Prognostic charts of 5-day m ean 700 mb height were made experimentally since the last summer by the periodical extrapolation method and it was found that the accuracy of the forecasted values better than that of surface pressure. Next, the relations between daily weather progress and 5-day mean 700mb chart were researched and it was found that the prognostic 5-day mean anomaly chart of 700 mb level was useful for the forcast of 5-day mean temperature and weather change.
The methods hitherto in use may be considered to have no reasonable theoretical background and by some examples we proved that the goodness of fit by any of them is not satisfactory in general. We proposed a new method which consists of the following steps: 1) We estimate a “ normalizing transformation curve ” by which the empirical distribution function of logarithms of observed variates is transformed to a normal one.2) We extrapolate the normalizing transformation curve to not yet experienced region by utilizing the Fisher-Tippett s limiting distribution function for the largest member of a sample.3) By a two-sample theory we give the stochastic limits for the transformed normal variates corresponding to any given probability.4) Lastly we transform the stochastic limits inversely to that for amount of precipitation. The above method is based on the stationarity and randomness of observed time series; if it is not stationary we should use the data in the ‘ recent stationary period ’, and if it has any autocorrelation, firstly we should estimate the type of the stochastic process and then we use a generalized formula for the stochastic limits according to the type.
The periods of the atmospheric phenomena are supposed to differ from each other according to their scales, e. g., there may be a positive correlation between the magnitude of scales and length of periods in the atmosphere. The purpose of this paper is to investigate the statistical characteristics of the atmospheric disturbances of various scales and further to find out the mechanism of mutual transfer of vorticity and kinetic energy of mean flow and disturbances. If we succeed in this attempt, the results obtained from are expected to be useful also for such a forecasting problem as numerical prediction. In the present study the following characteristics of the atmospheric phenomena are dealt with, that is, (1) the so-called “width of perturbations ”, (2) the stationarity of variations, (3) the spectral distribution of pressure and (4) the kinetic energy spectra, employing the 36 term harmonic coefficients calculated from the values of 500 mb level along 50°N, 45°N and 30°N latitude circles in the Historical Weather Maps. The periods subjected to analysis are January (1946,1949), May, June and July (1951). The results obtained are as follows. First the component waves of disturbances can be classified into three (or four) parts. Then let n and F(n) denote wave number and spectral function respectively. The motion of waves of small wave number is non-isotropic, oscillatory and moreover F(n)=const. Meanwhile the motion of waves of great wave number is isotropic, progressive and F(n) ∝ n-7/3 as expected. Further it may be concluded that the mean flow and the component waves of n=1,2 belong to the former and component waves of n=≤6 belong to the latter region. Accordingly the components of n=3, 4, 5 are considered to constitute the region of middle wave number in our case. Next, the energy spectra indicate three sources of kinetic energy in the atmosphere, i. e., mean flow, component wave of n=3 and of n=6 or 7.
A combination wind vane and anemometer model (Marine Speedovane) is tested in wind tunnel, as to its mode of oscillation and variation of rotational speed in pitching or rolling motion with wind on. According to this model experiment the pitching motion of period of 8 seconds (actual weather ship's value) has nothing to do with the indication of the wind vane, but it seriously affects the rotational speed of the anemometer windmill, which is oscillating with the same period as that of the pitching motion and with a certain phase lag. The mean rotational speed is found remarkably lower than that without pitching at the same wind speed. In the rolling motion of the same period, however, the mean rotational speed of the anemometer windmill agrees well with that without rolling at the same wind speed. No definite periodicity and phase lag of the rotation are found in this case except a certain band width of fluctuations.
The design and the construction of a new radio-telernetering instrument for measuring raindrops employing filter-paper as a sensing part for the raindrops are described. The reliabilities of the method of the new radio-telemetering instrument are discussed. It is shown that the instruments are suitable for accurate measurements especially for relatively smaller drops.
Workman-Reynolds' theory of the acquisition of charges by ice particles, falling through a region containing supercooled water droplets, is worked out in detail; the altitude distribution of charge in a region of active thunderstorm and the amount of charge on an ice particle are shown. Our results show a good coincidence with the observed values obtained by ROSS GUNN.
The author observed a tidal current using his current meter and two others of different kinds simultaneously. He explained that the observed velocity fluctuation with the period of 1.5 hours was caused by the instantaneous penetration of the waters broken from the disturbance, and the time variation of velocity was due to the effect of vertical eddy viscosity and the change of the surface slope with time Further. he analysed the shorter period disturbance and found that its eddy diffusion coefficient K∼269 c. g. s, its mean length of edddy l∼124 cm.
Some of Japanese seismologists have been considering the effect of magma lying under the Earth's crust as the real origin of an earthquake, though there are some disagreements among them concerning what the effect of magma is: explosion or simple pressure. The authors have the opinion that the pressure of magma is to rise to break rocks surrounding its cavity and cause an earthquake, and theoretically investigate the relation between the shape of cavity and the breaking point around it. The two shapes, prolate and oblate spheroids, are dealt with, and it is assumed that one of these cavities is lying in an infinite elastic body, in which magma presses hydrostatically its boundary surface. The stress and then the deformation energy in medium around the cavity were calculated, and it is found that the points where the latter takes the maximum value were both poles for the prolate, and those on the equatorial circle for the oblate spheroid. These are considered to be the places to break at first according to von Mieses' theory. These considerations indicate that the points on a cavity with the smallest radius of curvature are liable to break first.
It may be said that the method using the radio-carbon is the best among others for measuring the oceanic productivity now. For the purpose to check and improve this method, the gross production of coastal waters was studied. The procedure was almost the same as that of E. S. NIELSEN. However, the direct measurement of the radio-carbon fixed in phyto-planktons with G-M counter was standardized by measuring ionization current in the carbon dioxide gas by Lauritsen electroscope. As the results of observations of coastal waters, it was ascertained that the diurnal change in the gross production was proportional to that of the solar radiation. Also it was found that the influence of the respiration of phyto-planktons and the wall effect of vessels could be negligible. In the same time, the total amount of phyto-planktons was determined as gaseous carbon dioxide by ignition. The simultaneous comparison was made between the productivity values by the radio-carbon method and the dissolved oxygen method for same samples and the considerable difference was found between them.
The authors made a new plastic water sampler as shown in Fig.1. The cylindrical tube of the sampler is fitted with a stem mercury-in-glass thermometer, or a reversing thermometer if we want, in its inner side; and it has two nylon ropes, each 20 meters long, one of which is graduated in meters. The instrument is lowered to the required depth head forward. Then the tube is at the upper end and the sampler is in the open position. It is allowed to remain there for about 3 or.5 minutes to permit the thermometer to reach the temperature of its surroundings, and as it is reversed by turning through 180 degrees by the other rope, the tube is slided down to the lower end of the sampler, and encloses a sample, to the amount of about 500 cc. Then we can measure the water temperature by reading the thermometer through the tube, and the specific gravity by a hydrometer. And the water is sampled from a drain tube of rubber at the lower end of the instrument. The heat conductivities of the new plastic sampler and the Kitahar's (a Petterson-Nansen type) were measured