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 circul...
Published in: | Paleoceanography and Paleoclimatology |
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American Geophysical Union (AGU)
2022
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Online Access: | http://hdl.handle.net/10044/1/95076 https://doi.org/10.1029/2021pa004329 |
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ftimperialcol:oai:spiral.imperial.ac.uk:10044/1/95076 2023-05-15T16:02:34+02:00 Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry Zhang, Y Boer, AM Lunt, DJ Hutchinson, DK Ross, P Flierdt, T Sexton, P Coxall, HK Steinig, S Ladant, J Zhu, J Donnadieu, Y Zhang, Z Chan, W Abe‐Ouchi, A Niezgodzki, I Lohmann, G Knorr, G Poulsen, CJ Huber, M Natural Environment Research Council (NERC) 2022-02-14 http://hdl.handle.net/10044/1/95076 https://doi.org/10.1029/2021pa004329 en eng American Geophysical Union (AGU) Paleoceanography and Paleoclimatology 2572-4517 http://hdl.handle.net/10044/1/95076 doi:10.1029/2021pa004329 NE/P019080/1 © 2022. American Geophysical Union. All Rights Reserved. This is the accepted version of the following article: Zhang, Y., de Boer, A. M., Lunt, D. J., Hutchinson, D. K., Ross, P., van de Flierdt, T., et al. (2022). Early Eocene ocean meridional overturning circulation: The roles of atmospheric forcing and strait geometry. Paleoceanography and Paleoclimatology, 37, e2021PA004329, which has been published in final form at https://doi.org/10.1029/2021PA004329 22 1 Science & Technology Physical Sciences Life Sciences & Biomedicine Geosciences Multidisciplinary Oceanography Paleontology Geology DEEP-WATER PRODUCTION STABLE-ISOTOPE RECORD FOSSIL FISH TEETH HEAT-TRANSPORT DRAKE PASSAGE PLANT DIVERSITY COMPONENT WATER SOUTHERN-OCEAN PACIFIC-OCEAN SEAWATER SR Journal Article 2022 ftimperialcol https://doi.org/10.1029/2021pa004329 2023-02-23T23:42:41Z 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 1x (i.e. 280 ppm) to 3x (840ppm) 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 Drake Passage North Atlantic Southern Ocean Imperial College London: Spiral Drake Passage Pacific Southern Ocean Paleoceanography and Paleoclimatology 37 3 |
institution |
Open Polar |
collection |
Imperial College London: Spiral |
op_collection_id |
ftimperialcol |
language |
English |
topic |
Science & Technology Physical Sciences Life Sciences & Biomedicine Geosciences Multidisciplinary Oceanography Paleontology Geology DEEP-WATER PRODUCTION STABLE-ISOTOPE RECORD FOSSIL FISH TEETH HEAT-TRANSPORT DRAKE PASSAGE PLANT DIVERSITY COMPONENT WATER SOUTHERN-OCEAN PACIFIC-OCEAN SEAWATER SR |
spellingShingle |
Science & Technology Physical Sciences Life Sciences & Biomedicine Geosciences Multidisciplinary Oceanography Paleontology Geology DEEP-WATER PRODUCTION STABLE-ISOTOPE RECORD FOSSIL FISH TEETH HEAT-TRANSPORT DRAKE PASSAGE PLANT DIVERSITY COMPONENT WATER SOUTHERN-OCEAN PACIFIC-OCEAN SEAWATER SR Zhang, Y Boer, AM Lunt, DJ Hutchinson, DK Ross, P Flierdt, T Sexton, P Coxall, HK Steinig, S Ladant, J Zhu, J Donnadieu, Y Zhang, Z Chan, W Abe‐Ouchi, A Niezgodzki, I Lohmann, G Knorr, G Poulsen, CJ Huber, M Early Eocene ocean meridional overturning circulation: the roles of atmospheric forcing and strait geometry |
topic_facet |
Science & Technology Physical Sciences Life Sciences & Biomedicine Geosciences Multidisciplinary Oceanography Paleontology Geology DEEP-WATER PRODUCTION STABLE-ISOTOPE RECORD FOSSIL FISH TEETH HEAT-TRANSPORT DRAKE PASSAGE PLANT DIVERSITY COMPONENT WATER SOUTHERN-OCEAN PACIFIC-OCEAN SEAWATER SR |
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 1x (i.e. 280 ppm) to 3x (840ppm) 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. |
author2 |
Natural Environment Research Council (NERC) |
format |
Article in Journal/Newspaper |
author |
Zhang, Y Boer, AM Lunt, DJ Hutchinson, DK Ross, P Flierdt, T Sexton, P Coxall, HK Steinig, S Ladant, J Zhu, J Donnadieu, Y Zhang, Z Chan, W Abe‐Ouchi, A Niezgodzki, I Lohmann, G Knorr, G Poulsen, CJ Huber, M |
author_facet |
Zhang, Y Boer, AM Lunt, DJ Hutchinson, DK Ross, P Flierdt, T Sexton, P Coxall, HK Steinig, S Ladant, J Zhu, J Donnadieu, Y Zhang, Z Chan, W Abe‐Ouchi, A Niezgodzki, I Lohmann, G Knorr, G Poulsen, CJ Huber, M |
author_sort |
Zhang, Y |
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 |
publisher |
American Geophysical Union (AGU) |
publishDate |
2022 |
url |
http://hdl.handle.net/10044/1/95076 https://doi.org/10.1029/2021pa004329 |
geographic |
Drake Passage Pacific Southern Ocean |
geographic_facet |
Drake Passage Pacific Southern Ocean |
genre |
Drake Passage North Atlantic Southern Ocean |
genre_facet |
Drake Passage North Atlantic Southern Ocean |
op_source |
22 1 |
op_relation |
Paleoceanography and Paleoclimatology 2572-4517 http://hdl.handle.net/10044/1/95076 doi:10.1029/2021pa004329 NE/P019080/1 |
op_rights |
© 2022. American Geophysical Union. All Rights Reserved. This is the accepted version of the following article: Zhang, Y., de Boer, A. M., Lunt, D. J., Hutchinson, D. K., Ross, P., van de Flierdt, T., et al. (2022). Early Eocene ocean meridional overturning circulation: The roles of atmospheric forcing and strait geometry. Paleoceanography and Paleoclimatology, 37, e2021PA004329, which has been published in final form at https://doi.org/10.1029/2021PA004329 |
op_doi |
https://doi.org/10.1029/2021pa004329 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
3 |
_version_ |
1766398232734203904 |