HOx Radical Chemistry in Forest Environments: Measurements and Characterization of Instrument Interferences

这项研究的重点是测量大气中几种最重要的化合物，羟基(OH)和过氧化氢(HO2)自由基。这些化合物在大气化学中很重要，因为它们控制着许多对气候变化问题至关重要的痕量气体的寿命，而且它们可以极大地影响空气质量。科学家们发现，通过各种方法对这些化合物的测量与预测其浓度的模型之间存在许多不一致。这项工作将调查这些分歧的性质，并专注于改进这些化合物的测量，从而提高模型更好地预测气候和空气质量的能力。尽管城市地区HOX(OH+HO2)浓度的测量和建模之间存在合理的一致性，但在以高混合比例的生物挥发性有机化合物为特征的森林环境中的测量结果与模拟结果显示出重大差异。这项研究包括LP/LIF-FAGE仪器的优化、实验室动力学实验、非正式仪器比对研究，以及在变化的环境条件下各种森林环境下仪器性能的调查。森林测量将在几个地点进行，包括布鲁明顿校区附近的印第安纳大学研究和教学保护区野外实验室，密歇根州北部的PROPHET(氧化剂研究计划：光化学、排放和运输)，以及附近的森林加速演替实验场。这项工作将支持几名研究生，特别是少数民族学生将被鼓励参与研究。

This research focuses on the measurement of several of the most important chemical compounds in the atmosphere, the hydroxyl (OH) and hydroperoxy (HO2) radicals. These compounds are important in atmospheric chemistry because they control the lifetimes of many trace gases important to issue of climate change and they can greatly influence air quality. Scientists have found many disagreements between the measurements of these compounds by a variety of methods and by the models that predict their concentrations. This work will investigate the nature of these disagreements and focus on improving the measurement of these compounds, thereby improving the ability of models to better predict climate and air quality.Although there has been reasonable agreement between measured and modeled HOx (OH + HO2) concentrations in urban areas, measurements in forested environments characterized by high mixing ratios of biogenic volatile organic compounds have shown major discrepancies with modeling results. This research includes optimization of the LP/LIF-FAGE instrument, laboratory kinetics experiments, informal instrument intercomparison studies, and investigations of instrument performance in a variety of forest environments under changing environmental conditions. The forest measurements will take place at several locations including the Indiana University Research and Teaching Preserve field lab near the Bloomington campus, the PROPHET (Program for Research on Oxidants: PHotochemistry, Emissions and Transport) site in northern Michigan, as well as at the nearby Forest Accelerated Succession Experiment site. This work will support several graduate students and minority student will be especially encouraged to participate in the research.