A salty deep ocean as a prerequisite for glacial termination
Deglacial transitions of the middle to late Pleistocene (terminations) are linked to gradual changes in insolation accompanied by abrupt shifts in ocean circulation. However, the reason these deglacial abrupt events are so special compared with their sub-glacial-maximum analogues, in particular with...
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ftunivutrecht:oai:dspace.library.uu.nl:1874/413915 2023-12-10T09:41:38+01:00 A salty deep ocean as a prerequisite for glacial termination Knorr, Gregor Barker, Stephen Zhang, Xu Lohmann, Gerrit Gong, Xun Gierz, Paul Stepanek, Christian Stap, Lennert Marine and Atmospheric Research Sub Dynamics Meteorology 2021-12-03 application/pdf https://dspace.library.uu.nl/handle/1874/413915 eng eng https://dspace.library.uu.nl/handle/1874/413915 info:eu-repo/semantics/OpenAccess 2021 ftunivutrecht 2023-11-15T23:19:55Z Deglacial transitions of the middle to late Pleistocene (terminations) are linked to gradual changes in insolation accompanied by abrupt shifts in ocean circulation. However, the reason these deglacial abrupt events are so special compared with their sub-glacial-maximum analogues, in particular with respect to the exaggerated warming observed across Antarctica, remains unclear. Here we show that an increase in the relative importance of salt versus temperature stratification in the glacial deep South Atlantic decreases the potential cooling effect of waters that may be upwelled in response to abrupt perturbations in ocean circulation, as compared with sub-glacial-maximum conditions. Using a comprehensive coupled atmosphere–ocean general circulation model, we then demonstrate that an increase in deep-ocean salinity stratification stabilizes relatively warm waters in the glacial deep ocean, which amplifies the high southern latitude surface ocean temperature response to an abrupt weakening of the Atlantic meridional overturning circulation during deglaciation. The mechanism can produce a doubling in the net rate of warming across Antarctica on a multicentennial timescale when starting from full glacial conditions (as compared with interglacial or subglacial conditions) and therefore helps to explain the large magnitude and rapidity of glacial terminations during the late Quaternary. Other/Unknown Material Antarc* Antarctica Utrecht University Repository |
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Open Polar |
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Utrecht University Repository |
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ftunivutrecht |
language |
English |
description |
Deglacial transitions of the middle to late Pleistocene (terminations) are linked to gradual changes in insolation accompanied by abrupt shifts in ocean circulation. However, the reason these deglacial abrupt events are so special compared with their sub-glacial-maximum analogues, in particular with respect to the exaggerated warming observed across Antarctica, remains unclear. Here we show that an increase in the relative importance of salt versus temperature stratification in the glacial deep South Atlantic decreases the potential cooling effect of waters that may be upwelled in response to abrupt perturbations in ocean circulation, as compared with sub-glacial-maximum conditions. Using a comprehensive coupled atmosphere–ocean general circulation model, we then demonstrate that an increase in deep-ocean salinity stratification stabilizes relatively warm waters in the glacial deep ocean, which amplifies the high southern latitude surface ocean temperature response to an abrupt weakening of the Atlantic meridional overturning circulation during deglaciation. The mechanism can produce a doubling in the net rate of warming across Antarctica on a multicentennial timescale when starting from full glacial conditions (as compared with interglacial or subglacial conditions) and therefore helps to explain the large magnitude and rapidity of glacial terminations during the late Quaternary. |
author2 |
Marine and Atmospheric Research Sub Dynamics Meteorology |
author |
Knorr, Gregor Barker, Stephen Zhang, Xu Lohmann, Gerrit Gong, Xun Gierz, Paul Stepanek, Christian Stap, Lennert |
spellingShingle |
Knorr, Gregor Barker, Stephen Zhang, Xu Lohmann, Gerrit Gong, Xun Gierz, Paul Stepanek, Christian Stap, Lennert A salty deep ocean as a prerequisite for glacial termination |
author_facet |
Knorr, Gregor Barker, Stephen Zhang, Xu Lohmann, Gerrit Gong, Xun Gierz, Paul Stepanek, Christian Stap, Lennert |
author_sort |
Knorr, Gregor |
title |
A salty deep ocean as a prerequisite for glacial termination |
title_short |
A salty deep ocean as a prerequisite for glacial termination |
title_full |
A salty deep ocean as a prerequisite for glacial termination |
title_fullStr |
A salty deep ocean as a prerequisite for glacial termination |
title_full_unstemmed |
A salty deep ocean as a prerequisite for glacial termination |
title_sort |
salty deep ocean as a prerequisite for glacial termination |
publishDate |
2021 |
url |
https://dspace.library.uu.nl/handle/1874/413915 |
genre |
Antarc* Antarctica |
genre_facet |
Antarc* Antarctica |
op_relation |
https://dspace.library.uu.nl/handle/1874/413915 |
op_rights |
info:eu-repo/semantics/OpenAccess |
_version_ |
1784902404245815296 |