Plasma cloud expansion in the ionosphere: Three-dimensional simulation

Journal Article · Mon Apr 01 04:00:00 EST 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JA02618· OSTI ID:5223174

Ma, T Z; Schunk, R W ^[1]

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1. Utah State Univ., Logan (USA)

A three-dimensional time-dependent model was developed to study the characteristics of a plasma cloud expansion in the ionosphere. The electrostatic potential is solved in three dimensions taking into account the large parallel-to-perpendicular conductivity ratio. Three sample simulations are presented: a plasma expansion of a nearly spherical 1 km Ba{sup +} cloud, both with and without a background neutral wind, and a long thin Ba{sup +} cloudlet. With or without the neutral wind the effective potential, which is different from the electrostatic potential if the electron temperature is included, is constant along the magnetic field for typical cloud sizes. The expanding plasma clouds become elongated in the magnetic field direction. The released Ba{sup +} ions push the background O{sup +} ions away along the magnetic field as they expand. Consequently, a hole develops in the background O{sup +} distribution at the cloud location and on the two sides of the cloud O{sup +} bumps form. The entire three-dimensional structure, composed of the plasma cloud and the background plasma embedded in the cloud, slowly rotates about the magnetic field, with the ions and electrons rotating in opposite directions. The cloud configuration takes the shape of a rotating ellipsoid with a major axis that expands with time. Perpendicular to the magnetic field, in the absence of the neutral wind the motion is insignificant compared to the parallel motion. With a neutral wind the motion along the magnetic field and the rotational motion are qualitatively unchanged, but the cloud and the perturbed background structure move in the direction of the wind, with a speed less than the wind speed. Perpendicular to the magnetic field the deformation of the cloud indiced by the wind is characterized by steepening of the backside.

• OSTI ID: 5223174
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BARIUM IONS
CHARGED PARTICLES
EARTH ATMOSPHERE
ELECTRIC CONDUCTIVITY
ELECTRIC POTENTIAL
ELECTRICAL PROPERTIES
ELECTRON TEMPERATURE
EXPANSION
IONOSPHERE
IONS
MAGNETIC FIELDS
MATHEMATICAL MODELS
MORPHOLOGY
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
PLASMA EXPANSION
THREE-DIMENSIONAL CALCULATIONS
TIME DEPENDENCE
WIND