SPATIAL COHERENCE OF SOLAR RADIATION FOR REGIONS IN THE CENTRAL AND EASTERN UNITED STATES

Abstract

Information from the National Climatic Data Center's Solar and Meteorological Surface Observation Network CD-ROM data set is used to study the spatial coherence of incoming solar radiation for selected regions in the United States for the 30-year period 1961–1990. Networks of nine sites are analyzed for each of five regions: North Central, Ohio Valley, New England, East Texas, and Southern Piedmont. The spatial coherence of solar radiation is examined by calculating the standard deviation of daily differences in solar radiation receipt for paired stations and subsequently determining a coefficient of variability. These are plotted as a function of distance between station pairings to establish absolute and relative solar radiation spatial-variation relationships. Comparisons are made among the five regions with the Southern Piedmont showing the most spatial coherence and New England generally having the greatest variation (i.e., greater standard deviation and coefficient of variability values with distance). Interdecade analyses reveal that the relationships are temporally stable, with only slight differences in the three separate decade solar radiation relationships for each region. [Key words: solar radiation, solar climate.]