HR: 1340h
AN: SM23A-1197    [Abstracts]
TI: Correlative scale and effective magnetic Reynolds number determination from plasma sheet and solar wind magnetic field fluctuations
AU: * Weygand, J M
EM: jweygand@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 405 Hilgard Ave, Los angeles, CA 90095-1567, United States
AU: Kivelson, M G
EM: mkivelson@igpp.ucla.edu
AF: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, 405 Hilgard Ave, Los angeles, CA 90095-1567, United States
AU: Matthaeus, W H
EM: whm@udel.edu
AF: Department of Physics and Astronomy, University of Delaware, 217 Sharp Laboratory, Newark, DE 19711, United States
AU: Dasso, S
EM: dasso@df.uba.ar
AF: Instituto de Astronomía y Física del Espacio (IAFE), CC 67 Suc. 28, Buenos Aires, 1428, Argentina
AU: Kistler, L M
EM: kistler@atlas.sr.unh.edu
AF: Experimental Space Plasma Group, University of New Hampshire, 131 Main Street, Durham, NH 03824, United States
AB: Cluster data from many different intervals in the magnetospheric plasma sheet are employed to determine the magnetic correlative scale and the Taylor microscale from simultaneous multiple point measurements. For this study we define the correlative scale as the exponential decay constant of the correlation coefficient as a function of spacecraft separation and the Taylor scale as the radius of curvature of the correlation coefficient values at zero separation. The present determination of the Taylor scale makes use of a novel extrapolation technique to derive a statistically stable estimate from a range of measurements at small spatial separations. In the plasma sheet the correlative scale length is found to be largest (about 20,000 km) in the direction parallel to the magnetic field and smallest (about 10,000 km) in the direction perpendicular to the magnetic field. Similar results have been determined in the slow solar wind using Cluster and several other spacecraft. The effective magnetic Reynolds number can be expressed in terms of the correlative scale and the Taylor scale. Knowledge of the effective magnetic Reynolds number may be useful in magnetohydrodynamic modeling of the magnetosphere and the solar wind and may provide constraints on kinetic theories of dissipation in space plasmas.
UR: http://www.igpp.ucla.edu/jweygand
DE: 2149 MHD waves and turbulence (2752, 6050, 7836)
DE: 2164 Solar wind plasma
DE: 2744 Magnetotail
DE: 2764 Plasma sheet
DE: 4490 Turbulence (3379, 4568, 7863)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting