Modeling the Multiday Evolution and Aging of Secondary Organic Aerosol During MILAGRO 2006
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- 作者：Katja Dzepina ; Christopher D. Cappa ; Rainer M. Volkamer ; Sasha Madronich ; Peter F. DeCarlo ; Rahul A. Zaveri ; Jose L. Jimenez
- 刊名：Environmental Science & Technology
- 出版年：2011
- 出版时间：April 15, 2011
- 年：2011
- 卷：45
- 期：8
- 页码：3496-3503
- 全文大小：1183K
- 年卷期：v.45,no.8(April 15, 2011)
- ISSN：1520-5851
文摘
In this study, we apply several recently proposed models to the evolution of secondary organic aerosols (SOA) and organic gases advected from downtown Mexico City at an altitude of 3.5 km during three days of aging, in a way that is directly comparable to simulations in regional and global models. We constrain the model with and compare its results to available observations. The model SOA formed from oxidation of volatile organic compounds (V-SOA) when using a non-aging SOA parameterization cannot explain the observed SOA concentrations in aged pollution, despite the increasing importance of the low-NOx channel. However, when using an aging SOA parameterization, V-SOA alone is similar to the regional aircraft observations, highlighting the wide diversity in current V-SOA formulations. When the SOA formed from oxidation of semivolatile and intermediate volatility organic vapors (SI-SOA) is computed following Robinson et al. (2007) the model matches the observed SOA mass, but its O/C is 2脳 too low. With the parameterization of Grieshop et al. (2009), the total SOA mass is 2脳 too high, but O/C and volatility are closer to the observations. Heating or dilution cause the evaporation of a substantial fraction of the model SOA; this fraction is reduced by aging although differently for heating vs dilution. Lifting of the airmass to the free-troposphere during dry convection substantially increases SOA by condensation of semivolatile vapors; this effect is reduced by aging.