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

• Main Authors: Fomba Khanneh Wadinga, Müller Konrad, Hofer Julian, Makhmudov Abduvosit N., Althausen Dietrich, Nazarov Bahron I., Abdullaev Sabur F., Herrmann Hartmut
• Format: Article
• Language: English
• Published: EDP Sciences 2019-01-01
• Series: E3S Web of Conferences
• Online Access: https://www.e3s-conferences.org/articles/e3sconf/pdf/2019/25/e3sconf_caduc2019_03007.pdf

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.