Patterns of convection in rotating spherical shells

TL;DR

This paper investigates convection patterns in rotating spherical shells through numerical simulations, focusing on regular dynamical features near the convection threshold relevant to laboratory and space experiments.

Contribution

It provides new insights into the behavior of convection patterns, including amplitude vacillations and spatial modulations, across different Prandtl number regimes.

Findings

Regular convection features near threshold are identified.

Equatorially attached convection transitions to chaos at low Prandtl numbers.

Relationships between structured convection and turbulence are analyzed.

Abstract

Patterns of convection in internally heated, self-gravitating rotating spherical fluid shells are investigated through numerical simulations. While turbulent states are of primary interest in planetary and stellar applications the present paper emphasizes more regular dynamical features at Rayleigh numbers not far above threshold which are similar to those which might be observed in laboratory or space experiments. Amplitude vacillations and spatial modulations of convection columns are common features at moderate and large Prandtl numbers. In the low Prandtl number regime equatorially attached convection evolves differently with increasing Rayleigh number and exhibits an early transition into a chaotic state. Relationships of the dynamical features to coherent structures in fully turbulent convection states are emphasized.