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Ulysses measurements of variations in the solar wind-interstellar hydrogen charge exchange rate
McComas, D. J.; Gosling, J. T.; Pryor, W. R. +1 more
Charge exchange with solar wind protons is the primary ionization process for interstellar hydrogen traveling through the heliosphere. In this study we use Ulysses solar wind observations to examine and quantify variations in charge exchange. We find that these variations are largest within stream interaction regions where the charge exchange rate…
Radial evolution of density structure in the solar corona
Habbal, Shadia Rifai; Woo, Richard
White-light measurements made by the SOHO coronagraphs (LASCO for Large Angle Spectrometric Coronagraph) and the HAO Mauna Loa Mk III K-coronameter are combined to follow the evolution of path-integrated density structure in the solar corona overlying both coronal hole and quiet Sun regions from 1.15 to 5.5 Ro. The global imaging provid…
Observations of heliospheric planar and offset-planar magnetic structures
Balogh, A.; Jones, G. H.; Horbury, T. S.
Planar magnetic structures are regions of solar wind plasma where the magnetic field orientation is constrained within a fixed plane for durations of several hours. Within these structures, magnetic field discontinuities are seen, with the discontinuity surfaces being almost co-planar. The results of a survey of planar magnetic strutures detected …
The electron heat flux in the polar solar wind: Ulysses observations
Scime, Earl E.; Littleton, J. E.; Badeau, Allen E., Jr.
Ulysses measurements of the solar wind electron heat flux as a function of heliographic latitude are presented. Contamination from a light leak at the highest latitudes has been removed from the data by interpolating between uncontaminated pixels. After normalization by the radial gradient in the electron heat flux obtained during the inecliptic p…
Energetic particle abundances at CIR shocks
Fränz, M.; Keppler, E.; Mason, G. M. +3 more
The forward and reverse shocks that bound corotating interaction regions (CIRs) travel into different solar wind regimes. In order to test whether the energetic ions associated with the CIR shocks reflect the ambient solar wind, we investigate the elemental composition of 0.1-4.0 MeV/N ions in CIRs observed from 1 to 5 AU with instrumentation on b…
Current sheet control of recurrent particle increases at 4-5 AU
Lario, D.; Balogh, A.; Maksimovic, M. +5 more
We examine the relation between the current sheet as derived from observations of the Sun's neutral line, and recurrent particle increases associated with co-rotating interactions regions (CIR) at 4 to 5 AU radial distance as observed by the Ulysses spacecraft during its first out-of-ecliptic orbit around the Sun. We compare observations during th…
Coronal magnetic field topology and source of fast solar wind
McComas, D.; Guhathakurta, M.; Thompson, B. +2 more
We have developed a steady state, 2D semi-empirical MHD model of the solar corona and the solar wind with many surprising results. This model for the first time shows, that the boundary between the fast and the slow solar wind as observed by Ulysses beyond 1 AU, is established in the low corona. The fastest wind observed by Ulysses (680-780 km/s) …
Correction to “The interplanetary events of January-May, 1997 as inferred from energetic particle data, and their relationship with solar events”
St. Cyr, O. C.; Cane, H. V.; Richardson, I. G.
O-Mode Emission at the Io Torus: A Real or Virtual Source?
MacDowall, R. J.; Farrell, W. M.; Hess, R. A.
We examine the nature of an ordinary (o-mode) emission observed near the Io plasma torus during the 1992 Ulysses encounter with Jupiter. The emission appears to intensify by factors of 10-100 in local torus density depletions. We examine whether these intensifications are due to local generation within the density depletion or reflection of a remo…