HYSPLIT Inverse Modeling Using Flight Observations to Estimate SO2, CO2, and NOx Point Source Emissions

A HYSPLIT inverse modeling system has been developed to estimate source terms by assimilating various observations. The system has been applied using measurements from surface monitoring stations as well as polar orbiting and geostationary satellites. In this study, the HYSPLIT inverse modeling system is tested with flight observations collected in 2019 by University of Maryland Cessna 402B research aircraft to estimate SO₂, CO₂, and NO_x point source emissions from three power plants in North Carolina. Sensitivity studies are first performed on observation pre-processing and background concentration options. These source estimation results from the inverse modeling will be compared with CEM (continuous emissions monitoring) data as well as those obtained through a simple mass balance approach. In addition, the uncertainties of the results from the inverse modeling method and the mass balance approach will be discussed.