2008年夏季广州大气消光系数与细粒子的关系

为了解夏季广州大气中细粒子消光特性,利用浊度仪、黑碳仪和自动气象站获得散射系数μsp、吸收系数μap以及气象要素等观测数据,并利用采样器采集大气悬浮颗粒物PM2.5和PM1.0样品获取其质量浓度。结果表明,散射系数μsp、吸收系数μap和大气消光系数(μext=μsp+μap)的平均值分别为(226±111)、(53±20)、(280±125)Mm-1;大气悬浮颗粒PM2.5和PM1.0的质量浓度分别为(53.7±23.2)、(46.1±21.3)μg/m3;消光系数μext与PM2.5和PM1.0的相关性系数分别达到0.96和0.93;PM2.5和PM1.0的平均质量浓度消光效率分别为到5.2、5.5 m2/g,表明大气中小粒径的粒子对消光系数的影响更为明显。

Relationship Between Ambient Light Extinction Coefficient and Fine Particles in Guangzhou, 2008 Summer

To obtain the extinction properties of fine particles in aerosol,light scattering μsp,absorption coefficient μap and selected meteorological factors were measured with a Nephelometer,an Aethalometer and an automatic weather station,respectively,in July 2008.In-situ PM2.5 and PM1.0 mass concentrations were collected by two samplers.The results show that the average light scattering μsp、absorption coefficient μap and light extinction eoefficient(μext=μsp+μap) are(226±111),(53±20),(280±125) Mm-1,respectively.The mass concentrations of PM2.5 and PM1.0 are(53.7±23.2),(46.1±21.3) μg/m3.The correlation coefficients of μext to PM2.5 and PM1.0 are 0.96 and 0.93.The mass extinction efficients of PM2.5 and PM1.0 are 5.2,5.5 m2/g.It suggests that the smaller size particles have higher extinction efficiency than the larger ones.