Size distribution and element composition of dust aerosol in Chinese Otindag Sandland

Dust aerosol is one important component of atmos-pheric aerosols, and plays important roles in the Earth’s climate system and the biogeochemical cycle. Large amounts of dust aerosols produced from windblown soils and deserts are emitted annually into the atmosphere and transported over long distance to downwind land and ocean areas1]. The deserts and desertification soils in northern China are important sources of East Asia dust aerosols. It is estimated that 800 Mt of dust aerosols emit-t…

Size distribution and element composition of dust aerosol in Chinese Otindag Sandland

Part physical and chemical characteristics of dust aerosol were determined for samples collected from Otindag Sandland of China in spring, 2001. Number concentration, mass concentration, chemical element concentration and size distribution of aerosol particles with 0.5 μm < D_p < 100.0 μm were examined. The average number and mass concentrations of aerosols were 274.8 cm⁻³ and 0.54 mg/m for the field period respectively, and 31.4 cm⁻³ and 0.07 mg/m³ for the non-dusty days. PM10 played a dominant role in the aerosol mass concentrations. The particles with D_p < 8.0 μm accounted for about 93.7% of total aerosol number loading in dusty days. The particle size distributions of aerosols were characterized by bi-modal logarithm normal function in heavy and moderate dusty days, and mono-modal in windblown and non-dusty days. Crustal elements such as Al, Fe, etc. in aerosols almost originated from soils. Pollutant elements of S, Pb, etc. associated with aerosols were affected by remote anthropogenic pollutant sources in upwind regions. Mo, V and Co in aerosols were possibly from other dust sources other than local soils. The aerosols over Otindag Sandland consisted of particles from local soils, upwind pollutant sources and other dust sources.