scholarly journals Thermal conduction effects on the kink instability in coronal loops

2010 ◽  
Vol 525 ◽  
pp. A96 ◽  
Author(s):  
G. J. J. Botha ◽  
T. D. Arber ◽  
A. W. Hood
Keyword(s):  
Thermal Conduction ◽  
Coronal Loops ◽  
Kink Instability

scholarly journals ANOMALOUS COOLING OF CORONAL LOOPS WITH TURBULENT SUPPRESSION OF THERMAL CONDUCTION

2016 ◽  
Vol 833 (1) ◽  
pp. 76 ◽  
Author(s):  
Nicolas H. Bian ◽  
Jonathan M. Watters ◽  
Eduard P. Kontar ◽  
A. Gordon Emslie
Keyword(s):  
Thermal Conduction ◽  
Coronal Loops

scholarly journals OBSERVATIONAL SIGNATURES OF THE CORONAL KINK INSTABILITY WITH THERMAL CONDUCTION

2011 ◽  
Vol 745 (1) ◽  
pp. 53 ◽  
Author(s):  
G. J. J. Botha ◽  
T. D. Arber ◽  
Abhishek K. Srivastava
Keyword(s):  
Thermal Conduction ◽  
Kink Instability

scholarly journals Damping of standing slow waves in hot coronal loops

2007 ◽  
Vol 3 (S247) ◽  
pp. 303-311
Author(s):  
Leonardo Di G. Sigalotti ◽  
César A. Mendoza-Briceño ◽  
Marialejandra Luna-Cardozo
Keyword(s):  
Energy Dissipation ◽  
Viscous Dissipation ◽  
Thermal Conduction ◽  
Slow Waves ◽  
Coronal Loops ◽  
Slow Mode ◽  
Decay Times ◽  
Crossing Time ◽  
Linear Limit ◽  
Radiative Losses

AbstractThe damping of standing slow mode oscillations in hot (T > 6 MK) coronal loops is described in the linear limit. The effects of energy dissipation by thermal conduction, viscosity, and radiative losses and gains are examined for both stratified and nonstratified loops. We find that thermal conduction acts on the way of increasing the period of the oscillations over the sound crossing time, whereas the decay times are mostly determined by viscous dissipation. Thermal conduction alone results in slower damping of the density and velocity waves compared to the observations. Only when viscosity is added do these waves damp out at the same rate of the observed SUMER loop oscillations. In the linear limit, the periods and decay times are barely affected by gravity.

scholarly journals Can Resistive Kink Instabilities Drive Simple Loop Flares?

1989 ◽  
Vol 104 (2) ◽  
pp. 305-308
Author(s):  
M. Velli ◽  
G. Emaudi ◽  
A.W. Hood
Keyword(s):  
Magnetic Field ◽  
Boundary Conditions ◽  
Growth Rates ◽  
Axial Magnetic Field ◽  
Small Region ◽  
Coronal Loops ◽  
Simple Loop ◽  
Cylindrically Symmetric ◽  
Line Tying ◽  
Kink Instability

SummaryA detailed analysis of the kink instability in finite length (inertially line-tied), cylindrically symmetric coronal loops is presented. The correct line-tying boundary conditions within the framework of ideal and resistive magnctohydrodynamics are discussed, and the growth rates of unstable modes and corresponding eigenfunctions are calculated. Resistive kink modes are found to be unstable in configurations where the axial magnetic field undergoes an inversion, resistive effects being confined to a small region around the loop vertex.

scholarly journals Numerical simulations of kink instability in line-tied coronal Loops

2001 ◽  
Vol 373 (3) ◽  
pp. 1089-1098 ◽  
Author(s):  
C. L. Gerrard ◽  
T. D. Arber ◽  
A. W. Hood ◽  
R. A. M. Van der Linden
Keyword(s):  
Numerical Simulations ◽  
Coronal Loops ◽  
Kink Instability

scholarly journals Mechanisms for Coronal Mass Supply by Evaporative Micro-Events

2001 ◽  
Vol 203 ◽  
pp. 498-500
Author(s):  
J. C. Brown ◽  
S. Krucker ◽  
M. Güdel ◽  
A. O. Benz
Keyword(s):  
Solar Corona ◽  
Energy Release ◽  
Thermal Conduction ◽  
Major Part ◽  
Coronal Loops ◽  
Transport Mechanisms ◽  
Chromospheric Evaporation

There is extensive evidence from SoHO and other data that “micro-events” play an important role in sustaining at least some components of the solar corona. These are often termed coronal micro-” heating events” though a major part of their role is feeding coronal loops through chromospheric evaporation. We consider what can be learnt from these data concerning the energy release and transport mechanisms driving the evaporation, including thermal conduction and fast particles. We conclude, from one large event and the statistics of many small ones, that conductive evaporation alone does not fit observations and that fast particles or some other nonthermal driver must be involved.

scholarly journals Thermally damped linear compressional waves in a 2D solar coronal model

2007 ◽  
Vol 3 (S247) ◽  
pp. 320-323
Author(s):  
A. Marcu ◽  
I. Ballai ◽  
B. Orza
Keyword(s):  
Thermal Conduction ◽  
Transport Coefficients ◽  
Coronal Loops ◽  
Two Dimensional ◽  
Compressional Waves ◽  
Transversal Motion ◽  
Main Effects ◽  
The Waves ◽  
2D Model ◽  
Coronal Structures

AbstractThe high resolution observations (TRACE and SOHO) of waves in coronal structures have revealed a rapid damping of modes, sometimes their damping length being of the same order as their wavelength. The rapid damping of modes in coronal loops permits us to derive values for magnetic field and transport coefficients. In this contribution we study the damping of linear compressional waves considering a two-dimensional propagation in gravitationally stratified plasma in the presence of thermal conduction. By considering this 2D model, we show that the presence of an additional transversal motion has an important effect on the damping of the waves. This theoretical model allows as to conclude that the main effects influencing the damping of the waves are the degree of the transversal structuring and temperature.

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