Chemical Coupling of Halogens and Oxygenated VOC (Volatile Organic Compounds): Observations, Experiments and Modeling

该项目包括实地观测、实验室实验和建模任务，旨在调查大气中与卤素（如溴和碘）相关的化学物质。将在两个山顶观测站（南半球热带印度洋的Maido和北半球热带太平洋的Mauna Loa）进行测量，以评估卤素浓度的季节性变化。这项研究将为评估对流层卤素在多大程度上改变对流层臭氧（一种强效温室气体）的寿命提供关键的新信息，并作为形成影响大气甲烷寿命的羟基自由基的前体。因此，这些结果将与模拟未来气候变化直接相关。将进行实验室实验，研究溴自由基与海洋空气中脂肪酸形成的不饱和含氧挥发性有机化合物（OVOC）的反应机理，以及乙二醛和脂肪醛的产率潜力。建模工作将把现场测量结果与全球模型的结果进行比较，以评估OVOC的BrOx汇对对流层臭氧、甲烷和大气汞的卤素影响。

This project includes field observations, laboratory experiments, and modeling tasks designed to investigate the chemistry associated with halogens, such as bromine and iodine, in the atmosphere. Measurements will be made at two mountain top observatories (Maido in the Southern Hemisphere tropical Indian Ocean and Mauna Loa in the Northern Hemisphere tropical Pacific Ocean) to assess the seasonal variability of halogen concentrations. This research will provide critical new information for assessing the extent to which tropospheric halogens modify the lifetime of tropospheric ozone, a potent greenhouse gas, and serve as a precursor for the formation of hydroxyl radicals, that influence the lifetime of atmospheric methane. Thus the results will be directly relevant for modeling future climate change.Laboratory experiments will be conducted to investigate the reaction mechanism of bromine radicals with unsaturated oxygenated volatile organic compounds (OVOC) that can form from aliphatic acids in marine air and the potential for product yields of glyoxal and aliphatic aldehydes. Modeling efforts will compare field measurements with the results of global models to assess the impacts of the BrOx sink from OVOC for halogen impacts on tropospheric ozone, methane, and atmospheric mercury.