Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry
Here, we compare the ocean overturning circulation of the early Eocene (47–56 Ma) in eight coupled climate model simulations from the Deep-Time Model Intercomparison Project (DeepMIP) and investigate the causes of the observed inter-model spread. The most common global meridional overturning circula...
Published in: | Paleoceanography and Paleoclimatology |
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2022
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Online Access: | https://hdl.handle.net/1983/2791d47c-29c8-4577-b590-0324a098c908 https://research-information.bris.ac.uk/en/publications/2791d47c-29c8-4577-b590-0324a098c908 https://doi.org/10.1029/2021PA004329 |
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ftubristolcris:oai:research-information.bris.ac.uk:publications/2791d47c-29c8-4577-b590-0324a098c908 2024-04-28T08:31:02+00:00 Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry Zhang, Yurui Boer, Agatha M. Lunt, Daniel J. Hutchinson, David K. Ross, Phoebe Flierdt, Tina Sexton, Philip Coxall, Helen K. Steinig, Sebastian Ladant, Jean‐baptiste Zhu, Jiang Donnadieu, Yannick Zhang, Zhongshi Chan, Wing‐le Abe‐ouchi, Ayako Niezgodzki, Igor Lohmann, Gerrit Knorr, Gregor Poulsen, Christopher J. Huber, Matt 2022-02-19 https://hdl.handle.net/1983/2791d47c-29c8-4577-b590-0324a098c908 https://research-information.bris.ac.uk/en/publications/2791d47c-29c8-4577-b590-0324a098c908 https://doi.org/10.1029/2021PA004329 eng eng https://research-information.bris.ac.uk/en/publications/2791d47c-29c8-4577-b590-0324a098c908 info:eu-repo/semantics/restrictedAccess Zhang , Y , Boer , A M , Lunt , D J , Hutchinson , D K , Ross , P , Flierdt , T , Sexton , P , Coxall , H K , Steinig , S , Ladant , J , Zhu , J , Donnadieu , Y , Zhang , Z , Chan , W , Abe‐ouchi , A , Niezgodzki , I , Lohmann , G , Knorr , G , Poulsen , C J & Huber , M 2022 , ' Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry ' , Paleoceanography and Paleoclimatology , vol. 37 , no. 3 , e2021PA004329 . https://doi.org/10.1029/2021PA004329 article 2022 ftubristolcris https://doi.org/10.1029/2021PA004329 2024-04-03T16:09:18Z Here, we compare the ocean overturning circulation of the early Eocene (47–56 Ma) in eight coupled climate model simulations from the Deep-Time Model Intercomparison Project (DeepMIP) and investigate the causes of the observed inter-model spread. The most common global meridional overturning circulation (MOC) feature of these simulations is the anticlockwise bottom cell, fed by sinking in the Southern Ocean. In the North Pacific, one model (GFDL) displays strong deepwater formation and one model (CESM) shows weak deepwater formation, while in the Atlantic two models show signs of weak intermediate water formation (MIROC and NorESM). The location of the Southern Ocean deepwater formation sites varies among models and relates to small differences in model geometry of the Southern Ocean gateways. Globally, convection occurs in the basins with smallest local freshwater gain from the atmosphere. The global MOC is insensitive to atmospheric CO2 concentrations from 1× (i.e., 280 ppm) to 3× (840 ppm) pre-industrial levels. Only two models have simulations with higher CO2 (i.e., CESM and GFDL) and these show divergent responses, with a collapsed and active MOC, respectively, possibly due to differences in spin-up conditions. Combining the multiple model results with available proxy data on abyssal ocean circulation highlights that strong Southern Hemisphere-driven overturning is the most likely feature of the early Eocene. In the North Atlantic, unlike the present day, neither model results nor proxy data suggest deepwater formation in the open ocean during the early Eocene, while the evidence for deepwater formation in the North Pacific remains inconclusive. Article in Journal/Newspaper North Atlantic Southern Ocean University of Bristol: Bristol Research Paleoceanography and Paleoclimatology 37 3 |
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Open Polar |
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University of Bristol: Bristol Research |
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ftubristolcris |
language |
English |
description |
