Self-consistent Nonlinear Force-free Field Reconstruction from Weighted Boundary Conditions
arXiv:2004.12510 · doi:10.1007/s11207-020-01663-7
Abstract
Vector magnetogram data are often used as photospheric boundary conditions for force-free coronal magnetic field extrapolations. In general, however, vector magnetogram data are not consistent with the force-free assumption. In this article, we demonstrate a way to deal with inconsistent boundary data, by generalizing the "self-consistency procedure" of Wheatland & Regnier (2009). In that procedure, the inconsistency is resolved by an iterative process of constructing two solutions based on the values of the force-free parameter alpha on the two polarities of the field in the boundary (the P and N polarities), and taking uncertainty-weighted averages of the boundary alpha values in the P and N solutions. When the alpha values in the P and N regions are very different, the self-consistent solution may lose high alpha values from the boundary conditions. We show how, by altering the weighting of the uncertainties in the P or N boundary conditions, we can preserve high alpha values in the self-consistent solution. The weighted self-consistent extrapolation method is demonstrated on an analytic bipole field and applied to vector magnetogram data taken by the Helioseismic and Magnetic Imager (HMI) instrument for NOAA active region AR 12017 on 2014 March 29.
12 pages, 5 figures, submitted to Solar Physics
References in corpus (21)
- The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: SHARPs -- Space-weather HMI Active Region Patches
- The Helioseismic and Magnetic Imager (HMI) Vector Magnetic Field Pipeline: Overview and Performance
- Optimization code with weighting function for the reconstruction of coronal magnetic fields
- Preprocessing of vector magnetograph data for a non-linear force-free magnetic field reconstruction
- A Critical Assessment of Nonlinear Force-Free Field Modeling of the Solar Corona for Active Region 10953
- Non-linear force-free field modeling of a solar active region around the time of a major flare and coronal mass ejection
- Using Coronal Loops to Reconstruct the Magnetic Field of an Active Region Before and After a Major Flare
- Nonlinear Force-Free Extrapolation of the Coronal Magnetic Field Based on the MHD Relaxation Method
- A self-consistent nonlinear force-free solution for a solar active region magnetic field
- The fast filament eruption leading to the X-flare on March 29, 2014
- Magnetic Field Extrapolations in the Corona: Success and Future Improvements
- Magnetohydrodynamic Modeling of a Solar Eruption Associated with X9.3 Flare Observed in Active Region 12673
- Reconstructing the Local Twist of Coronal Magnetic Fields and the Three-Dimensional Shape of the Field Lines from Coronal Loops in EUV and X-Ray Images
- The eruption of a small-scale emerging flux rope as the driver of an M-class flare and a coronal mass ejection
- Quantifying the Topology and Evolution of a Magnetic Flux Rope Associated with Multi-flare Activities
- Flare Energy Release in the Lower Solar Atmosphere Near the Magnetic Field Polarity Inversion Line
- On the Coordinate System of Space-Weather HMI Active Region Patches (SHARPs): A Technical Note
- The Triggering of the 29-March-2014 Filament Eruption
- Magnetic Energy Storage and Current Density Distributions for Different Force-Free Models
- Nonlinear force-free modeling of flare-related magnetic field changes at the photosphere and chromosphere
- Relative Magnetic Helicity Based on a Periodic Potential Field