基于CALIPSO卫星监测的重庆地区霾微物理特性研究

Microphysical Properties of Haze over Chongqing Area Based on CALIPSO Observation

采用美国国家航空航天局（NASA）的CALIPSO星载激光雷达L1监测数据，通过分析532nm总后向系数、体积退偏比和色比，对重庆地区对流层中低空霾的气溶胶散射强度、粒子规则性和相对大小的垂直分布及其季节变化进行了研究。结果表明：对于4km以下的对流层中低空霾，大气气溶胶的散射能力大致随着高度增加而减弱，其中1～2km的气溶胶散射能力最强，0～2km规则、大颗粒气溶胶所占比例最大，3～4km不规则、细颗粒气溶胶所占比例最大。春季重庆地区的不规则、大颗粒气溶胶所占比例大，夏季以规则气溶胶为主，气溶胶散射能力较弱，秋季的规则、细粒子气溶胶相对较多，冬季则以细颗粒气溶胶为主，气溶胶散射能力较强。分析2008年4月8日个例发现，气溶胶粒子大量聚集在1．6～3．4km范围内，2～3km的大气气溶胶散射能力最强，0～2km以规则、大颗粒气溶胶占主导，2～4km的不规则、细颗粒气溶胶所占比例最大。

Using the onboard lidar data from CALIPSO satellite of National Aeronautics and Space Administration （NASA）, the vertical distribution of aerosol scattering intensity, particle regularity and relative size and the seasonal variation of aerosols in middle and low troposphere in Chongqing area during haze periods were revealed by analyzing the parameters of total 532nm attenuated backscatter coefficient, volume depolarization ratio and total attenuated color ratio. Results showed that during haze periods, the scattering ability of atmospheric aerosols in middle and low troposphere below 4 km generally decreased with increasing altitude and that in lower troposphere （1-2 km） was the strongest. The proportion of regular aerosols and large particles were the most in low troposphere （0-2 km） and the proportion of irregular aerosols and small particles were the most in middle troposphere （3-4 kin）. The proportion of irregular aerosols and large particles were large in spring but regular aerosols were dominant aerosols in summer. The proportion of regular aerosols and small particles were large in autumn and that of small particles was large in winter. According to the analysis of a haze episode on April 8th, 2008, it was found that a mass of aerosols was centralized within the altitude range of 1.6～3.4 km and the scattering ability of atmospheric aerosols in the troposphere of 2～3 km was strongest. Regular aerosols and large particles were dominant aerosols in low troposphere （0～2 kin） and the proportion of irregular aerosols and small particles were large in the troposphere of 2～4 km.