Temperature gradients across the Pacific Ocean during the Middle Miocene
Sea surface temperatures (SSTs) of the tropical Pacific Ocean exert powerful controls on regional and global climates. Previous studies have suggested that during warm climate phases, the east-west temperature gradient collapsed. To date, there has been no high-resolution reconstruction of sea surfa...
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Online Access: | http://nora.nerc.ac.uk/id/eprint/530777/ https://nora.nerc.ac.uk/id/eprint/530777/1/2020PA003924.pdf https://doi.org/10.1029/2020PA003924 |
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ftnerc:oai:nora.nerc.ac.uk:530777 2023-05-15T13:41:45+02:00 Temperature gradients across the Pacific Ocean during the Middle Miocene Fox, Lyndsey R. Wade, Bridget S. Holbourn, Ann Leng, Melanie J. Bhatia, Rehemat 2021-06 text http://nora.nerc.ac.uk/id/eprint/530777/ https://nora.nerc.ac.uk/id/eprint/530777/1/2020PA003924.pdf https://doi.org/10.1029/2020PA003924 en eng Wiley https://nora.nerc.ac.uk/id/eprint/530777/1/2020PA003924.pdf Fox, Lyndsey R.; Wade, Bridget S.; Holbourn, Ann; Leng, Melanie J. orcid:0000-0003-1115-5166 Bhatia, Rehemat. 2021 Temperature gradients across the Pacific Ocean during the Middle Miocene. Paleoceanography and Paleoclimatology, 36 (6), e2020PA003924. https://doi.org/10.1029/2020PA003924 <https://doi.org/10.1029/2020PA003924> cc_by_4 CC-BY Publication - Article PeerReviewed 2021 ftnerc https://doi.org/10.1029/2020PA003924 2023-02-04T19:52:24Z Sea surface temperatures (SSTs) of the tropical Pacific Ocean exert powerful controls on regional and global climates. Previous studies have suggested that during warm climate phases, the east-west temperature gradient collapsed. To date, there has been no high-resolution reconstruction of sea surface conditions in both the east and west Pacific Ocean during the Miocene Climate Optimum (MCO) and across the middle Miocene climate transition (MMCT); therefore, our understanding of the mean oceanographic state during this major global climatic shift is limited. Here, we present new SST reconstructions for the eastern Pacific Ocean (15.5–13.3 Ma) which show a clear east-west temperature gradient of ∼4°C during the warmest interval of the Neogene, implying that the oceanographic processes that produce the modern gradient were present and active. There is no shift in the east-west gradient across the MMCT indicating that the gradient was not impacted by global cooling and ice growth. We find a 2°C sea surface cooling in the eastern equatorial Pacific, that lags the benthic foraminiferal δ18O positive shift by 150 kyr, indicating that tropical temperature did not decrease synchronously with the expansion of the Antarctic ice sheet. Reconstructed variations in the δ18O composition of seawater, determined by combining our Mg/Ca and δ18O records, reveal a freshening in the eastern Pacific Ocean after 13.8 Ma, suggesting changes in the hydrological cycle and in tropical fronts in response to the new icehouse regime. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Natural Environment Research Council: NERC Open Research Archive Antarctic The Antarctic Pacific Paleoceanography and Paleoclimatology 36 6 |
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Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
English |
description |
Sea surface temperatures (SSTs) of the tropical Pacific Ocean exert powerful controls on regional and global climates. Previous studies have suggested that during warm climate phases, the east-west temperature gradient collapsed. To date, there has been no high-resolution reconstruction of sea surface conditions in both the east and west Pacific Ocean during the Miocene Climate Optimum (MCO) and across the middle Miocene climate transition (MMCT); therefore, our understanding of the mean oceanographic state during this major global climatic shift is limited. Here, we present new SST reconstructions for the eastern Pacific Ocean (15.5–13.3 Ma) which show a clear east-west temperature gradient of ∼4°C during the warmest interval of the Neogene, implying that the oceanographic processes that produce the modern gradient were present and active. There is no shift in the east-west gradient across the MMCT indicating that the gradient was not impacted by global cooling and ice growth. We find a 2°C sea surface cooling in the eastern equatorial Pacific, that lags the benthic foraminiferal δ18O positive shift by 150 kyr, indicating that tropical temperature did not decrease synchronously with the expansion of the Antarctic ice sheet. Reconstructed variations in the δ18O composition of seawater, determined by combining our Mg/Ca and δ18O records, reveal a freshening in the eastern Pacific Ocean after 13.8 Ma, suggesting changes in the hydrological cycle and in tropical fronts in response to the new icehouse regime. |
format |
Article in Journal/Newspaper |
author |
Fox, Lyndsey R. Wade, Bridget S. Holbourn, Ann Leng, Melanie J. Bhatia, Rehemat |
spellingShingle |
Fox, Lyndsey R. Wade, Bridget S. Holbourn, Ann Leng, Melanie J. Bhatia, Rehemat Temperature gradients across the Pacific Ocean during the Middle Miocene |
author_facet |
Fox, Lyndsey R. Wade, Bridget S. Holbourn, Ann Leng, Melanie J. Bhatia, Rehemat |
author_sort |
Fox, Lyndsey R. |
title |
Temperature gradients across the Pacific Ocean during the Middle Miocene |
title_short |
Temperature gradients across the Pacific Ocean during the Middle Miocene |
title_full |
Temperature gradients across the Pacific Ocean during the Middle Miocene |
title_fullStr |
Temperature gradients across the Pacific Ocean during the Middle Miocene |
title_full_unstemmed |
Temperature gradients across the Pacific Ocean during the Middle Miocene |
title_sort |
temperature gradients across the pacific ocean during the middle miocene |
publisher |
Wiley |
publishDate |
2021 |
url |
http://nora.nerc.ac.uk/id/eprint/530777/ https://nora.nerc.ac.uk/id/eprint/530777/1/2020PA003924.pdf https://doi.org/10.1029/2020PA003924 |
geographic |
Antarctic The Antarctic Pacific |
geographic_facet |
Antarctic The Antarctic Pacific |
genre |
Antarc* Antarctic Ice Sheet |
genre_facet |
Antarc* Antarctic Ice Sheet |
op_relation |
https://nora.nerc.ac.uk/id/eprint/530777/1/2020PA003924.pdf Fox, Lyndsey R.; Wade, Bridget S.; Holbourn, Ann; Leng, Melanie J. orcid:0000-0003-1115-5166 Bhatia, Rehemat. 2021 Temperature gradients across the Pacific Ocean during the Middle Miocene. Paleoceanography and Paleoclimatology, 36 (6), e2020PA003924. https://doi.org/10.1029/2020PA003924 <https://doi.org/10.1029/2020PA003924> |
op_rights |
cc_by_4 |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1029/2020PA003924 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
36 |
container_issue |
6 |
_version_ |
1766157532628254720 |