North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation
Output from a total of 24 state-of-the-art Atmosphere-Ocean General Circulation Models is analyzed. The models were integrated with observed forcing for the period 1850–2000 as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. All models show enhanced variability...
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Online Access: | https://hdl.handle.net/1956/4868 https://doi.org/10.5194/os-7-389-2011 |
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ftunivbergen:oai:bora.uib.no:1956/4868 2023-05-15T17:29:22+02:00 North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation Medhaug, Iselin Furevik, Tore 2011-06-06 application/pdf https://hdl.handle.net/1956/4868 https://doi.org/10.5194/os-7-389-2011 eng eng The University of Bergen https://hdl.handle.net/1956/4868 https://doi.org/10.5194/os-7-389-2011 cristin:825920 Attribution CC BY http://creativecommons.org/licenses/by/3.0/ The Authors Copyright the authors VDP::Mathematics and natural science: 400::Geosciences: 450::Solid earth physics: 451 Peer reviewed Journal article 2011 ftunivbergen https://doi.org/10.5194/os-7-389-2011 2023-03-14T17:40:35Z Output from a total of 24 state-of-the-art Atmosphere-Ocean General Circulation Models is analyzed. The models were integrated with observed forcing for the period 1850–2000 as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. All models show enhanced variability at multi-decadal time scales in the North Atlantic sector similar to the observations, but with a large intermodel spread in amplitudes and frequencies for both the Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). The models, in general, are able to reproduce the observed geographical patterns of warm and cold episodes, but not the phasing such as the early warming (1930s–1950s) and the following colder period (1960s–1980s). This indicates that the observed 20th century extreme in temperatures are due to primarily a fortuitous phasing of intrinsic climate variability and not dominated by external forcing. Most models show a realistic structure in the overturning circulation, where more than half of the available models have a mean overturning transport within the observed estimated range of 13–24 Sverdrup. Associated with a stronger than normal AMOC, the surface temperature is increased and the sea ice extent slightly reduced in the North Atlantic. Individual models show potential for decadal prediction based on the relationship between the AMO and AMOC, but the models strongly disagree both in phasing and strength of the covariability. This makes it difficult to identify common mechanisms and to assess the applicability for predictions. acceptedVersion Article in Journal/Newspaper North Atlantic Sea ice University of Bergen: Bergen Open Research Archive (BORA-UiB) Ocean Science 7 3 389 404 |
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University of Bergen: Bergen Open Research Archive (BORA-UiB) |
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ftunivbergen |
language |
English |
topic |
VDP::Mathematics and natural science: 400::Geosciences: 450::Solid earth physics: 451 |
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VDP::Mathematics and natural science: 400::Geosciences: 450::Solid earth physics: 451 Medhaug, Iselin Furevik, Tore North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
topic_facet |
VDP::Mathematics and natural science: 400::Geosciences: 450::Solid earth physics: 451 |
description |
Output from a total of 24 state-of-the-art Atmosphere-Ocean General Circulation Models is analyzed. The models were integrated with observed forcing for the period 1850–2000 as part of the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. All models show enhanced variability at multi-decadal time scales in the North Atlantic sector similar to the observations, but with a large intermodel spread in amplitudes and frequencies for both the Atlantic Multidecadal Oscillation (AMO) and the Atlantic Meridional Overturning Circulation (AMOC). The models, in general, are able to reproduce the observed geographical patterns of warm and cold episodes, but not the phasing such as the early warming (1930s–1950s) and the following colder period (1960s–1980s). This indicates that the observed 20th century extreme in temperatures are due to primarily a fortuitous phasing of intrinsic climate variability and not dominated by external forcing. Most models show a realistic structure in the overturning circulation, where more than half of the available models have a mean overturning transport within the observed estimated range of 13–24 Sverdrup. Associated with a stronger than normal AMOC, the surface temperature is increased and the sea ice extent slightly reduced in the North Atlantic. Individual models show potential for decadal prediction based on the relationship between the AMO and AMOC, but the models strongly disagree both in phasing and strength of the covariability. This makes it difficult to identify common mechanisms and to assess the applicability for predictions. acceptedVersion |
format |
Article in Journal/Newspaper |
author |
Medhaug, Iselin Furevik, Tore |
author_facet |
Medhaug, Iselin Furevik, Tore |
author_sort |
Medhaug, Iselin |
title |
North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
title_short |
North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
title_full |
North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
title_fullStr |
North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
title_full_unstemmed |
North Atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
title_sort |
north atlantic 20th century multidecadal variability in coupled climate models: sea surface temperature and ocean overturning circulation |
publisher |
The University of Bergen |
publishDate |
2011 |
url |
https://hdl.handle.net/1956/4868 https://doi.org/10.5194/os-7-389-2011 |
genre |
North Atlantic Sea ice |
genre_facet |
North Atlantic Sea ice |
op_relation |
https://hdl.handle.net/1956/4868 https://doi.org/10.5194/os-7-389-2011 cristin:825920 |
op_rights |
Attribution CC BY http://creativecommons.org/licenses/by/3.0/ The Authors Copyright the authors |
op_doi |
https://doi.org/10.5194/os-7-389-2011 |
container_title |
Ocean Science |
container_volume |
7 |
container_issue |
3 |
container_start_page |
389 |
op_container_end_page |
404 |
_version_ |
1766123270585712640 |