Photochemistry-emission coupled model for Europa and Ganymede - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Journal of Space Weather and Space Climate Year : 2016

Photochemistry-emission coupled model for Europa and Ganymede


In the frame of the JUICE mission, preliminary studies of the Jupiter's icy moons, such as Ganymede and Europa, are mandatory. The present paper aims at characterizing the impact of the solar UV flux and its variability on their atmospheres. The solar UV radiation is responsible for the photoionization, photodissociation, and photoexcitation processes within planetary atmospheres. A 1-D photoabsorption model has been developed for different observational geometries, on the basis of a neutral atmospheric model. Considering various production and loss mechanisms but also the transport of oxygen atoms, we estimate the red and green line emissions from photo impact-induced excitation only. These dayglow emissions can represent few percent of the global airglow emission, mainly dominated by electron-induced excitation in auroral regions. For limb viewing conditions, red line emission is bright enough to be detected from actual spectrometers, from 338 R to 408 R according to the solar activity. This is also the case for the green line with 8 R at limb viewing. Considering a different neutral atmosphere model, with an O 2 column density 50% more important, leads to a 14% increase in the red line emissions for limb viewing close to the surface. This difference could be important enough to infer which neutral model is the most likely. However, uncertainties on the solar UV flux might also prevent to constrain the O 2 column density when using ground-based observations in the visible only. The impact of solar flares on the red line emissions for Europa has also been investigated within a planetary space weather context.
Fichier principal
Vignette du fichier
swsc150041.pdf (780.22 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive

Dates and versions

insu-02938731 , version 1 (15-09-2020)





Gaël Cessateur, Mathieu Barthelemy, Isabel Peinke. Photochemistry-emission coupled model for Europa and Ganymede. Journal of Space Weather and Space Climate, 2016, 6, pp.A17. ⟨10.1051/swsc/2016009⟩. ⟨insu-02938731⟩
14 View
32 Download



Gmail Facebook Twitter LinkedIn More