The Force-Free Electrodynamics Method for the Extrapolation of Coronal Magnetic Fields from Vector Magnetograms

TL;DR

This paper introduces an improved force-free electrodynamics numerical method in spherical coordinates for accurately extrapolating coronal magnetic fields from photospheric magnetograms, ensuring boundary and divergence conditions are met.

Contribution

An enhanced FFE numerical code that accurately extrapolates solar coronal magnetic fields while satisfying boundary and divergence constraints.

Findings

Code satisfies boundary conditions and divB=0 to machine precision.

Performance comparable to existing nonlinear force-free extrapolation methods.

Validated with standard convergence parameters.

Abstract

We present a new improved version of our force-free electrodynamics (FFE) numerical code in spherical coordinates that extrapolates the magnetic field in the inner solar corona from a photospheric vector magnetogram. The code satisfies the photospheric boundary condition and the condition divB=0 to machine accuracy. The performance of our method is evaluated with standard convergence parameters, and is found to be comparable to that of other nonlinear force-free extrapolations.