Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model

Details Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model

May 2008

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2008agusmsm41b..03s&link_type=abstract

American Geophysical Union, Spring Meeting 2008, abstract #SM41B-03

Physics

2407 Auroral Ionosphere (2704), 2431 Ionosphere/Magnetosphere Interactions (2736), 2463 Plasma Convection (2760), 5443 Magnetospheres (2756), 6275 Saturn

Scientific paper

We describe a model initially presented by Sittler et al. [2006] which attempts to explain the global response of Saturn's magnetosphere and its corresponding auroral behavior to variations in the solar wind. The model was derived from published simultaneous Hubble Space Telescope (HST) auroral images and Cassini upstream measurements taken during the month of January 2004. These observations show a direct correlation between solar wind dynamic pressure and (1) auroral brightening toward dawn local time, (2) an increase of rotational movement of auroral features to as much as 75% of the corotation speed, (3) the movement of the auroral oval to higher latitudes and (4) an increase in the intensity of Saturn Kilometric Radiation (SKR). This model is an alternative to the reconnection model of Cowley et al. [2004a,b; 2005] which is more Earth like while ours stresses rotation. If angular momentum is conserved in a global sense, then when compressed the magnetosphere will tend to spin up and when it expands will tend to spin down. With the plasma sheet outer boundary at L ~ 15 we argue this region to be the dominant source region for the precipitating particles. If radial transport is dominated by centrifugal driven flux tube interchange motions, then when the magnetosphere spins up, outward transport will increase, the precipitating particles will move radially outward and cause the auroral oval to move to higher latitudes as observed. The Kelvin-Helmholtz instability may contribute to the enhanced emission along the dawn meridian as observed by HST. We present this model in the context of presently published observations by Cassini. 1. Sittler, E. C., M. F. Blanc and J. D. Richardson, JGR, Vol. 111, A06208, 2006 2. Cowley, S. W., et al., Ann. Geophys., Vol. 22, 1379, 2004a 3. Cowley, S. W., et al., JGR, Vol. 109, A05212, 2004b. 4. Cowley, S. W., et al., JGR, Vol. 110, A02201, 2005.

Affiliated with

Also associated with

No associations

Rating

Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Saturn's Auroral Response to the Solar Wind: Centrifugal Instability Model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1401028