Search Publications
Composition of quasi-stationary solar wind flows from Ulysses/Solar Wind Ion Composition Spectrometer
Geiss, J.; Wimmer-Schweingruber, R. F.; Schwadron, N. A. +6 more
Using improved, self-consistent analysis techniques, we determine the average solar wind charge state and elemental composition of nearly 40 ion species of He, C, N, O, Ne, Mg, Si, S, and Fe observed with the Solar Wind Ion Composition Spectrometer on Ulysses. We compare results obtained during selected time periods, including both slow solar wind…
Properties of coronal mass ejections: SOHO LASCO observations from January 1996 to June 1998
St. Cyr, O. C.; Plunkett, S. P.; Michels, D. J. +9 more
We report the properties of all the 841 coronal mass ejections (CMEs) observed by the Solar and Heliospheric Observatory (SOHO) Large Angle Spectroscopic Coronagraph (LASCO) C2 and C3 white-light coronagraphs from January 1996 through June 1998, and we compare those properties to previous observations by other similar instruments. Both the CME rat…
Solar wind observations over Ulysses' first full polar orbit
Balogh, A.; McComas, D. J.; Goldstein, B. E. +7 more
This study examines solar wind plasma and magnetic field observations from Ulysses' first full polar orbit in order to characterize the high-latitude solar wind under conditions of decreasing and low solar activity. By comparing observations taken over nearly all heliolatitudes and two different intervals covering the same radial distances, we are…
Relationship of halo coronal mass ejections, magnetic clouds, and magnetic storms
Thompson, B. J.; Webb, D. F.; Crooker, N. U. +2 more
Halo coronal mass ejections (CMEs) had been rarely reported in coronagraph observations of the Sun before the Solar and Heliospheric Observatory (SOHO) mission. Since mid-1996, however, the SOHO Large Angle Spectrometric Coronagraph (LASCO) instruments have observed many halo or partial-halo CMEs. A halo CME, especially when associated with solar …
Rigidity dependence of cosmic ray proton latitudinal gradients measured by the Ulysses spacecraft: Implications for the diffusion tensor
Potgieter, M. S.; Heber, B.; Burger, R. A.
The latitudinal gradient of cosmic ray protons observed by Ulysses during September 1994 to July 1995 is small, and it increases as function of rigidity up to ~2 GV and then decreases. Although previous drift models could reproduce the observed small positive gradient for an A>0 solar polarity cycle, they produced a maximum at a rigidity well b…
The origin and development of the May 1997 magnetic cloud
Plunkett, S. P.; Webb, D. F.; Burlaga, L. F. +5 more
A complete halo coronal mass ejection (CME) was observed by the SOHO Large-Angle and Spectrometric Coronagraph (LASCO) coronagraphs on May 12, 1997. It was associated with activity near Sun center, implying that it was aimed earthward. Three days later on May 15 an interplanetary shock and magnetic cloud/flux rope transient was detected at the Win…
Aspects of the mass distribution of interstellar dust grains in the solar system from in situ measurements
Krüger, H.; Grün, E.; Landgraf, M. +2 more
The in situ detection of interstellar dust grains in the solar system by the dust instruments on-board the Ulysses and Galileo spacecraft as well as the recent measurements of hyperbolic radar meteors give information on the properties of the interstellar solid particle population in the solar vicinity. Especially the distribution of grain masses …
A global MHD solar wind model with WKB Alfvén waves: Comparison with Ulysses data
Goldstein, Melvyn L.; Usmanov, Arcadi V.; Besser, Bruno P. +1 more
We use a steady state global axisymmetric MHD model to reproduce quantitatively the Ulysses observations during its first fast latitude traversal in 1994-1995. In particular, we are able to account for the transformation of a surface dipole magnetic field near the Sun into the configuration observed at large heliocentric distances. The MHD equatio…
Variations of Saturn's radio rotation period measured at kilometer wavelengths
Lecacheux, Alain; Galopeau, Patrick H. M.
The Unified Radio and Plasma Wave (URAP) experiment on the interplanetary spacecraft Ulysses is able to detect the Saturnian kilometric radiation (SKR) thanks to the high sensitivity of the receiver and in spite of the remoteness of the planet (8-13 AU). Our knowledge about Saturn comes essentially from the observations by the two Voyager spacecra…
Detection of coronal mass ejection associated shock waves in the outer corona
Sheeley, N. R.; Hakala, W. N.; Wang, Y. -M.
White light coronal images from the Large-Angle Spectrometric Coronagraph (LASCO) on the Solar and Heliospheric Observatory (SOHO) spacecraft show disturbances propagating away from high-speed coronal mass ejections (CMEs). The disturbances are faintly visible ahead of the ejected material at the noses of the CMEs but are strongly visible along th…