Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2
Abstract. The mid-Pliocene warm period (3.264–3.025 Ma) is the most recent geological period in which the atmospheric CO2 concentration was approximately equal to the concentration we measure today (ca. 400 ppm). Sea surface temperature (SST) proxies indicate above-average warming over the North Atl...
Published in: | Climate of the Past |
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Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Copernicus Publications under license by EGU – European Geosciences Union GmbH
2023
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Online Access: | http://hdl.handle.net/10852/102658 https://doi.org/10.5194/cp-19-61-2023 |
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Universitet i Oslo: Digitale utgivelser ved UiO (DUO) |
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English |
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Abstract. The mid-Pliocene warm period (3.264–3.025 Ma) is the most recent geological period in which the atmospheric CO2 concentration was approximately equal to the concentration we measure today (ca. 400 ppm). Sea surface temperature (SST) proxies indicate above-average warming over the North Atlantic in the mid-Pliocene with respect to the pre-industrial period, which may be linked to an intensified Atlantic Meridional Overturning Circulation (AMOC). Earlier results from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) show that the ensemble simulates a stronger AMOC in the mid-Pliocene than in the pre-industrial. However, no consistent relationship between the stronger mid-Pliocene AMOC and either the Atlantic northward ocean heat transport (OHT) or average North Atlantic SSTs has been found. In this study, we look further into the drivers and consequences of a stronger AMOC in mid-Pliocene compared to pre-industrial simulations in PlioMIP2. We find that all model simulations with a closed Bering Strait and Canadian Archipelago show reduced freshwater transport from the Arctic Ocean into the North Atlantic. This contributes to an increase in salinity in the subpolar North Atlantic and Labrador Sea that can be linked to the stronger AMOC in the mid-Pliocene. To investigate the dynamics behind the ensemble's variable response of the total Atlantic OHT to the stronger AMOC, we separate the Atlantic OHT into two components associated with either the overturning circulation or the wind-driven gyre circulation. While the ensemble mean of the overturning component is increased significantly in magnitude in the mid-Pliocene, it is partly compensated by a reduction in the gyre component in the northern subtropical gyre region. This indicates that the lack of relationship between the total OHT and AMOC is due to changes in OHT by the subtropical gyre. The overturning and gyre components should therefore be considered separately to gain a more complete understanding of the OHT response to a stronger ... |
format |
Article in Journal/Newspaper |
author |
Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi |
spellingShingle |
Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
author_facet |
Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi |
author_sort |
Weiffenbach, Julia E. |
title |
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
title_short |
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
title_full |
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
title_fullStr |
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
title_full_unstemmed |
Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 |
title_sort |
unraveling the mechanisms and implications of a stronger mid-pliocene atlantic meridional overturning circulation (amoc) in pliomip2 |
publisher |
Copernicus Publications under license by EGU – European Geosciences Union GmbH |
publishDate |
2023 |
url |
http://hdl.handle.net/10852/102658 https://doi.org/10.5194/cp-19-61-2023 |
geographic |
Arctic Arctic Ocean Bering Strait |
geographic_facet |
Arctic Arctic Ocean Bering Strait |
genre |
Arctic Arctic Ocean Bering Strait Canadian Archipelago Labrador Sea North Atlantic |
genre_facet |
Arctic Arctic Ocean Bering Strait Canadian Archipelago Labrador Sea North Atlantic |
op_source |
1814-9324 |
op_relation |
Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi . Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2. Climate of the Past. 2023, 19(1), 61-85 http://hdl.handle.net/10852/102658 2129324 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Climate of the Past&rft.volume=19&rft.spage=61&rft.date=2023 Climate of the Past 19 1 61 85 https://doi.org/10.5194/cp-19-61-2023 |
op_rights |
Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ |
op_doi |
https://doi.org/10.5194/cp-19-61-2023 |
container_title |
Climate of the Past |
container_volume |
19 |
container_issue |
1 |
container_start_page |
61 |
op_container_end_page |
85 |
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1772812895858458624 |
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ftoslouniv:oai:www.duo.uio.no:10852/102658 2023-07-30T04:02:10+02:00 Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 ENEngelskEnglishUnraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2 Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi 2023-02-26T13:12:43Z http://hdl.handle.net/10852/102658 https://doi.org/10.5194/cp-19-61-2023 EN eng Copernicus Publications under license by EGU – European Geosciences Union GmbH Weiffenbach, Julia E. Baatsen, Michiel L. J. Dijkstra, Henk A. Von Der Heydt, Anna S. Abe-Ouchi, Ayako Brady, Esther C. Chan, Wing-Le Chandan, Deepak Chandler, Mark A. Contoux, Camille Feng, Ran Guo, Chuncheng Han, Zixuan Haywood, Alan M. Li, Qiang Li, Xiangyu Lohmann, Gerrit Lunt, Daniel J. Nisancioglu, Kerim Hestnes Otto-Bliesner, Bette L. Peltier, W. Richard Ramstein, Gilles Sohl, Linda E. Stepanek, Christian Tan, Ning Tindall, Julia C. Williams, Charles J. R. Zhang, Qiong Zhang, Zhongshi . Unraveling the mechanisms and implications of a stronger mid-Pliocene Atlantic Meridional Overturning Circulation (AMOC) in PlioMIP2. Climate of the Past. 2023, 19(1), 61-85 http://hdl.handle.net/10852/102658 2129324 info:ofi/fmt:kev:mtx:ctx&ctx_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.jtitle=Climate of the Past&rft.volume=19&rft.spage=61&rft.date=2023 Climate of the Past 19 1 61 85 https://doi.org/10.5194/cp-19-61-2023 Attribution 4.0 International https://creativecommons.org/licenses/by/4.0/ 1814-9324 Journal article Tidsskriftartikkel Peer reviewed PublishedVersion 2023 ftoslouniv https://doi.org/10.5194/cp-19-61-2023 2023-07-12T22:38:52Z Abstract. The mid-Pliocene warm period (3.264–3.025 Ma) is the most recent geological period in which the atmospheric CO2 concentration was approximately equal to the concentration we measure today (ca. 400 ppm). Sea surface temperature (SST) proxies indicate above-average warming over the North Atlantic in the mid-Pliocene with respect to the pre-industrial period, which may be linked to an intensified Atlantic Meridional Overturning Circulation (AMOC). Earlier results from the Pliocene Model Intercomparison Project Phase 2 (PlioMIP2) show that the ensemble simulates a stronger AMOC in the mid-Pliocene than in the pre-industrial. However, no consistent relationship between the stronger mid-Pliocene AMOC and either the Atlantic northward ocean heat transport (OHT) or average North Atlantic SSTs has been found. In this study, we look further into the drivers and consequences of a stronger AMOC in mid-Pliocene compared to pre-industrial simulations in PlioMIP2. We find that all model simulations with a closed Bering Strait and Canadian Archipelago show reduced freshwater transport from the Arctic Ocean into the North Atlantic. This contributes to an increase in salinity in the subpolar North Atlantic and Labrador Sea that can be linked to the stronger AMOC in the mid-Pliocene. To investigate the dynamics behind the ensemble's variable response of the total Atlantic OHT to the stronger AMOC, we separate the Atlantic OHT into two components associated with either the overturning circulation or the wind-driven gyre circulation. While the ensemble mean of the overturning component is increased significantly in magnitude in the mid-Pliocene, it is partly compensated by a reduction in the gyre component in the northern subtropical gyre region. This indicates that the lack of relationship between the total OHT and AMOC is due to changes in OHT by the subtropical gyre. The overturning and gyre components should therefore be considered separately to gain a more complete understanding of the OHT response to a stronger ... Article in Journal/Newspaper Arctic Arctic Ocean Bering Strait Canadian Archipelago Labrador Sea North Atlantic Universitet i Oslo: Digitale utgivelser ved UiO (DUO) Arctic Arctic Ocean Bering Strait Climate of the Past 19 1 61 85 |