Continental Shelf Research最新文献

{"title":"Molecular composition characteristics of marine Synechococcus reflect the highly environmental heterogeneity in the shelf seas","authors":"Jialin Li ,&nbsp;Feng Shi ,&nbsp;Huiwang Gao ,&nbsp;Song Qin","doi":"10.1016/j.csr.2025.105495","DOIUrl":"10.1016/j.csr.2025.105495","url":null,"abstract":"<div><div><em>Synechococcus</em>, a dominant group of marine photosynthetic picophytoplankton, play a crucial role in primary productivity and carbon cycling within shelf seas. Its distribution patterns are highly sensitive to environmental changes, rendering it a valuable indicator for assessing ecosystem responses to both climate change and anthropogenic pressures. Nonetheless, the relationships between the genetic diversity of <em>Synechococcus</em> and environmental heterogeneity in the Bohai Sea and Yellow Sea have not been thoroughly explored. Here, we employed the high-throughput sequencing method to investigate the phylogenetic and phenogenetic diversity of <em>Synechococcus</em> in the Bohai and Yellow seas, revealing distinct genotype compositions depending on typical habitats. Regarding phylogenetic distribution, both S5.1 clades I and VI dominated in the Bohai Sea with an average proportion of 25.47 % and 26.20 %, respectively; while clades I and II became predominant in the Yellow Sea accounting for 47.72 % and 14.82 %, respectively. Phenogenetically, type 2 dominated in the Bohai Sea occupying 53.15 %; types 3a and 3dA were dominant in the Yellow Sea accounting for 49.51 % and 40.88 %, respectively. Temperature and salinity were identified as key environmental constraints influencing the distribution patterns of <em>Synechococcus</em>. At the sub-group level, clade IX and type 3dA showed distributions closely related to salinity, whereas types 3a were primarily influenced by dissolved oxygen. The findings underscored the significant correlations between the distribution patterns of <em>Synechococcus</em> and environmental properties, which were further supported by cluster results demonstrating similar patterns obtained through principal component analysis. These findings highlight the application potential of spatial niche analysis based on <em>Synechococcus</em> molecular markers in reflecting environmental changes in shelf seas. Future studies should focus on elucidating the molecular regulatory mechanisms governing the distribution patterns of <em>Synechococcus</em>, thereby providing a critical foundation for understanding the responses of keystone species to environmental stresses in shelf ecosystems.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"292 ","pages":"Article 105495"},"PeriodicalIF":2.1,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144240776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are shallow-water hydrothermal vents stable? A comparison of published maps of the Paleochori Bay (Milos, Greece) systems twenty years apart","authors":"Alice Oprandi ,&nbsp;Carlo Nike Bianchi ,&nbsp;Carla Morri ,&nbsp;Martina Canessa","doi":"10.1016/j.csr.2025.105494","DOIUrl":"10.1016/j.csr.2025.105494","url":null,"abstract":"<div><div>The shallow-water hydrothermal vents in Paleochori Bay (Milos Island, Greece) are among the most active and well-known volcanic systems in the world. Despite almost three decades of research, however, their spatial and temporal variability remains poorly understood because of the dearth of reliable and repeated measurements. Diachronic analysis on GIS (Geographical Information System) platform allowed comparing seafloor maps of the area produced in the 1990s and 2010s to assess spatial stability or change in the main hydrothermal features (largest microbial mats). Notwithstanding differences between methods and observers, the comparison provided suggestive evidence that in two decades the main hydrothermal features of Paleochori Bay have shifted from their original location and changed in both extent and composition. Our study is the first of this type on shallow-water hydrothermal vents; further studies in other regions and repeated mapping in Paleochori Bay will be needed to understand the dynamics of these systems, both for research and management.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105494"},"PeriodicalIF":2.