A Multiphase Study of the Nature, Sources, and Fate of Atmospheric Organic Nitrogen

该项目涉及大气中有机硝酸盐的来源、去向和重要性，以及生物源挥发性有机化合物(BVOCs)在森林环境中固定大气氮中的作用。这项研究在更广泛的背景下了解森林对二氧化碳的吸收，包括作为气候和大气氮变化的人为输入的未来变化，具有重要意义。该项目包括实地研究，目的是确定在气相和云水中形成有机硝酸盐的重要途径。实地研究将在密歇根大学生物站(UMBS)氧化剂研究计划：光化学、排放和运输(PROPHET)实验室进行。云水研究将利用大气研究实验室(ALAR)，这是普渡大学运营的一架小型仪表式飞机。该项目的主要目标是：(1)测量大气中有机硝酸盐的垂直分布，使用带有采样设备的系留气球，检查异戊二烯和其他BVOCs在隔离大气氮中的作用；(2)利用最新开发的质子转移反应线性离子陷阱(PTRLIT)，调查UMBS森林上空大气中非常活跃的生物挥发性有机化合物的作用；以及BVOCs形成大气有机硝酸盐的动力学和机制的实验室研究；(3)研究微生物处理云水氮的能力(使用云水收集器)，包括调查云水中轻的烷基硝酸盐的潜在产生；(4)实验室光化学反应器研究水相生产烷基硝酸盐，以提高我们预测大气氮的命运的能力。该项目将为本科生和研究生的发展和培训提供机会，并通过普渡气候变化研究中心(PCCRC)开展重要的外展和教育活动。具体地说，将创建一个关于人类活动、农业实践、大气氮和气候变化之间关系的展览。展览将包括对土地利用变化和气候之间关系的动手交互计算机模拟，并将被制作出来，目的是向全国各地的科学和技术博物馆展示。

This project addresses the sources, fate, and importance of atmospheric organic nitrates, and the role of biogenic volatile organic compounds (BVOCs) in sequestering atmospheric nitrogen in forest environments. This research is important in the broader context of understanding forest uptake of carbon dioxide, including future changes as climate and anthropogenic inputs of atmospheric nitrogen change. The project includes field studies aimed at identification of the important pathways for organic nitrate formation in both the gas phase, and in cloud water. The field studies will be conducted at the University of Michigan Biological Station (UMBS) Program for Research on Oxidants: Photochemistry, Emissions, and Transport (PROPHET) laboratory. The cloud water studies will make use of the Airborne Laboratory for Atmospheric Research (ALAR), a small, instrumented aircraft operated by Purdue University.The main objectives of the project are: (1) Measurements of the vertical profile of atmospheric organic nitrates, using a tethered balloon with sampling equipment to examine the role of isoprene and other BVOCs in sequestering atmospheric nitrogen; (2) Investigation of the role of very reactive biogenic volatile organic compounds in the atmosphere above the UMBS forest, using a newly developed Proton Transfer Reaction Linear Ion Trap (PTRLIT); also laboratory studies of the kinetics and mechanisms for the formation of atmospheric organic nitrates from BVOCs; (3) A study of the ability of microorganisms to process cloud water nitrogen (using a cloud water collector), including an investigation of the potential production of light alkyl nitrates in cloud water; (4) Laboratory photochemical reactor studies of aqueous phase production of alkyl nitrates to improve our ability to predict the fate of atmospheric nitrogen.The project will provide opportunities for undergraduate and graduate student development and training, and also involve significant outreach and education activities through the Purdue Climate Change Research Center (PCCRC). Specifically, an exhibit will be created about the relationships between human activities, agricultural practices, atmospheric nitrogen, and climate change. The exhibit will involve hands-on interactive computer simulations of the relationships between land use change and climate, and will be produced with the intention of making it available to science and technology museums around the country.