Wind- and buoyancy-induced transport of the Norwegian Coastal Current in the Barents Sea

Abstract

The focus of this study is on the fluxes and forcing of the Norwegian Coastal Current (NCC) at the entrance to the Barents Sea. The structure and dynamics of the NCC, which consists of a slope branch and an offshore branch, are investigated using (1) a recent 1 year full depth current meter record in the core of the slope region; (2) repeated hydrographic data at an inshore monitoring station; (3) broader regional hydrographic surveys; and (4) atmospheric reanalysis data. The total fluxes are estimated to 1.8 Sv for volume and 26 mSv for freshwater relative to a reference salinity of 34.8, with the largest contributions from baroclinic offshore branch. The heat flux calculated for the slope branch only is 34 TW. These estimates are higher compared to earlier estimates but are based on more comprehensive data. The major mode of variability in the slope branch is consistent with a continental shelf wave on time scales in the range of 3–16 days forced by the along-coast component of the wind stress. Maximum along-slope currents during fall/winter, corresponding to the stronger wind forcing during these seasons, suggest that the observed seasonality in the NCC can be attributed to a similar mechanism.