Journal of Geophysical Research-Oceans最新文献

{"title":"Microbial Respiration Across Subtropical Eddies: Submesoscale Variability and Biogeochemical Drivers","authors":"J. L. García,&nbsp;M. F. Montero,&nbsp;X. A. Álvarez-Salgado,&nbsp;J. Arístegui","doi":"10.1029/2026JC024036","DOIUrl":"https://doi.org/10.1029/2026JC024036","url":null,"abstract":"<p>Island-induced eddies from the Canary Islands region propagate southwestward along the Canary Eddy Corridor, exporting biological and biogeochemical properties to the oligotrophic open ocean. However, their contribution to organic matter remineralization, and consequently to the biological carbon pump, throughout their life cycle remains poorly understood. Using respiratory electron transport system (ETS) activity as a proxy for microbial respiration, we investigated two cyclonic and two anticyclonic eddies at different stages of development and found distinct respiration patterns. Epipelagic respiration peaked in the most intense cyclonic eddy, whereas mesopelagic respiration showed localized maxima beneath most eddies and tended to be higher in cyclonic than in anticyclonic eddies. At submesoscale resolution, plume-like ETS structures emerged within the mesopelagic layer, modulating respiration variability across eddies. Mesopelagic respiration variability was driven primarily by suspended particulate organic matter, whereas dissolved organic matter and its chromophoric and fluorescent protein-like fractions contributing less. This contrasts with the greater contribution of dissolved organic matter to apparent oxygen utilization. Notably, fluorescent humic-like substances were negatively correlated with respiration, indicating reduced microbial activity in older water masses. These findings demonstrate that mesoscale eddies can strongly regulate microbial organic matter remineralization and, consequently, influence ocean carbon cycling.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC024036","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068206","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 18.6-Year Lunar Nodal Cycle in Internal Tides","authors":"Zhongxiang Zhao,&nbsp;Chenxuan Ji,&nbsp;J. A. Mattias Green,&nbsp;Richard Ray","doi":"10.1029/2026JC024284","DOIUrl":"https://doi.org/10.1029/2026JC024284","url":null,"abstract":"<p>Both the 18.6-year lunar nodal cycle (LNC) and long-term quasi-linear trends in oceanic internal tides are detected using 30 years of satellite altimeter data (1993–2022). The data are divided into 28 overlapping equal-sized subsets, from which 28 sets of global internal tide fields are constructed for mode-1 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>K</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{K}}_{1}$</annotation>\u0000 </semantics></math>, <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{O}}_{1}$</annotation>\u0000 </semantics></math>, and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{M}}_{2}$</annotation>\u0000 </semantics></math> constituents. Their global-mean amplitude and phase time series demonstrate that the detected LNC is consistent with the equilibrium theory. The detected quasi-linear trends are evidently the anticipated consequence of the increasingly stratified ocean caused by global warming. The global distribution of internal tidal energy is significantly modulated by the 18.6-year LNC, because (a) <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>K</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{K}}_{1}$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>O</mi>\u0000 <mn>1</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{O}}_{1}$</annotation>\u0000 </semantics></math> are 180<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math> out of phase with <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <msub>\u0000 <mi>M</mi>\u0000 <mn>2</mn>\u0000 </msub>\u0000 </mrow>\u0000 <annotation> ${mathrm{M}}_{2}$</annotation>\u0000 </semantics></math> in the cycle, and (b) the diurnal and semidiurnal constituents have different spatial patterns. We suggest that the nodal modulation of internal tides may affect internal tide-driven ocean mixing and thus large-scale ocean circulations.