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Titel |
Evaluation of the atmospheric significance of multiphase reactions in atmospheric secondary organic aerosol formation |
VerfasserIn |
A. Gelencsér, Varga |
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 ; 5, no. 10 ; Nr. 5, no. 10 (2005-10-28), S.2823-2831 |
Datensatznummer |
250003112
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Publikation (Nr.) |
copernicus.org/acp-5-2823-2005.pdf |
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Zusammenfassung |
In a simple conceptual cloud-aerosol model the mass of secondary organic
aerosol (SOA) that may be formed in multiphase reaction in an idealized
scenario involving two cloud cycles separated with a cloud-free period is
evaluated. The conditions are set to those typical of continental clouds,
and each parameter used in the model calculations is selected as a mean of
available observational data of individual species for which the multiphase
SOA formation route has been established. In the idealized setting gas and
aqueous-phase reactions are both considered, but only the latter is expected
to yield products of sufficiently low volatility to be retained by aerosol
particles after the cloud dissipates. The key variable of the model is the
Henry-constant which primarily determines how important multiphase reactions
are relative to gas-phase photooxidation processes. The precursor considered
in the model is assumed to already have some affinity to water, i.e. it is a
compound having oxygen-containing functional group(s). As a principal model
output an aerosol yield parameter is calculated for the multiphase SOA
formation route as a function of the Henry-constant, and has been found to
be significant already above H~103 M atm-1. Among the
potential precursors that may be eligible for this mechanism based on their
Henry constants, there are a suite of oxygenated compounds such as primary
oxidation products of biogenic and anthropogenic hydrocarbons, including,
for example, pinonaldehyde. Finally, the analogy of multiphase SOA formation
to in-cloud sulfate production is exploited. |
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