A New Index of Geomagnetic Pulsation and Its Relation to Solar M-Regions, II, Analysis of the Data from 1959 to 1964

Abstract

The result of Part I of this series is amplified by using the data from 1959 to 1964.
It is pointed out that the superposed epoch method which has been used for the solar M-region study may draw many diverse conclusions. Contraversity among four hypotheses, Allen's, Mustel's, Dessler-Fejer's and Piddington's, on the mechanism of 27-day recurrent geomagnetic disturbance is partly due to obscurity in the superposed epoch method. In order to obtain exact locations of M-regions in relation to solar active regions, a geomagnetic pulsation pc 3 and calcium plage are applied as the representatives among various solar and terrestrial phenomena. An M-region temporally obtained by putting ∑Kc 3, the daily sum of pc 3 index, back by three days is called an apparent M- (or AM-) region. All diverse relations between AM-region and active region obtained by the superimposed method cannot be uniquely interpreted by any of the above four hypotheses. It is shown that such the different relations cannot be interpreted by a radial solar wind emission from the sun, which is the fundamental assumption especially in both Allen's and Mustel's hypotheses. Thus, the deflection hypothesis based on the following assumptions is introduced. (1) The solar winds with high velocity responsible for M-disturbances are emitted generally in the non-radial direction with respect to the solar surface. (2) Most of the wind particles are supplied from a region of Ca plage or of its remnant (abbreviated to PR-region). This hypothesis is applied for a practical explanation of the different relations between AM- and PR-regions which have appeared during the present solar cycle.