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| Chemical Composition of Summertime PM2.5 and Its Relationship to Aerosol Optical Properties in Guangzhou, China |
| TAO Jun,CHENG Tian-Tao,ZHANG Ren-Jian |
| 1. South China Institute of Environmental Sciences, Guangzhou 510655, China;2. Department of Environment Science and Engineering, Fudan University, Shanghai 200433, China;3. Key Laboratory of Regional Climate-Environment Research for Temperate East Asia (RCE-TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China |
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Abstract Urban aerosols have a large effect on the deterioration of air quality and the degradation of atmospheric visibility. Characterization of the chemical composition of PM2.5 and in situ measurements of the optical properties of aerosols were conducted in July 2008 at an urban site in Guangzhou, Southern China. The mean PM2.5 concentration for the entire period was 53.7±23.2 μg m-3. The mean PM2.5 concentration (82.7±25.4 μg m-3) on hazy days was roughly two times higher than that on clear days (38.8±8.7 μg m-3). The total water-soluble ion species and the total average carbon accounted for 47.9%±4.3% and 35.2%±4.5%, respectively, of the major components of PM2.5. The increase of secondary and carbonaceous aerosols, in particular ammonium sulfate, played an important role in the formation of haze pollution. The mean absorption and scattering coefficients and the single scattering albedo over the whole period were 53±20 M m-1, 226±111 M m-1, and 0.80±0.04, respectively. PM2.5 had a high linear correlation with the aerosol extinction coefficient, elemental carbon (EC) was correlated with aerosol absorption, and organic carbon (OC) and SO42- were tightly linked to aerosol scattering.
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Received: 27 June 2011
Revised: 12 July 2011
Accepted: 14 July 2011
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