The equation of frequency of the atmosphric internal gravitational waves in model of two layers each of which has uniform wind speed and temperature lapse rate, with or without discontinuity of temperature itself is derived, in order to study the mechanism of microbarographic waves or pressure oscillations with period from a few to about 20 minutes. The equation is graphically solved and the explicit solutions of cellular and noncellular types are obtained.
High and middle tropospheric conditions of temperature and wind fields are analysed in detail for heavy rainfall cases of 26 June and 17 July 1953. In these cases the subtropical upper frontal zone is observed in the vertical cross sections in its well defined form. It is suggested that the vertical motion associated with this upper frontal zone might be one of the factors which induce the heavy rainfall over west and central Japan during the rainy season in early summer.
It is the purpose of this paper to make clear the height change of constant pressure with respect to time in the lower atmosphere. The vorticity change with time comes from the contribution of two factors; the one is the horizontal advection of absolute vorticity and another is the divergence or convergence of the horizontal velocity. The former problem is obtained from the calculation of the so-called Jacobian. However, there are many ways to estimate the latter one. In this paper, authors propose a method to calculate the divergence or convergence of horizontal velocity exactly. In this method we are able to take into account the effect of topography without any difficulty. The vertical p-velocity thus obtained is in good agreement with the observed one which is checked from the amount of precipitation due to dynamical and topographical effects.
The vertical P-velocity in a state of saturation is derived from the equation of vertical P-vorticity and the conservation of the equivalent potential temperature. The difference of vertical P-velocities in the dry and wet adiabatic processes are estimated. In the last section of this paper, the comment of the effects of condensation on the hight change are explained.
It is the purpose of this paper to make clear the condensation equation. Using this equation and the vertical motion computed from vorticity equation, an amount of heavy rainfall was calculated. In connection with this problem, the author attempts to calculate the amount of condensation of the vapour and vertical velocity under the assumption of not only dry adiabatic change but also moist adiabatic change of the air.
Typhoon Marie is noted for her unusual behaviour of redevelopment over the Japan Sea. An analysis is attempted under a supposition that such a situation can be explained by superposing an extratropical cyclone on the Main Typhoon. The results show that the development of the superposed extratropical cyclone accounts fully for the apparent redevelopment of such a typhoon, the Main Typhoon being considered to be at the decaying stage during that period. To say conclusively, the above mentioned supposition is confirmed synoptically in the present paper, leading to an important suggestion on the mechanism of redevelopment of the typhoon in the middle latitudes.
The variation of the angular velocity with height is examined for several typhoons and is found to exist a barotropic layer in the lower part of typhoon vortex, which leads to some conclusions concerning the travelling speed and the change of situation of typhoon.
In order to get a clue to the relation among the ice-nucleating activity of substances and their crystal structure, solubility and other properties, a thermostat-like cold-chamber functioning at any temperature higher than -20°C has been constructed and about 30 materials-oxides of cobalt, nickel, cadmium, magnesium and zinc, halides of alkali and alkalineearth metals and of silver, lead, and besides, cadmium sulfide, magnesium telluride, etc.belonging to either the cubic or hexagonal system have been examined as to the temperature of ice crystal formation. The main findings are described as follows: 1) The more closely the lattice constant approximates to that of ice and the more definite the insolubleness in water is, the more likely the substances, both cubic and hexagonal, are to exhibit marked ice-forming property. 2) Lead iodide and silver iodide are the most effective of the substances examined, the ice crystals being found to form from supercooled clouds at -2.3° and -2.9°C, respectively, in the presence of these foreign nuclei.