Interannual variability of dense shelf water salinities in the north-western Barents Sea

Abstract

The maximum dense shelf water salinity formed during winter in the Svalbard Bank area of the north-western Barents Sea is reconstructed for the period 1952–2000 by analysing the transformation of summer remnants. The variability of 34.7 - 35.4, waters being at the freezing point, is mainly generated by interannual variations in the near surface salinity. On interannual time scales the latter is strongly linked to the sea ice import. In contrast, no correlation of the salinity of the Atlantic Water (AW) throughflow to the Arctic Ocean with the ice import is found. Salinities of both the dense shelf water site in the north-west Barents Sea and the north-eastward AW throughflow show a long term decrease, which can partly be explained by a less saline inflow of AW from the Norwegian Sea. The unusually low dense water salinities in the north-west Barents Sea during the 1990s appear to have a different origin, consistent with a response to oceanic heat advection and decreasing sea ice extent.