Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates
A major tipping point of Earth's history occurred during the mid-Pliocene: the onset of major Northern-Hemisphere Glaciation (NHG) and of pronounced, Quaternary-style cycles of glacial-to-interglacial climates, that contrast with more uniform climates over most of the preceding Cenozoic and con...
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ftdoajarticles:oai:doaj.org/article:2437882897484155899267ee2589ae4b 2023-05-15T13:11:51+02:00 Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates M. Sarnthein G. Bartoli M. Prange A. Schmittner B. Schneider M. Weinelt N. Andersen D. Garbe-Schönberg 2009-06-01T00:00:00Z https://doaj.org/article/2437882897484155899267ee2589ae4b EN eng Copernicus Publications http://www.clim-past.net/5/269/2009/cp-5-269-2009.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/2437882897484155899267ee2589ae4b Climate of the Past, Vol 5, Iss 2, Pp 269-283 (2009) Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 article 2009 ftdoajarticles 2022-12-31T08:38:33Z A major tipping point of Earth's history occurred during the mid-Pliocene: the onset of major Northern-Hemisphere Glaciation (NHG) and of pronounced, Quaternary-style cycles of glacial-to-interglacial climates, that contrast with more uniform climates over most of the preceding Cenozoic and continue until today (Zachos et al., 2001). The severe deterioration of climate occurred in three steps between 3.2 Ma (warm MIS K3) and 2.7 Ma (glacial MIS G6/4) (Lisiecki and Raymo, 2005). Various models (sensu Driscoll and Haug, 1998) and paleoceanographic records (intercalibrated using orbital age control) suggest clear linkages between the onset of NHG and the three steps in the final closure of the Central American Seaways (CAS), deduced from rising salinity differences between Caribbean and the East Pacific. Each closing event led to an enhanced North Atlantic meridional overturning circulation and this strengthened the poleward transport of salt and heat (warmings of +2–3°C) (Bartoli et al., 2005). Also, the closing resulted in a slight rise in the poleward atmospheric moisture transport to northwestern Eurasia (Lunt et al., 2007), which probably led to an enhanced precipitation and fluvial run-off, lower sea surface salinity (SSS), and an increased sea-ice cover in the Arctic Ocean, hence promoting albedo and the build-up of continental ice sheets. Most important, new evidence shows that the closing of the CAS led to greater steric height of the North Pacific and thus doubled the low-saline Arctic Throughflow from the Bering Strait to the East Greenland Current (EGC). Accordingly, Labrador Sea IODP Site 1307 displays an abrupt but irreversible EGC cooling of 6°C and freshening by ~2 psu from 3.25/3.16–3.00 Ma, right after the first but still reversible attempt of closing the CAS. Article in Journal/Newspaper albedo Arctic Arctic Ocean Bering Strait East Greenland east greenland current Greenland Labrador Sea North Atlantic Sea ice Directory of Open Access Journals: DOAJ Articles Arctic Arctic Ocean Bering Strait Greenland Pacific Haug ENVELOPE(15.188,15.188,67.918,67.918) |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
spellingShingle |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 M. Sarnthein G. Bartoli M. Prange A. Schmittner B. Schneider M. Weinelt N. Andersen D. Garbe-Schönberg Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
topic_facet |
Environmental pollution TD172-193.5 Environmental protection TD169-171.8 Environmental sciences GE1-350 |
description |
A major tipping point of Earth's history occurred during the mid-Pliocene: the onset of major Northern-Hemisphere Glaciation (NHG) and of pronounced, Quaternary-style cycles of glacial-to-interglacial climates, that contrast with more uniform climates over most of the preceding Cenozoic and continue until today (Zachos et al., 2001). The severe deterioration of climate occurred in three steps between 3.2 Ma (warm MIS K3) and 2.7 Ma (glacial MIS G6/4) (Lisiecki and Raymo, 2005). Various models (sensu Driscoll and Haug, 1998) and paleoceanographic records (intercalibrated using orbital age control) suggest clear linkages between the onset of NHG and the three steps in the final closure of the Central American Seaways (CAS), deduced from rising salinity differences between Caribbean and the East Pacific. Each closing event led to an enhanced North Atlantic meridional overturning circulation and this strengthened the poleward transport of salt and heat (warmings of +2–3°C) (Bartoli et al., 2005). Also, the closing resulted in a slight rise in the poleward atmospheric moisture transport to northwestern Eurasia (Lunt et al., 2007), which probably led to an enhanced precipitation and fluvial run-off, lower sea surface salinity (SSS), and an increased sea-ice cover in the Arctic Ocean, hence promoting albedo and the build-up of continental ice sheets. Most important, new evidence shows that the closing of the CAS led to greater steric height of the North Pacific and thus doubled the low-saline Arctic Throughflow from the Bering Strait to the East Greenland Current (EGC). Accordingly, Labrador Sea IODP Site 1307 displays an abrupt but irreversible EGC cooling of 6°C and freshening by ~2 psu from 3.25/3.16–3.00 Ma, right after the first but still reversible attempt of closing the CAS. |
format |
Article in Journal/Newspaper |
author |
M. Sarnthein G. Bartoli M. Prange A. Schmittner B. Schneider M. Weinelt N. Andersen D. Garbe-Schönberg |
author_facet |
M. Sarnthein G. Bartoli M. Prange A. Schmittner B. Schneider M. Weinelt N. Andersen D. Garbe-Schönberg |
author_sort |
M. Sarnthein |
title |
Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
title_short |
Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
title_full |
Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
title_fullStr |
Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
title_full_unstemmed |
Mid-Pliocene shifts in ocean overturning circulation and the onset of Quaternary-style climates |
title_sort |
mid-pliocene shifts in ocean overturning circulation and the onset of quaternary-style climates |
publisher |
Copernicus Publications |
publishDate |
2009 |
url |
https://doaj.org/article/2437882897484155899267ee2589ae4b |
long_lat |
ENVELOPE(15.188,15.188,67.918,67.918) |
geographic |
Arctic Arctic Ocean Bering Strait Greenland Pacific Haug |
geographic_facet |
Arctic Arctic Ocean Bering Strait Greenland Pacific Haug |
genre |
albedo Arctic Arctic Ocean Bering Strait East Greenland east greenland current Greenland Labrador Sea North Atlantic Sea ice |
genre_facet |
albedo Arctic Arctic Ocean Bering Strait East Greenland east greenland current Greenland Labrador Sea North Atlantic Sea ice |
op_source |
Climate of the Past, Vol 5, Iss 2, Pp 269-283 (2009) |
op_relation |
http://www.clim-past.net/5/269/2009/cp-5-269-2009.pdf https://doaj.org/toc/1814-9324 https://doaj.org/toc/1814-9332 1814-9324 1814-9332 https://doaj.org/article/2437882897484155899267ee2589ae4b |
_version_ |
1766249239593091072 |