Studies on Equatorial Shock Formation During Plasmaspheric Refilling. Final report, 1 August 1994-31 October 1995

Technical Report · Sun Oct 01 04:00:00 EDT 1995

OSTI ID:236813

Singh, N

During the grant period from August 1, 1994 to October 31, 1995 the authors have continued to investigate the effects of plasma wave instabilities on the early stage plasmaspheric refilling. Since ion beams are the primary feature of the interhemispheric plasma flows during the early stage refilling, ion-beam driven instabilities and associated waves are of primary interest. The major findings of this research are briefly summarized here. After a systematic examination of the relevant plasma instabilities, the authors realized that when the interhemispheric plasma flows begin to interpenetrate at the equator, the most relevant plasma instability is the electrostatic ion cyclotron wave instability. Only at later stages the ion-acoustic instability may be affecting the plasma flow. An interesting property of the electrostatic ion cyclotron wave is that it heats ions perpendicular to the magnetic field. When the ions in the field-aligned flows are transversely heated, they are trapped in the magnetic flux tube, thus affecting the refilling process. The eic wave instability is a microprocess with scale length of the order of ion Larmor radius and the corresponding time scale is the ion cyclotron period. The authors have attempted to tackle the problem for the plasmaspheric refilling by incorporating the effects of eic wave instability on the mesoscale plasma flow when the properties of the latter exceeds the critical conditions for the former. They have compared the results on refilling from the model with and without the eic instability effects.

• Research Organization: Alabama Univ., Huntsville, AL (United States)
• OSTI ID: 236813
• Report Number(s): N--96-22865; NASA-CR--200752; NAS--1.26:200752; NIPS--96-39336; CNN: NAGW-2128; NSF ATM-93-01024
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CYCLOTRON INSTABILITY
ION BEAMS
LARMOR RADIUS
MAGNETIC FLUX
PLASMA DRIFT
PLASMA WAVES
PLASMASPHERE
PROGRESS REPORT