[A-CG37] 衛星による地球環境観測

[ACG37-03] Local anthropogenic CO₂, CH₄ and CO enhancements observed by the GOSAT-2 satellite

*Shamil Maksyutov¹、Rajesh Janardanan¹、Yukio Yoshida¹、Tsuneo Matsunaga¹ (1.National Institute for Environmental Studies)

キーワード：greenhouse gases, anthropogenic emission inventory, GOSAT-2

We use observational data by the Greenhouse gases Observing SATellite-2 (GOSAT-2) for detecting the local anthropogenic greenhouse gas (GHG) emission signatures in the total column-averaged concentrations of CO₂, CH₄, and CO around the globe. We use the column-averaged CO₂, CH₄, and CO concentration data retrieved with NIES Level 2 v.02.00 full physics algorithm. To relate the observations to the anthropogenic methane and carbon dioxide emission inventory in various regions, we extract localized emission anomalies from column-averaged GHG observations by the GOSAT-2 satellite using high-resolution atmospheric transport model simulations made with FLEXPART model, that match the size of the satellite observation footprint and the emission inventory of 0.1 degree. CO₂, CH₄ enhancement due to anthropogenic emissions are estimated as the difference between polluted observations from surrounding clean background observations after categorizing the observations with the Lagrangian model simulations. To reduce the impact of the observation error we apply binning of the observations over large regions according to model-simulated enhancement levels with a bin size of 0.1 ppm CO₂ and 0.02 ppm CH₄. We found that the local enhancements observed by GOSAT-2 scale linearly with inventory-based simulations of XCH₄ and XCO₂ for the globe, confirming suitability of GOSAT-2 data as a continuity data source for GOSAT data useful for quantification of regional methane and carbon dioxide emissions. Additionally, we confirmed that CO concentration enhancements correlate strongly with CO₂ enhancements giving data users a much-needed tool to observe the CO₂/CO emission ratio from space.