Tropospheric vertical profiling of the aerosol backscatter coefficient and the particle linear depolarization ratio for different aerosol mixtures during the PANACEA campaign in July 2019 at Volos, Greece

Abstract

The PANhellenic infrastructure for Atmospheric Composition and climate change (PANACEA) campaign took place in July 2019, to assess the presence of aerosols both in situ and at different heights, in selected cities of Greece suffering from high air pollution levels. One of these sites was the city of Volos (39.21° N., 22.57° E). Vertical profiles of the aerosol backscatter coefficient (baer) and the particle linear depolarization ratio (δp) of maritime polluted, urban, smoke and dust mixtures were measured during using the mobile depolarization Aerosol lIdAr System (AIAS). 42 aerosol layers were characterized, out of which 40% were of urban origin, 26% of smoke origin, 21% maritime polluted aerosol layers and 12% dust mixtures. The maritime polluted and urban aerosols showed a mean δp value at 532 nm of 4 ± 1%, within a range of 2–6% and 2–5%, respectively. The smoke aerosols showed a mean δp value of 6 ± 1%, within a range of 3–9%, while the dust mixtures showed a mean δp of 20 ± 4%, ranging from 13 to 29%. Finally, the majority of these layers were observed above 250 up to 2000 m height asl., although the dust mixtures reached 3000 m height asl.