Deep-sea Research Part Ii-topical Studies in Oceanography最新文献

{"title":"Larval fish community in the Bay of Whales (eastern Ross sea): Species composition, relative abundance and spatial distribution","authors":"Mario La Mesa ,&nbsp;Federico Calì ,&nbsp;Antonio Di Franco ,&nbsp;Emilio Riginella ,&nbsp;Fortunata Donato ,&nbsp;Stefania Russo ,&nbsp;Chiara Papetti ,&nbsp;Pasquale Castagno ,&nbsp;Francesco Memmola ,&nbsp;Enrico Zambianchi","doi":"10.1016/j.dsr2.2024.105369","DOIUrl":"https://doi.org/10.1016/j.dsr2.2024.105369","url":null,"abstract":"<div><p>Early life stages of fish represent a key component in the food chain of the pelagic ecosystem of the Southern Ocean, connecting producer trophic levels to those of higher predators. Pelagic larvae and early juveniles of notothenioid fishes overwhelmingly dominate the ichthyoplankton community living on the continental shelf. Scientific research surveys targeting early life stages of fish in the pelagic realm have been mainly carried out in the western Ross Sea, whereas the eastern side can be considered unexplored. As source of high primary production, the presence and timing of formation of wide ice-free areas throughout the year in the Ross Sea play a fundamental role in structuring larval fish community. The Ross Ice Shelf Polynya (RISP) is a large coastal polynya, which is driven and maintained by local prevailing winds and oceanic currents. In the present study, we report the first data on species composition, relative abundance and spatial distribution of larval fish community found off the Bay of Whales in the eastern Ross Sea. As reported for other areas of the Ross Sea, the Antarctic silverfish <em>Pleuragramma antarcticum</em> was by far the most abundant species, followed by other nototheniids and channichthyids in smaller amounts. The huge abundance of <em>P. antarcticum</em> early larvae supports the hypothesis of a potential nursery area near the Bay of Whales. Present results strongly advocate for future investigations in these poorly known and remote areas.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"214 ","pages":"Article 105369"},"PeriodicalIF":3.0,"publicationDate":"2024-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064524000134/pdfft?md5=2a28f5d47d120b748c8357f27b5ae80d&pid=1-s2.0-S0967064524000134-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140052132","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":"Temporal shifts in prokaryotic metabolism in response to organic carbon dynamics in the mesopelagic ocean during an export event in the Southern ocean","authors":"Rachel R.-P. Rayne ,&nbsp;Sarah L.C. Giering ,&nbsp;Manuela Hartmann ,&nbsp;Joost Brandsma ,&nbsp;Richard D. Sanders ,&nbsp;Claire Evans","doi":"10.1016/j.dsr2.2024.105368","DOIUrl":"https://doi.org/10.1016/j.dsr2.2024.105368","url":null,"abstract":"<div><p>As the major term in downward organic carbon flux attenuation, determining prokaryotic metabolism over depth in the mesopelagic ocean is crucial for constraining the efficiency of the gravitational biological carbon pump (BCP). We hypothesize that the enhancement of particulate organic carbon (POC) concentrations in the mesopelagic twilight zone during export events leads to a temporally dynamic prokaryotic metabolic response, which likely has consequences for the efficiency of the BCP. We tested this hypothesis by making repeated measurements of leucine assimilation and leucine respiration at in situ concentrations over six depths throughout the upper 500 m of the water column during the collapse of a large-scale Southern Ocean spring diatom bloom. Rates of prokaryotic leucine assimilation were used to indicate levels of prokaryotic heterotrophic production, and leucine assimilation efficiency (LAE; the proportion of leucine used for growth versus respiration) was taken as an indicator of prokaryotic growth efficiency. Thus, relative shifts in LAE are indicative of shifts in rates of prokaryotic production relative to respiration. The flux of POC through the oceans’ interior led to a dynamic prokaryotic response, characterized by a temporary elevation in mesopelagic prokaryote leucine assimilation rates, LAE and prokaryotic abundance. By the final measurement these changes had already begun to revert, despite POC concentrations still being enriched. As hypothesized, our data revealed distinctions in the phases of the mesopelagic