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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…
Radial evolution of outward and inward Alfvénic fluctuations in the solar wind: A comparison between equatorial and polar observations by Ulysses
Bavassano, B.; Pietropaolo, E.; Bruno, R.
Ulysses measurements done during the ecliptic phase of the mission are used to investigate the radial evolution of outward and inward Alfvénic fluctuations at hourly scale in near-equatorial solar wind. This analysis has been stimulated by a recent study on Alfvénic turbulence in polar wind, showing that at hourly scale different radial regimes de…
Field line diffusion in solar wind magnetic turbulence and energetic particle propagation across heliographic latitudes
Veltri, P.; Zimbardo, G.; Pommois, P.
The transport of energetic particles in the heliosphere is strongly influenced by the magnetohydrodynamic turbulence found in the solar wind. This turbulence causes a magnetic field line random walk, which can explain the Ulysses observations at high heliographic latitudes of particles accelerated at corotating interaction regions (CIRs). A three-…
Solar wind plasma parameters on Ulysses: Detailed comparison between the URAP and SWOOPS experiments
McComas, D. J.; Issautier, Karine; Gosling, J. T. +2 more
The presence of several instruments measuring plasma parameters aboard Ulysses made possible an extensive comparison between them. In this paper, we focus on solar wind electron parameters measured by the Unified RAdio and Plasma (URAP) wave receiver, using the thermal noise spectroscopy method, and by the Solar Wind Observations Over the Poles of…
Interplanetary magnetic field: Statistical properties and discrete modes
Lanzerotti, L. J.; Maclennan, C. G.; Thomson, D. J.
We report here detailed statistical studies of power spectra of 1 hour average interplanetary magnetic field (IMF) data that were acquired by the magnetometer instrument on the Ulysses spacecraft in the ecliptic plane of the heliosphere during Ulysses' cruise phase from Earth to Jupiter (October 1990 through January 1992). We have pursued these st…
The transport of interstellar pickup ions
Zank, G. P.; Lu, J. Y.
A new approach to the time-dependent anisotropic propagation of interstellar pickup ions in the interplanetary medium is presented. The model includes the effects of adiabatic focusing in a radial magnetic field, adiabatic deceleration, anisotropic pitch angle scattering, convection in the solar wind, and the continual injection of newly ionized p…
Nature of the boundary between open and closed magnetic field line regions at the Sun revealed by composition data and numerical models
Riley, Pete; Gloeckler, George; Posner, Arik +5 more
Recently, Fisk et al. [1999] have presented a theory that describes a number of features of the large-scale coronal and heliospheric magnetic field. This theory predicts large-scale transport of magnetic flux across the boundaries of the polar coronal holes, which leads to reconnection processes of open field lines with preliminary closed magnetic…
Latitudinal velocity structures up to the solar poles estimated from interplanetary scintillation tomography analysis
Tokumaru, M.; Kojima, M.; Fujiki, K. +3 more
The Ulysses spacecraft observed high-speed wind at high latitudes up to 80° and found that the high-speed solar wind increased in velocity gradually with latitude and that the velocity had asymmetry between Northern and Southern Hemispheres. We have investigated the velocity increase up to the polar regions for the Carrington rotations of 1908-191…
Earthward directed CMEs seen in large-scale coronal magnetic field changes, SOHO LASCO coronagraph and solar wind
Plunkett, S. P.; Mulligan, T.; Hoeksema, J. Todd +4 more
One picture of coronal mass ejection (CME) initiation relates these events to the expansion into space of previously closed coronal magnetic fields, often part of the helmet streamer belt. The work described here makes use of the potential field source surface model based on updated synoptic photospheric field maps to study the large-scale coronal…
Further indications of a ~140 day recurrence in energetic particle fluxes at 1 and 5 AU from the Sun
Balogh, A.; Dalla, S.; Heber, B. +1 more
A possible ~140 day recurrence in the fluxes and anisotropies of interplanetary MeV energy protons has previously been identified in data from the Anisotropy Telescopes (ATs) on board Ulysses. This measurement was made during 1998-1999 at a distance from the Sun of ~5 AU. Earlier reports of a 154-day periodicity in the occurrence rate of solar fla…