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Ulysses and WIND particle observations of the November 1997 solar events

Lario, D.; Balogh, A.; Maksimovic, M. +5 more

The episode of intense solar activity on 4 and 6 November 1997 resulted in large and extended particle events observed by the Ulysses and WIND spacecraft. Ulysses was at a heliocentric distance of 5.34 AU, very close to the solar equator and 100° west in heliolongitude from earth. WIND was near the earth at 0.99 AU from the Sun and in the ecliptic…

Quasi-periodic behavior of ion events and wave activity upstream from Jupiter's Bow Shock: Ulysses' observations

Balogh, A.; Sarris, E. T.; Anagnostopoulos, G. C. +3 more

A new insight into the ways that the Jovian magnetosphere influences the near Jupiter interplanetary space becomes possible thanks to Ulysses' collection of magnetic field, plasma and energetic ion (HI-SCALE) data during its inbound trajectory (d22-d34, 1992). The most striking new results from the analysis of those data are the following: a) pres…

Jovian radio “bullseyes” observed by Ulysses

MacDowall, R. J.; Kaiser, M. L.

We report the observation of extremely rare semi-bullseye or target-like features in the dynamic spectra of Jupiter obtained in 1991-1994 by the Ulysses Unified Radio and Plasma wave instrument. The emissions lie in the 20-50 kHz band and consist of narrow band (∼1-2 kHz) semi-concentric wisps on frequency-time dynamic spectra. The individual wisp…

Interstellar pickup hydrogen observations at large heliocentric distances

Gazis, P. R.; Mihalov, J. D.

Possible signatures of interstellar pickup hydrogen have been identified in data from the Pioneer 10 and 11 Ames plasma analyzers at locations out to beyond the orbit of Saturn, and at a wide range of longitudes in the heliosphere, both upstream and downstream in the interstellar wind. These signatures provide an extension of pickup ion observatio…

Polar plumes and fine-scale coronal structures - On the interpretation of coronal radio sounding data

Pätzold, M.; Bird, M. K.

Variations in total electron content at high heliographic latitudes, observed during the 1995 solar conjunction of the Ulysses spacecraft when the radio ray path was embedded in the southern coronal hole, were interpreted by Woo and Habbal [1997b] as polar plume structures extending to at least 30 solar radii from the Sun. Somewhat surprisingly, w…

Low energy anomalous ions at northern heliolatitudes

Lanzerotti, L. J.; Maclennan, C. G.

Measurements of the anomalous component of nitrogen, oxygen, and neon ions (∼0.5-8 MeV/nucl.) at northern heliolatitudes by the HI-SCALE instrument on the Ulysses spacecraft show that the energy spectra of these ions are essentially flat from the highest heliolatitudes (80° N) to near the ecliptic plane. For energies from 1-8 MeV/nucl., the northe…

Observations of galactic cosmic ray modulation during Earth-directed coronal mass ejections

Valtonen, E.; Riihonen, E.; Teittinen, M. +3 more

We describe three cosmic-ray decreases observed by the energetic particle telescope ERNE on board SOHO spacecraft during the period January-May, 1997. The decreases in cosmic-ray proton intensities in the energy range above 50 MeV were observed after the passage of interplanetary shocks on February 9, April 10, and May 15. All the shocks were prod…

Comment on: “Polar plumes and fine-scale coronal structures — On the interpretation of coronal radio sounding data” by Pätzold and Bird

Habbal, Shadia Rifai; Woo, Richard

The solar wind alpha-particle content as a clue for the origin of slow flows

Bavassano, B.; Pietropaolo, E.; Bruno, R.

Some aspects of the variation of the alpha-particle abundance in the solar wind are studied using Ulysses data. We focus on the first mid-latitude phase of the mission, when the spacecraft intermittently enters the fast high-latitude wind, and on the region around the first perihelion passage, when low-latitude wind in conditions of low solar acti…

Wave power dropouts associated with radial field intervals in high speed solar wind

Balogh, A.; McComas, D. J.; Horbury, T. S. +1 more

Examination of 770 days of heliospheric magnetic field data recorded within polar solar wind by the Ulysses spacecraft revealed a number of occasions when the wave power decreased by more than an order of magnitude for several hours. These power dropouts were found to be associated with intervals when the magnetic field was closely aligned with th…