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144184440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and temporal variability of hydrodynamics on the Amazon Continental Shelf: an observational approach","authors":"Pedro Paulo de Freitas ,&nbsp;Mauro Cirano ,&nbsp;Carlos Eduardo Peres Teixeira ,&nbsp;Sávio Jeliel Roque Melres ,&nbsp;Antony Kadu Carvalho dos Santos de Sousa ,&nbsp;Vando José Costa Gomes ,&nbsp;Camilo Andrés Guerrero-Martin ,&nbsp;Ariane Koch-Larrouy","doi":"10.1016/j.csr.2025.105491","DOIUrl":"10.1016/j.csr.2025.105491","url":null,"abstract":"<div><div>Amazon Continental Shelf (ACS) presents highly energetic hydrodynamics, modulated by multiple forcing mechanisms, and significant socio-economic and climate importance. This study characterizes the spatial-temporal variability of hydrodynamics on the ACS between 2°S and 4°N based on in situ data of 6 coastal sea level stations provided by IBGE, BNDO and SiMCosta, velocity measurements from 201 drifters of NOAA Global Drifter Program and 3 moorings of the AMANDES III project, and 127 CTD profiles from AMANDES and REVIZEE projects. The analysis of the coastal sea level shows that the tidal band contributes for 95 % (Santana, Amapá shelf) to 99 % (Turiaçu and Ribamar, Maranhão shelf) of the temporal variability of the sea level. Moreover, it shows that characteristics typical of a macrotidal regime occur up to 75 % and 41 % of the time at Turiaçu and Salinópolis, the eastern and central regions of the ACS, respectively. Velocity time series from drifters and moorings reveal a northwestward flow pattern along the ACS, which is associated with wind-driven circulation. The semidiurnal tides play a crucial role in the temporal variability of the cross-shelf velocity component, reaching a maximum percentage importance of 90 % on the central region of the ACS. Residual currents (without tides) are more pronounced in the alongshelf component. Their percentage importance increases towards the western shelf, from 68 % (73 %) and 20 % (10 %) in the upper (lower) water column at the eastern shelf, to 95 % (90 %) and 54 % (46 %) in the alongshelf and cross-shelf components, respectively. The wavelet analysis of the residual currents reveals high energy in two distinct period bands between 4 and 20 days and longer than 20 days at all moorings. The first period band is associated with wind modulations, while the second band indicates influence of the North Brazil Current (NBC) fluctuations. The time series of Richardson numbers show that the central and western shelves are stable for most of the time (&gt;70 %). The stratification (N2) and vertical velocity shear (S2) parameters increase toward MAM4 (western shelf) associated with the spreading of the Amazon River plume and the increased influence of the NBC on the speed and direction of currents in the outer shelf. The TS diagrams show the presence of three distinct water masses on the ACS: coastal water influenced by river discharge, mixed water, and oceanic water.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105491"},"PeriodicalIF":2.1,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatiotemporal features of storm surges in the Zhoushan Archipelago from 2001 to 2020","authors":"Zheng Guo ,&nbsp;Anzhou Cao ,&nbsp;Wenyao Ma ,&nbsp;Jicai Zhang ,&nbsp;Jinbao Song","doi":"10.1016/j.csr.2025.105492","DOIUrl":"10.1016/j.csr.2025.105492","url":null,"abstract":"<div><div>Storm surges pose a critical coastal hazard, necessitating accurate modelling and understanding of their behavior. In this study, the Coastal and Regional Ocean Community model has been used to investigate spatiotemporal features of storm surges in the Zhoushan Archipelago. Based on simulations over 20 typhoon seasons (2001–2020), we find that islands closer to the mainland generally exhibit higher surge levels than remote offshore islands, suggesting that islands are subjected to varying degree of risk during a storm surge event. However, the specific distribution of storm surges depends on typhoon trajectories. Offshore-deviating typhoons lead to a general eastward diminution of surges, while typhoons that make landfall south of Zhoushan result in maximum surge heights along the southwestern islands’ coasts. In terms of temporal variation, storm surge integrated intensity exhibits a slight increasing trend, likely influenced by the decreasing distance of typhoon maximum intensity from Zhoushan. Furthermore, the integrated intensity of storm surge correlates positively with El Niño and La Niña events, particularly in regions characterized by intense storm surges. These findings provide valuable reference for the development of risk prevention and mitigation strategies in Zhoushan and other island cities.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105492"},"PeriodicalIF":2.