新冠疫情严控期间南京市空气质量  

Air quality in Nanjing during COVID-19 lockdown period

作　　者：王爱平[1] 朱彬[2] 秦玮[1] 秦艳红[1] 杨雪[1] 刘晓慧[2] WANG Ai-ping;ZHU Bin;QIN Wei;QIN Yan-hong;YANG Xue;LIU Xiao-hui(Jiangsu Environmental Monitoring Centre,Nanjing 210019,China;Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters,Nanjing University of Information Science&Technology,Nanjing 210044,China)

机构地区：[1]江苏省环境监测中心,江苏南京210019 [2]南京信息工程大学,气象灾害预报预警与评估协同创新中心,江苏南京210044

出　　处：《中国环境科学》2021年第7期3088-3095,共8页China Environmental Science

基　　金：江苏省PM2.5和臭氧污染协同控制重大专项(2019023)。

摘　　要：为研究2020年初新冠疫情严控措施对南京市空气质量的影响,选取1月25日~2月10日(疫情严控期)南京及周边省会城市空气质量监测数据,与5a同期数据进行对比,分析时空分布特征.结果表明,疫情停工期间,降水量同比下降,大气扩散条件为近5a较差水平,但除O_(3)浓度不降反升外,其他主要污染物PM_(2.5)、PM10、SO_(2)、NO2和CO浓度均达近5a最低值,分别为36,44,5,22μg/m^(3)和1.1mg/m^(3).通过推算疫情停工期间本地减排措施的“净环境效益”,严控使得PM_(2.5)、PM10、SO_(2)、NO_(2)和CO分别下降了41.7%、45.3%、14.3%、43.5%、18.2%,O_(3)浓度上升了4.8%.从空间上分析,南京市SO_(2)浓度及其同比降幅在长三角省会城市内排名第1,其他污染物改善情况处于中等水平.从日变化可知,PM_(2.5)和PM10日变化由双峰型变为单峰型,夜间未出现次峰值.O_(3)夜间浓度明显升高,原因是交通源的大幅削减使NO对O_(3)的滴定反应降低,而白天O_(3)浓度峰值取决于VOCs和NO_(x)的减排比例.In order to investigate the impact of COVID-19lockdown on air quality in Nanjing,the air pollutants observed from January 25 to February 10,in 2020(COVID-19lockdown period)in Nanjing and its surrounding cities was analyzed.During the lockdown period with poor atmospheric diffusion conditions,the concentrations of PM_(2.5),PM10,NO2,SO_(2),and CO decreased obviously,with the value of 36,44,5,22μg/m^(3) and 1.1mg/m^(3),whereas O_(3) increased by 4%.The net effectiveness of the emission reduction measures was calculated through comparisons of concentrations of air pollutants between and before COVID in the similar meteorological conditions.Concentrations of PM_(2.5),PM10,SO_(2),NO2 and CO decreased by 41.7%,45.3%,14.3%,43.5%and 18.2%,respectively,whereas O_(3) increased by 4.8%.Compared to capital cities of the Yangtze River Delta in the same period,the largest decline of SO_(2) and the medium decline of the other pollutions were appeared in Nanjing.The diurnal variation concentration of PM_(2.5) and PM10 changed from double peak to single peak,due to the disappearance of nighttime sub-peak of particle.The concentration of O_(3) increased significantly at night,which was resulted from that sharp reduction of traffic sources weaken the titration reaction of NO to O_(3).The peak of O_(3) during the daytime depended on the variation of the ratio of VOCs to NO_(x) due to the emission control.

关 键 词：南京 新冠疫情 空气质量 减排 

分 类 号：X511[环境科学与工程—环境工程]