HR: 16:35h
AN: SM24A-02    [Abstracts]
TI: Overview of Plasmaspheric Plumes With WHISPER/CLUSTER Observations
AU: * Darrouzet, F
EM: Fabien.Darrouzet@oma.be
AF: Belgian Institute for Space Aeronomy (IASB-BIRA), Avenue Circulaire, 3, Brussels, 1180, Belgium
AU: De Keyser, J
EM: Johan.DeKeyser@oma.be
AF: Belgian Institute for Space Aeronomy (IASB-BIRA), Avenue Circulaire, 3, Brussels, 1180, Belgium
AU: Décréau, P M
EM: Pierrette.Decreau@cnrs-orleans.fr
AF: Laboratoire de Physique et Chimie de l'Environnement (LPCE), 3A, Avenue de la Recherche Scientifique, Orléans, 45071, France
AU: El Lemdani-Mazouz, F
EM: mazouz@cnrs-orleans.fr
AF: Laboratoire de Physique et Chimie de l'Environnement (LPCE), 3A, Avenue de la Recherche Scientifique, Orléans, 45071, France
AU: Vallières, X
EM: Xavier.Vallieres@cnrs-orleans.fr
AF: Laboratoire de Physique et Chimie de l'Environnement (LPCE), 3A, Avenue de la Recherche Scientifique, Orléans, 45071, France
AB: Plasmaspheric plumes have been routinely observed by CLUSTER. They are a common feature of the plasmasphere geometry and exhibit the high dynamics of this region. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles are derived from the plasma frequency identified by the WHISPER instrument onboard CLUSTER. Plasmaspheric plumes are identified from density profiles determined along plasmasphere crossings as a significant density increase followed by a density decrease from the background value. Note that the WHISPER instrument has a limited frequency range (2-80 kHz); therefore only plasmaspheric plumes with densities below 80 cm^-3 are listed in this study. Another limitation comes from the relatively high perigee of CLUSTER (4 R_E), which means that the satellites cross the outer regions of the plasmasphere, which happen to be the most dynamic ones. We present a statistical analysis of plasmaspheric plumes observed by WHISPER onboard the four CLUSTER spacecraft during 5 years (1 February 2001 to 1 February 2006). Their occurrence is studied as a function of several geomagnetic indices (Kp, Dst and IMF); their transverse equatorial size, magnetic local time and magnetic latitude distribution is presented; comparisons of the density profiles of the same plume crossed in the Northern and Southern Hemisphere are also shown.
DE: 2730 Magnetosphere: inner
DE: 2740 Magnetospheric configuration and dynamics
DE: 2768 Plasmasphere
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly