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