Fast Magnetic Reconnection by Turbulence with High Landquist Number

2020 ◽  
Author(s):  
Liping Yang ◽  
Hui Li ◽  
Fan Guo ◽  
Xiancan Li ◽  
Shengtai Li ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Energy Release ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Turbulent Plasma ◽  
Turbulence Level ◽  
Reconnection Rate ◽  
Numerical Studies ◽  
Large Opening ◽  
Magnetic Energy Release

<p>We report detailed numerical studies of magnetic reconnection in high-Lundquist-number, turbulent plasma by means of a three-dimensional (3D) resistive magnetohydrodynamics model. It is found that although turbulence is pre-existing, magnetic fields still restructure themselves to shape many X-points with evident mean inflow/outflow as well as the hierarchically generated magnetic flux ropes (plasmoids in 2D) with twist field lines. Moreover, the turbulence facilitates magnetic reconnections, and makes the normalized global reconnection rate reach ∼ 0.02 − 0.1, corresponding to turbulence level from very low to high and magnetic energy release from feeble to violent. The rate is nearly independent on the Lundquist number, and thus the fast turbulent reconnection occurs. A stochastic separation of the reconnected magnetic field lines with large opening angles follows a super-diffusion, indicating the broadening of outflow regions owing to the turbulence. These findings manifest that with the high Lundquist numbers (S ≥ 10^4), the 3D reconnection is turbulent and fast.</p>

scholarly journals Magnetic Energy Release, Plasma Dynamics, and Particle Acceleration in Relativistic Turbulent Magnetic Reconnection

2021 ◽  
Vol 919 (2) ◽  
pp. 111
Author(s):  
Fan Guo ◽  
Xiaocan Li ◽  
William Daughton ◽  
Hui Li ◽  
Patrick Kilian ◽  
...  
Keyword(s):  
Particle Acceleration ◽  
Magnetic Reconnection ◽  
Energy Release ◽  
Magnetic Energy ◽  
Plasma Dynamics ◽  
Magnetic Energy Release

Magnetic Energy Release and Transients in the Solar Flare of 2000 July 14

2001 ◽  
Vol 550 (1) ◽  
pp. L105-L108 ◽  
Author(s):  
A. G. Kosovichev ◽  
V. V. Zharkova
Keyword(s):  
Solar Flare ◽  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

scholarly journals Three-dimensional magnetic reconnection and its application to solar flares

2017 ◽  
Vol 83 (1) ◽  
Author(s):  
Miho Janvier
Keyword(s):  
Kinetic Energy ◽  
Numerical Simulations ◽  
Magnetic Reconnection ◽  
Solar Flares ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Three Dimensions ◽  
Current Layer ◽  
Solar Observations ◽  
The Universe

Solar flares are powerful radiations occurring in the Sun’s atmosphere. They are powered by magnetic reconnection, a phenomenon that can convert magnetic energy into other forms of energy such as heat and kinetic energy, and which is believed to be ubiquitous in the universe. With the ever increasing spatial and temporal resolutions of solar observations, as well as numerical simulations benefiting from increasing computer power, we can now probe into the nature and the characteristics of magnetic reconnection in three dimensions to better understand the phenomenon’s consequences during eruptive flares in our star’s atmosphere. We review in the following the efforts made on different fronts to approach the problem of magnetic reconnection. In particular, we will see how understanding the magnetic topology in three dimensions helps in locating the most probable regions for reconnection to occur, how the current layer evolves in three dimensions and how reconnection leads to the formation of flux ropes, plasmoids and flaring loops.

scholarly journals Magnetic Energy Release in Dynamic Fan Reconnection Models

1999 ◽  
Vol 510 (2) ◽  
pp. 1045-1052 ◽  
Author(s):  
I. J. D. Craig ◽  
A. N. McClymont
Keyword(s):  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

scholarly journals Scaling of magnetic reconnection with a limited x-line extent

2021 ◽  
Author(s):  
Kai Huang ◽  
Yi-Hsin Liu ◽  
Quanming Lu ◽  
Michael Hesse
Keyword(s):  
Magnetic Reconnection ◽  
Magnetic Energy ◽  
Well Being ◽  
Reconnection Rate ◽  
Flux Transport ◽  
Speed Reduction ◽  
Reconnection Region ◽  
Line Asymmetry ◽  
Fundamental Physical ◽  
Suppression Region

