title: Over the southern solar pole: low-energy interplanetary charged particles.
abstract: The heliosphere instrument for spectrum, composition, and anisotropy (HISCALE) recorded the fluxes of low-energy ions and electrons (> 50 kiloelectron volts) when Ulysses crossed the southern solar polar region and revealed that the large-scale structure of the heliosphere to at least approximately -75 degrees was significantly influenced by the near-equatorial heliospheric current sheet. Electrons in particular were accelerated by the current sheet-produced and poleward-propagating interplanetary reverse shock at helioradii far from the Ulysses location. At heliolatitudes higher than approximately -75 degrees on the Ulysses ascent to the pole and approximately -50 degrees on the descent, small, less regular enhancements of the lowest energy electron fluxes were measured whose relations to the current sheet were less clear. The anomalous component of low-energy (approximately 2 to 5 megaelectron volts per nucleon) oxygen flux at the highest heliolatitudes was found to be approximately 10(-8) [per square centimeter per second per steradian (per kiloelectronvolt per nucleon)]; the anomalous Ne/O ratio was approximately 0.25.
authors.affiliation: AT&T Bell Laboratories, Murray Hill, NJ 07974, USA.
authors.forename: L J
authors.initials: LJ
authors.lastname: Lanzerotti
authors.forename: T P
authors.initials: TP
authors.lastname: Armstrong
authors.forename: R E
authors.initials: RE
authors.lastname: Gold
authors.forename: C G
authors.initials: CG
authors.lastname: Maclennan
authors.forename: E C
authors.initials: EC
authors.lastname: Roelof
authors.forename: G M
authors.initials: GM
authors.lastname: Simnett
authors.forename: D J
authors.initials: DJ
authors.lastname: Thomson
authors.forename: K A
authors.initials: KA
authors.lastname: Anderson
authors.forename: S E
authors.initials: SE
authors.lastname: Hawkins
authors.forename: S M
authors.initials: SM
authors.lastname: Krimigis
mesh_terms: D004583:Electrons; D005118:Extraterrestrial Environment; D007477:Ions; D010100:Oxygen; D016082:Solar System; D018531:Spacecraft
chemical_list: D007477:Ions; D010100:Oxygen