Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation

Ruza F. Ivanovic; Lauren J. Gregoire; Andrew D. Wickert; Paul J. Valdes; Andrea Burke

doi:10.1002/2016GL071849

Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation

Ruza F. Ivanovic, Lauren J. Gregoire, Andrew D. Wickert, Paul J. Valdes, Andrea Burke

Research output: Contribution to journal › Article › peer-review

Abstract

Collapse of ice sheets can cause significant sea-level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran-Laurentide ice saddle (North America) ~14.5 thousand years ago (ka) using a high-resolution drainage model coupled to an ocean-atmosphere-vegetation general circulation model. Equivalent to 7.26 m global mean sea-level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1-5 °C. The greatest cooling is in the Atlantic-sector high latitudes during Boreal winter (by 5-10 °C), but there is also strong summer warming of 1-3 °C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the Bølling warming event ~14.7-14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.

Original language	English
Pages (from-to)	383-392
Number of pages	10
Journal	Geophysical Research Letters
Volume	44
Issue number	1
Early online date	9 Jan 2017
DOIs	https://doi.org/10.1002/2016GL071849
Publication status	Published - 16 Jan 2017

Keywords

AMOC
Ice sheet melt
Saddle collapse
Older Dryas

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

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10.1002/2016GL071849Licence: CC BY

Ivanovic_et_al-2017-Geophysical_Research_Letters
© 2016 The Authors. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Final published version, 6.14 MBLicence: CC BY

Cite this

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title = "Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation",

abstract = "Collapse of ice sheets can cause significant sea-level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran-Laurentide ice saddle (North America) \textasciitilde{}14.5 thousand years ago (ka) using a high-resolution drainage model coupled to an ocean-atmosphere-vegetation general circulation model. Equivalent to 7.26 m global mean sea-level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1-5 °C. The greatest cooling is in the Atlantic-sector high latitudes during Boreal winter (by 5-10 °C), but there is also strong summer warming of 1-3 °C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the B{\o}lling warming event \textasciitilde{}14.7-14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.",

keywords = "AMOC, Ice sheet melt, Saddle collapse, Older Dryas",

author = "Ivanovic, \{Ruza F.\} and Gregoire, \{Lauren J.\} and Wickert, \{Andrew D.\} and Valdes, \{Paul J.\} and Andrea Burke",

note = "RFI is funded by NERC grant \#NE/K008536/1. Numerical climate model simulations made use of the N8 HPC Centre of Excellence (N8 consortium and EPSRC Grant \#EP/K000225/1).",

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AU - Ivanovic, Ruza F.

AU - Gregoire, Lauren J.

AU - Wickert, Andrew D.

AU - Valdes, Paul J.

AU - Burke, Andrea

N1 - RFI is funded by NERC grant #NE/K008536/1. Numerical climate model simulations made use of the N8 HPC Centre of Excellence (N8 consortium and EPSRC Grant #EP/K000225/1).

PY - 2017/1/16

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N2 - Collapse of ice sheets can cause significant sea-level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran-Laurentide ice saddle (North America) ~14.5 thousand years ago (ka) using a high-resolution drainage model coupled to an ocean-atmosphere-vegetation general circulation model. Equivalent to 7.26 m global mean sea-level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1-5 °C. The greatest cooling is in the Atlantic-sector high latitudes during Boreal winter (by 5-10 °C), but there is also strong summer warming of 1-3 °C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the Bølling warming event ~14.7-14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.

AB - Collapse of ice sheets can cause significant sea-level rise and widespread climate change. We examine the climatic response to meltwater generated by the collapse of the Cordilleran-Laurentide ice saddle (North America) ~14.5 thousand years ago (ka) using a high-resolution drainage model coupled to an ocean-atmosphere-vegetation general circulation model. Equivalent to 7.26 m global mean sea-level rise in 340 years, the meltwater caused a 6 sverdrup weakening of Atlantic Meridional Overturning Circulation (AMOC) and widespread Northern Hemisphere cooling of 1-5 °C. The greatest cooling is in the Atlantic-sector high latitudes during Boreal winter (by 5-10 °C), but there is also strong summer warming of 1-3 °C over eastern North America. Following recent suggestions that the saddle collapse was triggered by the Bølling warming event ~14.7-14.5 ka, we conclude that this robust submillennial mechanism may have initiated the end of the warming and/or the Older Dryas cooling through a forced AMOC weakening.

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KW - Ice sheet melt

KW - Saddle collapse

KW - Older Dryas

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JO - Geophysical Research Letters

JF - Geophysical Research Letters

IS - 1

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Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation

Abstract

Keywords

UN SDGs

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REIMAGINATION: Reconstructing and: REIMAGINATION: REconstructing and understanding the IMplications of surface 14C AGe changes In the North Atlantic for overturning circulaTION

Andrea Burke

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Collapse of the North American ice saddle 14,500 years ago caused widespread cooling and reduced ocean overturning circulation

Abstract

Keywords

UN SDGs

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REIMAGINATION: Reconstructing and: REIMAGINATION: REconstructing and understanding the IMplications of surface 14C AGe changes In the North Atlantic for overturning circulaTION

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Andrea Burke

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