Characteristics of aerosol pollution during heavy haze events in Suzhou, China
Characteristics of aerosol pollution during heavy haze events in Suzhou, China
复制标题
苏州重霾天气气溶胶污染特征
DOI：
10.5194/acp-16-7357-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
He, Kebin
中科院分区：
文献类型：
--
作者：
Tian, Mi;Wang, Huanbo;He, Kebin
2013年1月，中国多个城市特别是东部地区发生了特大霾天气事件。在上海以东的江苏省中等城市苏州，通过在线监测系统进行了包括PM及其主要化学成分(水溶性无机离子、有机碳(OC)和元素碳(EC))和相关气相前体的小时浓度的全面测量。PM(空气动力学直径为2.5 微米或以下的颗粒物)在雾霾天经常超过150 微克 ，最高值在2013年1月14日达到324 微克 。不利的天气条件(高相对湿度、低降雨量、低风速和低气压)有利于灰霾的形成。在前两次灰霾过程中，观测到较高浓度的二次气溶胶物种(包括SO、NO、NH和SOC)和气体前体，而在第三次灰霾过程中，初级碳质物种的排放量增加，这表明灰霾的形成机制不同。有机物(OM)、氨氮(NHSO)和氨氮(NHNO)是造成能见度损害的主要因素。高浓度的硫酸盐和硝酸盐在低相对湿度条件下可以用均相气相反应来解释，而在相对高相对湿度条件下可以用非均相过程来解释。气团轨迹聚类和潜在源贡献函数分析表明，研究区气溶胶污染主要是由局地活动和周边城市输送的源造成的。
Extremely severe haze weather events occurred in many cities in China, especially in the east part of the country, in January 2013. Comprehensive measurements including hourly concentrations of PMand its major chemical components (water-soluble inorganic ions, organic carbon (OC), and elemental carbon (EC)) and related gas-phase precursors were conducted via an online monitoring system in Suzhou, a medium-sized city in Jiangsu province, just east of Shanghai. PM(particulate matter with an aerodynamic diameter of 2.5 µm or less) frequently exceeded 150 µg mon hazy days, with the maximum reaching 324 µg mon 14 January 2013. Unfavorable weather conditions (high relative humidity (RH), and low rainfall, wind speed, and atmospheric pressure) were conducive to haze formation. High concentrations of secondary aerosol species (including SO, NO, NH, and SOC) and gaseous precursors were observed during the first two haze events, while elevated primary carbonaceous species emissions were found during the third haze period, pointing to different haze formation mechanisms. Organic matter (OM), (NHSO, and NHNOwere found to be the major contributors to visibility impairment. High concentrations of sulfate and nitrate might be explained by homogeneous gas-phase reactions under low RH conditions and by heterogeneous processes under relatively high RH conditions. Analysis of air mass trajectory clustering and potential source contribution function showed that aerosol pollution in the studied areas was mainly caused by local activities and surrounding sources transported from nearby cities.