Journal of Geophysical Research-Oceans最新文献_第9页

Water Column Cycling of Cadmium in the North-Eastern and Subtropical Gyre Region of the Indian Ocean 印度洋东北和副热带环流区镉的水柱循环

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-11 DOI: 10.1029/2025JC022817

Tapas Kumar Mishra, Sunil Kumar Singh

{"title":"Water Column Cycling of Cadmium in the North-Eastern and Subtropical Gyre Region of the Indian Ocean","authors":"Tapas Kumar Mishra, Sunil Kumar Singh","doi":"10.1029/2025JC022817","DOIUrl":"10.1029/2025JC022817","url":null,"abstract":"The biogeochemical cycling of dissolved cadmium (dCd) in the ocean has been the subject of extensive research, owing to its nutrient-like behavior and resemblance to the macronutrient phosphate (PO4). In this study, 34 complete vertical profiles were collected during the cruises GI01 and GI06, meridional and zonal transects, respectively, as a part of the GEOTRACES India program from the Indian Ocean to investigate the biogeochemical cycling of dCd and PO4. The vertical profiles of dCd along the GI01 and GI06 transects show nutrient-like distribution, similar to that of the macronutrient phosphate. The N-S decreasing gradient in the surface dCd concentration suggests the combined role of riverine and atmospheric input to the Bay of Bengal (BoB), like dAl and dCo. Very low dCd content was observed in the surface waters of the oligotrophic subtropical gyre region. In the diatom-rich region of BoB, comparatively higher dCd was observed in the intermediate waters due to the regeneration of Cd-rich POC compared to the other regions. The intense oxygen minimum zone region of the BoB does not show any evidence of Cd loss from the water column through cadmium sulfide precipitation in the anoxic microenvironment. A negative Cd* (−0.25 nmol kg−1) observed at the intermediate water depth in the southern sector of the Indian Ocean marks the advection of Cd-deficient Antarctic Intermediate Water (AAIW). The overall slope obtained from Cd-PO4 cross plot in the Indian Ocean is ∼0.33 nmol μmol−1, which is well correlated with the global ocean slope of 0.35 nmol μmol−1.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814953","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}

引用次数: 0

Comparison of the Environmental Adaptation Strategies of Abundant and Rare Taxa in the Sediments of the Northwestern South China Sea 南海西北部沉积物中丰富与稀有分类群的环境适应策略比较

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-11 DOI: 10.1029/2025JC022964

Wenxue Che, Xiao Tan, Hui Zhao, Ying Man

{"title":"Comparison of the Environmental Adaptation Strategies of Abundant and Rare Taxa in the Sediments of the Northwestern South China Sea","authors":"Wenxue Che, Xiao Tan, Hui Zhao, Ying Man","doi":"10.1029/2025JC022964","DOIUrl":"10.1029/2025JC022964","url":null,"abstract":"Understanding microbial community assembly mechanisms is central to understanding ecosystem stability and environmental adaptation strategies. However, depth-dependent patterns and their driving factors in the community assembly of abundant and rare taxa in subtropical bay sediments remain poorly understood. In this study, 16S rRNA sequencing was employed to analyze sediment microbial communities across depth gradients at 10 sites in the northwestern South China Sea. The results revealed that rare bacterial communities exhibited high sensitivity to depth variation. Functional prediction revealed that rare taxa drive ecosystem multifunctionality via a broader range of diverse C/N/S transformations (including unique pathways such as lactate-to-acetate conversion and sulfur oxidation), whereas abundant taxa specialize in stable core energy metabolism (such as glycolysis and the tricarboxylic acid cycle (rTCA) cycle) and exhibit robust environmental adaptability through metabolic flexibility and strong network connectivity. Community assembly mechanisms indicated that deterministic processes dominated the assembly of rare taxa with 47%–67% contribution rates. In contrast, the abundant taxa were primarily regulated by dispersal limitation (average proportion: 57%) and drift (average proportion: 43%). Co-occurrence networks revealed strong connections between abundant and rare taxa with abundant taxa playing a critical role in maintaining ecological network stability. In conclusion, this study provides new insights into the environmental adaptation strategies of abundant and rare bacterial communities in subtropical marine sediments and establishes a theoretical framework for understanding the depth-dependent microbial dynamics in coastal ecosystems.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144814952","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}

引用次数: 0

Estuarine Sediment Dynamics Influenced by Successive Typhoons: Turbidity Maximum Zone Response and Mechanisms in the Pearl River Estuary 连续台风对河口泥沙动力学的影响：珠江口浊度最大带响应及其机制

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-09 DOI: 10.1029/2024JC022301

