Dynamics of Energetic Electron Fluxes in the Inner Magnetosphere: SAMPEX

Dr. Dimitris Vassiliadis
Lab. for Extraterrestrial Physics
NASA Goddard Space Flight Center

The production of energetic electrons in a planetary magnetosphere is an important physical interaction and its understanding may be of practical significance. In Earth's magnetosphere, the acceleration of electrons to high energies and associated transport are correlated with the activity in the interplanetary medium, in particular the solar wind bulk velocity [Paulikas and Blake, 1979]. The most widely investigated current theoretical framework involves excitation of ULF waves whose lower modes resonantly accelerate seed populations of 100 keV to relativistic energies. Thus both major energy transfer mechanisms, reconnection and "viscous" interaction, participate in the energization process albeit at different stages. We identify relevant temporal and spatial scales of the interaction by revisiting the coupling between solar wind and electron fluxes using modern data sets (the SAMPEX/PET detector in the 2-6 MeV range) and filter methods. Systematic variations with season and solar cycle phase show a close coupling of the inner magnetosphere to the solar wind velocity, density, and IMF Bz component.