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Please use this identifier to cite or link to this item:
http://hdl.handle.net/1956/630
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Full metadata record
| DC Field | Value | Language |
|---|
| contributor.author | Bentsen, Mats | - |
| contributor.author | Drange, Helge | - |
| contributor.author | Furevik, Tore | - |
| contributor.author | Zhou, Tianjun | - |
| date.accessioned | 2005-03-29T13:02:27Z | - |
| date.available | 2005-03-29T13:02:27Z | - |
| date.issued | 2004-04-17 | - |
| identifier.citation | http://www.springerlink.com/openurl.asp?genre=article&issn=0930-7575&volume=22&issue=6&spage=701 | en |
| identifier.issn | 0930-7575 | - |
| identifier.uri | DOI: 10.1007/s00382-004-0397-x | - |
| identifier.uri | http://hdl.handle.net/1956/630 | - |
| description.abstract | To examine the multi-annual to decadal scale variability of the Atlantic Meridional
Overturning Circulation (AMOC), a four-member ensemble with a daily reanalysis
forced, medium-resolution global version of the isopycnic coordinate ocean
model MICOM, and a 300-years integration with the fully coupled Bergen Climate
Model (BCM), have been conducted.
The simulations of the AMOC with both model systems yield a long-term mean
value of 18 Sv and decadal variability with an amplitude of 1–3 Sv. The power spectrum
of the inter-annual to decadal scale variability of the AMOC in BCM generally
follows the theoretical red noise spectrum, with indications of increased power near
the 20-years period. Comparison with observational proxy indices for the AMOC,
e.g. the thickness of the Labrador Sea Water, the strength of the baroclinic gyre circulation
in the North Atlantic Ocean, and the surface temperature anomalies along
the mean path of the Gulf Stream, shows similar trends and phasing of the variability,
indicating that the simulated AMOC variability is robust and real.
Mixing indices have been constructed for the Labrador, the Irminger and the
Greenland-Iceland-Norwegian (GIN) Seas. While convective mixing in the Labrador
and the GIN Seas are in opposite phase, and linked to the NAO as observations
suggest, the convective mixing in the Irminger Sea is in phase with or leads the
Labrador Sea. Newly formed deep water is seen as a slow, anomalous cold and
fresh, plume flowing southward along the western continental slope of the Atlantic
Ocean, with a return flow of warm and saline water in the surface. In addition, fasttravelling
topographically-trapped waves propagate southward along the continental
slope towards equator, where they go east and continue along the eastern rim of the
Atlantic.
For both types of experiments, the Northern Hemisphere sea level pressure and
2 m temperature anomaly patterns computed based on the di erence between climate
states with strong and weak AMOC yields a NAO-like pattern with intensified
Icelandic low and Azores high, and a warming of 0.25–0.5C of the central North
Atlantic sea surface temperature (SST). The reanalysis forced simulations indicate a
coupling between the Labrador Sea Water production rate and an equatorial Atlantic
SST index in accordance with observations. This coupling is not identified in the
coupled simulation. | en |
| format.extent | 3022317 bytes | - |
| format.mimetype | application/pdf | - |
| language.iso | en | - |
| publisher | Springer-Verlag | en |
| relation.ispartofseries | Climate Dynamics;22(6/7) | - |
| title | Simulated variability of the Atlantic meridional overturning circulation | en |
| type | Preprint | en |
| Appears in Collections: | Eprints by Nansen Environmental and Remote Sensing Center (NERSC)
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| thc.pdf | 2951Kb | Adobe PDF | View/Open |
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