气候变化领域集成服务门户(CCPortal): Kinetic modeling of formation and evaporation of secondary organic aerosol from NO3 oxidation of pure and mixed monoterpenes

CCPortal

DOI	10.5194/acp-20-15513-2020
	Kinetic modeling of formation and evaporation of secondary organic aerosol from NO3 oxidation of pure and mixed monoterpenes
	Berkemeier T.; Takeuchi M.; Eris G.; Ng N.L.
发表日期	2020
ISSN	1680-7316
起始页码	15513
结束页码	15535
卷号	20 期号:24
英文摘要	Organic aerosol constitutes a major fraction of the global aerosol burden and is predominantly formed as secondary organic aerosol (SOA). Environmental chambers have been used extensively to study aerosol formation and evolution under controlled conditions similar to the atmosphere, but quantitative prediction of the outcome of these experiments is generally not achieved, which signifies our lack in understanding of these results and limits their portability to large-scale models. In general, kinetic models employing state-of-the-art explicit chemical mechanisms fail to describe the mass concentration and composition of SOA obtained from chamber experiments. Specifically, chemical reactions including the nitrate radical (NO3) are a source of major uncertainty for assessing the chemical and physical properties of oxidation products. Here, we introduce a kinetic model that treats gas-phase chemistry, gas particle partitioning, particle-phase oligomerization, and chamber vapor wall loss and use it to describe the oxidation of the monoterpenes a-pinene and limonene with NO3. The model can reproduce aerosol mass and nitration degrees in experiments using either pure precursors or their mixtures and infers volatility distributions of products, branching ratios of reactive intermediates and particle-phase reaction rates. The gas-phase chemistry in the model is based on the Master Chemical Mechanism (MCM) but trades speciation of single compounds for the overall ability of quantitatively describing SOA formation by using a lumped chemical mechanism. The complex branching into a multitude of individual products in MCM is replaced in this model with product volatility distributions and detailed peroxy (RO2) and alkoxy (RO) radical chemistry as well as amended by a particlephase oligomerization scheme. The kinetic parameters obtained in this study are constrained by a set of SOA formation and evaporation experiments conducted in the Georgia Tech Environmental Chamber (GTEC) facility. For both precursors, we present volatility distributions of nitrated and non-nitrated reaction products that are obtained by fitting the kinetic model systematically to the experimental data using a global optimization method, the Monte Carlo genetic algorithm (MCGA). The results presented here provide new mechanistic insight into the processes leading to formation and evaporation of SOA. Most notably, the model suggests that the observed slow evaporation of SOA could be due to reversible oligomerization reactions in the particle phase. However, the observed non-linear behavior of precursor mixtures points towards a complex interplay of reversible oligomerization and kinetic limitations of mass transport in the particle phase, which is explored in a model sensitivity study. The methodologies described in this work provide a basis for quantitative analysis of multi-source data from environmental chamber experiments but also show that a large data pool is needed to fully resolve uncertainties in model parameters. © 2020 Author(s).
英文关键词	aerosol; chemical reaction; concentration (composition); evaporation; monoterpene; Monte Carlo analysis; nitrate; organic matter; oxidation; reaction kinetics
语种	英语
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/168886
作者单位	School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, United States; Multiphase Chemistry Department, Max Planck Institute for Chemistry, Mainz, Germany; School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA, United States; School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, United States
推荐引用方式 GB/T 7714	Berkemeier T.,Takeuchi M.,Eris G.,et al. Kinetic modeling of formation and evaporation of secondary organic aerosol from NO3 oxidation of pure and mixed monoterpenes[J],2020,20(24).
APA	Berkemeier T.,Takeuchi M.,Eris G.,&Ng N.L..(2020).Kinetic modeling of formation and evaporation of secondary organic aerosol from NO3 oxidation of pure and mixed monoterpenes.Atmospheric Chemistry and Physics,20(24).
MLA	Berkemeier T.,et al."Kinetic modeling of formation and evaporation of secondary organic aerosol from NO3 oxidation of pure and mixed monoterpenes".Atmospheric Chemistry and Physics 20.24(2020).