Estimation of total ozone column over Athens using ground-based beam solar irradiance measurements

The Passive Pyrheliometric Scanner(1) accounts for a tool consisting of both hardware and software. This provides direct solar spectral irradiance measurements analyzed in the range 310-575 nm with a resolution of about 0.5nm. Based on the absorption of solar irradiance in the atmosphere, the total ozone column was calculated for Athens, Greece, in the period February to June 1997. To check the accuracy of the instrument, the estimated total ozone column values are compared with measurements taken by a Dobson spectrophotometer; the comparison shows very good agreement. The apparatus can potentially be employed to calculate NO2 total column with good accuracy.