Record Details
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
| Names |
Chappellaz, J.
(creator) Stowasser, C. (creator) Blunier, T. (creator) Baslev-Clausen, D. (creator) Brook, Edward J. (creator) Dallmayr, R. (creator) Fain, X. (creator) Lee, J. E. (creator) Mitchell, L. E. (creator) Pascual, O. (creator) Romanini, D. (creator) Rosen, J. (creator) Schuepbach, S. (creator) |
| Date Issued | 2013 (iso8601) |
| Note | This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Copernicus Publications on behalf of the European Geosciences Union. The published article can be found at: http://www.clim-past.net/volumes_and_issues.html. |
| Abstract | The Greenland NEEM (North Greenland Eemian Ice Drilling) operation in 2010 provided the first opportunity to combine trace-gas measurements by laser spectroscopic instruments and continuous-flow analysis along a freshly drilled ice core in a field-based setting. We present the resulting atmospheric methane (CH₄) record covering the time period from 107.7 to 9.5 ka b2k (thousand years before 2000 AD). Companion discrete CH₄ measurements are required to transfer the laser spectroscopic data from a relative to an absolute scale. However, even on a relative scale, the high-resolution CH₄ data set significantly improves our knowledge of past atmospheric methane concentration changes. New significant sub-millennial-scale features appear during interstadials and stadials, generally associated with similar changes in water isotopic ratios of the ice, a proxy for local temperature. In addition to the midpoint of Dansgaard–Oeschger (D/O) CH₄ transitions usually used for cross-dating, sharp definition of the start and end of these events brings precise depth markers (with ±20 cm uncertainty) for further cross-dating with other palaeo- or ice core records, e.g. speleothems. The method also provides an estimate of CH₄ rates of change. The onsets of D/O events in the methane signal show a more rapid rate of change than their endings. The rate of CH₄ increase associated with the onsets of D/O events progressively declines from 1.7 to 0.6 ppbv yr⁻¹ in the course of marine isotope stage 3. The largest observed rate of increase takes place at the onset of D/O event #21 and reaches 2.5 ppbv yr⁻¹. |
| Genre | Article |
| Access Condition | http://creativecommons.org/licenses/by/3.0/us/ |
| Identifier | Chappellaz, J., Stowasser, C., Blunier, T., Baslev-Clausen, D., Brook, E. J., Dallmayr, R., Faïn, X., Lee, J. E., Mitchell, L. E., Pascual, O., Romanini, D., Rosen, J., and Schüpbach, S.: High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core, Climate of the Past, 9, 2579-2593, doi:10.5194/cp-9-2579-2013, 2013. |
