Progress in Oceanography最新文献

{"title":"Perspectives on Northern Gulf of Alaska salinity field structure, freshwater pathways, and controlling mechanisms","authors":"Isaac Reister,&nbsp;Seth Danielson,&nbsp;Ana Aguilar-Islas","doi":"10.1016/j.pocean.2024.103373","DOIUrl":"10.1016/j.pocean.2024.103373","url":null,"abstract":"<div><div>The biologically productive Northern Gulf of Alaska (NGA) continental shelf receives large inputs of freshwater from surrounding glaciated and non-glaciated watersheds, and a better characterization of the regional salinity spatiotemporal variability is important for understanding its fate and ecological roles. We here assess synoptic to seasonal distributions of freshwater pathways of the Copper River discharge plume and the greater NGA continental shelf and slope using observations from ship-based and towed undulating conductivity-temperature-depth (CTD) instruments, satellite imagery, and satellite-tracked drifters. On the NGA continental shelf and slope we find low salinities not only nearshore but also 100–150 km from the coast (i.e. average 0–50 m salinities less than 31.9, 31.3, and 30.8 in spring, summer, and fall respectively) indicating recurring mid-shelf and shelf-break freshwater pathways. Close to the Copper River, the shelf bathymetry decouples the spreading river plume from the direct effects of seafloor-induced steering and mixing, allowing iron- and silicic acid-rich river outflow to propagate offshore within a surface-trapped plume. Self-organized mapping analysis applied to true color satellite imagery reveals common patterns of the turbid river plume. We show that the Copper River plume is sensitive to local wind forcing and exerts control over water column stratification up to ∼100 km from the river mouth. Upwelling-favorable wind stress modifies plume entrainment and density anomalies and plume width. Baroclinic transport of surface waters west of the river mouth closely follow the influence of alongshore wind stress, while baroclinic transport east of the river mouth is additionally modified by a recurring or persistent gyre. Our results provide context for considering the oceanic fate of terrestrial discharges in the Gulf of Alaska.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103373"},"PeriodicalIF":3.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142643110","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":"Changes in prey-predator interactions in an Arctic food web under climate change","authors":"Nicolas Dupont ,&nbsp;Joël M. Durant ,&nbsp;Øystein Langangen ,&nbsp;Leif Christian Stige","doi":"10.1016/j.pocean.2024.103380","DOIUrl":"10.1016/j.pocean.2024.103380","url":null,"abstract":"<div><div>Global warming affects marine ecosystems by changing environmental conditions, ecosystem structure, and ecosystem functioning. In parts of the Arctic, increased sea temperature and decreased sea ice have led to a poleward expansion of boreal species and increased their interactions with native Arctic species. To investigate and quantify the changing interactions in an Arctic marine food web under new environmental conditions, we studied the interactions between key prey fish species in the seasonally ice-covered parts of the Barents Sea: adult polar cod (<em>Boreogadus saida</em>) and capelin (<em>Mallotus villosus</em>) and one of the major predators in the system: Atlantic cod (<em>Gadus morhua</em>). For this, we compared the predictive performance of threshold models predicting the abundance of adult polar cod as a function of Atlantic cod. Each model was associated with a hypothesis describing prey-predator interactions in different environmental conditions defined by threshold values of summer sea-ice or capelin stock biomass. The best predictive model showed that the predation effect of Atlantic cod on polar cod was strongest in years of low summer sea ice cover and low capelin stock biomass. Our results exemplified that Arctic species such as polar cod may experience increased predation pressure under climate change from boreal species such as Atlantic cod. These effects depend, however, not only on changes in abiotic drivers of species distributions, but also on food-web interactions involving mid-trophic level species such as capelin.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103380"},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Seasonal variations of the cold intermediate layer on the Newfoundland and Labrador Shelf","authors":"H.J. Andres,&nbsp;N. Soontiens,&nbsp;J. Penney,&nbsp;F. Cyr","doi":"10.1016/j.pocean.2024.103379","DOIUrl":"10.1016/j.pocean.2024.103379","url":null,"abstract":"<div><div>Across the Newfoundland and Labrador (NL) continental shelf, sub-surface temperatures remain below 0°C throughout the summer, when the surface is much warmer. This oceanographic feature is known as a cold intermediate layer (CIL), and its properties are assessed annually in the region to support ocean climate research and fisheries management. Monitoring in this region is either too infrequent or too sparse spatially to provide a detailed picture of sub-annual variations, so the GLORYS12 global ocean reanalysis is used for this purpose. GLORYS12 is shown to reproduce both the signs and magnitudes of inter-annual variations in CIL area on NL Shelf transects, although the magnitude of the seasonal cycle may be under-estimated.