system, likely due to an evolution in bulk prokaryotic metabolic status and the amount and composition of organic matter available. This indicates that estimating ocean carbon sequestration during export events necessitates a time course of measurements throughout the period of POC downward flux. Our findings also revealed distinctions in the ecophysiological prokaryotic responses to substrate regimes between the surface mixed layer and the mesopelagic. Specifically, in the latter in situ leucine concentrations appeared more significant in controlling prokaryote metabolism than POC concentration, and were more closely related to per cell leucine assimilation, than respiration. Whereas, in the mixed layer, the concentration of in situ leucine did not seem to drive rates of its assimilation, rather POC concentration was a strong negative driver of cell specific leucine respiration. These findings are suggestive of stronger levels of energy limitation in the deeper ocean. We surmised that ocean regions with sporadic substrate supply to the mesopelagic are likely to experience stronger energy limitation which favors prokaryotic respiration over production.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"214 ","pages":"Article 105368"},"PeriodicalIF":3.0,"publicationDate":"2024-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064524000122/pdfft?md5=6349d79dd5fcf14c715450d180363c1a&pid=1-s2.0-S0967064524000122-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139749635","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":"The spatial distribution and environmental effects on hotspots and coldspots of micronekton in the southwestern Indian Ocean","authors":"Shujie Wan ,&nbsp;Xinjun Chen","doi":"10.1016/j.dsr2.2024.105367","DOIUrl":"10.1016/j.dsr2.2024.105367","url":null,"abstract":"<div><p><span><span>Micronekton<span><span> communities show large-scale spatiotemporal patterns in pelagic acoustic scattering layers. They are one of the most conspicuous and ecologically-important components of the vast </span>mesopelagic zone of the world's oceans. They play an important role in </span></span>fishery resources and </span>marine ecology<span> research. In this study, acoustic data from the southwestern Indian Ocean were used to perform a hotspot analysis exploring the differences in micronekton distribution at 16 different spatial scales. Moreover, a generalized additive model (GAM) was used to analyze the effects of environmental variables. The distribution of micronekton was found to be highly correlated with latitude at different spatial scales, with high-density areas (hotspots) distributed between 32°S and 42°S and low-density areas (coldspots) distributed between 43°S and 54°S. With increasing spatial scale, the centers of both high- and low-density micronekton areas tended to move southward. GAM analysis at 20′ × 20′ spatial scale revealed that the micronekton distribution was influenced by the interaction of multiple environmental variables, with photosynthetically active radiation and dissolved oxygen being the two key variables with the highest influence on hotspot and coldspot distributions. The present study provides indepth knowledge on which environmental variables influences the distribution of micronekton under hotspots and coldspots periods in the southwestern Indian Ocean.</span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"214 ","pages":"Article 105367"},"PeriodicalIF":3.0,"publicationDate":"2024-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139509413","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":"Changing marine biosphere in the West Pacific Ocean","authors":"Hong G,&nbsp;Zuo F,&nbsp;Qin K","doi":"10.1016/j.dsr2.2024.105357","DOIUrl":"10.1016/j.dsr2.2024.105357","url":null,"abstract":"","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"214 ","pages":"Article 105357"},"PeriodicalIF":3.0,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139104063","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":"Acoustic characterization of fish and macroplankton communities in the seychelles-chagos thermocline ridge of the southwest Indian ocean","authors":"Myounghee Kang ,&nbsp;Sunyoung Oh ,&nbsp;Wooseok Oh ,&nbsp;Dong-Jin Kang ,&nbsp;SungHyun Nam ,&nbsp;Kyounghoon Lee","doi":"10.1016/j.dsr2.2023.105356","DOIUrl":"10.1016/j.dsr2.2023.105356","url":null,"abstract":"<div><p>In this study, we describe the