Detection and Analysis of Aerosol Micro-physics Properties Using Multi-wavelength Polarization Lidar
作者单位：School of Mechanical and Precision Instrument Engineering Xi’an University of Technology
会议名称：《第十八届中国科协年会——分12大气雾霾及PM2.5...》
会议日期：2016年
学科分类：083002[工学-环境工程] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 08[工学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 0713[理学-生态学]
关 键 词：Aerosol multi-wavelength lidar haze polarization
摘 要：Lidar is a powerful tool for remotely studying temporal and spatial variations of aerosol in atmosphere. Mie-scattering lidar which measures the total backscattered laser light from the atmosphere is used worldwidely for studying aerosol optical properties. The aerosol backscatter optical property is uniquely determined according to the physical and chemical properties of the aerosols(their size, shape, and complex refractive index) and the laser wavelength, and the wavelength dependence of the backscatter and extinction coefficient is mainly dependent on the aerosol size distribution and refractive index. The micro physical characteristics of aerosol can be retrieved according to multi-wavelength optical signals. The retrieval method of aerosol microphysical character was developed based on the concept of Tikhonov’s regularization. A multi-wavelength polarization lidar was built at the Lidar Center for Atmosphere Remote Sensing, in Xi’an, China to study the vertical distribution of the optical and microphysical properties of aerosols. And the atmosphere observations were carried out in January 2015. An smog event was studied and analysed in detail. Using inversion with regularization, we retrieved the vertical distribution of aerosol microphysical properties, including volume size distribution, volume concentration, number concentration and effective radius. We also used the Hybrid Single Particle Lagrangian Integrated Trajectory(HYSPLIT) model to analyse aerosol sources during the episode. In the case of severe smog, we found a large number of spherical and fine particles concentrated in the very low troposphere, even below 0.5 km. Surprisingly, a dust layer with a slight depolarization ratio was observed above the smog layer.