HR: 0800h
AN: SH51B-1217    [Abstracts]
TI: Correlation Between Electron Counts at 500 eV and Magnetic Fields Downstream of the Bow Shock
AU: * Matsui, H
EM: hiroshi.matsui@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Torbert, R B
EM: Roy.Torbert@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Baumjohann, W
EM: baumjohann@oeaw.ac.at
AF: Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, Graz, 8042 Austria
AU: Kucharek, H
EM: harald.kucharek@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Mouikis, C G
EM: chris.mouikis@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Kistler, L M
EM: lynn.kistler@unh.edu
AF: Space Science Center, University of New Hampshire, Morse Hall, Durham, NH 03824 United States
AU: Balogh, A
EM: a.balogh@ic.ac.uk
AF: Blackett Laboratory, Imperial College, Prince Consort Road, London, SW7 2BW United Kingdom
AU: Paschmann, G
EM: goetz.paschmann@mpe.mpg.de
AF: Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, Garching, 85741 Germany
AB: It is known that the plasma parameters are often highly modulated downstream of the quasi-perpendicular bow shock. We have found oscillations of electron counts at 500 eV and magnetic fields with periods of ~ 1-3 s, i.e., below the proton cyclotron frequency, in Cluster data. The electron counts are measured by the electron drift instrument (EDI) during its ambient mode with a sampling frequency of 16 Hz, while the magnetic fields are measured by the fluxgate magnetometer (FGM) with a sampling frequency of 22.4 Hz. The correlation of the electron counts between three pitch angle ranges (~ 10, ~ 90, and ~ 170 degrees) are in-phase for all events. The correlation between the electron counts and the magnitude of the magnetic fields is sometimes anti-phase but in-phase at other times. The magnetic variation is left-handed or right-handed polarized accompanied by field-aligned components. It is possible to determine the mode of these waves by referring to plasma parameters from the Cluster ion spectrometry (CIS) instrument. Then we explore the reasons for the correlations between waves and particles by comparing with the results from linear theory and simulations. Finally upstream conditions are discussed in order to identify the sources of the waves.
DE: 2154 Planetary bow shocks
DE: 2728 Magnetosheath
DE: 7851 Shock waves (4455)
DE: 7867 Wave/particle interactions (2483, 6984)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: Fall Meeting 2005