Quasi-periodic emissions (15-80 min) from the poles of Jupiter as a principal source of the large-scale high-latitude magnetopause boundary layer of energetic particle

In this study, we concentrate on the examination of the quasi-periodic behavior of 0.5-1.6 MeV (similar to40-400 keV) protons (electrons) and of relativistic ( > 16 MeV) electrons, observed at Jupiter by two different experiments onboard Ulysses, the HI-SCALE and COSPIN, respectively, within the large-scale south duskside magnetopause boundary layer (MPBL) of energetic particles, from similar to 20: 00 UT, day 41, to 12: 00 UT, day 43. During those times, the observations confirm the transition of Ulysses to an important magnetospheric region with particle intensities comparable to the magnetodisk levels. A careful analysis of high time-resolution intensity, anisotropy and spectral measurements suggests the following: (1) The quasi-periodic similar to40 min (QP-40) energetic electron (> similar to40 keV) and proton ( > similar to 0.5 MeV) emissions from the south pole were a characteristic phenomenon in the south duskside MPBL; an almost continuous QP 40-min variation has been confirmed in energetic electron observations. (2) When the QP-40 modulation was not evident in energetic particle intensities, it was still detectable in spectral and anisotropy observations. (3) The QP-40 emission is a principal, but not the only periodic, energetic electron and proton emission; other periodicities (similar to 15, similar to 20, similar to 30, similar to 50, similar to 60, similar to 80 min) were also significant in energetic particle spectral and anisotropy observations. We infer that QP-40 emissions along with other periodic emissions (similar to15, similar to 20, similar to 30, similar to 50, similar to 60, similar to 80 min) were the principal source of the large-scale high-latitude MPBL of energetic particles during Ulysses outbound pass of Jupiter. (C) 2003 Elsevier Ltd. All rights reserved.