SPRG Seminars - Archive

October 11, 2005:

Sources and Losses of Relativistic Electrons in the Van Allen Radiation Belts
Dr. Yuri Shprits, UCLA/Department of Atmospheric and Oceanic Sciences

The Earth radiation belts consist of energetic electrons and ions trapped by the magnetic field of the Earth. The electron radiation belts, which are the subject of this study, exhibit a two zone structure. The inner radiation belt is typically located between 1.2 and 2.0 Earth radii while the outer belt extends from 3.5 to 8 Earth radii. Variability of the high energy electron fluxes in the radiation belt is a result of the competition of the source and loss processes. Understanding loss and source mechanisms and their variability is important since high energy electrons create a hazardous environment for Earth orbiting satellites and humans in space. The relative contributions of various acceleration and loss mechanisms is the subject of the current study. Radial diffusion simulations and pitch-angle and energy diffusion simulations are compared to the measurements by CRRES, Akebono, SAMPEX, HEO and Polar satellites. We also present simulations and physical explanation of the unusual behavior of the radiations belts during the Halloween solar superstorms

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