Mengqi Li, Nan Wang, Guangxue Li, Dehai Song, Lei Zhang, Shidong Liu, Xianwen Bao

{"title":"Estuarine Sediment Dynamics Influenced by Successive Typhoons: Turbidity Maximum Zone Response and Mechanisms in the Pearl River Estuary","authors":"Mengqi Li, Nan Wang, Guangxue Li, Dehai Song, Lei Zhang, Shidong Liu, Xianwen Bao","doi":"10.1029/2024JC022301","DOIUrl":"10.1029/2024JC022301","url":null,"abstract":"Successive typhoons, defined as two or more typhoons passing within a few days, drive cumulative atmospheric-oceanic responses; however, their effects on estuarine sediment dynamics remain understudied. In particular, for the turbidity maximum zone (TMZ)—a critical “source-sink” area for sediment transport in estuaries—the mechanisms of “destruction” and “reconstruction” during successive typhoons are still unclear. Therefore, the MIKE 21/3 coupled model was used to investigate sediment transport processes during successive typhoons Hato and Pakhar in the Pearl River Estuary. The results show that hydrodynamic conditions recovered within 50 hr, shorter than the 4-day typhoon interval—but Hato-induced sediment resuspension persisted for 10 days, resulting in the seaward sediment transport flux (STF) caused by the subsequent, weaker Pakhar being higher than that of Hato. During Hato, wind-induced resuspension became the main source of sediment in the TMZ, tripling its spatial extent through erosion (“disruption”). The subsequent Pakhar compressed the TMZ longitudinally by 7.8 km and thickened it vertically by 4.4 m through density anchoring at the salt-wedge interface (“rebuilding”). Strong winds were the main driver of STF through tidal pumping and shear effects, contributing more than 60%. The differential dynamics of “rapid hydrologic response and recovery” versus “delayed sediment response and recovery” triggered by successive typhoons enable weaker subsequent typhoons to significantly alter depositional mechanisms through the residual suspended sediment effect. This necessitates a reconceptualization of the timescale and intensity thresholds of successive typhoons affecting estuarine sediments.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129010","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}

引用次数: 0

Tidal Effects on Antarctic Bottom Water Formation in a Changing Climate 气候变化中潮汐对南极底水形成的影响

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-09 DOI: 10.1029/2025JC022443

Xianxian Han, Andrew Stewart, Zhaomin Wang, Qinghua Yang, Chengyan Liu, Dake Chen

{"title":"Tidal Effects on Antarctic Bottom Water Formation in a Changing Climate","authors":"Xianxian Han, Andrew Stewart, Zhaomin Wang, Qinghua Yang, Chengyan Liu, Dake Chen","doi":"10.1029/2025JC022443","DOIUrl":"10.1029/2025JC022443","url":null,"abstract":"Antarctic bottom water (AABW) forms through the descent of dense shelf waters (DSW) into the abyssal ocean, with tides playing a key role in DSW transport and entrainment. Previous studies suggest that tides can suppress the net overflow entrainment, favoring the formation of denser AABW. However, how tidal effects on AABW formation and associated material sequestration vary with a changing climate remains unclear. In this study, an idealized numerical model is used to investigate potential climatic influences on tidally influenced AABW properties. Experiments are conducted with varying ambient stratifications and rates of DSW supply, inspired by projected future changes over the Antarctic continental shelf. The results show that tidal advection and associated V-shaped front can modify the vertical diffusivity and the exchanges between DSW and its ambient waters, thereby altering the properties of AABW. For a future warm and salty shelf, AABW will become warmer and saltier accordingly, with the effects of the V-shaped front weakening significantly. Conversely, for a future cold and fresh shelf, AABW formation is nearly nonexistent due to the stronger dilution of DSW, and the tidal effects become much weaker. Additionally, tidal suppression of overflow mixing is only significant for large DSW fluxes (thickness) and becomes negligible for small DSW fluxes. These findings suggest that the contribution of tides to DSW descent will weaken under global warming, thereby accelerating the slowdown of AABW formation.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129009","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}

引用次数: 0

Contrasting Trends in Phytoplankton Diversity, Size Structure, and Carbon Burial Efficiency in the Mediterranean Sea Under Shifting Environmental Conditions 变化环境条件下地中海浮游植物多样性、大小结构和碳埋藏效率的对比趋势

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-09 DOI: 10.1029/2025JC022486

Camille Godbillot, Baptiste Pesenti, Karine Leblanc, Luc Beaufort, Cristele Chevalier, Julien Di Pane, Xavier Durrieu de Madron, Thibault de Garidel-Thoron