</div><div>GLORYS12 indicates that sub-zero water volume is maximized across the region during March and decreases with time, beginning in the south and proceeding north. CIL minima are reached between November to December at most shelf locations, proceeding in the opposite direction. Stratification triggered by surface freshwater is an important contributor to CIL seasonal changes on all transects on the NL Shelf. While the CIL area tends to gradually erode throughout the summer, the downstream advection of CIL water from more northern transects leads to the development of secondary CIL area maxima during late August to early September on the Newfoundland component of the shelf. Onshore intrusions either at the shelf break or via cross-shelf troughs contribute to the erosion of CIL area from below at some transects, although this effect may be exaggerated in the model.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103379"},"PeriodicalIF":3.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655865","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":"Reduced phytoplankton biomass in a subtropical plume-upwelling system induced by typhoons Bailu and Podul","authors":"Zhuyin Tong ,&nbsp;Lingqi Ma ,&nbsp;Shujie Cai ,&nbsp;Zhaoyun Chen ,&nbsp;Lei Wang ,&nbsp;Mingwang Xiang ,&nbsp;Rui Huang ,&nbsp;Meilin Wu ,&nbsp;Wupeng Xiao ,&nbsp;Bangqin Huang","doi":"10.1016/j.pocean.2024.103375","DOIUrl":"10.1016/j.pocean.2024.103375","url":null,"abstract":"<div><div>Phytoplankton responses to typhoons are pivotal for understanding the impact of climate change on marine biodiversity and productivity, yet current literature, focusing on typhoon-induced biomass increases from nutrient dynamics, might overlook the complexity of plume-upwelling interactions during such events. This study, therefore, examines the sequential impact of Typhoons Bailu and Podul on phytoplankton biomass and community structure in the northern South China Sea, a region where the interplay of riverine discharges and oceanic upwelling shapes the ecological landscape. Employing a combination of in-situ hydrographic measurements, pigment analysis, and satellite data, we tracked the pre- and post-typhoon phytoplankton dynamics, capturing a detailed picture of their response to the rapid hydrodynamic changes induced by these meteorological disturbances. Prior to Typhoon Bailu, a synergetic interaction between the Pearl River plume and coastal upwelling resulted in a diatom-rich phytoplankton assemblage. The passage of Typhoon Bailu followed by Typhoon Podul uncoupled this synergy, leading to phosphate scarcity and a notable decline in overall phytoplankton biomass. This decoupling favored the proliferation of smaller phytoplankton such as <em>Synechococcus</em> and haptophytes_T8, indicating a shift towards a community adapted to phosphate-poor environments. The distinct phytoplankton response patterns observed in this study not only challenge existing paradigms about typhoon impacts on marine productivity but also highlight the complex and potentially transformative effects of typhoon-induced hydrodynamic alterations, although whether the pattern of biomass reduction is generalizable to all similar typhoon events remains uncertain. These insights are essential for modeling the ecological ramifications of such disturbances, which is becoming increasingly important as the frequency and intensity of extreme weather events continue to rise.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103375"},"PeriodicalIF":3.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655937","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":"C:N stoichiometry and the fate of organic carbon in ecosystems of the northwest Pacific Ocean","authors":"Chuanli Zhang ,&nbsp;Yaoyao Wang ,&nbsp;Rong Bi ,&nbsp;Ulrich Sommer ,&nbsp;Guodong Song ,&nbsp;Zhaohui Chen ,&nbsp;Feng Lin ,&nbsp;Jing Zhang ,&nbsp;Meixun Zhao","doi":"10.1016/j.pocean.2024.103372","DOIUrl":"10.1016/j.pocean.2024.103372","url":null,"abstract":"<div><div>Phytoplankton elemental composition regulates the efficiency of energy and material transfer in the interface between phytoplankton and their consumers. The ratio of particulate organic carbon to particulate organic nitrogen (POC:PON) shows considerable regional deviations from the canonical Redfield ratio in the global surface ocean. However, in certain oceanic regions such as the northwest Pacific Ocean (NWPO) POC:PON distribution and its ecological significance remain uncertain. We investigated surface ocean POC:PON distributions at 66 stations in the NWPO, and quantified the correlations between POC:PON and multiple biotic and abiotic factors