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Title: EXPLOSIVE INSTABILITY AND CORONAL HEATING

Abstract

The observed energy-loss rate from the solar corona implies that the coronal magnetic field has a critical angle at which energy is released. It has been hypothesized that at this critical angle an 'explosive instability' would occur, leading to an enhanced conversion of magnetic energy into heat. In earlier investigations, we have shown that a shear-dependent magnetohydrodynamic process called 'secondary instability' has many of the distinctive features of the hypothetical 'explosive instability'. In this paper, we give the first demonstration that this 'secondary instability' occurs in a system with line-tied magnetic fields and boundary shearing-basically the situation described by Parker. We also show that, as the disturbance due to secondary instability attains finite amplitude, there is a transition to turbulence which leads to enhanced dissipation of magnetic and kinetic energy. These results are obtained from numerical simulations performed with a new parallelized, viscoresistive, three-dimensional code that solves the cold plasma equations. The code employs a Fourier collocation-finite difference spatial discretization, and uses a third-order Runge-Kutta temporal discretization.

Authors:
;  [1]; ;  [2]
  1. Laboratory for Computational Physics and Fluid Dynamics, Naval Research Laboratory, Washington, DC 20375-5344 (United States)
  2. Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States)
Publication Date:
OSTI Identifier:
21367361
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 704; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/704/2/1059
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; COLD PLASMA; COMPUTERIZED SIMULATION; ENERGY LOSSES; EQUATIONS; EXPLOSIVE INSTABILITY; KINETIC ENERGY; MAGNETIC FIELDS; MAGNETOHYDRODYNAMICS; SOLAR CORONA; SUN; THREE-DIMENSIONAL CALCULATIONS; TURBULENCE; ATMOSPHERES; ENERGY; FLUID MECHANICS; HYDRODYNAMICS; INSTABILITY; LOSSES; MAIN SEQUENCE STARS; MECHANICS; PLASMA; PLASMA INSTABILITY; SIMULATION; SOLAR ATMOSPHERE; STARS; STELLAR ATMOSPHERES; STELLAR CORONAE

Citation Formats

Dahlburg, R. B., Liu, J.-H., Klimchuk, J. A., and Nigro, G., E-mail: rdahlbur@lcp.nrl.navy.mi. EXPLOSIVE INSTABILITY AND CORONAL HEATING. United States: N. p., 2009. Web. doi:10.1088/0004-637X/704/2/1059.
Dahlburg, R. B., Liu, J.-H., Klimchuk, J. A., & Nigro, G., E-mail: rdahlbur@lcp.nrl.navy.mi. EXPLOSIVE INSTABILITY AND CORONAL HEATING. United States. doi:10.1088/0004-637X/704/2/1059.
Dahlburg, R. B., Liu, J.-H., Klimchuk, J. A., and Nigro, G., E-mail: rdahlbur@lcp.nrl.navy.mi. Tue . "EXPLOSIVE INSTABILITY AND CORONAL HEATING". United States. doi:10.1088/0004-637X/704/2/1059.
@article{osti_21367361,
title = {EXPLOSIVE INSTABILITY AND CORONAL HEATING},
author = {Dahlburg, R. B. and Liu, J.-H. and Klimchuk, J. A. and Nigro, G., E-mail: rdahlbur@lcp.nrl.navy.mi},
abstractNote = {The observed energy-loss rate from the solar corona implies that the coronal magnetic field has a critical angle at which energy is released. It has been hypothesized that at this critical angle an 'explosive instability' would occur, leading to an enhanced conversion of magnetic energy into heat. In earlier investigations, we have shown that a shear-dependent magnetohydrodynamic process called 'secondary instability' has many of the distinctive features of the hypothetical 'explosive instability'. In this paper, we give the first demonstration that this 'secondary instability' occurs in a system with line-tied magnetic fields and boundary shearing-basically the situation described by Parker. We also show that, as the disturbance due to secondary instability attains finite amplitude, there is a transition to turbulence which leads to enhanced dissipation of magnetic and kinetic energy. These results are obtained from numerical simulations performed with a new parallelized, viscoresistive, three-dimensional code that solves the cold plasma equations. The code employs a Fourier collocation-finite difference spatial discretization, and uses a third-order Runge-Kutta temporal discretization.},
doi = {10.1088/0004-637X/704/2/1059},
journal = {Astrophysical Journal},
number = 2,
volume = 704,
place = {United States},
year = {Tue Oct 20 00:00:00 EDT 2009},
month = {Tue Oct 20 00:00:00 EDT 2009}
}
  • Ion heating by the explosive instability in an ion beam--plasma system is studied theoretically. Two electrostatic waves with negative and positive energies become simultaneously unstable by nonlinear wave--particle interaction (nonlinear Landau damping) with plasma ions accompanying ion heating. The relaxation of the ion beam makes the explosion time of the waves much larger and causes saturation of the ion heating. It is shown quantitatively that the decrement of beam energy is transferred into thermal energies of plasma and beam ions by this explosive instability.
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