Solar magneto-atmospheric waves. I. An exact solution for a horizontal magnetic field

Journal Article · Mon Mar 01 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154205· OSTI ID:7282319

Nye, A H; Thomas, J H

The linearized theory of magneto-atmospheric waves (involving the combined restoring forces due to buoyancy, compressibility, and magnetic field) is developed for the case of a horizontal magnetic field. A general propagation equation is derived for adiabatic perturbations with arbitrary vertical distributions of the sound speed c, Alfven velocity v/subA/, and local density scale height H. An exact analytical solution to the propagation equation is obtained for the case of an isothermal atmosphere permeated by a uniform horizontal magnetic field, without making the usual short-wavelength assumption. This solution is applied to an idealized model of the low-corona--chromosphere transition region for comparison with observations of flare-induced coronal waves. The results show that disturbances may propagate horizontally in the low corona in a wave guide formed by the sudden density increase into the chromosphere below and by the rapidly increasing Alfven velocity with height in the corona. The group velocity of the guided wave modes is nearly independent of wavelength, so that a disturbance propagates as a compact wave packet. (AIP)

• Research Organization: Department of Mechanical and Aerospace Sciences, University of Rochester
• OSTI ID: 7282319
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 204:2; 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
DENSITY
DISTURBANCES
HYDROMAGNETIC WAVES
MAGNETIC FIELDS
PHYSICAL PROPERTIES
SOLAR ATMOSPHERE
SOLAR CORONA
WAVE PROPAGATION