Measurement report: The Urmia playa as a source of airborne dust and ice-nucleating particles – Part 1: Correlation between soils and airborne samples

Abstract. The emergence of desiccated lake bed sediments and their exposure to wind erosion as a consequence climate change drought in arid semiarid regions the world poses growing hazard. Airborne dust originating from such soils can create health environmental issues due high salt content presence toxic elements. aim present study is twofold, namely investigate newly emerged playa surfaces western Lake Urmia (LU) Iran contribution aerosol region by means physicochemical, mineralogical, elemental analyses ice nucleation (IN) activity both surface-collected soil airborne samples. created desiccation LU on shores were mapped sampled at 130 locations. Soil samples subjected physicochemical analyses, erodible fraction was determined. Based these four highly northwest south selected sites for collection impaction uppermost surface. Their particle properties (size distribution, mineralogical composition) compared with IN determined emulsion freezing experiments differential scanning calorimeter (DSC) two suspension concentrations 2 wt % 5 %. differed significantly between different surfaces, which affects susceptibility erosion. Sand sheets sandy crusts most sand low organic matter clay content, favouring small aggregates. Mineralogical document prevalence quartz, carbonates, minerals, kaolinite, palygorskite, chlorite all predominant elements are Ca, Fe, Al, Si, Na (and some cases Ba, Sr, Zn). correlation based composition, enrichment factors, confirm that major contributors region. onset temperatures ranging 245 250 K demonstrates potential blown affect cloud precipitation. Freezing heterogeneously frozen droplets emulsions reveal variations depending composition but also influenced matter, salinity, pH. Specifically, correlates positively minerals negatively pH, (surprisingly) K-feldspar quartz content. erodibility production together play an important role thus needs careful monitoring specific attention.