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

{"title":"Near-inertial oscillations in the deep Gulf of Mexico","authors":"Yingli Zhu,&nbsp;Xinfeng Liang","doi":"10.1016/j.dsr2.2023.105310","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105310","url":null,"abstract":"<div><p>Near-inertial oscillations (NIOs) are important for maintaining turbulent mixing that affects ocean circulation, biogeochemistry<span>, and climate. The spatial and temporal variability of NIOs in the deep part of the Gulf of Mexico<span> (GoM) has rarely been reported. In this study, a collection of moored current observations was used to examine the spatiotemporal variability of NIOs in the GoM. In the upper layer (0–800 m), a strong seasonal variability of NIOs appears in the eastern GoM with larger amplitudes in winter than in summer and is attributed to the seasonal variability of surface winds and mixed layer depth. In the bottom layer (within 400 m above the bottom), strong NIOs are found in the middle and eastern GoM and show weaker seasonal variability. While winds still matter for the seasonal variability of NIOs in the bottom layer in the eastern GoM, low-frequency flows generally play a more important role in regulating NIOs through interactions with topography, particularly on the continental slope.</span></span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"210 ","pages":"Article 105310"},"PeriodicalIF":3.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50194587","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":"Seeps and vents of the Bering Sea","authors":"Vladimir V. Mordukhovich,&nbsp;Elena M. Krylova,&nbsp;Paul R. Dando","doi":"10.1016/j.dsr2.2023.105290","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105290","url":null,"abstract":"","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105290"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174438","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":"Record-breaking 2020 summer marine heatwaves in the western North Pacific","authors":"Yulong Yao ,&nbsp;Chunzai Wang ,&nbsp;Chao Wang","doi":"10.1016/j.dsr2.2023.105288","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105288","url":null,"abstract":"<div><p><span><span>Record-breaking marine heatwaves (MHWs) occurred in the western North Pacific during the summer of 2020. These unprecedented MHWs were consistent with favorable large-scale conditions that are linked to an anomalous western North Pacific subtropical high (WNPSH), resulting mainly from sea surface temperature (SST) anomalies across the tropical oceans. In addition, a moderate La Niña-like pattern was also conducive to transporting warm seawater to the western North Pacific. Mixed-layer heat budgets suggest that surface heat flux contributed to the SST anomaly in the western subtropical Pacific. In contrast, oceanic heat </span>advection dominanted in the South China Sea and the western equatorial Pacific. Numerical model experiments indicated that the tropical Indian Ocean SST anomalies were responsible for the enhanced WNPSH. The increased zonal SST gradient across the tropical Pacific also played an important role. Inter-ocean interactions can modulate </span>climate variability<span><span> through ocean-atmospheric coupling and deserve more attention when predicting MHWs within the context of global warming. In addition, it is critical to consider MHWs as a powerful tool in detecting acute, intense thermal stress events in the </span>coral bleaching pre-warning system.</span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105288"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174423","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":"Cause and impact of Andaman Sea's salinity variability: A modeling study","authors":"Abhishek Pasula,&nbsp;Deepak N. Subramani","doi":"10.1016/j.dsr2.2023.105291","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105291","url":null,"abstract":"<div><p>The Andaman Sea is an important and strategic region for India, both from a security and conservation viewpoint. Documenting the spatiotemporal variability of salinity<span> is fundamental to understanding this region's dynamics. We studied the Andaman Sea's seasonal and inter-annual salinity variability during the Boreal summer (JJAS) using NEMO reanalysis data (1993–2018). Analysis of river influx, precipitation, Empirical Orthogonal Functions<span> of the salinity fields, numerical particle trajectory experiments, and statistical significance tests were conducted to understand the causal factors and impact of the Andaman Sea's salinity variability. Our study shows that it is the Southwest Monsoon Current (SMC) that brings a significant influx of salinity into the Andaman Sea and governs the seasonal cycle. We also document and explain the different surface and sub-surface dynamical trends. We show that higher salinity influx to the Andaman Sea is correlated with the strength of SMC. Crucially, this study is the first-ever attempt to comprehend the salinity dynamics of the Andaman Sea utilizing both Empirical Orthogonal Function (EOF) analysis and particle trajectories. We also note the reported reduction in shark catch and qualitatively analyze its relation to the seasonal salinity cycle, motivating the need for further physical-biological combined studies of the region.