Here, we compare the ocean overturning circulation of the early Eocene (47–56 Ma) in eight coupled climate model simulations from the Deep-Time Model Intercomparison Project (DeepMIP) and investigate the causes of the observed inter-model spread. The most common global meridional overturning circulation (MOC) feature of these simulations is the anticlockwise bottom cell, fed by sinking in the Southern Ocean. In the North Pacific, one model (GFDL) displays strong deepwater formation and one model (CESM) shows weak deepwater formation, while in the Atlantic two models show signs of weak intermediate water formation (MIROC and NorESM). The location of the Southern Ocean deepwater formation sites varies among models and relates to small differences in model geometry of the Southern Ocean gateways. Globally, convection occurs in the basins with smallest local freshwater gain from the atmosphere. The global MOC is insensitive to atmospheric CO2 concentrations from 1× (i.e., 280 ppm) to 3× (840 ppm) pre-industrial levels. Only two models have simulations with higher CO2 (i.e., CESM and GFDL) and these show divergent responses, with a collapsed and active MOC, respectively, possibly due to differences in spin-up conditions. Combining the multiple model results with available proxy data on abyssal ocean circulation highlights that strong Southern Hemisphere-driven overturning is the most likely feature of the early Eocene. In the North Atlantic, unlike the present day, neither model results nor proxy data suggest deepwater formation in the open ocean during the early Eocene, while the evidence for deepwater formation in the North Pacific remains inconclusive. |
format |
Article in Journal/Newspaper |
author |
Zhang, Yurui Boer, Agatha M. Lunt, Daniel J. Hutchinson, David K. Ross, Phoebe Flierdt, Tina Sexton, Philip Coxall, Helen K. Steinig, Sebastian Ladant, Jean‐baptiste Zhu, Jiang Donnadieu, Yannick Zhang, Zhongshi Chan, Wing‐le Abe‐ouchi, Ayako Niezgodzki, Igor Lohmann, Gerrit Knorr, Gregor Poulsen, Christopher J. Huber, Matt |
spellingShingle |
Zhang, Yurui Boer, Agatha M. Lunt, Daniel J. Hutchinson, David K. Ross, Phoebe Flierdt, Tina Sexton, Philip Coxall, Helen K. Steinig, Sebastian Ladant, Jean‐baptiste Zhu, Jiang Donnadieu, Yannick Zhang, Zhongshi Chan, Wing‐le Abe‐ouchi, Ayako Niezgodzki, Igor Lohmann, Gerrit Knorr, Gregor Poulsen, Christopher J. Huber, Matt Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
author_facet |
Zhang, Yurui Boer, Agatha M. Lunt, Daniel J. Hutchinson, David K. Ross, Phoebe Flierdt, Tina Sexton, Philip Coxall, Helen K. Steinig, Sebastian Ladant, Jean‐baptiste Zhu, Jiang Donnadieu, Yannick Zhang, Zhongshi Chan, Wing‐le Abe‐ouchi, Ayako Niezgodzki, Igor Lohmann, Gerrit Knorr, Gregor Poulsen, Christopher J. Huber, Matt |
author_sort |
Zhang, Yurui |
title |
Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
title_short |
Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
title_full |
Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
title_fullStr |
Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
title_full_unstemmed |
Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
title_sort |
early eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
publishDate |
2022 |
url |
https://hdl.handle.net/1983/2791d47c-29c8-4577-b590-0324a098c908 https://research-information.bris.ac.uk/en/publications/2791d47c-29c8-4577-b590-0324a098c908 https://doi.org/10.1029/2021PA004329 |
genre |
North Atlantic Southern Ocean |
genre_facet |
North Atlantic Southern Ocean |
op_source |
Zhang , Y , Boer , A M , Lunt , D J , Hutchinson , D K , Ross , P , Flierdt , T , Sexton , P , Coxall , H K , Steinig , S , Ladant , J , Zhu , J , Donnadieu , Y , Zhang , Z , Chan , W , Abe‐ouchi , A , Niezgodzki , I , Lohmann , G , Knorr , G , Poulsen , C J & Huber , M 2022 , ' Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry ' , Paleoceanography and Paleoclimatology , vol. 37 , no. 3 , e2021PA004329 . https://doi.org/10.1029/2021PA004329 |
op_relation |
https://research-information.bris.ac.uk/en/publications/2791d47c-29c8-4577-b590-0324a098c908 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1029/2021PA004329 |
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Paleoceanography and Paleoclimatology |
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37 |
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3 |
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1797588701659791360 |