Full-wave modeling of transionospheric propagation of VLF waves

The full-wave method (FWM) of N. G. Lehtinen and U. S. Inan (2008) is used to model trans-ionospheric propagation of VLF electromagnetic waves from ground-based transmitters up to satellite altitudes. Direct comparison with satellite observations indicates that the VLF wave intensities measured at satellite altitudes are substantially smaller than predicted. The apparent reduction in amplitude is attributed to the presence of irregularities in the ionosphere, which the waves encounter during their traversal of the lower ionosphere. Linear mode scattering from the irregularities convert the whistler waves into quasi-electrostatic whistler mode (QEWM) waves with wave normal angles near the resonance cone. Recent enhancements to the FWM are also described, which allow the minimization of an aliasing error encountered in taking the inverse Fourier transform. Citation: Lehtinen, N. G., and U. S. Inan (2009), Full-wave modeling of transionospheric propagation of VLF waves, Geophys. Res. Lett., 36, L03104, doi: 10.1029/2008GL036535.