</span></span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105291"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174427","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":"Seasonal Indonesian Throughflow (ITF) across southern Java determines genetic connectivity of Sardinella lemuru (Bleeker, 1835)","authors":"A. Sartimbul ,&nbsp;V.A. Winata ,&nbsp;R.D. Kasitowati ,&nbsp;F. Iranawati ,&nbsp;E. Rohadi ,&nbsp;D. Yona ,&nbsp;U.G. Anjeli ,&nbsp;W.S. Pranowo ,&nbsp;F.M. Lauro","doi":"10.1016/j.dsr2.2023.105295","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105295","url":null,"abstract":"<div><p><em>Sardinella lemuru</em> populations are considered near-threatened in Bali Strait. Despite declining fish stock, documented landings of <em>S. lemuru</em> at the Prigi waters unexpectedly climbed during the 2nd transitional inter-monsoon season of 2019. Here we used a combination of molecular taxonomy and morphometrics-meristics to determine the genetic link between <em>S. lemuru</em> populations in East Java's southern seas (Prigi and Puger) and those in the Philippines. The results of both molecular and morphometric-meristic analyses suggest that extensive genetic mixing between the populations from Prigi and the Philippines is occurring. Most samples clustered with the <em>S. lemuru</em> populations from the Philippines in Clade-1 and Haplogroup A and B implied high genetic connectivity. The inferred patterns of haplotype network and haplogroup relative frequency indicate the dispersal, genetic homogeneity, and absence of geographical barriers between <em>S. lemuru</em> populations were also supported by a seasonal model of ocean circulation: during the southeast monsoon, greater Indonesian Through-Flow and South Java Current, followed by westward currents along Java's south coast. The findings of this study give much-needed evidence that <em>S. lemuru</em><span> populations disperse to a secondary fishing area (in Prigi waters), followed by high plankton abundance in 2019, as a result of ITF<span> and local seasonal circulation. The unique sequences of Puger-2017 and the remainder of Prigi-2017 in Clade-2 with overall moderate genetic distance separated from Clade-1 because the Puger water mass are influenced by the Java Sea and Madura Strait or possibly migrated from their habitats in the western part of Indonesia or the Java Sea.</span></span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105295"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174439","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 imbalance in organic carbon budgets is indicative of a missing vertical transfer during a phytoplankton bloom near South Georgia (COMICS)","authors":"S.L.C. Giering ,&nbsp;R. Sanders ,&nbsp;S. Blackbird ,&nbsp;N. Briggs ,&nbsp;F. Carvalho ,&nbsp;H. East ,&nbsp;B. Espinola ,&nbsp;S.A. Henson ,&nbsp;K. Kiriakoulakis ,&nbsp;M.H. Iversen ,&nbsp;R.S. Lampitt ,&nbsp;K. Pabortsava ,&nbsp;C. Pebody ,&nbsp;K. Peel ,&nbsp;C. Preece ,&nbsp;K. Saw ,&nbsp;M. Villa-Alfageme ,&nbsp;G.A. Wolff","doi":"10.1016/j.dsr2.2023.105277","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105277","url":null,"abstract":"<div><p>The biological carbon pump, driven principally by the surface production of sinking organic matter and its subsequent remineralization to carbon dioxide (CO₂) in the deep ocean, maintains atmospheric CO₂ concentrations around 200 ppm lower than they would be if the ocean were abiotic. One important driver of the magnitude of this effect is the depth to which organic matter sinks before it is remineralised, a parameter we have limited confidence in measuring given the difficulty involved in balancing sources and sinks in the ocean's interior. One solution to this imbalance might be a temporal offset in which organic carbon accumulates in the mesopelagic zone (100–1000 m depth) early in the productive season before it is consumed later. Here, we develop a novel accounting method to address non-steady state conditions by estimating fluxes of particulate organic matter into, and accumulation within, distinct vertical layers in the mesopelagic zone using high-resolution spatiotemporal vertical profiles. We apply this approach to a time series of measurements made during the declining phase of a large diatom bloom in a low-circulation region of the Southern Ocean downstream of South Georgia. Our data show that the major export event led to a significant accumulation of organic matter in the upper mesopelagic zone (100–200 m depth) which declined over the following weeks, implying that temporal offsets need to be considered when compiling budgets. However, even when accounting for this accumulation, a mismatch in the vertically resolved organic carbon budget remained, implying that there are likely widespread processes that we do not yet understand that redistribute material vertically within the mesopelagic zone.