Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways
The Eocene–Oligocene Transition (∼33.9 Ma) marks the largest step transformation within the Cenozoic cooling trend and is characterized by a sudden growth of the Antarctic ice sheets, cooling of the interior ocean, and the establishment of strong meridional temperature gradients. Here we examine the...
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ftpubmed:oai:pubmedcentral.nih.gov:9169914 2023-05-15T13:40:22+02:00 Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways Straume, Eivind O. Nummelin, Aleksi Gaina, Carmen Nisancioglu, Kerim H. 2022-04-21 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9169914/ http://www.ncbi.nlm.nih.gov/pubmed/35446685 https://doi.org/10.1073/pnas.2115346119 en eng National Academy of Sciences http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9169914/ http://www.ncbi.nlm.nih.gov/pubmed/35446685 http://dx.doi.org/10.1073/pnas.2115346119 Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by/4.0/This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0/) . CC-BY Proc Natl Acad Sci U S A Physical Sciences Text 2022 ftpubmed https://doi.org/10.1073/pnas.2115346119 2022-06-12T00:47:02Z The Eocene–Oligocene Transition (∼33.9 Ma) marks the largest step transformation within the Cenozoic cooling trend and is characterized by a sudden growth of the Antarctic ice sheets, cooling of the interior ocean, and the establishment of strong meridional temperature gradients. Here we examine the climatic impact of oceanic gateway changes at the Eocene–Oligocene Transition by implementing detailed paleogeographic reconstructions with realistic paleobathymetric models for the Atlantic–Arctic basins in a state-of-the-art earth system model (the Norwegian Earth System Model [NorESM-F]). We demonstrate that the warm Eocene climate is highly sensitive to depth variations of the Greenland–Scotland Ridge and the proto–Fram Strait as they control the freshwater leakage from the Arctic to the North Atlantic. Our results, and proxy evidence, suggest that changes in these gateways controlled the ocean circulation and played a critical role in the growth of land-based ice sheets, alongside CO(2)-driven global cooling. Specifically, we suggest that a shallow connection between the Arctic and North Atlantic restricted the southward flow of fresh surface waters during the Late Eocene allowing for a North Atlantic overturning circulation. Consequently, the Southern Hemisphere cooled by several degrees paving the way for the glaciation of Antarctica. Shortly after, the connection to the Arctic deepened due to weakening dynamic support from the Iceland Mantle Plume. This weakened the North Atlantic overturning and cooled the Northern Hemisphere, thereby promoting glaciations there. Our study points to a controlling role of the Northeast Atlantic gateways and decreasing atmospheric CO(2) in the onset of glaciations in both hemispheres. Text Antarc* Antarctic Antarctica Arctic Atlantic Arctic Atlantic-Arctic Fram Strait Greenland Greenland-Scotland Ridge Iceland North Atlantic Northeast Atlantic PubMed Central (PMC) Antarctic Arctic Greenland The Antarctic Proceedings of the National Academy of Sciences 119 17 |
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English |
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Physical Sciences |
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Physical Sciences Straume, Eivind O. Nummelin, Aleksi Gaina, Carmen Nisancioglu, Kerim H. Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
topic_facet |
Physical Sciences |
description |
The Eocene–Oligocene Transition (∼33.9 Ma) marks the largest step transformation within the Cenozoic cooling trend and is characterized by a sudden growth of the Antarctic ice sheets, cooling of the interior ocean, and the establishment of strong meridional temperature gradients. Here we examine the climatic impact of oceanic gateway changes at the Eocene–Oligocene Transition by implementing detailed paleogeographic reconstructions with realistic paleobathymetric models for the Atlantic–Arctic basins in a state-of-the-art earth system model (the Norwegian Earth System Model [NorESM-F]). We demonstrate that the warm Eocene climate is highly sensitive to depth variations of the Greenland–Scotland Ridge and the proto–Fram Strait as they control the freshwater leakage from the Arctic to the North Atlantic. Our results, and proxy evidence, suggest that changes in these gateways controlled the ocean circulation and played a critical role in the growth of land-based ice sheets, alongside CO(2)-driven global cooling. Specifically, we suggest that a shallow connection between the Arctic and North Atlantic restricted the southward flow of fresh surface waters during the Late Eocene allowing for a North Atlantic overturning circulation. Consequently, the Southern Hemisphere cooled by several degrees paving the way for the glaciation of Antarctica. Shortly after, the connection to the Arctic deepened due to weakening dynamic support from the Iceland Mantle Plume. This weakened the North Atlantic overturning and cooled the Northern Hemisphere, thereby promoting glaciations there. Our study points to a controlling role of the Northeast Atlantic gateways and decreasing atmospheric CO(2) in the onset of glaciations in both hemispheres. |
format |
Text |
author |
Straume, Eivind O. Nummelin, Aleksi Gaina, Carmen Nisancioglu, Kerim H. |
author_facet |
Straume, Eivind O. Nummelin, Aleksi Gaina, Carmen Nisancioglu, Kerim H. |
author_sort |
Straume, Eivind O. |
title |
Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
title_short |
Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
title_full |
Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
title_fullStr |
Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
title_full_unstemmed |
Climate transition at the Eocene–Oligocene influenced by bathymetric changes to the Atlantic–Arctic oceanic gateways |
title_sort |
climate transition at the eocene–oligocene influenced by bathymetric changes to the atlantic–arctic oceanic gateways |
publisher |
National Academy of Sciences |
publishDate |
2022 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9169914/ http://www.ncbi.nlm.nih.gov/pubmed/35446685 https://doi.org/10.1073/pnas.2115346119 |
geographic |
Antarctic Arctic Greenland The Antarctic |
geographic_facet |
Antarctic Arctic Greenland The Antarctic |
genre |
Antarc* Antarctic Antarctica Arctic Atlantic Arctic Atlantic-Arctic Fram Strait Greenland Greenland-Scotland Ridge Iceland North Atlantic Northeast Atlantic |
genre_facet |
Antarc* Antarctic Antarctica Arctic Atlantic Arctic Atlantic-Arctic Fram Strait Greenland Greenland-Scotland Ridge Iceland North Atlantic Northeast Atlantic |
op_source |
Proc Natl Acad Sci U S A |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9169914/ http://www.ncbi.nlm.nih.gov/pubmed/35446685 http://dx.doi.org/10.1073/pnas.2115346119 |
op_rights |
Copyright © 2022 the Author(s). Published by PNAS. https://creativecommons.org/licenses/by/4.0/This open access article is distributed under Creative Commons Attribution License 4.0 (CC BY) (https://creativecommons.org/licenses/by/4.0/) . |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1073/pnas.2115346119 |
container_title |
Proceedings of the National Academy of Sciences |
container_volume |
119 |
container_issue |
17 |
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1766132931407904768 |