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

Details

• Journal Title:
  Atmospheric Measurement Techniques
• Personal Author:
  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 ; Brand, Willi A. ; Rothe, Michael ; Blunier, Thomas ; Lowry, David ; Fisher, Rebecca E. ; Nisbet, Euan G. ; Rice, Andrew L. ; Bergamaschi, Peter ; Veidt, Cordelia ; Levin, Ingeborg
• NOAA Program & Office:
  CIRES (Cooperative Institute for Research in Environmental Sciences)
• Description:
  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.
• Keywords:
  Atmospheric Chemistry Data Sets Atmospheric Chemistry Data Sets
• Source:
  Atmos. Meas. Tech., 11, 1207–1231, 2018
• DOI:
  https://doi.org/10.5194/amt-11-1207-2018
• Document Type:
  Journal Article
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:b72dcb90c6941a84436409bc06af0fd8f3d8af8c169b8ef1aeecf4974bc4df969344143c362241b26ca9e3c1e3563baaa10f6feb27fdb4748517bad7cc050f14
• Download URL:
  https://repository.library.noaa.gov/view/noaa/27030/noaa_27030_DS1.pdf
• File Type:
  [PDF - 969.56 KB ]