Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 18 , Issue 6
Showing 1-7 articles out of 7 articles from the selected issue
  • K. Takahasi
    1940 Volume 18 Issue 6 Pages 177-190
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    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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  • H. Matui
    1940 Volume 18 Issue 6 Pages 190-194
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    1. Calcium: The method of determining calcium in water is based on the permanganatometry of its oxalate. In this method, the oxalate of calcium is treated with dilute sulphuric acid and the liberated oxalic acid is then titrated with the standard solution of potassium permanganate. The author studied the influence of the coexistence of magnesium with calcium, since magnesium is the most common contaminating substance in this method. The experimental result shows that the small content of magnesium (<10mg Mg/L) has no appreciable influence upon the determination of calcium.
    2. Magnesium: Magnesium is determined by the titration of its quinolate, proposed by Berg. Magnesium is precipitated in an ammoniacal medium with the alcoholic solution of oxine (8-hydro-xyquinolin). The precipitate is filtered and then dissolved with a little hydrochloric acid, and it is titrated with the standard solution of potassium bromate, a few drops of indigo-carmin or methyl red being added as indicator.
    Magnesium can be almost completely separated from calcium with oxine. As for the magnesium determination of water containing less than 20mg of calcium per litre, this method appears to be quite useful, and also it seems to be suitable for the routine work in limnology.
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  • S. Syono
    1940 Volume 18 Issue 6 Pages 195-197
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    In the present short note, we investigate the force acting on a vortex in a non-uniform stream of a viscous fluid. According to Bernoulli's theorem the pressure at a point in a certain stream-line becomes larger where the stream-lines converge. Hence, a vortex standing perpendicularly to the stream is forced to the side where the stream-lines converge. By the same reason two vortices revolving in the same sense repulse each other and vice versa. But actually, we observe facts that contradict with the above law, e.g. two circular cylinders revolving in the same sense attract each other if the viscosity is large and two vortices in water attract each other and amalgamate. The latter fact is called Okada's law in the meteorological circle of Japan. In order to remove the contradiction, we give here a note. Assuming a two-dimensional stationary state and integrating the equation of motion of an incompressible viscous fluid along a stream-line, we get: where the notations are those commonly used and C is a constant. The integral-term becomes effective, when μ becomes sufficiently large. Investigating this term, we obtain the result that does not contradict with the fact.
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  • S. Honma
    1940 Volume 18 Issue 6 Pages 197-201
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    For a theoretical treatment of slow motions of the air near the surface of the ground, it is desirable to stand on the basis of the equations representing the motion of viscous, compressible fluid and the convection equilibrium of heat. But by using the latter equations, it is difficult to reach appropriate solutions, excepting cases where liquid is concerned; the equation of state of liquid is expressed in a comparatively simple form. To get rid of this difficulty, we introduced the equation of polytropic change and obtained examples in which a stream-line was parted into two branches, which joined again each other, enclosing eddy flows, without assumption of any discontinuous surface in the field of motion.
    The equations (1) represent the conditions of the static equilibrium, (2), (3) and (4) are the equations of motion, and (5) is the equation of state of the atmosphere, where x and z are horizontal and vertical co-ordinates, (u, w) velocity compo-nents, p0+p, T0+T and ρ0+ρ pressure, temperature and density respectively. The suffix 0 is attached to the quantity representing the static equilib-rium. (6) expresses polytropic condition. Under the assumption of the isothermal atmosphere, a particular solution with a general current U may be given by (19) and (20), where λ is determined by (16) or (17).
    Fig. 3 shows an illustation of a family of stream-lines schematically. When stream-lines are compelled to run upward or downward, an eddy flow may appear at their front or back respec-tively. In the same figure we may find an example of topographic effect on winds under conditions somewhat different from Pockels' case (F. Pockets: Met. ZS. 1901).
    If U is comparatively small, there appears a circulation in the air just above the trough of stream-lines, bearing some resemblance to the eddy at the head of a squall (Fig. 5). Finally, we examined shortly the case of progressing obstacles and proved that generally there must be an infinite number of horizontal, nodal lines in the air, but the general characters of circumstances were not essentially altered.
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  • K. Isiwara
    1940 Volume 18 Issue 6 Pages 201-206
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    The author of the present paper investigated the monsoon-precipitation in Kanazawa and the following results were obtained.
    (1) The monsoon-precipitation of showery nature occurs in Kanazawa when the Siberian high pressure develops.
    (2) The precipitation is expected when the air temperature at Gensan is lower than that over the Tusima Stream, and not expected when it is higher. Generally speaking, the amount of precipitation is greater when the difference of temperature at both places is larger.
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  • K. Siomi, S. Yosida
    1940 Volume 18 Issue 6 Pages 206-210
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    In order to examine the changes of the velocity of evaporation from a free water surface produced by wind, experiments on evaporation were made under various wind velocities of 0-10m per sec in a wind tunnel. To compare the results with Tra_??_ert's evaporation formals, QP/T (E-e) (1-0.0142t) was calculated from the evaporation velocity Q, where P is the atmospheric pressure, T absolute temperature of air. E-e saturation difference of air, t temperature of air in °C and 1-0.014t a correction by which Trabert's evaporation formula Q=T/CP(E-e)√W should be multiplied, where IV is the wind velocity, according to the experiment of Okazaki and others.
    The results are as follows.
    (i) The term √W should be substituted by √W-C, where C is a constant of 0.3_??_0.5m per sec.
    (ii) At large wind velocities of 6-7m per sec or more, the quanity becomes constant, which does not depend on the wind velocity.
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  • 1940 Volume 18 Issue 6 Pages 212
    Published: 1940
    Released: February 05, 2009
    JOURNALS FREE ACCESS
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