Impact of meteorological condition changes on air quality and particulate chemical composition during the COVID-19 lockdown

作     者：Jing Ding Qili Dai Yafei Li Suqin Han Yufen Zhang Yinchang Feng Jing Ding;Qili Dai;Yafei Li;Suqin Han;Yufen Zhang;Yinchang Feng

作者机构：Tianjin Environmental Meteorological CenterTianjin 300074China State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and ControlCollege of Environmental Science and EngineeringNankai UniversityTianjin 300350China CMA-NKU Cooperative Laboratory for Atmospheric Environment-Health ResearchTianjin 300074China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2021年第33卷第11期

页      面：45-56页

核心收录：

学科分类：07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 

基　　金：supported by the Tianjin Natural Science Foundation(No.18JCYBJC23100) the Tianjin Science and Technology Foundation(No.18ZXSZSF00160) the National Natural Science Foundation of China(No.41771242) the China Postdoctoral Science Foundation(No.2019M660984) 

主　　题：COVID-19 lockdown Air quality Meteorological condition Air humidity Aerosol chemistry 

摘      要：Stringent quarantine measures during the Coronavirus Disease 2019(COVID-19)lockdown period(January 23,2020 to March 15,2020)have resulted in a distinct decrease in anthropogenic source emissions in North China Plain compared to the paralleled period of ***,22.7%decrease in NO_(2)and 3.0%increase of O_(3)was observed in Tianjin,nonlinear relationship between O_(3)generation and NO_(2)implied that synergetic control of NOx and VOCs is *** meteorological condition during the COVID-19 lockdown obscured the actual PM2.5 *** transport in 2020 Spring Festival(SF)triggered regional haze ***2.5 during the COVID-19 lockdown only reduced by 5.6%in *** we used the dispersion coefficient to normalize the measured PM2.5(DN-PM2.5),aiming to eliminate the adverse meteorological impact and roughly estimate the actual PM2.5 reduction,which reduced by 17.7%during the COVID-19 *** terms of PM2.5 chemical composition,significant NO_(3)−increase was observed during the COVID-19 ***,as a tracer of atmospheric oxidation capacity,odd oxygen(Ox=NO_(2)+O_(3))was observed to reduce during the COVID-19 lockdown,whereas relative humidity(RH),specific humidity and aerosol liquid water content(ALWC)were observed with noticeable *** oxidation rate(NOR)was observed to increase at higher specific humidity and ALWC,especially in the haze episode occurred during 2020SF,high air humidity and obvious nitrate generation was *** enhanced air humidity may response for the nitrate increase during the COVID-19 lockdown period.