Aqueous Aerosol Chemistry: Elucidating the Mechanisms Causing Mismatch between Field and Laboratory Chemical Composition of Biomass Burning Organic Aerosol

该项目将调查生物质燃烧的排放以及由此产生的导致大气中二次有机气溶胶形成的化学机制和过程。将进行新的实验室模拟，并将结果与最近几次实地活动的数据进行比较，这些活动测量了野火的排放，以确定在实验室和野外物种有机气溶胶之间观察到的差距。在这个项目中，PIS计划：(1)在不同湿度和氧化条件下对选定的酚类化合物进行实验室氧化实验，并获得所产生的SOA的样品；(2)分析实验室样品以提供半挥发性有机物种的分子水平形态；(3)阐明和量化反映孤立的生物质燃烧相关的SOA形成机制和过程(气体、颗粒或水相、光解)的新示踪剂，并将这些示踪剂与环境观测联系起来，用于模型开发；以及(4)更新开放获取的加州大学伯克利分校戈尔茨坦有机生物和环境光谱图书馆(UCB-Globes)数据库，提供社区使用的观察到的化合物。这些模拟旨在弥合实验室和现场观察到的有机气溶胶之间的差距。该项目包括对一名博士后学者和几名本科生的支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This project will investigate emissions from biomass burning and the resulting chemical mechanisms and processes that lead to the formation of secondary organic aerosol (SOA) in the atmosphere. New laboratory simulations will be performed, and the results will be compared with data from several recent field campaigns that measured emissions from wildfires to identify the gaps that have been observed between laboratory and field speciated organic aerosol. This effort is expected to broaden the knowledge of primary and secondary chemicals in the atmosphere from biomass burning and enable improvements in modeling their effects on air quality and climate.In this project, the PIs plan to: (1) conduct laboratory oxidation experiments of selected phenolic compounds under varying humidity and oxidizing conditions and obtain samples of the resulting SOA; (2) analyze the laboratory samples to provide molecular-level speciation of semi-volatile organic species; (3) elucidate and quantify novel tracers reflective of isolated biomass-burning related SOA formation mechanisms and processes (gas, particle, or aqueous phases, photolysis) and connect these with ambient observations for use in model development; and (4) update the open-access University of California, Berkeley, Goldstein Library of Organic Biogenic and Environmental Spectra (UCB-GLOBES) database with observed compounds for community use. The simulations are designed to bridge the gap observed between laboratory and field speciated organic aerosol.The project includes support for a postdoctoral scholar and several undergraduate students.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.