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| Titel |
The overwhelming role of soils in the global atmospheric hydrogen cycle |
| VerfasserIn |
T. S. Rhee, C. A. M. Brenninkmeijer, T. Röckmann |
| 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 ; 6, no. 6 ; Nr. 6, no. 6 (2006-05-19), S.1611-1625 |
| Datensatznummer |
250003826
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| Publikation (Nr.) |
 copernicus.org/acp-6-1611-2006.pdf |
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| Zusammenfassung |
| The removal of molecular hydrogen (H2) from the atmosphere is dominated
by the uptake in soils. Notwithstanding, estimates of the magnitude of this
important process on a global scale are highly uncertain. The CARIBIC
aircraft observations of the seasonal variations of H2 and its D/H
isotopic ratio in the Northern Hemisphere allow an independent, better
constrained estimate. We derive that 82% of the annual turnover of
tropospheric H2 is due to soil uptake, equaling 88 (±11)Tg a-1,
of which the Northern Hemisphere alone accounts for 62 (±10)Tg a-1.
Our calculations further show that tropospheric H2
has a lifetime of only 1.4 (±0.2) years – significantly shorter than
the recent estimate of ~2 years – which is expected to decrease in the
future. In addition, our independent top-down approach, confined by the
global and hemispheric sinks of H2, indicates 64 (±12)Tg a-1
emissions from various sources of volatile organic compounds by
photochemical oxidation in the atmosphere. This estimate is as much as up to
60% larger than the previous estimates. This large airborne production
of H2 helps to explain the fairly homogeneous distribution of H2
in the troposphere. |
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