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| Titel |
A comparison of the chemical sinks of atmospheric organics in the gas and aqueous phase |
| VerfasserIn |
S. A. Epstein, S. A. Nizkorodov |
| 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. 17 ; Nr. 12, no. 17 (2012-09-12), S.8205-8222 |
| Datensatznummer |
250011442
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| Publikation (Nr.) |
 copernicus.org/acp-12-8205-2012.pdf |
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| Zusammenfassung |
| Photochemical reactions represent the main pathway for the removal of
non-methane volatile organic compounds (VOCs) in the atmosphere. VOCs may
react with hydroxyl radical (OH), the most important atmospheric oxidant, or
they can be photolyzed by actinic radiation. In the presence of clouds and
fog, VOCs may partition into the aqueous phase where they can undergo
aqueous photolysis and/or reaction with dissolved OH. The significance of
direct aqueous photolysis is largely uncertain due to the lack of published
absorption cross sections and photolysis quantum yields. In light of this,
we strive to identify atmospherically relevant VOCs where removal by aqueous
photolysis may be a significant sink. The relative importance of different
photochemical sinks is assessed by calculating the ratios of the removal
rates inside air parcels containing cloud and fog droplets. This relative
approach provides useful information in spite of the limited aqueous
photolysis data. Results of this work should help guide researchers in
identifying molecules that are the most likely to undergo aqueous OH
oxidation and photolysis. For example, we find that out of the 27
atmospherically relevant species investigated, the removal of glyceraldehyde
and pyruvic acid by aqueous photolysis is potentially an important sink. We
also determine the relative magnitudes of these four chemical sinks for the
set of relevant organic compounds. |
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