Evolution And Transport Characteristics Of Ozone And Its Precursors In Boundary Layer Based On Ground-based Hyperspectral Remote Sensing

The concentration of particulate matter has gradually decreased in China since 2013;however,ozone concentrations continue to rise.It is urgent to strengthen the coordinated management of ozone and fine particulate matter during the "14th FiveYear Plan" period.Ozone and particulate matter are important secondary pollutants,and their generation occurs near the ground and at high altitudes.Regional transport of ozone and its precursors can directly lead to the outbreaks of regional pollution events,with the contribution of atmospheric physical processes such as turbulence and wind.Air pollution joint prevention,and coordinated management of ozone and fine particulate matter are further needed in future.Ground-based hyperspectral remote sensing can simultaneously observe the vertical distribution of various atmospheric pollutants,which is also playing an increasingly important role in environmental monitoring area.The vertical profile inversion algorithm is relatively well established;however,it can not directly be used for vertical ozone profile retrieval due to the interference induced by stratospheric ozone.This paper establishes an algorithm for tropospheric ozone and its precursor profile retrieval based on the ground-based hyperspectral remote sensing technology.Then we performed the sensitivity tests to derive a set of useful parameters for the inversion algorithm.In this paper,the study of spatiotemporal evolution of ozone and its precursors,and the ozone formation sensitivity are carried out in Beijing area.We obtained the evolution characteristics of particulate matter,ozone and their precursors at different altitude,and discussed the vertical structure of ozone formation sensitivity.The regional transport flux profiles in Fen-Wei Plain were obtained in this study.We concluded the regional transport characteristics in winter,and discussed the transport contributions to local air quality from two privilege wind directions.The main conclusions in this paper are listed here:1.We established an inversion algorithm for tropospheric ozone and precursor profile retrieval.In this algorithm,a set of spatiotemporal dependent ozone a prior profiles and stratospheric profiles from independent data set are used to reduce the interference induced by stratospheric ozone.The independent measurements,including CNEMC,ozonesonde,were used to validate the ozone profile results.2.We derived a set of useful parameters for spectral analysis,radiative transfer simulation and profile inversion.The algorithm is applied for observations within two instruments during same period,the ozone profile results are consistent,which indicates the stability and reliability of the inversion algorithm.3.Spatiotemporal evolution of ozone and its precursors,and the vertical structure of ozone formation sensitivity in Beijing were studied in this paper.Evolution characteristics of various pollutants are most obvious at near surface,which is related to the traffic emission.For the vertical structure of ozone formation sensitivity during the summer of 2018:ozone formation is mixed limited in near-surface and upper boundary layer;while ozone formation is NOx limited for middle boundary.4.We characterized the vertical structures of transport fluxes in central Luoyang,Fen-Wei Plain,China in winter based on observations of vertical air pollutant and wind profiles using ground-based hyperspectral remote sensing and Doppler wind Lidar,respectively.Northwest and northeast transport pathways were dominant.Surfacedominated northeast transport promoted the accumulation of pollutants during haze events,while northwest transport characterized by mainly transport altitude at 200-600 m altitude dominated transport during clear days and helped dissipate air pollutants in Luoyang.