[Sensitivity Study of Aerosol Properties from Observation of Atmospheric Ring Effect]

Ring effect is defined as the phenomenon that the depth of solar Fraunhofer lines in scattered light is less than those observed in direct sunlight. The aerosol could change the light path and the scattering properties in the atmospheric, and influence Raman Scattering Possibility of the photons, and finally affect the filling-up effect. Aerosol parameters (aerosol optical depth, boundary layer height, single scattering albedo, asymmetric factor) could be obtained by observation of the Ring effect in different aerosol condition. The Ring effect is measured by ground-based MAX-DOAS instrument under clear days and the measurement results is compared with McAritim results. The comparison has a good agreement. Radiation transfer model McArtim is used to study the sensitivity of the Ring effect to the aerosol parameters. The study shows that in most conditions, aerosol optical depth (AOD) and boundary layer (bh) height has a great influence to RSP, and in 90 degree elevation angle, RSP has a decrease of 24.6% when AOD varies from 0.1 to 1, and a decrease of 4.4% when bh varies from 1km to 3 km. The study shows RSP is more sensitive to AOD and boundary layer height, which may provide a new method for aerosol profile.