Deep convection-driven vortex formation 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.

16 Pages, 3 main and 7 supplementary figures, 2 animations on youtube

References in corpus (11)

• Large-scale vortices in rapidly rotating Rayleigh-Bénard convection
• Approaching a realistic force balance in geodynamo simulations
• Saturn's deep atmospheric flows revealed by the Cassini Grand Finale gravity measurements
• Explaining Jupiter's magnetic field and equatorial jet dynamics
• Understanding Jupiter's Interior
• Zonal flow scaling in rapidly-rotating compressible convection
• The landscape of Saturn's internal magnetic field from the Cassini Grand Finale
• Deep rotating convection generates the polar hexagon on Saturn
• Anelastic spherical dynamos with radially variable electrical conductivity
• Effects of a radially varying electrical conductivity on 3D numerical dynamos
• Deep model simulation of polar vortices in gas giant atmospheres