HR: 0800h
AN: SM21A-0307    [Abstracts]
TI: Cavity resonance triggered by inward movement of a plasmaspheric plume
AU: * Laakso, H
EM: Harri.Laakso@esa.int
AF: ESA/ESTEC, Postbuss 299, Noordwijk, 2200AG, Netherlands
AU: Escoubet, P
EM: Philippe.Escoubet@esa.int
AF: ESA/ESTEC, Postbuss 299, Noordwijk, 2200AG, Netherlands
AU: Taylor, M
EM: Matthew.Taylor@esa.int
AF: ESA/ESTEC, Postbuss 299, Noordwijk, 2200AG, Netherlands
AU: Aasnes, A
EM: Arne.Aasnes@esa.int
AF: ESA/ESTEC, Postbuss 299, Noordwijk, 2200AG, Netherlands
AU: Masson, A
EM: Arnaud.Masson@esa.int
AF: ESA/ESTEC, Postbuss 299, Noordwijk, 2200AG, Netherlands
AB: We investigate an event in the duskside inner magnetosphere where a sudden inward movement of a pre- existing plasmaspheric plume triggers a cavity resonance between the plume and the plasmapause. The event is recorded by five spacecraft (four Cluster and GOES 8) located in different positions in the cavity: one spacecraft within the plasmapause region and four in the cavity within L =4-6.6. All four spacecraft observe ULF wave mode at ~5 mHz at the same frequency and in the same phase even though the spacecraft are widely separated, indicating that the wave is a fundamental mode cavity resonance. The resonance is first left-hand polarized but changes into the right-hand polarized in the middle of the event at all locations. The event ends on each spacecraft when the spacecraft enters the plume. The plume movement is caused by a sudden change in geomagnetic activity, causing fast convection outside the plume that pushes the plume from L=8-10 to L=6-8.
DE: 2730 Magnetosphere: inner
DE: 2731 Magnetosphere: outer
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting