On the Cross-Energy Cross-Pitch-Angle Coherence of Electrons in the Outer Radiation Belt

Abstract:

Relativistic electrons, mainly trapped in the Earth’s outer radiation belt, present a highly hazardous radiation environment for electronic hardware on board satellites and spacecraft. Thus developing a predictive capability for MeV electron levels as well as understanding the physics have been deemed critical for both space research and industry communities. In this work, we first demonstrate that a high cross-energy cross-pitch-angle coherence exists between the trapped ~MeV electrons and precipitating ~100s KeV electrons—observed respectively by Van Allen Probes and NOAA POES satellites in different orbits—by conducting a correlation survey on measurements from both high- and low-altitudes. Then, based upon the results, we further test the possibility of using a linear prediction filter model, driven by POES observations from low-Earth-orbits, to predict the energization of MeV electrons after geomagnetic storms, as well as the evolving distributions of MeV electrons in real time. Finally, to account for this high coherence, we provide our hypothesis based upon theoretical calculations and numerical simulations for individual events using diffusion codes with realistic particle and wave inputs from missions including Van Allen Probes. Results from this study unveil new knowledge on radiation belt dynamics, add new science significance to a long existing space infrastructure, and provide practical and useful tools to the whole space community.