Shelf basin exchange along the Siberian continental margin: modification of Atlantic Water and Lower Halocline Water

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Bauch, Dorothea, Cherniavskaia, Ekaterina, Timokhov, Leonid
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Arctic; Arctic Ocean; Barents Sea; Kara Sea; Laptev Sea; laptev; Lomonosov Ridge; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/33300/; https://oceanrep.geomar.de/id/eprint/33300/1/Bauch%20et.al.pdf; https://oceanrep.geomar.de/id/eprint/33300/7/Bauch.pdf; https://doi.org/10.1016/j.dsr.2016.06.008

Highlights • Atlantic Water modified by sea-ice melt and meteoric water at Barents Sea slope • LHW may be divided into different types by Principal Component Analysis (PCA) • high salinity LHW-type forms in the Barents and Kara seas • low salinity LHW-types form in the western Laptev Sea or enter via Vilkitsky Strait • PCA does not support a distinction between onshore and offshore LHW branches Abstract Salinity and stable oxygen isotope (δ18O) evidence shows a modification of Atlantic Water in the Arctic Ocean by a mixture of sea-ice meltwater and meteoric waters along the Barents Sea continental margin. On average no further influence of meteoric waters is detectable within the core of the Atlantic Water east of the Kara Sea as indicated by constant δ18O, while salinity further decreases along the Siberian continental slope. Lower halocline waters (LHW) may be divided into different types by Principal Component Analysis. All LHW types show the addition of river water and an influence of sea-ice formation to a varying extent. The geographical distribution of LHW types suggest that the high salinity type of LHW forms in the Barents and Kara seas, while other LHW types are formed either in the northwestern Laptev Sea or from southeastern Kara Sea waters that enter the northwestern Laptev Sea through Vilkitsky Strait. No further modification of LHW is seen in the eastern Laptev Sea but the distribution of LHW-types suggest a bifurcation of LHW at this location, possibly with one branch continuing along the continental margin and a second branch along the Lomonosov Ridge. We see no pronounced distinction between onshore and offshore LHW types, as the LHW components that are found within the halocline over the basin also show a narrow bottom-bound distribution at the continental slope that is consistent with a shelf boundary current as well as a jet of water entering the western Laptev Sea from the Kara Sea through Vilkitsky Strait.