Space and Planetary Science; Geophysics; Jupiter; Juno; aurora; Io footprint; JIRAM
Abstract :
[en] One of the auroral features of Jupiter is the emission associated with the orbital motion of its moon Io. The relative velocity between Io and the surrounding plasma trigger perturbations that travels as Alfvén waves along the magnetic field lines toward the Jovian ionosphere. These waves can accelerate electrons into the atmosphere and ultimately produce an auroral emission, called the Io footprint. The speed of the Alfvén waves—and hence the position of the footprint—depends on the magnetic field and on the plasma distribution along the field line passing through Io, whose SO2‐rich atmosphere is the source of a dense plasma torus around Jupiter. Since 2016, the Jovian InfraRed Auroral Mapper (JIRAM) onboard Juno has been observing the Io footprint with a spatial resolution of ∼few tens of km/pixel. JIRAM detected evidences of variability in the Io footprint position that are not dependent on the System III longitude of Io. The position of the Io footprint in the JIRAM images is compared with the position predicted by a model of the Io Plasma Torus and of the magnetic field. This is the first attempt to retrieve quantitative information on the variability of the torus by looking at the Io footprint. The results are consistent with previous observations of the density and temperature of the Io Plasma Torus. However, we found that the plasma density and temperature exhibit considerable non‐System III variability that can be due either to local time asymmetry of the torus or to its temporal variability.
Research Center/Unit :
STAR - Space sciences, Technologies and Astrophysics Research - ULiège
Disciplines :
Space science, astronomy & astrophysics
Author, co-author :
Moirano, A. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy ; Sapienza University of Rome Rome Italy
Mura, A. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Bonfond, Bertrand ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Connerney, J. E. P. ; Space Research Corporation Annapolis MD USA
Dols, V. ; Laboratory for Atmospheric and Space Physics University of Colorado Boulder Boulder CO USA
Grodent, Denis ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Hue, V. ; Southwest Research Institute San Antonio TX USA
Gérard, Jean-Claude ; Université de Liège - ULiège > Département d'astrophysique, géophysique et océanographie (AGO) > Labo de physique atmosphérique et planétaire (LPAP)
Tosi, F. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Migliorini, A. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Adriani, A. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Altieri, F. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Castagnoli, C. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy ; Institute of Atmospheric Sciences and Climate National Research Council (CNR ‐ ISAC) Bologna Italy ; University of Rome Tor Vergata Rome Italy
Cicchetti, A. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Dinelli, B. M. ; Institute of Atmospheric Sciences and Climate National Research Council (CNR ‐ ISAC) Bologna Italy
Grassi, D. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Moriconi, M. L. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Noschese, R. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Piccioni, G.; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Plainaki, C. ; Italian Space Agency (ASI) Rome Italy
Scarica, P. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Sindoni, G.; Italian Space Agency (ASI) Rome Italy
Sordini, R. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Turrini, D.; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
Zambon, F. ; Institute for Space Astrophysics and Planetology National Institute for Astrophysics (INAF—IAPS) Rome Italy
ASI - Agenzia Spaziale Italiana Jet Propulsion Laboratory BELSPO - Belgian Federal Science Policy Office NASA - National Aeronautics and Space Administration F.R.S.-FNRS - Fonds de la Recherche Scientifique
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