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068204","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 Transformation of Trace Metal Distributions Across the Mackenzie Shelf and Through the Northwest Passage","authors":"Tia K. Anderlini,&nbsp;Jean-Éric Tremblay,&nbsp;Jay T. Cullen","doi":"10.1029/2026JC024398","DOIUrl":"https://doi.org/10.1029/2026JC024398","url":null,"abstract":"<p>Understanding the distributions of trace elements, like iron (Fe), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), lead (Pb), barium (Ba), and vanadium (V) in the Arctic Ocean is motivated in part because they can modulate key biogeochemical rate processes as micronutrients and/or toxins for primary producers, and can serve as water-mass tracers, revealing modification of Atlantic and Pacific endmembers during Arctic transit. Dissolved trace metal concentrations were measured in seawater in 2021 from the shelf of the Mackenzie River Delta and through the Northwest Passage of the Canadian Arctic Archipelago (CAA). A four-dimensional linear mixing model, using salinity, Ba concentrations, and Arctic nitrate-phosphate (ANP) endmembers, was applied to determine water mass distributions. This approach identifies sources and sinks of trace metals as waters move from the western Arctic through the Northwest Passage toward Baffin Bay, with implications for Arctic ecosystems and the properties of waters exported to the North Atlantic. Nutrient-rich Pacific waters entering the western Arctic are modified by sedimentary inputs with transit over the Chukchi shelf. In particular, elevated Cd and Zn in upper halocline waters extend from the Chukchi shelf into the coastal Beaufort Sea, Mackenzie shelf, and Amundsen Gulf. During transit, waters are further modified by inputs from the Mackenzie River (Mn, Co, Ni, Cu), sea ice melt (Mn, Co, Fe, Cu), sediment resuspension on the Mackenzie Shelf (Fe, Pb) and riverine Cu inputs within the CAA.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC024398","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068132","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":"Depth-Resolved Surfzone Wave and Roller Transformation","authors":"Jinshi Chen,&nbsp;Britt Raubenheimer,&nbsp;Steve Elgar","doi":"10.1029/2026JC024082","DOIUrl":"https://doi.org/10.1029/2026JC024082","url":null,"abstract":"<p>The vertical structures of cross-shore wave, roller, and other momentum forcing terms are examined using a two-phase Reynolds-averaged Navier-Stokes model driven with field and laboratory measured waves and bathymetry. Modeled wave height, setup, and undertow agree well with field observations along a cross-shore transect extending from the shoreline to about 5-m water depth, and with measurements in a wave flume. Momentum flux carried by wave, roller, vertical turbulence transfer, pressure slope, and vertical inertia primarily balance near the surface, while wave, vertical turbulence transfer, vertical inertia, and setup primarily balance in the mid-to lower-water column. Turbulence transports momentum downward, while vertical inertia transfers momentum upwards. Combined wave and roller forcing agrees with a linear wave theory parametrization offshore of the sandbar and on a near-planar beach, and combined wave, roller, and vertical inertia agrees with linear theory onshore of the sandbar. Roller thickness is related to local wave height, similar to previous studies. Sub-surface offshore-directed mean currents (undertow) can be estimated from the mid-to lower-water column momentum balance. Turbulence production dominates the near-surface turbulence-energy-flux balance, and its penetration depth in the sandbar trough is correlated with local wave height.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 10","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC024082","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149068199","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":"Projected Future Changes of Australian Boundary Currents—Insights From Dynamical Downscaling Simulations","authors":"Yi Jin,&nbsp;Xuebin Zhang,&nbsp;Ming Feng,&nbsp;Yucheng Lin","doi":"10.1029/2026JC024251","DOIUrl":"https://doi.org/10.1029/2026JC024251","url":null,"abstract":"<p>Australian boundary currents strongly influence regional circulation, ecosystems, and coastal environments, yet remain inadequately resolved in coarse-resolution global climate models, especially along mid-latitude coasts. To assess their future evolution, we examine boundary-current changes under an intermediate-emissions scenario with a 1/12° regional ocean model forced by ensemble-mean climate-change signals from Coupled Model Intercomparison Project Phases 6 (CMIP6), using the Australian Regional Ocean Downscaling (AUSROD) framework. The model realistically simulates the East Australian Current (EAC) and its extension, Leeuwin Current (LC), South Australian Current (SAC), and Flinders Current (FC) during 1993–2023, in close agreement with