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| Titel |
Modeling organic aerosol from the oxidation of α-pinene in a Potential Aerosol Mass (PAM) chamber |
| VerfasserIn |
S. Chen, W. H. Brune, A. T. Lambe, P. Davidovits, T. B. Onasch |
| 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 ; 13, no. 9 ; Nr. 13, no. 9 (2013-05-15), S.5017-5031 |
| Datensatznummer |
250018654
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| Publikation (Nr.) |
 copernicus.org/acp-13-5017-2013.pdf |
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| Zusammenfassung |
| A model has been developed to simulate the formation and evolution of
secondary organic aerosol (SOA) and was tested against data produced in a
Potential Aerosol Mass (PAM) flow reactor and a large environmental chamber.
The model framework is based on the two-dimensional volatility basis set
approach (2D-VBS), in which SOA oxidation products in the model are
distributed on the 2-D space of effective saturation concentration
(Ci*) and oxygen-to-carbon ratio (O : C). The modeled organic
aerosol mass concentrations (COA) and O : C agree with laboratory
measurements within estimated uncertainties. However, while both measured
and modeled O : C increase with increasing OH exposure as expected, the
increase of modeled O : C is rapid at low OH exposure and then slows as OH
exposure increases while the increase of measured O : C is initially slow and
then accelerates as OH exposure increases. A global sensitivity analysis
indicates that modeled COA values are most sensitive to the assumed
values for the number of Ci* bins, the heterogeneous OH
reaction rate coefficient, and the yield of first-generation products.
Modeled SOA O : C values are most sensitive to the assumed O : C of
first-generation oxidation products, the number of
Ci* bins, the heterogeneous OH reaction rate coefficient, and
the number of O : C bins. All these sensitivities vary as a function of OH
exposure. The sensitivity analysis indicates that the 2D-VBS model framework
may require modifications to resolve discrepancies between modeled and
measured O : C as a function of OH exposure. |
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