Studies of Io's atmosphere and plasma torus

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:7059223

Moreno, M A

Jupiter's hot and cold plasma tori and the atmosphere of Io, a jovian moon located in a nearly circular orbit at a distance of 5.9 jovian radii from the center of Jupiter are examined. For the hot torus the ion partitioning and energy balance are modeled by assuming that there are independent sources of neutral sulfur and oxygen atoms, that the thermal electrons have a density of 2000/cu cm and a temperature of 5 eV. In the model of energy and mass balance of the cold torus its primary source of plasma is considered a radial diffusion inward from the hot torus. The time scale for this process is assumed to be identical to that required for energetic electrons to supply the energy necessary to power the synchrotron radiation. Charge exchange between thermal ions and an extended neutral cloud of sulfur and oxygen produces fresh ions which are accelerated to corotation by the magnetic field of Jupiter. These fresh accelerated ions are the source of energy which powers the cold torus emissions. The main ion loss mechanism is a two-step process whereby charge exchange between ions and neutral molecules transforms ions into fast neutrals. Since it is generally agreed that the source of neutrals to the hot and cold tori is the atmosphere of Io, then in order to better understand torus processes the behavior of Io's atmosphere needs to be understood. Numerical gasdynamic SO2 models of sublimation and volcanic atmospheres of Io are developed by means of computer simulations. Using a fine computational grid and the computational capabilities of the Cray supercomputers, the relevant atmospheric properties such as pressure, density, temperature, and velocity are found. Day side and night side atmospheres were investigated. It was found that volcanoes form an extended atmosphere on Io. A sublimation H2S atmosphere was also investigated.

• Research Organization: California Univ., Los Angeles, CA (USA)
• OSTI ID: 7059223
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
CHARGE EXCHANGE
CHARGED PARTICLES
COMPUTERIZED SIMULATION
DATA
DISTRIBUTION
ENERGY BUDGETS
INFORMATION
IONS
JUPITER PLANET
MAGNETIC FIELDS
MASS DISTRIBUTION
MATHEMATICAL MODELS
NUMERICAL DATA
OXYGEN IONS
PLANETARY ATMOSPHERES
PLANETS
PLASMA
SIMULATION
SPATIAL DISTRIBUTION
THEORETICAL DATA
VOLCANOES