Regional Fingerprints and Energy Budget Analysis of Southern Hemispheric Warming

The detailed regional fingerprints of Southern Hemispheric warming are investigated by using the ERA-20C (20th century) reanalysis data. The warming signal is most conspicuous in winter with an arc-like surface warming structure along the sea ice perimeter around the Antarctica. Other surface variables such as turbulent heat flux, and longwave and shortwave radiation exhibit similar spatial patterns. A detailed energy budget analysis indicates that the net energy increase over the region of winter sea ice reduction (30°W–80°E, 50°–60°S) exceeds 5 W m^-2 in August–November during the last century. This net energy increase is caused mainly by the increased absorption of shortwave radiation by the decreased albedo owing to the reduction of sea ice and the increased absorption of longwave radiation by the increased specific humidity in the atmospheric column. Prospect of Southern Hemispheric warming based on the detailed energy budget analysis will be presented.