dynamics of the sound scattering layers (SSLs), particularly those of fish and macroplankton communities in the epipelagic layer, in the Seychelles-Chagos Thermocline Ridge (SCTR) of the southwest Indian Ocean using hydroacoustic data, net sampling, and oceanographic information. Overall, the acoustic backscattering values of the fish community were considerably higher than those of the macroplankton. Both communities were more densely distributed in the SCTR than in its surrounding region. On the vertical profile, the acoustic peak of the fish community was at 17 m during the day; however, considerably high values of up to 82 m were observed at night. Below 26 m, macroplankton was seldom found, regardless of the time. Hydrographic properties, such as temperature, salinity, dissolved oxygen (DO), and chlorophyll fluorescence, in the SCTR, were similar; however, an area at 5–8°S, 67°E was cooler, saltier, and had slightly lower DO. Weak or moderate positive correlations were observed between acoustic and hydrographic features. Based on all net samples, the most abundant taxon in terms of the total number of samples was found to be krill (<em>Euphausiacea</em>, 81%), followed by lantern fish (<em>Myctophum punctatum</em>, 12%). Understanding the dynamics of SSLs, particularly epipelagic organisms, will help to better clarify the important ecological roles of these organisms and their ability to facilitate vertical incorporation into marine food webs.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"213 ","pages":"Article 105356"},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064523001066/pdfft?md5=d961a1d4648ad011bd5cba3a7384fe79&pid=1-s2.0-S0967064523001066-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139077639","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":"The role of subsurface instabilities for increasing chlorophyll concentrations in a warming southern Indian ocean","authors":"Yi Xu ,&nbsp;Ying Wu ,&nbsp;Jing Zhang","doi":"10.1016/j.dsr2.2023.105355","DOIUrl":"10.1016/j.dsr2.2023.105355","url":null,"abstract":"<div><p>A warming climate is expected to intensify the stratification of the upper ocean in tropical and subtropical regions, which in turn results in decreases in the primary productivity for these oligotrophic areas. To assess if there is trended change in primary productivity in the southern Indian Ocean (IO) with known striking temperature increase, we use 17-years of satellite chlorophyll (Chl) data and model output to examine the trended changes in Chl. The results exhibited a surprisingly increase in Chl concentrations in part of the southern IO over the gyre area. To investigate the potential mechanisms underlying this Chl increase, we used temperature/salinity observations to re-evaluate stratification in the southern IO. The southern IO experienced basin-wide surface warming over the time series however there was a region of subsurface cooling at 50–100 m around 10°S. In the subtropical IO gyre, subsurface warming occurs at faster rates compare to the surface. Through the calculation of buoyancy frequency (<span><math><mrow><msup><mi>N</mi><mn>2</mn></msup></mrow></math></span>), we have confirmed the presence of subsurface instabilities caused by these inhomogeneous trends in the vertical thermohaline structure. This was particularly true over the southern IO gyre, which experienced sustained increase of surface mixing disturbances over the last decade—resulting in a more favorable environment for vertical transport of nutrients into the euphotic zone. A mixed layer nutrient budget analysis suggested that entrainment due to mixed layer deepening is crucial in delivering nutrients into the gyre's upper mixed layer, which fueled phytoplankton activity. This emphasizes the importance of considering subsurface instabilities when interpreting the factors that influence surface Chl variabilities. This study highlights the importance of a three-dimensional framework for examining stratification to assess future marine ecosystem responses to a changing climate.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"213 ","pages":"Article 105355"},"PeriodicalIF":3.