Here, we present the results of analysis of interannual variability and frequency of occurrence of atmospheric pressure systems and air masses of different types observed in the Tomsk region over the period from 1993 to 2016. The following types of APS were analyzed: cyclones, anticyclones, troughs, ridges, low-gradient baric fields, and contrast zones (areas of high-gradient baric filed between Zn and Azn). It is shown that the difference in the frequency of cyclones and anticyclones has significantly decreased over the past decade in the Tomsk region. In 2015 - 2016, their repeatability was almost the same. There is a tendency to decrease in the frequency of Arctic air mass occurrence and increase in subtropical air masses. During the past decade, tropical air masses have become to be observed more often in our region, especially in the spring.
The content of gaseous species of atmosphere (СО, СO<sub>2</sub>, NO<sub>2</sub>, O<sub>3</sub>, СН<sub>4</sub>) during the period of smoke haze caused by forest fires in the summer 2012 over Siberia is analyzed on the base of satellite and ground-based (Tomsk) measurements. The temporal evolution of the spatial distributions of carbon monoxide and aerosol optical thickness of the atmosphere over Tomsk region is discussed.