Precise interpolar phasing of abrupt climate change during the last ice age
The last glacial period exhibited abrupt Dansgaard–Oeschger climatic oscillations, evidence of which is preserved in a variety of Northern Hemisphere palaeoclimate archives1. Ice cores show that Antarctica cooled during the warm phases of the Greenland Dansgaard–Oeschger cycle and vice versa2,3, sug...
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ftuninhampshire:oai:scholars.unh.edu:faculty_pubs-1335 2023-05-15T13:37:52+02:00 Precise interpolar phasing of abrupt climate change during the last ice age WAIS Divide Project Members Souney, Joseph M. 2015-04-30T07:00:00Z https://scholars.unh.edu/faculty_pubs/336 https://doi.org/10.1038/nature14401 unknown University of New Hampshire Scholars' Repository https://scholars.unh.edu/faculty_pubs/336 https://doi.org/10.1038/nature14401 Faculty Publications Climate change Cryospheric science Palaeoceanography Palaeoclimate text 2015 ftuninhampshire https://doi.org/10.1038/nature14401 2023-04-06T17:33:56Z The last glacial period exhibited abrupt Dansgaard–Oeschger climatic oscillations, evidence of which is preserved in a variety of Northern Hemisphere palaeoclimate archives1. Ice cores show that Antarctica cooled during the warm phases of the Greenland Dansgaard–Oeschger cycle and vice versa2,3, suggesting an interhemispheric redistribution of heat through a mechanism called the bipolar seesaw4,5,6. Variations in the Atlantic meridional overturning circulation (AMOC) strength are thought to have been important, but much uncertainty remains regarding the dynamics and trigger of these abrupt events7,8,9. Key information is contained in the relative phasing of hemispheric climate variations, yet the large, poorly constrained difference between gas age and ice age and the relatively low resolution of methane records from Antarctic ice cores have so far precluded methane-based synchronization at the required sub-centennial precision2,3,10. Here we use a recently drilled high-accumulation Antarctic ice core to show that, on average, abrupt Greenland warming leads the corresponding Antarctic cooling onset by 218 ± 92 years (2σ) for Dansgaard–Oeschger events, including the Bølling event; Greenland cooling leads the corresponding onset of Antarctic warming by 208 ± 96 years. Our results demonstrate a north-to-south directionality of the abrupt climatic signal, which is propagated to the Southern Hemisphere high latitudes by oceanic rather than atmospheric processes. The similar interpolar phasing of warming and cooling transitions suggests that the transfer time of the climatic signal is independent of the AMOC background state. Our findings confirm a central role for ocean circulation in the bipolar seesaw and provide clear criteria for assessing hypotheses and model simulations of Dansgaard–Oeschger dynamics. Text Antarc* Antarctic Antarctica Dansgaard-Oeschger events Greenland ice core University of New Hampshire: Scholars Repository Antarctic Greenland Nature 520 7549 661 665 |
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Open Polar |
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University of New Hampshire: Scholars Repository |
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ftuninhampshire |
language |
unknown |
topic |
Climate change Cryospheric science Palaeoceanography Palaeoclimate |
spellingShingle |
Climate change Cryospheric science Palaeoceanography Palaeoclimate WAIS Divide Project Members Souney, Joseph M. Precise interpolar phasing of abrupt climate change during the last ice age |
topic_facet |
Climate change Cryospheric science Palaeoceanography Palaeoclimate |
description |
The last glacial period exhibited abrupt Dansgaard–Oeschger climatic oscillations, evidence of which is preserved in a variety of Northern Hemisphere palaeoclimate archives1. Ice cores show that Antarctica cooled during the warm phases of the Greenland Dansgaard–Oeschger cycle and vice versa2,3, suggesting an interhemispheric redistribution of heat through a mechanism called the bipolar seesaw4,5,6. Variations in the Atlantic meridional overturning circulation (AMOC) strength are thought to have been important, but much uncertainty remains regarding the dynamics and trigger of these abrupt events7,8,9. Key information is contained in the relative phasing of hemispheric climate variations, yet the large, poorly constrained difference between gas age and ice age and the relatively low resolution of methane records from Antarctic ice cores have so far precluded methane-based synchronization at the required sub-centennial precision2,3,10. Here we use a recently drilled high-accumulation Antarctic ice core to show that, on average, abrupt Greenland warming leads the corresponding Antarctic cooling onset by 218 ± 92 years (2σ) for Dansgaard–Oeschger events, including the Bølling event; Greenland cooling leads the corresponding onset of Antarctic warming by 208 ± 96 years. Our results demonstrate a north-to-south directionality of the abrupt climatic signal, which is propagated to the Southern Hemisphere high latitudes by oceanic rather than atmospheric processes. The similar interpolar phasing of warming and cooling transitions suggests that the transfer time of the climatic signal is independent of the AMOC background state. Our findings confirm a central role for ocean circulation in the bipolar seesaw and provide clear criteria for assessing hypotheses and model simulations of Dansgaard–Oeschger dynamics. |
format |
Text |
author |
WAIS Divide Project Members Souney, Joseph M. |
author_facet |
WAIS Divide Project Members Souney, Joseph M. |
author_sort |
WAIS Divide Project Members |
title |
Precise interpolar phasing of abrupt climate change during the last ice age |
title_short |
Precise interpolar phasing of abrupt climate change during the last ice age |
title_full |
Precise interpolar phasing of abrupt climate change during the last ice age |
title_fullStr |
Precise interpolar phasing of abrupt climate change during the last ice age |
title_full_unstemmed |
Precise interpolar phasing of abrupt climate change during the last ice age |
title_sort |
precise interpolar phasing of abrupt climate change during the last ice age |
publisher |
University of New Hampshire Scholars' Repository |
publishDate |
2015 |
url |
https://scholars.unh.edu/faculty_pubs/336 https://doi.org/10.1038/nature14401 |
geographic |
Antarctic Greenland |
geographic_facet |
Antarctic Greenland |
genre |
Antarc* Antarctic Antarctica Dansgaard-Oeschger events Greenland ice core |
genre_facet |
Antarc* Antarctic Antarctica Dansgaard-Oeschger events Greenland ice core |
op_source |
Faculty Publications |
op_relation |
https://scholars.unh.edu/faculty_pubs/336 https://doi.org/10.1038/nature14401 |
op_doi |
https://doi.org/10.1038/nature14401 |
container_title |
Nature |
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520 |
container_issue |
7549 |
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661 |
op_container_end_page |
665 |
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1766098423776280576 |