A self-consistent model of the solar tachocline

TL;DR

This paper introduces a fully nonlinear 3D simulation model of the solar tachocline, demonstrating how it naturally forms and maintains a steady state through complex force balances involving magnetic fields, turbulence, and rotation.

Contribution

It provides the first self-consistent numerical simulation showing the formation and equilibrium of the solar tachocline with realistic force interactions.

Findings

Tachocline forms naturally in the simulation as a steady force balance.

Primordial magnetic field maintains uniform rotation in the radiation zone.

Balanced dynamics previously seen only in idealized models now demonstrated in fully nonlinear simulations.

Abstract

We present a local but fully nonlinear model of the solar tachocline, using three-dimensional direct numerical simulations. The tachocline forms naturally as a statistically steady balance between Coriolis, pressure, buoyancy and Lorentz forces beneath a turbulent convection zone. Uniform rotation is maintained in the radiation zone by a primordial magnetic field, which is confined by meridional flows in the tachocline and convection zone. Such balanced dynamics has previously been found in idealised laminar models, but never in fully self-consistent numerical simulations.