Aerosol Particles from Dried Salt-Lakes and Saline Soils Carried on Dust Storms over Beijing

  • Author(s): Xingying Zhang, Guoshun Zhuang, Hui Yuan, Kenneth A. Rahn, Zifa Wang, and Zisheng An
  • DOI: 10.3319/TAO.2008.07.11.03(A)
  • Keywords: Dust storm, Individual particle analysis, Correlation of S/Cl, Salt lake and saline soil
  • Citation: Zhang, X., G. Zhuang, H. Yuan, K. A. Rahn, Z. Wang, and Z. An, 2009: Aerosol particles from dried salt-lakes and saline soils carried on dust storms over Beijing. Terr. Atmos. Ocean. Sci., 20, 619-628, doi: 10.3319/TAO.2008.07.11.03(A)

Characteristics of individual particles from a super dust storm (DS) on 20 March 2002, and those of non dust storm aero sols for Beijing (NDS) and Duolun (DL) (a desert area) are determined using a variety of methods. In China, typically the source of aero sols in dust storms is thought to be deserts with alumino silicates being the main constituent particles; how ever, this does not reflect a complete analysis with our evidence indicating potential alternate dust sources along the storm¡¦s trans port path. Individual particle anal y sis of aero sols collected from a super dust storm on 20 March 2002 in Beijing shows that among all the 14 elements measured, only S and Cl have re mark able positive correlation. 82.5% of all particles measured contained both S and Cl, and the relative mass per cent age of S and Cl in these particles is much higher than the average of all particles. 62.0% of all particles contained S, Cl, and Na, in which the concentration of Na is 1.4 times higher than average. PMF (Positive Matrix Factorization) anal y sis indicates that NaCl and Na2SO4 are major components of these particles with S and Cl showing significant positive correlation. More over, SO4 2- and Cl- also show significant positive correlation in bulk aero sol analysis. XPS (X-ray Pho to electron Spectros copy) analysis of the surface of aero sols demonstrates that concentrations of Na and S on particles from the dust storm are higher than those from non-dust storm particles in Beijing and also for particles from. It is very likely that particles enriched with S, Cl, and Na is from the surface soils of dried salt-lakes and saline soils enriched with chloride and sulfate. This evidence demonstrates that be sides deserts, surface soils from dry salt-lakes and saline soils of arid and semi-arid areas are also sources of particulates in dust storms over Beijing.

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