Observation of Jupiter's Polar Cusps
Abstract
Global analysis of the HST-STIS data from Jovian auroral observations has revealed the presence of a southern equivalent of the northern transient feature referred to as the northern polar cusp or as an 'auroral flare'. In both hemispheres the features are located near the open/closed field line boundary, and their longitudes follow a constant-magnetic-time profile, near noon, while Jupiter rotates. The spot brightness also varies consistently in both hemispheres. We suggest that these spots are indeed at the footprint of the Jovian polar cusps or in its close vicinity, and that their brightenings are indicative of transient reconnection processes with the interplanetary magnetic field (IMF). A STIS spectrum reveals very penetrating primary particles, possibly up to ~200 keV "equivalent electron energy". This suggests the existence of a very efficient acceleration mechanism along near-cusp magnetic field lines, or of some sort of mixing with plasma from closed outer magnetosphere field lines, as discussed in the case of the Earth.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFMSM22B0236P
- Keywords:
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- 2704 Auroral phenomena (2407);
- 2724 Magnetopause;
- cusp;
- and boundary layers;
- 5737 Magnetospheres (2756);
- 5757 Remote sensing;
- 6220 Jupiter