广州冬季大气消光系数的贡献因子研究

Contribution Factors of Ambient Light Extinction Coefficient in the Winter of Guangzhou

摘要: 2008年1月1～31日和2月6～24日在广州城区每天采集一个PM25样品，对样品进行有机碳、元素碳及水溶性离子分析，利用美国IMPROVE 能见度方程计算得到广州冬季大气消光系数。结果发现：冬季PM2.5日均值质量浓度为89.0±53.4 μg·m-3，OC（Organics Carban）质量浓度为16.9±11.9 μg·m-3，EC（Element Carbon）质量浓度为5.9±34 μg·m-3，水溶性离子总浓度为43.9±23.5 μg·m-3。冬季大气消光系数均值为342±185 Mm-1。广州冬季大气消光系数主要贡献者为(NH4)2SO4、NH4NO3、POM(Particular organic matter)、EC和NO2，对消光系数的贡献率分别为36.3%、14.5%、26.6%、17.4%和5.2%。

Abstract: Aerosol samples of PM2.5 were collected from 1 January to 31 January and 6 February to 24 February 2008 in Guangzhou. The concentrations of organic carbon, element carbon, watersolubility ions of all particle samples were obtained by chemical analyses. Ambient light extinction coefficients were calculated by IMPROVE visibility formula. The results indicated that the average mass concentration of PM2.5, OC, EC, watersolubility ions was 890±53.4, 16.9±11.9, 5.9±3.4, and 43.9±23.5 μg·m-3, respectively. The averaged value of extinction coefficient was 342±185 Mm-1 in winter. The major contributors to ambient light extinction coefficients included (NH4)2SO4(36.3%), NH4NO3(14.5%), POM(26.6%), EC(17.4%), and NO2(5.2%), respectively.