Detection of Anthropogenic CO 2 Emission Signatures with TanSat CO 2 and with Copernicus Sentinel-5 Precursor (S5P) NO 2 Measurements: First Results

China’s first carbon dioxide (CO 2 ) measurement satellite mission, TanSat, was launched in December 2016. This paper introduces the first attempt to detect anthropogenic CO 2 emission signatures using CO 2 observations from TanSat and NO 2 measurements 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 XCO 2 measurements have the capability to capture the anthropogenic variations in the plume and have spatial patterns similar to that of the TROPOMI NO 2 observations. The linear fit between TanSat XCO 2 and TROPOMI NO 2 indicates the CO 2 -to-NO 2 ratio of 0.8 × 10 −16 ppm (molec cm −2 ) −1 in Tangshan and 2.3 × 10 −16 ppm (molec cm −2 ) −1 in Tokyo. Our results align with the CO 2 -to-NO x emission ratios obtained from the EDGAR v6 emission inventory.