摘要
为了评估华南地区国庆期间频发的大范围区域光化学污染事件对华南背景大气的影响,2018年国庆节前后(9月19日~10月19日),在广东南岭国家大气背景站对光化学污染的代表产物过氧乙酰硝酸酯(PAN)开展了连续在线观测,并对PAN的浓度特征和来源进行了分析.结果表明,研究期间南岭PAN的平均体积浓度为(0.66±0.54)×10^(-9),最大值为2.33×10^(-9),显著高于国内外其他背景站点((0.21~0.44)×10^(-9)),且PAN的夜间浓度一直维持在较高的水平;PAN和O3(r=0.90)、NO_(2)(r=0.87)的相关性较强,通过PAN和O3的线性拟合估算出O3的大气背景体积浓度为(46.22±0.65)×10^(-9),表明南岭光化学反应十分活跃;受区域光化学污染事件的影响,国庆期间南岭PAN的浓度显著升高,达到(1.18±0.45)×10^(-9),而同期NO/NO_(2)比值降低,导致PAN大气寿命延长,有利于PAN的本地累积;结合气团后向轨迹,潜在源贡献分布以及前体物NO_(2)的全国分布特征分析,发现国庆期间高浓度PAN主要来自湖南,湖北、河南、江西等华中地区.
To evaluate the influence of the frequent large-scale regional photochemical pollution events on the background atmosphere in South China during the National Day holiday,continuous online observations of peroxyacetyl nitrate(PAN)a representative product of photochemical pollution,were conducted for the first time at Nanling National Atmospheric Background Monitoring Station in Guangdong,around the National Day of 2018(September 19th~October 19th).The concentration characteristics and sources of PAN were also analysed.The average volume concentration of PAN during the period was(0.66±0.54)×10^(-9),with the maximum value of 2.33×10^(-9),which was significantly higher than other background sites in China and abroad((0.21~0.44)×10^(-9)),and the concentration at night was constantly high.Additionally,PAN correlated well with O3(r=0.90)and NO_(2)(r=0.87),and the atmospheric background volume concentration of O3 was estimated to be(46.22±0.65)×10-9by a linear fitting method,indicating that the photochemical reaction at Nanling was active.As a result of the regional photochemical pollution events,the concentrations of PAN at Nanling site increased significantly during the National Day holiday,reaching(1.18±0.45)×10^(-9),while NO/NO_(2)ratio decreased during the same period,resulting in a prolonged atmospheric lifetime of PAN and contributing to local accumulation of PAN.Combining the backward trajectory of the air mass,the distribution of potential sources and the nationwide distribution characteristics of the precursor NO_(2),it was found that the high concentration of PAN during the National Day holiday at Nanling site mainly came from Hunan,Hubei,Henan,Jiangxi and other central regions of China.
作者
廖敏萍
龚道程
王少霞
刘涛
王好
邓硕
欧劼
郑昱
王伯光
LIAOMin-ping;GONG Dao-cheng;WANG Shao-xia;LIU Tao;WANG Hao;DENG Shuo;OU Jie;ZHENG Yu;WANG Bo-guang(Institute for Environmental and Climate Research,Jinan University,Guangzhou 511443,China;Chinese Society for Environmental Sciences,Beijing 100082,China;Guangdong Northern Regional Ecological Environment Monitoring Center and Guangdong Shaoguan Ecological Environmental Monitoring Center Station,Shaoguan 512026,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第6期2493-2503,共11页
China Environmental Science
基金
国家重点研发计划项目(2018YFC0213901)
国家自然科学基金资助面上项目(42077190,41877370)
广东省科技厅专项科学考察项目(2019B121202002)。
