摘要
为探究珠江三角洲典型城市东莞市黑碳气溶胶(BC)的污染特征,对东莞市气象局站点2010年1月1日至2010年12月31日观测得到的BC数据进行了处理,并分析了东莞市2010年全年BC的分布特征、日变化规律以及污染来源。结果表明,(1)东莞站点BC浓度的频率分布为对数正态分布,BC的年均浓度为(3.98±3.42)μg/m^3,背景浓度为(1.14±1.04)μg/m^3。BC浓度湿季相对较低,干季相对较高。与国内各大城市相比,污染程度较轻,与背景站和一些国外城市相比,该站点处的BC污染问题较为严重;(2)BC浓度的日变化呈明显的两峰一谷型,表明BC浓度的日变化特征是由气象条件和交通源的日变化规律共同影响;(3)观测期间,370~950 nm波段的波长吸收指数(AAE370~950)的频率分布为对数正态分布,年均值为1.02,年变化呈现湿季减小、干季增大的变化趋势;(4)BC浓度和风速的关系表明,BC浓度随着风速的增大而减小,说明风对BC浓度起到稀释扩散的作用;(5)后向轨迹聚类分析结果表明,东莞站点的污染气团主要来自于局地排放、东南海岸线以及华中地区的长距离输送,南海吹来的气流对其污染的贡献占比较小。
To study the pollution characteristics of black carbon(BC)aerosol in a typical city in the Pearl River Delta,BC data obtained from the Dongguan Meteorological Bureau site from December 31,2009 to December 31,2010-including frequency distribution characteristics,diurnal variations,and pollution sources-were analyzed.The results showed that(1)the frequency distribution of the BC concentration in the Dongguan site followed a lognormal distribution.The annual average concentration of BC was(3.98±3.42)μg/m^3 with a background concentration of(1.14±1.04)μg/m^3.The BC concentration was low in the wet season and high in the dry season.The BC level was lower than that in most mega cities in China but higher than those in the background stations and western cities.(2)The diurnal variation in the BC concentration showed two peaks during the morning and evening rush hours but was low in the afternoon.The diurnal pattern of BC was affected by the variability in meteorological conditions and traffic activities.(3)The frequency distribution of the absorptionÅngström exponent in the 370-950 nm range(AAE370-950)during the observation period was normally distributed,with an average annual value of 1.02.AAE370-950,and was relatively low in the wet season and high in the dry season.(4)The BC concentration was found to be negatively correlated with wind speed,thereby indicating that the wind had a dilution effect on BC.(5)The results of the backward trajectory clustering analysis showed that the polluted air masses in the Dongguan site mainly originated from local discharge,long-range transport,the southeast coastline,and central China.The air masses from the South China Sea were relatively clean.
作者
孙天林
吴兑
吴晟
孙嘉胤
陈慧忠
邓涛
李梅
周振
SUN Tian-lin;WU Dui;WU Cheng;SUN Jia-yin;CHEN Hui-zhong;DENG Tao;LI Mei;ZHOU Zhen(Institute of Mass Spectrometer and Atmospheric Environment,Jinan University,Guangzhou 510632,China;Guangdong Provincial Engineering Research Center for on-line source apportionment system of air pollution,Guangzhou 510632,China;Institute of Tropical and Marine Meteorology,China Meteorological Administration,Guangzhou 510080,China;Dongguan Meteorological Service,Dongguan 523000,China)
出处
《地球化学》
CAS
CSCD
北大核心
2020年第3期287-297,共11页
Geochimica
基金
国家自然科学基金(41605002,41475004)。
关键词
黑碳气溶胶
污染特征
波长吸收指数
来源分析
东莞市
black carbon aerosol
pollution characteristics
absorptionÅngström exponent
source analysis
Dongguan City
