Tropospheric response in the Antarctic circumpolar wave along the sea ice edge around Antarctica

Abstract

The Antarctic circumpolar wave (ACW) signal of a 3.7-yr period occurs along the sea ice edge forming around Antarctic each fall-winter-spring from 1982 to 2001. It was larger during the first decade than the second and has retracted sea ice extent (SIE) anomalies coinciding with warmer sea surface temperature, greater upward latent heat flux, and higher precipitation, driving deep convection in the troposphere associated with low-level convergence and upper-level divergence. Lower sea level pressure is displaced ∼90° of phase to the west of retracted SIE anomalies, coinciding with increased extratropical cyclone density and intensity. The authors diagnose tropospheric thermal and potential v..