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| Titel |
Heavy hydrogen in the stratosphere |
| VerfasserIn |
T. Röckmann, T. S. Rhee, A. Engel |
| 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 ; 3, no. 6 ; Nr. 3, no. 6 (2003-11-19), S.2015-2023 |
| Datensatznummer |
250001337
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| Publikation (Nr.) |
 copernicus.org/acp-3-2015-2003.pdf |
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| Zusammenfassung |
| We report measurements of the deuterium content of molecular hydrogen
(H2) obtained from a suite of air samples that were collected during a stratospheric balloon flight between 12 and
33 km at 40º N in October 2002. Strong deuterium enrichments of up to 400
permil versus Vienna Standard Mean Ocean Water (VSMOW) are observed, while the
H2 mixing ratio remains virtually constant. Thus, as hydrogen is processed through the
H2 reservoir in the stratosphere, deuterium is accumulated in H2
. Using box model calculations we investigated the effects of H2 sources and sinks on the stratospheric enrichments. Results show that considerable isotope
enrichments in the production of H2 from CH4 must take place, i.e., deuterium is transferred
preferentially to H2 during the CH4 oxidation sequence. This supports recent conclusions from
tropospheric H2 isotope measurements which show that H2 produced photochemically from
CH4 and non-methane hydrocarbons must be enriched in deuterium to balance the
tropospheric hydrogen isotope budget. In the absence of further data on isotope fractionations
in the individual reaction steps of the CH4 oxidation sequence, this effect cannot be
investigated further at present. Our measurements imply that molecular hydrogen has to be
taken into account when the hydrogen isotope budget in the stratosphere is investigated. |
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