Collaborative Research: Formation of Organic Nitrogen and Secondary Organic Aerosol Related to Nitrate Radical Oxidation of Volatile Organic Compounds

这个项目的重点是增进对人类产生的排放如何与森林的生物源排放结合起来影响大气中小颗粒形成的了解。将在两种不同类型的森林（城市和偏远）部署一个流动实验室，以便比较和对比氮物种向森林的远距离和短程运输的影响。研究结果将有助于改进控制战略，最大限度地减少人为排放对健康、能见度和气候的影响。这项科学运动的主要目标是：(1)在美国中部沿南北样带的两个森林地点，在树冠上和树冠下，描述环境气溶胶、辐射和微量气体的特征；(2)使用原子比率（如氧碳比，O:C）量化SOA中的氧化水平，并确定颗粒有机硝酸盐（PON）的存在对观察到的亚微米颗粒物（PM）氧化状态的影响；(3)研究冠层内梯度和冠层间转运对亚微米PM、PON和氧化剂的影响；(4)确定氮氧化物（NOx）对各场所挥发性有机碳（VOC）氧化和SOA形成的影响；(5)比较和对比偏远地区、公路地区和城市森林地区的化学成分；(6)利用正矩阵分解（PMF）识别在树冠上和树冠下不同程度人为影响下的SOA的重要组成部分，确定对SOA有贡献的因素；(7)调查各地点氮氧化物的去向。

This project focuses on increasing the understanding of how human-produced emissions combine with biogenic emissions from forests to influence the formation of small particles in the atmosphere. A mobile laboratory will be deployed to two different types of forests (urban and remote) in order to compare and contrast the impact of long-range and short-range transport of nitrogen species to forests. The results will lead to improved control strategies that minimize the health, visibility and climate effects of anthropogenic emissions.The primary objectives of the science campaign are to: (1) Characterize the ambient aerosol, radiation, and trace gases at two forest sites, both above and below the canopy, and along a north-south transect in the central United States; (2) Quantify the level of oxidation found in SOA using atomic ratios (such as the oxygen to carbon ratio, O:C) and determine the impact the presence of particulate organic nitrate (PON) has on the observed oxidation state of the submicron particulate matter (PM); (3) Investigate how in-canopy gradients and through-canopy transport impact submicron PM, PON, and oxidants; (4) Determine the impact nitrogen oxides (NOx) have on volatile organic carbon (VOC) oxidation and SOA formation in all locations; (5) Compare and contrast the chemistry of remote, on-road, and urban forested areas; (6) Identify the factors contributing to SOA using positive matrix factorization (PMF) to identify important components of SOA under different levels of anthropogenic influence both above and below canopy; and (7) Investigate the fate of NOx in all locations.