{"title":"Contrasting Trends in Phytoplankton Diversity, Size Structure, and Carbon Burial Efficiency in the Mediterranean Sea Under Shifting Environmental Conditions","authors":"Camille Godbillot, Baptiste Pesenti, Karine Leblanc, Luc Beaufort, Cristele Chevalier, Julien Di Pane, Xavier Durrieu de Madron, Thibault de Garidel-Thoron","doi":"10.1029/2025JC022486","DOIUrl":"10.1029/2025JC022486","url":null,"abstract":"Shifts in the phytoplankton assemblage induced by environmental changes have significant implications for carbon cycling and marine food webs, but remain poorly constrained across spatiotemporal scales. Here, we investigate the effects of rising sea surface temperatures and increased stratification on the phytoplankton composition and size in the northwestern Mediterranean Sea (2010–2019) using two sediment trap series: one in the oligotrophic Ligurian Sea and the other in the deep convection zone of the Gulf of Lion. We apply deep learning image analysis to quantify phytoplankton particle fluxes, size distributions, and relative assemblages, focusing on coccolithophores, diatoms, and silicoflagellates. Our results show a general decline of phytoplankton fluxes to the seafloor, mirroring the decrease in vertical mixing in the water column. Both sites show a shift toward phytoplankton species adapted to stratified and nutrient-depleted conditions, although with contrasting patterns. In the Ligurian Sea, deep-dwelling coccolithophore species become dominant, while in the Gulf of Lion, summer-associated siliceous species, including large diatoms and silicoflagellates, show an increase. These contrasted trends, which likely result from differences in nutrient inputs and pH changes in the surface between the two sites, have implications for the efficiency of carbon export pathways at depth. Specifically, the increasing dominance of smaller phytoplankton in the Ligurian Sea leads to a reduction in carbon burial efficiency, while in the Gulf of Lion, the enhanced contribution of larger diatoms may sustain higher export and burial rates in the future.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022486","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129011","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}

引用次数: 0

Meso- and Submesoscale Circulation Origins for Subsurface Oxygen Intrusions Into the Oxygen Deficient Zone of the Eastern Tropical North Pacific 北太平洋东部热带缺氧带地下氧侵入的中尺度和亚中尺度环流来源

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-08 DOI: 10.1029/2025JC022577

A. Pietri, M. Altabet, G. W. Cowles, E. D’Asaro

{"title":"Meso- and Submesoscale Circulation Origins for Subsurface Oxygen Intrusions Into the Oxygen Deficient Zone of the Eastern Tropical North Pacific","authors":"A. Pietri, M. Altabet, G. W. Cowles, E. D’Asaro","doi":"10.1029/2025JC022577","DOIUrl":"10.1029/2025JC022577","url":null,"abstract":"Subsurface oxygen maxima (SOM) are recurrent but poorly understood features within the eastern tropical North Pacific oxygen deficient zone (ODZ). Here, we analyze a subsurface oxygen maximum (SOM) observed during the SR2114 cruise using in situ biogeochemical and physical measurements, satellite remote sensing, and Lagrangian particle tracking. The SOM was detected around the 26.4 isopycnal (∼150–200 m) and spatially associated with elevated oxygen concentrations within an otherwise hypoxic environment. Our results show that intense gap winds in the Gulfs of Tehuantepec and Papagayo generate strong upwelling, vertical mixing, and horizontal advection near the coast, potentially allowing subsurface layers to come into contact with surface waters and become oxygenated. The observed vertical penetration of wind-driven features below the Ekman layer also suggests the influence of eddy-wind interactions that reinforce vertical coherence and enhance the offshore transport of oxygen-rich waters. The offshoreward jets observed down to the SOM layer depth highlight the contribution of such coupled processes to ventilating the ODZ interior. Furthermore, float-based observations along isopycnals indicate progressive oxygen loss over time, likely due to local respiration, pointing to dynamic interplay between physical supply and biogeochemical consumption. Together, these findings underscore the pivotal role of coastal wind forcing and mesoscale dynamics in shaping the subsurface oxygen landscape of the eastern tropical North Pacific. The Lagrangian analysis also highlights distinct pathways for water parcels within the ODZ: south of 14°N, water masses are primarily influenced by equatorial currents, whereas in the northern region, water parcels predominantly originate from coastal sources with extended residency times.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022577","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145128968","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}

引用次数: 0

Net Community Production Variability in Response to Changing Upwelling Intensity Before and After a Typhoon in the Southern East China Sea 台风前后东海净群落生产变率对上升流强度变化的响应

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-06 DOI: 10.1029/2025JC022770

