A New Population of Ultra?Relativistic Electrons in the Outer Radiation Zone

Van Allen Probes measurements revealed the presence of most unusual structures in ultra-relativistic radiation belts. Detailed modeling, analysis pitch angle distributions, difference between relativistic and ultra-realistic electron evolution, along with theoretical studies scattering wave growth, all indicate that electromagnetic ion cyclotron (EMIC) waves can produce a very efficient loss electrons heart Moreover, detailed profiles phase space densities provides direct evidence for localized by EMIC waves. The evolution multi-MeV fluxes shows dramatic sudden enhancements selected storms. Analysis density reveals growing peaks at different values first invariant are formed approximately same radial distance from Earth show sequential formation lower to higher energies, indicating local energy diffusion is dominant source acceleration MeV energies. Further simultaneous background energies only occurs when plasma significantly depleted outside plasmasphere, which consistent modeling due chorus