Estimation of Terrestrial Solar Radiation and its Variation with other Meteorological Parameters over Lokoja, Nigeria

Abstract :

The yearly and monthly estimation of terrestrial solar radiation over Lokoja using meteorological parameters of temperature and relative humidity during the period of twenty two years (July 1983 – June 2005) was investigated. The monthly variation of terrestrial solar radiation with meteorological parameters of global solar radiation, temperature, relative humidity and atmospheric pressure were investigated. The results indicated that high values of terrestrial solar radiation were observed during the rainy season than in the dry season. The highest yearly average values of terrestrial solar radiation observed during the period under investigation were found to be in the year 2005 and 1983 with 378.3521 Wm^(-2) and 368.3232 Wm^(-2) respectively. The highest and lowest monthly values of terrestrial solar radiation were estimated during the rainy and dry seasons in the months of May and January with 385.6133 Wm^(-2) and 358.5111 Wm^(-2) respectively. High values of terrestrial solar radiation with relative humidity and atmospheric pressure were observed during the rainy season and low values during the dry season. The reverse is the case for terrestrial solar radiation with global solar radiation and temperature.