Studies of the Fluxes of Atmospheric Organic Nitrogen Compounds to a Forest Environment

本项目研究中度污染森林环境中有机氮化合物的形成和命运。这些化合物可能在氮循环和大气二氧化碳的固存中起着关键作用——陆地生物圈和周围大气之间的相互作用了解甚少，目前研究森林生态系统碳固存的人尚未广泛考虑这一研究领域。具体而言，该项目将发展测量某些选定的烷基硝酸盐（异构体）硝酸异戊二烯和过氧酰基硝酸盐（包括过氧乙酰基硝酸盐）通量的能力，为硝酸异戊二烯的绝对校准制定标准，并通过在森林环境中沉积来描述有机硝酸盐的命运。该项目将在密歇根大学生物站的“氧化剂：光化学、排放和运输研究计划”（PROPHET）现场进行。有机硝酸盐与羟基自由基（OH）反应的动力学也将在实验室进行研究。关于更广泛的影响，该项目将描述一些可能重要的森林-大气相互作用，提供对陆地森林生态系统内氮循环在碳循环中的作用的见解，并改善目前对森林生物地球化学的了解。该项目将通过向一些年轻科学家（其中许多是女性）转让技术，以及通过机构和PROPHET项目的推广——通过更大的NSF综合研究生教育和研究培训（IGERT）和生物圈大气研究与培训（BART）项目——提供奖学金和能力建设，促进更广泛的社区教育和参与。

This project investigates the formation and fate of organic nitrogen compounds in a moderately polluted forest environment. Such compounds may play a crucial role in nitrogen cycling and sequestration of atmospheric carbon dioxide - interactions between the terrestrial biosphere and the ambient atmosphere are understood poorly and present an area of study not widely considered at this time by those concerned with carbon sequestration in forest ecosystems. Specifically, the project will develop the capacity for measuring fluxes of some selected alkyl nitrates - (isomeric) isoprene nitrate(s) and peroxyacyl nitrates including peroxyacetyl nitrate (PAN), producing standard(s) for absolute calibration of isoprene nitrate, and characterizing the fate of organic nitrates through deposition within a forest environment. This project will be conducted at the Program for Research on Oxidants: Photochemistry, Emissions, and Transport (PROPHET) field site at the University of Michigan Biological Station. Kinetics of organic nitrate reactions with the hydoxyl radical (OH) will also be investigated in the laboratory. With regard to broader impacts, the project will characterize some potentially important forest-atmosphere interactions, offer insight into the role of nitrogen cycling in the carbon cycle within terrestrial forest ecosystems, and improve present understanding of forest biogeochemistry. The project will provide scholarship and capacity building through technology transfer to a number of young scientists, many of those women, and through institutional and PROPHET program outreach - through the larger NSF Integrative Graduate Education and Research Traineeship (IGERT) and Biosphere Atmosphere Research and Training (BART) programs - facilitate broader community education and involvement.