STUDYING THE ULTRAVIOLET AND VISIBLE SOLAR-RADIATION OVER CAIRO AND ASWAN AND THEIR CORRELATION WITH CLIMATOLOGICAL PARAMETERS

A study of the hourly, monthly, and annual variations of global and ul traviolet solar radiation and the meteorological parameters over a per iod:of four year (1989-1992) over Cairo (30.05 degrees N, 31-17 degree s E) and Aswan (23.58 degrees N, 32.47 degrees E) in Egypt has been do ne. Measurements were carried out using Eppley ultraviolet radiometers by the Egyption Meteorological Authority. The global solar radiation was recorded using Eppley pyranometers. The correlations between the a tmospheric transmission of ultraviolet solar radiation and clearness i ndex and between ultraviolet and global solar radiation for Cairo and Aswan was also done. The correlations between the different variables by the linear regression analysis to estimate an empirical function re lating global radiation to ultraviolet radiation and-the meteorologica l parameters (temperature, water vapour pressure, and cloudiness) and a comparitive study between Cairo and Aswan has also been\successfully carried out.