Publication:
A thermal oscillation under a restorative forcing

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Authors
Cai, W.J.
Chu, Peter C.
Subjects
Interdecadal oscillations, Restorative forcing, Rossby waves, Thermal circulation
Advisors
Date of Issue
1998
Date
1998
Publisher
Language
Abstract
The authors report an interdecadal oscillation in a wind- and thermally-driven ocean general circulation model (OGCM). The oscillation is tantalizing in that it occursunder a relatively strong thermal damping(26.3 W m-2K-’). Examinations involving a two-dimensional OGCM, a simple thermal ‘flip-flop’ model, and a three-dimensional OGCM with and without the nonlinear effect of temperature in the state equation of sea water demonstrate that the oscillation is not driven by mechanisms such as the so-called convective oscillator, or the advective overshooting oscillator. Instead, the oscillation is associated with the propagation of modelled long Rossby-waves with westward phase velocity. It is found that the north-south basin extent of the OGCM is an important factor; a larger north- south basin extent is conducive to the generation of thermal wind flows crucial for initiating the propagation of disturbances. The geophysical relevance of these results is discussed.
Type
Article
Description
Quarterly Journal of the Royal Meteorological Society
Series/Report No
Department
Oceanography
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NPS Report Number
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Citation
Cai, W.J., and P.C. Chu, 1998: A thermal oscillation under a restorative forcing (paper download). Quarterly Journal of the Royal Meteorological Society, 124, 793-809.
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This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.
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