The paper compares the results of ground-based measurements of total ozone (TO) content in Tomsk (56.48°N, 85.05°E) with the use of М-124 ozonometer against satellite data, obtained with the help of TOMS instruments. Different algorithms of TO retrieval from satellite data are considered. TO trends over Tomsk and at some Northern Hemisphere sites for period 1979-2010 are analyzed. Based on satellite and ground-based measurements for Tomsk, there are negative linear trend of (-2.3±0.1) DU per year for the period 1979-1995 and positive trend of (1.08±0.1) DU per year for the period 1996-2010.
total ozone content, time series, trend