Antarctic atmospheric temperature trend patterns from satellite observations

Abstract

Tropospheric temperatures in the Antarctic are retrieved by linearly combining satellite-borne Microwave Sounding Unit (MSU) channels 2 and 4 observations. We show good agreement between satellite-inferred temperature trends and radiosonde observations. It is illustrated that the Antarctic troposphere has cooled in the summer and fall seasons since 1979, in agreement with Thompson and Solomon (2002). It is shown that significant tropospheric warming prevails during Antarctic winters and springs, but we also find significant winter cooling over half of East Antarctica. We find the largest winter tropospheric warming of about 0.6 K/decade for 1979-2005 between 120°W and 180°W. Homogeneous winter tropospheric warming over Antarctica from the ERA-40 reanalysis is not supported by the MSU observations. While MSU stratospheric temperatures exhibit the expected large cooling during the spring and summer seasons, we also find large stratospheric warming over half the southern hemisphere high latitudes in the winter and spring seasons. Copyright 2007 by the American Geophysical Union.