On whistler mode wave scattering from density irregularities in the upper ionosphere

This work concerns the problem of a whistler mode wave exit to the ground. After propagation in the magnetosphere a wave, in general, falls on the ionosphere with the angle of incidence outside the transmission cone. Such waves do not reach the Earth experiencing total internal reflection at the atmosphere-ionosphere boundary. To explain wave exit to the ground, we follow up on the idea of wave scattering on small-scale irregularities in the ionosphere. Interaction with these irregularities excites harmonics inside the transmission cone. Using the Green function method, we derive an integral equation for the wavefield containing all modes possible for a given frequency, solve this equation in the Born approximation, and obtain an expression for the energy flux of the waves which were scattered into the transmission cone.