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Grazers play different roles in the microbial loop of oligotrophic and eutrophic subtropical marine ecosystems","authors":"Madeline Olivia ,&nbsp;Patrichka Wei-Yi Chen ,&nbsp;Wen-Chen Chou ,&nbsp;Vladimir Mukhanov ,&nbsp;Margarita Ufimtseva ,&nbsp;Tatiana Liashko ,&nbsp;Evgenii Sakhon ,&nbsp;Mariche Natividad ,&nbsp;An-Yi Tsai","doi":"10.1016/j.csr.2025.105490","DOIUrl":"10.1016/j.csr.2025.105490","url":null,"abstract":"<div><div>In planktonic oceanic communities, heterotrophic bacteria (HB), <em>Synechococcus</em> spp. (SYNE), <em>Prochlorococcus</em> (PRO), and phototrophic picoeukaryotes (PPE) (&lt;2 μm in size) are the numerically dominant groups. Recent advancements in understanding the physiology and ecology of these small cells have shed light on the significant roles that microbes play in global biogeochemical cycles and food webs. In order to investigate the interaction between HB, picophytoplankton and nanoflagellate grazers, estimated the effects of grazers on HB and picophytoplankton using the size-fractionation experiments at two stations in the subtropical western Pacific: Matsu (St. M) and Penghu (St. P). At St. M, there is clear evidence for top-down control of SYNE and PRO due to the relatively high abundance recorded in &lt;2 μm filtered treatment within the 24-h sampling period. In contrast, at St. P, where higher temperatures and lower nutrient levels were observed compared to St. M, we suggest that the bottom-up factor (resource supply) is the primary driver of picophytoplankton growth. Furthermore, while PPE may not be the most abundant group, it is a dominant contributor to picophytoplankton biomass at both stations. It highlights the complex ecology of microbial communities in different subtropical Pacific oceanic regions, providing new insights into the important role these organisms play in ocean carbon cycling.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105490"},"PeriodicalIF":2.1,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144139303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mesophotic banks of Dendrophyllia ramea offshore Marzamemi (Sicily, Ionian Sea): a habitat classification model","authors":"Valentina Alice Bracchi ,&nbsp;Luca Marino ,&nbsp;Verena Voulaz ,&nbsp;Alessandra Savini ,&nbsp;Luca Fallati ,&nbsp;Andrea Giulia Varzi ,&nbsp;Pietro Bazzicalupo ,&nbsp;Daniela Basso","doi":"10.1016/j.csr.2025.105489","DOIUrl":"10.1016/j.csr.2025.105489","url":null,"abstract":"<div><div>The occurrence and distribution of mesophotic autogenic habitat engineers are critical for the effective management and conservation of marine resources, as well as for regulating human activities. Recent deep-sea explorations in the Mediterranean Sea have revealed the occurrence of algal reefs (coralligenous), alongside notable contributions from invertebrates in creating reefs. As part of the CRESCIBLUREEF project, we investigated a sector offshore Marzamemi (Ionian Sea), at depths between 30 and 100 m, using integrated acoustic surveys and underwater videos. This study presents a detailed characterization of the acoustic facies associated with a dense population of <em>Dendrophyllia ramea</em>, a vulnerable arborescent scleractinian coral included in the cold-water coral group and recognized as habitat-former. Found between 65 and 90 m of depth in a muddy-sandy sedimentary environment, <em>D. ramea</em> forms small reef-like banks with patchily distributed colonies ranging in size from less than 10 cm to over 50 cm, generally on buried biogenic hard substrates, occupying an area of approximately 0.42 km². <em>D. ramea</em> functions as an autogenic habitat engineer, supporting rich epibenthic assemblages including abundant <em>Neopycnodonte cochlear</em> at the base of the colonies. However, evidence of marine litter, particularly abandoned ropes entangling the corals, indicates anthropogenic impacts, likely from fishing activities. By identifying the acoustic signature of <em>D. ramea</em> and validating it with in situ observations, this study successfully maps previously undocumented mesophotic coral banks in the Marzamemi area. Our findings underscore the ecological relevance and vulnerability of <em>D. ramea</em> habitats, highlighting the need for their inclusion in marine spatial planning and conservation strategies.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105489"},"PeriodicalIF":2.1,"publicationDate":"2025-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144106880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of inorganic water quality in marine areas affected by an artificial beach nourishment: A case study in northeastern Brazil","authors":"Luiz Carlos Nunes da Silva ,&nbsp;Ravena Santiago Alves ,&nbsp;Isabelle de Oliveira Lima ,&nbsp;Francisco Pereira Marques Neto ,&nbsp;Guilherme Ribeiro de Melo ,&nbsp;Francisca Cintia Silva do Nascimento ,&nbsp;Bárbara Pereira Paiva ,&nbsp;Kamila Vieira de Mendonça ,&nbsp;Rivelino Martins Cavalcante ,&nbsp;Maria Ozilea Bezerra Menezes ,&nbsp;Michael Barbosa Viana","doi":"10.1016/j.csr.2025.105488","DOIUrl":"10.1016/j.csr.2025.105488","url":null,"abstract":"<div><div>This