On the Relationship between Clear-Sky Planetary and Surfae Albedos

Abstract

Based on simulations, a simple linear relationship is derived between planetary albedo and the surface albedo for the case of clear skies. This relationship enables one to estimate the planetary albedo, given only the surface albedo, and vice versa. The standard error of estimate is 0.028. The estimation of planetary albedo from surface albedo is checked by comparing zonally averaged clear-sky planetary albedos estimated from zonally averaged surface albedos, to satellite determinations of zonally averaged minimum albedos for monthly mean conditions. The minimum albedos are assumed to be representative of the clear-sky planetary albedos. The results show root-mean square differences of 0.05 between the estimated clear-sky planetary albedos and them albedos. More accurate relationships can be obtained if one uses an additional parameter-the solar zenith angle. In this case, the standard errors of estimate are reduced to 0.017 for a zenith angle of 0°,0/018 for a zenith angle of 60° and 0.021 for a zenith of 85°.