Parameterization of the solar radiative characteristics of low clouds and studies with a general circulation model

A broadband parameterization that improves the quantitative estimates of the solar radiative characteristics of low clouds is developed using reference solutions. The accuracy of the parameterization in determining the shortwave cloud absorption for a wide variety of low-cloud conditions is better than 20%. Other broadband treatments, which do not adequately account for the influences due to above- and in-cloud water vapor and water drop extinction, are also considered to investigate the sensitivity to these factors. General circulation model simulations with fixed sea surface temperatures and cloud amounts further highlight the significance of the vapor and drop optical properties. -from Authors