When the harvest of rice in the North-Eastern Japan is very poor, the harvest in the Western Japan often seems to become also poor, and similarly for good harvest. This may be considered to be caused by some macroscopic weather. Thus the distribution of air masses in summer is investigated and following results connected with rice-physiology are obtained.
In good harvest year, the ogasawara air mass (mT) prevails almost whole July and August, but in poor harvest year the Okhotsk air mass (mP) or the Siberian air mass (cP) prevails freaquently in summer which generally produces cold, cloudy and wet weather;
Owing to this bad weather the harvest o rice becomes poor not only in the North-Eastern Japan but also in the Western Japan. Therefore, in case that the poor harvest is forecasted in the North-East we should also be anxious about it in the West.

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The Climate of Japan has been studied from the view of the air-mass calendar. In the cold season (September to June), Japan is decidedly under the influence of the Siberian Air Mass. In the mid-summer (July to August), the North Pacific tropical air controlls the weather of Japan. Sometimes in the early summer, the North Pacific polar air comes from the northeast and results the gloomy weather. Monthly percentage frequencies for each air mass type were tabulated in the Table for 4 representative stations (Fukuoka and Takamatsu for W-Japan, Tokyo for E-Japan and Sapporo for N-Japan.)

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The daily discharges of two streams, at Kamabuchi local station, Yamagata prefecture, of Forestry Expreimental Station, were used to study the effect of air temperature upon the thawing of snow ; the following results were obtained.
1. The degree-day factors were calculated by the mean daily maximum and minimum temperatures. The values of the degree-day factors seem to increase with the daily mean temperature. This fact is seen also on laboratory experiments.
2. If the forests were cleared, the values of this factor increased.
3. At the beginning of thawing, this factor is lager as the water equivalent of snow is large.
4. The total amounts of thawing snow of one season measured by the Thaw meter used in our labaratory or calculated from discharge of a small stream were not same to those measured by snow guage, and their relation differs by snow amount of a season ; i. e. the amounts by thaw meter or discharge were greater than those of snow guage when total amount in a season exceeds 800-900 mm. and vice versa.
5. The daily amounts of the thawing snow appear to be less influenced by the solar radiation, because the effect of the greater solar radiation in fine day is cancelled by the freezing temperature in early morning.
6. For the similar daily temperature, the weather of polar air mass seems to bring forth smaller thawing than that of maritime air mass.

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The author intended to study how the contraction of the puerperal uterus varies with the climatometeorological changes. For this purpose, the climate and the weather of Japanese Islands (especially Tokyo district) were classified into 4groups by Arakawa's method : namely, Siberian, Yangtze, Okhotsk, and Ogasawara air masses, and each group was further divided into 4 parts, namely under the influences of High, Low, stagnant Front and others. Among all parturitions at San-iku Kai Hospital (Tokyo) in 1950-1951, 2466 primiparae and 2484 multiparae who had normal puerperal courses were selected. The degree of the contraction was represented by the length of the uterus fundus. The contraction of puerperal uterus under each climato meteorological condition was investigatedstochastically. The result obstained is summarised as follows : 1. Under the influences of Low the contraction is fast. 2. Under the influences of High the contraction is generally slow. As to the seasonal differences, it is faster in winter (Siberian air mass), slower in summer (Ogasawara air mass) and moderate in spring, autumn and the rainy season (Yangtze and Okhotsk air masses). This finding indicates the essential and representative seasonal variations of the puerperal uterus contraction. 3. Under the influences of stagnant Front the contraction is moderate. 4. When the air masses were compared with each other by disregarding meteorological conditions, the contraction is fast in spring and autumn (Yangtze air mass), slow in summer (Ogasawara air mass) and moderate in winter and rainy season (Siberian and Okhotsk air masses). Here, the finding indicates the average seasoaal variation of the puerperal uterus contraction. Finally, the influences of climato-meterological changes on the contraction of puerperal uterus were discussed in relation with the autonomic nervous system and posterior pituitary hormones.

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Since the establishment of meteorological observations in Japan, the climatic factors in winter and summer change in parallel with the 11-year running means of the sunspot relative numbers, though the parallelism does not hold after about 1940. The mechanism which governs the trends is considered to be as shown in the following table and vice versa, according to Simpson's theory on the glacial and interglacial ages. The connection seems to be inconceivable, but it is presumed that in the Okhotsk Sea it was warmer in glacial ages in the quarternary period than at present.

