Highly stratified mid-Pliocene Southern Ocean in PlioMIP2
During the mid-Pliocene warm period (mPWP; 3.264–3.025 Ma), atmospheric CO2 concentrations were approximately 400 ppm, and the Antarctic Ice Sheet was substantially reduced compared to today. Antarctica is surrounded by the Southern Ocean, which plays a crucial role in the global oceanic circulation...
Published in: | Climate of the Past |
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Copernicus GmbH
2024
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Online Access: | https://epic.awi.de/id/eprint/58723/ https://epic.awi.de/id/eprint/58723/1/cp-20-1067-2024.pdf https://doi.org/10.5194/cp-20-1067-2024 https://hdl.handle.net/10013/epic.f9dbf9c9-4c8a-4bef-8155-c0f92dfeebf2 |
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ftawi:oai:epic.awi.de:58723 2024-06-02T07:57:48+00:00 Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 Weiffenbach, Julia E Dijkstra, Henk A von der Heydt, Anna S Abe-Ouchi, Ayako Chan, Wing-Le Chandan, Deepak Feng, Ran Haywood, Alan M Hunter, Stephen J Li, Xiangyu Otto-Bliesner, Bette L Peltier, W Richard Stepanek, Christian Tan, Ning Tindall, Julia C Zhang, Zhongshi 2024-05-02 application/pdf https://epic.awi.de/id/eprint/58723/ https://epic.awi.de/id/eprint/58723/1/cp-20-1067-2024.pdf https://doi.org/10.5194/cp-20-1067-2024 https://hdl.handle.net/10013/epic.f9dbf9c9-4c8a-4bef-8155-c0f92dfeebf2 unknown Copernicus GmbH https://epic.awi.de/id/eprint/58723/1/cp-20-1067-2024.pdf Weiffenbach, J. E. , Dijkstra, H. A. , von der Heydt, A. S. , Abe-Ouchi, A. , Chan, W. L. , Chandan, D. , Feng, R. , Haywood, A. M. , Hunter, S. J. , Li, X. , Otto-Bliesner, B. L. , Peltier, W. R. , Stepanek, C. orcid:0000-0002-3912-6271 , Tan, N. , Tindall, J. C. and Zhang, Z. (2024) Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 , Climate of the Past, 20 (4), pp. 1067-1086 . doi:10.5194/cp-20-1067-2024 <https://doi.org/10.5194/cp-20-1067-2024> , hdl:10013/epic.f9dbf9c9-4c8a-4bef-8155-c0f92dfeebf2 EPIC3Climate of the Past, Copernicus GmbH, 20(4), pp. 1067-1086, ISSN: 1814-9332 Article isiRev 2024 ftawi https://doi.org/10.5194/cp-20-1067-2024 2024-05-07T23:37:52Z During the mid-Pliocene warm period (mPWP; 3.264–3.025 Ma), atmospheric CO2 concentrations were approximately 400 ppm, and the Antarctic Ice Sheet was substantially reduced compared to today. Antarctica is surrounded by the Southern Ocean, which plays a crucial role in the global oceanic circulation and climate regulation. Using results from the Pliocene Model Intercomparison Project (PlioMIP2), we investigate Southern Ocean conditions during the mPWP with respect to the pre-industrial period. We find that the mean sea surface temperature (SST) warming in the Southern Ocean is 2.8 °C, while global mean SST warming is 2.4 °C. The enhanced warming is strongly tied to a dramatic decrease in sea ice cover over the mPWP Southern Ocean. We also see a freshening of the ocean (sub)surface, driven by an increase in precipitation over the Southern Ocean and Antarctica. The warmer and fresher surface leads to a highly stratified Southern Ocean that can be related to weakening of the deep abyssal overturning circulation. Sensitivity simulations show that the decrease in sea ice cover and enhanced warming is largely a consequence of the reduction in the Antarctic Ice Sheet. In addition, the mPWP geographic boundary conditions are responsible for approximately half of the increase in mPWP SST warming, sea ice loss, precipitation, and stratification increase over the Southern Ocean. From these results, we conclude that a strongly reduced Antarctic Ice Sheet during the mPWP has a substantial influence on the state of the Southern Ocean and exacerbates the changes that are induced by a higher CO2 concentration alone. This is relevant for the long-term future of the Southern Ocean, as we expect melting of the western Antarctic Ice Sheet in the future, an effect that is not currently taken into account in future projections by Coupled Model Intercomparison Project (CMIP) ensembles. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Sea ice Southern Ocean Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Antarctic Southern Ocean The Antarctic Climate of the Past 20 4 1067 1086 |
institution |
Open Polar |
collection |
Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
op_collection_id |
ftawi |
language |
unknown |
description |
