Effect of Sheared Flow on Resistive Tearing Instability and the Triggering of Flare

AbstractThe nonlinear evolution of tearing modes in the presence of sheared mass flow is studied in the cylindrical geometry. It is demonstrated that a sufficient large sheared mass flow can destabilize the development of resistive tearing instability. It is suggested that the coupling of sheared mass flow with shear magnetic field may be a triggering of solar flares.

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Forced reconnexion by fast magnetosonic waves in a current sheet with stagnation-point flows

Journal of Plasma Physics ◽

10.1017/s0022377800001033 ◽

1983 ◽

Vol 30 (1) ◽

pp. 109-124 ◽

Cited By ~ 12

Author(s):

Jun-Ichi Sakai

Keyword(s):

Current Sheet ◽

Stagnation Point ◽

Solar Flares ◽

Ponderomotive Force ◽

Magnetosonic Wave ◽

Fast Wave ◽

Tearing Mode ◽

Tearing Modes ◽

Tearing Instability ◽

A Current

Forced reconnexion due to tearing modes driven by fast magnetosonic waves in a current sheet with stagnation-point flows is discussed. The current sheet with stagnation-point flows which is weakly unstable against tearing modes can be strongly destabilized by vortex motions due to the ponderomotive force of the fast magnetosonic wave. This forced tearing instability can be driven when the incident fast magnetosonic wave intensity, I, exceeds a critical value given by where is the Alfvén velocity, vg the group velocity of the fast wave, vo the background inflow velocity, l the thickness of the current sheet and k the wavenumber of the forced tearing mode. The growth rate is estimated. Applications to solar flares and magnetopause reconnexion processes are briefly discussed.

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Abrupt Changes of the Photospheric Magnetic Field in Active Regions and the Impulsive Phase of Solar Flares (Preprint)

10.21236/ada566133 ◽

2012 ◽

Author(s):

E. W. Cliver ◽

G. J. Petrie ◽

A. G. Ling

Keyword(s):

Magnetic Field ◽

Solar Flares ◽

Active Regions ◽

Impulsive Phase ◽

Photospheric Magnetic Field ◽

Abrupt Changes

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Effects of plasma turbulence on the nonlinear evolution of magnetic island in tokamak

Nature Communications ◽

10.1038/s41467-020-20652-9 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Minjun J. Choi ◽

Lāszlo Bardōczi ◽

Jae-Min Kwon ◽

T. S. Hahm ◽

Hyeon K. Park ◽

...

Keyword(s):

Magnetic Field ◽

Nonlinear Evolution ◽

Plasma Turbulence ◽

Magnetized Plasmas ◽

Tokamak Plasmas ◽

Magnetic Islands ◽

Magnetic Island ◽

Reconnection Site ◽

Ambient Turbulence

AbstractMagnetic islands (MIs), resulting from a magnetic field reconnection, are ubiquitous structures in magnetized plasmas. In tokamak plasmas, recent researches suggested that the interaction between an MI and ambient turbulence can be important for the nonlinear MI evolution, but a lack of detailed experimental observations and analyses has prevented further understanding. Here, we provide comprehensive observations such as turbulence spreading into an MI and turbulence enhancement at the reconnection site, elucidating intricate effects of plasma turbulence on the nonlinear MI evolution.

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Thermal Trigger for Solar Flares II: Effect of the Guide Magnetic Field

Solar Physics ◽

10.1007/s11207-021-01840-2 ◽

2021 ◽

Vol 296 (6) ◽

Author(s):

Leonid Ledentsov

Keyword(s):

Magnetic Field ◽

Solar Flares ◽

Guide Magnetic Field

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Nonlinear evolution of a wave packet propagating along a hot magnetoplasma column

Journal of Plasma Physics ◽

10.1017/s0022377800012022 ◽

1987 ◽

Vol 37 (1) ◽

pp. 107-115

Author(s):

B. Ghosh ◽

K. P. Das

Keyword(s):

Magnetic Field ◽

Multiple Scales ◽

Nonlinear Evolution ◽

Axial Magnetic Field ◽

Modulational Instability ◽

Wave Train ◽

Dielectric Medium ◽

Ion Effects ◽

The Magnetic Field ◽

Uniform Plasma

The method of multiple scales is used to derive a nonlinear Schrödinger equation, which describes the nonlinear evolution of electron plasma ‘slow waves’ propagating along a hot cylindrical plasma column, surrounded by a dielectric medium and immersed in an essentially infinite axial magnetic field. The temperature is included as well as mobile ion effects for ail possible modes of propagation along the magnetic field. From this equation the condition for modulational instability for a uniform plasma wave train is determined.

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