Solar differential rotation: hints to reproduce a near-surface shear layer in global simulations

TL;DR

This paper uses numerical simulations to explore solar interior flows, successfully reproducing key features like the tachocline and near-surface shear layer, and analyzing how resolution affects results.

Contribution

It demonstrates the ability to reproduce solar-like rotation features in global simulations and examines the impact of grid resolution on simulation outcomes.

Findings

Reproduced tachocline and near-surface shear layer.

Identified transition between buoyancy and rotation dominated regimes.

Showed simulation results depend on grid resolution.

Abstract

Convective turbulent motions in the solar interior, as well as the mean flows resulting from them, determine the evolution of the solar magnetic field. With the aim to get a better understanding of these flows we study anelastic rotating convection in a spherical shell whose stratification resembles that of the solar interior. This study is done through numerical simulations performed with the EULAG code. Due to the numerical formulation, these simulations are known as implicit large eddy simulations (ILES), since they intrinsically capture the contribution of, non-resolved, small scales at the same time maximizing the effective Reynolds number. We reproduce some previous results and find a transition between buoyancy and rotation dominated regimes which results in anti-solar or solar like rotation patterns. Even thought the rotation profiles are dominated by Taylor-Proudman columnar rotation, we are able to reproduce the tachocline and a low latitude near-surface shear layer. We find that simulations results depend on the grid resolution as a consequence of a different sub-grid scale contribution.