A Surface Solar Radiation Model for Cloudy Atmospheres

Abstract

A numerical solar radiation model based on standard meteorological data was revised for clouds using data from the GARP Atlantic Tropical Experiment (GATE). Climatic-mean transmittance functions were revised for low and convective clouds independent of zenith angle. Transmittance during partial cloudiness ψc was assumed to vary from the climatic-mean transmittance during overcast skies &ψmacr; by ψc = &ψmacr;c where c is the cloud amount. Mean errors in computed flux as a function of cloud amount were reduced. Results for four GATE ships are presented.