Detection of Anthropogenic CO2Emission Signatures with TanSat CO2and with Copernicus Sentinel-5 Precursor (S5P) NO2Measurements: First Results

China’s first carbon dioxide (CO2) measurement satellite mission, TanSat, was launched in December 2016. This paper introduces the first attempt to detect anthropogenic CO2emission signatures using CO2observations from TanSat and NO2measurements from the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Copernicus Sentinel-5 Precursor (S5P) satellite. We focus our analysis on two selected cases in Tangshan, China and Tokyo, Japan. We found that the TanSat XCO2measurements have the capability to capture the anthropogenic variations in the plume and have spatial patterns similar to that of the TROPOMI NO2observations. The linear fit between TanSat XCO2and TROPOMI NO2indicates the CO2-to-NO2ratio of 0.8 × 10−16ppm (molec cm−2)−1in Tangshan and 2.3 × 10−16ppm (molec cm−2)−1in Tokyo. Our results align with the CO2-to-NOxemission ratios obtained from the EDGAR v6 emission inventory.