HR: 15:10h
AN: SM33B-07 [Abstracts]
TI: The Role Of Non-Adiabatic Processes In The Creation Of The Outer Radiation Belts
AU: * Fox, N J
EM: nicola.fox@jhuapl.edu
AF: Johns Hopkins University/ Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Mauk, B M
EM: barry.mauk@jhuapl.edu
AF: Johns Hopkins University/ Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723
United States
AU: Blake, J B
EM: JBernard.Blake@aero.org
AF: The Aerospace Corporation, P.O. Box 92957, Los Angeles, CA 90009
United States
AB:
The dynamic variation of the electrons in the outer radiation belts has been observed for many years, but the cause of this
variation has not been clearly understood. The adiabatic effect due to ring current evolution is not sufficient to account
for flux changes during storm phases. Thus, addition processes have been invoked to explain these variations, chiefly the
radial diffusion of electrons conserving the first and second adiabatic invariants, where the electrons are accelerated
through the betatron and fermi processes, and perhaps with enhanced transport enabled by ULF waves. More recently, local
heating inside the radiation belts has been proposed to explain the energization of electrons. However, the exact mechanism
that produces the lower energy seed population and converts them to energetic radiation belt electrons has not yet been
clarified.
In this presentation we will examine the current understanding of the processes which accelerate electrons into the radiation
belts with particular emphasis on the role of non-adiabatic processes. The energies that electrons can acquire via radial
diffusion are determined using data from ISEE and CRRES, and samples of spectra are examined at various L-values to identify
the deficiencies in phase space density. This will determine the extent to which non-adiabatic processes are required to
achieve the observed radiation belt energies. We have found strong evidence supporting recent suggestions that non-adiabatic
(first invariant breaking) processes are required to explain the generation of the outer belt during intense storm events. We
will report on the relative importance of non-adiabatic processes during more typical outer belt conditions.
DE: 2700 MAGNETOSPHERIC PHYSICS
DE: 2716 Energetic particles, precipitating
DE: 2730 Magnetosphere--inner
DE: 2740 Magnetospheric configuration and dynamics
DE: 2760 Plasma convection
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting