Energetic ion observations in the middle Jovian magnetosphere

Cohen, C. M. S.; Stone, E. C.; Selesnick, R. S.

doi:10.1029/2001ja000008

Cited by 27 publications

(35 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The relative importance of the different sources is also dependent on the energy range considered. For example, the highest‐energy O ions possibly come from the solar wind, while the medium and lower‐energy O ions mostly come from Io [ Cohen et al , 2001]. For energetic particles the most reliable tracer out of this menu is sulfur (S) from Io; however, the spatial distribution of the different mass species can provide clues.…”

Section: Introductionmentioning

confidence: 99%

Energetic ion characteristics and neutral gas interactions in Jupiter's magnetosphere

et al. 2004

View full text Add to dashboard Cite

[1] Spectra, integral moments, and composition (H, He, O, S) of energetic ions (50 keV to 50 MeV) are presented for selected Jupiter magnetospheric positions near the equator between radial distances of $6 to $46 Jupiter radii (R J ), as revealed by analysis of the Galileo Energetic Particle Detector data. These characteristics are then used as the basis of interpreting and modeling reported signatures of energetic ion/neutral gas interactions within Jupiter's inner magnetosphere, particularly energetic neutral atom emissions measured during the Cassini spacecraft flyby of Jupiter. Key findings include the following: (1) sulfur ions significantly dominate the energetic (!50 keV) ion density and pressure at all radial distances >7 R J ; (2) protons dominate integral number and energy intensity planetward of 20-25 R J ; (3) a distinct signature of local, equatorial acceleration of energetic protons is revealed between Io (5.9 R J ) and Europa (9.4 R J ); (4) significant spectral and compositional signatures of neutral gas interactions are also revealed between the orbits of Io and Europa; (5) a previously reported significant depletion of ring current ion populations between Io and Europa during the early-phase operation of Galileo ($1995), as compared with observations obtained during the Voyager epoch (1979), has persisted and probably deepened during later Galileo phases (1999); and (6) detailed energetic neutral atom emission modeling, based on the in situ results reported here, further constrains recent estimates of the contents of the neutral gas torus of Europa.

show abstract

Section: Introductionmentioning

confidence: 99%

Energetic ion characteristics and neutral gas interactions in Jupiter's magnetosphere

et al. 2004

View full text Add to dashboard Cite

show abstract

“…[3] The theory predicts that the radiation belt energetic ions originating from Io should be singly ionized, in contrast to the ions of solar origin observed in Jupiter's middle magnetosphere that are expected to be in high charge states [Cohen et al, 2001]. Lower-energy ions have been observed in several charge states (+1 to +4 for both O and S), in the Io torus itself for energy-per-charge up to 6 kV [Bagenal, 1994] and in the middle magnetosphere for up to 60 kV [Geiss et al, 1992], but these are not thought to be the source of the radiation belt ions.…”

Section: Introductionmentioning

confidence: 99%

Charge states of energetic ions in Jupiter's radiation belt inferred from absorption microsignatures of Io

Selesnick

Cohen

2009

J. Geophys. Res.

Self Cite

View full text Add to dashboard Cite

[1] The Heavy Ion Counter on the Galileo Jupiter orbiter observed depletions of energetic (^5 MeV/nucleon) oxygen and sulfur ions near Io that are interpreted as absorption microsignatures. The two elements were equally abundant in this region of Jupiter's radiation belt. Numerical simulations of microsignatures from Galileo orbits 27, 31, and 32, based on calculations of ion trajectories in models of the magnetospheric and Alfvén wing magnetic fields, show that the data are most consistent with the ions being fully ionized or nearly so. The conclusion is independent of field model inaccuracies, which cause some discrepancy between simulations and data, because the Alfvén wing field significantly deflects only those trajectories with relatively small gyroradii.

show abstract

“…Reconnection that operates in the nightside magnetosphere is most likely to contribute to the energization. In addition to this, Galileo has found evidence that ions are accelerated to MeV nucleon À1 energies in the middle magnetosphere near 25 R J (Cohen et al, 2001). The composition of these particles shows that solar material dominates.…”

Section: Jupiters Rotating Magnetospherementioning

confidence: 90%

Driving mechanisms of magnetospheric dynamics of planets and satellites

Nishida

2004

Advances in Space Research

View full text Add to dashboard Cite

Energetic ion observations in the middle Jovian magnetosphere

Cited by 27 publications

References 22 publications

Energetic ion characteristics and neutral gas interactions in Jupiter's magnetosphere

Energetic ion characteristics and neutral gas interactions in Jupiter's magnetosphere

Charge states of energetic ions in Jupiter's radiation belt inferred from absorption microsignatures of Io

Driving mechanisms of magnetospheric dynamics of planets and satellites

Contact Info

Product

Resources

About