Characteristics and provenance of dustfall during an unusual floating dust event

• Published in: Atmospheric environment (1994) Vol. 44; no. 29; pp. 3477 - 3484
• Main Authors: Lue, Y.L., Liu, L.Y., Hu, X., Wang, L., Guo, L.L., Gao, S.Y., Zhang, X.X., Tang, Y., Qu, Z.Q., Cao, H.W., Jia, Z.J., Xu, H.Y., Yang, Y.Y.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-09-2010; Elsevier
• Subjects: Air pollution; Applied sciences; Atmospheric pollution; Dust; Dust provenance; Earth, ocean, space; Electron probes; Elemental composition; Exact sciences and technology; External geophysics; Floating dust; Meteorology; Minerals; Morphology; Pollution; Sand; Scanning electron microscopy; Size distribution; Asia; Mongolia; China; China, People's Rep., Inner Mongolia; China, People's Rep., Beijing; China, People's Rep., Tianjin; Elemental composition; Size distribution; Morphology; Dust provenance; Floating dust; Elementary analysis; Chemical analysis; X ray; Coarse particle; Transport process; High atmospheric pollution episode; Wind erosion; Fine particle; Silt; Scanning electron microscopy; Atmospheric fallout; Pollutant behavior; Dust fall out; Space remote sensing; Satellite observation; Particle size distribution; Dust; Dust storm; Aerosols; Air pollution
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2010.06.027

This study aims to investigate the characteristics, provenance, and particle-related pollution of an intense dustfall event that occurred in Beijing on 16–17 April 2006. Satellite images reveal that the aeolian dust originated in northeastern Alxa League of Inner Mongolia and passed southeastward across northern Ningxia, middle Inner Mongolia, northern Shaanxi, Shanxi, and Hebei provinces. The dust then moved out of continental China in the vicinity of Beijing and Tianjin. The floating dust led to severe air pollution in Huhhot, Datong, and Beijing. We measured dustfall by collecting dust samples, investigated particle morphology, and calculated the mass medium diameter (MMD) of the dustfall using a scanning electron microscope (SEM). Major elements and mineral content of the dust particles were determined by electron probe and powder X-ray diffractometer, respectively. The relative abundance of dustfall during this event was 12.5–15.0
g
m
−2, making up about 10% of the total annual dustfall in Beijing. Dustfall amounted to 205 thousand tons in Beijing, the largest amount observed in recent years. The dust particles were mostly angular, subangular and subrounded in morphology, and the MMD was nearly 12
μm. Particles <10
μm accounted for 54.7% by number, but fine sand particles (larger than 50
μm) made up 53.7% by volume. Particles with diameters larger than 20
μm made up of the predominant volume of the samples (90.35%). Hence, this dustfall event was characterized by a high content of fine sand and coarse silt particles. The principal elements in the dust particles were C, O, Si, Al, Fe, and Ca, whereas the major minerals were quartz, Na-feldspar, calcite, and clay minerals.