Cleft contribution to ring current formation

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA12p20937· OSTI ID:5222750

Delcourt, D C ^[1]; Sauvaud, J A ^[2]; Moore, T E ^[3]

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1. European Space Research and Technology Center, Noordwijk (Netherlands)
2. Centre National de la Recherche Scientifique, Toulouse (France)
3. NASA Marshall Space Flight Center, Huntsville, AL (USA)

The storm time transport of ionospheric plasma from the cleft fountain to the plasma sheet and ring current is investigated by means of three-dimensional trajectory codes. Using observations to define the source location and flow rate. The authors trace test particles during a taillike to dipolelike reconfiguration of the geomagnetic field. Emphasis is placed on the behavior of heavy ions of low charge state (O{sup +}). As a result of their long periods of gyration, these ions are highly sensitive to rapid field variations and possible display transient nonadiabatic motions. It is demonstrated that O{sup +} which have originated in the high-latitude ionosphere but which find themselves in the vicinity of the equator at substorm onset can experience considerable erergization (from several keV up to several hundred keV) and pitch angle increase leading to trapping, as an effect of the induced electric field. These effects accompany a rapid earthward transport from midtail ({approximately}10-15 R{sub E}) to geosynchronous altitudes. The average particle energy and density involved suggest a substantial contribution of the cleft O{sup +} fountain to the ring current during substorms.

• OSTI ID: 5222750
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:A12; 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
CHARGED PARTICLES
COMPUTER CODES
CURRENTS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CURRENTS
GEOMAGNETIC FIELD
HEAVY IONS
IONOSPHERE
IONS
MAGNETIC BAYS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
OXYGEN IONS
PLANETARY IONOSPHERES
PLASMA DRIFT
PLASMA SHEET
POLAR CUSP
POLAR REGIONS
TEST PARTICLES
TRAPPING