HR: 14:35h
AN: SM33E-04    [Abstracts]
TI: Magnetic field fluctuations in the cusp studied with CLUSTER data : evidence of intermittency
AU: Echim, M
EM: marius.echim@oma.be
AF: IASB-BIRA, Avenue Circulaire 3, BRUSSELS, 1180 Belgium
AU: * LAMY, H
EM: herve.lamy@oma.be
AF: IASB-BIRA, Avenue Circulaire 3, BRUSSELS, 1180 Belgium
AU: Darrouzet, F
EM: fabien.darrouzet@oma.be
AF: IASB-BIRA, Avenue Circulaire 3, BRUSSELS, 1180 Belgium
AU: LEMAIRE, J
EM: lemaire@spaceradiations.be
AF: Center for Space Radiations, Rue du Cyclotron 2, Louvain-La-Neuve, 1348 Belgium
AU: Decreau, P
EM: pdecreau@cnrs-orleans.fr
AF: LPCE/CNRS, Orleans University, 3A Avenue de la recherche scientifique, Orleans, 45071 France
AU: Dunlop, M
EM: M.Dunlop@rl.ac.uk
AF: Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX United Kingdom
AB: During the outbound pass of February 26, 2001, the magnetic field data measured by the four CLUSTER satellites are used to investigate the turbulent characteristics of the plasma flow in the cusp. We compute the probability distribution functions (PDF) and the flatness parameter of the magnetic field fluctuations at various scales τ. At lower altitudes, in the inner magnetosphere, PDFs are approximate Gaussian and the flatness ℱ is close to 3. On the other hand, at higher altitudes in the outer cusp, PDFs of magnetic fluctuations have non-Gaussian shapes with higher probabilities to have large fluctuations at smaller scales. The flatness also increases strongly (ℱ >> 5) for small scales (τ < 4 sec) indicating the presence of intermittent turbulence. We also show that the magnetic fluctuations display a multifractal behavior. Finally, the correlation coefficients (auto and cross) are computed for each magnetic component and each satellite in order to evaluate the size of the coherent structures interacting in this turbulent region.
DE: 2706 Cusp
DE: 2724 Magnetopause and boundary layers
DE: 4440 Fractals and multifractals
DE: 4475 Scaling: spatial and temporal (1872, 3270, 4277)
DE: 4490 Turbulence (3379, 4568, 7863)
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005