including sea surface temperature (SST), nutrient concentrations and multiple lipid biomarkers (fatty acids and sterols), by combining correlation analyses and generalized additive models. POC:PON (range: 3.53–14.18 M ratios; median: 6.89) was overall higher in the (sub)tropical biome than that in the high-latitude biome. In the entire study region, SST, nutrient concentration and lipid-derived phytoplankton community structure explained 41 %, 33 % and 26 % of the variance in POC:PON, respectively, while the respective importance of each factor differed between the (sub)tropical and high-latitude biomes. Furthermore, we calculated the percentage of primary production consumed by herbivores (PPC; 54–156 %), showing a higher mean value (117 %) in the high-latitude biome and a lower one (92 %) in the (sub)tropical biome. The spatial distribution pattern of PPC can be attributed to multiple factors, with PPC correlating negatively with SST and positively with lipid-based indicators of phytoplankton food quality and POC concentrations. The increase in SST may be associated with a reduced nitrogen content, resulting in lower PPC in the (sub)tropical biome. This study highlights the significance of SST and elemental and biochemical composition of phytoplankton in regulating the transfer of organic carbon to herbivores in the NWPO.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103372"},"PeriodicalIF":3.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655936","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":"Global characterization of modelled micronekton in biophysically defined provinces","authors":"S. Albernhe ,&nbsp;T. Gorgues ,&nbsp;P. Lehodey ,&nbsp;C. Menkes ,&nbsp;O. Titaud ,&nbsp;S. Magon De La Giclais ,&nbsp;A. Conchon","doi":"10.1016/j.pocean.2024.103370","DOIUrl":"10.1016/j.pocean.2024.103370","url":null,"abstract":"<div><div>Micronekton are the mid-trophic level of the ecosystem and contribute to active carbon export to the deep ocean through diel vertical migrations. Better characterization of micronekton functional groups depending on relationships to environmental variables is useful for the management of marine resources, the conservation of biodiversity and a better understanding of climate change impacts. For this purpose, regionalization of global ocean into homogeneous provinces is an approach that is generating increasing interest. However, published regionalizations efforts (i) derived from environmental forcings, that do not specifically focus on micronekton and (ii) derived from acoustic backscatter, which do not allow direct estimates of micronekton biomass. Here, we propose to fill the gap between biophysical regionalizations and micronekton biomass. We notably defined biophysical biomes using global environmental variables known to affect micronekton: temperature of the epipelagic layer, temperature stratification, and net primary production (NPP). Six biophysical biomes were defined with a clustering method. A characterization of these biophysical biomes with simulated micronekton from the SEAPODYM-LMTL model displayed biome-specific relationships between biomass and the environmental variables used in the clustering (i.e. biomasses mostly structured by NPP and temperature). Biophysical biomes also displayed specific vertical structures suggested by modelled micronekton functional groups ratios. Then, a validation of biophysical biomes’ boundaries was performed to identify potential vertical structure reorganization in acoustic backscattering response from adjacent biomes. The regionalization identified homogeneous areas in terms of acoustic vertical structure, which were also different between adjacent biomes. Finally, a comparison with another biomes’ definition computed from micronekton biomasses suggested that environmental variables can account for only some of the variability of the micronekton structures.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103370"},"PeriodicalIF":3.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Pre-molt dispersal and use of marine protected areas by Southern Rockhopper Penguins (Eudyptes chrysocome) at the southernmost oceanic regions of South America","authors":"Samanta Dodino ,&nbsp;Ulises Balza ,&nbsp;Luciana Riccialdelli ,&nbsp;Michael J. Polito ,&nbsp;Klemens Pütz ,&nbsp;Andrea Raya Rey","doi":"10.1016/j.pocean.2024.103369","DOIUrl":"10.1016/j.pocean.2024.103369","url":null,"abstract":"<div><div>Marine Protected Areas (MPAs) are crucial for conserving marine biodiversity, and assessing the effectiveness of boundaries in protecting marine species is essential. In the Southwest Atlantic Ocean, four MPAs have been created. In this study we evaluate the use of these MPAs by Southern Rockhopper Penguins (<em>Eudyptes chrysocome</em>) that nest at Isla de los Estados, Argentina during the pre-molt period in February and March 2020 by combining geolocation sensor data and spatial analysis together with stable isotopes analysis (<em>δ</em>¹³C and <em>δ</em>¹⁵N) to assess their spatial and trophic niches. We recaptured 16 of 25 adults to which loggers had been attached (64 % recapture rate, 6 females and 10 males). Penguins dispersed mainly southward and used the MPAs as corridors towards feeding area such as the Antarctic Polar Frontal Zone (APFZ). We found no evidence of sex-specific spatial and trophic niche partitioning. To develop robust conservation strategies, future studies should span multiple years and enhanced sampling effort to comprehensively explore the pre-molt trophic ecology and at-sea distribution of Southern Rockhopper Penguins.