Long-term trends of variations in total ozone content according to data of ground-based (Tomsk: 56.48°N, 85.05°E) and satellite measurements

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