Solar control of sodium escape from Io - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Geophysical Research. Planets Année : 2014

Solar control of sodium escape from Io

Résumé

We report ground-based spectroscopic observations of the Io sodium cloud before and after eclipse by Jupiter, in a search for possible effects of sunlight on the total atomic sodium content in Io's exosphere. These observations test the importance of the sun in maintaining the supply of atoms from the thicker atmosphere, which lies close to the surface, to the thinner, more extended, sodium cloud. We performed ground-based spectroscopy of the sodium doublet at 589 nm with a high-resolution échelle spectrograph on the Italian National Telescope Galileo (TNG) on La Palma Island. We find that the total atomic sodium content immediately after eclipse falls by a factor of ~4 during eclipse and recovers to pre-eclipse values on a timescale of ~5 hours. We evaluate potential causes of the precipitous drop including condensation of the atmosphere, collapse of the ionosphere, and changes in atmospheric chemistry. We conclude that most plausible cause of the drop in atomic sodium production is the interruption of photodissociation of sodium-bearing molecules during eclipse. We discuss further implications of this change in atmospheric chemistry.
Fichier principal
Vignette du fichier
2013JE004504.pdf (596.96 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte

Dates et versions

hal-00952745 , version 1 (12-01-2021)

Identifiants

Citer

Cesare Grava, Nicholas M. Schneider, François Leblanc, Jeffrey P. Morgenthaler, Valeria Mangano, et al.. Solar control of sodium escape from Io. Journal of Geophysical Research. Planets, 2014, 119 (3), pp.404-415. ⟨10.1002/2013JE004504⟩. ⟨hal-00952745⟩
129 Consultations
30 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More