The Structure of Io's Thermal Corona and Implications for Atmospheric Escape
Abstract
A steady-state model of Io's exospheric corona and its interaction with the Io plasma torus is used to study the escape of species from Io's atmosphere. It is found that atmospheric sputtering is the major escape mechanism for models in which the plasma flow reaches the critical level, and that such models produce total mass-loading rates an order of magnitude larger than values inferred from observations. The results suggest the presence of an extended Na coronal component in the thermal exosphere, and are consistent with an O-dominated corona, an exospheric temperature of about 1000 K, an Na critical level mixing ratio of 0.001, and a critical level radius of about 1.5 Io radii.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 1989
- DOI:
- 10.1086/167720
- Bibcode:
- 1989ApJ...343..468S
- Keywords:
-
- Atmospheric Composition;
- Io;
- Planetary Magnetospheres;
- Satellite Atmospheres;
- Magnetohydrodynamic Flow;
- Steady State;
- Toroidal Plasmas;
- JUPITER;
- SATELLITES;
- IO;
- THERMAL PROPERTIES;
- STRUCTURE;
- CORONAS;
- ESCAPE;
- ATMOSPHERE;
- PLASMA TORUS;
- KINETICS;
- TEMPERATURE;
- RADIUS;
- MIXING;
- PLASMA;
- EXOSPHERE;
- SPUTTERING;
- MASS LOADING;
- SODIUM;
- MAGNETOSPHERE;
- CALCULATIONS;
- MODELS;
- OXYGEN;
- CHARGE EXCHANGE;
- IONIZATION;
- JETS;
- PARAMETERS;
- Lunar and Planetary Exploration; Satellites of Jupiter;
- PLANETS: MAGNETOSPHERES;
- PLANETS: SATELLITES