The Role of Peroxy Radicals: Linking Gas-Phase Oxidation Chemistry to Secondary Organic Aerosol Formation

这项工作的重点是提高对大气中二次有机气溶胶（SOA -由气相化合物形成的非常小的颗粒）形成过程的基本理解。正在进行一系列的实验室实验，以评估导致SOA形成的各种化学物质的大气条件和浓度。 本研究的目的是：（1）通过实验研究不同过氧自由基反应途径对生物源和人为源碳氢化合物光化学氧化产生的SOA产率、气相和气溶胶组成的影响;（2）确定不同过氧自由基反应途径对气溶胶挥发性的影响。拟议的工作重点是氧化OH自由基在干燥条件下（相对湿度1%）。 硫酸铵被用作气溶胶生长的种子，过氧化氢（H2 O2）、亚硝酸（HONO）或亚硝酸甲酯（CH 3 ONO）被用作OH源。这项研究也将有助于提高氮氧化物如何影响SOA的形成过程的理解。该项目包括在哥伦比亚中学（一个标题1学校）的推广计划，与地球科学教师和中学生合作，以增加他们在科学，技术，工程和数学（STEM）学科的知识和经验。

This work focuses on improving the fundamental understanding of processes that contribute to the formation of secondary organic aerosol (SOA - very small particles formed from gas-phase compounds) in the atmosphere. A series of laboratory chamber experiments is being conducted to evaluate the atmospheric conditions and concentrations of various chemical species that lead to SOA formation. The results of this research will lead to improved models for predicting SOA formation.The objectives of this research are: (1) To experimentally map out the effects of the different reaction channels of peroxy radicals on SOA yields, gas- and aerosol-phase composition from photochemical oxidations of biogenic and anthropogenic hydrocarbons, and (2) To determine the effects of different peroxy radical reaction pathways on aerosol volatility. The proposed work focuses on oxidation by OH radicals under dry conditions (relative humidity 1%). Ammonium sulfate is being used as seeds for aerosol growth and hydrogen peroxide (H2O2), nitrous acid (HONO), or methyl nitrite (CH3ONO) is being used as the OH source. This research will also help improve understanding of how nitrogen oxides influence the SOA formation process.The project includes outreach plans at the Columbia Middle School (a Title 1 school) to work with an Earth Science teacher and middle school students to increase their knowledge and experience in science, technology, engineering, and math (STEM) disciplines.