study examines the impact of an artificial beach nourishment project on seawater quality at two beaches in Fortaleza, Ceará, Brazil. The research was conducted between October 2019 and May 2022. Twenty-seven inorganic water quality parameters were analyzed in five phases: at the beginning, during execution and in three phases after completion of the works. The distribution of chemicals in the marine sediment was also analyzed. The water analysis showed that the average concentrations of four parameters were above the maximum permissible values (MPV) established by the Brazilian standard in at least one phase of the study. The fluoride concentration reached 2.4 mg/L, exceeding the MPV of 1.4 mg/L. Polyphosphates recorded a maximum value of 0.085 mg/L, exceeding the MPV of 0.031 mg/L, while hydrogen sulfide reached 0.0023 mg/L, exceeding the MPV of 0.0020 mg/L. Total residual chlorine showed average concentrations above the MPV of 0.01 mg/L in all phases of the study, with a maximum value of 0.64 mg/L. On the basis of this study, there is no concrete evidence that the concentrations above the MPV are due to the artificial beach nourishment, as these concentration peaks were not only observed in the samples taken during the execution phase of the work. Furthermore, no significant permanent changes in the physical and chemical properties of the water were detected after the end of the work. The statistical differences observed in the inorganic water quality parameters can be attributed to the marine dynamics in the region, such as strong currents, mixing of water masses and the tidal regime. In addition, the study area is influenced by various anthropogenic activities that can contribute significantly to these changes. The analysis of metals and nutrients in the sediment revealed concentrations below the limits established by the Brazilian standard.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105488"},"PeriodicalIF":2.1,"publicationDate":"2025-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143934768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling intensity and frequency of seabed shear stress and sediment mobilization on the Canadian Pacific Shelf","authors":"M.Z. Li ,&nbsp;Y. Wu ,&nbsp;I. Fine ,&nbsp;P.F. Cummins","doi":"10.1016/j.csr.2025.105480","DOIUrl":"10.1016/j.csr.2025.105480","url":null,"abstract":"<div><div>Ocean surface waves and currents can interact to produce strong seabed shear stress and sediments mobilization affecting infrastructure safety and benthic habitat distribution. An accurate understanding of these processes is important to inform decisions taken to ensure sustainable development of the oceans. Modelled waves, tidal current and circulation current data for a 3-year period were used in a combined-flow sediment transport model to simulate the seabed shear stresses and the mobilization of observed sediments on the Pacific Shelf of Canada. The modelling results are presented and analyzed to update the framework of seabed disturbance and sediment mobility on the Pacific Shelf. The shelf is affected by strong waves and tidal currents. Maximum mean significant wave height over the modelled period can reach 3 m and mean near-bottom tidal currents reach up to 0.6 m s⁻¹. Our modelling results indicate that the mean wave and tidal current shear velocities reach the maximum values of 4 and 3 cm s⁻¹ respectively. Observed sediments on the Pacific Shelf can be mobilized by tidal currents at least once during the modelled 3-year period over 46 % of the shelf area while waves can mobilize sediments over 47 % of the shelf area suggesting nearly equal tidal and wave effects. Furthermore, waves and currents interact to cause enhanced combined wave-current shear velocities &gt;5 cm s⁻¹ that are capable of mobilizing sediments over 80 % of the shelf area, nearly double that due to tides or waves alone. Regionalization of disturbance types based on the spatial variation of the relative importance of component processes in mobilizing sediments, however, demonstrates that tide-dominant disturbance type accounts for 43 % of the shelf area while wave-dominant disturbance accounts for 32 % of the shelf area suggesting tidal disturbance is more important than waves on the Pacific Shelf. Mixed disturbance only occurs over a small 11 % of the shelf area. Universal indices of Seabed Disturbance (SDI) and Sediment Mobility (SMI) were applied to better quantify the exposure of the seabed to oceanographic processes and sediment mobility, incorporating both the magnitude and frequency of these processes. Strong casual correlation between modelled shear stress and observed grain sizes for a range of values and over widely distributed areas on the shelf suggests that sediments are largely in equilibrium with the present-day hydrodynamics on the Pacific Shelf of Canada. The spatial variation of modelled bed shear stress, its correlation with the observed grain size, and patterns of modelled sediment mobilization and disturbance types from our study support and potentially improve the surficial geology, morphology, and sedimentary process knowledge for several regions of the Pacific Shelf.