Spatial and temporal variations of dust concentrations in the Gobi Desert of Mongolia

Abstract

Dust mass concentrations of PM 10 and PM 2.5 from four monitoring stations in the Gobi Desert region of Mongolia were analyzed for a 16-month period in 2009–2010. Annual averaged PM 10 concentration ranged from 9 μg m − 3 to 49 μg m − 3 at these stations during 2009. Concentrations were high in winter owing to air pollution and in spring owing to dust storms; the monthly mean concentrations of PM 10 (PM 2.5) at the three stations except for Sainshand reached yearly maxima in December and January, ranging from 60 (38) μg m − 3 to 120 (94) μg m − 3 . Diurnal variations of PM 10 and PM 2.5 concentrations at two sites, Dalanzadgad and Zamyn-Uud, included two maxima in the morning and evening and two minima in the afternoon and early morning. However, at Erdene PM 10 maxima occurred in the afternoon and evening. Both PM 10 and PM 2.5 concentrations were enhanced from March to May by dust storms. Dust storms raised huge amounts of fine dust particles in the Gobi of Mongolia. Maximum daily mean PM 10 (PM 2.5) concentrations reached 821 (500) μg m − 3 at Dalanzadgad, 308 (129) μg m − 3 at Zamyn-Uud, and 1328 μg m − 3 at Erdene. Hourly maximum PM 10 (PM 2.5) concentrations were as high as 6626 (2899) μg m − 3 at Dalanzadgad during a dust storm.