Abstract

Since 1979 Antarctic sea ice extent has increased throughout the year, with the total Antarctic annual mean extent having increased at a rate of 1.5% per decade. However, this overall increase masks large regional variations and especially an increase (decrease) over the Ross (Amundsen-Bellingshausen) Sea. The mechanism or mechanisms responsible for the increase in Antarctic SIE are not fully understood, but the loss of stratospheric ozone, freshwater injection from the ice sheet, ocean-ice feedback processes and ocean change have all been put forward as possibly playing a part. But the observed ice increase is dominated by change in the Ross Sea where the ice extent is significantly correlated with the state of the Amundsen Sea Low, which has deepened in recent decades. However, the atmospheric circulation changes and sea ice increase may be within the bounds of internal variability of the climate system.