Abstract
In the winters of 1960 and 1961 respectively, two kinds of simultaneous observations andmeasurements were carried out in order to get some data as to the main factors such as the surface electric potential gradient, the charge on snow particles, the falling rate of snow and the forms of snow particles.
First, these four factors were measured at two stations installed about 1.2km separated each other along a line on which a shower-cloud often passes. Enough satisfactory data, however, could not be obtained at these two stations, so the surface electric potential gradient and the charge on snow particles were simultaneously measured at another two stations at different altitude, that is, at the Cloud Physics Observatory on the top of Mt. Teine (1023.7 m M.S.L.) and the Paradise Hut about 500m lower than the top.
Through these observations, the following points were noted :
(1) the origin of the inverse relation between the sign of the surface electric potential gradient and that of the charge on precipitations
(2) the space charge effect of the charge on precipitations on the surface electric potential gradient
(3) the difference of electrification of shower- and thunderclouds
(4) the existence of the difference between the conclusions obtained at the lower and the higher part of the mountain
From these observations some interesting results were obtained.