reanalysis and observations. Projections show a slight weakening of the EAC and a marked strengthening of its extension, consistent with enhanced positive wind-stress curl over the South Pacific south of ∼30°S. LC weakening, associated with a reduced meridional sea-level gradient, is primarily driven by intensified subsurface thermosteric expansion linked to Subantarctic Mode Water warming. Along southern Australia, the FC strengthens consistent with Sverdrup Balance response, while the SAC weakens in the west due to the reduced LC but shows little change in the east under intensified local westerlies. While the tendencies align with coarse-resolution CMIP6 ensemble results, the downscaled projections resolve substantially finer spatial and vertical structures. This study provides a systematic, dynamically consistent projection of Australian boundary currents at the end of the 21st century and highlights the added value of dynamical downscaling for resolving coastal and shelf processes. The AUSROD framework is practical for application to other regions, offering reliable information for future adaptation.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC024251","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048446","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":"Climatological Pathway of Agulhas Leakage: Fluxes and Transformations Through the Cape Basin","authors":"Rachel Sampson,&nbsp;Lisa Beal,&nbsp;Guillaume Novelli,&nbsp;Kathleen Donohue","doi":"10.1029/2026JC024329","DOIUrl":"https://doi.org/10.1029/2026JC024329","url":null,"abstract":"&lt;p&gt;Agulhas Leakage provides a major return pathway through which warm, salty Indian Ocean waters enter the South Atlantic (SA), influencing the Atlantic Meridional Overturning Circulation (AMOC). Quantifying its volume, heat, and salt fluxes is challenging because leakage occurs within a highly turbulent region where Agulhas waters mix with cooler, fresher South Atlantic waters. Using a 20-year Argo climatology (2002–2022), we identify a persistent Leakage Pathway connecting the Agulhas Current (AC) to the South Atlantic and quantify water-mass transformations along it. Strong lateral mixing between the Agulhas Retroflection and the Good Hope Line substantially cools (&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;0.02&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${-}0.02$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; PW) and freshens &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mfenced&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mo&gt;−&lt;/mo&gt;\u0000 &lt;mn&gt;2.2&lt;/mn&gt;\u0000 &lt;mo&gt;×&lt;/mo&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;13&lt;/mn&gt;\u0000 &lt;/msup&gt;\u0000 &lt;mspace&gt;&lt;/mspace&gt;\u0000 &lt;mi&gt;k&lt;/mi&gt;\u0000 &lt;mi&gt;g&lt;/mi&gt;\u0000 &lt;mo&gt;/&lt;/mo&gt;\u0000 &lt;mi&gt;y&lt;/mi&gt;\u0000 &lt;mi&gt;e&lt;/mi&gt;\u0000 &lt;mi&gt;a&lt;/mi&gt;\u0000 &lt;mi&gt;r&lt;/mi&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;/mfenced&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $left(-2.2times 1{0}^{13},mathrm{k}mathrm{g}/mathrm{y}mathrm{e}mathrm{a}mathrm{r}right)$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; central and intermediate waters. As a result, the total transport along the Leakage Pathway (above &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mi&gt;γ&lt;/mi&gt;\u0000 &lt;mo&gt;=&lt;/mo&gt;\u0000 &lt;mn&gt;27.92&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $gamma =27.92$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;) is &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;24.5&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;2.8&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $24.5pm 2.8$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; Sv, carrying &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantics&gt;\u0000 &lt;mrow&gt;\u0000 &lt;mn&gt;0.27&lt;/mn&gt;\u0000 &lt;mo&gt;±&lt;/mo&gt;\u0000 &lt;mn&gt;0.05&lt;/mn&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; $0.27pm 0.05$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt; PW and &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;semantic","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2026JC024329","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048539","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":"Does the Evolution of Indian Ocean Acidification Follow CMIP6 Projections Under a High-Emission Scenario?","authors":"Prasanna Kanti Ghoshal,&nbsp;A. P. Joshi,&nbsp;Kunal