上海市2020年初黑碳污染特征分析

Analysis on the Pollution Characteristics of Black Carbon in Shanghai at the Beginning of 2020

黑碳是气溶胶的重要组分,影响着大气环境质量。自20世纪70年代以来,国际上开始探索极地地区黑碳气溶胶的污染特征,并将其列为气候变化的重要研究课题之一。该文选择上海市浦东新区灵山路、青浦区淀山湖、奉贤区海湾作为3个观测区域,分析了2020年1月15日-2月29日(新型冠状病毒肺炎疫情国内爆发期)黑碳的污染特征及其影响因素;结合2015-2020年期间浦东新区、青浦区和奉贤区环境空气质量历史数据,比较了新型冠状病毒肺炎疫情期间黑碳的排放特征。结果显示:疫情爆发期间,黑碳浓度先下降后上升,说明城市交通源排放是黑碳的主要来源;上海市城市大气中黑碳气溶胶浓度除受本地交通源影响较大外,一定程度也受外部输入的影响(包括北方重污染长距离输入和附近省市交通源污染的输入)。同时发现,疫情期间O_(3)作为首要污染物的天数大幅增多,远多于以PM_(2.5)为首要污染物的天数。

As an important component of aerosols,black carbon(BC)could affect the quality of the atmospheric environment.The properties of BC in Antarctic and Arctic regions have been explored internationally since the 1970 s,and the pollution characteristics and influencing factors of black carbon in atmospheric aerosols were systematically investigated.In the present study,three different observation points were selected in Shanghai,which located in Lingshan Road at Pudong New District,Dianshan Lake at Qingpu District,Bay in Fengxian District.BC concentrations were collected online synchronously from 15 th in January to 29 th in February in 2020 during the COVID-19 epidemic situation.BC emission characteristics were systematically analyzed by comparison with the historical data of air environmental quality.The result revealed that BC concentration declined drastically at the initial stage of COVID-19 epidemic,afterwards,it increased gradually,indicating that traffic sources dominated in BC emission.In addition,external input was also found to contribute to the BC emission,which included the long-distance heavy pollution from the north and the traffic source pollution from nearby provinces and cities.Moreover,instead of PM_(2.5),ozone(O_(3))was found to be the primary pollutant in Shanghai during the epidemic period.