Surface and total ozone investigations in the region of Sofia, Bulgaria

Abstract

Atmospheric ozone behaviour over Sofia has been investigated with remote-sensing and in situ techniques. Surface ozone and boundary layer observations performed in recent years at three city sites have been analysed. It was found that, in the autumn period, at close meteorological conditions, diurnal ozone variations show stable behaviour from year to year during the analysed period. It may be assumed that the boundary layer and ozone precursor concentrations, which are involved in photochemical ozone formation, keep up their state from year to year at the mentioned conditions. These findings may be interesting when surface ozone trends and climate change influence on ozone are investigated. The analysis of the long-term total ozone content (TOC) variations did not find a total ozone trend in the 1997–2008 period.