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The heliospheric current sheet
Smith, Edward J.
The heliospheric current sheet (HCS) is the boundary between open oppositely directed magnetic field lines which commonly originate as the outward extension of the solar magnetic dipole. The dipole tilt, the rotation of the Sun, and the outward propagation of the solar wind cause peaks and valleys in the current sheet which spiral outward. The HCS…
Modulation of Jovian and galactic electrons in the heliosphere: 1. Latitudinal transport of a few MeV electrons
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +2 more
The heliospheric modulation of galactic and Jovian electrons is studied using a fully three-dimensional, steady state model based on Parker's transport equation including the Jovian source. The modulation of low-energy electrons is a handy tool to establish and to construct a suitable diffusion tensor to assure compatibility between model computat…
Helium energetics in the high-latitude solar wind: Ulysses observations
Reisenfeld, D. B.; McComas, D. J.; Steinberg, J. T. +4 more
We present a study of the interplanetary evolution of solar wind helium (alpha particle) energetics. The analysis of Ulysses observations of the fast high-latitude solar wind concentrates on the radial evolution of the alpha-proton differential streaming vαp, the alpha temperature, and the alpha temperature anisotropy. Ulysses observati…
Ionization state and magnetic topology of coronal mass ejections
Woch, J.; Schwenn, R.; Balogh, A. +5 more
Charge state distributions of heavy solar wind ions measured in interplanetary space can be used to probe the physical conditions in the solar corona. This paper presents a study of the charge state distributions and the magnetic topology of 56 coronal mass ejections (CMEs) observed in interplanetary space by the Ulysses spacecraft. The analysis o…
Ion distributions in large magnetic holes in the fast solar wind
Smith, E. J.; Goldstein, B. E.; Neugebauer, M. +3 more
Magnetic holes are isolated localized depressions in the magnitude of the interplanetary magnetic field. Six examples of long-duration (9 to 30 min) magnetic holes observed by the Ulysses spacecraft at high heliographic latitudes near 3 AU are studied in detail. Each of the holes was in pressure balance with its surroundings. The proton-proton and…
Evolution of magnetic field fluctuations in high-speed solar wind streams: Ulysses and Helios observations
Balogh, A.; Horbury, T. S.
Ulysses magnetic field measurements in high-speed streams emanating from the Sun's polar coronal holes reveal a complex combination of fluctuations on different scales. Measurements of the wavenumber dependence of radial and latitudinal power scaling, spectral index, and anisotropy of undisturbed polar magnetic field fluctuations between 1.4 and 4…
Modulation of Jovian and galactic electrons in the heliosphere: 2. Radial transport of a few MeV electrons
Fichtner, H.; Ferreira, S. E. S.; Potgieter, M. S. +3 more
Previously, the latitudinal transport of ~7 MeV electrons was studied by comparing the results of a newly developed three-dimensional model, based on the numerical solution of Parker's transport equation including the Jovian source, with Ulysses observations. Here, the radial transport of ~16 MeV electrons is studied by comparing the model results…
Distribution of magnetic field components in the solar wind plasma
Matthaeus, W. H.; Smith, C. W.; Padhye, N. S.
We examine the probability distribution functions (PDFs) of fluctuations of magnetic field components using the Ulysses and Omnitape data sets to evaluate departures from Gaussian distributions. Functional fits as well as moment comparisons (kurtoses) are used in drawing conclusions concerning the degree of non-Gaussianity. Short-timescale fluctua…
Processes associated with particle transport in corotating interaction regions and near stream interfaces
Horbury, T. S.; Forsyth, R. J.; Kunow, H. +5 more
Pioneer and Ulysses observations of energetic particles and solar wind plasma and magnetic fields are analyzed to study particle transport in corotating interaction regions (CIRs) and near stream interfaces (SIs). Energetic particle diffusion with a lowered coefficient near the SIs as compared with the free solar wind may account for the energetic…
Magnetic cloud evolution in a two-speed solar wind
Cargill, Peter J.; Schmidt, Joachim M.
The Ulysses spacecraft has observed interplanetary coronal mass ejections in pure high-speed solar wind, in the shear layer between high-speed and low-speed, and, in conjunction with other satellites, the same coronal mass ejection (CME) has been seen in both high- and low-speed wind. If CMEs originate in the equatorial streamer belt, they must be…