Quantifying and Attributing CO Emissions Using TROPOMI-based CO retrievals and Explicit Observational Uncertainty over Rapidly Developing Central Asia

Daily, gridded emissions of CO from 2019 to 2023 were calculated using a new approach based on daily TROPOMI CO and HCHO column data within the MFIEF (model free inversion estimation framework). The robustness, significance, and uncertainty of emissions were analyzed over rapidly changing areas in Central Asia which currently do not have access to other long-term observational datasets. The results revealed distinct temporal and spatial patterns of CO emissions, including a peak in 2019 and a reducing trend until 2021 throughout. Anthropogenically influenced areas were demonstrated to continue their downward trend in 2022 while natural areas increased in 2022, and all areas increased in 2023. Emissions were found to be highest during the months with the least UV radiation and coldest temperatures. The inclusion of explicit observational uncertainty had a substantial impact on the calculated emissions, with approximately 55% of data deemed unreliable.