Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation?
Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the i...
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ftcdlib:oai:escholarship.org/ark:/13030/qt3kx1q270 2023-05-15T14:01:12+02:00 Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? Sun, S Eisenman, I Stewart, AL 2413 - 2423 2018-03-16 application/pdf https://escholarship.org/uc/item/3kx1q270 unknown eScholarship, University of California qt3kx1q270 https://escholarship.org/uc/item/3kx1q270 public Geophysical Research Letters, vol 45, iss 5 Southern Ocean global ocean overturning circulation climate model Last Glacial Maximum Meteorology & Atmospheric Sciences article 2018 ftcdlib 2021-04-16T07:10:28Z Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the influence of Southern Ocean surface forcing on the AMOC depth is investigated using ocean-only simulations from a state-of-the-art climate model with surface forcing specified from the output of previous coupled PI and LGM simulations. In contrast to previous expectations, we find that applying LGM surface forcing in the Southern Ocean and PI surface forcing elsewhere causes the AMOC to shoal only about half as much as when LGM surface forcing is applied globally. We show that this occurs because diapycnal mixing renders the Southern Ocean overturning circulation more diabatic than previously assumed, which diminishes the influence of Southern Ocean surface buoyancy forcing on the depth of the AMOC. Article in Journal/Newspaper Antarc* Antarctic Sea ice Southern Ocean University of California: eScholarship Antarctic Southern Ocean |
institution |
Open Polar |
collection |
University of California: eScholarship |
op_collection_id |
ftcdlib |
language |
unknown |
topic |
Southern Ocean global ocean overturning circulation climate model Last Glacial Maximum Meteorology & Atmospheric Sciences |
spellingShingle |
Southern Ocean global ocean overturning circulation climate model Last Glacial Maximum Meteorology & Atmospheric Sciences Sun, S Eisenman, I Stewart, AL Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
topic_facet |
Southern Ocean global ocean overturning circulation climate model Last Glacial Maximum Meteorology & Atmospheric Sciences |
description |
Paleoclimate proxy data suggest that the Atlantic Meridional Overturning Circulation (AMOC) was shallower at the Last Glacial Maximum (LGM) than its preindustrial (PI) depth. Previous studies have suggested that this shoaling necessarily accompanies Antarctic sea ice expansion at the LGM. Here the influence of Southern Ocean surface forcing on the AMOC depth is investigated using ocean-only simulations from a state-of-the-art climate model with surface forcing specified from the output of previous coupled PI and LGM simulations. In contrast to previous expectations, we find that applying LGM surface forcing in the Southern Ocean and PI surface forcing elsewhere causes the AMOC to shoal only about half as much as when LGM surface forcing is applied globally. We show that this occurs because diapycnal mixing renders the Southern Ocean overturning circulation more diabatic than previously assumed, which diminishes the influence of Southern Ocean surface buoyancy forcing on the depth of the AMOC. |
format |
Article in Journal/Newspaper |
author |
Sun, S Eisenman, I Stewart, AL |
author_facet |
Sun, S Eisenman, I Stewart, AL |
author_sort |
Sun, S |
title |
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
title_short |
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
title_full |
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
title_fullStr |
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
title_full_unstemmed |
Does Southern Ocean Surface Forcing Shape the Global Ocean Overturning Circulation? |
title_sort |
does southern ocean surface forcing shape the global ocean overturning circulation? |
publisher |
eScholarship, University of California |
publishDate |
2018 |
url |
https://escholarship.org/uc/item/3kx1q270 |
op_coverage |
2413 - 2423 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Sea ice Southern Ocean |
genre_facet |
Antarc* Antarctic Sea ice Southern Ocean |
op_source |
Geophysical Research Letters, vol 45, iss 5 |
op_relation |
qt3kx1q270 https://escholarship.org/uc/item/3kx1q270 |
op_rights |
public |
_version_ |
1766270797755711488 |