Abstract
A statistical survey of the sudden commencement of magnetic storms shows two remarkable properties; in the first place, the mean freauencv distribution of horizontal component H becomes non-symmetrical like the Pearson type, and in the second place, diurnal variation of H becomes W-type. After variation analysis we find that the variation in frequency distribution consists mainly of the energy variation of the corpuscular mass which is the cause of magnetic storm. This energy distribution is explained with an assumption that the sun-spot consists of a violent turbulence in which exists quasi-thermal motion by large scale masses of ionized gas which may be emitted from the sun as a unit. Wtype diurnal variation of H is explained as a complex phenomenon firstly with the primary field strength variation on the earth's surface produced by induced current on the front surface of corpuscular mass, and secondly the shielding effect of the ionosphere of the earth. The corpuscular theoy by Chapman and Ferraro is given support by our results even in numerical details, except that the conductivity of the earth's ionosphere must be by the order of 10-1-10-2 smaller than that expected from dynamo-theory of diurnal variation field. A rough estimation of the corpuscular mass is also attempted, and the values thus obtained are not so extravagant and inconsistent with that obtained up to this time.
