微脉冲激光雷达反演半干旱区气溶胶消光系数方法

Method for Inverting Aerosol Extinction Coefficient using Micro Pulse Lidar Data in the Semi-arid Regions of China

利用位于甘肃省榆中县兰州大学半干旱区气候与环境观测站的微脉冲激光雷达2008年春季的有效观测数据,对微脉冲激光雷达在半干旱区应用时不同反演方法的差别、参数的选取以及反演结果的差异及可能出现的原因进行了讨论。认为Klett法和Fernald法均能反映出大气气溶胶垂直分布的空间和时间特征,且结果较为一致。在晴朗无云及沙尘天气时,两种方法对于低层大气气溶胶消光系数反演结果基本相同,在接近实际探测高度时结果差异较大。有云天气下,Fernald法对于低层气溶胶的消光系数的反演结果同Klett法相比较小,在接近实际探测高度时差异较大。实际应用中,在半干旱地区利用微脉冲激光雷达对气溶胶消光系数进行反演时,对于高层气溶胶的信息获取,采用Klett法更为合理。

Using the effective observation data during the spring of 2008 from Micro Pulse Lidar at Semi-Arid Climate and Environment Observatory of Lanzhou University in Yuzhong,Gansu,China,the difference and possible causes for inverting aerosol extinction coefficient by Klett's method and Fernald's method are discussed.Klett's method and Fernald's method can reflect the characteristics of atmospheric aerosol extinction coefficient vertical distribution,and the results are consistent.On the cloudless and the dusty days,the inversion results at low altitude are basically the same,and the results show a great difference at the maximum detection height.On the cloudy day,the inversion results at low altitude by Fernald's method were smaller than that by Klett's method,and difference increases at the maximum detecting height.In practical application,to invert aerosol extinction coefficient in semi-arid regions using the Micro Pulse Lidar,Klett's method is more reasonable if we need to know the aerosol information at high altitude.