Oceanic control of multidecadal variability in an idealized coupled GCM
Idealized ocean models are known to develop intrinsic multidecadal oscillations of the meridional overturning circulation (MOC). Here we explore the role of ocean–atmosphere interactions on this low-frequency variability. We use a coupled ocean–atmosphere model set up in a flat-bottom aquaplanet geo...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | English |
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Springer Berlin Heidelberg
2016
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| Online Access: | http://hdl.handle.net/1721.1/104958 |
| _version_ | 1826190376016281600 |
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| author | Jamet, Quentin Huck, Thierry Arzel, Olivier Campin, Jean-Michel de Verdière, Alain Colin |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Jamet, Quentin Huck, Thierry Arzel, Olivier Campin, Jean-Michel de Verdière, Alain Colin |
| author_sort | Jamet, Quentin |
| collection | MIT |
| description | Idealized ocean models are known to develop intrinsic multidecadal oscillations of the meridional overturning circulation (MOC). Here we explore the role of ocean–atmosphere interactions on this low-frequency variability. We use a coupled ocean–atmosphere model set up in a flat-bottom aquaplanet geometry with two meridional boundaries. The model is run at three different horizontal resolutions (4°, 2° and 1°) in both the ocean and atmosphere. At all resolutions, the MOC exhibits spontaneous variability on multidecadal timescales in the range 30–40 years, associated with the propagation of large-scale baroclinic Rossby waves across the Atlantic-like basin. The unstable region of growth of these waves through the long wave limit of baroclinic instability shifts from the eastern boundary at coarse resolution to the western boundary at higher resolution. Increasing the horizontal resolution enhances both intrinsic atmospheric variability and ocean–atmosphere interactions. In particular, the simulated atmospheric annular mode becomes significantly correlated to the MOC variability at 1° resolution. An ocean-only simulation conducted for this specific case underscores the disruptive but not essential influence of air–sea interactions on the low-frequency variability. This study demonstrates that an atmospheric annular mode leading MOC changes by about 2 years (as found at 1° resolution) does not imply that the low-frequency variability originates from air–sea interactions. |
| first_indexed | 2024-09-23T08:39:20Z |
| format | Article |
| id | mit-1721.1/104958 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T08:39:20Z |
| publishDate | 2016 |
| publisher | Springer Berlin Heidelberg |
| record_format | dspace |
| spelling | mit-1721.1/1049582022-09-30T10:19:05Z Oceanic control of multidecadal variability in an idealized coupled GCM Jamet, Quentin Huck, Thierry Arzel, Olivier Campin, Jean-Michel de Verdière, Alain Colin Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Campin, Jean-Michel Idealized ocean models are known to develop intrinsic multidecadal oscillations of the meridional overturning circulation (MOC). Here we explore the role of ocean–atmosphere interactions on this low-frequency variability. We use a coupled ocean–atmosphere model set up in a flat-bottom aquaplanet geometry with two meridional boundaries. The model is run at three different horizontal resolutions (4°, 2° and 1°) in both the ocean and atmosphere. At all resolutions, the MOC exhibits spontaneous variability on multidecadal timescales in the range 30–40 years, associated with the propagation of large-scale baroclinic Rossby waves across the Atlantic-like basin. The unstable region of growth of these waves through the long wave limit of baroclinic instability shifts from the eastern boundary at coarse resolution to the western boundary at higher resolution. Increasing the horizontal resolution enhances both intrinsic atmospheric variability and ocean–atmosphere interactions. In particular, the simulated atmospheric annular mode becomes significantly correlated to the MOC variability at 1° resolution. An ocean-only simulation conducted for this specific case underscores the disruptive but not essential influence of air–sea interactions on the low-frequency variability. This study demonstrates that an atmospheric annular mode leading MOC changes by about 2 years (as found at 1° resolution) does not imply that the low-frequency variability originates from air–sea interactions. 2016-10-24T19:49:08Z 2016-10-24T19:49:08Z 2015-07 2015-02 2016-08-18T15:25:34Z Article http://purl.org/eprint/type/JournalArticle 0930-7575 1432-0894 http://hdl.handle.net/1721.1/104958 Jamet, QuJamet, Quentin et al. “Oceanic Control of Multidecadal Variability in an Idealized Coupled GCM.” Climate Dynamics 46.9–10 (2016): 3079–3095. en http://dx.doi.org/10.1007/s00382-015-2754-3 Climate Dynamics Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. Springer-Verlag Berlin Heidelberg application/pdf Springer Berlin Heidelberg Springer Berlin Heidelberg |
| spellingShingle | Jamet, Quentin Huck, Thierry Arzel, Olivier Campin, Jean-Michel de Verdière, Alain Colin Oceanic control of multidecadal variability in an idealized coupled GCM |
| title | Oceanic control of multidecadal variability in an idealized coupled GCM |
| title_full | Oceanic control of multidecadal variability in an idealized coupled GCM |
| title_fullStr | Oceanic control of multidecadal variability in an idealized coupled GCM |
| title_full_unstemmed | Oceanic control of multidecadal variability in an idealized coupled GCM |
| title_short | Oceanic control of multidecadal variability in an idealized coupled GCM |
| title_sort | oceanic control of multidecadal variability in an idealized coupled gcm |
| url | http://hdl.handle.net/1721.1/104958 |
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