Ulysses paper

Planet. Space Sci., 44, 341, 1996

Abstract:
Observations of ~MeV ions obtained in Jupiter's magnetosphere with the COSPIN Anisotropy Telescope instrument during Ulysses' encounter with Jupiter in Feburary 1992 are presented. Ulysses is the fifth spacecraft to have visited Jupiter's magnetosphere, all of which approached Jupiter from the mid-morning sector close to the equatorial plane. Ulysses' outbound pass was, however, through a previously unexplored region of the dusk meridian at moderate southerly latitudes. The jovian magnetosphere has proved very variable, and the particle anisotropy seen during Ulysses' visit is of very different character to that seen on previous visits, even on the inbound pass. A time series of three-dimensional anisotropy of ~MeV protons is presented. The first-order anisotropy transverse to the field can be caused either by a bulk flow of the plasma (i.e. a Compton-Getting anisotropy). or by a spatial gradient in the flux, or by some combination of both. The plasma bulk velocity and the flux gradient scale length based on these alternative interpretations are presented, and the plausibility, or otherwise of each are commented on.

For copies of this paper, please contact us.