Studies of Organic Nitrate Concentration, Composition, and Variation in the Troposphere

本研究项目涉及对流层中烷基硝酸盐和其他有机硝酸盐种类的研究。烷基硝酸盐是羟基自由基引发的碳氢化合物在氮氧化物存在下氧化的产物。其他有机硝酸盐是由烯烃、羰基和生物烃在氮氧化物存在下氧化形成的。由于它们对活性氮收支的潜在贡献，以及它们对对流层臭氧化学的重要性，因此需要详细的信息来了解全球对流层中有机硝酸盐的来源、组成、浓度和运输。本研究计划包括选定的有机硝酸盐化合物的实验室和实地调查。实验室研究将改进分析方法，并检查测试系统中碳氢化合物的反应。该实地项目旨在精确测量一套有机硝酸盐，这些有机硝酸盐在偏远地区受到含有初级和次级有机排放的气团的间歇性输入的影响。这些站点包括北极、北大西洋和美国大陆的一个站点。由于这些地点已经开展了活跃的大气化学研究，因此测量可以与广泛的大气化学过程有关。对硝酸盐（和其他种类）的浓度和组成的测量将与现有的有机硝酸盐形成、来源和运输模型进行比较。这些研究将有助于完善对全球大气中氮/碳转化和活性氮命运的理解。

This research project is concerned with the study of alkyl nitrates and other organic nitrate species in the troposphere. Alkyl nitrates are products of hydroxyl radical initiated hydrocarbon oxidation in the presence of the oxides of nitrogen. Other organic nitrates are formed from alkenes, carbonyls, and biogenic hydrocarbons when they are oxidized in the presence of nitrogen oxides. Because of their potential contribution to the reactive nitrogen budget, and because of their significance to tropospheric ozone chemistry, detailed information is required to understand the sources, composition, concentration, and transport of organic nitrates in the global troposphere. This research program includes laboratory and field investigations of selected organic nitrates compounds. Laboratory studies will improve analytical methodology and examine reactions of hydrocarbons in test systems. The field program is designed to accurately measure a suite of organic nitrates at remote sites subject to episodic inputs of air masses containing primary and secondary organic emissions. The sites include a station in the Arctic, in the North Atlantic, and in the continental US. Since these sites have active atmospheric chemistry studies already underway, the measurements can be related to a broad scope of atmospheric chemical processes. Measurements of the concentration and composition of nitrates (and other species) will be compared to existing models of organic nitrate formation, sources, and transport. These studies should help to refine understanding of nitrogen/carbon transformations and fate of reactive nitrogen in the global atmosphere.