Principal Magnetic Disturbances at Kakioka, 1924-1951
Yokouchi, Y.
Abstract
Characteristic of some principal magnetic disturbances recorded at Kakioka from February, 1924 to December， 1951 are given in the tables 25 and 26.
In the tables，the following items are given : the times of beginning and ending of storms, times of beginning of main phase and last phase，the times at which the minimum value of horizontal intensity occurred，and the maximum ranges of storms.
For the sudden-commencement，amounts of sudden movement of declination (D)， horizontal intensity (H) and vertical intensity(Z) are given，respectively, and the duration of time is measured on only horizontal intensity.
According to the character of magnetic disturbances，they are classified as follows:
SC (a): Magnetic storm with sudden-commencement followed by ordinary storm process，that is，initial， main and last phases can be discerned.
SC(b)): SC(a) type storm，but distinguished from Sc (a) as folows:
1). Sudden-commencement followed by rather inactive duration longer than several hours before beginning of main phase.
2). Sudden-commencement followed by moderate active duration longer than several hours in which some other commencements may be contained， before beginning of main phase.
SC (c): Magnetic storm with sudden-commencement followed by the irregular variation，each phase not discerned.
1: Magnetic disturbance with sudden-commencement followed by small disturbance except polar or pulsational sudden-commencement and magnetic crochet associated with solar flares.
G (a), G (b) and G (c): Storms with gradual-commencement and the characters corresponding to SC(a)， SC (b) and SC (c)， respectively.
For the classification above-mentioned，the horizontal intensity H is principally taken into account，and G's are tabulated only when their maximum ranges in H exceed about 70γ.
Some statistical results are given in the tables 1-24，and are shown in the figures 1-13.
