Deep convection-driven vortex formation on Jupiter and Saturn

TL;DR

This paper proposes new mechanisms for vortex formation on Jupiter and Saturn driven by deep planetary convection, supported by 3D simulations, explaining observed vortex properties and large storms like Jupiter's Great Red Spot.

Contribution

It introduces novel formation mechanisms involving deep convection and dynamo effects, supported by three-dimensional turbulent convection simulations.

Findings

Deep turbulent convection generates axial cyclones and anticyclones.

A planetary dynamo promotes large anticyclones, including the Great Red Spot.

The mechanisms explain observed vortex properties on Jupiter and Saturn.

Abstract

The surface of both Jupiter and Saturn has magnificent vortical storms which help shape the dynamic nature of their atmospheres. Land- and space-based observational campaigns over time have established several properties of these vortices, with some being similar between the two planets, while others are different. Shallow-water hydrodynamics, where the vortices are treated as shallow weather-layer phenomenon, is commonly evoked for explaining their formation and properties. Here we report novel formation mechanisms for vortices where the primary driving mechanism is the deep planetary convection occurring in these planets. Using three dimensional simulations of turbulent convection in rotating spherical shells, we propose two ideas: (1) rotating turbulent convection generates deep axially-aligned cyclones and anticyclones; (2) a deep planetary dynamo acts to promote additional anticyclones, some as large as Jupiter's Great Red Spot, in an overlying atmospheric layer. We use these ideas to interpret several observational properties of vortices on Jupiter and Saturn.