Local-Scale Variability of Daily Solar Radiation—San Diego County, California

Abstract

The spatial variability of daily solar radiation values over a region of several hundred square kilometers was examined. Coefficients of variability were obtained as the standard deviations of between-station daily radiation difference divided by the mean values for 28 pairs of measuring sites. The coefficient was then plotted as a function of between-station distance. Unlike the results of previous studies undertaken at larger regional scales, no mathematical function could be obtained relating the magnitude of the coefficient to between-station distance. This results from the effect of differences in relief, varying proximity to the coast, and local climatic patterns. The values of the coefficient and the spatial patterns of solar radiation distribution exhibit strong seasonal changes.