Isotopic data of atmospheric methane from EDML and Vostok ice cores over a full glacial cycle, supplement to: Möller, Lars; Sowers, Todd A; Bock, Michael; Spahni, Renato; Behrens, Melanie K; Schmitt, Jochen; Miller, Heinz; Fischer, Hubertus (2013): Independent variations of CH4 emissions and isotopic composition over the past 160,000 years. Nature Geoscience, 6, 885-890

DOI

The response of natural CH4 sources to climate changes will be an important factor to consider as concentrations of this potent greenhouse gas continue to increase. Polar ice cores provide the means to assess this sensitivity in the past and have shown a close connection between CH4 levels and northern hemisphere temperature variability over the last glacial cycle. However, the contribution of the various CH4 sources and sinks to these changes is still a matter of debate. Contemporaneous stable CH4 isotope records in ice cores provide additional boundary conditions for assessing changes in the CH4 sources and sinks. Here we present new ice core CH4 isotope data covering the last 160,000 years, showing a clear decoupling between CH4 loading and carbon isotopic variations over most of the record. We suggest that d13CH4 variations were not dominated by a change in the source mix but rather by climate- and CO2-related ecosystem control on the isotopic composition of the methane precursor material, especially in seasonally inundated wetlands in the tropics. In contrast, relatively stable d13CH4 intervals occurred during large CH4 loading changes concurrently with past climate changes implying that most CH4 sources (most notably tropical wetlands) responded simultaneously.

Identifier
DOI https://doi.org/10.1594/PANGAEA.812116
Related Identifier https://doi.org/10.1038/ngeo1922
Metadata Access https://ws.pangaea.de/oai/provider?verb=GetRecord&metadataPrefix=datacite4&identifier=oai:pangaea.de:doi:10.1594/PANGAEA.812116
Provenance
Creator Möller, Lars; Sowers, Todd A; Bock, Michael; Spahni, Renato; Behrens, Melanie K; Schmitt, Jochen; Miller, Heinz; Fischer, Hubertus
Publisher PANGAEA - Data Publisher for Earth & Environmental Science
Publication Year 2013
Funding Reference Fifth Framework Programme; Fourth Framework Programme
Rights Creative Commons Attribution 3.0 Unported
OpenAccess true
Representation
Language English
Resource Type Supplementary Collection of Datasets
Format application/zip
Size 5 datasets
Discipline Earth System Research
Spatial Coverage (0.068W, -78.464S, 123.350E, -75.002N)
Temporal Coverage Begin 1980-01-01T00:00:00Z
Temporal Coverage End 2006-01-17T00:00:00Z