The connection between sea ice dynamics enhancement and atmospheric circulation in the East Siberian Sea during spring

Abstract

The change in sea ice thickness can be divided into dynamical and thermodynamical effect. In the last four decades, the drastic changes in multi-year ice thickness in East Siberian Sea during spring have made the sea ice more susceptible to dynamical effect. On one hand, the dynamical effect on sea ice in this region is the strongest, surpassing that of other Arctic marginal seas, and has been continuously strengthening since 1996. On the other hand, this region’s dynamical effect varies with the Central Arctic Index (CAI). An increase in CAI extreme positive phase years leads to more frequent occurrences of cyclonic circulation anomalies, favoring the development of dynamical effect in spring East Siberian Sea. Furthermore, the influence of 10 m wind field on dynamical effect has shifted from being dominated by the northward component (v) to a combined effect of both northward and eastward components (v and u). This change is a result of alteration in the response pattern of wind field to CAI across the interdecadal periods.