HR: 13:40h
AN: SM22C-01    [PDF]
TI: The role of Alfv\'enic turbulence in Jupiter's M-I coupling
AU: * Saur, J
EM: Joachim.Saur@jhuapl.edu
AF: Johns Hopkins University, APL, 11100 Johns Hopkins Rd, Laurel, MD 20723 United States
AU: Pouquet, A
EM: pouquet@ucar.edu
AF: NCAR, P.O. Box 3000, Boulder, CO 80307 United States
AU: Matthaeus, W H
EM: yswhm@bartol.udel.edu
AF: Bartol, Research Institute, 217 Sharp Lab, Newark, DE 19716 United States
AB: In our presentation we will discuss the role of Alfv\'en waves in Jupiter's M-I coupling and their connection to Jupiter's powerful auroral oval, with an emitted UV power about three orders of magnitude larger than Earth's aurora. We will relate the mechanisms in Jupiter's magnetosphere to understanding developed in the Earth context. One of the main differences between Jupiter's and the Earth's magnetosphere is the quasi steady source of Alfv\'en waves deep inside Jupiter's magnetosphere triggered by radial plasma transport. These Alfv\'enic fluctuations propagate along the closed field lines in Jupiter's middle magnetosphere and counter propagating waves interact non-linearly to create a turbulent cascade of small scale Alv\'enic fluctuations. When the scales of the fluctuations reach kinetic scales, the fluctuations are dissipated at high magnetic latitudes. At the presence of a net field-aligned electric current also due to radial mass transport, the dissipation process accelerates electrons to produce Jupiter's main auroral oval. We will discuss these mechanisms in detail. We will also present Galileo spacecraft measurement of the Poynting flux and spectral energy fluxes associated with the Alfv\'enic fluctuations and compare them with recent Hubble Space Telescope (HST) Observations of Jupiter's main auroral oval. We show that the voltage -- energy flux relationship inferred from latest HST observations (private communication J.-C. G\'erard) fit well with our theoretical model predictions.
DE: 2704 Auroral phenomena (2407)
DE: 2736 Magnetosphere/ionosphere interactions
DE: 2756 Planetary magnetospheres (5443, 5737, 6030)
DE: 6220 Jupiter
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting