E3S Web of Conferences (Jan 2019)

Variations of the aerosol chemical composition during Asian dust storm at Dushanbe, Tajikistan

  • Fomba Khanneh Wadinga,
  • Müller Konrad,
  • Hofer Julian,
  • Makhmudov Abduvosit N.,
  • Althausen Dietrich,
  • Nazarov Bahron I.,
  • Abdullaev Sabur F.,
  • Herrmann Hartmut

DOI
https://doi.org/10.1051/e3sconf/20199903007
Journal volume & issue
Vol. 99
p. 03007

Abstract

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Aerosol chemical composition was characterized during the Central Asian Dust Experiment (CADEX) at Dushanbe (Tajikistan). Aerosol samples were collected during a period of 2 months from March to May 2015 using a high volume DIGITEL DHA-80 sampler on quartz fiber filters. The filters were analyzed for their ionic, trace metals as well as organic and elemental carbon (OC/EC) content. The aerosol mass showed strong variation with mass concentration ranging from 18 μg/m3 to 110 μg/m3. The mineral dust concentrations varied between 0.9 μg/m3 and 88 μg/m3. Days of high aerosol mass loadings were dominated by mineral dust, which made up to about 80% of the aerosol mass while organic matter and inorganic ions made up about 70% of the aerosol mass during days of low aerosol mass loadings. The mineral dust composition showed different trace metal signatures in comparison to Saharan dust with higher Ca content and Ca/Fe ratios twice as high as that observed in Saharan dust. Strong influence of anthropogenic activities was observed in the trace metal concentrations with Zn and Pb concentrations ranging from 7 to 197 ng/m3 and 2 to 20 ng/m3, respectively. Mineral dust and anthropogenic activities relating to traffic, combustion as well as metallurgical industrial emissions are identified as the sources of the aerosol during this period.