Magnetic Connectivity Between Active Regions 10987, 10988, and 10989 by Means of Nonlinear Force-Free Field Extrapolation

2011 ◽  
pp. 119-130
Author(s):  
Tilaye Tadesse ◽  
T. Wiegelmann ◽  
B. Inhester ◽  
A. Pevtsov
Keyword(s):  
Free Field ◽  
Active Regions ◽  
Nonlinear Force ◽  
Force Free Field

scholarly journals Nonlinear force-free modeling of magnetic fields in flare-productive active regions

2015 ◽  
Vol 11 (S320) ◽  
pp. 167-174
Author(s):  
M. S. Wheatland ◽  
S. A. Gilchrist
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Boundary Data ◽  
Numerical Solutions ◽  
Free Field ◽  
Active Regions ◽  
Coronal Magnetic Field ◽  
Nonlinear Force ◽  
The Magnetic Field ◽  
Force Free Field

AbstractWe review nonlinear force-free field (NLFFF) modeling of magnetic fields in active regions. The NLFFF model (in which the electric current density is parallel to the magnetic field) is often adopted to describe the coronal magnetic field, and numerical solutions to the model are constructed based on photospheric vector magnetogram boundary data. Comparative tests of NLFFF codes on sets of boundary data have revealed significant problems, in particular associated with the inconsistency of the model and the data. Nevertheless NLFFF modeling is often applied, in particular to flare-productive active regions. We examine the results, and discuss their reliability.

scholarly journals Magnetic Connectivity Between Active Regions 10987, 10988, and 10989 by Means of Nonlinear Force-Free Field Extrapolation

Solar Physics ◽  
2011 ◽  
Vol 277 (1) ◽  
pp. 119-130 ◽  
Author(s):  
Tilaye Tadesse ◽  
T. Wiegelmann ◽  
B. Inhester ◽  
A. Pevtsov
Keyword(s):  
Free Field ◽  
Active Regions ◽  
Nonlinear Force ◽  
Force Free Field

scholarly journals Simulating the Coronal Evolution of Bipolar Active Regions to Investigate the Formation of Flux Ropes

Solar Physics ◽  
2021 ◽  
Vol 296 (1) ◽  
Author(s):  
S. L. Yardley ◽  
D. H. Mackay ◽  
L. M. Green
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Initial Conditions ◽  
Free Field ◽  
Active Regions ◽  
Coronal Magnetic Field ◽  
Solar Dynamics Observatory ◽  
Horizontal Magnetic Field ◽  
Nonlinear Force ◽  
Force Free Field

AbstractThe coronal magnetic field evolution of 20 bipolar active regions (ARs) is simulated from their emergence to decay using the time-dependent nonlinear force-free field method of Mackay, Green, and van Ballegooijen (Astrophys. J. 729, 97, 2011). A time sequence of cleaned photospheric line-of-sight magnetograms, which covers the entire evolution of each AR, is used to drive the simulation. A comparison of the simulated coronal magnetic field with the 171 and 193 Å observations obtained by the Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA), is made for each AR by manual inspection. The results show that it is possible to reproduce the evolution of the main coronal features such as small- and large-scale coronal loops, filaments and sheared structures for 80% of the ARs. Varying the boundary and initial conditions, along with the addition of physical effects such as Ohmic diffusion, hyperdiffusion and a horizontal magnetic field injection at the photosphere, improves the match between the observations and simulated coronal evolution by 20%. The simulations were able to reproduce the build-up to eruption for 50% of the observed eruptions associated with the ARs. The mean unsigned time difference between the eruptions occurring in the observations compared to the time of eruption onset in the simulations was found to be ≈5 hrs. The simulations were particularly successful in capturing the build-up to eruption for all four eruptions that originated from the internal polarity inversion line of the ARs. The technique was less successful in reproducing the onset of eruptions that originated from the periphery of ARs and large-scale coronal structures. For these cases global, rather than local, nonlinear force-free field models must be used. While the technique has shown some success, eruptions that occur in quick succession are difficult to reproduce by this method and future iterations of the model need to address this.

Studying Magnetic Field Variations Accompanying the 2011 June 7 Eruptive Event, by Using Nonlinear Force-Free Field Modeling

Solar Physics ◽  
2020 ◽  
Vol 295 (4) ◽  
Author(s):  
Y. I. Egorov ◽  
V. G. Fainshtein ◽  
I. I. Myshyakov ◽  
S. A. Anfinogentov ◽  
G. V. Rudenko
Keyword(s):  
Magnetic Field ◽  
Free Field ◽  
Eruptive Event ◽  
Field Modeling ◽  
Nonlinear Force ◽  
Magnetic Field Variations ◽  
Force Free Field

scholarly journals A NEW CODE FOR NONLINEAR FORCE-FREE FIELD EXTRAPOLATION OF THE GLOBAL CORONA

2012 ◽  
Vol 755 (1) ◽  
pp. 62 ◽  
Author(s):  
Chaowei Jiang ◽  
Xueshang Feng ◽  
Changqing Xiang
Keyword(s):  
Free Field ◽  
Nonlinear Force ◽  
Force Free Field

A New and Fast Way to Reconstruct a Nonlinear Force‐free Field in the Solar Corona

2006 ◽  
Vol 649 (2) ◽  
pp. 1084-1092 ◽  
Author(s):  
M. T. Song ◽  
C. Fang ◽  
Y. H. Tang ◽  
S. T. Wu ◽  
Y. A. Zhang
Keyword(s):  
Solar Corona ◽  
Free Field ◽  
Nonlinear Force ◽  
Force Free Field

scholarly journals Nonlinear Force‐free Field Modeling of a Solar Active Region around the Time of a Major Flare and Coronal Mass Ejection

2008 ◽  
Vol 675 (2) ◽  
pp. 1637-1644 ◽  
Author(s):  
C. J. Schrijver ◽  
M. L. DeRosa ◽  
T. Metcalf ◽  
G. Barnes ◽  
B. Lites ◽  
...  
Keyword(s):  
Active Region ◽  
Coronal Mass Ejection ◽  
Free Field ◽  
Solar Active Region ◽  
Field Modeling ◽  
Major Flare ◽  
Nonlinear Force ◽  
Mass Ejection ◽  
Force Free Field
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