HR: 14:30h
AN: SM23D-03    [Abstracts]
TI: Role of Small-Scale Variations of the Electromagnetic Fields in the Evolution of Energetic Particle Populations in the Near-Earth's Magnetosphere
AU: * Ganushkina, N Y
EM: Nataly.Ganushkina@fmi.fi
AF: Finnish Meteorological Institute, Space Research, POBox 503, Helsinki, FIN-00101, Finland
AU: Kubyshkina, M V
EM: kubysh@geo.phys.spbu.ru
AF: Institute of Physics, University of St.-Petersburg, Ulyanovskaya,1, St.Petersburg, 198504, Russian Federation
AU: Pulkkinen, T I
EM: Tuija.Pulkkinen@fmi.fi
AF: Finnish Meteorological Institute, Space Research, POBox 503, Helsinki, FIN-00101, Finland
AB: Understanding the time-varying electromagnetic field configuration and the consequent charged particle dynamics in the Earth's space environment is fundamentally important both for scientific and space weather purposes. We have developed a time-evolving model for the inner magnetosphere magnetic field. Based on available in-situ observations of the magnetospheric magnetic field, the model gives a global representation of the magnetic field evolution during specified time periods. The main advantage of this event-oriented model is its ability to reproduce both the larger-scale and smaller-scale variations of the magnetic field during substorms and storms. We have incorporated this model into our particle tracing procedure, in which we trace particles with arbitrary pitch angles numerically in the drift approximation. From the other hand, we represent substorm-associated electromagnetic fields by adding electromagnetic pulses. There electric field is given by Gaussian pulse with azimuthal field component propagating inward with a velocity dependent on radial distance. The magnetic field from this pulse is calculated by Faraday's law. We model particle inward motion and energization by a series of electric field pulses representing substorm activations during storm events. We model two storms on October 21-23, 2001 and April 18, 2002, with characteristic saw-tooth activations observed in particle fluxes at geostationary orbit and magnetic field variations. We study the role of small-scale variations of the electromagnetic field in the evolution of energetic particle populations in the near-Earth's magnetosphere.
DE: 2712 Electric fields (2411)
DE: 2730 Magnetosphere: inner
DE: 2740 Magnetospheric configuration and dynamics
DE: 2778 Ring current
DE: 2788 Magnetic storms and substorms (7954)
SC: SPA-Magnetospheric Physics [SM]
MN: 2007 Joint Assembly