Jianrong Zhu,&nbsp;Cheng Qiu,&nbsp;Hui Wu","doi":"10.1029/2024JC022287","DOIUrl":"https://doi.org/10.1029/2024JC022287","url":null,"abstract":"<p>In 2022, China experienced an extreme hot summer accompanied by record-breaking droughts. Although extensive attentions have been paid on its influences on the urban and watershed systems, how the heatwave affects the hydrodynamics in marginal seas, which is essential for the environment and security in the coastal area, remains unclear. Here in this study, we examined effects of the heatwave on the Changjiang River Estuary and adjacent shelf seas with a numerical model. The results indicated that direct heating over the sea has dual effects on both saltwater intrusion into the estuary and river plume extension. First, strong heating causes intensified stratification, increasing the potential energy anomaly (PEA) value by approximately 7%. This weakens the vertical mixing, thus maintains a low-salinity in the surface. Second, on the contrary, extreme heating induces strong evaporation, which increases the sea surface salinity. In the estuary area, the heating-induced stratification and evaporation-induced salinization are both in favor of a stronger estuarine circulation, and therefore increase the salinity in the estuary. This worsened the already severe situation of freshwater supplement in that year. In the river plume area, the heating-induced stratification resulted a stronger plume extension, but was overwhelmed by the evaporation-induced salinization. Consequently, the plume area decreased by 8.52%. In contrast, in normal years, precipitation dominates in summer due to the heavy rainfall, and thus the co-work of heating-induced stratification and precipitation-induced freshening further enhances the plume extension. This study contributes to understanding of the interlinked effects of extreme climate events on shelf and estuarine systems.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818427","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":"Satellite-Estimation of the Global Ocean Primary Productivity via BGC-Argo Measurements","authors":"Yinxue Zhang,&nbsp;Xianqiang He,&nbsp;Yan Bai,&nbsp;Guifen Wang,&nbsp;Teng Li,&nbsp;Difeng Wang,&nbsp;Fang Gong,&nbsp;Qiankun Zhu","doi":"10.1029/2024JC021163","DOIUrl":"https://doi.org/10.1029/2024JC021163","url":null,"abstract":"<p>Monitoring the global ocean net primary productivity (NPP) has been the primary objective of satellite ocean color remote sensing since the launch of the world's first satellite ocean color sensor in 1978. However, considerable discrepancies persist in current satellite NPP estimations, and the use of limited in situ data is one of the key challenges for accurate NPP estimation. Here, a global depth-resolved NPP profile (NPP_re) data set was constructed on the basis of 10 years of biogeochemical Argo (BGC-Argo) measurements and a tuned carbon-based productivity model (BGC_CbPM). On the basis of this data set and the XGBoost machine learning model, a global oceanic NPP_re remote sensing inversion model (XGBoost_CbPM) was established for NPP estimation from Moderate Resolution Imaging Spectroradiometer (MODIS)/Aqua data. Validation with 14 independent samples revealed a coefficient of determination of 0.87 and a mean absolute percentage deviation of 12.52% between the model predictions and in situ measurements. In addition, the results obtained via the XGBoost_CbPM model suitably agreed with the in situ measurements at two time series stations, namely BATS and HOT. In particular, the time series changes in the NPP derived by the XGBoost_CbPM model at the BATS and HOT stations were better than those of the original satellite products based on the carbon-based productivity model. More importantly, as a depth-resolved model, the XGBoost_CbPM model can provide NPP profiles that are superior to those of traditional NPP models, which can be used to estimate only the water column-integrated NPP. This study underscores the significant contribution of BGC-Argo measurements in enhancing the satellite estimation of the global ocean NPP.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143818430","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":"Tracing Macroalgal-Induced Changes in Carbon Dynamics of High-Arctic Fjords Using Biomarker Fingerprinting","authors":"Biswajit Roy,&nbsp;Archana Singh,&nbsp;Manish Tiwari","doi":"10.1029/2024JC021900","DOIUrl":"https://doi.org/10.1029/2024JC021900","url":null,"abstract":"<p>Due to rising seawater temperatures and reduced sea ice extent, the coastal Arctic region is witnessing an expansion of macroalgal forests. However, changes in carbon dynamics resulting from such extensive macroalgal growth are still unknown in the high-Arctic fjords. To trace the macroalgal signatures in Arctic fjords, bulk C-isotopic and compound-specific <i>n</i>-alkane distributions were studied in dominant macroalgae (brown, red, and green) (<i>n</i> = 20) and also surface sediments (<i>n</i> = 13) from the inner to outer regions of Kongsfjorden (Svalbard). The macroalgal species shows variable C-isotopic signature (−17.0‰ to −28.9‰) but similar distribution of long-chain <i>n</i>-alkanes (&gt;<i>n</i>-C₂₃) with no predominance in carbon homologs, supporting environmental induced <i>n</i>-alkyl lipid production compared to the bulk biomass. Despite similar grain size and mineral composition of the fjord sediments, differences in C-isotopic composition and <i>n</i>-alkanes distribution indicate contribution of organic matter from different sources. In the inner and middle fjord region, the C-isotopic distribution (−23.3 ± 1.1‰ to −23.4 ± 1.3‰) and short-to long-chain <i>n</i>-alkanes signatures highlight possible mixing of contribution from phytoplankton, macroalgal-debris, and terrestrial sources. While, in the outer fjord, significantly lower δ¹³C values (−25.6 ± 0.9‰) and <i>n</i>-alkane distribution similar to macroalgal communities suggest lipid accumulation possibly sourced from the reworking of macroalgal-debris. High sedimentation and microbial breakdown of macroalgal debris create a low-oxygen environment, as evidenced by higher cyclic octasulphur compounds in the inner and middle fjord region. Under future warming conditions, such oxygen-starved regions in Arctic fjords may become more common as macroalgal forests expand and sediment influx increases.