DPS 2001 meeting, November 2001
Session 17. Io, Tori, and Satellite Atmospheres Posters
Displayed, 9:00am Tuesday - 3:00pm Saturday, Highlighted, Wednesday, November 28, 2001, 10:30am-12:30pm, French Market Exhibit Hall

[Previous] | [Session 17] | [Next]

[17.07] Optical Emissions from the Atmosphere of Io due to Flux Tube Electron Interaction

M. Michael, A. Bhardwaj (Space Physics Laboratory, Vikram Sarabhai Space Centre, India)

Visible emissions from the atmosphere of Io have been observed recently by Imaging science experiments on board Galileo and Cassini. The features observed of Galileo, in the wavelength range 380 to 1040 nm, include a bright blue emission close to the equator, a weaker red emission along the limb, and a faint green emission concentrated on the nightside. Cassini made observations in the wavelength range 265 to 830 nm with a maximum intensity of 100 kR in the wavelength range 300 to 380 nm. The equatorial glows observed by both Galileo and Cassini seem to shift in latitude according to the jovian magnetic field lines: providing clear evidence that the equatorial visible aurora originate in electrical currents that connect Io and Jupiter along the jovian magnetic field lines. Galileo particle experiments have recently observed bi-directional magnetically field-aligned electrons near Io of energies 15-150 keV by Energetic Particle Detector (EPD) and 0.1-5 keV by Plasma Science (PLS) instruments. A Monte Carlo model is constructed to study the interaction of these Jovian magnetic field-aligned electrons with the neutral species present in the atmosphere of Io. It is found that the electrons observed by EPD are incapable of producing the observed emissions. The PLS-observed electrons can explain the Galileo-SSI observed emission brightness if these electrons precipitate into a thick atmosphere of Io.

The author(s) of this abstract have provided an email address for comments about the abstract: marykuttymichael@yahoo.com

[Previous] | [Session 17] | [Next]