The factors influencing photosynthesis are chiefly light-intensity and temperature, the former being most important. Therefore, it is important to study the relation between the diurnal change of the amount of dissolved oxygen in the water produced by the photosynthetic reaction of aquatic plants and the solar radiation which is the amount of sun-light. The Ohori, a shallow moat, situated near the Central Meteorological Observatory, Tokyo, is characterized by the high oversaturation of oxygen due to the vigorous activity of Phanerogamous aquatic plants, such as Potamogcton cripsis L. and Hydrilla verticillata var. Roxburgii Casp. which grow in the moat luxuriantly in the warmer season, and, in addition, the great abundance of phytoplankton in the water. It is a suitable microcosmos to learn the mutual relationship between biocinosis and biotop. Observations were made from 26 to 31, March, 1932. On 30, the dissolved oxygen contained in the surface water was 7, 39c.c. per liter at 7h. and 11, 42c.c. (150% in 100O2/O'2) at 18h., which was the maximum of the day, and after then it decreased gradually. The maximum at the surface layer came about an hour later than that at the bottom. As far as the present observations were concerned, the author could not find out the relationship numerically between the O2-production and the amount of the solar radiation correspondingly for the unit time, still it is recognizable that a lineal relation exists between the increased volume of O2 from the early morning and the amount of the solar radiation which was summed up from sun-rise till each time of the observation. The correlation coefficients are +0, 94, ω=±0, 069 and γ=+0, 96, ω=±0, 064 at the surface and the bottom layer respectively on March 30. As regards the fact that, in spite of rapid waning of the solar radiation in 16h.-18h., the amount of O2 is still increasing, the author reserves to dare to explain and awaits more exact experiments and further studies.
As the Ohori, where the limnologicol observations have been made by us since March, 1931, is highly entrophied and in the warmer season abundantly populated by aquatic plants, PH rises to above 9, 6 due to the strong photosynthesis. The seasonal variation of PH was fairly well correlated with that of the quantity of aquatic plants. PH was 9, 3 - 9, 5 and 9, 6 at 8h. and 16h. respectively during warmer season from the middle of May to August and then decreased suddenly to 7, 5 at 8h. on October 16, the bottom flora being decayed at the time. In the winter, PH maintained its value between 8, 0 and 8, 5 and the diurnal fluctuation was very small, if any, while at early spring PH rose to 8, 9 at 8h. and to 9, 5 at 16h. The seasonal variation of PH ranged from 7, 5 to 9, 7, the amplitude being 2, 2; the greatest amplitude of the diurnal fluctuation in all seasons was 0, 8 observed on September 23, 1931, the range of variation being from 7, 6 to 8, 4. The fact that PH in the Ohori does not show acidic reaction even in the winter is especially interesting as there is no record of the type of “Gypsotropher Fazies” in the fresh water of other places of Japan.
Isothermal lines were drawn on the map using the maximum and minimum air temperatures at several meteorological stations distributed over Tôkyô and its vicinity. And the effect of sea, field, hill and city on the minimum temperature was investigated.
The vertical distribution of the air temperature and humidity near the water surface was observed at a valley in Mt. Nasu. The observed values are tabulated and illustrated in the present note. The distribution was considered theoretically, assuming the eddy diffusivity azn, and n was determined as nearly 4/5.
In this paper, is treated a simple geometrical method for locating the position of earthquake focus by the arrival times of initial phase observed in the seismograms of several stations near the epicenter. The propagating velocity of seismic waves is assumed to be constant everywhere in the crust, but some considerations are also made in the case that the velocity increases with the depth.
The water waves in three dimensions were studied by using both cylindrical and Cartesian co-ordinates. For water, the coefficient of kinematic viscosity, ν is small, hence we can conclude as bollows: I. The velocity of propagation of the waves is almost the same with that in an ideal fluid. The modulus of decay is λ2/8π2±, λ being the wave length. The motion is nearly irrotational one. II. By slight modifications, we can discuss the seiches of lakes, also. III. The effects of atmosphere on water waves are negligibly small. The effects of eddy viscosity were discussed, not fully.
