Search Publications
Low-frequency electromagnetic plasma waves at comet P/Grigg-Skjellerup analysis and interpretation
Coates, A. J.; Neubauer, Fritz M.; Glassmeier, Karl-Heinz +1 more
The propagation and polarization characteristics of low-frequency electromagnetic wave fields near comet P/Grigg-Skjellerup (P/GS) are analyzed using magnetic field and plasma observations obtained by the Giotto magnetometer experiment and the Johnstone plasma analyzer during the encounter at the comet on July 10, 1992. The results have been physi…
Source characteristics of Jovian narrow-band kilometric radio emissions
Kaiser, M. L.; Desch, M. D.; Zarka, P. +5 more
New observations of Jovian narrow-bank kilometric (nKOM) radio emissions were made by the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in early February 1992. These observations have demonstrated the unique capability of the URAP instrument for determining both the direction and pol…
Source characteristics of Jovian hectometric radio emissions
Stone, R. G.; Fainberg, J.; Reiner, M. J.
Direct confirmation that low-frequency Jovian hectometric (HOM) radio emissions centered near 0° central meridian longitude consist of distinct, oppositely polarized northern and southern beams has been achieved using data from the Unified Radio and Plasma Wave (URAP) experiment on the Ulysses spacecraft during the Ulysses-Jupiter encounter in ear…
Jovian electron propagation in three dimensions of the heliosphere: The Ulysses investigations
Balogh, A.; Smith, D. A.; Simpson, J. A. +1 more
We report investigations of Jovian relativistic electrons in the interplanetary medium that provide new insights into both the physical processes by which the Jovian magnetosphere releases its trapped relativistic electrons into the interplanetary medium, and the modes of their interplanetary propagation. These studies were dependent on the unique…
Time-variable magnetospheric radio emissions from Jupiter
Kaiser, M. L.
Jupiter is the source of a large number of independent nonthermal radio sources, all of which vary with time. The known causes of the variations include planetary rotation modulation, modulation by Io and/or its torus, and influence by the solar wind which can reach surprisingly deep into the Jovian magnetosphere. However, a significant number of …
Ulysses plasma observations in the Jovian magnetosheath
Thomsen, M. F.; Smith, E. J.; Bame, S. J. +2 more
The solar wind plasma experiment aboard the Ulysses spacecraft, including separate ion and electron instruments, measured the plasma properties of the Jovian magnetosheath during the February 1992 encounter with Jupiter. Seven separate magnetosheath intervals were observed, as well as four bow shock crossings and numerous encounters with the magne…
Variability of [O I] 6300-Å emission near Io
Smyth, W. H.; Scherb, F.
Observations of [O I] 6300-Å emission near Io have been obtained in 1990, 1991, and 1992 by the National Solar Observatory staff using the solar-stellar spectrograph on the McMath-Pierce telescope at Kitt Peak. High-resolution spectra with a resolving power of about 1.2×105 were obtained with an integration time of 10-15 min each. The v…
High-velocity tails on the velocity distribution of solar wind ions
Geiss, J.; Gloeckler, G.; Wilken, B. +2 more
Recent observations of the solar wind using the SWICS instrument on the Ulysses spacecraft have shown the presence of high-velocity ``tails'' on the velocity distribution of protons. Similar features have also been observed on the velocity distributions of helium and oxygen ions. Of the order of 1% of the solar wind density is involved in these ta…
Optically thin H Lyman alpha production on outer planets: Low-energy proton acceleration in parallel electric fields and neutral H atom precipitation from ring current
Bhardwaj, A.; Singhal, R. P.
A Monte Carlo model has been constructed to describe the energization and energy degradation of low-energy protons in an H2 atmosphere in the presence of parallel electric field. The energy spectrum of Ly α collision events is employed to determine the volume emission rate (VER) of H Ly α emissions. Numerical experiments have been perfo…
Mass loading and velocity diffusion models for heavy pickup ions at comet Grigg-Skjellerup
Coates, A. J.; Neubauer, Fritz M.; Johnstone, A. D. +1 more
We compare model predictions of cometary water group ion densities and the solar wind slow down with measurements made by the Giotto Johnstone plasma analyzer implanted ion sensor at the encounter with comet Grigg-Skjellerup (G-S) on July 10, 1992. The observed slope of the ion density profile on approach to the comet is unexpectedly steep. Possib…