Daytime atmospheric chemistry of key compounds provoked by nighttime atmospheric chemistry (DARK KNIGHT).

生物来源和人为来源向大气排放大量挥发性有机化合物(VOCs，每年1300 TGC)。VOCs在释放到大气中后，在半挥发性化合物的作用下，与OH、NO3自由基和臭氧氧化，进入颗粒相，形成二次有机质量。尽管生物和人为的SOA对大气非常重要(每年910和9.7Tg)，但在形成机制和涉及的化合物方面仍存在差距。这部分是由迄今未知的形成机制造成的，也是由于导致SOA减少(如蒸发过程)和丢失数据集(NO3自由基反应)的机制造成的。在第一个项目阶段，由于昼夜化学的相互联系，已经成功地为人为的SOA化合物确定了一种新的SOA形成机制。在目前的提案中，将研究和描述SOA的蒸发，因为现有的数据集清楚地表明蒸发对夜间α-蒎烯SOA起着重要的作用。主要的蒸发产物和潜在的机理将被描述。本提案的第二个方面是生物和人为VOCs的NO3自由基反应的数据集。在第一个项目阶段，发现了现有数据的差距以及现有数据集的差异。将对这些差异的原因进行调查，并将生成最重要的生物和人为VOCs的NO3自由基反应的数据集。

Sources of biogenic and anthropogenic origin emit significant amounts of volatile organic compounds (VOCs, 1300 TgC per year) into the atmosphere. After release into the atmosphere, VOCs undergo oxidation with OH and NO3 radical and O3 under formation of semi-volatile compounds that partition into the particle phase leading to the formation of secondary organic mass. Although biogenic and anthropogenic SOA is of great importance for the atmosphere (910 and 9.7 Tg per year), gaps regarding the formation mechanisms and involved compounds still exist. This is partly caused by so-far unknown formation mechanism and also due to mechanisms that lead to a reduction of SOA (like evaporation processes) and missing data sets (NO3 radical reaction). Within the first project phase, a new SOA formation mechanism has been successfully identified for anthropogenic SOA compounds due to the interconnection of day- and night time chemistry. For the present proposal, the evaporation of SOA will be examined and characterized as the existing data set clearly shows that evaporation plays an important role for nocturnal alpha-pinene SOA. Main evaporation products and the underlying mechanisms will be characterized. A second aspect for the present proposal is the data set for NO3 radical reactions of biogenic and anthropogenic VOCs. Within the first project phase, gaps in available data as well as discrepancies in existing data sets were found. The identification of the reason for these discrepancies will be investigated and a data set for the NO3 radical reaction of the most important biogenic and anthropogenic VOCs will be generated.