Estimations of Wind Direction and CO 2 Emissions From Power Plants With DaQi-1 Satellite

CO2emissions from power plants are considered the primary source of anthropogenic emissions. Estimating CO2emissions from power plants is essential for tracking global carbon emissions and understanding the global carbon cycle. Satellite remote sensing offers an independent approach to monitoring global CO2emissions. The first space-borne IPDA LiDAR, Aerosol and Carbon Detection LiDAR (ACDL) instrument, onboard the DQ-1, was successfully launched in April 2022. It enables global measurements to be taken during the day and at night. In addition, the ACDL instrument can capture finer plume patterns, attributed to its small footprint of 70 m. However, there are still uncertainties in the CO2emissions quantified from satellite observations. To reduce the impact of the uncertainty of the wind field on the CO2emission estimation, we propose a parameter, plume skewness, to evaluate the wind direction based on the ACDL observations. The effective DAOD enhancements are identified, and wind direction inversion is conducted on 6 power plants using the ACDL observations from June to December 2022. Then, the assessment of power plant emissions is performed with the satellite-derived wind direction, and the CO2emission results are validated against the EPA inventory. Results indicate that the CO2emissions with satellite-derived wind direction consist well with the reported emissions, with a bias of less than 20%. Furthermore, the CO2emission estimates with satellite-derived wind direction are compared with the results with ERA5 wind direction. The mean bias reduced from 11% to 4%, indicating the reliability of satellite-derived wind direction.