Chakraborty","doi":"10.1029/2026JC024515","DOIUrl":"https://doi.org/10.1029/2026JC024515","url":null,"abstract":"&lt;p&gt;The Indian Ocean (IO) surface acidification is governed by pronounced regional variability that is inadequately resolved in coarse-resolution CMIP6 models. Here, we employ eddy-resolving, dynamically downscaled outputs from three CMIP6 Earth System Models under the high-emissions SSP5-8.5 scenario to project future changes in IO acidification, with the model ensemble selected to account for uncertainty in future projections. Eddy-resolving simulations improve representation of mesoscale-driven surface acidification variability by ∼5%–10% relative to CMIP6 models, particularly in coastal regions, while reducing inter-model spatio-temporal heterogeneity. The analysis indicates a relatively weaker mean increase in [&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;H&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{H}}^{+}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;] compared with CMIP6 projections. The downscaled models yield a dynamically consistent, improved representation of the seasonal cycle of [&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;H&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{H}}^{+}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;] compared to CMIP6 models, particularly in the northern IO. This facilitates a more robust assessment of future anthropogenically driven changes in [&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;H&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{H}}^{+}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;] amplitude, with the monthly composite amplitude projected to increase by ∼63%–83% during the far-future period (FF; 2071–2100) across the IO. However, in the Arabian Sea, the increase is ∼37% smaller than in CMIP6, whereas other regions exhibit largely comparable changes. This amplification is primarily driven by enhanced sensitivity of [&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;H&lt;/mi&gt;\u0000 &lt;mo&gt;+&lt;/mo&gt;\u0000 &lt;/msup&gt;\u0000 &lt;/mrow&gt;\u0000 &lt;annotation&gt; ${mathrm{H}}^{+}$&lt;/annotation&gt;\u0000 &lt;/semantics&gt;&lt;/math&gt;] to surface temperature and dissolved inorganic carbon under warming and increased &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; uptake. Consistent with these changes, acidification extremes intensify (∼26%–45%) ","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048278","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":"Atlantic Multidecadal Oscillation and Solar Forcing Modulate Decadal-Scale Variability in Northwest Pacific Tropical Cyclone Precipitation","authors":"Yuchen Shi,&nbsp;Wei Jiang,&nbsp;Yangyang Yong,&nbsp;Tingwu Gu,&nbsp;Caifeng Liu,&nbsp;Siqi Du,&nbsp;Yuyan Jiang,&nbsp;Ting Yang,&nbsp;Hui Ouyang,&nbsp;Kefu Yu","doi":"10.1029/2026JC024472","DOIUrl":"https://doi.org/10.1029/2026JC024472","url":null,"abstract":"<p>Extreme precipitation associated with tropical cyclones (TCs) poses a growing threat to coastal communities, yet short instrumental records hamper the assessment of long-term variability. Here, we address this gap by developing a quantitative proxy for TC precipitation using a previously published, monthly resolved coral oxygen isotope (δ¹⁸O) record. This record was derived from a single <i>Porites</i> coral specimen collected offshore southern Taiwan, a region within the most active TC zone of the Northwest Pacific. Because coral δ¹⁸O reflects both sea surface temperature and seawater δ¹⁸O, we infer TC precipitation from the hydrological and isotopic imprint of isotopically depleted freshwater input recorded by the coral. Calibrated against modern data (1998–2012 CE), the proxy identified extreme TC events with a detection rate of ∼78%. We reconstructed a coral-based index of TC precipitation variability for 1906–2012 CE. We then characterized the low-frequency variability of the reconstructed index using spectral analysis and evaluated its associations with major climate drivers using correlation analyses. The 106-year record revealed pronounced interdecadal variability primarily modulated by the Atlantic Multidecadal Oscillation and solar forcing, while the influences of El Niño–Southern Oscillation and Pacific Decadal Oscillation were non-stationary, becoming more coherent after the 1950s. Our reconstruction constrains pre-instrumental TC hydroclimate variability and its drivers, informing future projections and coastal risk assessment under continued warming.