HR: 1340h
AN: SM53A-1090    [Abstracts]
TI: Effect of Field-Aligned Potentials on Angular Momentum Transfer at Jupiter
AU: * Ray, L C
EM: licia.ray@colorado.edu
AF: Laboratory for Atmospheric and Space Physics University of Colorado - Boulder, UCB392, Boulder, CO 80309, United States
AU: Ergun, R E
EM: ree@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics University of Colorado - Boulder, UCB392, Boulder, CO 80309, United States
AU: Delamere, P A
EM: delamere@lasp.colorado.edu
AF: Laboratory for Atmospheric and Space Physics University of Colorado - Boulder, UCB392, Boulder, CO 80309, United States
AU: Bagenal, F
EM: bagenal@colorado.edu
AF: Laboratory for Atmospheric and Space Physics University of Colorado - Boulder, UCB392, Boulder, CO 80309, United States
AB: We present a time-independent model of Jupiter's rotationally driven aurora based on angular momentum conservation including the effects of a field-aligned potential and a variable Pedersen conductivity. We modify our existing model to include the momentum transfer within Jupiter's neutral atmosphere. The field-aligned potential arises from field-aligned current limitation at high-latitude and changes the mapping of the electric fields between the ionosphere and the magnetosphere. The primary effect of the field-aligned potential is to actually enhance coupling by increasing current flow from the ionosphere to the magnetosphere. The net result is an equatorial mapping location for the main auroral oval at ~25 R_J. Our model reproduces many of the observed characteristics of Jupiter's main auroral oval including the energy flux into the ionosphere (~2 to ~30 mW/m²), the width of the aurora at the ionosphere (~1000 km), and field-aligned potentials consistent with the observed electron energies (~30 to ~200 keV). We also investigate the effect of the magnetic field geometry on the total radial current produced and present preliminary results for Saturn.
DE: 2704 Auroral phenomena (2407)
DE: 2721 Field-aligned currents and current systems (2409)
DE: 2736 Magnetosphere/ionosphere interactions (2431)
DE: 5737 Magnetospheres (2756)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting