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Ulysses in the south polar cap at solar maximum: Heliospheric magnetic field

Balogh, A.; McComas, D. J.; Forsyth, R. J. +1 more

Observations during the recent ascent of Ulysses to the south polar region are reported. Large variations in field magnitude are associated principally with solar wind interaction regions. The observed spiral angle agrees reasonably well with the Parker model. The magnetic flux, the product of the radial field component and the square of the radia…

Generation mechanism for magnetic holes in the solar wind

Tsurutani, B. T.; Goldstein, B. E.; Neugebauer, M. +1 more

A new mechanism for generation of magnetic holes in the solar wind is presented. In the high speed solar wind, large-amplitude right-hand polarized Alfvénic wave packets propagating at large angles to the ambient magnetic field are shown to generate magnetic holes (MHs). Characteristics of these holes crucially depend on plasma β (β being the rati…

An ICME observed by Voyager 2 at 58 AU and by Ulysses at 5 AU

Wang, C.; Heber, B.; von Steiger, R. +1 more

Between days 175 and 180 (June 24 through 29) of 1999, the PLS instrument on Voyager 2 observed alpha particle enhancements with fractional percentages of alpha to proton number densities exceeding 10%. Ulysses (located at 5.3 AU) observed at least two candidate source features for these enhancements. To identify the correct source structure, a 1D…

Solar cycle variations in the electron heat flux: Ulysses observations

Lin, Naiguo; Gary, S. Peter; Scime, Earl E. +2 more

Solar wind observations by the Ulysses spacecraft now include nearly ten years of continuous ion and electron measurements. In this study, we report detailed measurements of the electron heat flux in the solar wind. In particular, we examine the heat flux measurements for long-term correlations with wave activity and solar wind speed. We find that…

Waves close to the crossover frequency in the Jovian middle magnetosphere

Dougherty, Michele K.; Petkaki, Panagiota

The presence of heavy ions in a plasma introduces additional characteristic frequencies one of which is a crossover frequency between each adjacent pair of gyrofrequencies of the ions present. The crossover frequency is controlled by the fractional ion charge densities. The phase speed of the L and R wave modes have the same phase velocity at this…

The influence of the Sun's magnetic field on energetic particles at high heliospheric latitudes

Balogh, A.; Forsyth, R. J.; Goldstein, B. E. +5 more

The first passage of the Ulysses spacecraft to high latitudes was during the declining phase of solar cycle 22. The recent second passage to high latitudes was close to the maximum of solar cycle 23. The axis of the dipolar component of the Sun’s magnetic field was close to 90° from the spin axis, and the coronal neutral line extended up to high l…