Solar radiation is or vital interest in characterizing an area with respect to its agricultural potential. However, these are not readily available for a large network. An attempt. has been made to deduce solar irradiance from climatic data, such as temperature range. Based on daily data of Pune for 1986-90, a relationship has been developed between atmospheric transmittance and the daily range of air temperature. The model developed has been tested on independent data and found to give fairly

more »

... ccurate estimation of solar irradiance. Nearly 70% of the variation in daily solar radiation could be explained by this simple method. The effect of solar irradiance on microclimate has also been discussed. The model developed has been tested for Hyderabad and Calcutta and found to give encouraging results.