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...
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ftncar:oai:drupal-site.org:articles_25288 2024-04-28T08:31:05+00:00 Early Eocene ocean meridional overturning circulation: The roles of atmospheric forcing and strait geometry Zhang, Yurui (author) Boer, Agatha M. (author) Lunt, Daniel J. (author) Hutchinson, David K. (author) Ross, Phoebe (author) Flierdt, Tina (author) Sexton, Philip (author) Coxall, Helen K. (author) Steinig, Sebastian (author) Ladant, Jean‐Baptiste (author) Zhu, Jiang (author) Donnadieu, Yannick (author) Zhang, Zhongshi (author) Chan, Wing‐Le (author) Abe‐Ouchi, Ayako (author) Niezgodzki, Igor (author) Lohmann, Gerrit (author) Knorr, Gregor (author) Poulsen, Christopher J. (author) Huber, Matt (author) 2022-03-05 https://doi.org/10.1029/2021PA004329 en eng Paleoceanography and Paleoclimatology--Paleoceanog and Paleoclimatol--2572-4517--2572-4525 articles:25288 doi:10.1029/2021PA004329 ark:/85065/d74m985j Copyright 2022 American Geophysical Union. article Text 2022 ftncar https://doi.org/10.1029/2021PA004329 2024-04-04T17:33:50Z 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 (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. 1852977 Article in Journal/Newspaper North Atlantic Southern Ocean OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Paleoceanography and Paleoclimatology 37 3 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
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 1x (i.e., 280 ppm) to 3x (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. 1852977 |
author2 |
Zhang, Yurui (author) Boer, Agatha M. (author) Lunt, Daniel J. (author) Hutchinson, David K. (author) Ross, Phoebe (author) Flierdt, Tina (author) Sexton, Philip (author) Coxall, Helen K. (author) Steinig, Sebastian (author) Ladant, Jean‐Baptiste (author) Zhu, Jiang (author) Donnadieu, Yannick (author) Zhang, Zhongshi (author) Chan, Wing‐Le (author) Abe‐Ouchi, Ayako (author) Niezgodzki, Igor (author) Lohmann, Gerrit (author) Knorr, Gregor (author) Poulsen, Christopher J. (author) Huber, Matt (author) |
format |
Article in Journal/Newspaper |
title |
Early Eocene ocean meridional overturning circulation: The roles of atmospheric forcing and strait geometry |
spellingShingle |
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://doi.org/10.1029/2021PA004329 |
genre |
North Atlantic Southern Ocean |
genre_facet |
North Atlantic Southern Ocean |
op_relation |
Paleoceanography and Paleoclimatology--Paleoceanog and Paleoclimatol--2572-4517--2572-4525 articles:25288 doi:10.1029/2021PA004329 ark:/85065/d74m985j |
op_rights |
Copyright 2022 American Geophysical Union. |
op_doi |
https://doi.org/10.1029/2021PA004329 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
37 |
container_issue |
3 |
_version_ |
1797588726486925312 |