中国典型地区气溶胶激光雷达比反演与分析

Retrieval and Analysis of Aerosol Lidar Ratio at Several Typical Regions in China

为了解决大部分微脉冲激光雷达无法独立获取激光雷达比的问题,利用榆林、北京、寿县和太湖4个地区气溶胶监测网(AERONET)站点观测的气溶胶粒子谱分布和复折射指数产品,通过米氏散射方法计算得到气溶胶激光雷达比。根据得到的长时间序列气溶胶激光雷达比分析了不同地区激光雷达比的季节变化和年变化特征,并结合Angstrom波长指数对不同地区气溶胶类型进行了简单分析。得到了以下结论:不同地区同季节以及同地区不同季节激光雷达比相差较大;观测期间榆林地区年平均激光雷达比最小,多年平均值为(36.3±15)sr;北京、太湖和寿县地区的雷达比年均值较大;北京地区激光雷达比年均值的最低值出现在2008年,其他地区的年均值变化不大;激光雷达比与Angstrom波长指数能够区分各地区气溶胶主要类型且均出现由北到南递增的趋势。

In order to solve the problem that most of micro-pulse lidars cannot obtain lidar ratio （LR） independently, LR from aerosol size distribution and complex refractive index is acquired with Mie scattering theory. Four aerosol robotic network （AERONET） stations that include SACOL station, Beijing station, Shouxian station and Taihu station are used. The LR variation characteristics of seasonal-mean and years＇ average values in different regions and aerosol types are analyzed by using LR and Angstrom wavelength index, The conclusions are as follows： LRs in chinese different regions and seasons show complex and different variation characteristics; the LR in Yulin is the least and years＇ average value is （36.3±15）sr; LRs are relatively larger in Taihu, Beijing and Shouxian; annual average value of 2008 is smaller than other years in Beijing and there is little variation of years＇ average value in other regions. LR and Angstrom wavelength index can distinguish aerosol type and they both increase from north to south in the analysis regions.