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 circulation model. The satellite data and model simulation are global and extend from 1979 to 1987. Under clear-sky conditions, the observed and modeled spectral albedos are nearly identical. The observations and simulations diverge with increasing cloud albedo and cloud amount, regardless of cloud type or cloud phase. The differences between the model and the satellite data occur for all tropical and midlatitude ocean regions and exhibit minimal seasonal and interannual variability. These results are consistent with enhanced absorption of shortwave radiation by clouds relative to models of radiative transfer.