探究影响南京地区大气气溶胶光学特性反演的因素

Influence Factors on Atmospheric Aerosol Optical Property Inversion in Nanjing

对南京地区大气气溶胶的光学特性进行了反演,讨论了影响大气气溶胶消光系数反演准确度的不同因素。采用不同的方法对信号进行去背景处理,找出合适的去噪方法;利用五点三次平滑、小波去噪、十一点平滑等方法对去噪后的信号进行再处理,找出可以得到准确反演结果的方法。分析了Klett方法中的后向消光对数比与参考高度处的消光系数对反演结果的影响,分别对k的取值范围为0.671.0、σm的取值在1×10^(-5) km^(-1)附近的反演结果进行了分析,在Fernald方法中分析激光雷达比的取值(范围为2070)对反演结果的影响。对Klett与Fernald两种方法的计算结果进行了对比,发现在大气气溶胶含量低的区域,两种方法反演结果有差别,而在大气气溶胶含量较高区域,两种方法反演结果几乎相同。

The optical property of atmospheric aerosol in Nangjing is inversed, and the different factors which can influence the inversion accuracy of extinction coefficient of atmospheric aerosol are studied. The de-noising processing for signal is carried out by different methods, and the suitable de-noising method is found. The reprocessing for de-noised signal is carried out with five-point triple smoothing, wavelet de-noising and eleven-point smoothing respectively, and the method which can obtain accurate inversion result is chosen. The effects of logarithmic ratio of backscatter extinction and extinction coefficient at the reference height on the inversion result of Klett method are analyzed. The inversion results when k ranges from 0.67 to 1.0 and an, is about 1 X 10-s km-1 are analyzed. The influence of the lidar ratio on the inversion result of Fernald method is analyzed when the lidar ratio ranges from 20 to 70. The results of Klett method are compared with that of Fernald method. It is found that in the region with low atmospheric aerosol content, the results of the two methods are different, but the results of the two methods are almost same in the region with high aerosol content.