High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core
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...
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ftoregonstate:ir.library.oregonstate.edu:g158bn68g 2024-09-15T18:09:36+00:00 High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core Chappellaz, J. Stowasser, C. Blunier, T. Baslev-Clausen, D. Brook, Edward J. Dallmayr, R. Fain, X. Lee, J. E. Mitchell, L. E. Pascual, O. Romanini, D. Rosen, J. Schuepbach, S. https://ir.library.oregonstate.edu/concern/articles/g158bn68g English [eng] eng unknown Copernicus Publications https://ir.library.oregonstate.edu/concern/articles/g158bn68g Attribution 3.0 United States Article ftoregonstate 2024-07-22T18:06:03Z 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. Article in Journal/Newspaper Greenland ice core North Greenland ScholarsArchive@OSU (Oregon State University) |
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ScholarsArchive@OSU (Oregon State University) |
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ftoregonstate |
language |
English unknown |
description |
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. |
format |
Article in Journal/Newspaper |
author |
Chappellaz, J. Stowasser, C. Blunier, T. Baslev-Clausen, D. Brook, Edward J. Dallmayr, R. Fain, X. Lee, J. E. Mitchell, L. E. Pascual, O. Romanini, D. Rosen, J. Schuepbach, S. |
spellingShingle |
Chappellaz, J. Stowasser, C. Blunier, T. Baslev-Clausen, D. Brook, Edward J. Dallmayr, R. Fain, X. Lee, J. E. Mitchell, L. E. Pascual, O. Romanini, D. Rosen, J. Schuepbach, S. High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
author_facet |
Chappellaz, J. Stowasser, C. Blunier, T. Baslev-Clausen, D. Brook, Edward J. Dallmayr, R. Fain, X. Lee, J. E. Mitchell, L. E. Pascual, O. Romanini, D. Rosen, J. Schuepbach, S. |
author_sort |
Chappellaz, J. |
title |
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
title_short |
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
title_full |
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
title_fullStr |
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
title_full_unstemmed |
High-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the NEEM ice core |
title_sort |
high-resolution glacial and deglacial record of atmospheric methane by continuous-flow and laser spectrometer analysis along the neem ice core |
publisher |
Copernicus Publications |
url |
https://ir.library.oregonstate.edu/concern/articles/g158bn68g |
genre |
Greenland ice core North Greenland |
genre_facet |
Greenland ice core North Greenland |
op_relation |
https://ir.library.oregonstate.edu/concern/articles/g158bn68g |
op_rights |
Attribution 3.0 United States |
_version_ |
1810447177461268480 |