Nonlinear Parker instability of isolated magnetic flux in a plasma

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

DOI:https://doi.org/10.1086/167212· OSTI ID:6250609

Shibata, K; Tajima, T; Matsumoto, R; Hanawa, T; Horiuchi, T

The nonlinear evolution of the Parker instability in an isolated horizontal magnetic-flux sheet embedded in a two-temperature layer atmosphere is studied by using a two-dimensional MHD code. In the solar case, this two-layer model is regarded as a simplified abstraction of the sun's photosphere/chromosphere and its overlying much hotter (coronal) envelope. The horizontal flux sheet is initially located in the lower temperature atmosphere so as to satisfy magnetostatic equilibrium under a constant gravitational acceleration. Ideal MHD is assumed, and only perturbations with k parallel to the magnetic-field lines are investigated. As the instability develops, the gas slides down the expanding loop, and the evacuated loop rises as a result of enhanced magnetic buoyancy. In the nonlinear regime of the instability, both the rise velocity of a magnetic loop and the local Alfven velocity at the top of the loop increase linearly with height and show self-similar behavior with height as long as the wavelength of the initial perturbation is much smaller than the horizontal size of the computing domain. 76 refs.

• Research Organization: Texas Univ., Austin (USA); Texas, University, Austin; Aichi University of Education, Kariya, Japan; Kyoto University, Japan; Max-Planck-Institut fuer Physik und Astrophysik, Munich, Federal Republic of Germany; Nagoya University, Japan
• OSTI ID: 6250609
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 338; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640104* -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHROMOSPHERE
FLUID MECHANICS
GRAVITATIONAL FIELDS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
INSTABILITY
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
NONLINEAR PROBLEMS
PLASMA
SOLAR ATMOSPHERE
SOLAR CORONA
STABILITY
STELLAR ATMOSPHERES
STELLAR CORONAE
VELOCITY