Insolation over the Arabian Sea during the southwest monsoon

The relationship between monsoon cloud cover and incoming solar radiation in the Arabian Sea is examined utilizing the available observations of daily mean total cloud amount and solar radiation collected during the summer monsoon. With these data sets, various cloud correction formulae are evaluated. For the estimation of solar radiation, the formulation of Laevastu (1960) is best, with a minimum error of -4%. A multiple polynomial regression equation based on cloud cover and noon altitude of the sun is developed for estimation of daily radiation. The error between estimated and observed radiation is -2%.