The Fate of Acyl Peroxy Nitrates During Long-Range Pollution Transport and Atmosphere-Forest Interactions

该项目将集中于对一类重要的有机氮氧化物储存库--酰基过氧硝酸盐进行灵敏、高时间分辨率的现场观测。氮氧化物影响臭氧的丰度，臭氧是一种污染物，一种温室气体，也是大气氧化的调节器。在这项工作中，将在布洛吉特森林部署定制的化学电离质谱仪，作为内华达山脉西部黄松林合作实地活动的一部分，以测量特定酰基过氧基硝酸盐的混合比例和通量。活性氮的丰度和分配改变了有机氧化途径，影响了二次有机气溶胶的生长。大气中氮的沉积会影响生态系统中的碳储存，从而影响生态系统对二氧化碳水平上升的反应。酰基过氧硝酸盐沉积可能是一个重要的生态系统氮源。最近在一个自由对流层山地观测站(Mt.还将对这些氮氧化物储存库进行分析，以评估从亚洲输送到美国西北部的污染羽流中这些氮氧化物储存库的重要性。首要目标是详细了解酰基过氧基硝酸盐在各种环境中的去向，以及地方和区域过程对其全球丰度的影响。这项研究的更广泛的科学影响将是提高预测未来空气质量和气候变化的能力，氮氧化物的化学在其中发挥着基础性的作用。博士生和本科生将接受与现场部署最先进的质谱仪和解释结果数据有关的一系列分析技术和科学分析方面的培训。

This project will focus on making and interpreting sensitive, high time resolution, in situ observations of acyl peroxy nitrates, an important class of organic nitrogen oxide reservoirs. Nitrogen oxides affect the abundance of ozone, which is a pollutant, a greenhouse gas, and a regulator of atmospheric oxidation. In this work, a custom-built chemical ionization mass spectrometer will be deployed in Blodgett Forest as part of a collaborative field campaign in a western Sierra Nevada ponderosa pine forest, to measure mixing ratios and fluxes of specific acyl peroxy nitrates. The abundance and partitioning of reactive nitrogen alters organic oxidation pathways and impacts secondary organic aerosol growth. The deposition of atmospheric nitrogen affects carbon storage in ecosystems, and therefore their response to increasing CO2 levels. Acyl peroxy nitrate deposition may represent an important ecosystem nitrogen source. Observations recently obtained with this instrument at a free tropospheric mountain observatory (Mt. Bachelor, Oregon) will also be analyzed to assess the importance of these nitrogen oxide reservoirs in pollution plumes transported from Asia to the northwestern United States. The overriding goal is to develop a detailed understanding of the fate of acyl peroxy nitrates in a range of environments and of the influence of local and regional processes on their global abundance. The broader scientific impact of this research will be an improved ability to predict future changes in air quality and climate, in which the chemistry of nitrogen oxides plays a fundamental role. Doctoral and undergraduate students will be trained in a range of analytical techniques and scientific analyses related to the field deployment of a state-of-the-art mass spectrometer and interpretation of the resulting data.