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Stream Interaction Regions at High Heliographic Latitudes During Ulysses12/22/2004 6:25PM Second Polar Orbit
McComas, D. J.; Forsyth, R. J.; Gosling, J. T. +1 more
Ulysses observed well-defined stream interaction regions, SIRs, associated with solar wind stream structure up to a latitude of S65° and shocks to at least a latitude of S71° during the second polar orbit. These SIRs and shocks produced a substantial heliospheric processing of the solar wind. Only a subset of the SIRs recurred on successive solar …
Cosmic-ray Composition as Observed by Ulysses
Connell, James J.
The cosmic ray isotopic composition measurements from the High Energy Telescope (HET) on the Ulysses spacecraft are reviewed. The source isotopic composition of key elements is found to be surprisingly like the Solar system abundances with the notable exception of ^22Ne. The average density of interstellar material cosmic rays traverse is found to…
Time-Dependent 2d Model Compared with Observations During the 1974 Mini Cycle
Wibberenz, G.; Ferreira, S. E. S.; Potgieter, M. S. +1 more
The 1974 mini-cycle is a medium term cosmic ray modulation event with about one year duration. It occurred in an A>0 epoch of solar magnetic polarity during conditions of low activity, but with an increase in the latitudinal extent of the heliospheric current sheet (tilt angle α) and the magnitude B of the heliospheric magnetic field. This cosm…
Fast Dust in the Heliosphere
Grün, E.; Landgraf, M.
The dynamics of dust particles in the solar system is dominated by solar gravity, by solar radiation pressure, or by electromagnetic interaction of charged dust grains with the interplanetary magnetic field. For micron-sized or bigger dust particles solar gravity leads to speeds of about 30 to 40 km s^-1 at the Earth's distance. Smaller particles …
Joint Ulysses and ACE observations of a magnetic cloud and the associated solar energetic particle event
Lario, D.; Forsyth, R. J.; Tappin, S. J. +3 more
On day 49 of 1999 a strong interplanetary shock was observed by the ACE spacecraft located at 1 AU from the Sun. This shock was followed 10 hours later by a magnetic cloud (MC). A large solar energetic particle (SEP) event was observed in association with the arrival of the shock and the MC at ACE. The Ulysses spacecraft, located at 22° S heliolat…
Tracing the magnetic topology of coronal mass ejection events by Ulysses/HI-SCALE energetic particle observations in and out of the ecliptic
Pick, M.; Lanzerotti, L. J.; Sarris, E. T. +3 more
In January 2000, the Ulysses spacecraft observed an ICME event at 43° S heliographic latitude and ∼ 4.1 AU. We use electron (E e>38 keV) observations to trace the topology of the IMF embedded within the ICME. The still controversial issue of whether ICMEs have been detached from the solar corona or are still magnetically anchored to …
The Influence of Tilt Angle and Magnetic Field Variations on Cosmic ray Modulation
Wibberenz, G.; Cane, H. V.; Richardson, I. G. +1 more
The maximum inclination of the heliospheric current sheet (the tilt angle) and the magnitude B of the heliospheric magnetic field are often used to characterize cosmic ray (CR) modulation. The relevance of B is likely to be the coupling of the interplanetary diffusion coefficients K to the field magnitude in a relation K∝ B -n. In this …
Energetic Particle Characteristics in the High-Latitude Heliosphere Near Solar Maximum
Simnett, G. M.
This review is focused on the energetic particle observations made from the Ulysses spacecraft during the period it spent at high latitudes above the streamer belt in 1999/2000. The relativistic electron intensity has exhibited a significant number of impulsive increases, which are attributed to solar flares, up to latitudes of S80° degrees. These…
The Solar and Cosmic-Ray Synodic Periodicity (1969 1998)
Rybák, J.; Kudela, K.; Antalová, A.
The synodic recurrence of the Mt. Wilson plage index (MPSI) and the Calgary cosmic ray (CR) intensity is investigated, using the wavelet power spectra in the range of 18 38 days, during the last three solar cycles. The unique temporal coincidence between the quasi synodic MPSI and the CR periods is detected in 1978 1982 (the 21st solar cycle). In …
Solar Wind Electron Observations Near Solar Maximum at High Latitudes From Thermal Noise Spectroscopy
Moncuquet, Michel; Issautier, Karine; Meyer-Vernet, Nicole +1 more
The Ulysses spacecraft is reaching high heliolatitudes during the approach to solar maximum. We show preliminary in situ electron observations from the URAP experiment, using thermal noise spectroscopy. This method is especially suited to measure accurately the electron density and thermal temperature. The data acquired in the period June Septembe…