The author intended to get a formula expressing the rate of evaporation of falling rain drops theoretically. Applying the theory of boundary layer on the falling rain drop we obtained a formula for the evaporation from the region between the forward point (i.e. stagnant point dynamically, point A in Fig. 2) and the separation point (point B in Fig. 2) of the drop: viz. where k: diffusion coef. of the water vapour through air, a: radius of the drop; R: Raynolds no. of the drop for the rate of fall; Co, C_??_: water vapour density (g/cm3) on the surface of the drop and in the air respectively. The flow in the wake of the drop is so complicated that we could not get the rate of evaporation from this region. So comparing with Fr_??_ssling's experimental formula we gave the formula M=0.233×4πka_??_R(Co-C_??_) for the rate of evaporation of falling rain drops. Comparing this with the result for cloud and fog particles which was obtained by the present author (Studies on Evaporation II and III) the rate of evaporation of water drops in the case of Co-C_??_=1 was illustrated diagrammatically in Fig. 4.
The aim of this paper is to analyse a spontaneous oscillation into some stationary one. A complex oscillation can be showed as the composition of some stationary ones. Let the position and the time be s and t respectively. We consider a function of them: F means the deviation of f from its own average value in case of t=const. Here we put: F(s, t)=S(s)T(t)+δ(s, t) and make the product of T(t) (function of time) and S(s) (function of position) nearest to F (s, t), which means to make Σt Σs δ2 the least. Then we find that S and T show the form and the change of intensity of the prevailing stationary oscillation from the statistical point of view. The same procedure may be applied to the analysis of residual δ(s, t), and we can get the secondary stationary oscillation. The same is the case with the thirdly and the other higher order oscillations. S(s) is determined by the following simultaneous equations: These equations are easily solved by the successive approximation. T(t) is derived from S and F by the following equation: S(s) calculated by the above equations determines a nodal line of oscillation. But we hope to find the real position of it. Let it be s=_??_. _??_ is described as follows: Then, S-_??_ gives the real form of stationary oscillation. As some examples of this method we have analysed the following three cases: (a) barometric pressure field of, the Far Fast in January, 1941. (b) potential temperature field of the Far East in January, 1941. (c) barometric pressure field of the Northernhemisphere in January, 1937. We have succeeded to calculate till the sixth oscillation. The first and the second stationary oscillations show a progressive one moving eastward in middle latitudes. On the other hand the third and the fourth components oscillate from north to south. The first oscillation of potential temperature varies sharply or slackly in gradient between north and south. Its variatlon of T(t) resembles with the case of the first oscillation pressure. It may be seen from the last analysis (c) that the first oscillation of pressure over the Northernhemisphere acts to develop or weaken the high pressure areas on the Eurasian and the North American continent and low pressure areas in the neighbourhood of Iceland and Aleutians. This may be regarded as the same oscillation with the first one in case of (a), Far East only.
The north-west monsoon in winter is transformed _??_y the evaporation from the sea surface on the way of travel across Tusima-Strait and the transfomation is shown by the increase of mixing-ratio. We intend to calculate its values when the flow is considered as stationary. As a result, we get mixing-ratio increases, on the average, 0.095gr/kg per hour. The increase of mixing-ratio is connected most closely with the wind velocity and its increase is proportional to the square root of a certain wind velocity, but when the wind velocity exceeds this range the increase is stopped and maintains almost a constant value on account of the convection and the eddy diffusion. It is shown that H. U. Sverdrup's formula on the amount of evaporation from the sea surface derived from the theory of boundary layer is very useful from the fact that the amount of evaporation calculated by the above formula is very nearly propor_??_ional to the actual increase of mixing-ratio in case of the large wind velocity.
The most part (about 90%) of the yearly yield of Sardine off the coast of Ibaragi Prefecture is usualy caught by “Aguri-Ami” and its fishing-grounds are shown in Fig I. As we see from the figure, sea-water in these regions is effected by land water. And these regions consist in the “Siozakai” (Oceanographical boundary zone) which were formed by the “Kurosio” branch current, “Oyasio” and river currents. So, I thought that the yield of fish largely depends upon the variation of water temperature and me_??_eorological conditions, and calculated the correlation coefficients between the yearly yield in the next year and the surface water temperature, rainfall or fog days in the present year of the sea-side observatories, and g_??_t the following table. The expression of the yield on Ma_??_ch (of the next year) becomes Y=0.26A+0.23B+0.28C+0.23D, and on October (of the next year) becomes Y=0.20a+0.24b+0.19c+0.23d+0.14e. By this method I got the following forecast: the yield of this year will be about 1, 900 millon “Kan” and _??_hat of the next year (1947) will be about 1, 600 millon “Kan”. (The average yearly yield is 2, 200 million “Kan”.)
The variation of the atmospheric potential gradient caused by the smoke of the locomotive engines was recorded at the Kuts_??_kake Railway Station and at the Kar_??_izawa Meteorological Station (about 400m from the railway). It is almost always positive and reaches to about 2, 000V/m at the railway station and about 300V/m at the meteorological station The density of the space charge in the smoke is about 5esu/m3 at the distance of 50m from the locomotive and about 0.05esu/m3 at the meterological station.