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105277"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174485","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":"Atmospheric and advective forcing of upwelling on South Africa's central Agulhas Bank","authors":"Lisa Hancke ,&nbsp;David Smeed ,&nbsp;Mike Roberts ,&nbsp;Cristina Russo ,&nbsp;Darren Rayner ,&nbsp;Fatma Jebri","doi":"10.1016/j.dsr2.2023.105293","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105293","url":null,"abstract":"<div><p>Current and temperature structures on South Africa's central Agulhas Bank are described from six months of moored observations and ancillary data collected during the seasonal transition from austral spring to summer (October 2018–March 2019). The occurrence of an intermittend mid-shelf upwelling ridge, associated with increased productivity, is an important part of the shelf's thermal structure. However, the subsurface evolution of this cold ridge has not been documented to date. A mooring array that transected the wide central shelf captured the seasonal increase in stratification that culminated in the formation of a cold ridge in late summer. We show that the cold ridge originates in the wind-driven upwelling zone on the eastern Agulhas Bank and emphasise the importance of oceanic forcing in maintaining the subsurface thermal structure through advective steering of wind-driven coastal upwelling plumes and through dynamic shelf edge upwelling. The main source of the cold basal layer at the mooring transect originated from upwelling further east, but persistent near-seabed temperatures &lt;9 °C on the outer shelf during the encroachment of the Agulhas Current confirm the contribution of shelf edge upwelling, offshore of the mooring transect, to the cold bottom layer on the Agulhas Bank. Of particular interest is the strengthening of the south-westward shelf current, inshore of cyclonic flow in the Agulhas Bight that accelerated the offshore advection of productive coastal water in the shape of the cold ridge. We show the shelf circulation to be highly coherent across and along the shelf. Shelf-wide barotropic pulses were driven by increased zonal wind stress that was in turn associated with variation in coastal sea level. In the light of global climate change, this work highlights the importance of long term in-situ monitoring in understanding ecosystem functioning on the highly dynamic Agulhas Bank.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105293"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174426","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":"Causal relations between the loop current penetration and the inflow/outflow conditions inferred with a rigorous quantitative causality analysis","authors":"Yang Yang ,&nbsp;Guanqi Fu ,&nbsp;X. San Liang ,&nbsp;Robert H. Weisberg ,&nbsp;Yonggang Liu","doi":"10.1016/j.dsr2.2023.105298","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105298","url":null,"abstract":"<div><p>The causal relationship between the Loop Current (LC) penetration into the Gulf of Mexico and the inflow/outflow conditions in the Yucatan Channel and the Straits of Florida is analyzed using a recently developed causality analysis, which is quantitative in nature, and rigorously derived from first principles. Long-term time series from a 23-year high-resolution reanalysis product reveals that the LC penetration is associated with a dipole (tripole) mode of transport (vorticity flux) in both channels. These relationships, though significant from a perspective of correlation, do not necessarily imply causality. By applying the causality analysis, we identify a clear asymmetry of causality, that is, the flow conditions in the Yucatan Channel and the Straits of Florida can both cause the LC penetration. Conversely, the LC path state is less causal to the current variability in the two channels. The spatial causal structures further reveal that the upstream influence from the Yucatan Channel is strong in the main body of the LC as well as its extension area, while the downstream influence from the Straits of Florida is confined within the eastern branch of the LC. The asymmetric causal relations obtained from the data-assimilative reanalysis product are further confirmed in a free-running model simulation forced by three repeated cycles of atmospheric forcing, although the strength of the causality could vary from one simulation cycle to another, due to the intrinsic variability of the LC system.