A global signature of enhanced shortwave absorption by clouds

Satellite observations of visible and near-infrared radiation reflected by the ocean and atmosphere are compared to fluxes calculated with a general c irculation model. The satellite data and model simulation are global and ex tend from 1979 to 1987, Under clear-shy conditions, the observed and modele d spectral albedos are nearly identical. The observations and simulations d iverge with increasing cloud albedo and cloud amount, regardless of cloud t ype or cloud phase. The differences between the model and the satellite dat a occur for all tropical and midlatitude ocean regions and exhibit minimal seasonal and interannual variability. These results are consistent with enh anced absorption of shortwave radiation by clouds relative to models of rad iative transfer.