苏州郊区主要大气污染物的演变特征及其影响因素研究  

Analysis on the Characteristics and Influencing Factors of Major Air Pollutants at A Rural Site in Suzhou

作　　者：鲍孟盈 曹芳[1] 刘寿东[1] 刘晓妍[1] 张园园[1] 张雯淇[1] 汤天然[1] 高雅琦[1] 章炎麟[1] BAO Mengying;CAO Fang;LIU Shoudong;LIU Xiaoyan;ZHANG Yuanyuan;ZHANG Wenqi;TANG Tianran;GAO Yaqi;ZHANG Yanlin(Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science and Technology, Nanjing 210044, China)

机构地区：[1]南京信息工程大学大气环境中心,江苏南京210044

出　　处：《生态环境学报》2017年第1期119-128,共10页Ecology and Environmental Sciences

基　　金：国家自然科学基金项目(91644103);江苏省青年基金项目(BK20150895);南京信息工程大学校人才启动基金项目(2243141601075;2243141501019)

摘　　要：大气灰霾污染已经成为了大气环境领域的研究热点之一,但是目前国内针对背景地区站点的大气污染形成机制和输送规律的研究仍然有限。利用PM_(2.5)、PM_(10)、CO、SO_2、O_3、NO_2等6种大气成分质量浓度数据、常规气象要素观测资料、结合HYSPLIT后向轨迹模式,对2015年1月15—28日发生在江苏省苏州市东山镇的一次持续十余天的空气污染过程进行了分析。结果表明,此次污染过程东山镇经历了一次完整的灰霾生成-积聚-消散的演变过程,其中包括两个主要污染时段,1月15—19日轻污染时段和1月22—26日重污染时段。ρ(PM_(2.5))/ρ(PM_(10))平均值达到62.8%(30.0%~93.4%),表明PM_(2.5)对东山大气颗粒物污染贡献显著。6种大气污染物相关性分析发现CO和NO_2与PM_(2.5)和PM_(10)相关性最好,人为燃烧源和交通源对灰霾形成贡献显著。高空较稳定的环流形势和地面弱气压场的配合以及低压高温高湿的不利气象条件,阻碍了污染物的垂直和水平扩散,是此次持续性灰霾天气形成的客观原因。通过风向、风速统计和后向轨迹分析发现,此次污染过程,在大风下颗粒物以远程输送为主,微风下颗粒物以局地排放为主。外来源的输送和本地源排放的叠加造成了灰霾的形成和积聚。轻污染时段,高浓度污染气团主要来自西北方向的远距离输送,来自山东、河北等工业发达地区的排放源对东山地区灰霾的形成影响显著。重污染时段,污染气团主要来自偏南方向的局地输送,此外来自湖南、江西一带的大规模生物质燃烧生成的高浓度污染气团输送也是污染加重的重要原因。来自东北方向的气流对此次区域灰霾污染起到了清洁作用。China has frequently suffered regional-scale haze pollution in recent years,however,only a few studies have beenconducted at rural sites in China,especially on the transport characteristics of air pollutants between rural sites and surrounded urbanareas.Based on the observation of air pollutants(PM2.5,PM10,SO2,NO2,CO and O3)and conventional meteorological parameters,airpollution problems from January15to28,2015at a rural site(Dongshan)in Suzhou,China were analyzed in this study.The air massback trajectory model(HYSPLIT)was used to identify source of PM2.5.There were two major pollution periods observedcorresponding to slighted polluted period during January15to19and heavily polluted period during January22to26during the wholegeneration-accmulation-dissipation process of the haze formation.PM2.5accounted for62.8%of PM10with the range of30.0%~93.4%,indicating the significant fine particulate matter pollution in Dongshan.Better correlations were found among CO,NO2,PM2.5andPM10,reflecting the common origin of these species from fossil fuel combustion and vehicle emission.Our analysis also showed thatsteady circumfluence and weak pressure on the surface with the meteorological condition of high humidity,high temperature and lowpressure prevented pollutants from dispersing and caused the high pollution level.The analysis on the wind direction and speedshowed that PM2.5concentrations in Dongshan under different wind speed conditions showed different source features.Under highwind speed conditions,strong long-range transport was found,while under low wind speed conditions strong local emissions werefound.The HYSPLIT model analysis showed that both long-range transport from the northwest of Dongshan and local emissions fromthe southeast of Dongshan could significantly contribute to heavy air pollution at Dongshan.During slightly polluted period,highpolluted air masses often originated from industrial provinces(i.e.,Shandong and Hebei)in eastern China.During heavily pollutedperiod,strong local emissions from the southern D

关 键 词：大气污染 PM2.5 气象条件 输送规律 轨迹分析 

分 类 号：X16[环境科学与工程—环境科学]