Estimating solar radiation in A tropical environment using satellite data

Daily values of satellite derived reflectivity and daily totals of incoming solar radiation were obtained over a six-month period for a network of stations in tropical Queensland, Australia. A definite linear relationship was observed between the reflectivity of the earth-atmosphere system and the atmospheric transmissivity calculated as the portion of extraterrestrial radiation reaching the surface. The scatter in the relationship was largely due to variation in the number of satellite scans available each day and to variations in aerosol absorption. Using the regression model, the transmissivity of solar radiation has been calculated over the entire study region for the months of August 1982 and January 1983. The spatial variability of incoming solar radiation has been discussed. It was found that the spatial pattern is strongly dependent on topography and wind direction.