Highly time-resolved chemical characterization of atmospheric fine particles during 2010 Shanghai World Expo
Highly time-resolved chemical characterization of atmospheric fine particles during 2010 Shanghai World Expo
复制标题
2010 年上海世博会期间大气细颗粒物的高度时间分辨化学表征
DOI：
10.5194/acp-12-4897-2012
复制
发表时间：
2012-01-01
影响因子：
6.3
通讯作者：
Zhu, T.
中科院分区：
文献类型：
--
作者：
Huang, X. -F.;He, L. -Y.;Zhu, T.
抽象的。上海拥有2000多万人口，是中国最大的特大城市。在过去的几十年里，工业和大城市排放量的迅速增加使空气质量恶化，细颗粒物污染是主要问题之一。然而，在上海，采用先进的测量技术对大气细颗粒物进行系统表征的工作非常缺乏。在2010年上海世博会期间，我们在上海市区部署了一台高分辨率飞行时间气溶胶质谱仪（HR-ToF-AMS）和一台单粒子烟尘光度计（SP2），以测量高时间分辨率的细颗粒物。4分钟分辨率的PM 1质量浓度范围为5.5至155 μg m−3，平均值为29.2 μg m−3。平均而言，硫酸盐和有机物（OM）是PM 1中含量最高的组分，分别占总质量的33.3%和28.7%，而硝酸盐的含量随着PM 1负荷的增加呈增加趋势，表明上海市高细颗粒物污染的光化学性质.利用HR-ToF-AMS和SP2，发现OM的平均OM/OC比（有机质质量/有机碳质量）为1.55，黑碳（BC）的平均内部混合BC的数量分数为41.2%。高分辨率有机质谱数据集的正矩阵分解（PMF）分析确定了烃类（HOA），半挥发性含氧（SV-OOA）和低挥发性含氧（LV-OOA）有机气溶胶组分，平均分别占总有机质量的24.0%，46.8%和29.2%。其日变化模式具有明显的时间延迟，可能是由HOA（和/或其同时排放的气态有机污染物）到SV-OOA再到LV-OOA的光化学氧化过程。后向轨迹分析表明，西北大陆气团代表最严重的污染物区域输送条件与最高的硝酸盐和SV-OOA分数。此外，在上海的结果进行了比较，最近在世界其他特大城市进行的类似测量。
Abstract. Shanghai, with a population of over 20 million, is the largest mega-city in China. Rapidly increasing industrial and metropolitan emissions have deteriorated its air quality in the past decades, with fine particle pollution as one of the major issues. However, systematic characterization of atmospheric fine particles with advanced measurement techniques has been very scarce in Shanghai. During 2010 Shanghai World Expo, we deployed a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a single particle soot photometer (SP2) in urban Shanghai between 15 May and 10 June 2010 to measure fine particles with a high time resolution. The 4-min resolution PM1 mass concentration ranged from 5.5 to 155 μg m−3, with an average of 29.2 μg m−3. On average, sulfate and organic matter (OM) were the most abundant PM1 components, accounting for 33.3 and 28.7% of the total mass, respectively, while the fraction of nitrate showed an increasing trend with the increasing PM1 loading, indicating the photochemical nature of high fine particle pollution in Shanghai. Taking advantage of HR-ToF-AMS and SP2, OM was found to have an average OM/OC ratio (organic matter mass/organic carbon mass) of 1.55 and black carbon (BC) had an average number fraction of internally mixed BC of 41.2%. Positive matrix factorization (PMF) analysis on the high resolution organic mass spectral dataset identified a hydrocarbon-like (HOA), a semi-volatile oxygenated (SV-OOA), and a low-volatility oxygenated (LV-OOA) organic aerosol component, which on average accounted for 24.0, 46.8, and 29.2% of the total organic mass, respectively. The diurnal patterns of them with interesting time delay possibly implied a photochemical oxidizing process from HOA (and/or its concurrently emitted gaseous organic pollutants) to SV-OOA to LV-OOA. Back trajectory analysis indicated that the northwesterly continental air mass represented the most severe pollutant regional transport condition with the highest nitrate and SV-OOA fractions. In addition, the results in Shanghai were compared with similar measurements performed recently in other mega-cities in the world.