Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N
The Coupled Model Intercomparison Project (CMIP) allows assessment of the representation of the Atlantic Meridional Overturning Circulation (AMOC) in climate models. While CMIP Phase 6 models display a large spread in AMOC strength by a factor of three, the multi-model mean strength agrees reasonabl...
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ftsouthampton:oai:eprints.soton.ac.uk:484880 2024-05-12T07:56:39+00:00 Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N Bryden, Harry Drijfhout, Sybren Hazeleger, Wilco Mecking, Jennifer 2024-02-29 text https://eprints.soton.ac.uk/484880/ https://eprints.soton.ac.uk/484880/1/finalBBDHM2Feb.pdf en English eng https://eprints.soton.ac.uk/484880/1/finalBBDHM2Feb.pdf Bryden, Harry, Drijfhout, Sybren, Hazeleger, Wilco and Mecking, Jennifer (2024) Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N. Ocean Science. (In Press) accepted_manuscript Article PeerReviewed 2024 ftsouthampton 2024-04-17T14:08:58Z The Coupled Model Intercomparison Project (CMIP) allows assessment of the representation of the Atlantic Meridional Overturning Circulation (AMOC) in climate models. While CMIP Phase 6 models display a large spread in AMOC strength by a factor of three, the multi-model mean strength agrees reasonably well with observed estimates from RAPID1, but this does not hold for its various components. In CMIP6 the present-day AMOC is characterised by a lack of lower North Atlantic Deep Water (lNADW), due to the small-scale of Greenland-Iceland-Scotland Ridge overflow and too much mixing. This is compensated by increased recirculation in the subtropical gyre and more Antarctic Bottom Water (AABW). Deep-water circulation is dominated by a distinct deep western boundary current (DWBC) with minor interior recirculation compared to observations. The future decline in the AMOC to 2100 of 7Sv under a SSP5-8.5 scenario is associated with decreased northward western boundary current transport in combination with reduced southward flow of upper North Atlantic Deep Water (uNADW). In CMIP6, wind stress curl decreases with time by 14% so that the wind-driven thermocline recirculation in the subtropical gyre is reduced by 4 Sv (17%) by 2100. The reduction in western boundary current transport of 11Sv is more than the decrease in the wind-driven gyre transport suggesting a decrease over time in the component of the Gulf Stream originating in the South Atlantic. Article in Journal/Newspaper Antarc* Antarctic Greenland Iceland North Atlantic Deep Water North Atlantic University of Southampton: e-Prints Soton Antarctic Curl ENVELOPE(-63.071,-63.071,-70.797,-70.797) Greenland |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
The Coupled Model Intercomparison Project (CMIP) allows assessment of the representation of the Atlantic Meridional Overturning Circulation (AMOC) in climate models. While CMIP Phase 6 models display a large spread in AMOC strength by a factor of three, the multi-model mean strength agrees reasonably well with observed estimates from RAPID1, but this does not hold for its various components. In CMIP6 the present-day AMOC is characterised by a lack of lower North Atlantic Deep Water (lNADW), due to the small-scale of Greenland-Iceland-Scotland Ridge overflow and too much mixing. This is compensated by increased recirculation in the subtropical gyre and more Antarctic Bottom Water (AABW). Deep-water circulation is dominated by a distinct deep western boundary current (DWBC) with minor interior recirculation compared to observations. The future decline in the AMOC to 2100 of 7Sv under a SSP5-8.5 scenario is associated with decreased northward western boundary current transport in combination with reduced southward flow of upper North Atlantic Deep Water (uNADW). In CMIP6, wind stress curl decreases with time by 14% so that the wind-driven thermocline recirculation in the subtropical gyre is reduced by 4 Sv (17%) by 2100. The reduction in western boundary current transport of 11Sv is more than the decrease in the wind-driven gyre transport suggesting a decrease over time in the component of the Gulf Stream originating in the South Atlantic. |
format |
Article in Journal/Newspaper |
author |
Bryden, Harry Drijfhout, Sybren Hazeleger, Wilco Mecking, Jennifer |
spellingShingle |
Bryden, Harry Drijfhout, Sybren Hazeleger, Wilco Mecking, Jennifer Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
author_facet |
Bryden, Harry Drijfhout, Sybren Hazeleger, Wilco Mecking, Jennifer |
author_sort |
Bryden, Harry |
title |
Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
title_short |
Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
title_full |
Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
title_fullStr |
Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
title_full_unstemmed |
Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N |
title_sort |
comparing observed and modelled components of the atlantic meridional overturning circulation at 26°n |
publishDate |
2024 |
url |
https://eprints.soton.ac.uk/484880/ https://eprints.soton.ac.uk/484880/1/finalBBDHM2Feb.pdf |
long_lat |
ENVELOPE(-63.071,-63.071,-70.797,-70.797) |
geographic |
Antarctic Curl Greenland |
geographic_facet |
Antarctic Curl Greenland |
genre |
Antarc* Antarctic Greenland Iceland North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic Greenland Iceland North Atlantic Deep Water North Atlantic |
op_relation |
https://eprints.soton.ac.uk/484880/1/finalBBDHM2Feb.pdf Bryden, Harry, Drijfhout, Sybren, Hazeleger, Wilco and Mecking, Jennifer (2024) Comparing observed and modelled components of the Atlantic Meridional Overturning Circulation at 26°N. Ocean Science. (In Press) |
op_rights |
accepted_manuscript |
_version_ |
1798836851520307200 |