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| Titel |
Simultaneous stable isotope analysis of methane and nitrous oxide on ice core samples |
| VerfasserIn |
C. J. Sapart, C. Veen, I. Vigano, M. Brass, R. S. W. Wal, M. Bock, H. Fischer, T. Sowers, C. Buizert, P. Sperlich, T. Blunier, M. Behrens, J. Schmitt, B. Seth, T. Röckmann |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 4, no. 12 ; Nr. 4, no. 12 (2011-12-02), S.2607-2618 |
| Datensatznummer |
250002143
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| Publikation (Nr.) |
 copernicus.org/amt-4-2607-2011.pdf |
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| Zusammenfassung |
Methane and nitrous oxide are important greenhouse gases which show a strong
increase in atmospheric mixing ratios since pre-industrial time as well as
large variations during past climate changes. The understanding of their
biogeochemical cycles can be improved using stable isotope analysis.
However, high-precision isotope measurements on air trapped in ice cores are
challenging because of the high susceptibility to contamination and
fractionation.
Here, we present a dry extraction system for combined CH4 and N2O
stable isotope analysis from ice core air, using an ice grating device. The
system allows simultaneous analysis of δD(CH4) or δ13C(CH4),
together with δ15N(N2O), δ18O(N2O)
and δ15N(NO+ fragment) on a single ice
core sample, using two isotope mass spectrometry systems. The optimum
quantity of ice for analysis is about 600 g with typical "Holocene" mixing
ratios for CH4 and N2O. In this case, the reproducibility
(1σ ) is 2.1‰ for δD(CH4), 0.18‰ for δ13C(CH4),
0.51‰ for δ15N(N2O), 0.69‰ for
δ18O(N2O) and 1.12‰ for δ15N(NO+ fragment).
For smaller amounts of ice the standard deviation increases,
particularly for N2O isotopologues. For both gases, small-scale
intercalibrations using air and/or ice samples have been carried out in
collaboration with other institutes that are currently involved in isotope
measurements of ice core air. Significant differences are shown between the
calibration scales, but those offsets are consistent and can therefore be
corrected for. |
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