Secondary organic aerosol formation from photooxidation of naphthalene and alkylnaphthalenes: implications for oxidation of intermediate volatility organic compounds (IVOCs)
Item
Title (Dublin Core)
Secondary organic aerosol formation from photooxidation of naphthalene and alkylnaphthalenes: implications for oxidation of intermediate volatility organic compounds (IVOCs)
Description (Dublin Core)
Current atmospheric models do not include secondary organic aerosol (SOA) production from gas-phase reactions of polycyclic aromatic hydrocarbons (PAHs). Recent studies have shown that primary emissions undergo oxidation in the gas phase, leading to SOA formation. This opens the possibility that low-volatility gas-phase precursors are a potentially large source of SOA. In this work, SOA formation from gas-phase photooxidation of naphthalene, 1-methylnaphthalene (1-MN), 2-methylnaphthalene (2-MN), and 1,2-dimethylnaphthalene (1,2-DMN) is studied in the Caltech dual 28-m<sup>3</sup> chambers. Under high-NO<sub>x</sub> conditions and aerosol mass loadings between 10 and 40 μg m<sup>−3</sup>, the SOA yields (mass of SOA per mass of hydrocarbon reacted) ranged from 0.19 to 0.30 for naphthalene, 0.19 to 0.39 for 1-MN, 0.26 to 0.45 for 2-MN, and constant at 0.31 for 1,2-DMN. Under low-NO<sub>x</sub> conditions, the SOA yields were measured to be 0.73, 0.68, and 0.58, for naphthalene, 1-MN, and 2-MN, respectively. The SOA was observed to be semivolatile under high-NO<sub>x</sub> conditions and essentially nonvolatile under low-NO<sub>x</sub> conditions, owing to the higher fraction of ring-retaining products formed under low-NO<sub>x</sub> conditions. When applying these measured yields to estimate SOA formation from primary emissions of diesel engines and wood burning, PAHs are estimated to yield 3–5 times more SOA than light aromatic compounds over photooxidation timescales of less than 12 h. PAHs can also account for up to 54% of the total SOA from oxidation of diesel emissions, representing a potentially large source of urban SOA.
Creator (Dublin Core)
Chan, A. W. H.
Kautzman, K. E.
Chhabra, P. S.
Surratt, J. D.
Chan, M. N.
Crounse, J. D.
Kürten, A.
Wennberg, P. O.
Flagan, R. C.
Seinfeld, J. H.
Date (Dublin Core)
2018-01-15
Type (Dublin Core)
Text
Format (Dublin Core)
application/pdf
Identifier (Dublin Core)
10.5194/acp-9-3049-2009
https://acp.copernicus.org/articles/9/3049/2009/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