The simultaneous observation of the antenna-earth current, atmospheric potential gradient, density of space charge and atmospherics was made during January and February, 1944 and 1945, at Aomori during the snow-storm, and the dense space charge was found in layers of 10 meters from the earth's surface, while above this layer there was the space charge of opposite sign.
The variation of the atmospheric potential gradient caused by the cloud of eruption smoke of the Volcano Asama was recorded at the Karuizawa Meterological Station (9.4km from the crater). The variation is positive (about+300V/m) at first and then negative (about-1000V/m). It is concluded that the electric charge of positive sign is in the upper part of the cloud nd the charge of negative sign is in the lower part, and the quantity of the charge is about 0.4 coul, mb.
The atmospheric potential gradient near the surface of the captive balloon was measured at various heights from the earth's surface in different meteorological conditions. The bamboo-rod was erected on the surface of the balloon and Polonium-collector was attached to this rod. The lead wire connected the collector and the self-recording electrometer was fastened to the moorings. The potential gradient near the surface of the balloon is so much greater as the height of the balloon increases. When the balloon penetrates the haze-layer, the potential increases with height and reaches the maximum value and then decreases to the normal value with height.
The electric potential of the moorings of captive balloon and the electric current flowing from the moorings to the earth was observed at maebasi, Gumma Prefecture, on July and A g st, 1944. The atmospheric potential gradient and the density of space charge in the lower stratum was calculated from the observational results and compared with the meteorological results. When there was a haze-layer, the electric charge of positive sign is found in the layer and the charge of negative sign in the upper and lower part of the layer.
In the Summer, 1941, when the thunderstorm occurred, the atmospheric potential gradient was observed at ten places using the Benndorf's self-recording electrometer, the sadden change of electric field d e to the lightning discharge at five places by the antenna earth current, the electric charge of rain-water at five places, near Maebasi, Gumma Prefecture. Each observing places were separated with the distance from several to ten kilometers each other. Moreover at Maebasi the electric cond ctivity of the air was observed every day d_??_ring the Summer. The line of eq_??_al potial gradient was drawn on the map and it was found that the area of large negative val e concided with that of the th_??_nderstorm, and in this area there was small local positive area which was accompanied by the strong rain. By the simultaneo_??_s observations of the s_??_dden change of the electric field d_??_e to the lightning discharge, it was fo_??_nd that the s_??_dden change was small and occurred on both sides of the zero-line when the discharge was far away from the observing places, and the s_??_dden change was large and only on positive side when the discharge was in the neighbourhood. From the relation between the distance from the discharge and the amount of s_??_dden change of the electric field, it was conclnded that the most lightning discharge occurred between the lower negative charge distributed over the circular cylinder of 2km radi_??_s, extending from 4km to 8km from the earth's s_??_rface, and the upper positive charge over the cylinder extending from 8km to 12m. By projecting the respective discharge on the map it was _??_o_??_nd that the discharging spots shifted from the original region to another region drawing the zig-zag course as if in the random walking. The dimension of the region where the lightning discharge occurs has the diameter of about ten kilometers. The distance of consecutive discharge ranges from one to five kilometers, and its average is 3.5km. The electric conductivity of the air suddenly increases always when the thunderstorm occurs. The negative partial conductvity increases rather sharply than the positive. After the thunderstorm moved away, the conductivity recovers to its normal value exponentially. The half-value period of the exponential curve is about one hour.
The atmospheric potential gradient near the earth's surface due to the model distribution of electric eharge was calculated and the results were tabulated or shown graphically in the original text. The potential gradient due to two electric charges, positive and negative respectively and the line connecting them being not perpendicular to the earth's surface, those due to the straight line charge perpendicular to the earth's surface, those due to the charge distributed over a square sheet, those due to the charge over a circular ring were calculated.
The sudden changes of the atmospheric potential gradient on the occasion of the lighting discharge were recorded-at four or five station each separated by the distance of several kilometers in July and August, 1941, in the neighbourhood of Maebasi, Gumma Prefecture. The quantity of the electric charge neutralized by the lighting discharge is about 90 coul. in the average, which is several times greater than that obtained by O. T. R. Wilson and T. W. Wormell.
The distrib tion of temperature between the surface of the skin and the surface of the clotyes was measned by the thermocouple. The heat-loss from the body thrtough the clotyes was calculated from the observational resluts, the value of which was 1270-2350 cal/day. m.2. It was also found that the sense of coldness corresponded to the quantity of heat-loss.
About 10cm square pieces of towelling, hemp-cloty, beb-sheet, cotton-cloth and thin cotton-cloth were immersed in water and hung under the eaves and then the weight of the clothes was measured at 5 or 10 minutes intervals. The water content of the cloth decreases linearly at first and then exponentially. The extent of the latter part is 15-12% of f_??_ll water content. The water that decreases linearly is considered as that supported in the texture, and that decreases exponentially as that between the fibres. The speed of drying is abont 0.09gr/dm2. 10min when the humidity is 90%, 0.27 when 60% and 0.57 when 30%, On each ease the wind velocity is about 3m/sec.