On the accuracy of total ozone measurements made with a Dobson spectrophotometer in Athens

Abstract

Since 1989, total ozone measurements with the Dobson spectrophotometer No. 118 have been made in Athens (38°N, 24°E), which has been suffering from severe air pollution problems during the last fifteen years. These measurements are subject to errors caused by interfering gases that absorb solar ultraviolet radiation in the region of the Dobson instrument's wavelengths (300-400 nm). In the urban area of Athens, the measured S0₂ and N0₂ mixing ratios have been found to lead to total ozone errors of up to 2-5 per cent during the year 1991. To examine the consistency of Dobson measurements, the integrated ozone profiles from a number of ozonesoundings performed at Athens have been used also.