Dust storms in China: a case study of dust storm variation and dust characteristics

Abstract

The paper discusses the nature of dust storms, which have inherent environmental implications. The physical, chemical and mineralogical properties of dust sediments collected in Kashi, Taklimakan desert, Kunlun mountains, Donghuang, Lanzhou, Ningxia, Xi'an, Inner Mongolia and Beijing from 1990 to 1994 were studied. The texture of most aeolian deposits ranges from silty clay to clay loam with median particle diameters (Mds) generally between 5 and 63 µm; similar to the loess of central China and the silt/fine sand in western and northern China. The dust sediments were characterized by a predominance of SiO2 and Al2O3 and a high amount of K2O with molar ratios for SiO2/Al2O3 and K2O/SiO2 from 5.17 to 8.43 and 0.009 to 0.0368 respectively. The triple peak spectrum is the main form of mass concentration in a clear sky. In a dust storm it shows as a single peak, with quartz, feldspar, chlorite, illite, calcite and dolomite being the dominant minerals. The physical, chemical and mineralogical properties of the present atmospheric dust are similar to those of wind-blown soils in western and central China. The results suggest that aeolian deposits and the fine-grained fractions of dust sediments collected in northern China are mainly soils transported from the arid and semi-arid regions of China and Mongolia by the prevailing winds.