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| Titel |
Contribution of very short-lived organic substances to stratospheric chlorine and bromine in the tropics – a case study |
| VerfasserIn |
J. C. Laube, A. Engel, H. Bönisch, T. Möbius, D. R. Worton, W. T. Sturges, K. Grunow, U. Schmidt |
| 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. 23 ; Nr. 8, no. 23 (2008-12-11), S.7325-7334 |
| Datensatznummer |
250006500
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| Publikation (Nr.) |
 copernicus.org/acp-8-7325-2008.pdf |
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| Zusammenfassung |
| The total stratospheric organic chlorine and bromine burden was derived from
balloon-borne measurements in the tropics (Teresina, Brazil, 5°04´ S,
42°52´ W) in 2005. Whole air samples were collected cryogenically at
altitudes between 15 and 34 km. For the first time, we report
measurements of a set of 28 chlorinated and brominated substances in the
tropical upper troposphere and stratosphere including ten substances with an
atmospheric lifetime of less than half a year. The substances were
quantified using pre-concentration techniques followed by Gas Chromatography
with Mass Spectrometric detection. In the tropical tropopause layer at
altitudes between 15 and 17 km we found 1.1–1.4% of the chlorine and
6–8% of the bromine to be present in the form of very short-lived
organic compounds. By combining the data with tropospheric reference data
and age of air observations the abundances of inorganic chlorine and bromine
(Cly and Bry) were derived. At an altitude of 34 km we calculated
3062 ppt of Cly and 17.5 ppt of Bry from the decomposition of both
long- and short-lived organic source gases. Furthermore we present
indications for the presence of additional organic brominated substances in
the tropical upper troposphere and stratosphere. |
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