Journal of Marine Systems最新文献

{"title":"Multi-month prediction of summertime hypoxia occurrence in the bottom of Funka Bay, Japan, with a focus on the wintertime surface heat flux","authors":"Chihiro Miki ,&nbsp;Hiroto Abe ,&nbsp;Hiroji Onishi ,&nbsp;Atsushi Ooki ,&nbsp;Tetsuya Takatsu","doi":"10.1016/j.jmarsys.2024.104035","DOIUrl":"10.1016/j.jmarsys.2024.104035","url":null,"abstract":"<div><div>Hypoxic water (&lt; 2 mL of O₂ per L), which can cause mass mortality of demersal fishes, is reported to occur in the enclosed coastal area around the world. Funka Bay, a semi-enclosed and cone-shaped bay with a maximum depth of 107 m, located in the southern part of Hokkaido, Japan, also suffers summertime bottom hypoxic water. Long-term monitoring reveals that the occurrence is greatly variable year by year, yet the controlling factor is still unknown. The present study examined the interannual variability of summertime bottom dissolved oxygen (DO) with the focus on the wintertime heat loss of the water and subsequent convection overturning using year-round moored/ship-board DO observation for the period of 2012–2019. A common feature found in the 8 years was the continuous recovery of bottom DO in winter from the previous summer, which peaked February or March. The first half of the analysis period ceased the DO recovery until February, while one month extension of the DO recovery by March in the second half. The latter tended to show less hypoxia in the following summer as its peak is higher and its DO reduction phase starts later. Wintertime surface heat flux in February created the difference; more heat was lost in the second half because of warmer water temperature under the winter atmosphere. We were successful to predict summertime bottom DO with the accuracy of 0.26 mL/L considering the wintertime heat flux and stratification. This multi-month prediction will be of great help for future fishery activity in Funka Bay.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"247 ","pages":"Article 104035"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143180545","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":"Comments on “Distributions, sea-to-air fluxes, and biological consumption of carbon monoxide in the Bohai and Yellow Seas during winter” by Lin Yang et al., J. Mar. Syst. 2024, 245, 103994","authors":"Dag Myrhaug","doi":"10.1016/j.jmarsys.2024.104025","DOIUrl":"10.1016/j.jmarsys.2024.104025","url":null,"abstract":"","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"247 ","pages":"Article 104025"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179981","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":"Different response of hydrodynamics and near-bottom sediment transport to a cold front in the Changjiang Estuary and its submerged delta","authors":"Xuefeng Wu,&nbsp;Weiming Xie,&nbsp;Naiyu Zhang,&nbsp;Leicheng Guo,&nbsp;Qing He","doi":"10.1016/j.jmarsys.2024.104022","DOIUrl":"10.1016/j.jmarsys.2024.104022","url":null,"abstract":"<div><div>Cold fronts are expected to exert a significant impact on hydrodynamics and sediment dynamics in estuaries, but the exact influence remains insufficiently understood. In this study, we provided an in-depth examination of cold front impact based on a 13-day in-situ observation in the South Passage of the Changjiang Estuary. We deployed two bottom-mounted tripod systems and several buoy stations to collect current velocities, wave heights, wind speeds, near-bottom suspended sediment concentrations (SSC), and bed level changes. Data analyses indicated that the maximum wind speed reached over 20 m/s, with significant wave heights of 1.38 m and 2.66 m inside and outside the South Passage, respectively. Wave-induced bed shear stress predominantly contributed to the total shear stress, and reached up to 0.81 N/m² outside the South Passage. Near-bottom SSC increased by 31 % and 20 % inside and outside the South Passage, respectively, during the post-frontal period, compared to the frontal passage period. The cold front event intensified both the longitudinal circulation in the South Passage and the transverse transport intensity outside the South Passage, leading to a shift in sediment transport direction and landward sediment transport towards the South Passage during the post-frontal period. The cold-front-induced bed shear stress resulted in sediment resuspension in the submerged delta, thereby facilitating a more homogeneous vertical distribution of suspended sediment in the bottom boundary layer. These findings provide insights into the impact of episodic events on water-sediment exchanges at the estuary-ocean interface.