Evolution in Secondary Organic Aerosol Formation in Urban Atmosphere

本项目的重点是研究导致城市大气中二次有机气溶胶（SOA）形成的大气化学过程。该研究将讨论导致SOA形成的关键前体或气体及其来源和波动范围。所开发的信息将有助于预测导致空气污染的城市SOA演变和设计有效的缓解战略。将要解决的科学问题是：(1)城市空气中最重要的SOA前体是什么？(2)最重要的SOA前身的来源是什么？(3)最重要的前体的SOA形成途径是什么？(4)在过去十年中，SOA的化学反应发生了变化吗？(5)化学运输模型中对城市SOA的描述是否可以改进？2022年夏季将在洛杉矶地区开展为期6周的实地活动。将这些数据与之前的研究（包括2010年CalNex的研究）进行比较，将显示SOA的前体和化学反应在过去十年中是如何演变的。该项目包括对几名研究生和本科生的培训。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project is focused on an investigation of the atmospheric chemistry processes that lead to the formation of secondary organic aerosol (SOA) in the urban atmosphere. The research will address the key precursors or gases that lead to the formation of SOA and their sources and volatility ranges. The information developed will help to predict the evolution of urban SOA that leads to air pollution and the design of effective mitigation strategies.The science questions that will be addressed are: (1) What are the most important SOA precursors in urban air? (2) What are the sources of the most important SOA precursors? (3) What are the SOA formation pathways for the most important precursors? (4) Has SOA chemistry changed over the past decade? and (5) Can the description of urban SOA in chemistry-transport models be improved?A 6-week field campaign will be conducted in the Los Angeles area in Summer 2022. Comparison of the data with previous studies, including the CalNex study in 2010, will show how the SOA precursors and chemistry have evolved over the last decade. The project includes training for several graduate and 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.