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064523001054/pdfft?md5=5eab838ebc302fe0315c058764387acc&pid=1-s2.0-S0967064523001054-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139077738","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":"Investigation of ocean environmental variables and their variations associated with major Loop Current eddy-shedding events in the Gulf of Mexico","authors":"Nazanin Chaichitehrani,&nbsp;Ruoying He","doi":"10.1016/j.dsr2.2023.105354","DOIUrl":"10.1016/j.dsr2.2023.105354","url":null,"abstract":"<div><p>The eddy kinetic energy (EKE) variability associated with 26 major Loop Current eddies (LCEs) in the Gulf of Mexico from 1994 through 2019 was investigated. We employed 3D multivariate observation-based ARMOR3D monthly ocean analyses of salinity, temperature, and geostrophic velocity field data. In addition, we used ERA5 wind data, the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric global climate reanalysis, to analyze internal and external forcing processes affecting the evolution of these LCEs. The energy analysis was performed to understand the role of barotropic (BT) and baroclinic (BC) instabilities and their associated energy conversion mechanisms in EKE generation. Our results suggest that BT instabilities are the primary source of EKE variability in the upper water column of the LC system. Furthermore, BT was positively correlated with Yucatan Channel (YC) transport during these major LCE shedding events. YC transport plays a significant role in energy conversion from mean kinetic energy to EKE, Loop Current growth, and generation of LCEs. BC instability was inversely correlated with buoyancy frequency, and a decrease in stratification triggers the development of BC instability, which favors eddy shedding. An eddy shedding index (ESI) was developed to quantify EKE evolution. Major LCE shedding occurs when ESI ≥0.46.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"213 ","pages":"Article 105354"},"PeriodicalIF":3.0,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064523001042/pdfft?md5=b1dce769738c3586c08cdbe69506b447&pid=1-s2.0-S0967064523001042-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138690385","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 sinking velocities in Austral diatom blooms: Lessons learned from COMICS","authors":"M. Villa-Alfageme ,&nbsp;N. Briggs ,&nbsp;E. Ceballos-Romero ,&nbsp;F. de Soto ,&nbsp;C. Manno ,&nbsp;S.L.C. Giering","doi":"10.1016/j.dsr2.2023.105353","DOIUrl":"10.1016/j.dsr2.2023.105353","url":null,"abstract":"<div><p>The sinking velocity (SV) of organic particles is a critical driver of carbon transport to the deep sea. Accurate determination of marine particle SV and their influencing factors is therefore a key to better understanding of biological carbon storage in the ocean. We used two different approaches to estimate average SVs of particles during a Southern Ocean spring bloom (North of South Georgia): optical backscatter sensors on gliders (“large”, &gt;50 μm diameter), and radioactive pairs (²³⁴Th–²³⁸U and ²¹⁰Po-²¹⁰Pb). Our results were complemented with time-of flight estimations of bulk SVs from deep sediment traps deployed at 1950 m.</p><p>Bulk SVs increased consistently with depth from 15 ± 1 m d⁻¹ at 10 m to 50 ± 10 m d⁻¹ at the depth of export (Z_p = 95 m) and from 96 ± 35 m d⁻¹ at 150 m to 119 ± m d⁻¹ at 450 m. Only the fastest particles, mainly comprised by faecal pellets (FPs) and diatom aggregates, survived remineralization and dominated carbon fluxes at deep depth.</p><p>The SV variability at the base of the Euphotic Zone was studied in relation to the stage of the bloom by analysing three different moments of the spring diatom bloom in the region during the years 2012, 2013 and 2017. The export efficiency (<em>ExpEff)</em>, defined as the ratio POC flux exported below the Euphotic Zone to the satellite derived surface NPP, was also evaluated. It was found from the temporal series that <em>ExpEff</em> and SV vary throughout the diatom bloom as the community structure progresses. A good correlation between both variables was observed (<em>ExpEff</em> = <em>(0.023 ± 0.006) SV</em>, r = 0.82, p = 0.04). Showing that the variability in how efficiently the carbon flux is exported out of the Euphotic Zone can be explained by the SV at which the particles sink. Further investigations are required to analyse if this is a specific model of the functioning of the BCP during the diatom bloom in North South Georgia or if it can be extrapolated to other scenarios.