Effect of Size of the Computational Domain on Spherical Nonlinear Force-Free Modeling of Coronal Magnetic Field Using SDO/HMI Data

TL;DR

This study examines how the size of the computational domain affects the accuracy of spherical nonlinear force-free models of the solar coronal magnetic field using SDO/HMI data, highlighting significant differences in key magnetic quantities.

Contribution

It demonstrates the impact of domain size on modeling results of the solar magnetic field, emphasizing the importance of domain selection in coronal magnetic field modeling.

Findings

Magnetic flux density varies with domain size.

Electric current density differs significantly with domain boundaries.

Free magnetic energy density is affected by the chosen domain extent.

Abstract

The solar coronal magnetic field produces solar activity, including extremely energetic solar flares and coronal mass ejections (CMEs). Knowledge of the structure and evolution of the magnetic field of the solar corona is important for investigating and understanding the origins of space weather. Although the coronal field remains difficult to measure directly, there is considerable interest in accurate modeling of magnetic fields in and around sunspot regions on the Sun using photospheric vector magnetograms as boundary data. In this work, we investigate effects of the size of the domain chosen for coronal magnetic field modeling on resulting model solution. We apply spherical Optimization procedure to vector magnetogram data of Helioseismic and Magnetic Imager (HMI) onboard Solar Dynamics Observatory (SDO) with four Active Region observed on 09 March 2012 at 20:55UT. The results imply that quantities like magnetic flux density, electric current density and free magnetic energy density of ARs of interest are significantly different from the corresponding quantities obtained in the same region within the wider field of view. The difference is even more pronounced in the regions where there are connections to outside the domain.