The investigators will combine magnetohydrodynamic (MHD) modeling with test particle simulations to study adiabatic transport and energization in the radiation belts. The MHD model provides the global configuration of the magnetosphere in response to solar wind forcing, while the test particle code tracks the motion of energetic particles within the ambient electric and magnetic fields. The computer simulations will be used to examine the stormtime evolution of energetic particles in the near-Earth plasma sheet and radiation belts, and, through comparison with observations, the adiabatic transport and acceleration of a plasma sheet source population. The models will be run for actual geomagnetic storm events and the results compared with available observations. The investigators will study plasma sheet particle acceleration and trapping to quantify the importance of plasma sheet particles in radiation belt dynamics. Energetic particles in the radiation belts represent a threat to satellites, so it is important to understand the various factors that influence radiation flux levels in near-Earth space.
