On hot tenuous plasmas, fireballs, and boundary layers in the earth's magnetotail

Journal Article · Wed Dec 01 04:00:00 EST 1976 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA081i034p05859· OSTI ID:7236578

Frank, L A; Ackerson, K L; Lepping, R P

Intensive correlative studies of magnetic fields and plasmas within the earth's magnetotail at geocentric radial distances of approx. 23--46 R/sub E/ during March--October 1974 revealed striking new features. The hot tenuous plasmas within the plasma sheet were found to be in a state of almost continual flow and were threaded with northward, or closed, geomagnetic field lines. Proton bulk speeds were in the range 50--500 km s/sup -1/. The magnetic fields are directed northward. These observations demand a strong persistent source of magnetic flux and hot plasmas for the plasma sheet. No characteristic proton bulk flows were evident during crossings of the neutral sheet. Occasionally, the satellite encountered the region of acceleration in the magnetotail, the 'fireball.' This spectacular phenomenon exhibits strong jetting of plasmas in exces of 1000 km s/sup -1/, proton temperatures of approx. 10/sup 7/ degreeK (kT approx. 1 keV), disordered magnetic fields, southward magnetic fields during tailward jetting of the plasmas. Earthward plasma flows within the fireball are threaded with closed geomagnetic field lines, and open magnetic field lines are embedded in the tailward jetting plasmas. The magnetosheathlike plasmas within the boundary layers which are positioned contiguous to the plasma sheet display striking evidences of plasma heating, great changes in bulk flow velocities and acceleration of energetic electrons with E > 45 keV. Persistent zones of southward magnetic fields are detected, which are often positioned adjacent to the plasma sheet and within the boundary layer plasmas. Rotations of the magnetic fields from southward to northward, or vice versa, in these boundary layers are accompanied by large enhancements of energetic electron intensities, substantial heating of the low-energy electron distributions, and strong perturbations of the proton velocity distribution functions.(AIP)

• Research Organization: Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242
• OSTI ID: 7236578
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 81:34; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BOUNDARY LAYERS
ELECTRON TEMPERATURE
HEATING
HOT PLASMA
LAYERS
MAGNETIC FIELD CONFIGURATIONS
MAGNETIC FIELDS
MAGNETOTAIL
PLASMA
PLASMA DRIFT
PLASMA HEATING
PLASMA SHEET
PROTON TEMPERATURE