颗粒物分界层Mie散射激光雷达识别的sigmoid算法

基于成都市2013年6月~2015年5月期间由Mie散射激光雷达探测的大气消光系数廓线资料，发现混合层以上在颗粒物消光和分子消光之间一致存在一个S型的过渡区，利用sigmoid函数对此分布形态进行模拟，通过计算该函数上下曲率最大点所在的高度，据此提出了颗粒物分界层Mie散射激光雷达识别的sigmoid算法.针对该算法模拟效果的分析表明，颗粒物分界层过渡区附近大气消光系数理论廓线和实测廓线保持了高度的相关性，二者在春夏秋冬四季的相关系数（R）分别为0.9971±0.0052、0.9935±0.0167、0.9979±0.0038和0.9990±0.0021（均通过α=0.05的显著性检验）.基于sigmoid算法计算的颗粒物分界层过渡区与成都市温江站探空资料得到的逆温层之间存在很好的对应关系.

Sigmoid algorithm for calculating particle boundary layer based on mie scattering lidar

Based on the data of atmospheric extinction coefficient detected by Mie scattering lidar from June 2013 to May 2015 of Chengdu, it was found that there was a S-shaped transitional zone between aerosol extinction and molecular extinction above mixing layer, and sigmoid function was used to simulate this vertical distribution. By obtaining the heights of the upper and lower maximum curvature points of the function, a sigmoid algorithm for calculating the transition zone of particle boundary layer based on Mie scattering lidar was proposed. The results showed that, as to the atmospheric extinction coefficient in the transition zone and its vicinity, simulated profiles and measured ones maintained a significant correlation, and the correlation coefficients of the two in spring, summer, autumn and winter were 0.9971±0.0052, 0.9935±0.0167, 0.9979±0.0038 and 0.99895±0.0021 respectively (Passing the significance test of 0.05). Further researches indicated that there existed a good correspondence between the transition zone of particle boundary layer calculated by sigmoid algorithm and the inversion layer identified by sounding data in Wenjiang station.