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OH in Saturn's magnetosphere: Observations and implications
Richardson, J. D.; McGrath, M. A.; Eviatar, A. +1 more
The discovery of OH in Saturn's inner magnetosphere changed our view of this region from one where plasma dominated the physics to one where neutrals are dominant. We revisit Hubble Space Telescope observations of OH and derive revised OH brightnesses for observations in 1992, 1994, and 1995. These OH observations as well as Voyager observations a…
Ulysses' rapid crossing of the polar coronal hole boundary
Forsyth, R.; Balogh, A.; McComas, D. J. +2 more
The Ulysses spacecraft crossed from the slow dense solar wind characteristic of the solar streamer belt into the fast, less dense flow from the northern polar coronal hole over a very short interval (several days) in late March 1995. The spacecraft, which was at 1.35 AU and ~19° north heliographic latitude, moving northward in its orbit, remained …
Global model of the corona with heat and momentum addition
Wu, S. T.; Poletto, G.; Suess, S. T. +1 more
We have been developing a series of global coronal models directed at a better simulation of empirical coronal hole and streamer properties. In a previous study, a volumetric heat source was used to produce a thin current sheet above streamers and high solar wind speed in the coronal hole. This improved the preexisting coronal structure for corona…
Solar wind measurements with SOHO: The CELIAS/MTOF proton monitor
Hsieh, K. C.; Wurz, P.; Bochsler, P. +26 more
The proton monitor, a small subsensor in the Charge, Element, and Isotope Analysis System/Mass Time-of-Flight (CELIAS/MTOF) experiment on the SOHO spacecraft, was designed to assist in the interpretation of measurements from the high mass resolution main MTOF sensor. In this paper we demonstrate that the proton monitor data may be used to generate…
Thermal coupling of protons and neutral hydrogen in the fast solar wind
Habbal, Shadia R.; Allen, Lorraine A.; Hu, You Q.
We investigate the coupling between neutral hydrogen atoms and protons in the corona for a range of proton temperatures reaching a maximum of 6×106K, as recently inferred from observations of the Ly α spectral line profiles by Kohl et al. [1996]. We adopt the approach used by Olsen et al. [1994], whereby the neutral hydrogen atoms are t…
Kinetic properties of solar wind minor ions and protons measured with SOHO/CELIAS
Wurz, P.; Bochsler, P.; Geiss, J. +14 more
Using observations of the Charge Time-of-Flight (CTOF) charge and mass spectrometer of the Charge, Element and Isotope Analysis System (CELIAS), and of CELIAS/proton monitor on board the Solar and Heliospheric Observatory (SOHO), we present an overview of speeds and kinetic temperatures of minor ions and protons in the solar wind near solar minimu…
Electron temperature in the solar wind: Generic radial variation from kinetic collisionless models
Issautier, Karine; Meyer-Vernet, Nicole
We calculate analytically the radial profile of the average electron temperature in the solar wind with a kinetic collisionless model. The electron temperature profile at large distances r is the sum of a term ~r-4/3 plus a constant, with both terms of the same order of magnitude near r~1AU. This result is generic as it is weakly depend…
Type III radio source located by Ulysses/Wind triangulation
Kaiser, M. L.; Stone, R. G.; Fainberg, J. +1 more
Radio triangulation from the widely separated Ulysses and Wind spacecraft is used to reconstruct the trajectory of a type III radio burst in the three-dimensional heliosphere. The derived radio trajectory follows a (Parker) spiral path corresponding to a solar wind speed of ~200km/s and progresses to the south of the ecliptic plane. These remote r…
Saturn's hydrogen aurora: Wide field and planetary camera 2 imaging from the Hubble Space Telescope
Krist, John E.; Holtzman, Jon A.; Trauger, John T. +8 more
Wide field and planetary camera 2/Hubble Space Telescope (WFPC2/HST) images of Saturn's far ultraviolet aurora reveal emissions confined to a narrow band of latitudes near Saturn's north and south poles. The aurorae are most prominent in the morning sector with patterns that appear fixed in local time. The geographic distribution and vertical exte…
Very low frequency waves in the heliosphere: Ulysses observations
Balogh, A.; McComas, D. J.; Forsyth, R. J. +5 more
An overall profile of plasma wave activity in a frequency range of 0.2 to 448 Hz in the solar wind is presented using 6 years of Ulysses data which cover a large range of heliographic latitudes (0° to +/-80°) at distances from 1 to 5 AU from the Sun. The spacecraft has continuously observed wave activity with peak power below the local electron cy…