Seasonal ice removal in the Barents Sea and its dependence on heat advection by Atlantic waters

Abstract

The Barents Sea is one of the key areas in the Arctic for monitoring of climate change. Although the Barents Sea is one of the Arctic seas, it is never completely covered with ice. One of the parameters characterizing the change in the ice regime is the date of ice retreat (DOR). The study is based on ice concentration data from the NOAA / NSIDC Climate Data Record (CDR) from 1979 to 2019 and the GLORYS12V1 ocean reanalysis data from 1993 to 2019. The analysis of the spatial and temporal variability of DOR for the Barents Sea using the HDBSCAN cluster analysis method made it possible to identify areas (clusters) with the synchronous dynamics of DOR. A number of the identified areas are located on the path of the Atlantic waters (AW) in the Barents Sea, which made it possible to relate the revealed temporal variability of the DOR to the variability of the AW transport across the western boundary of the sea. Over the entire Barents Sea, after 2003, there has been a steady trend in the timing of seasonal ice removal to earlier ones. At the same time, each of the six regions identified has its own dynamics and rate of changes in DOR. A noticeable effect of the advective heat flux across the western boundary of the Barents Sea on the DOR was revealed for areas in the central and eastern parts of the sea. At the same time, for different regions, the maximum correlation coefficient is observed at different time lags (from 0 to 6 months). The value of the time lag indirectly indicates the time the thermal signal travels the distance from the western boundary of the sea to the corresponding region. The continuing trend towards an increase in the duration of the ice–free season in the Barents Sea is one of the manifestations of the growing “Atlantification” of the East Atlantic sector of the Arctic Ocean which opens up new prospects for socio–economic activity in this Arctic region.