Propagation and generation of low-frequency electromagnetic waves in the upper atmosphere

TLDR: In this article, the authors present a theory of propagation of low-frequency radio waves generated by very low frequency (VLF) emissions and a classification of observed VLF noise.

Abstract: CONTENTS Introduction 743 1 Observational Data on Natural Low-Frequency Radio Emission 744 a) Whistlers 745 Dispersion Long and short whistlers Multiple whistlers Nose whistlers Discharges that generate whistlers Experimental data on the trajectories of whistlers Systematic variations of properties of whistlers Observation of whistlers in the IGY program b) Very Low Frequency Emissions 749 Systematic classification of observed VLF noise Certain features of discrete radiation Method of propagation Tendency to form horizontal or gliding tones Connection with magnetic activity Comparison of steady states (hissing) with transients (discrete radiation) 2 Theory of Propagation of Low-Frequency Radio Waves Generation of VLF Emissions 751 Principal initial relations Group velocity and determination of trajectories Allowance for ion motion Interaction of normal waves Absorption Mechanisms of generation of VLF emissions 3 Low Frequency Radio Waves and Investigation of the Upper Atmosphere 761 Conclusion 763 Cited Literature 763