<p>Magnetic reconnection is a fundamental physical process that is responsible for releasing the magnetic energy during substorms of planetary magnetotails. Previous studies of magnetic reconnection usually take the two-dimensional (2D) approach, which assumes that reconnection is uniform in the 3rd direction out of the 2D reconnection plane. However, observations suggest that reconnection can be limited in the 3rd direction, such as reconnection at Mercury's magnetotail. It turns out that reconnection can be suppressed when reconnection region is very limited in the 3rd direction. An internal x-line asymmetry along the current direction develops because of the transport of reconnected magnetic flux by electrons beneath the ion kinetic scale, resulting in a suppression region identified in Liu et al., 2019. Under the guidance of a series of 3D kinetic simulations, in this work, we incorporate the length-scale of this suppression region ~10d<sub>i</sub> to quantitatively model the reduction of the reconnection rate and the maximum outflow speed observed in the short x-line limit. The average reconnection rate drops because of the limited active region (where the current sheet thins down to the electron inertial scale) within an x-line. The outflow speed reduction correlates with the decrease of the <strong>J</strong>×<strong>B</strong> force, that can be modeled by the phase shift between the <strong>J</strong> and <strong>B</strong> profiles, also as a consequence of the flux transport. Notably, these two quantities are most essential in defining the well-being of magnetic reconnection, which can tell us when reconnection shall be suppressed.</p>

scholarly journals Large polar caps for twisted magnetosphere of magnetars

2019 ◽  
Author(s):  
H Tong
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Energy Release ◽  
Open Field ◽  
Magnetic Energy ◽  
Hot Spot ◽  
Open Field Line ◽  
Field Lines ◽  
The Magnetic Field ◽  
Magnetic Energy Release

Abstract The magnetic field of magnetars may be twisted compared with that of normal pulsars. Previous works mainly discussed magnetic energy release in the closed field line regions of magnetars. For a twisted magnetic field, the field lines will inflate in the radial direction. Similar to normal pulsars, the idea of light cylinder radius is introduced. More field lines will cross the light cylinder and become open for a twisted magnetic field. Therefore, magnetars may have a large polar cap, which may correspond to the hot spot during outburst. Particle flow in the open field line regions will result in the untwisting of the magnetic field. Magnetic energy release in the open field line regions can be calculated. The model calculations can catch the general trend of magnetar outburst: decreasing X-ray luminosity, shrinking hot spot etc. For magnetic energy release in the open field line regions, the geometry will be the same for different outburst in one magnetar.

Turbulent impulsive magnetic energy release from electron scale reconnection

2007 ◽  
Vol 14 (1) ◽  
pp. 012902 ◽  
Author(s):  
W. Horton ◽  
J.-H. Kim ◽  
F. Militello ◽  
M. Ottaviani
Keyword(s):  
Energy Release ◽  
Magnetic Energy ◽  
Magnetic Energy Release

scholarly journals Magnetic energy release: flares and coronal mass ejections

2009 ◽  
Vol 5 (S264) ◽  
pp. 257-266 ◽  
Author(s):  
Cristina H. Mandrini
Keyword(s):  
Magnetic Field ◽  
Energy Release ◽  
Coronal Mass Ejections ◽  
Magnetic Energy ◽  
Radiative Energy ◽  
Electromagnetic Spectrum ◽  
Combined Analysis ◽  
Magnetic Field Topology ◽  
The Magnetic Field ◽  
Magnetic Energy Release

AbstractFree energy stored in the magnetic field is the source that powers solar and stellar activity at all temporal and spatial scales. The energy released during transient atmospheric events is contained in current-carrying magnetic fields that have emerged twisted and may be further stressed via motions in the lower atmospheric layers (i.e. loop-footpoint motions). Magnetic reconnection is thought to be the mechanism through which the stored magnetic energy is transformed into kinetic energy of accelerated particles and mass flows, and radiative energy along the whole electromagnetic spectrum. This mechanism works efficiently at scale lengths much below the spatial resolution of even the highest resolution solar instruments; however, it may imply a large-scale restructuring of the magnetic field inferred indirectly from the combined analysis of observations and models of the magnetic field topology. The aftermath of magnetic energy release includes events ranging from nanoflares, which are below our detection limit, to powerful flares, which may be accompanied by the ejection of large amounts of plasma and magnetic field (so called coronal mass ejections, CMEs), depending on the amount of total available free magnetic energy, the magnetic flux density distribution, the magnetic field configuration, etc. We describe key observational signatures of flares and CMEs on the Sun, their magnetic field topology, and discuss how the combined analysis of solar and interplanetary observations can be used to constrain the flare/CME ejection mechanism.

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