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"247 ","pages":"Article 104022"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179982","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":"The instabilities of the Antarctic slope current in an idealized model","authors":"Chengyan Liu ,&nbsp;Zhaomin Wang ,&nbsp;Xi Liang ,&nbsp;Xiang Li ,&nbsp;Xianxian Han ,&nbsp;Wenjin Sun ,&nbsp;Yang Wu ,&nbsp;Xichen Li ,&nbsp;Chen Cheng","doi":"10.1016/j.jmarsys.2024.104034","DOIUrl":"10.1016/j.jmarsys.2024.104034","url":null,"abstract":"<div><div>The Antarctic Slope Current (ASC), coupled with the Antarctic Slope Front (ASF), encircles Antarctica and is a roughly alongshore flow. Yet, the instabilities of the ASC/ASF can induce cross-slope exchanges. The ASC/ASF instabilities have been studied extensively in previous literature. However, the corresponding responsible mechanisms and influences still need to be further clarified. Based on an idealized eddy-resolving model, this study focuses on the instabilities of the ASC/ASF with constant open boundary forcing. The ASC/ASF is classified into three types: Fresh Shelf, Warm Shelf, and Dense Shelf. Focused on the Fresh Shelf and Dense Shelf cases, two high-resolution process-oriented numerical experiments are conducted to reveal the typical characteristics, the dynamic mechanisms, and the influences of instabilities. In the Fresh Shelf case, the instabilities are characterized by a submesoscale vortex train over the middle-lower slope, associated with the Topographic Rossby waves. In the Dense Shelf case, a mesoscale vortex train is present over the lower slope, and abundant filaments and jets can flow across the shelf break. The baroclinic instability greatly contributes to the generation of instabilities in the two cases, yet the barotropic instability contributes less to the instabilities in the Fresh Shelf case. Coherent eddies have been identified and significantly favor the hydrographic anomalies by the advection of water boluses retaining source water rather than the polarities of coherent eddies. Instabilities only contribute to exchanges across the continental rise in the Fresh Shelf case but effectively result in cross-slope exchanges in the Dense Shelf case.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"247 ","pages":"Article 104034"},"PeriodicalIF":2.7,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143179978","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":"Internal tidal dynamics and associated processes at highly supercritical slopes in Banda Sea: Lessons from the oceanic island of Ambon, eastern Indonesia","authors":"Gerry Giliant Salamena ,&nbsp;Jacobo Martín ,&nbsp;Sem Likumahua ,&nbsp;Ferdimon Kainama ,&nbsp;Daniel Deonisius Pelasula ,&nbsp;Intan Suci Nurhati","doi":"10.1016/j.jmarsys.2024.104020","DOIUrl":"10.1016/j.jmarsys.2024.104020","url":null,"abstract":"<div><div>Interactions between the deep sea and steep-sloping oceanic islands generate physical processes with potential impacts on sediment resuspension and ocean productivity. While studies have been conducted in the open oceans, those focusing on oceanic islands of the deep Banda Sea in eastern Indonesia are lacking. Here, we present the first observational evidence of vertical mechanisms (i.e. internal tidal reflection, internal hydraulic jumps) at the highly supercritical slope in outer Ambon Bay (OAB) in Ambon Island – an oceanic island in the Banda Sea. A 23-h CTD yoyo experiment combined with ADCP measurements conducted during spring flood and ebb tides demonstrated tidally-varying vertical temperature, salinity and density profiles. During spring flood tide, incoming internal tides were reflected by OAB's highly supercritical slope back to the deep sea with isopycnals and isotherms showing sharp downward plunges (downward vertical velocity = 6.5–8.3 × 10⁻³ m/s), and the internal tidal amplitude reaching 90–110 m. The reflection during flood tide caused seaward overturning flow at deeper depths despite the prevailing landward flow at the upper layers. During spring ebb tide, internal hydraulic jumps (upward vertical velocity = 6.1–6.48 × 10⁻³ m/s) occurred to rebound the downward plunges of isopycnals and isotherms as flood tide relaxed with the observed amplitude of internal tides of 90 m. We also observed weakened seaward ebb flow during the isothermal uplifting (when hydraulic jumps occurred), and subsequent intensified landward flow at the end of spring ebb tide indicating strong upslope flow when isotherms reached the maximum shoaling depths. Taken together, the observed vertical mechanisms indicate the conservation of energy at the highly supercritical slope of OAB evident by the comparable vertical velocities. An embedded turbidity-chlorophyll profiler in the CTD reveals that internal tidal activities at the highly supercritical slopes OAB may induce bottom nepheloid layers, and influence ocean productivity by regulating the vertical distribution of phytoplankton biomass.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104020"},"PeriodicalIF":2.