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Various natures of summer weather in Far East Asia were investigated for the purpose of short and long range weather forecasting, and the results are summarized as follows.
1) The alternation of weather is slow and the diurnal variation of various meteorological elements is quite distinct. Hence, daily weather is predicted by air-mass analysis of morning observation.
2) One of the most important factor which controles the weather is Ogasawara high. Most depressions in summer, say, typhoon, one of the most distructive storm of the world, travel clockwise around Ogasawara high. If there is no depression about Ogasawara high, tropical maritime air-mass is brought from Ogasawara and usually continues fair weather.
3) On an average, six depressions lie around the Ogasawara high, and 5 days periodicity of pressure is explained by the drift of the depression due to the upper wind.
4) The velocity distribution at the surface in Ogasawara high is given by provided that circular symmetry of Ogasawara high is assumed, where V is velocity, r distance from the center, V_o, r_o are constants. Such a distribution agrees with the distribution of pressure as it should be and the descending current in Ogasawara high is estimated to be about 2.5mm/sec.
5) Thermodynamical nature of Ogasawara air-mass is calculated from the condition of the equilibrium of energy transfer of various kinds and the lapse rate of temperature is calculated to be about 0.5°C/100m.
6) When the cold air of high latitude invades in low latitude, say, about N 40°, rainy weather is expected at northern part of the main island of Japan.
7) Water vapor which evaporates from sea in the domain of Ogasawara high can be considered to diffuse in all directions and the coefficient of diffusivity is calculated to be about 3×100⁹cm²/sec
8) Thunder storms in the season are classified into two kinds; one is the outbreak of instability due to invasion of cold air, the other due to ascending current caused by insulation, and they have different structure. It is shown further that every strong heat thunder storm has warm sector like a polar front depression which is important for the practice of the prediction of heat thunder storm.

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The alternation of weather in early winter in the Far East was researched from various points of view.
1) The weather in the season was considered to be due to a flow of cold Siberian air-mass and it was remarked that the weather of Japan depends on the nature of Siberian air-mass. For example, if the temperature of Siberian air-mass becomes cold, the temperature of Japan also becomes cold though there is a small time lag, say a day. The velocity of the flow was estimated from the time lag to be about 35km per hour. This agrees approximately with the velocity of cyclone and the mean velocity of monsoon.
2) Japan lies on the frontal zone between Siberian air-mass and Ogasawara air-mass, and it was shown that the path of depressions lies on a band which coincides with the frontal zone. Next, the weather was classified into two types; one is the so-called “west high and east low”, the standard type in winter, and the other is the cold front type which runs from SSW to NNE. Such a front was investigated and it was found that, on an average, the temperature difference is 3.7°C, the inclination of the front 1/130 and the velocity 43km per hour.
3) The climate in the season was considered as a diffusing process of Siberian air-mass and the diffusion coefficient was calculated from the distributions of vapour tension and temperature. The obtained value was about 5×10⁹cm²/sec.
4) The flow of energy across the frontal zone was calculated and it was found to be about 2.6×10cal/min/cm. Next, it was shown that, if there was no such flow of energy, the temperature of Siberia would become cold much faster, probably about 2 times faster than the actual. Next, the dissipation of kinetic energy of monsoon was estimated to be about 10³erg/sec/cm². And considering the monsoon a heat engine, its efficiency was calculated to be about 8%.
5) One of the typical weathers in the season is the outbreak of high accompanied by cold spell. Considering that such an outbreak was the outflow of cold air accumulated over the continent of Asia, the equation which gives the change of pressure was calculated. The equation is
where Δp is anomaly of pressure, ΔT temperature difference between lower and upper layers, h height of the lower cold air, v kinematic eddy viscosity, g acceleration of gravity, l Coriolian factor and α the angle between surface wind and gradient wind. This equation is the so-called diffusion equation and it was shown that the outbreak of high can be explained approximately by such an equation, through putting the coefficient to be about 10¹⁰cm²/sec.
6) Lastly, the 7 days' periodicity of the weather was discussed and it was attributed to the oscillation of cold air over the continent of Asia. Solving the equation derived from such an assumption, the period was calculated to be about 7.5 days, which was quite in accord with the 7 days' periodicity.

