MODELING OF UPSTREAM ENERGETIC PARTICLE EVENTS OBSERVED BY WIND

Energetic particle events observed upstream of the bow shock can have two possible sources, shock acceleration of solar wind particles or le akage from the magnetosphere. Three-dimensioned global fluid simulatio ns in conjunction with particle tracking in global fields are used to investigate the sources of the energetic particles. Acceleration of pa rticles from the bow shock can account for many of the lower intensity events but the magnetosphere appears to be an important source during the more energetic particle events where 2 MeV particles are observed .