The Quasi-Global Distribution of the Sensitivity of the Earth-Atmosphere Radiation Budget to Clouds

Abstract

Maps are presented showing the mean annual sensitivities of longwave and net radiation at the top of the atmosphere to changes in cloud amount for the region 60°N to 60°S. The maps are based on an analysis of a 45-month set of monthly mean radiation budget data for the years 1974–78 derived from the NOAA satellite scanning radiometers. The analysis technique is based on the regression method of Ohring and Clapp (1980), with some minor modifications. Both regionally and globally, the maps show that the albedo effect of clouds is greater than their greenhouse effect. The maps also suggest that the longwave sensitivity parameter might serve as a useful measure of the geographical distribution of effective cloud heights.