HR: 0830h
AN: SM21B-0206    [PDF]
TI: Low Frequency Perturbations in the Plasmasheet: Resonant Absorption and Comparison with CLUSTER
AU: * Fruit, G
AF: CESR/CNRS, 9, AV. du Colonel ROCHE, TOULOUSE, 31028 France
AU: Louarn, P
EM: philippe.louarn@cesr.fr
AF: CESR/CNRS, 9, AV. du Colonel ROCHE, TOULOUSE, 31028 France
AU: Genot, V
AF: CESR/CNRS, 9, AV. du Colonel ROCHE, TOULOUSE, 31028 France
AU: BUDNIK, E
AF: CESR/CNRS, 9, AV. du Colonel ROCHE, TOULOUSE, 31028 France
AU: Sauvaud, J
AF: CESR/CNRS, 9, AV. du Colonel ROCHE, TOULOUSE, 31028 France
AU: Lucek, E
AF: The Blackett Laboratory, Imperial College, LONDON, SW7 2BZ United Kingdom
AU: Balogh, A
AF: The Blackett Laboratory, Imperial College, LONDON, SW7 2BZ United Kingdom
AB: We present an analysis of the propagation of compressive MHD perturbations in a plasmasheet (described as being an Harris-type sheet). We explicitly solve the linear response of the plasmasheet to an initial perturbation by using the Green formalism. Emphasis is made on the continuous eigenmodes of the system linked to the resonant absorption process. Through this phenomenon some energy may be tranferred from the waves to the plasma. Using a quasi-analytical model, we (1) precisely quantify the amount of energy that these MHD waves can deposit in the sheet and (2) evaluate the time and space scales of this transfer. These results are then compared with CLUSTER observations. Using a technique of reconstruction of the signal from actually observed fluctuations, we estimate the amplitude of the continuous modes and we precise the role of the resonant absorption mechanism in the energization of the plasmasheet. This can be considered as a first step for an observational quantization of the possible role of this mechanism in natural plasmas.
DE: 2752 MHD waves and instabilities
DE: 2764 Plasma sheet
SC: SPA - Magnetospheric Physics [SM]
MN: 2003 Fall Meeting