Secondary organic aerosol formation from isoprene photooxidation during cloud condensation-evaporation cycles
Secondary organic aerosol formation from isoprene photooxidation during cloud condensation-evaporation cycles
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DOI：
10.5194/acp-16-1747-2016
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发表时间：
2016-01-01
影响因子：
6.3
通讯作者：
Doussin, J. -F.
中科院分区：
文献类型：
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作者：
Bregonzio-Rozier, L.;Giorio, C.;Doussin, J. -F.
通过大气模拟室中的异戊二烯/氮氧化物/光系统研究了云事件对异戊二烯二次有机气溶胶 (SOA) 形成的影响。结果表明，液态水云的存在会导致比干燥条件下更快、更高的 SOA 形成。当光氧化反应早期产生云时，在任何 SOA 形成之前，观察到 SOA 快速形成，质量产率范围为 0.002 至 0.004。这些产量比干燥条件下观察到的产量高 2 倍和 4 倍。当云在后期光氧化阶段产生时，在异戊二烯SOA稳定在其最大质量浓度后，观察到SOA质量浓度快速增加（2倍或更高）。 SOA 化学成分受云生成的影响：云事件期间形成的额外 SOA 由有机物和含硝酸盐的物质组成。这种 SOA 的形成可能与水溶性挥发性有机化合物 (VOC) 在水相中的溶解以及进一步的水相反应有关。本研究通过实验证明了云诱导的 SOA 形成，从而强调了水多相系统在大气 SOA 形成估计中的重要性。
The impact of cloud events on isoprene secondary organic aerosol (SOA) formation has been studied from an isoprene / NOx / light system in an atmospheric simulation chamber. It was shown that the presence of a liquid water cloud leads to a faster and higher SOA formation than under dry conditions. When a cloud is generated early in the photooxidation reaction, before any SOA formation has occurred, a fast SOA formation is observed with mass yields ranging from 0.002 to 0.004. These yields are 2 and 4 times higher than those observed under dry conditions. When the cloud is generated at a later photooxidation stage, after isoprene SOA is stabilized at its maximum mass concentration, a rapid increase (by a factor of 2 or higher) of the SOA mass concentration is observed. The SOA chemical composition is influenced by cloud generation: the additional SOA formed during cloud events is composed of both organics and nitrate containing species. This SOA formation can be linked to the dissolution of water soluble volatile organic compounds (VOCs) in the aqueous phase and to further aqueous phase reactions. Cloud-induced SOA formation is experimentally demonstrated in this study, thus highlighting the importance of aqueous multiphase systems in atmospheric SOA formation estimations.