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Interplanetary discontinuities and Alfvén waves at high heliographic latitudes: Ulysses
Balogh, A.; Goldstein, B. E.; Neugebauer, M. +5 more
This paper presents the results of the first statistical study of interplanetary directional discontinuities at both low and high heliographic latitudes measured by the Ulysses magnetometer. There is a gradual decrease in the rate of occurrence of interplanetary discontinuities (ROIDs) with increasing radial distance. From 1 to 5 AU, an e-(r-…
The underlying Parker spiral structure in the Ulysses magnetic field observations, 1990-1994
Balogh, A.; McComas, D. J.; Forsyth, R. J. +2 more
The fundamental aim of the Ulysses space mission is to extend our understanding of the heliosphere into three dimensions. By April 1994 the spacecraft had reached a heliographic latitude of 60°S. Hourly averages of the Ulysses heliospheric magnetic field observations have been analyzed to determine to what extent the underlying field direction wit…
Global imaging of Mars by Hubble space telescope during the 1995 opposition
Bell, James F.; Wolff, Michael J.; Clancy, R. Todd +3 more
Hubble space telescope (HST) imaging of Mars near the 1995 opposition resulted in excellent synoptic-scale images of the planet during the spring season in the northern hemisphere. Because this season coincides with the aphelion position of Mars in its orbit, it is therefore the most difficult for ground based observation because of the relatively…
Heliospheric plasma sheets as small-scale transients
Balogh, A.; Crooker, N. U.; Burton, M. E. +2 more
Ulysses plasma and magnetic field data from the ecliptic plane near 1 AU signaling multiple heliospheric plasma sheets across a sector boundary are analyzed in order to determine their geometrical configuration. The plasma sheets coincided with a region of sporadic heat flux dropouts and planar magnetic structure. The plane of the structure was in…
Properties of arc-polarized Alfvén waves in the ecliptic plane: Ulysses observations
Balogh, A.; Tsurutani, B. T.; Forsyth, R. J. +3 more
Ulysses observations of the interplanetary magnetic field reveal well-ordered rotations on the timescale of several hours. These have been previously identified as ``arc-polarized'' Alfvén waves. Rotational discontinuities (RDs) are often an integral part of the wave. This study focuses on a statistical description of these rotations (ARCs) in the…
Plasma flow in the Jovian magnetosphere and related magnetic effects: Ulysses observations
Dougherty, M. K.; Balogh, A.; Forsyth, R. J. +6 more
The plasma flow in Jupiter's magnetosphere observed during the Ulysses flyby is compared with previous Pioneer, Voyager and ground-based observations. These data show that near-rigid corotation is enforced in the inner magnetosphere, but that the azimuthal flow plateaus at 150-300 kms-1 in the middle magnetosphere plasma sheet beyond ~2…
Mars ozone measurements near the 1995 aphelion: Hubble space telescope ultraviolet spectroscopy with the faint object spectrograph
Wolff, Michael J.; Clancy, R. Todd; James, Philip B. +4 more
Ultraviolet (225-330 nm) spectral scans of Mars were obtained with the Hubble space telescope (HST) faint object spectrograph (FOS) in February of 1995. These spectra yield ozone column abundances, cloud opacities (0.2-0.4 at low latitudes), and polar seasonal ice albedos from southern midlatitudes to northern high latitudes on Mars. At the time o…
Perpendicular transport in shock acceleration
Giacalone, J.; Jokipii, J. R.
We consider the foundations of charged-particle acceleration at collisionless shocks in which the average magnetic field is perpendicular to the shock-normal direction. Our shock model, which is a numerical integration of the trajectories of an ensemble of test particles in specified shock fields, includes an isotropic and homogeneous, Kolmogorov-…
Ulysses observations of whistler waves at interplanetary shocks and in the solar wind
Forsyth, R.; Balogh, A.; MacDowall, R. J. +4 more
This study of whistler wave emission observed by the Ulysses Unified Radio and Plasma Wave (URAP) experiment between 1 and 5 AU is a complement to previous studies of whistler waves observed by the Helios spacecraft between 0.3 and 1 AU. The Helios spacecraft continuously detected a background of whistlers close to the Sun, and this background was…
The tilts of corotating interaction regions at midheliographic latitudes
Riley, Pete; Gosling, J. T.; Pizzo, V. J. +1 more
Previous analysis of midlatitude corotating interaction regions (CIRs) observed by Ulysses in the southern heliosphere has revealed that the flow downstream of the forward (F) shock (or wave) on the leading edge of a CIR generally turns northward and into the direction of planetary motion (westward), while the flow downstream of the reverse (R) sh…