The Vertical Current Approximation Nonlinear Force-Free Field Code - Description, Performance Tests, and Measurements of Magnetic Energies Dissipated in Solar Flares

Abstract

In this work we provide an updated description of the Vertical Current Approximation Nonlinear Force-Free Field (VCA-NLFFF) code, which is designed to measure the evolution of the potential, nonpotential, free energies, and the dissipated magnetic energies during solar flares. This code provides a complementary and alternative method to existing traditional NLFFF codes. The chief advantages of the VCA-NLFFF code over traditional NLFFF codes are the circumvention of the unrealistic assumption of a force-free photosphere in the magnetic field extrapolation method, the capability to minimize the misalignment angles between observed coronal loops (or chromospheric fibril structures) and theoretical model field lines, as well as computational speed. In performance tests of the VCA-NLFFF code, by comparing with the NLFFF code of Wiegelmann (2004), we find agreement in the potential, nonpotential, and free energy within a factor of about 1.3, but the Wiegelmann code yields in the average a factor of 2 lower flare energies. The VCA-NLFFF code is found to detect decreases in flare energies in most X, M, and C-class flares. The successful detection of energy decreases during a variety of flares with the VCA-NLFFF code indicates that current-driven twisting and untwisting of the magnetic field is an adequate model to quantify the storage of magnetic energies in active regions and their dissipation during flares. - The VCA-NLFFF code is also publicly available in the Solar SoftWare (SSW).

23 Figures, 50 pages

References in corpus (9)

• Solar Flare Prediction Using SDO/HMI Vector Magnetic Field Data with a Machine-Learning Algorithm
• Why Is the Great Solar Active Region 12192 Flare-Rich But CME-Poor?
• Magnetohydrodynamic Simulation of the X2.2 Solar Flare on 2011 February 15: I. Comparison with the Observations
• Abrupt changes in photospheric magnetic and Lorentz-force vectors during neutral-line flares
• Global Energetics of Solar Flares: I. Magnetic Energies
• Magnetohydrodynamic Simulation of the X2.2 Solar Flare on 2011 February 15: II. Dynamics Connecting the Solar Flare and the Coronal Mass Ejection
• Temporal Evolution of the Magnetic Topology of the NOAA Active Region 11158
• Magnetic Energy Dissipation during the 2014 March 29 Solar Flares
• Sign singularity and flares in solar active region NOAA 11158

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