Search Publications
Origins of Anisotropic 40 300 keV Electron Events Observed at Low and High Latitudes
Pick, M.; Gold, R. E.; Hawkins, S. E., III +1 more
Using a survey of anisotropic electron events in the energy range of ∼40 300 keV observed by HI-SCALE on Ulysses, we have selected several time intervals during 1999 when Ulysses traveled from about 20° S at 5.2 AU (January 1999) to 42° S at 4.2 AU (January 2000). We compare these events with observations at ∼1 AU using the nearly identical instru…
Oxygen and Iron Ions at High Heliolatitudes
Lanzerotti, L. J.; Gold, R. E.; Maclennan, C. G.
The fluxes of O and Fe ions at high heliolatitudes measured by the HiScale instrument on Ulysses reflect the dynamical processes that affect the charged particle populations in the heliosphere. Both the O and Fe ions show more latitude dependence in the first (solar minimum) orbit to high southern heliolatitudes than during the second (solar maxim…
The influence of the Sun's magnetic field on energetic particles at high heliospheric latitudes
Balogh, A.; Forsyth, R. J.; Goldstein, B. E. +5 more
The first passage of the Ulysses spacecraft to high latitudes was during the declining phase of solar cycle 22. The recent second passage to high latitudes was close to the maximum of solar cycle 23. The axis of the dipolar component of the Sun’s magnetic field was close to 90° from the spin axis, and the coronal neutral line extended up to high l…
Source Region of High and Low Speed Wind during the Spartan 201-05 Flight
Skoug, Ruth; Kucera, Therese; Fisher, Richard +4 more
The large-scale coronal magnetic fields of the Sun are believed to play an important role in organizing the coronal plasma and channeling the high and low speed solar wind along the open magnetic field lines of the polar coronal holes and the rapidly diverging field lines close to the current sheet regions, as has been observed by the instruments …
Four point measurements of electrons using PEACE in the high-altitude cusp
Coates, A. J.; Wilson, R. J.; Owen, C. J. +8 more
We present examples of electron measurements from the PEACE instruments on the Cluster spacecraft in the high-latitude, high-altitude region of the Earth's magnetosphere. Using electron density and energy spectra measurements, we examine two cases where the orbit of the Cluster tetrahedron is outbound over the northern hemisphere, in the afternoon…
Compressive-Diffusive Acceleration of Energetic Charged Particles
Giacalone, J.; Jokipii, J. R.; Kota, J.
We discuss the phenomenon of the acceleration of charged particles in a compressing di~@usive medium and apply it to recent ACE observations in the interplanetary medium. It has been recognized that the phenomenon of di~@usive shock acceleration can readily be generalized to the case where the the shock isreplaced by a gradual change in the veloci…
Dopplershifts in the solar transition region
Vial, J. -C.; Gontikakis, C.; Alissandrakis, C. E. +2 more
We study the dynamics of the quiet sun transition region, using observations obtained with the SOHO CDS/NIS and SUMER spectrographs. We examine the morphology of the network as a function of temperature and we compare the intensity features with those of the dopplergrams. The velocity distributions have a different behaviour for the bright feature…
Characteristics of a type II solar radio burst on 22 March 1998
Shanmugaraju, A.; Umapathy, S.; Balasubramanian, V.
A solar radio type II burst (which was seen as two patches of emission, one during 07:00-07:13 UT and other one during 07:20-07:35 UT) was observed on 22 March 1998 using the Madurai radio spectrograph. A broad range of data (from Culgoora and Hiraiso spectrographs, white-light data from SOHO/LASCO and X-ray data from Yohkoh and GOES satellites) w…
Ground-Based Observations of the 10 August 1995 Saturn Ring-Plane Crossing
Nicholson, Philip D.; Matthews, Keith; McGregor, Peter J. +2 more
Observations at 2.3 µm at the Australian National University 2.3-m telescope at Siding Spring Observatory and the 5-m Hale telescope at Palomar Observatory from 9 to 17 August provide a longer baseline of time around the 10 August 1995 Saturn ring-plane crossing than space-based observations. The edge-on photometric thickness of the rings at…
Cosmic ray and solar particle composition measurements in the southern solar polar region
Sanderson, T. R.; Marsden, R. G.; Tranquille, C. +2 more
This analysis is based on energetic particle measurements covering the energy range 4-20 MeV/n recorded by the COSPIN/LET instrument on the Ulysses spacecraft. Around the end of the year 2000 the Ulysses spacecraft was above the southern polar region at less than 2.5 AU radial distance from the Sun. A preliminary analysis has shown that the abunda…