2006~2015年中国华北地区气溶胶的垂直分布特征

为研究高污染地区气溶胶形成机理提供理论依据，利用CALIPSO卫星提供的Level 2Profile和Level 2VFM产品，分析了华北地区2006～2015年532nm总后向散射系数，退偏振比，色比及不同类型气溶胶的时空变化特征，并结合地基观测资料，探讨了不同能见度下华北地区气溶胶垂直分布特征.结果表明：华北地区气溶胶粒子532nm总后向散射系数，退偏振比和色比范围依次为0.5×10^-3～8.0×10^-3km^-1sr^-1，0.14～0.3和0.6～2.0，且具有显著的季节和高度变化特征；能见度<5km时粒子散射能力最强，非球形最弱，粒径最小，对应的最大532nm总后向散射系数，最小退偏振比和最小色比依次为0.012km^-1sr^-1，0.092和0.856，能见度>10km时相反；污染沙尘，沙漠沙尘，污染大陆气溶胶和洁净海洋气溶胶集中在0～2km，出现的频率依次为13.81%，8.48%，5.45%和1.22%.

Vertical distribution of atmospheric aerosol particles over North China from 2006 to 2015

To provide theoretical basis for studying the formation mechanism of aerosol, this paper analyzes the spatial and temporal variation characteristics of 532nm total backscatter coefficient, particulate depolarization ratio, color ratio, and different types of aerosol over North China from 2006 to 2015 by using Level 2 profile and Level 2VFM products provided by CALIPSO system.Vertical distribution characteristics of aerosol under different visibility conditions are then analyzed over North China based on surface observation data. The results show that 532nm total backscatter coefficient, particulate depolarization ratio, and color ratio over North China range from 0.5×10^-3~8.0×10^-3km^-1·sr^-1, 0.14~0.3, and 0.6~2.0, respectively, which all shows characteristics of significant variation with season and height. In addition, aerosol particles have a stronger scattering ability, more regular shape, and smaller sizes with visibility of less than 5km than more than 5km and vice versa with visibility of more than 10km. When the visibility is less than 5km, the corresponding maximum 532nm total backscatter coefficient, minimum particulate depolarization ratio, and minimum color ratio are 0.012km^-1·sr^-1, 0.092, and 0.856, respectively. The results also show that the aerosols of polluted dust, dust in desert, polluted continental and clean marine concentrate between 0 to 2km, whose occurrence frequencies are 13.81%, 8.48%, 5.45%, and 1.22%, respectively.