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578571","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":"Fine-scale phytoplankton community transitions in the oligotrophic ocean: A Mediterranean Sea case study","authors":"Laurina Oms ,&nbsp;Monique Messié ,&nbsp;Jean-Christophe Poggiale ,&nbsp;Gérald Grégori ,&nbsp;Andrea Doglioli","doi":"10.1016/j.jmarsys.2024.104021","DOIUrl":"10.1016/j.jmarsys.2024.104021","url":null,"abstract":"<div><div>The vast diversity of marine phytoplankton, shaped by intricate water dynamics, remains poorly understood in the oligotrophic ocean. <em>In situ</em> studies reveal fine-scale dynamics affecting phytoplankton distribution, leading to abrupt shifts in abundance and biomass referred here as “phytoplankton community transitions” (PCTs). Using a simple nutrient–phytoplankton–zooplankton (NPZ) numerical model, our study proposes a theoretical framework to explain PCTs observed during an oceanographic cruise in the Mediterranean Sea. We consider both a homogeneous and a variable environment, respectively corresponding to the waters on both sides of a front and to the frontal area itself. In the model, PCTs between one community of smaller phytoplankton and one community of bigger phytoplankton are controlled by nutrient supply, but not directly: nutrient supply affects all compartments of the model and creates PCTs by combining bottom-up and top-down controls. This mechanism is observed for both constant (i.e., within a water mass) and pulsed (i.e., in the front) nutrient supply. These results are consistent with <em>in situ</em> observations of biomass proportion across a front. This theoretical framework helps to better understand and plan <em>in situ</em> observations in oceanic regions characterized by fine-scale dynamics and oligotrophic conditions.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104021"},"PeriodicalIF":2.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704490","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":"Summertime nutrient transports in the coastal areas of the Western Northern Yellow Sea","authors":"Chuanxi Xing,&nbsp;Xuefeng Cao,&nbsp;Qian Zhao","doi":"10.1016/j.jmarsys.2024.104018","DOIUrl":"10.1016/j.jmarsys.2024.104018","url":null,"abstract":"<div><div>The summertime nutrient transports in the western Northern Yellow Sea (NYS) have not been well understood due to regional complex physical-biological processes. A coupled model was developed to investigate the summertime nutrient transports in the western NYS. Based on a suite of quantitative skill metrics, the model performance was comprehensively evaluated by comparing the simulated results to a collection of observational data in 2019. The model results were capable of reproducing the observed hydrographical conditions and nutrient distributions in different seasons. In the summer, the coastal areas in the east of Liaodong Peninsula (Zone1) and north of Shandong Peninsula (Zone2) both lost nutrients through cross-boundary nutrient transports for Dissolved Inorganic Nitrogen (DIN) and Dissolved Inorganic Phosphate (DIP). Changes in the surface wind altered the regional circulation and consequently caused variations in nutrient transports for the two zones. Increase in the velocities of southerly wind led to more nutrient losses in Zone1 and less nutrient losses in Zone2. Further sensitivity analysis suggested that the Yalu River was not the dominating factor influencing the nutrient budget of Zone1, and oceanic nutrients contributed around 70 % of the DIN and 99 % of the DIP transported into Zone1. The outflow from Bohai Sea (BS) to NYS dominated the nutrient budget of Zone2. Among the nutrients from the BS, 94.76 % of the DIP were from internal nutrient pool and 3.03 % were from newly input riverine nutrients, those ratios for DIN were 78.79 % and 19.30 %. The Yellow River and Yalu River discharges modulated the regional circulations introducing moderate variations to the nutrient budgets of Zone1 and Zone2.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104018"},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142442331","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":"Variability of inherent optical properties of seawater in relation to the concentration and composition of suspended particulate matter in the coastal Arctic waters of western Spitsbergen","authors":"Sławomir B. Woźniak ,&nbsp;Dagmara Litwicka ,&nbsp;Joanna Stoń-Egiert ,&nbsp;Dariusz Stramski","doi":"10.1016/j.jmarsys.2024.104019","DOIUrl":"10.1016/j.jmarsys.2024.104019","url":null,"abstract":"<div><div>Inherent optical properties (IOPs) and characteristics of suspended particles in surface seawater samples were measured in summer months of 2021 and 2022 in Arctic fjords and coastal waters of western Spitsbergen in the Svalbard archipelago. The measured IOPs included the spectral backscattering and scattering coefficients of suspended particulate matter, as well as the spectral absorption coefficients of suspended particulate matter and its non-algal particulate and phytoplankton components. The particulate assemblages were characterized by measuring the mass concentrations of suspended particulate matter (SPM), particulate organic matter (POM), particulate inorganic matter (PIM), and phytoplankton pigments including chlorophyll-<em>a</em> (Chl<em>a</em>). The investigated coastal waters exhibit high variability of particulate characteristics and associated IOPs. We observed more than two orders of magnitude variation in SPM and particulate IOPs, and