Spatio-temporal evolution of long-range transported mineral desert dust properties over rural and urban sites in Central Europe

An exceptionally strong and very fast (120h) mineral dust inflow from North Africa to Poland was predicted by NMMB/BSC-Dust and NAAPS models on 10-11 June 2019. Simultaneous measurements with two complex lidar systems at the EARLINET-ACTRIS urban site in Warsaw (Central Poland) and the PolWET peatland site in Rzecin (Western Poland) captured the evolution of this dust event. The advected air masses had different source areas in North Africa, they were reaching each station via independent pathways, and thus, were unlikely mixed with each other. The excellent capabilities of the next generation PollyXT lidar and the mobile EMORAL lidar allowed for the derivation of full datasets of aerosol optical properties profiles that enabled comparative study of the advected dust properties evolution. Within a mere 350 km distance between Warsaw and Rzecin, distinctly different dust properties were measured, respectively: dry mineral dust composed mainly of coarse mode dust particles (50 ± 5 % of the total particle backscattering profile) versus the wet mineral dust dominated by fine dust particles (58 ± 4 %). A new parameter fine-to-coarse dust ratio (FCDR) is proposed to describe more intuitively mineral dust composition.