Simulation of Flux Emergence from the Convection Zone to the Corona

TL;DR

This paper presents detailed numerical simulations of magnetic flux emergence from the solar convection zone into the corona, revealing the complex interactions with turbulent plasma and the resulting magnetic structures.

Contribution

It introduces a comprehensive simulation model including radiative losses, non-ideal equations of state, and empirical heating, to study flux emergence dynamics.

Findings

Convection influences the morphology of emerging magnetic structures.

Magnetic flux can disrupt convection patterns and form ephemeral regions.

A coherent shear pattern develops in the low corona during flux emergence.

Abstract

Here, we present numerical simulations of magnetic flux buoyantly rising from a granular convection zone into the low corona. We study the complex interaction of the magnetic field with the turbulent plasma. The model includes the radiative loss terms, non-ideal equations of state, and empirical corona heating. We find that the convection plays a crucial role in shaping the morphology and evolution of the emerging structure. The emergence of magnetic fields can disrupt the convection pattern as the field strength increases, and form an ephemeral region-like structure, while weak magnetic flux emerges and quickly becomes concentrated in the intergranular lanes, i.e. downflow regions. As the flux rises, a coherent shear pattern in the low corona is observed in the simulation. In the photosphere, both magnetic shearing and velocity shearing occur at a very sharp polarity inversion line (PIL). In a case of U-loop magnetic field structure, the field above the surface is highly sheared while below it is relaxed.