Simultaneous Comparisons of CA Transfer Functions Between Kakioka and Iwaki
Sano, Y. & Nakaya, K.
Abstract
Simultaneous comparisons of CA transfer functions for the periods of 45, 60 and 90 min. between Kakioka and Iwaki have been carried out for the period from July 1977 to Mar 1978. The transfer functions at both stations are calculated by the quite same way; the least square method for Fourier transforms of many geomagnetic disturbances.
From the present comparisons various important results are obtained. Some main results for Au and Bu transfer functions are as follows:
(1) Time changes of the transfer functions at Kakioka and Iwaki and very resemble, in particular，for the 90 min. period componet.
(2) Several decreasing changes in the transfer functions related to some earthquakes near Kakioka or Iwaki can be identified. However, it is not so clear that all of the above parallel time changes at both stations are due to internal origins.
(3) General period characteristics of the transfer functions at both stations are also considerably resemble，especially in the case of Au transfer function.
Some kinds of the time changes of the functions may be related to the extemal disturbances. In order to separate the internal change part from the external one, simultaneous comparisons of transfer functions at the other stations as many as possible near Kakioka are highly required.
