Reconciling Atmospheric OH Reactivity Measurements with PTR-ToF-MS Observations and Photochemical Box Model Simulations

臭氧和颗粒物是影响环境和人类健康的空气污染的组成部分;然而，目前对这些组成部分如何形成的理解仍然存在差距。在本项目中，进行了实验室实验，以揭示大气前体分子的反应。将结果与现有模型和现场数据进行比较，并将提供新的机制见解，有助于为空气污染控制策略提供信息。参与的研究生被纳入外展计划，以吸引K-12学生和教师。对活性挥发性有机化合物（VOCs）和氧化中间体和产物进行了系统的实验室研究，以提高目前对对流层光化学的理解。用于实验的串联室反应器系统配备了最先进的分析工具，包括高分辨率质子转移反应-质谱（PTR-ToF-MS）和比较反应性方法（CRM），分别用于分析组分和量化OH反应性。方法开发和仪器校准是这项工作的一个组成部分。新的观察与现有的箱模型进行评估，并与以前获得的现场数据集进行重新检查。结果可能揭示基本的新机制，并有助于更深入地了解各种污染水平下的臭氧和颗粒物产生。通过该项目支持PI和不同的研究生，并计划推广到小学生和教师，而中学生将有机会参观校园，体验动手空气采样和气体分析仪器。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Ozone and particulate matter are components of air pollution that affect the environment and human health; however, gaps remain in current understanding of how these components are formed. In the present project, laboratory experiments are conducted to shed light on reactions of atmospheric precursor molecules. Results are compared to existing models and field data and will provide new mechanistic insight that can help inform air pollution control strategies. Participating graduate students are integrated in the outreach plan to engage K-12 students and teaches. Systematic laboratory studies are performed on reactive volatile organic compounds (VOCs) and oxidation intermediates and products to improve current understanding of tropospheric photochemistry. The tandem chamber reactor system used for experiments is equipped with state-of-the-art analytical tools including high-resolution proton transfer reaction-mass spectrometry (PTR-ToF-MS) and comparative reactivity method (CRM) for analysis of components and to quantify OH reactivity, respectively. Method development and instrument calibration are an integral part of this work. New observations are evaluated with existing box models and compared to previously obtained field datasets for re-examination. Results may reveal fundamental new mechanisms and help gain greater insight into ozone and particulate matter production under various pollution levels. PIs and diverse graduate students are supported through this project, and outreach is planned to elementary school students and teachers, while middle school students will be provided opportunities to visit campus and experience hands-on air sampling and gas analyses instrumentation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.