Temporal features of the outflow of heavy ionospheric ions in response to a high altitude plasma cavity

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL016i001p00029· OSTI ID:5622829

Singh, Nagendra; Hwang, K S; Torr, D G; Richards, P ^[1]

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1. Univ. of Alabama, Huntsville (USA)

Using a hydrodynamic model for the plasma, it is demonstrated that the auroral plasma cavity is capable of drawing an appreciably large flux of oxygen ions, which are normally gravitationally bound. This escape mechanism of O{sup +} does not involve any additional heating or acceleration of the plasma in the ionosphere. The temporal evolution of the outflow shows that it starts near the cavity and penetrates into the ionosphere with a flux front moving down with the ion-acoustic speed. A steady outflow is reached in a few hours for a cavity at a height of one R{sub e} if the cavity is maintained. This time reduces to < 1 hour for cavity heights < 3,000 km. During the transient state (< 1 hour) the outflux can appreciably exceed that in the steady state. In view of the horizontal convection, the transient outflow is of special significance. As the cavity descends, the ionospheric flux of O{sup +} ({Gamma}{sub o}{sup +}) increases; for the lower edge of the cavity in the altitude range 3-10 {times} 10{sup 3} km, the steady flux is found to be in the range 10{sup 9} > {Gamma}{sub o}{sup +} (cm{sup {minus}3} s{sup {minus}1}) > 10{sup 7}. An analysis for the steady state shows that outflow is controlled by the density scale height in the cavity.

• OSTI ID: 5622829
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 16:1; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
&amp; Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
ALTITUDE
AURORAL ZONES
CATIONS
CHARGED PARTICLES
CONVECTION
ENERGY TRANSFER
FLUID MECHANICS
HEAT TRANSFER
HYDRODYNAMICS
ION DRIFT
IONS
MASS TRANSFER
MECHANICS
OXYGEN IONS
PLASMA ACCELERATION
PLASMA DENSITY
PLASMA SIMULATION
SIMULATION
STEADY-STATE CONDITIONS