Sensitivity Study of Aerosol Parameters from Observations of O4 Absorption by MAX-DOAS

Sensitivity of retrieving aerosol optical parameters from O-4 absorption measured by ground-based differential optical absorption spectroscopy was studied. The influence of different wavelength and aerosol optical parameters (aerosol optical density, boundary layer height, single scattering albedo and asymmetric factor) on the absorption of O-4 was analyzed by the atmospheric radiation transfer model (McArtim). The results show that the air mass factor is not sensitive to the wavelength change, and the aerosol optical density and boundary layer height have an important influence on O-4 absorption (air mass factor). When the aerosol optical density increases from 0.1 to 1, the air mass factor measured at 3 degrees decreases by 28%. And when the boundary layer height increases from 0.1 km to 1 km, the air mass factor measured at 3 degrees increases by 9.2%. The O-4 absorption has a good sensitivity to single scattering albedo and asymmetric factor under the flat-latitude observation mode, which provides a new method to retrieve aerosol optical parameters based on the observation of O-4 absorption by ground-based MAX-DOAS.