HR: 1340h
AN: SM53A-1079 [Abstracts]
TI: Plasma Sheet Magnetic Field Fluctuations Characterized by Galileo at Jupiter
AU: * Luk, O
EM: oluk@uci.edu
AF: Inst. of Geophs. and Planetary Phys., 6843 Slichter Hall,
405 Hilgard Ave., Los Angeles, CA 90095-1567, United States
AU: * Luk, O
EM: oluk@uci.edu
AF: Now at: Physics Department, University Califoria, Irvine, Irvine, CA 92697-4575, United
States
AU: Weygand, J M
EM: jweygand@igpp.ucla.edu
AF: Inst. of Geophs. and Planetary Phys., 6843 Slichter Hall,
405 Hilgard Ave., Los Angeles, CA 90095-1567, United States
AU: Joy, S
EM: sjoy@igpp.ucla.edu
AF: Inst. of Geophs. and Planetary Phys., 6843 Slichter Hall,
405 Hilgard Ave., Los Angeles, CA 90095-1567, United States
AU: Kivelson, M G
EM: mkivelson@igpp.ucla.edu
AF: Inst. of Geophs. and Planetary Phys., 6843 Slichter Hall,
405 Hilgard Ave., Los Angeles, CA 90095-1567, United States
AB:
Spectral indices from power spectra of the magnetic field fluctuations observed within the Earth's plasma sheet
appear to confirm the presence of turbulence in the magnetotail. Using Galileo magnetometer data mainly from
Jupiter's magnetotail, we have determined spectral indices from power spectra within the frequency range of
tenths of mHz to 10 mHz for approximately 100 plasma sheet intervals over a range of local times principally in
the noon to midnight sector and at radial distances between 20 and 60 RJ. We find spectral indices centered
near -2.3 for the radial and azimuthal components of the field, but typically closer to -2.0 for the north-south
component. The most probable values do not appear to depend strongly on local time but local time coverage is
spotty. When examined as a function of the radial distance, the spectral index decreases with radial distance from
values near -1.4 to 2.0 in the range 20-30 RJ to values near -2.3 to -2.6 in the range 50-60 RJ.. The observed
spectral indices are not those expected for homogenous fully developed turbulence (-5/3) or MHD turbulence (-
3/2). For some of our observations, the large negative indices may relate to fluctuations in the dissipative regime.
We will discuss our observations in the context of the spectral indices and other derived values.
DE: 2744 Magnetotail
DE: 2756 Planetary magnetospheres (5443, 5737, 6033)
DE: 5443 Magnetospheres (2756)
DE: 5737 Magnetospheres (2756)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting