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Abstract
In this paper we present a statistical analysis of the Sahara dust events observed over Athens, Greece, in a three-year period from January 1, 2004 up to December 31, 2006. The observations of the vertical aerosol profile were performed by the multi-wavelength (355-532-1064-387-607 nm) Raman lidar system of the National Technical University of Athens (NTUA) operated in the city of Athens (37o98' N, 23o77' E), Greece, in the frame of the European Aerosol Research Lidar Network (EARLINET-ASOS) project. The number of dust events was greatest in late spring, summer, and early autumn periods. Multiple aerosol dust layers of variable thickness (680-4800 m) were observed. The center of mass of these layers was located in altitudes between 1600 and 5800 m. However, the mean thickness of the dust layer typically stayed around 2700 m and the corresponding mean center of mass was of the order of 2900 m. The top of the dust layer ranged from 2000 to 8000 m, with a mean value of the order of 4700 m. Mean aerosol optical depths (AOD) and extinction-to-backscatter ratios (lidar ratios, LR) of the desert aerosols ranged from 0.35 to 0.65 at 550 nm, and from 40 to 100 sr at 355 nm, respectively, within the lofted dust plumes.