DIURNAL VARIATIONS OF RESONANT FREQUENCIES IN THE EARTH-IONOSPHERE CAVITY

Abstract

Diurnal variations of resonant peak frequencies in the earth-ionosphere cavity were obtained for the first three modes of the electric vertical and horizontal NS and EW components through a year from February, 1967 to January, 1968. The result shows a different variation pattern for each component. There are frequency decreases in the morning and in the evening for the vertical and NS components. It would be preferable for the EW component to show that frequency increases exist at around corresponding times in the morning and in the evening. Diurnal amplitude ranges from 0.1 to 0.8 Hz.