Supercorotating return flow from reconnection in Saturn's magnetotail

Masters, A. and Thomsen, M. F. and Badman, S. V. and Arridge, C. S. and Young, D. T. and Coates, A. J. and Dougherty, M. K. (2011) Supercorotating return flow from reconnection in Saturn's magnetotail. Geophysical Research Letters, 38 (3). ISSN 0094-8276

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Abstract

Detecting plasma dynamics in Saturn's magnetosphere is essential for understanding energy flow through the system. It has been proposed that both the Dungey and Vasyliunas cycles operate at Saturn, and the competition between these cycles has been debated. We examine data taken by the Cassini spacecraft in Saturn's post-dawn magnetosphere, ∼17.5 Saturn radii from the planet, and identify an example of return flow from magnetotail reconnection. The flow included water group ions and had elevated ion temperatures (of order 1 keV), consistent with Vasyliunas cycle return flow. The flow was also supercorotating (∼200 km s−1, ∼120% of corotation), which is highly atypical of Saturn's outer magnetosphere. Our results suggest that return flows are time-variable, and our results concerning Dungey cycle return flows are inconclusive. We propose that supercorotating flows in Saturn's dawn magnetosphere strongly influence the current system that is responsible for the planet's main auroral emission.

Item Type:
Journal Article
Journal or Publication Title:
Geophysical Research Letters
Additional Information:
Copyright 2011 by the American Geophysical Union.
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/asjc/1900
Subjects:
ID Code:
67088
Deposited By:
Deposited On:
10 Oct 2013 15:12
Refereed?:
Yes
Published?:
Published
Last Modified:
14 Jul 2020 03:41