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809443","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":"Marine Mammal-Based Observations of Subsurface-Intensified Eddies in the Seasonally Sea Ice-Covered Southern Ocean","authors":"Jennifer A. Kosty,&nbsp;Ken X. Zhao,&nbsp;Andrew L. Stewart,&nbsp;Daniel E. McCoy,&nbsp;Daniele Bianchi,&nbsp;Georgy E. Manucharyan","doi":"10.1029/2024JC021781","DOIUrl":"https://doi.org/10.1029/2024JC021781","url":null,"abstract":"&lt;p&gt;Submesoscale coherent vortices (SCVs) are long-lived subsurface-intensified eddies that advect heat, salt, and biogeochemical tracers throughout the ocean. Previous observations indicate that SCVs are abundant in the Arctic because sea ice suppresses surface-intensified mesoscale structures. Regional observational and modeling studies have indicated that SCVs may be similarly prevalent beneath Antarctic sea ice, but there has been no previous systematic attempt to observe these eddies. This study presents the discovery of eddies in the Southern Ocean's seasonally sea ice-covered region using the Marine Mammals Exploring the Oceans Pole to Pole (MEOP) hydrographic measurements. Eddies are identified via a novel algorithm that utilizes anomalies in spice, isopycnal separation, and dynamic height along MEOP seal tracks. This algorithm is tested and calibrated by simulating the MEOP seal tracks using output from a 1/48&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; global ocean/sea ice model, in which subsurface eddies are independently identified via the Okubo–Weiss parameter. Approximately 60 detections of cyclonic and over 100 detections of anticyclonic SCVs are identified, with typical dynamic height anomalies of &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;mn&gt;0.05&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;msup&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mspace&gt;&lt;/mspace&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;2&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} 0.05,{mathrm{m}}^{2},{mathrm{s}}^{-2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, core depths of &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;mn&gt;200&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} 200,mathrm{m}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, and vertical half-widths of &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;mn&gt;100&lt;/mn&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;m&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${sim} 100,mathrm{m}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;, similar to their Arctic counterparts. The eddies exhibit a pronounced geographical asymmetry: cyclones are exclusively observed in the open ocean, ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021781","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143793913","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 Local Wind Stress Curl in Modulating Kuroshio Extension Latitudinal Variability","authors":"Mingshun Fan,&nbsp;Xiaohui Liu,&nbsp;Tongya Liu,&nbsp;Dake Chen","doi":"10.1029/2024JC021742","DOIUrl":"https://doi.org/10.1029/2024JC021742","url":null,"abstract":"<p>The Kuroshio Extension (KE) exhibits a typical interannual to decadal latitudinal shift. Previous studies have proposed that eastern/central North Pacific wind and oceanic intrinsic variability are responsible for the KE variability. In this study, we define a KE index using Empirical Orthogonal Function analysis based on subsurface temperature to quantify the variability of the KE shift caused by thermocline migration. The KE region exhibits positive (negative) temperature anomalies and clockwise (anti-clockwise) circulation anomalies in the north (south) phase of the KE. A lead correlation analysis indicates that, in addition to a 3–4 years leading correlation between the eastern/central North Pacific wind stress curl anomalies and the KE index, a significant linear correlation is revealed in the local region when the wind stress curl anomalies lead the KE index 0–1 year. By conducting a series of sensitivity experiments using both a global circulation model and a reduced gravity model, we suggest that both local wind and (broad) remote wind are responsible for the interannual to decadal variability of the KE, with their contributions being comparable. Regarding the local wind forcing process, when the wind stress curl anomalies are positive (negative) in the western North Pacific, they generate negative (positive) local Sea Surface Height anomalies and temperature anomalies through Ekman divergence (convergence), resulting in the southward (northward) shift of the KE.