ROLE OF URBAN AND SUBURBAN AEROSOLS ON SOLAR UV-RADIATION OVER ATHENS, GREECE

The scope of this paper is to provide an experimental and modelling co ntribution on the role of suspended lower tropospheric particles to th e UV spectral irradiance reaching the ground in urban environments. Th e UV spectral irradiance was measured with a UV spectrophotometer, whi le the aerosol data were obtained simultaneously by a lidar system ope rating in the 300 nm spectral region. Both UV and lidar instruments we re operated inside the Athens basin during various air pollution and m eteorological conditions, in the Frame of the European MEDCAPHOT-TRACE Campaign in summer 1994. Aerosol vertical profiles were also obtained by a second lidar system operated outside the Athens basin (in a sub- urban area) during the same time period and were intercompared to the urban profiles. Using the lidar data as input to a radiative transfer model (MODTRAN), we provide comparisons of measured and modelled spect ral UV irradiances under distinct environmental conditions. (C) 1998 E lsevier Science Ltd. All rights reserved.