Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene
An essential element of modern ocean circulation and climate is the Atlantic meridional overturning circulation (AMOC), which includes deep-water formation in the subarctic North Atlantic. However, a comparable overturning circulation is absent in the Pacific, the world’s largest ocean, where relati...
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ftdatacite:10.7892/boris.105414 2023-05-15T17:34:43+02:00 Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene Burls, Natalie J. Fedorov, Alexey V. Sigman, Daniel Jaccard, Samuel Tiedemann, Ralf Haug, Gerald 2017 application/pdf https://dx.doi.org/10.7892/boris.105414 https://boris.unibe.ch/105414/ en eng American Association for the Advancement of Science info:eu-repo/semantics/openAccess 550 Earth sciences & geology Text article-journal ScholarlyArticle 2017 ftdatacite https://doi.org/10.7892/boris.105414 2021-11-05T12:55:41Z An essential element of modern ocean circulation and climate is the Atlantic meridional overturning circulation (AMOC), which includes deep-water formation in the subarctic North Atlantic. However, a comparable overturning circulation is absent in the Pacific, the world’s largest ocean, where relatively fresh surface waters inhibit North Pacific deep convection. We present complementary measurement and modeling evidence that the warm, ~400–ppmv (parts per million by volume) CO2 world of the Pliocene supported subarctic North Pacific deep-water formation and a Pacific meridional overturning circulation (PMOC) cell. In Pliocene subarctic North Pacific sediments, we report orbitally paced maxima in calcium carbonate accumulation rate, with accompanying pigment and total organic carbon measurements supporting deep-ocean ventilation-driven preservation as their cause. Together with high accumulation rates of biogenic opal, these findings require vigorous bidirectional communication between surface waters and interior waters down to ~3 km in the western subarctic North Pacific, implying deep convection. Redox- sensitive trace metal data provide further evidence of higher Pliocene deep-ocean ventilation before the 2.73-Ma (million years) transition. This observational analysis is supported by climate modeling results, demonstrating that atmospheric moisture transport changes, in response to the reduced meridional sea surface temperature gradients of the Pliocene, were capable of eroding the halocline, leading to deep-water formation in the western subarctic Pacific and a strong PMOC. This second Northern Hemisphere overturning cell has important implica- tions for heat transport, the ocean/atmosphere cycle of carbon, and potentially the equilibrium response of the Pacific to global warming. Text North Atlantic Subarctic DataCite Metadata Store (German National Library of Science and Technology) Pacific |
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550 Earth sciences & geology |
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550 Earth sciences & geology Burls, Natalie J. Fedorov, Alexey V. Sigman, Daniel Jaccard, Samuel Tiedemann, Ralf Haug, Gerald Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
topic_facet |
550 Earth sciences & geology |
description |
An essential element of modern ocean circulation and climate is the Atlantic meridional overturning circulation (AMOC), which includes deep-water formation in the subarctic North Atlantic. However, a comparable overturning circulation is absent in the Pacific, the world’s largest ocean, where relatively fresh surface waters inhibit North Pacific deep convection. We present complementary measurement and modeling evidence that the warm, ~400–ppmv (parts per million by volume) CO2 world of the Pliocene supported subarctic North Pacific deep-water formation and a Pacific meridional overturning circulation (PMOC) cell. In Pliocene subarctic North Pacific sediments, we report orbitally paced maxima in calcium carbonate accumulation rate, with accompanying pigment and total organic carbon measurements supporting deep-ocean ventilation-driven preservation as their cause. Together with high accumulation rates of biogenic opal, these findings require vigorous bidirectional communication between surface waters and interior waters down to ~3 km in the western subarctic North Pacific, implying deep convection. Redox- sensitive trace metal data provide further evidence of higher Pliocene deep-ocean ventilation before the 2.73-Ma (million years) transition. This observational analysis is supported by climate modeling results, demonstrating that atmospheric moisture transport changes, in response to the reduced meridional sea surface temperature gradients of the Pliocene, were capable of eroding the halocline, leading to deep-water formation in the western subarctic Pacific and a strong PMOC. This second Northern Hemisphere overturning cell has important implica- tions for heat transport, the ocean/atmosphere cycle of carbon, and potentially the equilibrium response of the Pacific to global warming. |
format |
Text |
author |
Burls, Natalie J. Fedorov, Alexey V. Sigman, Daniel Jaccard, Samuel Tiedemann, Ralf Haug, Gerald |
author_facet |
Burls, Natalie J. Fedorov, Alexey V. Sigman, Daniel Jaccard, Samuel Tiedemann, Ralf Haug, Gerald |
author_sort |
Burls, Natalie J. |
title |
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
title_short |
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
title_full |
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
title_fullStr |
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
title_full_unstemmed |
Active Pacific meridional overturning circulation (PMOC) during the warm Pliocene |
title_sort |
active pacific meridional overturning circulation (pmoc) during the warm pliocene |
publisher |
American Association for the Advancement of Science |
publishDate |
2017 |
url |
https://dx.doi.org/10.7892/boris.105414 https://boris.unibe.ch/105414/ |
geographic |
Pacific |
geographic_facet |
Pacific |
genre |
North Atlantic Subarctic |
genre_facet |
North Atlantic Subarctic |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.7892/boris.105414 |
_version_ |
1766133632996474880 |