Evidence of Whistler Guidance by Magneto-ionic Ducts of Poorly-defined Structure

Abstract

THE highly localized character of multiple whistler signals suggests strongly (though indirectly) that columns of field aligned ionization must exist^1–4. In addition, simple ray tracing calculations show quite clearly that without these hypothetical columns a rapid dispersion in latitude would be observed following successive reflexions at conjugate magnetic field regions⁵. There is some direct experimental evidence⁶ for the existence of these columns; but by and large, only column fragments seem to have been observed. Indeed, recent top-side probe measurements show no evidence for continuous columns⁷.