Probing Mechanisms of New Particle Formation and Growth: A Combined Experimental, Theoretical and Modeling Approach

将进行一系列的实验室和模拟研究，以研究大气中新粒子的形成和生长过程。这项研究将通过改善空气质量和气候模型造福社会。实验室研究将集中在甲磺酸（MSA）与胺在水存在下的反应，这是一种已被证明非常有效地形成新颗粒的机制。一旦颗粒形成，尽管存在过量的水蒸气和MSA或胺，但它们的生长受到限制，这表明种子核在空气中的生长需要吸收其他有机物质。本研究选择了具有代表性的不同结构和官能团的有机物作为实验对象，主要目的是：（1）从气相酸、胺、水蒸气和一系列代表性的大气有机物的反应中，阐明NPFG的基本机理和动力学;和（2）开发这些过程的参数化，准确地描述NPFG在复杂的混合物，是适合用于大气模式。通过该项目开发的NPFG参数化将被纳入区域空气质量模型，并用于评估新颗粒形成对区域尺度的影响。

A series of laboratory and modeling studies will be conducted to study the process of new particle formation and growth (NPFG) in the atmosphere. This research will benefit society through improved air quality and climate modeling.Laboratory studies will focus on the reactions of methanesulfonic (MSA) acid with amines in the presence of water, a mechanism that has been shown to form new particles very efficiently. Once particles form, their growth is limited despite the presence of excess water vapor and either MSA or amine, suggesting that the growth of the seed nuclei in air requires the uptake of other organic species. Organic compounds with different structures and functional groups that are representative of atmospheric species have been carefully selected for the experiments.The project objectives are: (1) to elucidate the fundamental mechanisms and kinetics of NPFG from the reactions of gas phase acids, amines, water vapor, and a suite of representative atmospheric organic compounds; and (2) to develop a parameterization of these processes that accurately describes NPFG in complex mixtures that is appropriate for use in atmospheric models. The NPFG parameterization developed through this project will be incorporated into a regional air quality model and used to assess the impacts of new particle formation on a regional scale.