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"213 ","pages":"Article 105353"},"PeriodicalIF":3.0,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064523001030/pdfft?md5=82fcf9dac4aa65d950c232d9a03458f5&pid=1-s2.0-S0967064523001030-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138567154","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":"Mean circulation and its seasonal cycle on the West Florida Shelf as evidenced by multi-decadal time series of moored currents and winds","authors":"Jason A. Law,&nbsp;Robert H. Weisberg,&nbsp;Yonggang Liu,&nbsp;Dennis A. Mayer,&nbsp;Jeffrey C. Donovan","doi":"10.1016/j.dsr2.2023.105346","DOIUrl":"10.1016/j.dsr2.2023.105346","url":null,"abstract":"<div><p>Time series from a moored array of current velocity and surface meteorological sensors, some with record lengths as long as 25 years, are used to describe both the long-term mean circulation and its seasonal variations on the West Florida Continental Shelf (WFS). The moorings are part of the University of South Florida's Coastal Ocean Monitoring and Prediction System (USF-COMPS), a network of ocean observing assets along with numerical circulation models, all used to describe and understand physical and ecological processes on the WFS. These USF-COMPS observations reveal a coherent, shelf-wide mean circulation pattern with depth-averaged flow directed alongshore and down-coast. The vertical structure and the seasonal variations further describe an inner-shelf, wind-driven upwelling region separated from a deeper-ocean influenced offshore downwelling region by a coastal jet. By adding to the record lengths from previous analyses, the statistics are shown to be robust, with the inferences drawn from shorter records being borne out by the present longer-term analyses.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"213 ","pages":"Article 105346"},"PeriodicalIF":3.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0967064523000966/pdfft?md5=a5ef3fed0a0e378b8acf54ec0f9b1355&pid=1-s2.0-S0967064523000966-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135515183","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":"An observing system experiment framework for the tropical Indian Ocean salinity: A case study using a constellation of three satellites","authors":"Smitha Ratheesh ,&nbsp;Neeraj Agarwal ,&nbsp;Rashmi Sharma","doi":"10.1016/j.dsr2.2023.105345","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105345","url":null,"abstract":"<div><p>In this study impact of assimilating Sea Surface Salinity (SSS) from multi-satellites (SMOS, Aquarius and SMAP) on numerical ocean model simulations in the north Indian Ocean has been analysed under the observing system experiment (OSE) framework. Daily data sets of Aquarius, SMAP and SMOS, which were available for a common period of April–May 2015, are used to constrain the ocean model using ensemble optimal interpolation technique. Apart from the control simulation in which satellite data were not assimilated, a total of seven assimilation experiments using different combinations of satellite SSS were conducted. The impact of assimilation experiments is analysed by comparing the model-simulated variables with in situ observations. Assimilating satellite SSS results in a reduction in Root Mean Square Error (RMSE) in SSS (∼ 54%) and also in subsurface salinity (∼ 21%) over the control run. The impact of assimilating SMAP observations is maximum on model simulations with the errors reducing by ∼ 54%. Subsurface salinity improvement is better with three satellites with ∼31% improvement in RMSE in the halocline region, which was ∼11% more than single satellite assimilation. Assimilation of SSS also resulted in improved simulations of the model surface, subsurface temperature and mixed layer depth. Model results show the ability of SSS observations to complement other ocean observation networks. One important observation from this study is that while the impact of assimilating SSS observations from a single satellite was on par with the impact of assimilating SSS observations from two or three satellites in correcting simulated surface salinity, assimilation from more than one satellite had a larger impact in the salinity of deeper layers of the ocean.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"212 ","pages":"Article 105345"},"PeriodicalIF":3.0,"publicationDate":"2023-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91986480","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}