Energetic particles in the predawn magnetotail of Jupiter

Journal Article · Wed Sep 30 04:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA086iA10p08413· OSTI ID:5567071

Schardt, A W; McDonald, F B; Trainor, J H

A detailed account is given of the energetic electron and proton populations as observed with Voyager 1 and 2 during their passes through the dawn magnetotail of Jupiter. In general, the results of the Pioneer 10 pass at 90/sup 0/ to the Jupiter-sun line have been confirmed and extended. The region between 20 and 150 R/sub J/ is dominated by a thin plasma sheet, and open field lines were observed at 42 R/sub J/ at a magnetic latitude of only 15/sup 0/. Trapped energetic electron and proton fluxes reach their maximum in the plasma sheet and decrease rapidly even a few degrees away from it. The spectra of trapped protons can be represented by an exponential in rigidity and have a characteristic energy of approx.50 keV. Proton anisotropies in the plasma sheet were consistent with corotation even at 100 R/sub J/, but the preliminary analysis is not yet conclusive. A major proton acceleration event and several cases of field-aligned proton streaming were observed. Comparable proton fluxes were observed in the plasma sheet by Voyager 1 and 2. The flux of >0.4-MeV protons decreases by 3 order of magnitude between 20 and 90 R/sub J/ and then remains relatively constant from there to the boundary layer near the magnetopause. Between 20 and 30 R/sub J/ in the antisolar direction, the trapping region has a latitudinal extent which is comparable to that observed during the inbound pass at -30/sup 0/ solar aspect. The plasma sheet positions in the magnetotail can be represented by a distorted disk which rotates about the Jovian spin axis. Fine structure in the data indicates longitudinal asymmetries with respect to the dipole orientation. Electron spectra in the outer magnetosphere, the magnetosheath, and interplanetary space are modulated by the Jovian longitude relative to the subsolar point; this confirms the Pioneer 10 and 11 results.

• Research Organization: Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771
• OSTI ID: 5567071
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 86:A10; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
BARYONS
CHARGED PARTICLES
EARTH ATMOSPHERE
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
JUPITER PLANET
LEPTONS
MAGNETOSPHERE
MAGNETOTAIL
NUCLEONS
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
PLASMA SHEET
PROTONS