摘要:利用3个架次的积分浊度仪和PCASP-100X（Passive Cavity Aerosol Spectrometer Probe）机载观测资料，分析了2013年山西夏季空中有云、无云和少云3种不同条件下气溶胶散射系数的分布特征，讨论了气溶胶散射系数垂直变化与气溶胶数浓度、气象条件的关系，并结合HYSPLIT（Hybrid of Single Particle Lagrangian Integrated Trajectory model）后向轨迹模型研究气溶胶的运动轨迹和可能的污染来源。结果表明：山西夏季空中气溶胶总散射系数变化范围为0～499 Mm-1，晴空气溶胶数浓度和总散射系数明显大于有云和少云时。气溶胶总散射系数一般随高度的增加而递减。造成气溶胶总散射系数、数浓度偏高的原因有下垫面污染源多、风速小、相对湿度高以及逆温层的存在。550 nm波段气溶胶后向散射比大于0.1，粒径0.1～0.5 μm的气溶胶粒子对散射影响最大，说明山西空中细粒子污染比较严重。气溶胶总散射系数与数浓度有一定的相关性。引起气溶胶总散射系数、数浓度较高的气团传输路径主要为西南路径，局地排放的气溶胶大于远距离传输的气溶胶对散射系数的贡献。
关键词:气溶胶/
散射特性/
飞机观测/
山西
Abstract:The aerosol total scattering coefficient and its relation to the aerosol number concentration and meteorological conditions on cloudy, sunny, and cloudless days were analyzed using the integrating nephelometer and PCASP(Passive Cavity Aerosol Spectrometer Probe)-100X of three aerosol detection flights over Shanxi Province in the summer of 2013. The movement tracks and possible sources of aerosol pollution were discussed using the HYSPLIT(Hybrid of Single Particle Lagrangian Integrated Trajectory) model. The results showed that the range of aerosol total scattering coefficient varied from 0 Mm-1 to 499 Mm-1. The aerosol total scattering coefficient and aerosol number concentration on sunny days were significantly higher than those on cloudy and cloudless days. The aerosol total scattering coefficient decreased with altitude. Given the multiple pollution sources in the underlying surface, low wind speed, high relative humidity, and existence of a temperature inversion layer, the aerosol total scattering coefficient and aerosol number concentration increased. The ratio of the backscattering coefficient of the 550 nm wavelength was larger than 0.1. The aerosol total scattering coefficient was mainly influenced by the particle size of 0.1-0.5 μm, indicating that a significant fraction of particulate matter in Shanxi Province was attributed to fine-grained particles. Furthermore, the air pathways, which caused the high aerosol total scattering coefficient and aerosol number concentration, are mainly from the southwest. The contribution of local near-surface sources to aerosol total scattering coefficient is greater than that of long-distance transmission.
Key words:Aerosols/
Scattering properties/
Aircraft measurements/
Shanxi Province
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