Influence of the gasous atmosphere on solar fluxes of inhomogeneous clouds

The influence of spatially inhomogeneous water vapour distributions on the solar radiative fluxes of inhomogeneous clouds has been estimated by means of Monte Carlo radiative transfer calculations and line by line calculations for transmission at water vapour and oxygen. 96 cloud realizations obtained by the atmospheric model GESIMA have been considered for the following cases: 1) Clouds embedded in a 3d inhomogeneous gas atmosphere and 2) clouds embedded in a stratified gas atmosphere. The resulting differences in solar broadband radiative fluxes appear to be neglectable. Thus, a stratified gaseous atmosphere seems sufficiently adequate for solar radiative transfer calculations. The reasons for these small differences are basically due to the strong correlation between cloud optical thickness and water vapour density as produced by the cloud model used in this study