Effect of the ionosphere on the interaction between ULF waves and radiation belt electrons

The diffusion and energization of electrons in the equatorial plane of Earth's magnetosphere by ULF waves under different ionosphere boundary conditions are examined. Using test-particle simulations and considering intervals of weak geomagnetic activity, we find that the highest energization and minimum diffusion rates correspond to nightside ionosphere conditions. Conversely, the highest diffusion rates and minimum energization are seen for a perfectly reflecting ionosphere boundary. The maximum energies gained under dayside conditions, when Hall conductivity is included, are slightly greater than the maximum energy for similar conditions without Hall conductivity. The diffusion rates for dayside ionosphere conditions with only Pedersen conductivity are greater than the diffusion rates when Hall conductivity is included. These findings show that ULF wave-particle interactions in Earth's magnetosphere depend on the ionosphere conductance.