Application of Computed Global Radiation for Areas of High Relief

Abstract

The variation over uneven terrain of the daily total of incident shortwave (global) radiation under cloudless conditions may be estimated by existing methods for calculating direct and diffuse solar radiation on a slope. A computer program for performing these calculations, incorporating a technique to determine when the direct rays of the sun are screened by the horizon at each point, is described. The adequacy of the approximation for diffuse radiation is considered by comparison with published data. Computations for an area of east Baffin Island, Northwest Territories, Canada, demonstrate that the occurrence of glaciers there is influenced both by elevation and by solar radiation. The potential of such computations as an aid in selecting station sites for climatological studies is also discussed.