Long-term measurements of total NO2 and O3 column contents at stations of the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences: observational methods, long-term trends and interannual variations of the species

The methods are described and the results of long-term measurements of the total NO2 and O3 column content at the Zvenigorod Scientific Station and the Kislovodsk High-Altitude Scientific Station of the A. M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, are discussed. Annual and seasonally dependent estimates of long-term trends and interannual variations of the species under the influence of circulation factors and oscillations in t solar activity are obtained. The differences and common features of the temporal evolution of NO2 and O3 have been revealed. The important role of atmospheric circulation in long-term and interannual changes in the species contents is noted. The obtained estimates of linear trends are compared with the trends of the total NO2 and O3 content in other regions. Changes in the NO2 content under due to the 11-year solar cycle are compared with the results of numerical modeling.