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| Titel |
Modeling SOA formation from the oxidation of intermediate volatility n-alkanes |
| VerfasserIn |
B. Aumont, R. Valorso, C. Mouchel-Vallon, M. Camredon, J. Lee-Taylor, S. Madronich |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 16 ; Nr. 12, no. 16 (2012-08-21), S.7577-7589 |
| Datensatznummer |
250011404
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| Publikation (Nr.) |
 copernicus.org/acp-12-7577-2012.pdf |
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| Zusammenfassung |
| The chemical mechanism leading to SOA formation and ageing is expected
to be a multigenerational process, i.e. a successive formation of
organic compounds with higher oxidation degree and lower vapor
pressure. This process is here investigated with the explicit
oxidation model GECKO-A (Generator of Explicit Chemistry and Kinetics
of Organics in the Atmosphere). Gas phase oxidation schemes are
generated for the C8–C24 series of
n-alkanes. Simulations are conducted to explore the time evolution
of organic compounds and the behavior of secondary organic aerosol
(SOA) formation for various preexisting organic aerosol concentration
(COA). As expected, simulation results show that (i) SOA
yield increases with the carbon chain length of the parent
hydrocarbon, (ii) SOA yield decreases with decreasing COA,
(iii) SOA production rates increase with increasing COA
and (iv) the number of oxidation steps (i.e. generations) needed to
describe SOA formation and evolution grows when COA
decreases. The simulated oxidative trajectories are examined in a two
dimensional space defined by the mean carbon oxidation state and the
volatility. Most SOA contributors are not oxidized enough to be
categorized as highly oxygenated organic aerosols (OOA) but reduced
enough to be categorized as hydrocarbon like organic aerosols (HOA),
suggesting that OOA may underestimate SOA. Results show that the model
is unable to produce highly oxygenated aerosols (OOA) with large
yields. The limitations of the model are discussed. |
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