It is necessary for the study of lightning discharge to observe its effects simultaneously by as various means as possible. To investigate electromagnetic effects of lightning discharge and electrical structure of thundercloud, the authors have constructed several apparata for the joint observation of thunderstorms, e. g., the lightning counter, the electrostatic fluxmeter and the atmospheric wave-form recorder for nearby thunderstorm. The record of lightning counter informs us of the average activity of nearby thunderstorms; and by the simultaneous recording of the lightning by using both the electrostatic fluxmeter and the wave-form recorder, we can accurately deliniate field-change caused by the discharge, which often has extraordinary complex character i.e., the duration of which reaches nearly 1 sec., and yet which involves rapid field-changes of the order of 10-5sec. As the results of the thunderstorm observation held in Aug. 1953 at Maebasi-city, the following conclusion can be pointed out as for the cloud flashes in the dissipating stage of thunderstorm: 1. Effective advance velocity of supposed dipole charges in the cloud in the course of the cloud discharge is found to be very slow, i.e. of the order of 10-6cm/sec. 2. The slow cloud discharge is accompanied by the small discontinuous differential type pulses of radiation field character, which can be surmised to result from the small but rapid discontinuous discharges in the course of the same slow cloud discharge.
Many snow flakes were photographed during 1951_??_1954 in Japan, and they were classified according to the purposes by four methods, i.e., their hystorical processes, shapes in falling state, sizes and crystal habits. It was observed that the snow flakes change their crystal states in the process similar to that of the fallen snow. Considering aerodynamically, the shape and velocity of snow flakes in falling state, a clue for presuming the uniformity of crystal habits in snow flakes was acquired. In the photographs of snow flakes hitherto obtained, it was found that in all types of snow crystals one snow flake is formed with the respective type only, while another with almost all combinations between the different types is formed. All the ways geometrically possible for the adhesion of snow crystals, namely, top-top, top-surface, surface-surface, surface-edge line, line-line, intertwined adhesion were found in the snow flakes. The top of branch of dendritic crystals plays a leading role in the adhesion mechanism between the crystals. From those results, it was presumed that the great snow flakes might be composed of snow crystals of dendritic type.
It was shown in the previous paper that harmonic analysis for many terms can be made more feasible by substitution with sets of simpler analyses, if the total number of terms r can be put equal to m×n, where the integers m and n are incommensurable. The present paper deals with the procedures to be taken for the case where the m and n are arbitrary integers, and gives an example of analysis for 12 _??_ 12 terms schematically.
Using 2-layer model which is the special case of the multiple layer model defined by Charney and Phillips, investigation is made, from the view point of numerical weather prediction, on the role of the tilt of trough relative to the vertical for the development of the pressure pattern. At the same time, the mechanism of the transition between the tilted and the non-tilted trough is discussed. Finally, corresponding to the above development, the energetics of westerly wave, i. e., the energy exchange between the potential and the kinetic energy is investigated. Here, the simple expression for the change of these energies is obtained.