Why does the upward surface turbulent heat flux resulting from sea ice loss over the Barents and Kara Seas last only for a few days?

Abstract

AbstractThis study explores the reason why strong upward anomalous surface turbulent heat fluxes (STHFs) over the Barents and Kara Seas (BKS) occur for a period of only a few days after wind‐driven sea ice loss, even though anomalously low sea ice persists for more than one month. Composite analysis with ERA5 reanalysis data reveals that the sea ice decline coincides with the poleward advection of warm, moist air on the eastern flank of a synoptic‐scale surface low. This results in the anomalous surface air temperature (SAT) exceeding the anomalous skin temperature (SKT) and a downward anomalous STHF. As the surface low propagates eastward, the wind direction changes, resulting in the advection of cold, dry air, the anomalous SKT exceeding the anomalous SAT and a brief period with a strong upward anomalous STHF. This period of strong upward anomalous STHF is cut short, as the surface low propagates southeastward out of the BKS. The eastward propagation of the surface low is crucial, as it allows for northward driving of sea ice to be followed by cold advection and a strong upward anomalous STHF. These results indicate that when wind‐driven sea ice motion exposes the ocean to the atmosphere, except for a brief episode, the reduction of sea ice does not coincide with an increase in a strong upward anomalous STHF.