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| Titel |
Consistent simulation of bromine chemistry from the marine boundary layer to the stratosphere – Part 2: Bromocarbons |
| VerfasserIn |
A. Kerkweg, P. Jöckel, N. Warwick, S. Gebhardt, C. A. M. Brenninkmeijer, J. Lelieveld  |
| 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 ; 8, no. 19 ; Nr. 8, no. 19 (2008-10-15), S.5919-5939 |
| Datensatznummer |
250006406
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| Publikation (Nr.) |
 copernicus.org/acp-8-5919-2008.pdf |
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| Zusammenfassung |
| In this second part of a series of articles dedicated to a detailed analysis
of bromine chemistry in the atmosphere we address one (out of two) dominant
natural sources of reactive bromine. The two main source categories are the
release of bromine from sea salt and the decomposition of bromocarbons by
photolysis and reaction with OH. Here, we focus on
C1-bromocarbons. We show that the atmospheric chemistry general
circulation model ECHAM5/MESSy realistically simulates their emission,
transport and decomposition from the boundary layer up to the mesosphere. We
included oceanic emission fluxes of the short-lived bromocarbons
CH2Br2, CH2ClBr, CHClBr2, CHCl2Br,
CHBr3 and of CH3Br. The vertical profiles and the surface
mixing ratios of the bromocarbons are in general agreement with the (few
available) observations, especially in view of the limited information
available and the consequent coarseness of the emission fields. For
CHBr3, CHCl2Br and CHClBr2 photolysis is the most
important degradation process in the troposphere. In contrast to this,
tropospheric CH2Br2, CH3Br and CH2ClBr are more
efficiently decomposed by reaction with OH. In the free troposphere
approximately 40% of the C1-bromocarbons decompose by reaction with
OH. Our results indicate that bromoform contributes substantial
amounts of reactive bromine to the lower stratosphere and thus should not be
neglected in stratospheric simulations. |
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