Study of the effect of different type of aerosols on UV-B radiation from measurements during EARLINET

[摘要] Routine lidar measurements of the vertical distribution of the aerosol extinction coefficient and theextinction-to-backscatter ratio have been performed at Thessaloniki, Greece using a Raman lidarsystem in the frame of the EARLINET project since 2000. Co-located spectral and broadband solarUV-B irradiance measurements, as well as total ozone observations, were available wheneverlidar measurements were obtained. From the available measurements several cases could beidentified that allowed the study of the effect of different types of aerosol on the levels of the UV-Bsolar irradiance at the Earth's surface. The TUV radiative transfer model has been used to simulatethe irradiance measurements, using total ozone and the lidar aerosol data as input. From thecomparison of the model results with the measured spectra the effective single scattering albedowas determined using an iterative procedure, which has been verified against results from the 1998Lindenberg Aerosol Characterization Experiment. It is shown that for the same aerosol opticaldepth and for the same total ozone values the UV-B irradiances at the Earth's surface can showdifferences up to 10%, which can be attributed to differences in the aerosol type. It is shown that thecombined use of the estimated single scattering albedo and of the measuredextinction-to-backscatter ratio leads to a better characterization of the aerosol type probed.

[学科分类] 大气科学