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048444","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":"Environmental Controls on Eddy-Induced Chlorophyll-a Anomalies in the East Australian Current System","authors":"Jiongqiu Ren,&nbsp;Christina Schallenberg,&nbsp;Tyler Rohr,&nbsp;Peter G. Strutton,&nbsp;Moninya Roughan","doi":"10.1029/2025JC023613","DOIUrl":"https://doi.org/10.1029/2025JC023613","url":null,"abstract":"<p>Mesoscale eddies in the East Australian Current (EAC) system modulate phytoplankton growth via different mechanisms. Long-term averages of elevated and suppressed chlorophyll-a in cyclonic and anticyclonic eddies have been attributed to eddy trapping and pumping, but their seasonal variability remains less understood. Using 19 years (2003–2021) of satellite altimetry and chlorophyll-a with in situ climatologies, we show that seasonal changes in the magnitude and sign of eddy-induced chlorophyll-a anomalies are influenced by background light availability, nutrient supply, and stratification. We identify three EAC sub-regions with contrasting environments, each exhibiting distinct seasonal cycles of chlorophyll-a anomalies. In the core EAC, during a light limited, weakly stratified period (May–October), eddy-induced mixed layer depth (MLD) modulation is the dominant driver of chlorophyll-a anomalies. Cyclones enhance chlorophyll-a, while anticyclones suppress it, with anomaly magnitude increasing with eddy amplitude. In the northern Tasman Sea, during the nitrate limited period (February–June), MLD modulation also dominates, but produces opposite effects, with chlorophyll-a elevated in anticyclones and reduced in cyclones. Eddy trapping and pumping are active mainly at early lifecycle stages, whereas MLD modulation dominates as eddies mature. Our results show that chlorophyll-a concentrations in the EAC system are governed by the interplay between background conditions and time-evolving eddy physics, providing a basis for predicting eddy impacts under climate-driven shifts in background conditions.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023613","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048108","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":"Systematic Ocean Ventilation Biases in Climate Models Indicated by Chlorofluorocarbon-12","authors":"Haichao Guo,&nbsp;Toste Tanhua,&nbsp;Ivy Frenger,&nbsp;Lavinia Patara,&nbsp;Paul Spence,&nbsp;Ruijian Gou,&nbsp;Lixin Wu,&nbsp;Xuenan Li,&nbsp;Andreas Oschlies","doi":"10.1029/2025JC023718","DOIUrl":"https://doi.org/10.1029/2025JC023718","url":null,"abstract":"<p>An accurate representation of ocean ventilation in models is crucial for simulating ocean uptake of heat and carbon, as well as the ocean's supply of oxygen. Using the Inverse Gaussian Transit Time Distribution technique, we assessed ocean ventilation in current climate models via comparing water ages —defined as the time since last contact with the sea surface— derived from observed and simulated distributions of chlorofluorocarbon-12. Our analysis covers 22 climate models, including 10 coarse-resolution atmosphere-ocean coupled models (<i>COUPLED</i>, with horizontal resolution of ∼1<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math>), 8 coarse-resolution forced ocean-only models (Ocean Model Intercomparison Project), and 2 high-resolution eddy-rich models (with horizontal resolution of 0.1<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math>). We identify systematic ventilation biases consistent across most climate models: (a) the deep layer of Subantarctic Mode Water (SAMW, ∼800 m in the South Atlantic) is too old, indicating excessive isolation from the atmosphere; (b) the upper North Atlantic Deep Water (NADW, ∼2,500 m) is too young, whereas the lower NADW (&gt;4,000 m) is too old; and (c) the Antarctic Bottom Water (AABW, &gt;4000 m south of 50<span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mo>°</mo>\u0000 </mrow>\u0000 <annotation> ${}^{circ}$</annotation>\u0000 </semantics></math>S) is too old. <i>OMIP</i> models using reanalyzed atmospheric forcings show similar biases to <i>COUPLED</i> models, except for a slightly better ventilated AABW. Increasing horizontal resolution reduces global ocean ventilation biases — particularly in the AABW — thereby enhancing deep-ocean oxygen supply and increasing anthropogenic carbon storage, which in turn promotes longer-term carbon sequestration.</p>","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"131 9","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC023718","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149048107","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}