Measurements of aerosol optical depth at Ispra: Analysis of the correlation with UV-B, UV-A, and total solar irradiance

Aerosol optical depths measured with a Brewer spectrophotometer in the UV r egion and with a CIMEL Sun photometer in the visible and near infrared, bot h in operation at Ispra, Italy, are presented and analyzed. The analysis of the data acquired during 1 year includes a comparison of the spectral aero sol optical depth measured with the Brewer spectrophotometer at various wav elengths, as well as comparisons between the aerosol optical depth measured by the Brewer and the simultaneous measurements taken with the CIMEL Sun p hotometer. The strong correlation between the measurements of aerosol optic al depth obtained from the two instruments demonstrates proper behavior of the instruments and of the methodologies used to retrieve the data. The var iability of global UV-B and UV-A and total solar irradiance is investigated in relation to simultaneous spectral aerosol optical depth measured by the Brewer spectrometer and the CIMEL Sun photometer. The effect of the total ozone column on the correlation between the global UV-B data and the aeroso ls is analyzed.