Two-stream modeling of plasmaspheric refilling

Technical Report · Thu Jun 01 04:00:00 EDT 1995

OSTI ID:200629

Guiter, S M; Gombosi, T I; Rasmussen, C E

Plasmaspheric refilling on an L = 4 flux tube was studied by using a time-dependent, hydrodynamic plasmaspheric flow model in which the ion streams from the two hemispheres are treated as distinct fluids. In the model the continuity, momentum, and energy equations of a two-ion (O(+) and H(+)), quasi-neutral, currentless plasma are solved along a closed geomagnetic field line; diffusive equilibrium is not assumed. Collisions between all stream pairs and with neutral species are included. The model includes a corotating, tilted dipole magnetic field and neutral winds. Ionospheric sources and sinks are accounted for in a self-consistent manner. Electrons are assumed to be heated by photoelectrons. The model flux tube extends from a 200-km altitude in one hemisphere to a 200-km altitude in the other hemisphere. Initially, the upwelling streams pass through each other practically unimpeded. When the streams approach the boundary in the conjugate ionosphere, a shock develops there, which moves upward and dissipates slowly; at about the same time a reverse shock develops in the hemisphere of origin, which moves upward. After about 1 hour, large shocks develop in each stream near the equator; these shocks move toward the equator and downward after crossing the equator. However, these shocks are probably artificial, because counterstreaming flows occur in each H(+) fluid, which the model can only handle by creating shocks.

• Research Organization: National Aeronautics and Space Administration, Huntsville, AL (United States). George C. Marshall Space Flight Center
• OSTI ID: 200629
• Report Number(s): N--96-19523; NASA-CR--199997; NAS--1.26:199997; NIPS--96-07100; CNN: NGT-50368; NAGW-1619; NSF ATM-91-16858
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRIC POTENTIAL
HYDRODYNAMICS
HYDROGEN IONS
ION DRIFT
KINETIC ENERGY
MAGNETIC FIELDS
MAGNETIC FLUX
OXYGEN IONS
PLASMA FLUID EQUATIONS
PLASMASPHERE
SHOCK WAVES