Modification of Atlantic Water and Lower Halocline Water by Meteoric Water and Sea-Ice Processes along the Siberian Continental Slope

Salinity and stable oxygen isotope (δ¹⁸O) evidence shows that the Atlantic Water inflow into Arctic Ocean is modified by a mixture of sea-ice meltwater and meteoric waters along the Barents Sea continental margin. No further influence of meteoric waters is detectable within the core of the Atlantic Water downstream 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 components by principle component analysis (PCA). All LHW components show the addition of river water and an influence of sea-ice formation to a varying extend. The geographical distribution of LHW components suggest that the high salinity component of LHW forms in the Barents and Kara seas, while further LHW components are formed from south-eastern Kara Sea waters that enter the north western Laptev Sea through Vilkitski 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 a branch continuing along the continental margin and a second branch along the Lomonosov Ridge. While we see no pronounced distinction between onshore and offshore LHW components, the same LHW components that are also found within the halocline over the basin 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 Vilkitski Strait.