Acceleration of Radiation Belt Electrons: In Situ Heating vs. Inward Radial Transport

University Of Colorado At Boulder, Boulder CO

Investigators

Abstract

Electrons in Earth's radiation belts can have serious effects on spacecraft electronics through radiation damage and deep dielectric charging. The physical mechanisms governing the variability of these energetic electrons are still hot topics of debate. The paradigm for explaining the creation of the electron radiation belts has recently been shifting from one using only the theory of radial diffusion to one including an important role for plasma waves. The interaction of plasma waves with the electrons can result in in situ heating. This project will investigate the relative contribution of radial diffusion and in situ heating to the enhancement of MeV electrons inside geosynchronous orbit. An internal source term will be added to a currently existing radial diffusion model. Measurements of electrons using Los Alamos National Laboratory (LANL) satellite data at geosynchronous orbit will be used to determine the source population. Realistic loss rates will be determined from data taken from the SAMPEX satellite. The model results will then be compared to GPS satellite measurements inside geosynchronous orbit. In this way, it will be possible to determine how much enhancement of the MeV electrons measured by GPS can be attributed to inward radial transport and how much to in situ heating. This project will include research and training for graduate students. The results will enhance our ability to predict an important space weather phenomenon.