Observations and Fokker-Planck Simulations of the L-Shell, Energy, and Pitch Angle Structure of Earth's Electron Radiation Belts During Quiet Times
Abstract
The evolution of the radiation belts in L-shell (L), energy (E), and equatorial pitch angle (alpha(0)) is analyzed during the calm 11-day interval (4-15 March) following the 1 March 2013 storm. Magnetic Electron and Ion Spectrometer (MagEIS) observations from Van Allen Probes are interpreted alongside 1D and 3D Fokker-Planck simulations combined with consistent event-driven scattering modeling from whistler mode hiss waves.
Three (L, E, alpha(0)) regions persist through 11 days of hiss wave scattering; the pitch angle-dependent inner belt core (L similar to similar to 5 and E similar to 100 keV, 3.5 < L < L-pp similar to 6. Thus, observed unidirectional flux decays can be used to estimate local pitch angle diffusion rates in that region.
Top-hat distributions are computed and observed at L similar to 3-3.5 and E = 100-300 keV.