title: Jupiter's Magnetosphere: Plasma Description from the Ulysses Flyby.
abstract: Plasma observations at Jupiter show that the outer regions of the Jovian magnetosphere are remarkably similar to those of Earth. Bow-shock precursor electrons and ions were detected in the upstream solar wind, as at Earth. Plasma changes across the bow shock and properties of the magnetosheath electrons were much like those at Earth, indicating that similar processes are operating. A boundary layer populated by a varying mixture of solar wind and magnetospheric plasmas was found inside the magnetopause, again as at Earth. In the middle magnetosphere, large electron density excursions were detected with a 10-hour periodicity as planetary rotation carried the tilted plasma sheet past Ulysses. Deep in the magnetosphere, Ulysses crossed a region, tentatively described as magnetically connected to the Jovian polar cap on one end and to the interplanetary magnetic field on the other. In the inner magnetosphere and lo torus, where corotation plays a dominant role, measurements could not be made because of extreme background rates from penetrating radiation belt particles.
authors.forename: S J
authors.initials: SJ
authors.lastname: Bame
authors.forename: B L
authors.initials: BL
authors.lastname: Barraclough
authors.forename: W C
authors.initials: WC
authors.lastname: Feldman
authors.forename: G R
authors.initials: GR
authors.lastname: Gisler
authors.forename: J T
authors.initials: JT
authors.lastname: Gosling
authors.forename: D J
authors.initials: DJ
authors.lastname: McComas
authors.forename: J L
authors.initials: JL
authors.lastname: Phillips
authors.forename: M F
authors.initials: MF
authors.lastname: Thomsen
authors.forename: B E
authors.initials: BE
authors.lastname: Goldstein
authors.forename: M
authors.initials: M
authors.lastname: Neugebauer