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arXiv · 1106.1779

A sustained oscillation in a toy-model of the coupled atmosphere-ocean system

Oliver Bothe
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Abstract

Interaction between atmospheric mid-latitude flow and wind-driven ocean circulation is studied coupling two idealized low-order spectral models. The barotropic Charney-DeVore model with three components simulates a bimodal mid-latitude atmospheric circulation in a channel with two stable flow patterns induced by topography. The wind-driven ocean double gyre circulation in a square basin (of half the channel length) is modeled by an equivalent barotropic formulation of the Veronis model with 21 components, which captures Rossby-wave dynamics and nonlinear decadal variability. When coupled, the atmosphere forces the ocean by wind-stress while, simultaneously, the ocean affects the atmosphere by thermal forcing in terms of a vorticity source. Coupled atmosphere-ocean simulations show two stable flow patterns associated with the topographically induced atmospheric bimodality and a sustained oscillation due to interaction between atmospheric bimodality and oceanic Rossby dynamics. The oscillation is of inter-annual to inter-decadal periodicity and occurs in a reasonably wide parameter domain.

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Oliver Bothe. 2011-06-09. A sustained oscillation in a toy-model of the coupled atmosphere-ocean system. https://arxiv.org/abs/1106.1779

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