Changes of atmospheric warming associated with rapid sea ice loss events on the synoptic time scale in winter

Abstract

This study examines how the Arctic warming during rapid sea ice decline changes over Barents-Kara Seas (BKS) on the synoptic time scale in winter. We divide the satellite record 1979–2024 into two time periods: 1979–2002 (P1) and 2003–2024 (P2), with a focus on the difference between P1 and P2. A rapid sea ice loss event is defined, when the sea ice tendency index falls below the 5th percentile of the corresponding P1/P2 time series for at least three consecutive days. Composite analysis shows that the negative center of sea ice concentration anomaly for rapid sea ice loss events in P2 shifts more northward compared to P1, consistent with the retreat of Arctic sea ice edge due to global warming. Climate change influences the position and structure of atmospheric anticyclonic anomaly over BKS associated with rapid sea ice loss, which makes the maximum adiabatic cooling in the upper troposphere shift to mid-troposphere and enhances the horizontal temperature advection, particularly in the meridional direction near the surface. Consequently, the positive atmospheric temperature anomaly intensifies, with the maximum at 800 hPa shift to the surface, despite enhanced diabatic cooling in the lower troposphere over BKS. This study underscores the significance of enhanced warm horizontal temperature advection with bottom amplified on the surface warming during rapid sea ice decline in the recent decades. As a result, the positive skin temperature anomaly is also magnified, which is due to increased downward longwave radiation resulting from increased atmospheric temperature and moisture over BKS.