Ground Transmitter Waves in the Magnetosphere and Their Role in Electron Scattering

Very low frequency (VLF) ground transmitters emit signals for communication purposes via the Earth-ionosphere waveguide. Part of their energy propagates upward into the magnetosphere via whistler-mode waves and interacts with energetic electrons there. Quantifying this effect requires a global transmitter-wave model in the magnetosphere. Here, we present a model based on tracing millions of ray paths from the topside ionosphere, with source emission specified by DEMETER observations. Our simulation results demonstrate that the nonducted wave propagation results are consistent with the observed distribution of both wave intensity and wave normal. Pitch angle scattering rates are derived using the modeled wave distribution, demonstrating NWC transmitter enables a range of electron loss time scales from as short as a day to 100 days, depending on electron energy.