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"291 ","pages":"Article 105480"},"PeriodicalIF":2.1,"publicationDate":"2025-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Escalating variability of daily sea temperature decreases phytoplankton spring blooms","authors":"Zixuan Sun ,&nbsp;Yan Du ,&nbsp;Dongdong Xiang","doi":"10.1016/j.csr.2025.105479","DOIUrl":"10.1016/j.csr.2025.105479","url":null,"abstract":"<div><div>Increases in sea surface temperature (SST) and its variability (SSTV) in the context of climate change have a great impact on marine phytoplankton productivity, but their combined effects on phytoplankton biomass, especially at a daily scale, have been poorly assessed. Here, we used an extended autoregressive (EAR) model to assess the different roles of SST and SSTV on phytoplankton spring blooms (PSB) in the Yellow Sea, based on 25 years (1998–2022) of daily-scale high-resolution chlorophyll-a (Chl-a) data from satellites. The annual patterns of PSB indices (start, peak, and duration) clearly exhibited years which were weak (low peak: Chl-a &lt;0.80 mg/m³; short duration: &lt;15 days) and strong (high peak: Chl-a &gt;1.0 mg/m³; long duration: &gt;60 days). The EAR model detected the significant effects of SST and SSTV on PSB indices, with SSTV being the more important determinant. SST is highly related to the timing of PSB start and end, with the average SST of 9.5 ± 0.7 °C at the start and 13.2 ± 1.95 °C at the end. The amplitude of SSTV was negatively correlated with the daily increase in Chl-a, highlighting the role of SSTV in modulating the magnitude of PSB. At low SST, the deepening of the mixed layer prolonged the time for phytoplankton to equilibrate nutrient and light requirements, whereas at low SSTV, the rate of environmental change within the mixed layer was reduced, allowing phytoplankton to adapt to the environment more quickly. Since the accumulation of phytoplankton biomass depends largely on daily acclimated growth, our results suggest that increasing daily temperature anomalies and warming in future are detrimental to phytoplankton biomass accumulation, and may reduce the magnitude of PSB in mid-to high-latitude seas.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105479"},"PeriodicalIF":2.1,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Vertical circulation and heat flux of coastal ocean fronts in the northwestern South China Sea","authors":"Keyi Tan ,&nbsp;Lingling Xie ,&nbsp;Junyi Li ,&nbsp;Mingming Li ,&nbsp;Qiang Li ,&nbsp;Quanan Zheng","doi":"10.1016/j.csr.2025.105478","DOIUrl":"10.1016/j.csr.2025.105478","url":null,"abstract":"<div><div>This study investigates the 3D structure and vertical circulation of the coastal ocean fronts in the northwestern South China Sea (NWSCS) by applying the generalized Omega equation to cruise observations in late August and early September 2018. The results reveal three summer density front zones (SUF1∼3) in the surface and subsurface layers. SUF1 is distributed along the coast with water depths shallower than 20 m and a density gradient larger than 0.2 × 10⁻³ kg m⁻⁴. It extends vertically from surface to bottom and is dominated by salinity gradient. In contrast, SUF2 and SUF3 are temperature-dominated frontal zones appearing in the offshore subsurface layer. SUF2 is in the cross-shelf direction between the 20-m and 40-m isobaths associated with upwelling waters originating from the south. The observed submesoscale fronts have a Rossby number of <em>O</em>(1). The diagnosed vertical velocities indicate that an upwelling peak of 4.2 × 10⁻⁵ m s⁻¹ is located near the coast in SUF1, while, in contrast, a maximum vertical velocity of −5.1 × 10⁻⁵ m s⁻¹ in the cross-shelf SUF2. Dynamic analysis results indicate that ageostrophic advection is the dominant term. The vertical heat fluxes derived from the vertical velocity and temperature anomaly are mainly positive both in SUF1 and SUF2, with a maximum value of 279.5 W m⁻² and 418.8 W m⁻², respectively, which are one order larger than the sea surface heat flux during the observation.</div></div>","PeriodicalId":50618,"journal":{"name":"Continental Shelf Research","volume":"290 ","pages":"Article 105478"},"PeriodicalIF":2.1,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143870034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}