Abstract
The Barents Sea is one of the main pathways for warm and saline Atlantic
Water (AW) entering the Arctic Ocean. It is an important region for
water mass transformation and dense-water production that contribute to
the Atlantic meridional overturning circulation. Here, we present data
from three cruises and nine glider missions conducted between 2019 and
2022 in the western Barents Sea, and compare with historical data
collected from 1950 to 2009. We present circulation pathways,
hydrography, heat content and volume fluxes of Atlantic- and
Arctic-origin waters. Our observations show that 0.9±0.1 Sv (1 Sv = 106
m3 s-1) of Atlantic-origin water reaches the Polar Front (PF) region
before splitting into several branches and eventually subducting beneath
Polar Water (PW). The observed increased heat content in the AW inflow
over the past decades can be traced under the Polar front. The amount of
heat stored in the basin north of the PF is determined by the density
difference between AW and PW, and reached a maximum in the 90s when PW
was particularly fresh. The inflow of Atlantic Water (AW) into the
Barents Sea during the period from 2019 to 2022 exhibits a decrease in
salinity of up to 0.1 g kg-1 compared to previous decades. Consequently,
this leads to a reduction in the production of dense water, an increased
temperature gradient across the PF, and a reduced poleward transport of
warm water.