Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period
In order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores provide the means to do this. Here we analyze the ultrahigh-resolution CH4 record of the...
Published in: | Global Biogeochemical Cycles |
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Online Access: | http://nora.nerc.ac.uk/id/eprint/517097/ https://nora.nerc.ac.uk/id/eprint/517097/1/gbc20529.pdf https://doi.org/10.1002/2016GB005570 |
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ftnerc:oai:nora.nerc.ac.uk:517097 2023-05-15T13:49:34+02:00 Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period Rhodes, Rachael H. Brook, Edward J. McConnell, Joseph R. Blunier, Thomas Sime, Louise C. Faïn, Xavier Mulvaney, Robert 2017-03 text http://nora.nerc.ac.uk/id/eprint/517097/ https://nora.nerc.ac.uk/id/eprint/517097/1/gbc20529.pdf https://doi.org/10.1002/2016GB005570 en eng Wiley https://nora.nerc.ac.uk/id/eprint/517097/1/gbc20529.pdf Rhodes, Rachael H.; Brook, Edward J.; McConnell, Joseph R.; Blunier, Thomas; Sime, Louise C. orcid:0000-0002-9093-7926 Faïn, Xavier; Mulvaney, Robert orcid:0000-0002-5372-8148 . 2017 Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period. Global Biogeochemical Cycles, 31 (3). 575-590. https://doi.org/10.1002/2016GB005570 <https://doi.org/10.1002/2016GB005570> Publication - Article PeerReviewed 2017 ftnerc https://doi.org/10.1002/2016GB005570 2023-02-04T19:44:58Z In order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores provide the means to do this. Here we analyze the ultrahigh-resolution CH4 record of the West Antarctic Ice Sheet Divide ice core 67.2–9.8 ka and find novel, atmospheric CH4 variability at centennial time scales throughout the record. This signal is characterized by recurrence intervals within a broad 80–500 year range, but we find that age-scale uncertainties complicate the possible isolation of any periodic frequency. Lower signal amplitudes in the Last Glacial relative to the Holocene may be related to incongruent effects of firn-based signal smoothing processes. Within interstadial and stadial periods, the peak-to-peak signal amplitudes vary in proportion to the underlying millennial-scale oscillations in CH4 concentration—the relative amplitude change is constant. We propose that the centennial CH4 signal is related to tropical climate variability that influences predominantly low-latitude wetland CH4 emissions Article in Journal/Newspaper Antarc* Antarctic ice core Ice Sheet Natural Environment Research Council: NERC Open Research Archive Antarctic West Antarctic Ice Sheet Global Biogeochemical Cycles 31 3 575 590 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
In order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores provide the means to do this. Here we analyze the ultrahigh-resolution CH4 record of the West Antarctic Ice Sheet Divide ice core 67.2–9.8 ka and find novel, atmospheric CH4 variability at centennial time scales throughout the record. This signal is characterized by recurrence intervals within a broad 80–500 year range, but we find that age-scale uncertainties complicate the possible isolation of any periodic frequency. Lower signal amplitudes in the Last Glacial relative to the Holocene may be related to incongruent effects of firn-based signal smoothing processes. Within interstadial and stadial periods, the peak-to-peak signal amplitudes vary in proportion to the underlying millennial-scale oscillations in CH4 concentration—the relative amplitude change is constant. We propose that the centennial CH4 signal is related to tropical climate variability that influences predominantly low-latitude wetland CH4 emissions |
format |
Article in Journal/Newspaper |
author |
Rhodes, Rachael H. Brook, Edward J. McConnell, Joseph R. Blunier, Thomas Sime, Louise C. Faïn, Xavier Mulvaney, Robert |
spellingShingle |
Rhodes, Rachael H. Brook, Edward J. McConnell, Joseph R. Blunier, Thomas Sime, Louise C. Faïn, Xavier Mulvaney, Robert Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
author_facet |
Rhodes, Rachael H. Brook, Edward J. McConnell, Joseph R. Blunier, Thomas Sime, Louise C. Faïn, Xavier Mulvaney, Robert |
author_sort |
Rhodes, Rachael H. |
title |
Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
title_short |
Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
title_full |
Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
title_fullStr |
Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
title_full_unstemmed |
Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period |
title_sort |
atmospheric methane variability: centennial-scale signals in the last glacial period |
publisher |
Wiley |
publishDate |
2017 |
url |
http://nora.nerc.ac.uk/id/eprint/517097/ https://nora.nerc.ac.uk/id/eprint/517097/1/gbc20529.pdf https://doi.org/10.1002/2016GB005570 |
geographic |
Antarctic West Antarctic Ice Sheet |
geographic_facet |
Antarctic West Antarctic Ice Sheet |
genre |
Antarc* Antarctic ice core Ice Sheet |
genre_facet |
Antarc* Antarctic ice core Ice Sheet |
op_relation |
https://nora.nerc.ac.uk/id/eprint/517097/1/gbc20529.pdf Rhodes, Rachael H.; Brook, Edward J.; McConnell, Joseph R.; Blunier, Thomas; Sime, Louise C. orcid:0000-0002-9093-7926 Faïn, Xavier; Mulvaney, Robert orcid:0000-0002-5372-8148 . 2017 Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period. Global Biogeochemical Cycles, 31 (3). 575-590. https://doi.org/10.1002/2016GB005570 <https://doi.org/10.1002/2016GB005570> |
op_doi |
https://doi.org/10.1002/2016GB005570 |
container_title |
Global Biogeochemical Cycles |
container_volume |
31 |
container_issue |
3 |
container_start_page |
575 |
op_container_end_page |
590 |
_version_ |
1766251662470545408 |