This proposal is to investigate energetic particle injections (electrons 50keV,ions 100 keV) associated with geomagnetic storms and substorms in an attempt to understand the change of the magnetic and electric fields in the tail and inner magnetosphere during these events. Investigations will focus upon impulsive injections associated with isolated substorms and the resulting drift echoes observed in the inner magnetosphere. Drift echoes can provide information about changes in the magnetic and electric fields in both time and space, which can be utilized in models of the fields that govern the particle motions. Test particle tracing techniques will be utilized and the simulation results will be compared with observations.
