Measurement of Ultra-Violet (UV) Solar Radiation

The intensity of the UV solar radiation has strong dependency on the Aerosol Optical Thickness (AOT). The UV solar radiation on earth depends on geometrical factors such as altitude, latitude, solar zenith angle and other atmospheric parameters. In this work, an attempt has been made to study the variation of the intensity of UV solar radiation with time for the period of three months. The UV solar radiation measured was compared with AERONET Aerosol Optical Thickness (AOT) values at two discrete wavelengths of 340nm and 380nm for Ilorin located in the North Central part of Nigeria (8o30'N, 4o33'E). The correlation between mean daily values of both is to test the possibility of estimating AOT from AERONET AOT data by comparing with the raw UV solar radiation data measured by PACE UV sensor which is a different instrument at Ilorin station. A fair correlation value of 0.59 was obtained for the period of May to July, 2014 for the wavelengths 340nm and 380nm wavelengths. The slopes, and intercepts were (-2.77, 5.91) and (-3.00, 5.97) for 340 nm and 380 nm respectively Using the obtained slope and intercept, AOT values were estimated from the UV radiation measurement.