Magnetohydrodynamic instabilities in coronal arcades

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/167170· OSTI ID:5899311

An, Chang-Hyuk; Wu, S T; Suess, S T

The MHD stability of coronal arcades is studied with and without a detached flux using a two-dimensional linear MHD stability numerical model. Two-dimensional magnetohydrostatic equilibria with and without gravity are computed. A coronal arcade without a detached flux tube is found to be stable for any magnetic shear and for any longitudinal mode. On the other hand, an arcade with a detached flux tube is unstable for perturbations with nonzero longitudinal wave number n and the instability mode structure and growth rate vary depending on the field twist and n. All the equilibria studied are stable to n = 0 perturbations. Gravity has a stabilizing effect on the equilibria. As the ratio lambda of the standard arcade width to the gravitational scale height increases from zero to 0.2, the m = 0 transverse mode growth rate decreases, but high m modes are stabilized. The equilibria studied here are completely stabilized for lambda larger than 0.33. 25 references.

• Research Organization: Alabama Univ., Huntsville (USA); Alabama Univ., Huntsville (USA)
• OSTI ID: 5899311
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 337; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
FLUID MECHANICS
GRAVITATIONAL FIELDS
HYDRODYNAMICS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
PERTURBATION THEORY
SHEAR
SOLAR ATMOSPHERE
SOLAR CORONA
STABILITY
STELLAR ATMOSPHERES
STELLAR CORONAE
TWO-DIMENSIONAL CALCULATIONS
VELOCITY