Dynamics of magnetosphere-ionosphere coupling including turbulent transport

Journal Article · Sat Jan 01 04:00:00 EST 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA088iA01p00365· OSTI ID:6034756

Lysak, R L; Dum, C T

The dynamics of magnetosphere-ionosphere coupling has been investigated by means of a two-dimensional two-fluid MHD model including anomalous resistivity. When field-aligned current is generated on auroral field lines, the disturbance propagates toward the ionosphere in the form of a kinetic Alfven wave. When the current exceeds a critical value, microscopic turbulence is produced, which modifies the propagation of the Alfven wave. This process is modeled by a nonlinear collision frequency, which increases with the excess of the drift velocity over the critical value. The system evolves toward an electrostatic structure, with the perpendicular electric field having a shorter scale than the field-aligned current. The approach to a steady state is strongly dependent on the presence or absence of the turbulence and on the boundary conditions imposed in the generator. As current is increased or scale size is decreased, the turbulent region reflects and absorbs most of the Alfven wave energy, decoupling the generator from the ionosphere.

• Research Organization: Max-Planck-Institut fuer Extraterrestrische Physik, D-8046 Garching, Federal Republic of Germany
• OSTI ID: 6034756
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 88:A1; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
640203 -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
AURORAE
CURRENTS
EARTH ATMOSPHERE
ELECTRIC CURRENTS
ELECTRIC FIELDS
FLUID FLOW
FLUID MECHANICS
HYDRODYNAMICS
HYDROMAGNETIC WAVES
IONOSPHERE
MAGNETOHYDRODYNAMICS
MAGNETOSPHERE
MECHANICS
PLANETARY IONOSPHERES
PLASMA DRIFT
TURBULENT FLOW
TWO-DIMENSIONAL CALCULATIONS