The temporal and spatial distributions of the near-surface CO2 concentrations in Central Asia and analysis of their controlling factors

Abstract

As the main anthropogenic greenhouse gas that contributes most to global warming, CO2 plays an important role in climate changes in Central Asia. Due to the lack of studies of near-surface CO2 in this region, we first confirmed the applicability of the near-surface Greenhouse Gases Observing Satellite (GOSAT) CO2 data in Central Asia using atmospheric CO2 concentration data from nine ground-based station observations. We then analyzed the temporal and spatial distributions of the near-surface CO2 concentrations in Central Asia and their controlling factors using statistical analysis methods. The results show that the near-surface CO2 concentrations are high in the western part of this region and low in the east. From June 2009 to May 2013, the near-surface CO2 concentrations increased gradually, with the highest value being in spring and the lowest in autumn. The temporal distribution of CO2 concentrations is mainly affected by photosynthesis, respiration, and heating. The combined effect of terrestrial ecosystems and CO2 diffusion by wind is responsible for the higher near-surface CO2 concentration in the northern, western, and southwestern areas of the five Central Asian countries compared to the central, eastern, and southern areas, and energy consumption and wind are the major factors that affect the heterogeneity of the spatial distribution of the CO2 concentrations in Xinjiang.