Critical conditions for magnetic instabilities in force-free coronal loops

A. W. Hood; E. R. Priest

doi:10.1080/03091928108243687

Critical conditions for magnetic instabilities in force-free coronal loops

A. W. Hood, E. R. Priest

Applied Mathematics

Research output: Contribution to journal › Article › peer-review

234 Citations (Scopus)

Abstract

Ideal MHD stability theory is studied in order to gain an understanding of the effect of line-tying on an ideal MHD plasma before adding further complexities, and necessary and sufficient conditions are derived for the stability of force-free magnetic loops in the solar corona. The force-free basic state is discussed, and linear stability equations are derived. Attention is given to the boundary conditions used to simulate the line-tying effect of the dense photosphere. A very simple field structure is used to solve the stability equations analytically, the stability conditions obtained being verified by the energy principle. A method is presented for finding the stability of a general, cylindrically symmetric, force-free field, and results of an example are compared with the previous bounds obtained by Hood and Priest (1979, 1980).

Original language	English
Pages (from-to)	297-318
Journal	Geophysical and Astrophysical Fluid Dynamics
Volume	17
DOIs	https://doi.org/10.1080/03091928108243687
Publication status	Published - 1981

Keywords

Coronal Loops
Force-Free Magnetic Fields
Magnetohydrodynamic Stability
Solar Corona
Solar Magnetic Field
Boundary Conditions
Boundary Value Problems
Linear Equations
Magnetic Field Configurations
Mathematical Models
Photosphere

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10.1080/03091928108243687

http://adsabs.harvard.edu/abs/1981GApFD..17..297H

Cite this

@article{211aea9ced2c4c3a8a506343fdb3ee5a,

title = "Critical conditions for magnetic instabilities in force-free coronal loops",

abstract = "Ideal MHD stability theory is studied in order to gain an understanding of the effect of line-tying on an ideal MHD plasma before adding further complexities, and necessary and sufficient conditions are derived for the stability of force-free magnetic loops in the solar corona. The force-free basic state is discussed, and linear stability equations are derived. Attention is given to the boundary conditions used to simulate the line-tying effect of the dense photosphere. A very simple field structure is used to solve the stability equations analytically, the stability conditions obtained being verified by the energy principle. A method is presented for finding the stability of a general, cylindrically symmetric, force-free field, and results of an example are compared with the previous bounds obtained by Hood and Priest (1979, 1980).",

keywords = "Coronal Loops, Force-Free Magnetic Fields, Magnetohydrodynamic Stability, Solar Corona, Solar Magnetic Field, Boundary Conditions, Boundary Value Problems, Linear Equations, Magnetic Field Configurations, Mathematical Models, Photosphere",

author = "Hood, {A. W.} and Priest, {E. R.}",

year = "1981",

doi = "10.1080/03091928108243687",

language = "English",

volume = "17",

pages = "297--318",

journal = "Geophysical and Astrophysical Fluid Dynamics",

issn = "0309-1929",

publisher = "Taylor and Francis",

}

TY - JOUR

T1 - Critical conditions for magnetic instabilities in force-free coronal loops

AU - Hood, A. W.

AU - Priest, E. R.

PY - 1981

Y1 - 1981

N2 - Ideal MHD stability theory is studied in order to gain an understanding of the effect of line-tying on an ideal MHD plasma before adding further complexities, and necessary and sufficient conditions are derived for the stability of force-free magnetic loops in the solar corona. The force-free basic state is discussed, and linear stability equations are derived. Attention is given to the boundary conditions used to simulate the line-tying effect of the dense photosphere. A very simple field structure is used to solve the stability equations analytically, the stability conditions obtained being verified by the energy principle. A method is presented for finding the stability of a general, cylindrically symmetric, force-free field, and results of an example are compared with the previous bounds obtained by Hood and Priest (1979, 1980).

AB - Ideal MHD stability theory is studied in order to gain an understanding of the effect of line-tying on an ideal MHD plasma before adding further complexities, and necessary and sufficient conditions are derived for the stability of force-free magnetic loops in the solar corona. The force-free basic state is discussed, and linear stability equations are derived. Attention is given to the boundary conditions used to simulate the line-tying effect of the dense photosphere. A very simple field structure is used to solve the stability equations analytically, the stability conditions obtained being verified by the energy principle. A method is presented for finding the stability of a general, cylindrically symmetric, force-free field, and results of an example are compared with the previous bounds obtained by Hood and Priest (1979, 1980).

KW - Coronal Loops

KW - Force-Free Magnetic Fields

KW - Magnetohydrodynamic Stability

KW - Solar Corona

KW - Solar Magnetic Field

KW - Boundary Conditions

KW - Boundary Value Problems

KW - Linear Equations

KW - Magnetic Field Configurations

KW - Mathematical Models

KW - Photosphere

U2 - 10.1080/03091928108243687

DO - 10.1080/03091928108243687

M3 - Article

SN - 0309-1929

VL - 17

SP - 297

EP - 318

JO - Geophysical and Astrophysical Fluid Dynamics

JF - Geophysical and Astrophysical Fluid Dynamics

ER -

Critical conditions for magnetic instabilities in force-free coronal loops

Abstract

Keywords

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