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arXiv · 2101.05375

Nonlinear saturation of thermal instabilities

F. J. Beron-Vera
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Abstract

Low-frequency simulations of a one-layer model with lateral buoyancy variations (i.e., thermodynamically active) have revealed circulatory motions resembling quite closely submesoscale observations in the surface ocean rather than indefinitely growing in the absence of a high-wavenumber instability cutoff. In this note it is shown that the existence of a convex pseudoenergy--momentum integral of motion for the inviscid, unforced dynamics provides a mechanism for the nonlinear saturation of such thermal instabilities in the zonally symmetric case. The result is an application of \citet{Arnold-66} and \citet{Shepherd-88a} methods.

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F. J. Beron-Vera. 2021-01-13. Nonlinear saturation of thermal instabilities. https://doi.org/10.1063/5.0045191

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