Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode
The meridional overturning circulation (MOC) in the coupled ECHAM5/MPIOM exhibits variability at periods of near 30 years and near 60 years. The 30-year variability, referred to as interdecadal variability (IDV), exist in an ocean model driven by climatological atmospheric forcing, suggesting that i...
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ftpubman:oai:pure.mpg.de:item_994254 2023-08-27T04:10:41+02:00 Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode Zhu, X. Jungclaus, J. 2008 application/pdf http://hdl.handle.net/11858/00-001M-0000-0011-FA5F-2 http://hdl.handle.net/11858/00-001M-0000-0011-FA5E-4 eng eng info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-008-0383-9 http://hdl.handle.net/11858/00-001M-0000-0011-FA5F-2 http://hdl.handle.net/11858/00-001M-0000-0011-FA5E-4 Climate Dynamics info:eu-repo/semantics/article 2008 ftpubman https://doi.org/10.1007/s00382-008-0383-9 2023-08-02T01:35:07Z The meridional overturning circulation (MOC) in the coupled ECHAM5/MPIOM exhibits variability at periods of near 30 years and near 60 years. The 30-year variability, referred to as interdecadal variability (IDV), exist in an ocean model driven by climatological atmospheric forcing, suggesting that it is maintained by ocean dynamics; the 60-year variability, the multidecadal variability (MDV), is only observed in the fully coupled model and therefore is interpreted as an atmosphere–ocean coupled mode. The coexistence of the 30-year IDV and the 60-year MDV provides a possible explanation for the widespread time scales observed in climate variables. Further analyses of the climatologically forced ocean model shows that, the IDV is related to the interplay between the horizontal temperature-dominated density gradients and the ocean circulation: temperature anomalies move along the cyclonic subpolar gyre leading to fluctuations in horizontal density gradients and the subsequent weakening and strengthening of the MOC. This result is consistent with that from less complex models, indicating the robustness of the IDV. We further show that, along the North Atlantic Current path, the sea surface temperature anomalies are determined by the slow LSW advection at the intermediate depth. Article in Journal/Newspaper north atlantic current North Atlantic Max Planck Society: MPG.PuRe Climate Dynamics 31 6 731 741 |
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Open Polar |
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Max Planck Society: MPG.PuRe |
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ftpubman |
language |
English |
description |
The meridional overturning circulation (MOC) in the coupled ECHAM5/MPIOM exhibits variability at periods of near 30 years and near 60 years. The 30-year variability, referred to as interdecadal variability (IDV), exist in an ocean model driven by climatological atmospheric forcing, suggesting that it is maintained by ocean dynamics; the 60-year variability, the multidecadal variability (MDV), is only observed in the fully coupled model and therefore is interpreted as an atmosphere–ocean coupled mode. The coexistence of the 30-year IDV and the 60-year MDV provides a possible explanation for the widespread time scales observed in climate variables. Further analyses of the climatologically forced ocean model shows that, the IDV is related to the interplay between the horizontal temperature-dominated density gradients and the ocean circulation: temperature anomalies move along the cyclonic subpolar gyre leading to fluctuations in horizontal density gradients and the subsequent weakening and strengthening of the MOC. This result is consistent with that from less complex models, indicating the robustness of the IDV. We further show that, along the North Atlantic Current path, the sea surface temperature anomalies are determined by the slow LSW advection at the intermediate depth. |
format |
Article in Journal/Newspaper |
author |
Zhu, X. Jungclaus, J. |
spellingShingle |
Zhu, X. Jungclaus, J. Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
author_facet |
Zhu, X. Jungclaus, J. |
author_sort |
Zhu, X. |
title |
Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
title_short |
Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
title_full |
Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
title_fullStr |
Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
title_full_unstemmed |
Interdecadal variability of the Meridional Overturning Circulation as an ocean internal mode |
title_sort |
interdecadal variability of the meridional overturning circulation as an ocean internal mode |
publishDate |
2008 |
url |
http://hdl.handle.net/11858/00-001M-0000-0011-FA5F-2 http://hdl.handle.net/11858/00-001M-0000-0011-FA5E-4 |
genre |
north atlantic current North Atlantic |
genre_facet |
north atlantic current North Atlantic |
op_source |
Climate Dynamics |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1007/s00382-008-0383-9 http://hdl.handle.net/11858/00-001M-0000-0011-FA5F-2 http://hdl.handle.net/11858/00-001M-0000-0011-FA5E-4 |
op_doi |
https://doi.org/10.1007/s00382-008-0383-9 |
container_title |
Climate Dynamics |
container_volume |
31 |
container_issue |
6 |
container_start_page |
731 |
op_container_end_page |
741 |
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1775352919263019008 |