Organic molecular compositions and temporal variations of summertime mountain aerosols over Mt. Tai, North China Plain
Organic molecular compositions and temporal variations of summertime mountain aerosols over Mt. Tai, North China Plain
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DOI：
10.1029/2008jd009900
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发表时间：
2008-10-08
影响因子：
4.4
通讯作者：
Wang, Zifa
中科院分区：
文献类型：
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作者：
Fu, Pingqing;Kawamura, Kimitaka;Wang, Zifa
总悬浮颗粒物（TSP）收集在山顶。泰（海拔1534米）白天和夜间的基础上，在夏季运动（2006年5月至6月），其特征在于有机分子组成，使用溶剂萃取/衍生化和气相色谱/质谱技术。正烷烃，脂肪酸，脂肪醇，糖，甘油和多酸，邻苯二甲酸酯被发现作为主要的有机化合物类，而木质素和树脂产品，甾醇，芳香酸，藿烷，多环芳烃（PAHs）被检测为次要类别。糖（白天49.8-2115 ng m（-3），平均640 ng m（-3）;夜间18.1-4348 ng m（-3），平均799 ng m（-3））是主要的化合物类别。左旋葡聚糖，一种特定的纤维素热解产物，被检测为最丰富的单一化合物，其次是C-28脂肪醇，邻苯二甲酸二异丁酯和二正丁酯，C-29正烷烃，C-16和C28脂肪酸，和苹果酸。通过基于其来源对有机化合物进行分组，我们发现陆地植物蜡的排放是TSP的最重要来源（30-34%），其次是生物质燃烧产物（25-27%）（例如，左旋葡聚糖、木质素和树脂产品）、由于农业活动导致的土壤再悬浮（15-18%）、二次氧化产物（8-10%）、塑料排放（3-10%）、海洋/微生物来源（6%）和使用化石燃料导致的城市/工业排放（4%）。然而，本研究中不包括光化学来源的低分子量二羧酸（如草酸）。苹果酸被发现是远远高于地面水平的报告，这表明在山区的自由对流层增强的光化学生产。生物质燃烧示踪剂的时间变化（例如，左旋葡聚糖、半乳聚糖、甘露聚糖）和一些高等植物蜡衍生化合物类别表明，在这次活动期间有两个主要（E1和E2）和一个次要（E3）生物质燃烧事件。大多数的化合物类显示出较高的浓度在夜间样品时，有机气溶胶可以从不同的来源地区的山顶长距离传输。在行星边界层（PBL）之上。研究还表明，天山上空的自由对流层是一个强对流层。在初夏收获季节，华北平原的农业废弃物（如小麦秸秆）的田间燃烧对太湖的影响很大。
Total suspended particles (TSP) were collected at the summit of Mt. Tai (1534 m above sea level) on a daytime and nighttime basis during a summertime campaign (May-June 2006) and were characterized for organic molecular compositions using solvent extraction/derivatization and gas chromatography/mass spectrometry technique. The n-Alkanes, fatty acids, fatty alcohols, sugars, glycerol and polyacids, and phthalate esters were found as major organic compound classes, whereas lignin and resin products, sterols, aromatic acids, hopanes, and polycyclic aromatic hydrocarbons (PAHs) were detected as minor classes. Sugars (49.8-2115 ng m(-3), average 640 ng m(-3) in daytime; 18.1-4348 ng m(-3), 799 ng m(-3) in nighttime) were found to be the dominant compound class. Levoglucosan, a specific cellulose pyrolysis product, was detected as the most abundant single compound, followed by C-28 fatty alcohol, diisobutyl and di-n-butyl phthalates, C-29 n-alkane, C-16 and C28 fatty acids, and malic acid. By grouping organic compounds based on their sources, we found that emission of terrestrial plant waxes was the most significant source (30-34%) of the TSP, followed by biomass burning products (25-27%) (e.g., levoglucosan and lignin and resin products), soil resuspension (15-18%) due to agricultural activities, secondary oxidation products (8-10%), plastic emission (3-10%), marine/microbial sources (6%), and urban/industrial emissions from fossil fuel use (4%). However, low molecular weight dicarboxylic acids (such as oxalic acid) of photochemical origin were not included in this study. Malic acid was found to be much higher than those reported in the ground level, suggesting an enhanced photochemical production in the free troposphere over mountain areas. Temporal variations of biomass burning tracers (e.g., levoglucosan, galactosan, mannosan) and some higher plant wax derived compound classes suggested that there were two major (E1 and E2) and one minor (E3) biomass-burning events during this campaign. Most of the compound classes showed higher concentrations in nighttime samples when organic aerosols can be long-range transported from different source regions to the summit of Mt. Tai above the planetary boundary layer (PBL). This study also demonstrates that the free troposphere over Mt. Tai is heavily influenced by field burning of agricultural wastes such as wheat straws in the North China Plain during the harvest season in early summer.