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 surface UV radiation, and on total ozone column derived from global irradiance measurements. Measured ozone and temperature profiles from Legionowo, Poland, are used together with typical surface and cloudless atmosphere conditions. The effects of assuming a U.S, standard profile with scaled ozone column instead of actual profiles are analyzed. Variable temperature/ozone vertical distributions and different sets of ozone absorption cross section data may change erythemally weighted radiation by as much as 14% with respect to reference conditions. The mean and standard deviations of errors were generally 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 causing the uncertainties by selecting three ozone and temperature profile pairs characterized by the same unsealed total ozone amount but with different vertical 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 stratosphere, 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 maximum height as well as in ozone concentration in the upper troposphere have a significant influence on surface UV radiation.