PREDICTING THE SPECTRAL AND BROAD-BAND AEROSOL TRANSMITTANCE IN THE ATMOSPHERE FOR SOLAR-RADIATION MODELING

Calculations of the spectral transmittance of the atmospheric aerosol, using Mie theory, for wavelengths between 0 and 40 mu m is presented. The chemical composition of the aerosol particles has been modelled i n order to correspond to the atmospheric conditions of medium and larg e coastal or near coastal cities with important industrial and other a nthropogenic emission sources. Individual size distributions and optic al properties for each aerosol constituent have been considered. Based on the detailed aerosol model, and using parameterization techniques, analytical broadband aerosol transmission functions for the absorptio n and total attenuation are obtained. The accuracy of the proposed exp ressions are verified with various tests, using data from the National Observatory of Athens (NOA). The proposed broadband aerosol transmiss ion functions can be incorporated directly into solar radiation models to predict accurately the beam, diffuse and global solar radiation at a given place. (C) 1997 Published by Elsevier Science Ltd.