Sensitivity of surface UV radiation and ozone column retrieval to ozone and temperature profiles

This paper discusses the influence of ozone and temperature profiles on sur face UV radiation, and on total ozone column derived from global irradiance measurements. Measured ozone and temperature profiles from Legionowo, Pola nd, are used together with typical surface and cloudless atmosphere conditi ons. The effects of assuming a U.S, standard profile with scaled ozone colu mn instead of actual profiles are analyzed. Variable temperature/ozone vert ical distributions and different sets of ozone absorption cross section dat a may change erythemally weighted radiation by as much as 14% with respect to reference conditions. The mean and standard deviations of errors were ge nerally below 2% but increased another 2-3% for large solar zenith angles. Uncertainties of up to 10% may be caused by using an inappropriate profile in total ozone column retrieval. We analyzed the underlying processes causi ng the uncertainties by selecting three ozone and temperature profile pairs characterized by the same unsealed total ozone amount but with different v ertical distributions. Results obtained for cases with ozone redistribution from the stratosphere to the troposphere are consistent with earlier work. However, if the temperature profiles differ significantly in the stratosph ere, an ozone redistribution may lead to a strong decrease in UV doses for high solar zenith angles. It is also shown that differences in ozone maximu m height as well as in ozone concentration in the upper troposphere have a significant influence on surface UV radiation.