HR: 0800h
AN: SM41A-1114    [Abstracts]
TI: Radial Diffusion Coefficients for the Transport of Radiation-Belt Particles: a Case Study for Protons and Electrons in Jupiter's Inner Magnetosphere
AU: * Santos-Costa, D
EM: Daniel.Santos-Costa@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Bolton, S J
EM: Scott.J.Bolton@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Garrett, H B
EM: Henry.B.Garrett@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AU: Krupp, N
EM: krupp@linmpi.mpg.de
AF: MPIfA, Max-Planck-Str. 2, Katlenburg-Lindau, D-37191 Germany
AU: Sault, R
EM: rsault@atnf.csiro.au
AF: ATNF Paul Wild Observatory, Locked Bag 194, Narrabri, NSW 2390 Australia
AU: Thorne, R M
EM: rmt@atmos.ucla.edu
AF: Department of Atmospheric Sciences, UCLA, Los Angeles, CA 90095 United States
AU: Levin, S
EM: steven.levin@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 United States
AB: We propose to discuss the general expression for the radial diffusion coefficients of energetic charged particles transported in magnetospheric systems. Since the late 60's and based on the postulate that diffusion only violates the particle's third adiabatic invariant, radial diffusion coefficients inside inner magnetospheres of the outer planets have been assumed to be driven by neutral winds in the ionosphere implying that $D_{LL} = D_{o}*L^{n}$ in parametric form. $D_{o}$ and n are free parameters usually constrained by observations. We will discuss the parameters n and Do, and the L dependence of such coefficients by reexamining a more rigorous expression of the radial diffusion coefficients. In a dipolar approximation, the expression for these coefficients is simple making it easier is to bring out their dependence as a function of the type of particle, energy, pitch-angle and radial distance. Consequently, the limits of validity of the general parametric form can be discussed. The radial diffusion coefficients used in the governing Fokker-Planck transport equation allow determination of the averaged radiation-belt particle populations by providing a balance between sources and losses. We then illustrate the consequences of the different expressions of the transport coefficients on the radiation belts of Jupiter. Furthermore, given the assumed origin of the particles' transport, the effects of the radial diffusion (including the solar-wind dynamic pressure, and the consequences of its fluctuations) can also be studied on the steady state radiation belts and implications for the long-term variations observed in Jupiter's synchrotron emissions evaluated.
DE: 9800 GENERAL OR MISCELLANEOUS
DE: 2700 MAGNETOSPHERIC PHYSICS
DE: 2799 General or miscellaneous
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting