2023 , Volume 28, № 2, p.103-114

The purpose of this work is to establish the behaviour of the total carbon dioxide content in an atmosphere of the steppe zones of Altai krai and Novosibirsk region in 2014–2021, as well as to obtain quantitative estimates of the gross primary production using the product “Solar induced chlorophyll fluorescence” (SIF) of the orbital carbon observatories OCO-2 and OCO-3.

Methods. To achieve this goal, we processed the CO ₂ and SIF product content data at the orbital carbon observatories OCO-2 and OCO-3. The analysis of OCO-2 data was carried out for the period 2014–2021, the results of OCO-3 were added to processing in 2019. To describe the seasonal cycle of CO₂ in the atmosphere, we used an empirical model proposed for the interpretation of the GOSAT satellite data and verified by the results of measurements of the global network TCCON.

Results. It has been established that for the period under study, the growth rate of CO₂ in the atmosphere of the steppe regions of Altai krai is ∼2.36±0.6 ppm/year, the amplitude of seasonal fluctuations is ∼5.0 ppm. For the steppe zones of Novosibirsk region, the growth rate of CO₂ is ∼2.52±0.09 ppm/year, the amplitude of seasonal fluctuations is ∼4.8 ppm. It is shown that the average gross primary production due to the processing of atmospheric CO₂ by terrestrial vegetation in the steppe ones of Altai krai and Novosibirsk region reaches a maximum in the summer months and is equal to ∼10–12 gC/( m² day).

Conclusions. Using the CO₂ and SIF product content data at the OCO-2 and OCO-3 orbital carbon observatories, we carried out the study of the behavior of the total carbon dioxide content in the atmosphere of the steppe zones of Altai krai and Novosibirsk region. The quantitative estimates of gross primary production in these regions have been obtained for the first time.