Memoirs of the Kakioka Magnetic Observatory Supplement No.02， p.93, March, 1966

The Geomagnetic Variations of Daily, Monthly and Annual Means and World-Wide Distribution of Daily Mean(Part 2)

Kuboki, T.

Abstract

 In a previous paper (Part 1), the author investigates various characteristics of geomagnetic long term means, such as daily, monthly and annual means，for the purpose of clarifying statistically the influence of the external field upon the geomagnetic mean values, and also preparing some basic information about the inner part of the geomagnetic field and secular variation of the geomagnetic field.
  In this paper (Part 2), the author investigates the world-wide distribution of the rate of change of daily mean values, normalization of results of various geomagnetic surveys, and interrelations between the hourly values at Japanese permanent observatories. The results of investigation are as follows.
  Though the data near the geomagnetic equator are few and scattering of data is large in higher latitude of Φ＞60°, the ratio of daily mean value of horizontal intensity at each station to that of Kakioka, H/Hκα, is proportional to cosΦ. The daily mean values of D are less in change compared with H. and show no such definite distribution law in o of the rate of change as H, although the distribution in Japan seems to be proportional to sinΦ. The distribution of the rate of change of Z is less regular，but approximately proportional to sinΦ. The distribution for Z/H is proportional to tanΦ in middle and low latitudes，and in Japan there is not found such a remarkable local anomaly as established for short period changes (so called “Central Japan anomaly").
  It is noted that the distribution of noncyclic change of the horizontal component by A. T. Price much differ from that of H or F in the present investigation in the eastern pacific ocean.
  In case of the treating the results of geomagnetic surveys and also the variations owing to the inner part of the earth, if one considers that various mean values show a linear correlation for each component (at Japanese permanent observatories) such as results in the previous paper (Part 1), one can easy eliminate the influences of the external geomagnetic field.
  As the interrelations between the hourly values at Japanese permanent observatories, Kakioka, Memambetsu, Kanoya and Simosato are very complicated, there is no simple correlation in those cases unlikely to the daily mean values etc.

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