Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core
The total air content (TAC) of polar ice cores has long been considered a potential proxy for past ice sheet elevation. Recent work, however, has shown that a variety of other factors also influence this parameter. In this paper we present a high-resolution TAC record from the South Pole (SPC14) ice...
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ftnonlinearchiv:oai:noa.gwlb.de:cop_mods_00066216 2023-06-11T04:12:19+02:00 Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core Epifanio, Jenna A. Brook, Edward J. Buizert, Christo Pettit, Erin C. Edwards, Jon S. Fegyveresi, John M. Sowers, Todd A. Severinghaus, Jeffrey P. Kahle, Emma C. 2023-05 electronic https://doi.org/10.5194/egusphere-2023-578 https://noa.gwlb.de/receive/cop_mods_00066216 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064709/egusphere-2023-578.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-578/egusphere-2023-578.pdf eng eng Copernicus Publications https://doi.org/10.5194/egusphere-2023-578 https://noa.gwlb.de/receive/cop_mods_00066216 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064709/egusphere-2023-578.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-578/egusphere-2023-578.pdf https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess article Verlagsveröffentlichung article Text doc-type:article 2023 ftnonlinearchiv https://doi.org/10.5194/egusphere-2023-578 2023-05-07T23:18:00Z The total air content (TAC) of polar ice cores has long been considered a potential proxy for past ice sheet elevation. Recent work, however, has shown that a variety of other factors also influence this parameter. In this paper we present a high-resolution TAC record from the South Pole (SPC14) ice core covering the last 54,000 years and discuss the implications of the data for interpreting TAC from ice cores. The SPC14 TAC record shows multiple features of interest, including (1) long-term orbital-scale variability, (2) millennial-scale variability in the Holocene and last glacial period, and (3) a period of stability from 35 ka to 25 ka. The longer, orbital-scale variations in TAC are highly correlated with integrated summer insolation (ISI), corroborating the potential of TAC to provide an independent dating tool via orbital tuning. Large millennial-scale variability in TAC during the last glacial period is positively correlated with past accumulation rate reconstructions as well as the δ15N of N2, a firn thickness proxy. These TAC variations are too large to be controlled by direct effects of temperature and too rapid to be tied to elevation changes. We propose that grain size metamorphism near the firn surface is likely to explain these changes. We note, however, that at sites with different climate histories than the South Pole, TAC variations may be dominated by other processes. Our observations of millennial-scale variations in TAC show a different relationship with accumulation rate than observed at sites in Greenland. Article in Journal/Newspaper Greenland ice core Ice Sheet South pole Niedersächsisches Online-Archiv NOA Greenland Isi ENVELOPE(-38.550,-38.550,65.617,65.617) South Pole Tac ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
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Open Polar |
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Niedersächsisches Online-Archiv NOA |
op_collection_id |
ftnonlinearchiv |
language |
English |
topic |
article Verlagsveröffentlichung |
spellingShingle |
article Verlagsveröffentlichung Epifanio, Jenna A. Brook, Edward J. Buizert, Christo Pettit, Erin C. Edwards, Jon S. Fegyveresi, John M. Sowers, Todd A. Severinghaus, Jeffrey P. Kahle, Emma C. Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
topic_facet |
article Verlagsveröffentlichung |
description |
The total air content (TAC) of polar ice cores has long been considered a potential proxy for past ice sheet elevation. Recent work, however, has shown that a variety of other factors also influence this parameter. In this paper we present a high-resolution TAC record from the South Pole (SPC14) ice core covering the last 54,000 years and discuss the implications of the data for interpreting TAC from ice cores. The SPC14 TAC record shows multiple features of interest, including (1) long-term orbital-scale variability, (2) millennial-scale variability in the Holocene and last glacial period, and (3) a period of stability from 35 ka to 25 ka. The longer, orbital-scale variations in TAC are highly correlated with integrated summer insolation (ISI), corroborating the potential of TAC to provide an independent dating tool via orbital tuning. Large millennial-scale variability in TAC during the last glacial period is positively correlated with past accumulation rate reconstructions as well as the δ15N of N2, a firn thickness proxy. These TAC variations are too large to be controlled by direct effects of temperature and too rapid to be tied to elevation changes. We propose that grain size metamorphism near the firn surface is likely to explain these changes. We note, however, that at sites with different climate histories than the South Pole, TAC variations may be dominated by other processes. Our observations of millennial-scale variations in TAC show a different relationship with accumulation rate than observed at sites in Greenland. |
format |
Article in Journal/Newspaper |
author |
Epifanio, Jenna A. Brook, Edward J. Buizert, Christo Pettit, Erin C. Edwards, Jon S. Fegyveresi, John M. Sowers, Todd A. Severinghaus, Jeffrey P. Kahle, Emma C. |
author_facet |
Epifanio, Jenna A. Brook, Edward J. Buizert, Christo Pettit, Erin C. Edwards, Jon S. Fegyveresi, John M. Sowers, Todd A. Severinghaus, Jeffrey P. Kahle, Emma C. |
author_sort |
Epifanio, Jenna A. |
title |
Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
title_short |
Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
title_full |
Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
title_fullStr |
Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
title_full_unstemmed |
Millennial and orbital-scale variability in a 54,000-year record of total air content from the South Pole ice core |
title_sort |
millennial and orbital-scale variability in a 54,000-year record of total air content from the south pole ice core |
publisher |
Copernicus Publications |
publishDate |
2023 |
url |
https://doi.org/10.5194/egusphere-2023-578 https://noa.gwlb.de/receive/cop_mods_00066216 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064709/egusphere-2023-578.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-578/egusphere-2023-578.pdf |
long_lat |
ENVELOPE(-38.550,-38.550,65.617,65.617) ENVELOPE(-59.517,-59.517,-62.500,-62.500) |
geographic |
Greenland Isi South Pole Tac |
geographic_facet |
Greenland Isi South Pole Tac |
genre |
Greenland ice core Ice Sheet South pole |
genre_facet |
Greenland ice core Ice Sheet South pole |
op_relation |
https://doi.org/10.5194/egusphere-2023-578 https://noa.gwlb.de/receive/cop_mods_00066216 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00064709/egusphere-2023-578.pdf https://egusphere.copernicus.org/preprints/2023/egusphere-2023-578/egusphere-2023-578.pdf |
op_rights |
https://creativecommons.org/licenses/by/4.0/ uneingeschränkt info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.5194/egusphere-2023-578 |
_version_ |
1768388085127577600 |