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| Titel |
The Atlantic Meridional Overturning Circulation's Response to Variable Buoyancy Forcing |
| VerfasserIn |
Edward Butler, Kevin Oliver, Joel Hirschi |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250089805
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| Publikation (Nr.) |
 EGU/EGU2014-4018.pdf |
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| Zusammenfassung |
| The Meridional Overturning Circulation (MOC) is a large-scale global circulation of water
(and heat) throughout the world’s ocean. It is an integral part of the climate system,
responsible for significant anomalous warming of the North Atlantic region. Much of our
current understanding of the MOC is based on equilibrium theories. However, the
MOC is not a steady circulation and exhibits variability across a broad range of
timescales. We examine the transient response of global ocean overturning, with
particular emphasis on the Atlantic MOC (AMOC), to periodic variations in the
North Atlantic meridional density gradient on decadal, centennial, and millennial
timescales within the Nucleus for European Modelling of the Ocean (NEMO) model
framework. We use the ORCA2 global ocean configuration of NEMO (with realistic
topography and a horizontal resolution of 2°) and impose periodic variations in air
temperature over the North Atlantic. In response, we see large oscillations in the
strength of the AMOC which peak in magnitude at 128-year timescales. A scaling
relationship of the form Ψ ~ ΔÏH2 (in which ΔÏ is a measure of meridional density
gradient and H is the depth scale of maximal overturning) is found to hold for
the AMOC in these transient simulations with strongest correlations observed at
centennial timescales. We explore the validity of this scaling relationship across a broad
range of spatial and temporal scales and discuss its validity in a global context. |
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