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Recent Observations of the Heliospheric Magnetic Field at Ulysses: Return to Low Latitude
Balogh, A.; Tsurutani, B. T.; Smith, E. J. +2 more
Ulysses recently completed a second slow latitude scan of the northern heliosphere, a descent from 80.2°N in July 1995 to the solar equator in December 1997. These recent magnetic field observations complement those from the south hemisphere and reveal new features as well as the effect of the changing solar cycle. Five topics are emphasized in th…
Galactic Cosmic Ray Observations at Different Heliospheric Latitudes
Heber, Bernd; Potgieter, Marius S.
The local interstellar spectra (LIS) of galactic cosmic rays at low energies cannot be determined from measurements made near Earth, because of strong solar modulation processes from the heliospheric boundary to the observer. Computations done in the seventies based on Parker's cosmic ray modulation theory taking into account diffusion, convection…
Energetic Particle Signatures of a Corotating Interaction Region from a High Latitude Coronal Hole: SOHO, Wind and Ulysses Observations
Thompson, B. J.; Lazarus, A. J.; Kunow, H. +10 more
In mid 1996 the Comprehensive Suprathermal and Energetic Particle Analyser (COSTEP) onboard the Solar and Heliospheric Observatory, at 1 AU in the ecliptic plane, detected recurrent periods of enhanced MeV ions in association with a corotating interaction region (CIR). Measurements of energetic ions from the Cosmic Ray and Solar Particle Instrumen…
The Sun and the Solar Wind Close to the Sun
Suess, S. T.
One of the benefits of the Ulysses, SOHO, and YOHKOH missions has been a strong stimulus to better understand the magnetohydrodynamic processes involved in coronal expansion. Three topics for which this has been especially true are described here. These are: (i) The observed constancy of the radial interplanetary magnetic field strength (as mapped…
On the Sources of Jovian Hectometric Radiation
Misawa, H.; Morioka, A.; Nakagawa, F.
Jovian hectometric radiation(HOM) emitted from the polar region of the Jovian magnetsphere reflects the information on the electro-magnetic environment of the source region. Using the Ulysses URAP and SWOOPS data, the occurrence characteristics of HOM and its relation to the solar wind were investigated. As a result, we found that HOM can be class…
Study of CME Structure and Evolution Deduced from Ulysses/Hi-Scale Energetic Particle Observations
Malandraki, O.; Sidiropoulos, N.; Saris, E. T. +1 more
In this work, we study the anisotropy characteristics of solar energetic electron (E > 53 keV) fluxes observed by the ULYSSES/HI-SCALE instrument during the passage of a well-identified Coronal Mass Ejection. On the basis of the energetic electron observations, firm conclusions are drawn on whether the detected Coronal Mass Ejection has been de…
Cooling of Energetic Particles during their Transport along Spiral Field Lines
Kóta, J.
The transport of low-energy charged particles moving along magnetic field lines is considered. We point out that particles accelerated at CIRs at larger heliocentric distances and moving inward along the spiral field lose energy and decelerate even in a purely scatter free case. This results in a sizeable reduction in intensity. Scattering increas…
Radial Distance Dependence of the Solar Wind Speed at High Latitudes Observed by Interplanetary Scintillation
Tokumaru, M.; Kojima, M.; Yokobe, A.
We have investigated the radial distance dependence of the solar wind speed during the years 1995 and 1996 using interplanetary scintillation (IPS) observations at the Solar-Terrestrial Environment Laboratory. We derived solar wind velocity distributions for regions inside and outside of 0.3 AU separately using a computerized tomography method to …