Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial
The Atlantic Meridional Overturning Circulation (AMOC) is thought to be relatively vigorous and stable during Interglacial periods on multimillennial (equilibrium) timescales. However, recent proxy (δ13C benthic) reconstructions suggest that higher frequency variability in deep water circulation may...
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ftunivbergen:oai:bora.uib.no:1956/22520 2023-05-15T16:29:50+02:00 Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial Kessler, Augustin Bouttes, Nathaelle Roche, Didier M. Ninnemann, Ulysses Silas Galaasen, Eirik Vinje Tjiputra, Jerry 2020 application/pdf https://hdl.handle.net/1956/22520 https://doi.org/10.1029/2019pa003818 eng eng American Geophysical Union urn:issn:2572-4517 https://hdl.handle.net/1956/22520 https://doi.org/10.1029/2019pa003818 cristin:1812769 Paleoceanography and Paleoclimatology. 2020, 35 (5), e2019PA003818. Attribution CC BY http://creativecommons.org/licenses/by/4.0/ Copyright 2020 The Authors. e2019PA003818 Paleoceanography and Paleoclimatology 35 5 Peer reviewed Journal article 2020 ftunivbergen https://doi.org/10.1029/2019pa003818 2023-03-14T17:43:08Z The Atlantic Meridional Overturning Circulation (AMOC) is thought to be relatively vigorous and stable during Interglacial periods on multimillennial (equilibrium) timescales. However, recent proxy (δ13C benthic) reconstructions suggest that higher frequency variability in deep water circulation may have been common during some interglacial periods, including the Last Interglacial (LIG, 130–115 ka). The origin of these isotope variations and their implications for past AMOC remain poorly understood. Using iLOVECLIM, an Earth system model of intermediate complexity (EMIC) allowing the computation of urn:x-wiley:palo:media:palo20866:palo20866-math-0001 and direct comparison to proxy reconstructions, we perform a transient experiment of the LIG (125–115 ka) forced only by boundary conditions of greenhouse gases and orbital forcings. The model simulates large centennial‐scale variations in the interior urn:x-wiley:palo:media:palo20866:palo20866-math-0002 of the North Atlantic similar in timescale and amplitude to changes resolved by high‐resolution reconstructions from the LIG. In the model, these variations are caused by changes in the relative influence of North Atlantic Deep Water (NADW) and southern source water (SSW) and are closely linked to large (∼50%) changes in AMOC strength provoked by saline input and associated deep convection areas south of Greenland. We identify regions within the subpolar North Atlantic with different sensitivity and response to changes in preformed urn:x-wiley:palo:media:palo20866:palo20866-math-0003 of NADW and to changes in NADW versus SSW influence, which is useful for proxy record interpretation. This could explain the relatively large δ13C gradient (∼0.4%0) observed at ∼3 km water depth in the subpolar North Atlantic at the inception of the last glacial. publishedVersion Article in Journal/Newspaper Greenland NADW North Atlantic Deep Water North Atlantic University of Bergen: Bergen Open Research Archive (BORA-UiB) Greenland Paleoceanography and Paleoclimatology 35 5 |
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Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
description |
The Atlantic Meridional Overturning Circulation (AMOC) is thought to be relatively vigorous and stable during Interglacial periods on multimillennial (equilibrium) timescales. However, recent proxy (δ13C benthic) reconstructions suggest that higher frequency variability in deep water circulation may have been common during some interglacial periods, including the Last Interglacial (LIG, 130–115 ka). The origin of these isotope variations and their implications for past AMOC remain poorly understood. Using iLOVECLIM, an Earth system model of intermediate complexity (EMIC) allowing the computation of urn:x-wiley:palo:media:palo20866:palo20866-math-0001 and direct comparison to proxy reconstructions, we perform a transient experiment of the LIG (125–115 ka) forced only by boundary conditions of greenhouse gases and orbital forcings. The model simulates large centennial‐scale variations in the interior urn:x-wiley:palo:media:palo20866:palo20866-math-0002 of the North Atlantic similar in timescale and amplitude to changes resolved by high‐resolution reconstructions from the LIG. In the model, these variations are caused by changes in the relative influence of North Atlantic Deep Water (NADW) and southern source water (SSW) and are closely linked to large (∼50%) changes in AMOC strength provoked by saline input and associated deep convection areas south of Greenland. We identify regions within the subpolar North Atlantic with different sensitivity and response to changes in preformed urn:x-wiley:palo:media:palo20866:palo20866-math-0003 of NADW and to changes in NADW versus SSW influence, which is useful for proxy record interpretation. This could explain the relatively large δ13C gradient (∼0.4%0) observed at ∼3 km water depth in the subpolar North Atlantic at the inception of the last glacial. publishedVersion |
format |
Article in Journal/Newspaper |
author |
Kessler, Augustin Bouttes, Nathaelle Roche, Didier M. Ninnemann, Ulysses Silas Galaasen, Eirik Vinje Tjiputra, Jerry |
spellingShingle |
Kessler, Augustin Bouttes, Nathaelle Roche, Didier M. Ninnemann, Ulysses Silas Galaasen, Eirik Vinje Tjiputra, Jerry Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
author_facet |
Kessler, Augustin Bouttes, Nathaelle Roche, Didier M. Ninnemann, Ulysses Silas Galaasen, Eirik Vinje Tjiputra, Jerry |
author_sort |
Kessler, Augustin |
title |
Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
title_short |
Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
title_full |
Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
title_fullStr |
Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
title_full_unstemmed |
Atlantic Meridional Overturning Circulation and δ13C Variability During the Last Interglacial |
title_sort |
atlantic meridional overturning circulation and δ13c variability during the last interglacial |
publisher |
American Geophysical Union |
publishDate |
2020 |
url |
https://hdl.handle.net/1956/22520 https://doi.org/10.1029/2019pa003818 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland NADW North Atlantic Deep Water North Atlantic |
genre_facet |
Greenland NADW North Atlantic Deep Water North Atlantic |
op_source |
e2019PA003818 Paleoceanography and Paleoclimatology 35 5 |
op_relation |
urn:issn:2572-4517 https://hdl.handle.net/1956/22520 https://doi.org/10.1029/2019pa003818 cristin:1812769 Paleoceanography and Paleoclimatology. 2020, 35 (5), e2019PA003818. |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/4.0/ Copyright 2020 The Authors. |
op_doi |
https://doi.org/10.1029/2019pa003818 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
35 |
container_issue |
5 |
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1766019539917602816 |