The general characters of the vertical structure of the atmospheric disturbances are discussed, on the basis of the analyses of the aerological data in Japan during four winter months. The behavior of a deep stable layer is remarked dynamically. Particular emphasis is placed upon the rôle of the divergence and the vertical transport of the static stability.Consulting the analytical experiences, an atmospheric model which is fitted for the finer structure of disturbances is designed for thenumerical prediction. Rather finer structures observed in extratropical disturbances have some bearings on the strong concentration in the zonal current or on the strong baroclinicity of the atmosphere.
In section 2, we compute t h e height changes depending only upon the horizontal advection of absolute vorticity at each isobaric level, such as 300-mb,500-mb,700-mb, and 850-mb. The location of negative or positive height change centers at each level varies from level to level, and the so-called non-divergence level differs with individual typhoons. Referring to this fact, it may he said that the barotropic model is not always a sufficient one for the forecasting of typhoon movement. In section 3, the simplest method for taking into account the baroclinic effect is treated. Assuming the vertical distribution for ω to be parabolic, ω, and also ∂ω/∂p, are easily obtained by using the data at two selected isobaric levels. Examining the height change due to ∂ω/∂p at various isobaric levels, it becomes clear that the parabolic assumption for ω is not always adequate for the forecasting of typhoon. In section 4, the more complete model for baroclinic case is treated. Solving the differential equation of vertical velocity by taking up as many isobaric levels as possible, such as 300 mb,500 mb,700mb,850 mb and 1000 mb, we analyse the detailed vertical distribution of ω. The distribution of ω is somewhat complicated, especially in the lower atmosphere. It may be guessed for certain that the baroclinic factor ∂ω/∂p effectively contributes to the movement of typhoon. In section 5, the height changes for next 12 hours is de s cribed. The patterns of these changes involve considerable irregularities whose cause is not computational instability but truncation error or error of physical nature. In section 6, to a void these errors, a tentative method for smoothing the initial pattern is proposed. This method is a fairly satisfactory one, although it would not be the best.
By employing several kinds of effective chemical substance, soluble and insoluble, as ice crystal nuclei, the ice crystals were formed in a cold box within which the temperature was comparatively high, i. e. above -20°C, and their plastic replicas were observed through the optical- and the electron-microscope. The author could not tell the difference of crystal habits according to the various nucleus substances. Some dodecagonal crystals were found in the plates. As for the size of the nuclei, the smaller nuclei were seen with the lower environment temperature. While the size of AgI-nuclei which were effective above -15°C was larger than the order of 10-5cm, that of most AgIsmoke particles belonged to the order smaller than 10-6cm. On the one hand, according to almost all the pictures of the plastic replicas of the ice crystals which were formed with the smoke particle nuclei of low solubility such as AgI, Ag2S and PIDI2, their nuclei were seen near the center of the crystals. On the other, regarding the nucleus substance of high solubility such as AgNO3, NaI and NH4I, the existence of the nucleous particles was not recognized in the replicas of the crystals.
In order to find a clue to the present situation of the atmospheric pollution in Tokyo, two points near the atmospheric pollution sources in Tokyo city (Kanda and Arakawa) and one in Kawasaki city which seemed to exercise much effect on the pollution in Tokyo city were selected, and the concentration of SO2, CO2 and dust in the open air were observed 5 times per day during a week, from 15th to 21st February,1956. And also, H-CHO and NH3 in the air were observed at the same time respectively in Kanda and Arakawa. Depending on the results obtained, the characteristics of the atmospheric pollution in its source area were investigated. Especially, the SO2 concentration was compared with the concentration and its variation which were observed at 7 localities in Kanda and others last year.
An expression of the velocity of the streamer advance along a previously ionized channel in the lightning discharge is obtained on the basis of an equation which represents the time variation of the electron density in a channel. The expression shows that, as the electron density in a previously ionized channel tends to zero, the velocity of the streamer tends, as expected, to that of the streamer advance through the virgin air (i.e. of the pilot streamer). The numerical evaluation for the velocity is obtained by the graphical method in the case of the stepped streamer, where the reasonable model of the tip field of the streamer is assumed. The result shows that the velocity of the streamer thus calculated agrees fairly well with the observed value of the velocity of the stepped streamer in the lightning discharge.
To confirm our results obtained in our former paper that, when a prolate spheroidal cavity applied with hydrostatic pressure breaks, a cone-type distribution of initial motion with pull-sense inside may occur, as a first step, we studied in this paper elastic waves generated from a prolate spheroidal cavity when a force of harmonic type is applied. Here, prolate spheroidal coordinates are applied. As a result of numerical calculations, it is found that when the cavity becomes more slender and finally, a line source with finite length, a push-pull distribution of displacement of P wave occurs as the wave length is three times the length of the source. As forces considered here are harmonic type, we can not distinguish whether our obtained distribution is a cone-type with pull-sense inside or push-sense inside, but we can assure that push-pull distribution of initial motion might occur when waves are generated from a prolate spheroidal cavity of a certain shape whose wall is subjected to normal stress.
The swelling in the forenoon appearing in the diurnal variation curve of air temperature at Ocean Weather Stations “ Extra ” (39°N,153°E) and “ Tango ” (29°N,135°E), described in detail in the fourth of the author's present series of studies , may pretty well be explained by considering an adiabatic change due to the diurnal variation of atmospheric pressure.