During the mid-Pliocene warm period (mPWP; 3.264–3.025 Ma), atmospheric CO2 concentrations were approximately 400 ppm, and the Antarctic Ice Sheet was substantially reduced compared to today. Antarctica is surrounded by the Southern Ocean, which plays a crucial role in the global oceanic circulation and climate regulation. Using results from the Pliocene Model Intercomparison Project (PlioMIP2), we investigate Southern Ocean conditions during the mPWP with respect to the pre-industrial period. We find that the mean sea surface temperature (SST) warming in the Southern Ocean is 2.8 °C, while global mean SST warming is 2.4 °C. The enhanced warming is strongly tied to a dramatic decrease in sea ice cover over the mPWP Southern Ocean. We also see a freshening of the ocean (sub)surface, driven by an increase in precipitation over the Southern Ocean and Antarctica. The warmer and fresher surface leads to a highly stratified Southern Ocean that can be related to weakening of the deep abyssal overturning circulation. Sensitivity simulations show that the decrease in sea ice cover and enhanced warming is largely a consequence of the reduction in the Antarctic Ice Sheet. In addition, the mPWP geographic boundary conditions are responsible for approximately half of the increase in mPWP SST warming, sea ice loss, precipitation, and stratification increase over the Southern Ocean. From these results, we conclude that a strongly reduced Antarctic Ice Sheet during the mPWP has a substantial influence on the state of the Southern Ocean and exacerbates the changes that are induced by a higher CO2 concentration alone. This is relevant for the long-term future of the Southern Ocean, as we expect melting of the western Antarctic Ice Sheet in the future, an effect that is not currently taken into account in future projections by Coupled Model Intercomparison Project (CMIP) ensembles. |
format |
Article in Journal/Newspaper |
author |
Weiffenbach, Julia E Dijkstra, Henk A von der Heydt, Anna S Abe-Ouchi, Ayako Chan, Wing-Le Chandan, Deepak Feng, Ran Haywood, Alan M Hunter, Stephen J Li, Xiangyu Otto-Bliesner, Bette L Peltier, W Richard Stepanek, Christian Tan, Ning Tindall, Julia C Zhang, Zhongshi |
spellingShingle |
Weiffenbach, Julia E Dijkstra, Henk A von der Heydt, Anna S Abe-Ouchi, Ayako Chan, Wing-Le Chandan, Deepak Feng, Ran Haywood, Alan M Hunter, Stephen J Li, Xiangyu Otto-Bliesner, Bette L Peltier, W Richard Stepanek, Christian Tan, Ning Tindall, Julia C Zhang, Zhongshi Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
author_facet |
Weiffenbach, Julia E Dijkstra, Henk A von der Heydt, Anna S Abe-Ouchi, Ayako Chan, Wing-Le Chandan, Deepak Feng, Ran Haywood, Alan M Hunter, Stephen J Li, Xiangyu Otto-Bliesner, Bette L Peltier, W Richard Stepanek, Christian Tan, Ning Tindall, Julia C Zhang, Zhongshi |
author_sort |
Weiffenbach, Julia E |
title |
Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
title_short |
Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
title_full |
Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
title_fullStr |
Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
title_full_unstemmed |
Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 |
title_sort |
highly stratified mid-pliocene southern ocean in pliomip2 |
publisher |
Copernicus GmbH |
publishDate |
2024 |
url |
https://epic.awi.de/id/eprint/58723/ https://epic.awi.de/id/eprint/58723/1/cp-20-1067-2024.pdf https://doi.org/10.5194/cp-20-1067-2024 https://hdl.handle.net/10013/epic.f9dbf9c9-4c8a-4bef-8155-c0f92dfeebf2 |
geographic |
Antarctic Southern Ocean The Antarctic |
geographic_facet |
Antarctic Southern Ocean The Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Sea ice Southern Ocean |
op_source |
EPIC3Climate of the Past, Copernicus GmbH, 20(4), pp. 1067-1086, ISSN: 1814-9332 |
op_relation |
https://epic.awi.de/id/eprint/58723/1/cp-20-1067-2024.pdf Weiffenbach, J. E. , Dijkstra, H. A. , von der Heydt, A. S. , Abe-Ouchi, A. , Chan, W. L. , Chandan, D. , Feng, R. , Haywood, A. M. , Hunter, S. J. , Li, X. , Otto-Bliesner, B. L. , Peltier, W. R. , Stepanek, C. orcid:0000-0002-3912-6271 , Tan, N. , Tindall, J. C. and Zhang, Z. (2024) Highly stratified mid-Pliocene Southern Ocean in PlioMIP2 , Climate of the Past, 20 (4), pp. 1067-1086 . doi:10.5194/cp-20-1067-2024 <https://doi.org/10.5194/cp-20-1067-2024> , hdl:10013/epic.f9dbf9c9-4c8a-4bef-8155-c0f92dfeebf2 |
op_doi |
https://doi.org/10.5194/cp-20-1067-2024 |
container_title |
Climate of the Past |
container_volume |
20 |
container_issue |
4 |
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1067 |
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1086 |
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