HR: 1330h
AN: SM43C-03    [Abstracts]
TI: Cluster/Rapid Electron Pitch Angle Transitions During a Storm Time Substorm Event on October 07, 2002 in the Context of Global Multi-Spacecraft Observations
AU: * Vogiatzis, I I
EM: ivogiatz@ee.duth.gr
AF: Center for Space Physics, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 United States
AU: * Vogiatzis, I I
EM: ivogiatz@ee.duth.gr
AF: Space Physics Laboratory, Department of Electrical and Computer Engineering, Democritus University of Thrace, 12 Vas. Sofias, Xanthi, 67100 Greece
AU: Fritz, T A
EM: fritz@bu.edu
AF: Center for Space Physics, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 United States
AU: Zong, Q G
EM: zong@bu.edu
AF: Center for Space Physics, Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 United States
AU: Sarris, E T
EM: sarris@ee.duth.gr
AF: Space Physics Laboratory, Department of Electrical and Computer Engineering, Democritus University of Thrace, 12 Vas. Sofias, Xanthi, 67100 Greece
AB: Electrons traveling along and perpendicular to magnetic field lines have been observed in the magnetotail at L~17 and 22MLT during the recovery phase of a storm time substorm event on October 07, 2002. Our analysis is based on data obtained from geosynchronous and Cluster satellites. According to geosynchronous measurements an electron dispersionless injection is very well correlated with a dipolar re-configuration of the magnetic field something that has been previously observed in the case of the 27 August 2001 substorm for the case of protons. The later supports the idea that electrons and in general particle injections at geosynchronous altitude are directly related to electric fields that arise from field dipolarization/current disruption. By calculating the 90 degree electron spectrum at Cluster location we find that is shifted relatively to the bidirectional one. This could either mean a) that we have a net supply of 90 degree electrons from a remote location which are drifting perpendicular to the ambient magnetic field (vertical shift of the spectrum) b) that we have a local energization and most of the gained energy is transformed to perpendicular energy (betatron acceleration, horizontal shift of the spectrum) and c) that both mechanisms are active. However, by examining the relative ratios of the bi-directional and 90 degree electrons for the selected time intervals we observed that the two populations act independently with the bi-directional electrons preserving their count rate. The later supports the idea that the spectrum shifting is due to an electron transportation perpendicular to the magnetic field by means of gradient/curvature drift from a remote location while the bi-directional electrons are most likely related with a neutral line formation.
DE: 2720 Energetic particles, trapped
DE: 2731 Magnetosphere--outer
DE: 2740 Magnetospheric configuration and dynamics
DE: 2744 Magnetotail
SC: SPA-Magnetospheric Physics [SM]
MN: 2005 Joint Assembly