Consistency of global satellite-derived aerosol and cloud data sets with recent brightening observations

Abstract

Solar radiation at the Earth surface has increased over land and ocean since about 1990 (global brightening). An analysis of various global (ocean only) aerosol and (global) cloud data sets from geostationary and polar orbiting satellites is performed to determine whether changes in these quantities have occurred in accordance with global brightening, and to analyse the global distribution of these changes. Change-point detection and trend analysis are employed in the analysis. In a period from the mid-1980s to the mid-2000s, aerosol optical depth is found to have started declining in the early 1990s, while cloud data sets do not agree on trends. ngstrm exponent data seem to suggest changes in pollution. © 2010 by the American Geophysical Union.