Interlaboratory comparison of δ¹³C and δD measurements of atmospheric CH₄ for combined use of data sets from different laboratories

Umezawa, Taku; Brenninkmeijer, Carl A. M.; Röckmann, Thomas; van der Veen, Carina; Tyler, Stanley C.; Fujita, Ryo; Morimoto, Shinji; Aoki, Shuji; Sowers, Todd; Schmitt, Jochen; Bock, Michael; Beck, Jonas; Fischer, Hubertus; Michel, Sylvia E.; Vaughn, Bruce H.; Miller, John B.; White, James W. C.; Brailsford, Gordon; Schaefer, Hinrich; Sperlich, Peter; ... (2018). Interlaboratory comparison of δ¹³C and δD measurements of atmospheric CH₄ for combined use of data sets from different laboratories. Atmospheric Measurement Techniques (AMT), 11(2), pp. 1207-1231. Copernicus Publications 10.5194/amt-11-1207-2018

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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.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Climate and Environmental Physics
08 Faculty of Science > Physics Institute
10 Strategic Research Centers > Oeschger Centre for Climate Change Research (OCCR)

UniBE Contributor:

Schmitt, Jochen; Bock, Michael; Beck, Jonas and Fischer, Hubertus

Subjects:

500 Science > 530 Physics
500 Science > 520 Astronomy
600 Technology > 620 Engineering

ISSN:

1867-1381

Publisher:

Copernicus Publications

Language:

English

Submitter:

Monika Wälti-Stampfli

Date Deposited:

07 May 2018 15:22

Last Modified:

07 May 2018 15:22

Publisher DOI:

10.5194/amt-11-1207-2018

BORIS DOI:

10.7892/boris.113922

URI:

https://boris.unibe.ch/id/eprint/113922

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