Kai-Jung Kao, Wei-Jen Huang, Yonghui Gao, Hsiao-Chun Tseng, Veran Weerathunga, Fei-Ling Yuan, Gwo-Ching Gong, Wen-Chen Chou

{"title":"Net Community Production Variability in Response to Changing Upwelling Intensity Before and After a Typhoon in the Southern East China Sea","authors":"Kai-Jung Kao, Wei-Jen Huang, Yonghui Gao, Hsiao-Chun Tseng, Veran Weerathunga, Fei-Ling Yuan, Gwo-Ching Gong, Wen-Chen Chou","doi":"10.1029/2025JC022770","DOIUrl":"10.1029/2025JC022770","url":null,"abstract":"Continental shelves contribute approximately 30% of the ocean's net community production (NCP), significantly influencing the global oceanic carbon cycle. However, the regulation of NCP variability on continental shelves by physical processes, such as upwelling remains poorly understood. High spatial resolution mixed-layer O2/Ar-NCP measurements were conducted using equilibrator inlet mass spectrometry in the southern East China Sea (ECS) before (6–9 July 2018) and after (13–17 July 2018) Typhoon “Maria.” The relationship between biological N2O and O2 in the water column was used to correct for the impact of upwelling and vertical mixing on O2/Ar-NCP measurements (refined NCP, RNCP). Our study revealed that the periodic upwelling in the southern ECS relaxed before the typhoon and intensified afterward. This change in upwelling conditions corresponded to an increase in RNCP at the southern ECS from an average of 17 ± 11 mmol C m−2 d−1 to 99 ± 25 mmol C m−2 d−1. The N2O-based correction improved the estimation of O2/Ar-NCP measurements in upwelling regions. Without this correction, NCP values were underestimated, with the degree of underestimation increasing from 18 ± 9 to 80 ± 17 mmol C m−2 d−1 as upwelling intensified during our study period. We suggest that the upwelling regions within the mixed layer were net autotrophic before and after the typhoon, yielding valuable information for refining fishery models.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022770","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144782457","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}

引用次数: 0

Sequential Evolution of Changjiang Diluted Water and Its Impact on Stratification and Phytoplankton Blooms in the East China Sea During Summer 2020 2020年夏季长江稀释水序列演化及其对东海分层和浮游植物华度的影响

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-06 DOI: 10.1029/2025JC022655

Seung-Woo Lee, Dabin Lee, Suyun Noh, Go-Un Kim, Sung-Hwan Park, Jin-Yong Jeong, Howon Lee, Jae Hoon Noh, Jongmin Jeong, Jaeik Lee, Yongchim Min, Su-Chan Lee, In-Ki Min, Jin-Yong Choi

{"title":"Sequential Evolution of Changjiang Diluted Water and Its Impact on Stratification and Phytoplankton Blooms in the East China Sea During Summer 2020","authors":"Seung-Woo Lee, Dabin Lee, Suyun Noh, Go-Un Kim, Sung-Hwan Park, Jin-Yong Jeong, Howon Lee, Jae Hoon Noh, Jongmin Jeong, Jaeik Lee, Yongchim Min, Su-Chan Lee, In-Ki Min, Jin-Yong Choi","doi":"10.1029/2025JC022655","DOIUrl":"10.1029/2025JC022655","url":null,"abstract":"The Changjiang Diluted Water (CDW) plays a crucial role in shaping the hydrography and ecosystem dynamics of the East China Sea (ECS), particularly during summer when freshwater discharge enhances stratification and modulates biogeochemical processes. Despite its importance, the detailed progression of CDW and its short-term impacts remain poorly understood due to the limited availability of high-resolution observations. Using high-resolution in situ observations from the Ieodo Ocean Research Station in summer 2020, we examined the sequential evolution of CDW and its effects on the upper-ocean structure and phytoplankton blooms. CDW evolution was categorized into six distinct phases, characterized by abrupt shifts in salinity and stratification, driven by monsoonal winds, tides, and typhoon-induced mixing. CDW intrusion formed a persistent barrier layer that suppressed vertical mixing and trapped surface heat, leading to increased sea surface temperatures. Nutrient influx from CDW, enriched in nitrate and phosphate, promoted the proliferation of diatoms relative to picoplankton and dinoflagellates, although all groups increased during the CDW-influenced period. Internal wave-induced mixing facilitated nutrient replenishment from deeper layers, partially alleviating phosphate deficiency inherent in CDW and enhancing phytoplankton productivity. Typhoon Bavi disrupted stratification through strong vertical mixing, resulting in a high-salinity state that differed from preintrusion hydrography. This study provides a time-resolved view of CDW-driven variability and demonstrates how episodic freshwater inputs, coupled with physical forcing, regulate stratification, nutrient supply, and ecosystem response in the ECS.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1029/2025JC022655","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144782706","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}

