SCHUMANN RESONANCE FREQUENCIES AND THE CONDUCTIVITY PROFILS IN THE ATMOSPHERE

Abstract

An automatic tracker of Schumann resonances was made and the vertical electric component was measured with a ball antenna. Average peak frequencies of each month from October 1971 to April 1972 were obtained. Overall average frequencies are 7.65, 14.12 and 20.35 Hz for the first three modes respectively. These frequencies agree very well with the previous observations in 1967-1968. On the other hand resonance frequencies from multi-signal sources are calculated with the atmospheric and lower ionospheric conductivity profiles from 10 to 140 km. Relatively good agreement between the experimental and theoretical resonance frequencies is obtained showing that the present conductivity profiles based on the balloon and rocket observations in mid-latitudes are better approximations of the world-wide average conductivity models for Schumann resonances than those in previous works.