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801273","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":"Decreased Air-Sea \u0000 \u0000 \u0000 \u0000 CO\u0000 2\u0000 \u0000 \u0000 ${mathbf{text{CO}}}_{mathbf{2}}$\u0000 Flux During the Persistent Marine Heatwaves in the Yellow Sea and East China Sea","authors":"Guozhi Ren,&nbsp;Rong Na,&nbsp;Shaoqing Zhang,&nbsp;Zengrui Rong,&nbsp;Wentao Ma,&nbsp;Fei Chai,&nbsp;Yongjun Tian,&nbsp;Yang Gao,&nbsp;Lv Lu","doi":"10.1029/2024JC021525","DOIUrl":"https://doi.org/10.1029/2024JC021525","url":null,"abstract":"&lt;p&gt;Marine heatwaves (MHWs) exert a significant influence on marine ecosystem, especially in marginal seas where carbonate processes are intricately linked to temperature variations. However, how MHWs affect the carbonate processes in marginal seas, such as the Yellow Sea (YS) and East China Sea (ECS), remains unclear. Here, we employ a physical-biogeochemical model to simulate marine ecosystem, aiming to systematically quantify impacts of persistent MHWs (PMHWs) on air-sea &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; flux (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;FCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{FCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) anomaly in YS and ECS. Results reveal that due to reduced wind speed and elevated temperature during PMHWs, ocean &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; reservoir experiences dramatic decrease. In summer when the ocean releases CO&lt;sub&gt;2&lt;/sub&gt; to the atmosphere, suppressed ocean CO&lt;sub&gt;2&lt;/sub&gt; outgassing induced by decreased wind speed counteracts elevated ocean CO&lt;sub&gt;2&lt;/sub&gt; outgassing resulted from high temperature. In winter, both wind speed and temperature factors suppress ocean CO&lt;sub&gt;2&lt;/sub&gt; absorption from the atmosphere to the ocean. In addition, the spatial pattern of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;FCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{FCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; is dominated by partial pressure of &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;CO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{CO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; in the surface water (&lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mtext&gt;pCO&lt;/mtext&gt;\u0000 &lt;mn&gt;2&lt;/mn&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${text{pCO}}_{2}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;). While thermal effects have a contribution of 61% and 33% in YS and ECS to positive &lt;span&gt;&lt;/span&gt;&lt;m","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143801598","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":"On the Impact of Southeastern Pacific-Generated Storm Surges on the Southwestern Atlantic Continental Shelf: Interoceanic Connections Through Coastally Trapped Waves","authors":"Matías G. Dinapoli,&nbsp;Claudia G. Simionato","doi":"10.1029/2024JC021685","DOIUrl":"https://doi.org/10.1029/2024JC021685","url":null,"abstract":"<p>The storm surge in the Southwestern Atlantic Continental Shelf (SWACS) has been characterized as a process forced regionally by migrating atmospheric Rossby waves. When they produce alongshore winds, Ekman transport drives a sea level anomaly that then propagates northward as a Kelvin wave. Here, we explore the hypothesis that Rossby waves on the polar jet stream could generate additional surges in the southeastern Pacific by inverted barometer effect and/or Ekman transport, that then propagate to the SWACS as remotely forced signals connecting both oceans, by means of process-oriented numerical simulations. We find that atmospheric waves initially force a sea level anomaly over the South Pacific Ocean by inverted barometer effect; it increases by the action of alongshore winds when the signal interacts with the coast, and finally enters the SWACS. Remotely generated surge displays strong pseudo-periodicity in a band around 7.5 days and amplitudes of the order of 10% of the regional one. Although remotely and local forced events are independent, they can overlap originating more extreme events. Activity shows a statistically significant seasonal cycle (with mean kinetic energy in winter almost doubling that in summer) and interannual variability (with mean yearly activity almost doubling in some years) at 2–7 years that has increased since 1997, probably due to modulation of the storm tracks by climate variability. Incorporating this process in ocean simulations reduces the forecast/hindcast error of the oceanic surge by 50%.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787025","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 Wind-Driven Time-Variable Circulation in the Arctic Mediterranean","authors":"A. L. P. Sjur,&nbsp;P. E. Isachsen,&nbsp;J. Nilsson,&nbsp;J. H. LaCasce,&nbsp;M. D. Ryseth","doi":"10.1029/2024JC021713","DOIUrl":"https://doi.org/10.1029/2024JC021713","url":null,"abstract":"<p>The Arctic Ocean is a key component of Earth's climate system, and an understanding of ocean dynamics in this region is central for predicting how the Arctic is responding to a changing climate. In this study, we examine the ocean circulation in a high-resolution numerical model of the Arctic Ocean and Nordic Seas. Based on what is observed in this simulation, we reexamine an existing idealized linear model estimating the time-variable large-scale circulation in ocean basins, and test it against the highly nonlinear numerical model. The idealized model is an integral relation derived from the linear momentum equations and assumes that the circulation around a closed depth contour is driven by surface stresses and regulated by bottom friction. We show that the idealized model estimates agree very well with the numerical simulations. This indicates that much of the variability of the large-scale circulation can be explained by linear processes. In particular, a correct description of the net surface stress over partially ice-covered areas improves the correlation between linear model and numerical simulations significantly in the Arctic Ocean compared to a previous study. However, undetected in that previous study, we now find that the linear model might be lacking a cyclonic tendency.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 4","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2024JC021713","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143787026","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}