Spatial and temporal variability of CO2 and CH4 concentrations in the surface atmospheric layer over West Siberia

The diurnal and annual variation of the CO 2 and CH 4 concentrations and their spatial distribution over a network of sites developed over the territory of West Siberia are investigated. The CO 2 concentration gradient between the northern and southern regions of the territory is retained during the entire year. The diurnal behavior of the methane concentration remains neutral for much of the year, so that it is only at the end of the springtime and at the beginning of the summer that it exhibits a significant amplitude. The annual variation of CO 2 has a maximum in the month of December, the concentration starts to decrease in March, and reaches a minimum in July in August. In the central region of the territory, the annual variation of methane has two maxima (in July and in December and January); the greatest interyear methane concentration variability is recorded during the periods of the basic and secondary maxima.