Search Publications
Comparison of ≳40 keV Electron Events at High and Low Heliolatitudes: Ulysses/HI-SCALE and ACE/EPAM
Lario, D.; Roelof, E. C.; Ho, G. C. +2 more
We have performed a joint survey of anisotropic ≳40 keV electron events from August 1997 to September 2000 using the matched detectors on the Ulysses (ULS)/HI-SCALE and the ACE/EPAM instruments. A computer algorithm selected events with strong, statistically significant pitch-angle anisotropies. Electron pitch-angle distributions at ACE (∼1 AU) ar…
Survey of MeV proton anisotropies measured by Ulysses
Balogh, André; Dalla, Silvia
The Anisotropy Telescopes (ATs) instrument, part of the COSPIN experiment on board Ulysses, measures fluxes and anisotropies of protons in the MeV range. We survey data from this instrument throughout the Ulysses mission, with particular emphasis on solar maximum, when large particle intensities were measured. The only significant fluxes detected …
Coronal Heating and Solar Wind Acceleration: Future Work on Observations
Peter, Hardi
The space-based observatories SOHO and TRACE have shown some very interesting results on the structure and dynamics of the Sun and its atmosphere, e.g., the extremely high ion temperatures or the enormous variability in the corona. But one question is still open to debate: how to use these data to distinguish between different types of physical he…
Observations of the Acceleration of Polar Solar Wind Near Solar Maximum
Simnett, G. M.; Tappin, S. J.; Lyons, M. A.
In a previous paper (Tappin et al., 1999) we used cross-correlation analysis of high-cadence observations with the LASCO coronagraphs to trace the acceleration of the solar wind at low latitudes. In this paper we present a similar analysis carried out over the North pole of the Sun. The observations which were made in March 2000 with the C3 corona…
Solar Origin of Anisotropic Electron Events observed by ULYSSES and ACE
Pick, M.; Hawkins, S. E., III; Maia, D.
We investigate the solar origin of energetic collimated electron events observed in situ by the EPAM and/or HISCALE particle experiments aboard the ACE and ULYSSES spacecraft, respectively. This study has been performed for two months, September and October 1999 when Ulysses was magnetically connected to the solar disk at heliolongitudes visible a…
The Evolution of the Anomalous Cosmic Ray Oxygen Spectra From 1995 to 1998: Ulysses Observations
Fränz, M.; Keppler, E.; Heber, B. +3 more
Moraal and Steenberg (1999), showed that the peak energy in the anomalous cosmic ray spectra is independent of the radial distance up to a few AU away from the termination shock but dependent on the solar wind speed, the radius of the termination shock and the scattering strength. In this paper we will discuss the variation of the cosmic ray oxyge…
The Onset of Long Term Modulation in the Heliosphere in Cycle 23
Kunow, H.; Wibberenz, G.; Heber, B. +8 more
The combination of Voyager 1 (77.9 AU, 34.4° N) and Voyager 2 (61.2 AU, 24.5° S) at moderate heliolatitudes in the distant heliosphere and Ulysses with its unique latitudinal surveys in the inner heliosphere along with IMP 8 and other satellites at 1 AU constitutes a network of observatories that are ideally suited to study cosmic rays over the so…
Fine Structure in the Corona at High Latitudes at Solar Maximum
Suess, S.
Microstreams and pressure balance structures in fast solar wind were more easily detected at Ulysses at 2.2 AU over the poles than at Helios at 0.3 AU. This is because solar rotation leads to dynamic interactions between different speed regimes at a rate that depends on latitude for the same size features. Dynamic interactions make structures more…
Energetic Ions Observed at Low to High Latitudes in the Southern Heliosphere During Declining and Rising Solar Activity
Forsyth, R. J.; Goldstein, B. E.; Sanderson, T. R. +3 more
We present and compare observations of energetic protons during the two first transits of the Ulysses spacecraft from low to high latitudes in the southern heliosphere. Protons in the energy range 1.8 3.8 MeV from the COSPIN experiment are studied for global trends and in relation to some ambient structures in the solar wind (corotating interactio…