Nonlinear force-free field modeling of a solar active region using SDO/HMI and SOLIS/VSM data

Abstract

We use SDO/HMI and SOLIS/VSM photospheric magnetic field measurements to model the force-free coronal field above a solar active region, assuming magnetic forces to dominate. We take measurement uncertainties caused by, e.g., noise and the particular inversion technique into account. After searching for the optimum modeling parameters for the particular data sets, we compare the resulting nonlinear force-free model fields. We show the degree of agreement of the coronal field reconstructions from the different data sources by comparing the relative free energy content, the vertical distribution of the magnetic pressure and the vertically integrated current density. Though the longitudinal and transverse magnetic flux measured by the VSM and HMI is clearly different, we find considerable similarities in the modeled fields. This indicates the robustness of the algorithm we use to calculate the nonlinear force-free fields against differences and deficiencies of the photospheric vector maps used as an input. We also depict how much the absolute values of the total force-free, virial and the free magnetic energy differ and how the orientation of the longitudinal and transverse components of the HMI- and VSM-based model volumes compares to each other.

9 pages, 5 figures

References in corpus (6)

• Optimization code with weighting function for the reconstruction of coronal magnetic fields
• Non-linear force-free field modeling of a solar active region around the time of a major flare and coronal mass ejection
• Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State
• Can We Improve the Preprocessing of Photospheric Vector Magnetograms by the Inclusion of Chromospheric Observations?
• First nonlinear force-free field extrapolations of SOLIS/VSM data
• Magnetic Stereoscopy

Cited by in corpus (8)

• Limitations of force-free magnetic field extrapolations: revisiting basic assumptions
• Full-disk nonlinear force-free field extrapolation of SDO/HMI and SOLIS/VSM magnetograms
• Bihelical spectrum of solar magnetic helicity and its evolution
• Comparison of force-free coronal magnetic field modeling using vector fields from Hinode and Solar Dynamics Observatory
• Structure and evolution of the photospheric magnetic field in 2010 - 2017: comparison of SOLIS/VSM vector field and $B_{LOS}$ potential field
• On measuring divergence for magnetic field modeling
• The effect of spatial sampling on magnetic field modeling and helicity computation
• Temporal and spatial relationship of flare signatures and the force-free coronal magnetic field