Concentrations and fluxes of greenhouse gases over the territory of Western Siberia and Russian Arctic

The IPCC concludes that one of the main causes of global warming is the increase in concentrations of greenhouse and other gases from both anthropogenic and natural sources. Therefore, an accurate assessment of their emissions and sinks, and their redistribution between the atmosphere, oceans and terrestrial biosphere, is crucial for the development of climate policies and the prediction of future changes. However, despite the large number of completed studies on the greenhouse gas budget of the planet, there is still considerable uncertainty in its assessment. This suggests that not all sources and sinks are fully accounted for in the calculations. 

The IAO SB RAS monitors the concentration of greenhouse gases in the surface layer of the air in Western Siberia using 6 high towers located in both the southern and Arctic regions. At 3 complex monitoring stations, 6 main air pollutants identified by the World Health Organization are monitored. Monthly flights are carried out by Tu-134 or Yak-40 optical laboratory aircraft to measure gases, aerosols and soot polluting the atmosphere. During the maintenance of 6 towers, a laboratory vehicle will measure greenhouse gas concentrations in the surface air along the route. In 2024, measurements of greenhouse gas fluxes from the surface of the Ob River began using a chamber method, and during the growing season, flux monitoring continued at the Fonovaya Observatory and Plotnikovo Station. The analysis showed that in the surface air, depending on the region, the trend of carbon dioxide concentration in the surface air was 2.47 - 2.65 ppm / year, the methane content increased at a rate of 5.0 - 12.6 ppm / year. This is above the planetary average.

The annual increase in CO2 in Western Siberia exceeds the global average, but is close to the Mauna Loa Observatory data for March and June 2023-2024: ∆ = 4.4 ppm and ∆ = 3.2 ppm, respectively. In August 2024, the average CO2 concentration was almost 2 ppm lower than in the previous year, which could be the result of the stimulation of the diurnal uptake of carbon dioxide by terrestrial ecosystems in Siberia caused by the record-warm summer of 2024. N2O shows the lowest variability. On average, the concentration increases at a rate of 0.80 ppb / year, this corresponds to the average values for the planet. In the free atmosphere over the southern West Siberian region, the concentration of greenhouse gases also continues to increase at all altitudes. For carbon dioxide the average is 2.21 ppm/year, and the rate of increase of its concentration is maximum at the height of 0.5 km - 2.24 ppm/year, and minimum at the height of 3 km - 2.19 ppm/year. The increased rate of increase of the CO2 concentration in the atmospheric boundary layer in summer continues, where it reaches 2.50 ppm/year. An increase in the methane content is also observed throughout the troposphere, with an average of 9.1 ppb/year. The maximum growth rate was recorded in the boundary layer - 9.7 ppb/year, the minimum - 9.0 ppb/year is recorded at an altitude of 4-5.5 km.