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Synoptic charts are classified according to the path of typhoon and it was investigated whether the path of typhoon is affected by rainfall or not. It was found that the typhoon travels on rainy region which is explained by the frontal zone betweep Ogasawara and Siberian air-masses.

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日本に来襲する気団を高層観測資料から求めた偽湿球温位を用いて分析し その気団によつて運ばれて来た放射能塵の発生地と径路をしらべてみた
ビキニ・エニエトツクの核爆発実験によって生じた放射能塵はによつて運ばれ日本に来襲し 北極圏からのものはシベリヤ気団によって運ばれて来るが南西シベリヤからのものは上層の強い偏西風によって西から来襲する場合と シベリヤ気団にのって北から来襲する場合とがある また核爆発後3ケ月以上もたつと その源とは無関係にあらゆる気団内でその放射能塵が観測される

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琉球列島地下水のδ¹⁸Oについての緯度効果は本州よりも小さかったが，それは琉球列島に降水をもたらす気団に亜熱帯海域に起源をもつ水蒸気が持続的に補給されているためである。石垣島の降水のδDおよびδ¹⁸Oの値は，主に夏季に低く冬季に高い。また，降水のd値は夏季に低く冬季に高い。夏季の降水は湿潤な太平洋気団に起源をもつd値の低い水蒸気団によってもたらされ，冬季の降水は大陸からの寒気の吹き出しの影響を受けている。同位体組成に及ぼす雨量効果は年間を通して現れ，夏季には２つのパターンが観測された。琉球列島の夏季降水のd値はほとんど同じ(約10)であるが，冬季には種子島，屋久島および中之島の値(＞25)は，それら以南の島々の値(＜22)に比べて高くなることが推定された。

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Characteristic natures of the alternation of spring weather in the Far East Asia were investigated and the results are summarized as follows.
1) Mean velocities of the motions of cyolone, anticyclone, rainy region, line of discontinuity and yellow sand are calculated and it is shown that the movement of lines of discontinuity and yellow sand are quite differnt from the others.
2) The velocity of cyclone is determined by up, er air current and nature of frontal zone between two air masses. When the effect of frontal zone is predominated, the cyclone is considered as to be the wavy motion of the frontal zone. This is treated mathematically under a simple assumption and travelling of cyclone towards east is proved.
3) The motions of discontinuity and yellow sand are determined by out flow of cold air from Asiatic continent and its motion is calculated.
4) Characteristic nature of the season is oscillative change of various meteorological elementswhich can be explained by the wavy movement of frontal zone between Ogasawara and Siberia air masses.
5) It is shown that there is a special weather which can be considered as a diffusing phenomena of Ogasawara air mass in horizontal direction and the amount of precipitation is calculated by solving the equation of diffusion and the results are satisfactory.
6) Statistics of characteristic weather for various air masses are made.
7) Structure of the typical cyclone of the season is investigated and it is founl tbat it resembles to the eyclone in Europe as a whole, but the direction of movement is different, hence the alternation of weather due to the passage of the cyclone is rather different from that in Europe.

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The purpose of this report is to study the relationship between soil temperature and geographical location (altitude andlatitude). The air temperature is expressed as the function of latitude φ and altitude H, and the experimental equation is expressed as follows; spring θa=43.5-1.07φ-0.0056H* summer θa=36.7-0.52φ-0.0050H* fall θa=43.4-0.93φ-0.0050H* winter θa=44.2-1.33φ-0.0060H* annual mean θa=40.7-0.93φ-0.0052H* H*=H-1,000 These eqations indicate average air temperatures of three months in each season. The following are the experimental equations to get the variation of the air temperature (Δθ) in each season. spring Δθ=0.32φ-0.6 summer Δθ=0.28φ-5.3 fall Δθ=0.30φ+0.8 winter Δθ=-0.07φ+5.3 The average lapse-rate of air temperature in mountainous region are 0.59℃/100m in spring, 0.56℃/100m in summer, 0.58℃/100m in fall, 0.72℃/100m in winter and 0.61℃/100m in annual mean. The lapse-rate of air temperature is greatly influenced by the arid Sibelia air-mass in winter and by the humid Ogasawara air-mass in summer

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