Observation and Attribution of Temperature Trends near the Stratopause from HALOE

This study considers temperature time series from the Halogen Occultation Experiment (HALOE) across the stratopause region, where the effects of radiative forcings from the greenhouse gases and from ozone are most pronounced. HALOE data time series are for 1993-2005, or when the trends in ozone are slightly positive. The trend analyses make use of profile data having a vertical resolution of about 4 km, and they are for seven pressure levels from 3.0 to 0.3 hPa and at eight latitude zones from 60°S to 60°N. The near-global trend profile derived from the analysis exhibits a minimum cooling rate of about -0.1 K/decade at 1.0 hPa; the analyzed cooling rates are larger in the upper stratosphere and lower mesosphere. The overall character of this temperature trend profile from HALOE is opposite to those calculated and observed for 1980-2000. To first order, the difference is a result of the changing trends for ozone in the uppermost stratosphere during the time span of HALOE.