大气气溶胶多层结构的激光雷达探测

Aerosol Multi-layer Vertical Distribution Detected by Lidar

目的探测大气气溶胶的垂直分布,表征气溶胶的垂直结构和各层气溶胶的性质。方法使用金华站点激光雷达观测数据进行个例分析,用梯度法对边界层进行反演,利用退偏振比、颜色比和光学厚度对大气中不同高度的气溶胶层进行分析。结果大气垂直结构会出现多层不同性质的气溶胶层,激光雷达可以准确地探测气溶胶随时间变化的垂直结构特征。选取0点至8点进行分析表明,在1.5km高度上下出现两层气溶胶层,上下两层气溶胶层呈现出不同的性质,且其性质会随时间变化而改变。结论大气边界层以外气溶胶分布较为复杂,利用激光雷达探测的气溶胶消光系数、退偏振比、颜色比和光学厚度等参数能够较好地表征气溶胶的垂直结构和各层气溶胶的性质。

Objective To detect the atmospheric aerosol vertical distribution and characterize the vertical structure of aerosol and the properties of each aerosol layer.Methods Lidar data of Jinhua city was used to have case study.Planetary boundary layer(PBL)was inversed with the gradient method.The proprieties of aerosol layers at different height were analyzed based on parameters of volume depolarization ratio(VDR),attenuated color ratio(ACR)and aerosol optical depth(AOD).Results Multi-layer aerosol could appear in the vertical structure of atmosphere.Lidar can accurately detect the vertical structural characteristics of aerosols over time.Analysis on aerosol layers during 00:00 to 08:00 showed that there were two aerosol layers.One was lower than 1.5 km;and the other was higher than 1.5 km.Besides,the two layers showed diverse characteristics changing with time.Conclusion The aerosol layer outside the PBL shows complex character.The depolarization ratio,extinction and color ratio,optical thickness and other parameters detected through lidar could help to characterize the vertical structure of aerosol and the properties of each aerosol layer.