Presented are analytical formulations for a two-dimensional homogeneous turbulence associated with mean motion having a constant velocity gradient. The effect of the mean velocity gradient and that of the rotation of the earth on the rate of change with respect to time of the power spectrum of turbulence is shown.
The amplitude and the phase angle of the five harmonics for the mean values of 500-mb height along the 50°N lat, circle are investigated related to the characteristics of long waves on mean charts and the solar-activity. The split of developed ridges occurs generally in Europe in winter. This is connected with the horizontal wind shear at 50°N lat. and may be caused by the topographical effect. The amplitude of the first and the second harmonics are negatively and positively correlated with the sunspot-numbers respectively. This relationship holds also to the short time-change of the sunspot-numbers. The effect of the sunspot-activity is significant in winter and on 500-mb level.
A test of the barotropic forecast of typhoon movement at the 700-mb level is performed. In this problem, the stream function, obtained by solving the balance equation, is used in place of the geopotential. In spite of relatively small prediction area, the results of the numerical prediction of typhoon movement are fairly successful.
The synoptic structure of Typhoon Tess (1953) over the tropical ocean is examined to verify the development of a tropical cyclone into a severe typhoon from the viewpoint of Namekawa's theory of main and secondary typhoons. A hypothesis on the life cycle of a tropical cyclone is presented in conclusion.
Discussing the ionization equilibrium taking into consideration the influence of eddy diffusion, the writer (1) calculated the vertical distribution of the air resistivity in the exchange layer. In this calculation, the nuclei content was assumed to be constant with height. In the present paper, the vertical distribution of the nuclei content is assumed to be given by the exponential form, and the influences of the several coefficients of the decrement on the vertical distribution of the air resistivity in the exchange layer were calculated.