The atmosphere and ionosphere of Io

Abstract

view Abstract Citations (45) References (22) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The atmosphere and ionosphere of Io. McElroy, M. B. ; Yung, Y. L. Abstract Models for Jupiter's innermost Galilean satellite's atmosphere, ionosphere, and sodium airglow are developed on the basis of recent observational data. The sodium emission detected by Brown (1973) is seen to require a collisional excitation process in Io's atmosphere, while the extended sodium emission measured by Trafton et al. (1974) may require scattering of the planetary radiation by an extended sodium cloud. The sodium is presumably present in bound form on Io's surface, and may be released by a sputtering mechanism proposed by Matson et al. (1974). The ionosphere detected by a radio occultation experiment on Pioneer 10 could be attributed to photoionization of atmospheric sodium, provided Io's atmosphere could sustain significant upward motions during daytime and downward motions during nighttime. The incomplete hydrogen torus observed by Judge and Carlson (1974) in the vicinity of Io appears to require a large supply of hydrogen from the satellite's atmosphere. Implications of the hydrogen torus for the energy and mass balance of Jupiter's magnetosphere are discussed. Publication: The Astrophysical Journal Pub Date: February 1975 DOI: 10.1086/153408 Bibcode: 1975ApJ...196..227M Keywords: Atmospheric Composition; Atmospheric Models; Diurnal Variations; Io; Natural Satellites; D Lines; Electron Density Profiles; Hydrogen; Jupiter Atmosphere; Line Spectra; Lyman Alpha Radiation; Planetary Ionospheres; Plasma Clouds; Sodium; Sputtering; Toruses; Lunar and Planetary Exploration full text sources ADS |