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| Titel |
The contribution of natural and anthropogenic very short-lived species to stratospheric bromine |
| VerfasserIn |
R. Hossaini, M. P. Chipperfield, W. Feng, T. J. Breider, E. Atlas, S. A. Montzka, B. R. Miller, F. Moore, J. Elkins |
| 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. 1 ; Nr. 12, no. 1 (2012-01-05), S.371-380 |
| Datensatznummer |
250010440
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| Publikation (Nr.) |
 copernicus.org/acp-12-371-2012.pdf |
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| Zusammenfassung |
We have used a global three-dimensional chemical transport model to quantify
the impact of the very short-lived substances (VSLS) CHBr3, CH2Br2,
CHBr2Cl, CHBrCl2, CH2BrCl and C2H5-Br on the bromine budget of
the stratosphere. Atmospheric observations of these gases allow constraints
on surface mixing ratios that, when incorporated into our model, contribute
~4.9–5.2 parts per trillion (ppt) of inorganic bromine (Bry)
to the stratosphere. Of this total, ~76 % comes from naturally-emitted
CHBr3 and CH2Br2. The remaining species individually contribute
modest amounts. However, their accumulated total accounts for up to
~1.2 ppt of the supply and thus should not be ignored. We have compared
modelled tropical profiles of a range of VSLS with observations from the
recent 2009 NSF HIPPO-1 aircraft campaign. Modelled profiles agree reasonably
well with observations from the surface to the lower tropical tropopause
layer.
We have also considered the poorly studied anthropogenic VSLS, C2H5Br,
CH2BrCH2Br, n-C3H7Br
and i-C3H7Br. We find the local
atmospheric lifetime of these species in the tropical tropopause layer are
~183, 603, 39 and 49 days, respectively. These species, particularly
C2H5Br and CH2BrCH2Br, would thus be important carriers of
bromine to the stratosphere if emissions were to increase substantially. Our
model shows ~70–73 % and ~80–85 % of bromine from these
species in the tropical boundary layer can reach the lower stratosphere. |
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