Simultaneous Retrieval Of Atmospheric Ozone And Aerosol Based On Three Wavelength Lidar

The pollution caused by aerosol and ozone in the atmosphere is the main air pollution faced by China.The prevention and control of air pollution needs richer detection data to analyze the causes of pollution,and the severe pollution prevention and control situation also puts forward higher requirements for the detection means of air pollutants.As an active remote sensing detection means,lidar can obtain the spatiotemporal distribution information of atmospheric aerosol and ozone with high spatiotemporal resolution,and can provide strong support for the prevention and control of air pollution.However,in lidar atmospheric detection,ozone and aerosol will interfere with each other,affecting the retrieval accuracy of the two pollutants.In order to better apply lidar to the prevention and control of air pollution,this paper has done the following work on the lidar inversion method of pollutants:(1)The influence of lidar ratio on the inversion results in the aerosol inversion process is analyzed,and it is proposed to use the long-term Raman scattering lidar observation results to calculate the average aerosol lidar specific profile,and use the lidar specific profile to improve the inversion accuracy of the aerosol detection results of the conventional Mie scattering lidar.After the aerosol detection accuracy is improved by this method,it is applied to the analysis of pollution process.(2)The difference of depolarization ratio between dust aerosol and spherical aerosol measured by Mie scattering lidar is proposed,and the contribution rate of dust aerosol in the mixed aerosol of dust and local pollutants is calculated,so as to inverse the optical characteristics of dust aerosol in the process of dust.Combined with the observation data of wind profile Lidar,dust transport flux in dust process has been calculated.(3)By analyzing the influence of aerosols on the Dual-DIAL method,find that Dual-DIAL method can effectively eliminate the interference between aerosols and ozone in the inversion process,so as to retrieve ozone and aerosols synchronously.The Dual-DIAL method is used to retrieve the atmospheric ozone concentration,which can effectively reduce the impact of atmospheric aerosols.Compared with the conventional DIAL method,the error can be reduced by 10 times.(4)The inversion method of aerosol particle spectrum distribution using multi wavelength lidar under Junge distribution and lognormal distribution is studied.Under these two particle spectrum assumptions,three wavelength lidar are used for particle spectrum inversion respectively.A method of simultaneous inversion of particle spectrum using three wavelength lidar with wavelength in ozone absorption band is proposed.Using this method,atmospheric ozone concentration and aerosol particle spectrum can be retrieved synchronously.Through the above work,the inversion accuracy of atmospheric aerosol and ozone in lidar atmospheric detection is improved,and the synchronous inversion of atmospheric aerosol and ozone concentration is realized,which can effectively support the prevention and control of air pollution and provide a new means for the research of collaborative control of aerosol and ozone.