HR: 08:50h
AN: SM21B-04 INVITED     [Abstracts]
TI: Tests of substorm scenarios, based on multipoint measurements.
AU: * Roux, A F
EM: alain.roux@cetp.ipsl.fr
AF: CETP_UVSQ, 10-12 avenue de l'Europe, Velizy, 78140 France
AU: Le Contel, O
EM: olivier.lecontel@cetp.ipsl.fr
AF: CETP_UVSQ, 10-12 avenue de l'Europe, Velizy, 78140 France
AU: Fontaine, D
EM: dominique.fontaine@cetp.ipsl.fr
AF: CETP_UVSQ, 10-12 avenue de l'Europe, Velizy, 78140 France
AU: Robert, P
EM: patrick.robert@cetp.ipsl.fr
AF: CETP_UVSQ, 10-12 avenue de l'Europe, Velizy, 78140 France
AU: Holter, O
EM: oivin.holter@cetp.ipsl.fr
AF: CETP_UVSQ, 10-12 avenue de l'Europe, Velizy, 78140 France
AU: Louarn, P
EM: philippe.louarn@cesr.fr
AF: CESR, 38 avenue du Colonel Roche, Toulouse, 31028 France
AU: Sauvaud, J
EM: jean-andre.sauvaud@cesr.fr
AF: CESR, 38 avenue du Colonel Roche, Toulouse, 31028 France
AU: Fazakerley, A
EM: anf@mssl.ucl.ac.uk
AF: MSSL-University College London, Holmbury St. Mary, Dorking, RH5 6NT United Kingdom
AU: Owen, C
EM: cjo@mssl.ucl.ac.uk
AF: MSSL-University College London, Holmbury St. Mary, Dorking, RH5 6NT United Kingdom
AB: There are essentially two types of models for substorms: - Substorms are triggered by the spontaneous development of one (or several)X-line(s), in the mid-tail (20-30 Re), which leads to fast flows. Earthward of the reconnection site (X-line) flow bursts are directed earthward. While approaching the dipolar region the speed of these flows is reduced (flow braking), which can result in a dipolarization. Substorms are triggered by current disruption via an instability, which produces the observed dipolarization. The dipolarization starts in the NEPS, and propagates radially outward, thereby causing the reduction of the tail current. In this type of model the formation of X-line is the consequence of the dipolarization. Both models have several common features, but in a different order. In an attempt to establish the sequence of these events we use Cluster multipoint observations (hopefully combined with DSP), to determine the direction of propagation of the perturbation associated with early substorm development. As a second criterion we investigate the spatial distribution of the currents, which is expected to be different in the two models.
DE: 2748 Magnetotail boundary layers
DE: 2788 Storms and substorms
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting