Atmospheric oxidizing capacity in autumn Beijing:Analysis of the O_(3) and PM_(2.5) episodes based on observation-based model  

作　　者：Chenhui Jia Shengrui Tong Xinran Zhang Fangjie Li Wenqian Zhang Weiran Li ZhenWang Gen Zhang Guiqian Tang Zirui Liu Maofa Ge 

机构地区：[1]State Key Laboratory for Structural Chemistry of Unstable and Stable Species,CAS Research/Education Center for Excellence in Molecular Sciences,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Center for Excellence in Regional Atmospheric Environment,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China [4]College of Chemistry,Liaoning University,Shenyang 110036,China [5]State Key Laboratory of Severe Weather&Key Laboratory for Atmospheric Chemistry of CMA,Institute of Atmospheric Composition,Chinese Academy of Meteorological Sciences,Beijing 100081,China [6]State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China

出　　处：《Journal of Environmental Sciences》2023年第2期557-569,共13页环境科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China (No. 2017YFC0210001);the National Natural Science Foundation of China (Nos. 41830106, 42022039);Beijing National Laboratory for Molecular Sciences (No. BNLMS-CXXM-202011);the Youth Innovation Promotion Association CAS (No. 2017042)

摘　　要：Atmospheric oxidizing capacity(AOC)is the fundamental driving factors of chemistry process(e.g.,the formation of ozone(O_(3))and secondary organic aerosols(SOA))in the troposphere.However,accurate quantification of AOC still remains uncertainty.In this study,a comprehensive field campaign was conducted during autumn 2019 in downtown of Beijing,where O_(3) and PM_(2.5) episodes had been experienced successively.The observation-based model(OBM)is used to quantify the AOC at O_(3) and PM_(2.5) episodes.The strong intensity of AOC is found at O_(3) and PM2.5 episodes,and hydroxyl radical(OH)is the dominating daytime oxidant for both episodes.The photolysis of O_(3) is main source of OH at O_(3) episode;the photolysis of nitrous acid(HONO)and formaldehyde(HCHO)plays important role in OH formation at PM_(2.5) episode.The radicals loss routines vary according to precursor pollutants,resulting in different types of air pollution.O_(3) budgets and sensitivity analysis indicates that O_(3) production is transition regime(both VOC and NOx-limited)at O3 episode.The heterogeneous reaction of hydroperoxy radicals(HO_(2))on aerosol surfaces has significant influence on OH and O_(3) production rates.The HO_(2) uptake coefficient(γHO_(2))is the determining factor and required accurate measurement in real atmospheric environment.Our findings could provide the important bases for coordinated control of PM_(2.5) and O_(3) pollution.

关 键 词：Pollution episode Observation-based model Atmospheric oxidizing capacity Heterogeneous reaction Hydroxyl radical Budgets 

分 类 号：X51[环境科学与工程—环境工程]