Interlaboratory comparison of [delta]13C and [delta]D measurements of atmospheric CH4 for combined use of data sets from different laboratories

• Verfasst von: Umezawa, Taku [VerfasserIn]
• Verfasst von: Veidt, Cordelia [VerfasserIn]
• Verfasst von: Levin, Ingeborg [VerfasserIn]
• Titel: Interlaboratory comparison of [delta]13C and [delta]D measurements of atmospheric CH4 for combined use of data sets from different laboratories
• Verf.angabe: Taku Umezawa, Carl Brenninkmeijer, Thomas Röckmann, Carina Veen, Stanley Tyler, Ryo Fujita, Shinji Morimoto, Shuji Aoki, Todd Sowers, Jochen Schmitt, Michael Bock, Jonas Beck, Hubertus Fischer, Sylvia Michel, Bruce Vaughn, John Miller, James White, Gordon Brailsford, Hinrich Schaefer, Peter Sperlich, Willi A. Brand, Michael Rothe, Thomas Blunier, David Lowry, Rebecca E. Fisher, Euan G. Nisbet, Andrew L. Rice, Peter Bergamaschi, Cordelia Veidt, and Ingeborg Levin
• E-Jahr: 2018
• Jahr: 2 March 2018
• Umfang: 25 S.
• Fussnoten: Gesehen am 20.02.2020 ; Im Titel ist "delta" jeweils als griechisches Symbol dargestellt ; Im Titel ist die Zahl "13" hochgestellt und die Zahl "4" tiefgestellt
• Titel Quelle: Enthalten in: Atmospheric measurement techniques
• Ort Quelle: Katlenburg-Lindau : Copernicus, 2008
• Jahr Quelle: 2018
• Band/Heft Quelle: 11(2018), Seite 1207-1231
• ISSN Quelle: 1867-8548
• DOI: doi:10.5194/amt-11-1207-2018
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1690481137

Abstract

We report results from a worldwide interlaboratory comparison of samples among laboratories that measure (or measured) stable carbon and hydrogen isotope ratios of atmospheric CH4 (δ¹³C-CH4 and δD-CH4). The offsets among the laboratories are larger than the measurement reproducibility of individual laboratories. To disentangle plausible measurement offsets, we evaluated and critically assessed a large number of intercomparison results, some of which have been documented previously in the literature. The results indicate significant offsets of δ¹³C-CH4 and δD-CH4 measurements among data sets reported from different laboratories; the differences among laboratories at modern atmospheric CH4 level spread over ranges of 0.5 ‰ for δ¹³C-CH4 and 13 ‰ for δD-CH4. The intercomparison results summarized in this study may be of help in future attempts to harmonize δ¹³C-CH4 and δD-CH4 data sets from different laboratories in order to jointly incorporate them into modelling studies. However, establishing a merged data set, which includes δ¹³C-CH4 and δD-CH4 data from multiple laboratories with desirable compatibility, is still challenging due to differences among laboratories in instrument settings, correction methods, traceability to reference materials and long-term data management. Further efforts are needed to identify causes of the interlaboratory measurement offsets and to decrease those to move towards the best use of available δ¹³C-CH4 and δD-CH4 data sets.