In this paper we investigated the abnormally high or low values of the air temperature which are accompanied by those of the neighbouring sea surface temperature and further whether the sea surface temperature has the effect upon the neighbouring air temperature and vice versa. The investigation was made at the eastern coast of the Ôu and Hokkaidô. At first we compared the anomaly of the monthly mean of the sea surface temperature with that of the neighbouring air temperature. Then the rates of the coincidence of the sign, plus or minus of the two anomalies and the rates of the parallel cases in which the increase (decrease) of one anomaly is accompanied by the increase (decrease) of the another are 70-60% in each case. But the former is a little larger than the latter. Next, we investigated the effect of the sea surface temperature upon the neighbouring air temperature. We calculated the rates of the parallel cases and opposite cases in the two curves, the difference between the anomaly of the air temperature of the next month and that of this month and the difference between the anomaly of the sea surface temperature and that of the air temperature of this month. The same was done with respect to the case of the effect of the air temperature upon the sea surface temperature. From these we obtained the following results. (i) In the former case the rates of the parallel cases are 70-60% and in the latter case those are a little smaller. (ii) The effect of the sea surface temperature upon the air temperature is greater in the case of the local sea surface temperature than in the case of the mean sea surface temperature of a large region, and the effect of the air temperature upon the sea surface temperature is smaller in the former case than in the latter case. (iii) In the case of the local sea surface temperature at the places where the effect of the sea surface temperature upon the air temperature is great the effect of the air temperature upon the sea surface temperature is small. Further we proceeded to the investigation whether the parallel cases and opposit cases occur quite at random with the probability of the each occurrence respectively in the both cases of the effect of the sea surface temperature upon the air temperature and that of the air temperature upon the sea surface temperature. It results that in the former case the parallel cases and opposite cases occur nearly at random and in the latter case the both occurrences have the tendency to repeat a little.
Since Stevenson has found that there is the variation of the wind, between the_mast at the height of 15metres and the ground, there are many researches done by various authors such as Douglas, Archbald, N. Shaw, C. J. D. Cave, G. Hellman, Chapman and so on. Geiger adopts as the equation for the vertical variations where υ is the velocity of the wind at a height of h metres and υ1 is the velocity at some fixed height. The value of α is different for the above mentioned writers by reason of a different condition of an environment and height interval observed, and it changes diurnally, as O. G. Sulton says, by the turbulent condition of air. But, if we use a diurnal mean value of α, a series of α closely groups about a mean, strictly speaking, however, it deviates more or less from the mean through the year. But, in Tokyo, the equation for the vertical variation of wind can be shown roughly as follows. where υ0, υ are the velocity of the wind at heights of h0, h metres respectively, in this case h0 is 9.3 metres.
Chaque été, depuis trois ans déjà l'observatoire météorologique central a pu faire connaitre d'avance les temps orageux à ceux qui s'occupent d'industries chargées de fournir les courants électriques. Cela a eu pour résultat de diminuer les pertes causées par l'interruption des courants électriques. Nous donnons ici le résumé de ce que comporte cette prévision dont l'utilisation sera traitée dans la 2ème partie. The electric power consumed in the districts of Tokyo and Yokohama amounts, at present, to 620, 000 K. W. at maximum. The greater part of this power is obtained through hydroelectric plants, transmitted by long transmission lines passing through localities where thunder-storms are frequent especially during the summer season, resulting in service interruptions frequently. The Tokyo Electric Light Co. and several other companies, each supplying electricity in the above two cities and neighbouring districts, cooperated with the Central Meteorological Observatory in observing and reporting of thunder clouds and thunder-storms in these districts, and on receiving warnings, they carried out appropriate measures, thus having minimized the damages caused by lightning and having reduced the extent of its influence, resulting in a remarkably improved service. The paper gives an outline on the above subjects. In carrying out the plan, linemen along the transmission lines and operators in generating stations and substations executed the observation of thunderstorms, and reports were quickly telephoned, through the load dispatcher, to the Central Meteorological Observatory. The Central Meteorological Observatory, in turn, judging from these reports and other meteorological conditions, issued warnings for thunder-storm as to its intensity, the direction of travel, etc. By doing so, not only the service of electricity supply has been considerably improved, but, the local characteristic of thunder-storms was cleared up, and consequently we have obtained valuable data for maintaining the existing installations and constructing new transmission lines or telephone circuits.