Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland
During the last glacial interval, the Northern Hemisphere climate was punctuated by a series of abrupt changes between two characteristic climate regimes. The existence of stadial (cold) and interstadial (milder) periods is typically attributed to a hypothesised bistability in the glacial North Atla...
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ftunivmob:oai:nmbu.brage.unit.no:11250/3069298 2023-06-11T04:12:07+02:00 Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland Riechers, Keno Gorjão, Leonardo Rydin Hassanibesheli, Forough Lind, Pedro Witthaut, Dirk Boers, Niklas 2023-05-16T09:04:18Z application/pdf https://hdl.handle.net/11250/3069298 https://doi.org/10.5194/esd-14-593-2023 eng eng EU – Horisont Europa (EC/HEU): 820970 Earth System Dynamics. 2023, 14 (3), 593-607. urn:issn:2190-4979 https://hdl.handle.net/11250/3069298 https://doi.org/10.5194/esd-14-593-2023 cristin:2147710 593-607 14 Earth System Dynamics 3 Peer reviewed Journal article 2023 ftunivmob https://doi.org/10.5194/esd-14-593-2023 2023-05-31T22:46:55Z During the last glacial interval, the Northern Hemisphere climate was punctuated by a series of abrupt changes between two characteristic climate regimes. The existence of stadial (cold) and interstadial (milder) periods is typically attributed to a hypothesised bistability in the glacial North Atlantic climate system, allowing for rapid transitions from the stadial to the interstadial state – the so-called Dansgaard–Oeschger (DO) events – and more gradual yet still fairly abrupt reverse shifts. The physical mechanisms driving these regime transitions remain debated. DO events are characterised by substantial warming over Greenland and a reorganisation of the Northern Hemisphere atmospheric circulation, which are evident from concomitant shifts in the δ18O ratios and dust concentration records from Greenland ice cores. Treating the combined δ18O and dust record obtained by the North Greenland Ice Core Project (NGRIP) as a realisation of a two-dimensional, time-homogeneous, and Markovian stochastic process, we present a reconstruction of its underlying deterministic drift based on the leading-order terms of the Kramers–Moyal equation. The analysis reveals two basins of attraction in the two-dimensional state space that can be identified with the stadial and interstadial regimes. The drift term of the dust exhibits a double-fold bifurcation structure, while – in contrast to prevailing assumptions – the δ18O component of the drift is clearly mono-stable. This suggests that the last glacial's Greenland temperatures should not be regarded as an intrinsically bistable climate variable. Instead, the two-regime nature of the δ18O record is apparently inherited from a coupling to another bistable climate process. In contrast, the bistability evidenced in the dust drift points to the presence of two stable circulation regimes of the last glacial's Northern Hemisphere atmosphere. Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from ... Article in Journal/Newspaper Greenland Greenland ice core Greenland Ice core Project Greenland ice cores ice core NGRIP North Atlantic North Greenland North Greenland Ice Core Project Open archive Norwegian University of Life Sciences: Brage NMBU Greenland Earth System Dynamics 14 3 593 607 |
institution |
Open Polar |
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Open archive Norwegian University of Life Sciences: Brage NMBU |
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ftunivmob |
language |
English |
description |
During the last glacial interval, the Northern Hemisphere climate was punctuated by a series of abrupt changes between two characteristic climate regimes. The existence of stadial (cold) and interstadial (milder) periods is typically attributed to a hypothesised bistability in the glacial North Atlantic climate system, allowing for rapid transitions from the stadial to the interstadial state – the so-called Dansgaard–Oeschger (DO) events – and more gradual yet still fairly abrupt reverse shifts. The physical mechanisms driving these regime transitions remain debated. DO events are characterised by substantial warming over Greenland and a reorganisation of the Northern Hemisphere atmospheric circulation, which are evident from concomitant shifts in the δ18O ratios and dust concentration records from Greenland ice cores. Treating the combined δ18O and dust record obtained by the North Greenland Ice Core Project (NGRIP) as a realisation of a two-dimensional, time-homogeneous, and Markovian stochastic process, we present a reconstruction of its underlying deterministic drift based on the leading-order terms of the Kramers–Moyal equation. The analysis reveals two basins of attraction in the two-dimensional state space that can be identified with the stadial and interstadial regimes. The drift term of the dust exhibits a double-fold bifurcation structure, while – in contrast to prevailing assumptions – the δ18O component of the drift is clearly mono-stable. This suggests that the last glacial's Greenland temperatures should not be regarded as an intrinsically bistable climate variable. Instead, the two-regime nature of the δ18O record is apparently inherited from a coupling to another bistable climate process. In contrast, the bistability evidenced in the dust drift points to the presence of two stable circulation regimes of the last glacial's Northern Hemisphere atmosphere. Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from ... |
format |
Article in Journal/Newspaper |
author |
Riechers, Keno Gorjão, Leonardo Rydin Hassanibesheli, Forough Lind, Pedro Witthaut, Dirk Boers, Niklas |
spellingShingle |
Riechers, Keno Gorjão, Leonardo Rydin Hassanibesheli, Forough Lind, Pedro Witthaut, Dirk Boers, Niklas Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
author_facet |
Riechers, Keno Gorjão, Leonardo Rydin Hassanibesheli, Forough Lind, Pedro Witthaut, Dirk Boers, Niklas |
author_sort |
Riechers, Keno |
title |
Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
title_short |
Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
title_full |
Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
title_fullStr |
Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
title_full_unstemmed |
Stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from Greenland |
title_sort |
stable stadial and interstadial states of the last glacial's climate identified in a combined stable water isotope and dust record from greenland |
publishDate |
2023 |
url |
https://hdl.handle.net/11250/3069298 https://doi.org/10.5194/esd-14-593-2023 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland Greenland ice core Greenland Ice core Project Greenland ice cores ice core NGRIP North Atlantic North Greenland North Greenland Ice Core Project |
genre_facet |
Greenland Greenland ice core Greenland Ice core Project Greenland ice cores ice core NGRIP North Atlantic North Greenland North Greenland Ice Core Project |
op_source |
593-607 14 Earth System Dynamics 3 |
op_relation |
EU – Horisont Europa (EC/HEU): 820970 Earth System Dynamics. 2023, 14 (3), 593-607. urn:issn:2190-4979 https://hdl.handle.net/11250/3069298 https://doi.org/10.5194/esd-14-593-2023 cristin:2147710 |
op_doi |
https://doi.org/10.5194/esd-14-593-2023 |
container_title |
Earth System Dynamics |
container_volume |
14 |
container_issue |
3 |
container_start_page |
593 |
op_container_end_page |
607 |
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1768387765710356480 |