Properties of Saharan Dust Versus Local Urban Dust—A Case Study

Abstract

On June 29–30, 2019, the Barcelona Dust Forecast Center with Non‐hydrostatic Multiscale Model (NMMB/BSC‐Dust) and the Navy Aerosol Analysis and Prediction System forecasted huge amounts of mineral dust over Poland. The Hybrid Single Particle Lagrangian Integrated Trajectory model confirmed uniquely fast (120 hr) long‐range air‐mass transport form North Africa to Poland. This remarkable dust event was observed using lidar at the Aerosol, Clouds and Trace Gases Research InfraStructure site in Warsaw, Central Poland; the only site equipped with Raman‐Mie polarization water vapor lidar in East‐Central Europe. The excellent capabilities of PollyXT lidar allowed to obtain an impressive number of 31 full sets of aerosol optical properties profiles, which enabled study of dust properties evolution on a rare hourly scale. The analyses were completed with the separation of fine and coarse mode dust particles form non‐dust particles using the POlarization‐LIdar PHOtometer Networking algorithm. Huge amount of an exceptionally pure mineral dust from Sahara measured in the free troposphere was characterized by a gradually decreasing coarse dust fraction (76%–21%) with a peak of fine dust fraction (67%) and particle linear depolarization ratio (26%) in the middle of the event. Within the boundary layer, a local urban dust mixed with pollution was observed with fine mode dust particles dominating (44%) and lower particle linear depolarization ratio (7.4%). The influx of pure mineral dust has been unique to this geographical region and will therefore be a reference point for future research and comparative studies.

First Ever Observations of Mineral Dust in Wintertime over Warsaw, Poland

“…Obtained values suggest the presence of coarse and fine aerosol particles (all values of AE observed), with the δ ranging from 7-25% and 13-30% for 355 and 532 nm, respectively. Such high δ values indicate the presence of a strongly depolarizing aerosol, but the obtained values are still slightly lower than those reported previously for the clean mineral dust observations over Warsaw [14]. The obtained values suggest a possible presence of other aerosol types, which is supported by the high LR values, especially for 355 nm.…”

“…Large amounts of desert dust are long-range transported in the free troposphere far from the source area and observed with terrestrial and satellite remote sensing instruments [5]. In the case of measurements performed in Poland, many episodes of the inflow of mineral dust were observed [11][12][13][14]. Usually, the mineral dust inflow comes along with extreme weather conditions, such as prolonged heat waves, which negatively affect human life and health [15].…”

Statistical bias correction for CESM-simulated PM2.5

“…Unexpectedly, results for Poland also suggest a relatively large contribution of dust aerosols (32%) to overall PM 2.5 , which is comparable to that of POM (37%). There are significant local sources of dust in Poland especially in heavily industrialized Silesia and southern Poland, and advected dust from the Ukrainian steppe and Saharan sources (Milinevsky et al 2020) that varies greatly on seasonal scales and from year to year (Milinevsky et al 2020, Szczepanik et al 2021. This combination of sources in Poland differentiates it from countries in western and southern Europe (Di Iorio et al 2009, Israelevich et al 2012, where dust is relatively less important, e.g., Germany and Italy in figure 4.…”

A Decade of Poland-AOD Aerosol Research Network Observations

“…The methodology for the retrieval of the AOD within the boundary layer (AOD BL ) and the entire troposphere using an iterative extrapolation (lower range) and interpolation (upper range) from the lidar data are detailed in [16,17]. The aerosol typing schemes applied for the lidar data for the case of the molecular aerosol and cloud scattering separation are described in [38] and for fine/coarse mode dust and anthropogenic pollution in [40].…”

“…Both campaigns focused on a characterization of the atmospheric composition obtained from different combinations of remote sensing and in situ instrumentation, such as the ESA Mobile Raman Lidar EMORAL, the PollyXT lidar, the BASTA 95GHz Doppler cloud radar (provided by LATMOS, France), the HALO Doppler lidar (provided by the University of Granada, Spain), the HATPRO microwave radiometer (provide by INOE, Romania), the CIMEL photometer, the static chamber sites for CO 2 , CH 4 , and water vapour flux measurements. The synergy of data obtained from remote sensing instruments was used to discriminate molecular, aerosol, and cloud particles [30], to assess the contribution of free troposphere aerosols to total aerosol loading within the troposphere [40,58] and stratosphere [59], including ongoing work on estimation of the aerosol vertical fluxes within the boundary layer.…”