On the relationship between clearsky planetary and surface albedos: a parameterization for simple energy balance climate models
Abstract
In simple energy balance climate models all physical and dynamical processes are parameterized in terms of the single unknown variable: the surface temperature. To simulate the icealbedo feedback, the surface albedo is usually assumed to be a function of surface temperature. But to compute the absorbed solar radiation in such models one requires the topofthe atmosphere albedo: the planetary albedo. In the present study, a simple linear relationship is derived between planetary albedo and surface albedo for the case of clear skies. The relationship is based upon a regression equation derived from simulations and has a standard error of estimate of 0.028. The estimation of planetary albedo from surface albedo is checked by comparing zonally averaged clearsky 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 clearsky planetary albedos. The results show rootmean square differences of 0.05 between the estimated clearsky planetary albedos and the minimum 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 angle of 85°.
 Publication:

Advances in Space Research
 Pub Date:
 1985
 DOI:
 10.1016/02731177(85)903126
 Bibcode:
 1985AdSpR...5f.141C