Field‐aligned instability due to stimulated scattering of intense radio waves from diffusion quasi‐modes

Abstract

A field‐aligned instability is found when intense radio waves undergo stimulated scattering off low frequency quasi‐modes related to parallel diffusion. This instability may arise during ionospheric modification. The wavelength of the unstable field‐aligned diffusion mode is between 75 and 200 m, in agreement with the experimental findings of Bowhill [1974]. The growth time is at least a second, and the instability should extend over an altitude range on the order of 100 km.