A new expression A0+A sin (σt -γsinσt+ε) is suggested by the author to show the diurnal variation of air temperature. Method for finding the four constants A0, A, and is given and its applicability and the degree of approximation are discussed by some actual data. Physical remarks and some applications to climatology are also given in this paper. A noticeable success is the discovery of an expression with only the diurnal single period, not containing the semi-diurnal or other higher harmonic periods which are of no physical significance.
whether does the heat released by condensation actualy affect the large scale pattern or not? In order to answer this question, we examined the conservation of the potential vorticity and potential temperature in rainly regions for 12 hr period. At the same time, computing the 3-dimensional distribution of 12 hourly condensation by using the continuity relation of water vapour, we estimated the expected amount of the individual change of potential vorticity, and compared it with the observed one. As an example, a case of medium intensity of rainfall was taken, and it was found that the change of potential vorticity in the condensation region was small and hardly detectable. However, for the second case, when the extremely intense and large scale precipitation occurred, considerably large change of potential vorticity which has the same sense with the expected one is observed. Finally, the quantitative discussions about these two cases are performed.
The energy of the waves in question is calculated in order to show its variation with wave length under fixed atmospheric structure. A condition of minimization of this energy is proposed for the predominance of the microbarographic waves. Numerical solutions of the frequency equation for some simple atmospheric models are shown to illustrate the general behaviour of the possible waves in different atmospheric structures.
Observation of hourly atmospheric dust concentration by an automatic air sampler has been carried out from Feb. 1955 on the level of 53m above the ground at the Institute of Public Health. The mean hourly variation of dust concentration for each month was similar to the result obtained by other investigators but slightly differs from them. In this survey, the concentration in the morning had two maxima from April to September. The dust concentration in the midnight decreased exponentially with elapsed time, and the dissipation coefficient k increased linealy with wind velocity. From our analysis, it may be concluded that on the day with unstable atmospheric condition the particulate matters in the atmosphere are dispersed by turbulence caused by solar heating rather than wind. Under the meteorological conditions of rainy days, the concentration of smoke near the ground had a increasing tendency in the day-time, rather than decreasing one due to the washing effect of rain.
Electric charges of single raindrops were simultaneously measured for their sizes and surface field intensity under thunder clouds at Kiryu and Yokohama. It was found that a definite inverse relation between the signs of charge and field existed in Japan also, except during the short period when the sign of the surface field changed. The reason of this exception was considered as follows. During the period when the sign of field changed, the field intensity was almost zero. Therefore, the charges of falling raindrops suffered no charge deformation as a result of the capture of ions according to Wilson's theory. Considering the phenomena, one can explain the wide divergencies observed in the relation between charge and field. To examine Smith's calculation, it is desirable that the charges of many raindrops be observed within a short period in which thee field intensity is considered to be constant.
The details of ocean waves caused by typhoons and hurricanes have been uncertain owing to the lack of precise and successive data, and difference and confusion of opinions are found with respect to the speed, travel time and direction of waves. The author tried to make the actual states clear using the data obtained by the visual observation at the ocean weather station TANGO (29°N, 135°E). The period of high waves due to typhoons are usually 8-16 sec and remarkably longer than that of waves due to extra-tropical cyclones. They travel with the group velocity 20-45 km/hr which is not so large as believed by some people. It sometimes necessitates three days or so for conspicuous swells issued from a typhoon in the far south sea to reach Japan after the typhoon left to the west. The direction of swell relative to the center of storm is not so simple as stated by Cline(5), Tannehill(6) and Otani(7), and the magnitude of the deviation of swells from wind, mostly to the right, depends on the path of typhoon till that time, its speed relative to the sea waves and the stage of development of the typhoon. Figs. 4-8 show the scale and direction of wind waves and swell, period and height of prevailing waves in relation to the position and direction of movement of the center during the passage of respective typhoons. Fig. 4 represents a case when the typhoon rapidly developed, accordingly wind waves (or wind waves of swell type) prevailed with the same direction as that of wind. Figs. 5 and 6 are cases when the typhoon moved straightly with a larger speed of 50 km/hr than that of swell, and we find that in the front of the center the wind waves due to wind at that place prevailed but in the rear of the center conspicuous swells appeared with a direction different from that of wind waves. Fig. 7 shows a case when the typhoon with a small speed of travel turned the direction of movement drawing a large arc, and swells with a direction different from that of wind waves were seen in the front of the center as well as in the rear of it. An example in August of 1935 shown by Tannehill corresponds to this case. Fig. 8 is a case when the typhoon with a small speed of travel turned to the right at a somewhat steep angle, and it is easily understood that the state of sea was remarkably confused all over the ocean covered by the typhoon. In every case, we can conclude that the waves in the rear of the center were conspicuously higher and more confused than those in the front of the center, and this is in direct opposition to Cline's opinion. Speaking of the rear segment, the wave is rather high in right quadrant than in the left quadrant. Moreover, though it was already shown by Otani(8) and Arakawa(9) that terrible pyramidal waves are likely to occur in the right rear quadrant of the storm, they may also occur in the left rear quadrant because two systems of strong waves with different directions of travel may appear and collide with each other as seen in Fig. 5