Effects of Io's volcanos on the plasma torus and Jupiter's magnetosphere
Io's volcanism can have dominant effects on Jupiter's magnetosphere. A model is developed in which a neutral gas torus is formed at Io's orbit by volcanic SO/sub 2/ escaping from Io. Ionization and dissociation of volcanic SO/sub 2/ is shown to be the dominant source of plasma in Jupiter's magnetosphere. The failure of Voyager observations to confirm predictions of the magnetic anomaly model is naturally explained. A 30--50 KeV sulfur and oxygen ion plasma is formed in the outer magnetosphere, with density roughly equal to the proton density there, by ionization of sulfur and oxygen atoms on highly eccentric elliptical orbits around Jupiter. When these atoms are ionized in the outer magnetosphere, they are swept up by the Jovian magnetic field and achieve 30--50 keV energies. Such atoms are created by dissociative attachment of SO/sub 2/ by < or approx. =10 eV electrons. Substantial losses of radiation-belt charged particles result from passage through the neutral gas torus. Such losses can account for observed anomalies in charged particle depletions near Io; these could not be understood in terms of satellite sweeping alone. Substantial ionization energy loss occurs for < or approx. =1 MeV protons and < or approx. =100 keV electrons; losses of < or approx. =1 MeV protons are much greater than for comparable energy electrons. Losses of < or approx. =1 MeV per nucleon ions are also severe. Other consequences of the model include intrinsic time variability in the Jovian magnetosphere, on times > or approx. =10/sup 6/ s, caused by variations in Io's volcanic activity. Charged particle losses in the neutral gas torus tend to yield dumbbell-shaped pitch-angle distributions. Negative ions are predicted in the Io plasma torus.
- Research Organization:
- Department of Physics and Astronomy, Rutgers University
- OSTI ID:
- 6617068
- Journal Information:
- Astrophys. J.; (United States), Vol. 242:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
JUPITER PLANET
PLANETARY MAGNETOSPHERES
CHARGE EXCHANGE
CHARGED PARTICLES
ELECTRONS
ION-ATOM COLLISIONS
IONIZATION
IONS
MAGNETIC FIELDS
PLASMA
PROTONS
RADIATION FLUX
SULFUR DIOXIDE
VOLCANOES
ATMOSPHERES
ATOM COLLISIONS
BARYONS
CHALCOGENIDES
COLLISIONS
ELEMENTARY PARTICLES
FERMIONS
HADRONS
ION COLLISIONS
LEPTONS
NUCLEONS
OXIDES
OXYGEN COMPOUNDS
PLANETARY ATMOSPHERES
PLANETS
SULFUR COMPOUNDS
SULFUR OXIDES
640107* - Astrophysics & Cosmology- Planetary Phenomena