Atmospheric forcing of the Beaufort Sea ice gyre: Surface‐stratosphere coupling

In a companion article we examined the nature of correspondence between synoptic weather patterns and reversals in the Beaufort Sea ice gyre. In this paper we extend this analysis to examine the role of stratospheric forcing on surface phenomena. Investigated in particular is the correspondence between reversals in stratospheric winds at 10 mbar during winter as defined by stratospheric sudden warmings (SSW) and mean sea level pressure synoptic types in the Beaufort Sea region. Connections between stratospheric and surface events are characterized using relative vorticity and the square of strain computed at different pressure levels from the stratosphere to the surface in the Beaufort Sea region. We quantify the correspondence between stratospheric flow and surface phenomena through investigation of the frequency in synoptic types derived in a companion article during stratospheric sudden warming events. Investigation of stratospheric wind gradients averaged over the Beaufort Sea region demonstrates a prevalence in anticyclonic activity during SSWs that persists for approximately 20 days. Examination of the evolution in synoptic types in the Beaufort Sea region also shows an increase in the number of synoptic types associated with anticyclonic activity during SSWs.