</div></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"229 ","pages":"Article 103369"},"PeriodicalIF":3.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655933","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":"Variation of amino acid in the sinking particulates in the northeastern Arabian Sea and the northern Bay of Bengal","authors":"Apsara P Vijayan,&nbsp;Siby Kurian,&nbsp;Duphrin Joseph,&nbsp;Megha Dixon,&nbsp;Harshada Kankonkar,&nbsp;Rakhee Khandeparker,&nbsp;Supriya Karapurkar,&nbsp;Anand Methar","doi":"10.1016/j.pocean.2023.103168","DOIUrl":"10.1016/j.pocean.2023.103168","url":null,"abstract":"<div><p>Sediment traps are widely used to get insight into how particulate matter forms and settles in the water column. Earlier studies in the Northern Indian Ocean have shown that the sinking flux depends mainly on surface primary production and varies seasonally and inter-annually. In the case of the Bay of Bengal, river runoff plays a significant role in the sinking flux. As a part of the SIBER-INDIA program, a mooring consisting of sediment traps was deployed at three depths (495 m, 1205 m, and 2915 m) in the Arabian Sea (Northeastern Arabian Sea sediment trap, NEAST;<!--> <!-->16.87°N, 67.77°E) and at 580 m, 1110 m, and 1635 m in the Bay of Bengal (Bay of Bengal sediment trap, BoBST; 18.21°N, 89.63°E). We present here data on total fluxes, concentrations of particulate carbon and nitrogen, biogenic opal, and amino acid composition for the period 2017–2018 in both basins. Particle flux in the Arabian Sea was influenced by monsoon-related processes with higher flux during the northeast monsoon (NEM) and southwest monsoon (SWM) seasons, whereas the flux was higher in BoB during SWM. Particulate nitrogen (PN), particulate organic carbon (POC), and total hydrolysable amino acid (THAA) mostly decreased with depth in all traps due to the decomposition of labile organic constituents in the sinking flux. Changes in the decomposition of organic matter with depth were further reflected in the POC/PN molar ratios, which increased with depth in the Arabian Sea. A low POC/PN molar ratio associated with the higher THAA concentration in most of the shallow traps indicates the presence of fresher organic matter. Among the THAA, Glycine (Gly) was the dominant amino acid in all the samples followed by Aspartic acid (Asp), Glutamic acid (Glu), Serine (Ser), and Alanine (Ala). The amino acid-based degradation index (DI) reveals the degradation of labile organic matter with depth in the NEAST. However, the middle trap in the BoB showed a different trend with higher total and lithogenic fluxes, POC, PN, and DI values compared to the shallow trap indicating lateral advection in the bay. Monsoonal changes and mesoscale eddies make these basins distinct from one another and influence their sinking fluxes and biogeochemical settings.</p></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"219 ","pages":"Article 103168"},"PeriodicalIF":4.1,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71491710","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":"Hydrography, inorganic nutrients and chlorophyll a linked to sea ice cover in the Atlantic Water inflow region north of Svalbard","authors":"Angelika H.H. Renner ,&nbsp;Allison Bailey ,&nbsp;Marit Reigstad ,&nbsp;Arild Sundfjord ,&nbsp;Melissa Chierici ,&nbsp;Elizabeth M. Jones","doi":"10.1016/j.pocean.2023.103162","DOIUrl":"10.1016/j.pocean.2023.103162","url":null,"abstract":"<div><p>Changes in the inflow of Atlantic Water (AW) and its properties to the Arctic Ocean bring more warm water, contribute to sea ice decline, promote borealisation of marine ecosystems, and affect biological and particularly primary productivity in the Eurasian Arctic Ocean. One of the two branches of AW inflow follows the shelf break north of Svalbard, where it dominates oceanographic conditions, bringing in heat, salt, nutrients and organisms. However, the interplay with sea ice and Polar Surface Water (PSW) determines the supply of nutrients to the euphotic layer especially northeast of Svalbard where AW subducts below PSW. In an effort to build up a time series monitoring the key characteristics of the AW inflow, repeat sampling of hydrography, macronutrients (nitrate, phosphate and silicate), and chlorophyll <em>a</em> (chl <em>a</em>) was undertaken along a transect across the AW inflow at 31<span><math><mrow><mo>°</mo><mi>E</mi></mrow></math></span>, 