Disparate energy sources for slow and fast Dansgaard–Oeschger cycles
During the Late Pleistocene, Dansgaard–Oeschger (DO) cycles triggered warming events that were as abrupt as the present-day human-induced warming. However, in the absence of a periodic forcing operating on millennial timescales, the main energy sources of DO cycles remain debated. Here, we identify...
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ftcopernicus:oai:publications.copernicus.org:cp109611 2023-08-15T12:41:29+02:00 Disparate energy sources for slow and fast Dansgaard–Oeschger cycles Liebrand, Diederik Bakker, Anouk T. M. Johnstone, Heather J. H. Miller, Charlotte S. 2023-07-21 application/pdf https://doi.org/10.5194/cp-19-1447-2023 https://cp.copernicus.org/articles/19/1447/2023/ eng eng doi:10.5194/cp-19-1447-2023 https://cp.copernicus.org/articles/19/1447/2023/ eISSN: 1814-9332 Text 2023 ftcopernicus https://doi.org/10.5194/cp-19-1447-2023 2023-07-24T16:24:16Z During the Late Pleistocene, Dansgaard–Oeschger (DO) cycles triggered warming events that were as abrupt as the present-day human-induced warming. However, in the absence of a periodic forcing operating on millennial timescales, the main energy sources of DO cycles remain debated. Here, we identify the energy sources of DO cycles by applying a bispectral analysis to the North Greenland Ice Core Project (NGRIP) oxygen isotope ( δ 18 O ice ) record; a 123 kyr long proxy record of air temperatures ( T air ) over Greenland. For both modes of DO cyclicity – slow and fast – we detect disparate energy sources. Slow DO cycles, marked by multi-millennial periodicities in the 12.5 to 2.5 kyr bandwidth, receive energy from astronomical periodicities. Fast DO cycles, characterized by millennial periodicities in the 1.5 ± 0.5 kyr range, receive energy from centennial periodicities. We propose cryospheric and oceanic mechanisms that facilitate the transfer of energy from known sources to slow and fast DO cycles, respectively. Our findings stress the importance of understanding energy-transfer mechanisms across a broad range of timescales to explain the origins of climate cycles without primary periodic energy sources. Text Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project Copernicus Publications: E-Journals Greenland Climate of the Past 19 7 1447 1459 |
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Copernicus Publications: E-Journals |
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ftcopernicus |
language |
English |
description |
During the Late Pleistocene, Dansgaard–Oeschger (DO) cycles triggered warming events that were as abrupt as the present-day human-induced warming. However, in the absence of a periodic forcing operating on millennial timescales, the main energy sources of DO cycles remain debated. Here, we identify the energy sources of DO cycles by applying a bispectral analysis to the North Greenland Ice Core Project (NGRIP) oxygen isotope ( δ 18 O ice ) record; a 123 kyr long proxy record of air temperatures ( T air ) over Greenland. For both modes of DO cyclicity – slow and fast – we detect disparate energy sources. Slow DO cycles, marked by multi-millennial periodicities in the 12.5 to 2.5 kyr bandwidth, receive energy from astronomical periodicities. Fast DO cycles, characterized by millennial periodicities in the 1.5 ± 0.5 kyr range, receive energy from centennial periodicities. We propose cryospheric and oceanic mechanisms that facilitate the transfer of energy from known sources to slow and fast DO cycles, respectively. Our findings stress the importance of understanding energy-transfer mechanisms across a broad range of timescales to explain the origins of climate cycles without primary periodic energy sources. |
format |
Text |
author |
Liebrand, Diederik Bakker, Anouk T. M. Johnstone, Heather J. H. Miller, Charlotte S. |
spellingShingle |
Liebrand, Diederik Bakker, Anouk T. M. Johnstone, Heather J. H. Miller, Charlotte S. Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
author_facet |
Liebrand, Diederik Bakker, Anouk T. M. Johnstone, Heather J. H. Miller, Charlotte S. |
author_sort |
Liebrand, Diederik |
title |
Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
title_short |
Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
title_full |
Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
title_fullStr |
Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
title_full_unstemmed |
Disparate energy sources for slow and fast Dansgaard–Oeschger cycles |
title_sort |
disparate energy sources for slow and fast dansgaard–oeschger cycles |
publishDate |
2023 |
url |
https://doi.org/10.5194/cp-19-1447-2023 https://cp.copernicus.org/articles/19/1447/2023/ |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project |
genre_facet |
Greenland Greenland ice core Greenland Ice core Project ice core NGRIP North Greenland North Greenland Ice Core Project |
op_source |
eISSN: 1814-9332 |
op_relation |
doi:10.5194/cp-19-1447-2023 https://cp.copernicus.org/articles/19/1447/2023/ |
op_doi |
https://doi.org/10.5194/cp-19-1447-2023 |
container_title |
Climate of the Past |
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19 |
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7 |
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1447 |
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1459 |
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1774294777602244608 |