In:
International Astronomical Union Colloquium, Cambridge University Press (CUP), Vol. 75 ( 1984), p. 551-568
Abstract:
Starting from the assumption that electromagnetic interactions are in some way related to the formation of spokes, it is shown that energy constraints and spoke observations suggest an evolutionary spoke formation model rather than a sudden imprint of an unspecified phenomenon. It is further shown that relatively small (100's km) plasma clouds, interacting both with the magnetosphere and with small dust particles from the ring, can obtain high radial velocities. The “dynamo” which drives the plasma cloud, is a direct result of the difference in the azimuthal velocity components of the corotating plasma and the Keplerian (charged) dust, with its associated azimuthal current. In its wake, the plasma cloud leaves an almost radial trace of sub-micron sized dust elevated above (or below) the ring plane. Finally, the question of the origin of the plasma clouds is addressed. There could be several processes, e.g. meteorite impacts, electric discharges in the ring, particle acceleration along parallel electric fields etc. Each process has its own characteristic signature, and more work (analysis of measurements and theory) is needed to differentiate between them.
Type of Medium:
Online Resource
ISSN:
0252-9211
DOI:
10.1017/S0252921100101630
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1984
