Jovian vortices and jets

TL;DR

This paper investigates the formation and stability of isolated vortices in sheared zonal flows using a modified 2-layer quasigeostrophic model, combining computational and analytical methods.

Contribution

It introduces a generalized simulated annealing approach to find steady vortices in a novel layered flow model with a dynamic lower layer.

Findings

Steady vortices can exist under specific flow conditions.

The stability of zonal winds depends on vortex configurations.

The model extends previous layered flow analyses.

Abstract

We explore the conditions required for isolated vortices to exist in sheared zonal flows and the stability of the underlying zonal winds. This is done using the standard 2-layer quasigeostrophic model with the lower layer depth becoming infinite; however, this model differs from the usual layer model because the lower layer is not assumed to be motionless but has a steady configuration of alternating zonal flows [1]. Steady state vortices are obtained by a simulated annealing computational method introduced in [2], generalized and applied in [3] in fluid flow, and used in the context of magnetohydrodynamics in [4-6]. Various cases of vortices with a constant potential vorticity anomaly atop zonal winds and the stability of the underlying winds are considered using a mix of computational and analytical techniques.