HR: 1340h
AN: A53C-1361    [Abstracts]
TI: The formation mechanism of heavy haze over China
AU: * Li, J
EM: juanli0817@163.com
AF: Center for Atmospheric Chemistry Study, Department of Environmental Science and Engineering Fudan University, 220 Handan Rd., Shanghai, SH 200433, China
AU: Zhuang, G
EM: gzhuang@FUDAN.EDU.CN
AF: Center for Atmospheric Chemistry Study, Department of Environmental Science and Engineering Fudan University, 220 Handan Rd., Shanghai, SH 200433, China
AB: Most cities in China have been suffering from very heavy haze, a new weather pattern, which formed for more than one third of the whole year in the past several years. High concentration of fine aerosol, much frequent occurrence plus rapid formation were the three main characteristics of the heavy haze. As a typical example, the air pollution in an inland city, Urumqi, located in the center of Asia, was systematically monitoring and investigated for the past 6 years. 19 elements and 16 ions were measured in PM2.5 and TSP aerosols collected over urban Urumqi, as well as those surface soil samples collected from inside the city, the surrounding areas, and those upstream areas of Asia dust. With comparison of the pollution elements abundance in aerosol/soil and using Ca/Al as a tracer, it was identified that the mixing of the local anthropogenic aerosol with the transported soil dust from outside the city was the main sources of the high concentration of sulfate, which was the one of the main factors causing the heavy air pollution in the aerosols over the urban area. The industrial emitted sulfur dioxide was converted to sulfate in the aerosol and the soil dust containing high concentration of sulfate from the agriculture field located in the south of Jungger Basin and Salt Lake areas was transported to the air over the city. The total water soluble ions (TWSI) and the total ammonium salts were as high as 57.8% and 51.0% in PM2.5. The extremely high concentration of TWSI, especially the high concentration of ammonium salts with very high hygroscopicity, plus the low wind speed could be the main factors, to form the heavy haze over China.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0335 Ion chemistry of the atmosphere (2419, 2427)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting