ELECTROMAGNETIC FLUCTUATIONS MEASURED ON BOARD CLUSTER SATELLITES

A.Roux, O.Le Contel, S.Perraut, P.Robert, and N.Cornilleau CETP/UVSQ,Velizy,

G. Gustafsson, M. Andre, A. I. Eriksson, and, J.E.Wahlund, IRFU, Uppsala.

Preliminary analysis of electric and magnetic fluctuations, measured on Cluster satellites, in the plasma sheet is presented. Evidence is given for two types of fluctuations : 1-relatively structured fluctuations with a power spectrum peaking around a few Hz, presumably near the local lower hybrid frequency. 2-electromagnetic fluctuations, that develop as intense (dB/B>0.1) bursts, associated with changes in the magnetic field direction. We estimate the E/B ratio and characterise these electromagnetic bursts. We study the relation between these bursts, and the transport of the plasma.