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| Titel |
The stable isotopic composition of atmospheric molecular hydrogen at the Cabauw tall tower in the Netherlands |
| VerfasserIn |
A. M. Batenburg, M. E. Popa, A. T. Vermeulen, W. C. M. van den Bulk, P. A. C. Jongejan, T. Röckmann |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250062256
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| Zusammenfassung |
| Molecular hydrogen (H2) is a promising energy carrier that might replace fossil fuels in
vehicles. It has great potential for making transportation more sustainable, but there may be
environmental side effects that, to some degree, offset the benefits. Concerns have
been raised that large-scale leakage of H2 into the atmosphere could affect the
atmosphere’s oxidative capacity and stratospheric ozone chemistry. To assess these risks, a
better understanding of the global, regional and global atmospheric H2 cycle is
needed. Since the H2 source and sink processes have large effects on δD(H2), due to
the large relative mass difference between ‘ordinary’ hydrogen and deuterium,
studying the stable isotopic composition of H2 (δD(H2)) is a promising way to
achieve this. Over the last decade, studies of the isotope effects in H2 source and
sink processes have appeared, δD(H2) has been incorporated into global chemical
transport models and many more environmental observations of δD(H2) have been
published. The latter, however, were mostly obtained from samples that were collected at
ground level at remote locations, which is not sufficient to fully characterize the H2
cycle or to assess the possible environmental effects of H2 leakage in very polluted
regions.
For this project, samples are collected at the Cabauw tall tower owned by KNMI. The
Cabauw tower is 213 m tall and located in a central part of the Netherlands. It is equipped
with a tubing system with air inlets at 20, 60, 120, and 200 meter altitude. This tubing system
was used to make continuous measurements of carbon monoxide (CO) and H2 mixing ratios,
but also to collect flasks samples at different heights for the analysis of δD(H2). More than
200 samples were collected over a period of more than three years. The results
show that the local H2 cycle at Cabauw is under heavy anthropogenic influence
compared to Mace Head, a station that receives mostly clean marine background air at
the Irish West Coast. On average, m(H2) is larger and δD(H2) lower at Cabauw, a
result of anthropogenic emissions of deuterium-depleted H2. Because of the same
anthropogenic emissions, the samples collected from the lower levels of the tower
tend to have larger m(H2) and lower δD(H2) than the samples collected from the
higher levels. This also indicates that the local uptake of H2 by soils is relatively
weak. |
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