Search Publications
Trapped energetic ions in Jupiter's inner magnetosphere
Anglin, J. D.; Burrows, J. R.; Mu, J. L. +1 more
Ion measurements made with the high-flux telescope at ~1MeV/nucleon during the passage of the Ulysses spacecraft through Jupiter's inner magnetosphere are presented. Stable pancake-shaped pitch angle distributions were observed for protons inside ~17RJ. They are fitted by a time-independent model in which an assumed directional flux at …
Alfvénic fluctuations in fast and slow solar winds
Orlando, S.; Peres, G.; Rosner, R. +1 more
We compute properties of Alfvénic fluctuations within a wide frequency range (i.e., 10-6s-1<~f<~10-2s-1) in both high- and low-speed magnetized radial solar winds. In particular, the radial and frequency variations of the normalized cross helicity σc, the Alfvén ratio <script>R<…
Comparison of IUE and HST diagnostics of the Jovian Aurorae
Livengood, T.; Harris, W. M.; Prangé, R. +2 more
Analysis of international ultraviolet explorer (IUE) and Voyager ultraviolet spectrometer (UVS) spectra of the Jovian auroral emission indicates that the Jovian auroral brightness is modulated in longitude (brighter near 180° in the north and 20° in the south) and that there is a color ratio asymmetry associated with this brightening. The purpose …
Three-dimensional nature of interaction regions: Pioneer, Voyager, and Ulysses solar cycle variations from 1 to 5 AU
Smith, Edward J.; González-Esparza, J. Américo
We combined in-ecliptic observations of interaction regions from 1 to 5 AU by four spacecraft that traveled to Jupiter at different phases of the solar cycle: Pioneer 11 (declining phase of cycle 20), Voyager 1 and 2 (ascending phase of cycle 21), and Ulysses (just after solar maximum 22). We used this set of 97 interaction regions to study two di…
Spatial variations of 0.2 to 5 MeV protons in the 1-5 AU in-ecliptic region from Ulysses, Voyager 1 and 2, and IMP 8 gradient studies
Armstrong, Thomas P.; Boufaida, Moncef
Protons with energies ranging from 0.3 to 2 MeV are nearly always present in the environment of Earth. Solar flare events and interplanetary shock waves can be identified as producing or enhancing these fluxes. However, interplanetary particles are observed even in the absence of solar flares. Explaining the presence of these proton fluxes in the …
Three-dimensional nature of interaction regions: Pioneer, Voyager, and Ulysses solar cycle variations from 1 to 5 AU
Smith, Edward J.; Américo González-Esparza, J.
Solar origin of the 26-day periodicity observed by Ulysses
Weber, M.; Hoeksema, J. T.; Acton, L. W. +1 more
The Ulysses spacecraft discovered that the interplanetary magnetic sector structure went through a major restructuring in mid-1992. The observed recurrence period changed from about 25.4 days to about 26.2 days. Another interesting discovery is that the solar wind speed, energetic particle fluxes, and interplanetary magnetic field all varied quasi…
Plasma wave characteristics of the jovian magnetopause boundary layer: Can wave-particle interactions cause the jovian aurora?
Krupp, N.; Balogh, A.; Tsurutani, B. T. +10 more
Interstellar pickup ions and quasi-perpendicular shocks: Implications for the termination shock and interplanetary shocks
Zank, G. P.; Webb, G. M.; Pauls, H. L. +1 more
A new mechanism for the acceleration of pickup ions by repeated reflections from the electrostatic cross shock potential of a quasi-perpendicular shock is presented. The acceleration mechanism, multiply reflected ion (MRI) acceleration, offers a resolution to the issue of injecting pickup ions into an efficient particle energization scheme, and th…
Motion of the footpoints of heliospheric magnetic field lines at the Sun: Implications for recurrent energetic particle events at high heliographic latitudes
Fisk, L. A.
The interplay between the differential rotation of the footpoints of heliospheric magnetic field lines in the photosphere and the subsequent nonradial expansion of these same field lines with the solar wind from rigidly rotating coronal holes can result in extensive excursions of heliospheric magnetic field lines with heliographic latitude. Thus m…