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Please use this identifier to cite or link to this item:
http://hdl.handle.net/1956/420
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Full metadata record
| DC Field | Value | Language |
|---|
| contributor.author | Bentsen, M. | en_US |
| contributor.author | Drange, H. | en_US |
| contributor.author | Furevik, T. | en_US |
| contributor.author | Zhou, T. | en_US |
| date.accessioned | 2004-08-12T11:14:43Z | en_US |
| date.accessioned | 2004-08-26T11:59:14Z | - |
| date.available | 2004-08-12T11:14:43Z | en_US |
| date.available | 2004-08-26T11:59:14Z | - |
| date.issued | 2004-04-17 | en_US |
| identifier.issn | 0930-7575 | en_US |
| identifier.issn | 1432-0894 | en_US |
| identifier.uri | http://hdl.handle.net/1956/420 | - |
| description.abstract | To examine the multi-annual to decadal scale
variability of the Atlantic Meridional Overturning Circulation
(AMOC) we conducted 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). 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 on the surface. In addition, fast-travelling 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 difference between
climate states with strong and weak AMOC yields a
NAO-like pattern with intensified Icelandic low and
Azores high, and a warming of 0.25–0.5 C 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_US |
| format.extent | 1501478 bytes | en_US |
| format.extent | 71752 bytes | - |
| format.extent | 1830 bytes | - |
| format.extent | 1501478 bytes | - |
| format.mimetype | application/pdf | en_US |
| format.mimetype | text/plain | - |
| format.mimetype | text/plain | - |
| format.mimetype | application/pdf | - |
| language.iso | en | en_US |
| publisher | Springer | en_US |
| relation.ispartofseries | Climate Dynamics;22(6/7) | en_US |
| title | Simulated variability of the Atlantic meridional overturning circulation | en_US |
| type | Article | en_US |
| Appears in Collections: | Eprints by the Geophysical Institute
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| File |
Size | Format |
|---|
| GF-bentsen.pdf | 1466Kb | Adobe PDF | View/Open |
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