HR: 0800h
AN: SM11A-0328    [Abstracts]
TI: Multispacecraft observations of chorus dispersion and source location
AU: * Breneman, A W
EM: awbrenem@hotmail.com
AF: University of Iowa, 201 Van Allen Hall, Iowa City, IA 52242, United States
AU: Kletzing, C
EM: craig-kletzing@uiowa.edu
AF: University of Iowa, 201 Van Allen Hall, Iowa City, IA 52242, United States
AU: Chum, J
EM: jaroslav-chum@uiowa.edu
AF: Academy of Sciences of the Czech Republic, Institute of Atmospheric Physics, Prague, 199 99, Czech Republic
AU: Gurnett, D
EM: donald-gurnett@uiowa.edu
AF: University of Iowa, 201 Van Allen Hall, Iowa City, IA 52242, United States
AU: Pickett, J
EM: jolene-pickett@uiowa.edu
AF: University of Iowa, 201 Van Allen Hall, Iowa City, IA 52242, United States
AU: Santolik, O
EM: ondrej-santolik@uiowa.edu
AF: Charles University, Department of Mathematics and Physics Praha 1 116 36, Prague, 199 99, Czech Republic
AB: Measurements from the Polar spacecraft have put an upper limit of a few thousand kilometers to the size of the magnetospheric chorus generation region along the magnetic field line in agreement with earlier theoretical estimates. Multipoint observations from the four Cluster spacecraft reveal that a single chorus wave packet can appear differently between spacecraft. One spacecraft observes a chorus element which is frequency shifted and time delayed relative to another. Since the dispersion relation for chorus waves is known, these differences provide a new opportunity to refine the parallel dimension of these source regions. A cross-correlation analysis is used to identify common chorus events between the Cluster spacecraft and to quantify their timing delays. The timing arrival differences and frequency accessibility are then simulated with a ray-tracing technique. Locations in the magnetosphere where the simulated frequency shift and time delay match the observed frequency shift and time delay for a single chorus event are determined as possible source regions. The identified source locations for multiple chorus events are presented as is a preliminary statistical survey of source emission characteristics of these regions.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2730 Magnetosphere: inner
DE: 2772 Plasma waves and instabilities (2471)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Fall Meeting