Simultaneous stable isotope analysis of methane and nitrous oxide on ice core samples

C. J. Sapart, C. Van Der Veen, I. Vigano, M. Brass, R. S.W. Van De Wal, M. Bock, H. Fischer, T. Sowers, C. Buizert, P. Sperlich, T. Blunier, M. Behrens, J. Schmitt, B. Seth, T. Röckmann

Research output: Contribution to journalArticle

29 Scopus citations

Abstract

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 δ 15N(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(CH 4), 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.

Original languageEnglish (US)
Pages (from-to)2607-2618
Number of pages12
JournalAtmospheric Measurement Techniques
Volume4
Issue number12
DOIs
StatePublished - Dec 1 2011

All Science Journal Classification (ASJC) codes

  • Atmospheric Science

Fingerprint Dive into the research topics of 'Simultaneous stable isotope analysis of methane and nitrous oxide on ice core samples'. Together they form a unique fingerprint.

  • Cite this

    Sapart, C. J., Van Der Veen, C., Vigano, I., Brass, M., Van De Wal, R. S. W., Bock, M., Fischer, H., Sowers, T., Buizert, C., Sperlich, P., Blunier, T., Behrens, M., Schmitt, J., Seth, B., & Röckmann, T. (2011). Simultaneous stable isotope analysis of methane and nitrous oxide on ice core samples. Atmospheric Measurement Techniques, 4(12), 2607-2618. https://doi.org/10.5194/amt-4-2607-2011