Chl<em>a</em> varied from below the detection limit to more than 3 mg m⁻³. The contribution of organic fraction to SPM (POM/SPM ratio) varied from 0.05 to 0.6, and the Chl<em>a</em>/SPM ratio spanned more than three orders of magnitude with a maximum value of the order of 10⁻³. As a result, the mass-specific optical coefficients, especially the mass-specific backscattering and scattering coefficients of particles and mass-specific absorption coefficient of non-algal particulate matter, exhibit large variations. In addition, our study demonstrates the influences of changes in composition of suspended particulate matter parameterized in terms of POM/SPM and Chl<em>a</em>/SPM ratios on IOPs. Various variants of spectral parametrizations of optical coefficients in terms of univariate or multivariable relationships with particulate characteristics are provided. These parameterizations are representative of the investigated coastal Arctic waters in Svalbard region and can be used for better interpretation of optical measurements, both in-situ and remote, in this Arctic environment.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104019"},"PeriodicalIF":2.7,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531220","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":"Modeling the structure changes of cold-water copepods Calanus euxinus population under the influence of the black sea depths deoxygenation","authors":"Elena Vasechkina ,&nbsp;Victor Melnikov","doi":"10.1016/j.jmarsys.2024.104017","DOIUrl":"10.1016/j.jmarsys.2024.104017","url":null,"abstract":"<div><div>The paper presents the results of modeling the possible changes in the structure of the population of <em>Calanus euxinus</em> Hulsemann, 1991 copepods in the Black Sea under the influence of deoxygenation that began in the late 1980s. Over the past 50 years, the depth of oxygen penetration in the deep sea has decreased by almost 50 m. The lower “life limit” of zooplankton in the Black Sea corresponds to the upper boundary of the suboxic layer, where intense copepod aggregation occurs at an oxygen concentration of 10 μM /L. In 1955–1976, this boundary was 130–140 m across the sea, but due to eutrophication and climate change since late 1980s, it has risen in deep water areas to 70–80 m. As a result, the dense copepod layers near the redoxcline and especially their reserve population stock, consisting of non-migrating individuals in diapause, may have been subjected to intensive eating by the Black Sea sprat, which lives to a depth of 100 m and can tolerate hypoxia. To explore this process, we created a new population dynamics model for <em>C. euxinus</em>, which makes it possible to assess changes in the abundance and structure of the population under conditions of a quasi-stationary state and during intensive predation of individuals in diapause. The model describes the dynamics of the <em>Сalanus</em> population based on a statistical description of the relationship between the growth of individuals, their fecundity, the duration of diapause, mortality, and environmental conditions: the concentration of food suspension and temperature in the layer of vertical migration. We put forward the hypothesis that the access of small pelagic fish to the concentration layers of copepods in diapause has a key effect on significant changes in the Black Sea ecosystem, associated with a decrease in the supply of forage plankton and fluctuations in the abundance of pelagic fish.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104017"},"PeriodicalIF":2.7,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427998","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":"Do coastal or equatorial wind anomalies drive the Indian Ocean Dipole?","authors":"Jochen Kämpf","doi":"10.1016/j.jmarsys.2024.104016","DOIUrl":"10.1016/j.jmarsys.2024.104016","url":null,"abstract":"<div><div>Based on first scientific principles, this study shows that both equatorial and coastal wind anomalies influence the development of positive phases of the Indian Ocean Dipole (IOD) in the south-east tropical Indian Ocean (SETIO). While southeasterly winds are favorable for upwelling along Sumatra's southwest coast, zonal equatorial wind anomalies are the main control of IOD variability given that the resultant Kelvin wave enhances or suppresses the Sumatran upwelling. Many previous studies have argued that easterly equatorial wind anomalies in the SETIO are essential for triggering the positive Bjerknes feedback, and thereby, the development of positive IOD (pIOD) events. With a focus on the particularly strong pIOD event of 2019, here we show that pIOD events can also evolve in the absence of zonal equatorial wind anomalies. Hence, it is possible that the Bjerknes feedback along the equator is less involved in IOD variability than previously thought.</div></div>","PeriodicalId":50150,"journal":{"name":"Journal of Marine Systems","volume":"246 ","pages":"Article 104016"},"PeriodicalIF":2.7,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142428000","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}