Journal article
Auroral electron distributions within and close to the Saturn kilometric radiation source region
Journal of geophysical research. Space physics, Vol.116(A5), pp.05203-n/a
05/2011
DOI: 10.1029/2011JA016461
Abstract
On 17 October 2008, Cassini observed for the first time the electron populations associated with the crossing of a Saturn kilometric radiation source region and its surroundings. These observations allow for the first time the constraint and quantification of the high-latitude acceleration processes, the current systems, and the origin of the low-frequency electromagnetic waves. Enhanced fluxes of field-aligned energetic electrons were measured by the Cassini electron plasma spectrometer in conjunction with unusual intense field-aligned current systems identified using the magnetometer instrument. In the region where downward field-aligned currents were measured, electron data show evidence of two types of upward accelerated electron beams: a broadband energetic (1-100 keV) electron population that is observed throughout the region and a narrow-banded (0.1-1 keV) electron population that is observed sporadically. In the regions where the magnetic field signatures showed evidence for upward field-aligned currents, we observe electron loss cone distributions and some evidence of shell-like distributions. Such nonthermal electron populations are commonly known as a potential free energy source to drive plasma instabilities. In the downward current region, the low-energy and energetic beams are likely the source of the very low frequency emissions. In the upward current region, the shell distribution is identified as a potential source for Saturn kilometric radiation generation via the cyclotron maser instability.
Details
- Title: Subtitle
- Auroral electron distributions within and close to the Saturn kilometric radiation source region
- Creators
- Patricia Schippers - University of IowaChristopher S. Arridge - University College LondonJ. Menietti - University of IowaDonald A. Gurnett - University of IowaLaurent Lamy - Laboratoire d’études spatiales et d’instrumentation en astrophysiqueBaptiste Cecconi - Observatoire de ParisDonald G. Mitchell - Johns Hopkins University Applied Physics LaboratoryNicolas André - Université Fédérale de Toulouse Midi-PyrénéesWilliam S. Kurth - University of IowaS. Grimald - Université Toulouse III - Paul SabatierMichele K. Dougherty - Imperial College LondonA. J. Coates - University College LondonNorbert Krupp - Max Planck Institute for Solar System ResearchDavid T. Young - Southwest Research Institute
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.116(A5), pp.05203-n/a
- DOI
- 10.1029/2011JA016461
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Publisher
- American Geophysical Union/Wiley
- Language
- English
- Date published
- 05/2011
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455266902771
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