Memoirs of the Kakioka Magnetic Observatory Vol.13 No.01， p.1, September, 1968
Burst-like Occurrence of the Schumann Resonance
Yanagihara, K.
Abstract
Sonogram of Schumann resonance shows a characteristic fine structure. The pattern of resonance line on sonogram is made of discrete spots. Each spot represents burst-like occurrence of oscillation. The peak frequency expressed by the ordinate of spot on sonogram fluctuates over the range of about 4 Hz. Theoretical considerations are made on the excitation and its response. The fluctuation of the peak frequency is considered to be due to variety of the excitation expressed by frequency function of flush current I(ω). In order to change the peak frequency from the resonance frequency determined
by the frequency response function A(ω) of the earth-ionosphere cavity, high peak of the excitation I(ω) is necessary at a different ω. This is realized by multiple strokes of lightning flush.
