大气气溶胶粒径分布的多波长激光雷达反演  

Retrieval of Aerosol Particle Size Distribution from Multi-Wavelength Lidar

作　　者：李晓涛 刘东[1,2,3,4] 肖达 张凯 胡先哲[1] 李蔚泽 毕磊 孙文波 吴兰 刘崇[1] 邓洁松[1] Li Xiaotao;Liu Dong;Xiao Da;Zhang Kai;Hu Xianzhe;Li Weize;Bi Lei;Sun Wenbo;Wu Lan;Liu Chong;Deng Jiesong(State Key Laboratory of Extreme Photonics and Instrumentation,College of Optical Science and Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China;Donghai Laboratory,Zhoushan 316021,Zhejiang,China;Intelligent Optics&Photonics Research Center,Jiaxing Research Institute,Zhejiang University,Jiaxing 314000,Zhejiang,China;Hangzhou Global Scientific and Technological Innovation Center,Zhejiang University,Hangzhou 311200,Zhejiang,China;Key Laboratory of Geoscience Big Data and Deep Resource of Zhejiang Province,School of Earth Sciences,Zhejiang University,Hangzhou 310027,Zhejiang,China)

机构地区：[1]浙江大学光电科学与工程学院极端光学技术与仪器全国重点实验室,浙江杭州310027 [2]东海实验室,浙江舟山316021 [3]浙江大学嘉兴研究院智能光电创新中心,浙江嘉兴314000 [4]浙江大学杭州国际科创中心,浙江杭州311200 [5]浙江大学地球科学学院浙江省地学大数据与地球深部资源重点实验室,浙江杭州310027

出　　处：《光学学报》2024年第6期157-164,共8页Acta Optica Sinica

基　　金：国家重点研发计划(2022YFB3901704,2022YFC2203904,2021YFC2202001);国家自然科学基金(62205289);浙江省自然科学基金(LQ23F050011);中央引导地方科技发展资金项目(2022ZYYDSAA00273)。

摘　　要：提出一种基于正则化方法改进的气溶胶微物理特性反演算法,通过引入模式半径范围作为先验约束,并对差异最小值附近的解进行平均,以解决反演时存在的欠定问题。对1500组不同类型的气溶胶粒径分布进行仿真,测试了所提反演算法对气溶胶微物理特性参数的反演精度与稳定性。考虑在20%随机高斯噪声的影响下,90%以上气溶胶的有效半径、体积浓度和表面积浓度反演相对误差可被控制在±33%、±45%和±50%范围内。误差统计结果表明,所提算法基于多波长的气溶胶光学特性,可实现对气溶胶粒径分布的可靠反演。Objective Atmospheric aerosols play a crucial role in climate change and atmospheric pollution.Multi-wavelength Raman lidars and lidars with high spectral resolution can accurately measure aerosol extinction and backscatter coefficients for retrieving aerosol particle size distribution,volume concentration,effective radius,and other microphysical properties,which is significant for studying regional and global ecological environments.However,retrieval errors exist in the extinction and backscattering coefficients detected by lidars.When the aerosol microphysical properties are retrieved,the number of unknown parameters required to be solved is often greater than that of optical measurement channels,which is a typical ill-posed inverse problem.As the retrieved results show significant uncertainty in some cases,additional constraints should be introduced to improve the retrieval stability.We propose an advanced regularization retrieval algorithm that introduces a priori mode radius range as a constraint to improve the retrieval accuracy of particle size distribution parameters of different aerosol types.Methods In our study,an advanced retrieval algorithm for aerosol microphysical properties based on the regularization method is developed.The entire algorithm process is shown in Fig.1.Based on the Tikhonov regularization retrieval,the reliable retrieval of microphysical particle properties can be realized with a combined data set of particle backscattering coefficients at 355,532,and 1064 nm and extinction coefficients at 355 nm and 532 nm.Generally,only those solutions for which the optical discrepancy term takes its minimum are selected in retrieval,but here all individual solutions that are within a certain range around this minimum solution are averaged.As a result,the retrieval stability can be improved.Additionally,referring to the aerosol models from the AERONET database,we obtain the volume mode radius ranges of coarse and fine mode aerosols.By employing this as a priori constraint,further selection is perf

关 键 词：大气光学 多波长激光雷达 正则化方法 气溶胶粒径分布 微物理特性 

分 类 号：P407[天文地球—大气科学及气象学]