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Titel |
Emission ratio and isotopic signatures of molecular hydrogen emissions from tropical biomass burning |
VerfasserIn |
F. A. Haumann, A. M. Batenburg, G. Pieterse, C. Gerbig, M. C. Krol, 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 ; 13, no. 18 ; Nr. 13, no. 18 (2013-09-24), S.9401-9413 |
Datensatznummer |
250085707
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Publikation (Nr.) |
copernicus.org/acp-13-9401-2013.pdf |
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Zusammenfassung |
In this study, we identify a biomass-burning signal in molecular hydrogen
(H2) over the Amazonian tropical rainforest. To quantify this signal,
we measure the mixing ratios of H2 and several other species as well
as the H2 isotopic composition in air samples that were collected in
the BARCA (Balanço Atmosférico Regional de Carbono na Amazônia)
aircraft campaign during the dry season. We derive a relative H2
emission ratio with respect to carbon monoxide (CO) of
0.31 ± 0.04 ppb ppb−1 and an isotopic source signature of −280 ± 41‰
in the air masses influenced by tropical biomass burning. In order to
retrieve a clear source signal that is not influenced by the soil uptake of
H2, we exclude samples from the atmospheric boundary layer. This
procedure is supported by data from a global chemistry transport model. The
ΔH2 / ΔCO emission ratio is significantly lower
than some earlier estimates for the tropical rainforest. In addition, our
results confirm the lower values of the previously conflicting estimates of
the H2 isotopic source signature from biomass burning. These values
for the emission ratio and isotopic source signatures of H2 from
tropical biomass burning can be used in future bottom-up and top-down
approaches aiming to constrain the strength of the biomass-burning source for
H2. Hitherto, these two quantities relied only on combustion
experiments or on statistical relations, since no direct signal had been
obtained from in-situ observations. |
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