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105298"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174424","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":"Trend of annual and semiannual harmonics of sea surface temperature in the tropical Indian Ocean, 1979–2018","authors":"V.A. Abhishek,&nbsp;V. Vijith,&nbsp;N. Anup","doi":"10.1016/j.dsr2.2023.105292","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105292","url":null,"abstract":"<div><p><span><span><span>In the Indian Ocean (IO), the annual and semiannual oscillations of the </span>sea surface temperature<span> (SST) contribute more than 80% of the total variance. It is known that the SST in the tropical IO has warmed at a rate of 0.15 °C/decade since 1979. However, such an estimate of the decadal trend of the annual and semiannual harmonics of SST remains unknown, despite being a strong component of the SST signal. Here we use a widely accepted data product (TropFlux) to quantify the annual and semiannual harmonics in the tropical IO for the first time. The northern IO has a distinctly strong semiannual cycle (1–1.8 °C), which is showing an amplifying trend (∼ 0.04 °C/decade) since 1979. Furthermore, a damping trend in annual amplitude exists over much of the IO, except along the northwestern Bay of Bengal, the Seychelles-Chagos thermocline ridge, the </span></span>Persian Gulf, and the Indonesian </span>throughflow<span><span><span> region. The estimated damping of the annual amplitude is highest over the Arabian Sea. In contrast, the southern tropical IO has a predominant annual cycle, the amplitude of which has weakened during 1979–2018. In the north IO, net air-sea heat flux and vertical processes show a dominant semiannual harmonic oscillation similar to SST. Additionally, the annual amplitude is influential over southern IO. Horizontal </span>advection contributes significantly along the boundary-current regions and the western equatorial IO. Our analysis of combined annual and semiannual cycles shows significant warming in the tropical IO during October–November and cooling during July–August owing to the amplification of semiannual oscillation. These changes in the SST can influence air-sea interaction processes such as </span>cyclogenesis and monsoon.</span></p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105292"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174425","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":"Forecasts of marine heatwaves for marine industries: Reducing risk, building resilience and enhancing management responses","authors":"Jason R. Hartog ,&nbsp;Claire M. Spillman ,&nbsp;Grant Smith ,&nbsp;Alistair J. Hobday","doi":"10.1016/j.dsr2.2023.105276","DOIUrl":"https://doi.org/10.1016/j.dsr2.2023.105276","url":null,"abstract":"<div><p>Ocean use has always been risky because of uncertain and dramatic ocean conditions and modern businesses continue to experience risk due to environmental extremes. A changing physical environment due to anthropogenic climate change and increased frequency of extreme events such as marine heatwaves makes past experience less valuable. This risk can be reduced by utilising seasonal forecasts that provide early warning of climate events several months ahead of time. However, to benefit from a forecast, a marine business will need to be agile to respond to changing information and response options. We define a set of seven attributes that can influence and enhance this management agility; leadership, social expectations, signal strength, system manipulation, regulatory environment, market forces, and value of the operations. The management agility of different marine businesses in fisheries, aquaculture, and tourism can influence their ability to use seasonal forecast information effectively, and potentially modify the usual negative relationship between resilience and the frequency of the stress event, thus reducing the impact of extreme events. Engagement between forecast developers and marine users can also improve responses, while at the same time, improving the agility of businesses can enhance overall resilience to extreme events and lower their risk.</p></div>","PeriodicalId":11120,"journal":{"name":"Deep-sea Research Part Ii-topical Studies in Oceanography","volume":"209 ","pages":"Article 105276"},"PeriodicalIF":3.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50174440","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}