81.5<span><math><mrow><mo>°</mo><mi>N</mi></mrow></math></span> since 2012 — first during late summer and in later years during early winter. Such time series are scarce but invaluable for investigating the range of variability in hydrography and nutrient concentrations. We investigate linkages between late summer hydrographic conditions and nutrient concentrations along the transect and the preceding seasonal dynamics of surface chl <em>a</em> and sea ice cover in the region north of Svalbard. We find large interannual variability in hydrography, nutrients and chl <em>a</em>, indicating varying levels of nutrient drawdown by primary producers over summer. Sea ice conditions varied considerably between the years, impacting upper ocean stratification, light availability and potential wind-driven mixing, with a strong potential for steering chl <em>a</em> concentration over the productive season. Early winter measurements show variable efficiency of nutrient re-supply through vertical mixing when stratification was low, related to autumn wind forcing and sea ice conditions. While this re-supply elevates nutrient levels sufficiently for primary production, it likely happens too late in the season when light levels are already low, limiting the potential for autumn blooms. Such multidisciplinary observations provide insight into the interplay between physical, chemical and biological drivers in the marine environment and are key to understanding ongoing and future changes, especially at this entrance to the central Arctic Ocean.</p></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"219 ","pages":"Article 103162"},"PeriodicalIF":4.1,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0079661123002057/pdfft?md5=02ca12e483e0bc3173eba7a401dade5a&pid=1-s2.0-S0079661123002057-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71512736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A local eddy viscosity parameterization for wind-driven estuarine exchange flow, Part II: Entrainment","authors":"N. Berkay Basdurak ,&nbsp;Hans Burchard ,&nbsp;Henk M. Schuttelaars","doi":"10.1016/j.pocean.2023.103166","DOIUrl":"10.1016/j.pocean.2023.103166","url":null,"abstract":"<div><p><span>Structure and intensity of estuarine exchange flow depend significantly on the eddy viscosity </span><span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>v</mi></mrow></msub></math></span> profile which is dynamically linked to various forces (e.g., gravitational, tidal, wind-driven). The impact of winds on the exchange flow is complex due to its direct (local and remote changes in shear and density stratification) and indirect (modifications to <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>v</mi></mrow></msub></math></span> profiles) contributions. This study aims (i) to include wind entrainment effects in the tidally averaged <span><math><msub><mrow><mi>A</mi></mrow><mrow><mi>v</mi></mrow></msub></math></span><span> parameterization; (ii) to develop an analytical one-dimensional model for the wind driven exchange flow by using this novel parameterization and assess the tidally averaged dynamics over a relevant physical parameter-space, subdomains of which have not yet been explored numerically. This one-dimensional model is based on a balance between frictional forces and pressure gradient, calibrated with a tidally-resolving one-dimensional water-column model with second-moment closure. Structure and intensity of the resulting exchange flow profiles are analyzed with respect to three dimensionless parameters (the unsteadiness of boundary layer mixing </span><span><math><msub><mrow><mi>U</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span>, scaled-directional wind stress <span><math><mi>W</mi></math></span>, and horizontal stratification <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>). While down-estuarine winds enhance the gravitational circulation, up-estuarine winds result in either a two-layer inverted circulation opposing the gravitational circulation, or a three-layer flow (favored by relatively strong <span><math><msub><mrow><mi>S</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, weak <span><math><mi>W</mi></math></span>, and moderate <span><math><msub><mrow><mi>U</mi></mrow><mrow><mi>n</mi></mrow></msub></math></span><span>) that is up-estuarine at the surface with classical two-layer circulation underneath. Relative thickness of surface and bottom boundary layers affect both the intensity and the inflection depth of the exchange flow layers. Up-estuarine winds with </span><span><math><mrow><mi>W</mi><mo>≳</mo><mn>0</mn><mo>.</mo><mn>5</mn></mrow></math></span> yield unstable stratification and reduce the exchange flow intensity with increasing <span><math><mi>W</mi></math></span>.</p></div>","PeriodicalId":20620,"journal":{"name":"Progress in Oceanography","volume":"219 ","pages":"Article 103166"},"PeriodicalIF":4.1,"publicationDate":"2023-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71491595","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}