一次阴雨条件下河北中南部气溶胶的参数特征分析

An Airplane Detection of Aerosol over the Middle-South of Hebei Province on Rainy Day

利用2009年9月8日华北中南部上空的飞机探测资料,分析了石家庄市和邯郸市区附近大气气溶胶的粒子数浓度、直径、尺度谱分布等时空变化特征。分析表明,降水天气条件下,气溶胶粒子平均数浓度约为137.6个/cm3,平均直径约为0.26μm。气溶胶主要集中于2 000 m以下的对流层低层,气溶胶浓度总体上随高度增加而降低;雨后阴天轻雾天气条件下,气溶胶粒子平均数浓度约为164.7个/cm3,平均直径约为0.16μm。气溶胶在逆温层下累积现象明显,云内气溶胶数浓度明显减少。气溶胶粒子浓度水平变化受下垫面、云区分布等局地因子影响较大。石家庄600 m和6 600 m气溶胶粒子谱呈单峰分布,3 000 m粒子谱呈双峰分布。邯郸6 400 m粒子谱宽较窄,呈单峰分布。

Based on the airplane detection data over the middle - south of Hebei Province on Sept 8, 2009, the aerosol particle concentration, diameter and the particle spectrum distributions over Shijiazhuang and Handan were analyzed. The results indicate that the aerosol average number concentration was 137.6/cm3 and the average diameter was 0.26 p,m under rainy weather condition. The aero- sol particles mainly concentrated on the low troposphere below 2 000 m, and the aerosol number concentration decreased with height. The aerosol average number concentration was 164.7/cm3 and the average diameter was 0.16 μm under cloudy and foggy weather condition after precipitation. The aerosol accumulated distinctly on the bottom of inversion temperature layer, and the aerosol number concentrations decreased significantly inside the cloud. The aerosol particle concentration was very sensitive to the underlying surface and the distribution of cloud area. The aerosol particle spectrum on the level of 600 m and 6 600 m presented unimodal pattern, and on the 3 000 m level it presented bimodal change over Shijiazhuang. The aerosol particle spectrum on the level of 6 400 m presented unimodal change and the spectral width was narrow over Handan.