引用次数: 0

An Idealized Model for the Emergence of the North Icelandic Jet 冰岛北部喷流出现的理想模型

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-06 DOI: 10.1029/2024JC021992

T. Ø. Moe, K. Daae, K. Våge, S. Semper

{"title":"An Idealized Model for the Emergence of the North Icelandic Jet","authors":"T. Ø. Moe, K. Daae, K. Våge, S. Semper","doi":"10.1029/2024JC021992","DOIUrl":"10.1029/2024JC021992","url":null,"abstract":"The North Icelandic Jet (NIJ) is a significant contributor to the lower limb of the Atlantic Meridional Overturning Circulation, transporting dense overflow waters banked up along the slope north of Iceland equatorward and supplying up to half of the Denmark Strait overflow water, including the densest portion. Major uncertainties remain regarding what mechanisms contribute to the emergence of the NIJ northeast of Iceland. This study investigates previously proposed mechanisms using a novel setup with a high-resolution idealized model for the north Icelandic slope. We set up a channel model along the slope north of Iceland with differing slope geometry, no external forcing, and horizontally uniform initial and boundary conditions based on observations. We impose highly idealized inflows and outflows as boundary conditions in the west, emulating the North Icelandic Irminger Current (NIIC) inflow and dense NIJ outflow through Denmark Strait. The model consistently replicates key features of the NIJ, such as its mid-depth intensified core associated with diverging isopycnals away from the slope. Our results corroborate that a steeper slope, a stronger NIIC-like current, and stronger cross-slope density gradients promote instabilities closely related to the emerging NIJ-like current. Moreover, the simulated gradual eastward weakening of the NIJ-like current combined with enhanced eddy kinetic energy in the east is sufficient to facilitate an emergence. The variability of the model's NIJ-like current is largely associated with passing eddies, which might explain some of the observed occupations where the NIJ features a double-core structure.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144782707","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}

引用次数: 0

Effect of Climate Change-Induced Tropical Cyclone Track Shift on Sedimentology in the East China Coastal Ocean 气候变化引起的热带气旋路径转移对华东沿海海洋沉积学的影响

IF 3.4 2区地球科学

Journal of Geophysical Research-Oceans Pub Date : 2025-08-05 DOI: 10.1029/2024JC022245

Chaoran Xu, Yang Yang, Mingxiao Xie, Jeremy D. Bricker, Fan Zhang, Ya Ping Wang, Xiaoliang Xia, Jianjun Jia

{"title":"Effect of Climate Change-Induced Tropical Cyclone Track Shift on Sedimentology in the East China Coastal Ocean","authors":"Chaoran Xu, Yang Yang, Mingxiao Xie, Jeremy D. Bricker, Fan Zhang, Ya Ping Wang, Xiaoliang Xia, Jianjun Jia","doi":"10.1029/2024JC022245","DOIUrl":"10.1029/2024JC022245","url":null,"abstract":"Tropical cyclones (TCs) significantly influence coastal sedimentation, geomorphologic features, and morphodynamic processes through strong winds, heavy rains, and storm surges. These effects are particularly pronounced in the east China coastal ocean. However, the impacts of poleward and landward shifts in TC tracks on sedimentology, specifically sediment transport and erosion-deposition processes, remain insufficiently understood. This study utilizes the Delft3D-FM numerical model integrated with TC best track data and field measurements to investigate sediment transport patterns under historical TC tracks and to quantify erosion responses to poleward and landward track shifts. From the historical sediment transport pattern derived from the typical historical TC track, results reveal that sediment in waters shallower than 30 m is highly sensitive to TC activity, with four distinct zones where net sediment transport is sensitive to the change of typical historical TC tracks. Coastal erosion depth changes due to poleward and landward shifts of typical TC tracks during the peak TC intensity period are quantified as 0.24–1.63 cm°N−1 and 0.05–1.06 cm°E−1, respectively. Under global warming scenarios, these values are projected to increase by 2.45%–8.00% and 4.71%–13.33%, respectively. Identifying the coastal areas more susceptible to TC-induced sediment transport and quantitatively assessing the effects of poleward and landward track shifts are important for understanding local TC variability and supporting research on sedimentology during TCs and the future protection of coastal areas.","PeriodicalId":54340,"journal":{"name":"Journal of Geophysical Research-Oceans","volume":"130 8","pages":""},"PeriodicalIF":3.4,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144773712","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}

引用次数: 0