No full text
Unpublished conference/Abstract (Scientific congresses and symposiums)
The Spatial Morphology of Equatorial Electron Beams Near Io
Jacobsen, S.; Saur, J. S.; Neubauer, F. M. et al.
2009American Geophysical Union Fall Meeting 2009
 

Files


Full Text
No document available.

Send to



Details



Keywords :
[2704] MAGNETOSPHERIC PHYSICS / Auroral phenomena; [2721] MAGNETOSPHERIC PHYSICS / Field-aligned currents and current systems; [2736] MAGNETOSPHERIC PHYSICS / Magnetosphere/ionosphere interactions; [5737] PLANETARY SCIENCES: FLUID PLANETS / Magnetospheres
Abstract :
[en] The Galileo spacecraft observed energetic field-aligned electron beams very close to Io during several flybys. We apply a three-dimensional magnetohydrodynamic (MHD) model of the far-field Io-Jupiter interaction to simulate for the first time the location and spatial shape of field-aligned electron beams. Io continuously generates MHD waves by disturbing the Jovian magnetoplasma. Currents carried by Alfvén waves propagate predominantly along the magnetic field lines. As the number of charge carriers decreases along the travelpath, electrons are accelerated towards Jupiter. These energetic electrons precipitate into the Jovian ionosphere, visible as prominent Io footprint (IFP) emission. Electrons are also accelerated towards Io and form the equatorial beams observed by the Galileo spacecraft. Unlike the beam formation, the position and spatial structure of these beams has not been addressed in detail before. We use a 3D MHD model with initial conditions corresponding to the individual Galileo flyby and determine the spatial morphology of the beams in Io's orbital plane. Our results are in good agreement with the Galileo observations. We find that the ratio of the one-way traveltime of the Alfvén wave from Io to Jupiter and the convection time of the plasma past the obstacle controls the location of the beams. This leads to the conclusion that at other satellites with other plasma environments, e.g. Ganymede, Callisto, Europa and Enceladus, the electron beams might not be close to the satellite, but can be shifted significantly downstream along its plasma wake. Thus, the future search for field-aligned electron populations near a satellite should be further extended to the wake region.
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Jacobsen, S.
Saur, J. S.
Neubauer, F. M.
Bonfond, Bertrand  ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Gérard, Jean-Claude  ;  Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Grodent, Denis  
Language :
English
Title :
The Spatial Morphology of Equatorial Electron Beams Near Io
Publication date :
14 December 2009
Event name :
American Geophysical Union Fall Meeting 2009
Event place :
San Francisco, United States - California
Event date :
14-18 December, 2009
Audience :
International
Available on ORBi :
since 24 June 2011

Statistics


Number of views
42 (2 by ULiège)
Number of downloads
0 (0 by ULiège)

Bibliography


Similar publications



Contact ORBi