典型地区大气气溶胶谱分布和复折射率特征研究

Research on the characteristics of aerosol size distribution and complex refractive index in typical areas of China

为了研究典型地区大气气溶胶的谱分布和复折射率的特性,综合运用了黑碳仪、能见度仪、积分浊度仪以及光学粒子计数器等仪器对大气气溶胶进行测量。根据球形粒子的Mie散射理论,利用各仪器测量的数据反演得到气溶胶复折射率,并分析了各个地区的粒子谱分布特征,消光系数和吸收系数随波长的变化关系。结果表明,新疆地区、天津地区、厦门地区及合肥地区的大气气溶胶折射率实部n_r都在1.5左右,虚部ni分别为0.01、0.017、0.008和0.016。新疆地区的数浓度谱分布可以用Junge分布来描述,天津地区、合肥地区和厦门地区数浓度谱分布可以用Junge分布和对数正态分布来共同描述。最后还对四地区气溶胶消光和吸收特性随波长的变化关系进行描述,这对于研究气溶胶气候效应具有一定的参考价值。

In order to study the characteristics of aerosol size distribution and complex refractive index in typical areas of China,the atmospheric aerosol was measured by using various equipments like aethalometres,visibility meters,integrating nephelometers and optical particle counter(OPC).The effective complex refractive index based on Mie scattering theory was calculated.Then,the aerosol size distribution was retrieved from the observation,and the relation between extinction and absorption coefficient with respect to wavelength was also analyzed in these typical areas.It shows that the mean values of real of refractive index nr in these area are all around 1.5,while the imaginary parts ni are 0.01,0.017,0.016 and 0.008 in Xinjiang,Tianjin,Hefei and Xiamen,respectively.The number size distribution can be described by Junge size distribution in Xinjiang,while it can be described by both Junge size distribution and lognormal distribution in Tianjin,Hefei and Xiamen.The relation between extinction and absorption characteristics of aerosol and wavelength was described.The results are important for research on the climatic effects of aerosols.