Magnetostatic atmospheres with variations in three dimensions

Journal Article · Wed Dec 15 04:00:00 EST 1982 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/160563· OSTI ID:5988416

Low, B C

The paper treats the static equilibrium of a fully ionized atmosphere with an embedded magnetic field in the presence of a uniform gravity. The magnetic field lines are assumed to lie in parallel vertical planes, taken to be perpendicular to the x-axis in Cartesian coordinates. Except for this assumption, the system is allowed to vary in all three dimensions. The theoretical investigation reported here is a departure from previous studies of magnetostatics which have been limited by mathematical tractability to symmetric or two-dimensional systems. The class of three-dimensional equilibria considered are characterized by the sum of plasma and magnetic pressures being invariant in the x-direction. A nonlinear second-order hyperbolic partial differential equation having y and z as independent variables, is shown to be a necessary condition on the magnetic surfaces for an equilibrium state to exist. This is a physical condition not encountered in symmetric equilibria described with an ignorable coordinate. The special case of the total pressure varying only with height is soluble analytically and selected explicit solutions are presented to illustrate various structural properties of prominence-like density enhancements, coronal magnetic arcades, and discrete bipolar plasma loops. There is considerable interest in the equilibrium and stability of plasma loops in the solar corona. This paper presents for the first time, explicit equilibrium solutions for plasma loops with three-dimensional extensions. Of particular interest is that the loop solutions presented include simple examples which can be shown to be stable under isothermal conditions.

• Research Organization: High Altitude Observatory, National Center for Atmospheric Research
• OSTI ID: 5988416
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 263:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640102* -- Astrophysics & Cosmology-- Stars & Quasi-Stellar
Radio & X-Ray Sources
640104 -- Astrophysics & Cosmology-- Solar Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANALYTICAL SOLUTION
ATMOSPHERES
EQUILIBRIUM
FLUID MECHANICS
GRAVITATION
HYDRODYNAMICS
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
PLASMA
SOLAR ACTIVITY
SOLAR ATMOSPHERE
SOLAR PROMINENCES
STAR MODELS
STELLAR ATMOSPHERES
THREE-DIMENSIONAL CALCULATIONS