Coupled oscillations in Antarctic sea ice and atmosphere in the South Pacific sector

Abstract

Interannual oscillations with period of about 3-6 years have dominated the winter atmospheric and ice variability in the Ross, Amundsen, and Bellingshausen Seas, Antarctica, during 1979-1998. Anomalies in sea ice concentration and drift propagate eastward in the winter ice pack, coupled to sea level pressure anomalies. This signal accounts for the ice and atmospheric components of the Antarctic Circumpolar Wave during its eastward passage through the Pacific sector of Antarctica. Sea ice concentration anomalies at the ice margin seem to result from air-ice-sea interactions which involve both the dynamic effect of the anomalous, wind-driven ice motion, and the thermodynamic ice growth and melting due to surface air and ocean temperature anomalies.