抄録
Simultaneous records of the atmospheric electric potential gradient at three stations which make a regular triangle with sides of about two km, were compared with each other during the period of January 8-13, 1956, including a cloudy day as well as fine days. Expanding the daily course of the potential gradient on each day and at each station into Fourier series of 12 terms, the spectral distribution of the square of the amplitude of each component was obtained and the spectrum of the field was given by n-4 in an undisturbed day, n expressing the harmonic term. On theoretical grounds, assuming the distribution of space charge concentration characterized by its scale and its density within the lower layer of the atmosphere, the spectral distribution of field energy was suggested to be represented by n-7 in the intermediate range of n. The result was proved to be consistent with the above analytical result. The factor causing the disturbance in the spectrum was looked for into the atmosphere using the aerological data. It was found that the turbulent situation of the air in the lower altitudes up to three km would control the structure of the atmospheric electric field.
