Search Publications
Solar wind stream interfaces in corotating interaction regions: SWICS/Ulysses results
Wimmer-Schweingruber, Robert F.; von Steiger, Rudolf; Paerli, Raoul
Motivated by the well-known differences in charge state and even elemental composition of the slow solar wind as compared to high-speed streams, we have analyzed observations made by the Solar Wind Ion Composition Spectrometer (SWICS)/Ulysses mass spectrometer of the series of corotating interaction regions (CIRs) encountered by Ulysses in 1992/19…
A two-dimensional simulation of the radial and latitudinal evolution of a solar wind disturbance driven by a fast, high-pressure coronal mass ejection
Riley, Pete; Gosling, J. T.; Pizzo, V. J.
Using a hydrodynamic simulation, we have studied the two-dimensional (symmetry in the azimuthal direction) evolution of a fast, high-pressure coronal mass ejection (CME) ejected into a solar wind with latitudinal variations similar to those observed by Ulysses. Specifically, the latitudinal structure of the ambient solar wind in the meridional pla…
Mars surface mineralogy from Hubble Space Telescope imaging during 1994-1995: Observations, calibration, and initial results
Bell, James F.; Wolff, Michael J.; Clancy, R. Todd +3 more
Visible to near-infrared observations of Mars were made with the Hubble Space Telescope (HST) during 1994-1995 with the goals of monitoring seasonal variability of the surface and atmosphere and mapping specific spectral units to constrain the planet's surface mineralogy. This paper presents the details of the collection and calibration of the dat…
Direct observational evidence for a heliospheric magnetic field with large excursions in latitude
Schwadron, N. A.; Zurbuchen, T. H.; Fisk, L. A.
Fisk has pointed out that the heliospheric magnetic field in fast solar wind, that is, at the higher heliographic latitudes, may undergo large excursions in heliographic latitudes, and thus that the field will deviate from the expected Archimedes spiral pattern. These excursions result from the interplay between the nonradial expansion of the sola…
Magnetopause structure and the role of reconnection at the outer planets
Russell, C. T.; Szabo, A.; Le, G. +1 more
In situ measurements have been obtained at the magnetopause boundary of all the giant outer planets. The Jovian magnetopause was probed by Pioneers 10 and 11, Voyagers 1 and 2, Ulysses, and most recently by Galileo. Saturn was visited by Pioneer 11 and Voyagers 1 and 2, and Uranus and Neptune were visited by Voyager 2. The observations at Jupiter …
Hot protons in the inner corona and their effect on the flow properties of the solar wind
Habbal, Shadia R.; Hollweg, Joseph V.; Esser, Ruth +1 more
Following recent observations which indicate the presence of extremely high flow speeds in the inner corona, 700-800kms-1 below 10RS, and the possible presence of very high proton temperatures, 3×106<=Tp<=8.5×106K, we present a parameter study which shows that if the high proton temperat…
Coronal streamer belt asymmetries and seasonal solar wind variations deduced from Wind and Ulysses data
Steinberg, J. T.; Crooker, N. U.; Smith, E. J. +4 more
Solar wind measurements from Wind during March 1995 are combined with those from Ulysses' fast latitude scan to construct a map of the streamer belt. On the timescale of coronal change, the map is nearly a snapshot view of solar wind speed contours threaded by the trace of the heliospheric current sheet (HCS) in the +/-30° heliolatitude range. The…
Experimental constraints on pulsed and steady state models of the solar wind near the Sun
Habbal, S. R.; Wang, Y. -M.; Feldman, W. C. +1 more
Ulysses observations of the high-latitude solar wind were combined with Spartan 201 observations of the corona to investigate the nature and extent of uncertainties in our knowledge of solar wind structure near the Sun. In addition to uncertainties stemming from the propagation of errors in density profiles inferred from coronagraph observations […
A comparative study of cosmic ray radial and latitudinal gradients in the inner and outer heliosphere
Kunow, H.; Wibberenz, G.; Heber, B. +6 more
The radial and latitudinal intensity gradients of 145-255 MeV/nucleon He, 34-50 MeV/nucleon He and 30-69 MeV H are studied over an extensive range of heliocentric distances and latitudes for the 1993.0-1996.0 time period using data from cosmic ray experiments on the Ulysses, IMP 8, Voyager 1 and 2, and Pioneer 10 spacecraft. The radial gradients a…
Influence of heavy ions on the high-speed solar wind
Li, Xing; Habbal, Shadia R.; Esser, Ruth +1 more
We present the results of a parameter study of the influence of heavy ions on the background solar wind, choosing doubly ionized helium, or alpha particles, and O+6, as examples. Using a three-fluid solar wind model, we keep the input parameters to the electrons and protons unchanged and investigate the effects of changing the input ene…