Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 41 , Issue 6
Showing 1-6 articles out of 6 articles from the selected issue
  • Ryõzaburõ Yamamoto
    1963 Volume 41 Issue 6 Pages 309-316
    Published: December 28, 1963
    Released: October 19, 2007
    Elastoid-gravoid wave in a circular vortex can assume a radially banded feature under some conditions. Combining the factor exp (ikr) expressing pproximately such feature with the factor exp (ilθ) inherent for elastoid-gravoid wave, spiral regions of upward motion can exist, where γ and θ are radius and azimuthal angle, respectively. The wave of small l assumes a radially banded feature only near the center, and the wave of large l does not there.
    Discussions are given about generation of these waves, noticing the concentrated strong upward motion and abrupt change of wind velocity near the center.
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  • E. Inoue
    1963 Volume 41 Issue 6 Pages 317-326
    Published: December 28, 1963
    Released: October 19, 2007
    αTaking the observational evidences of the exponential wind velocity profile within crop canopies into account, the geometrical and dynamical haracteristics of canopy-eddies have been investigated from both theoretical and observational points of view. The length, width and depth of canopy-eddy have been suggested to be constant with height within the canopy layer and to be in proportion to (H-d), where H is the crop height and d the zero-plane displacement derived from the logarithmic velocity profile above canopies.
    Velocities in three directions of canopy-eddy are also suggested to decrease downward following the exponential form of exp {-α(1-Z/H)}, where Z is the height measured from the ground surface beneath the crop height plane.
    The connections between the exponential and the logarithmic velocity profiles within and above crop canopies and those between the canopy-eddy and the HONAMI-eddy, which causes waving-plants phenomena (HONAMI), are specifically dealt with.
    Applying the inertial-subrange theory of turbulence to canopy-eddies a method of evaluating the vertical transfer coefficient within crop canopies is presented and tested with earlier observations.
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  • Tsutomu Takahashi
    1963 Volume 41 Issue 6 Pages 327-336
    Published: December 28, 1963
    Released: October 19, 2007
    Chemical composition of snow crystals has been investigated by the analysis of snow samples collected separately according to snow crystal shapes. The chemical elements analysed were Cl, Na, NH4, SO4, Mg, Ca, NO2, Fe and Si. Snow crystals collected were classified into several groups ; columns, rimed or not rimed dendrites, rimed radiating dendrites and graupels, etc. It has been found that the chemical composition shows marked dependence on the shape of snow crystals as follows;
    (1) The concentrations of Na, Cl and NH4 in columnar crystals were lowest among those in all shapes of crystals.
    (2) The concentration of NH4 was highest in dendritic crystals.
    (3) The concentrations of C1 and Na were highest in graupel. The relative concentration of the chemical elements of graupel was close to that of sea water.
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  • R. Sasaki
    1963 Volume 41 Issue 6 Pages 337-347
    Published: December 28, 1963
    Released: October 19, 2007
    Two remarkable groups of precipitation were observed as the typhoon 5907 advanced northward through the central part of Japan. One of these groups was observed in the vicinity of Tsu city west of the typhoon path, showing a heavy rainfall amounting to 95.3mm hr-1. The other group brought about one-third hourly precipitation of the former on the mountainous areas in front of the typhoon. The mechanism of these rainfalls is analyzed using isobaric and isentropic charts, with the following results:
    (1) These rainfalls are qualitatively explainable by use of isentropic analysis, though the observed precipitation does not coincide with a computed one based on the large scale analysis.
    (2) From the observed value of the former precipitation, a small scale disturbance is presumed, which took birth on the westside of the typhoon trajectory owing to an interaction of westerly currents and the typhoon, and the horizontal scale of the disturbance is estimated to be about 50 km. In other words, this is inferred to be a meso-scale disturbance possessing an ascending velocity of 2m sec-1, or an isentropic slope of 1/20.
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  • Kyoiti Takeda
    1963 Volume 41 Issue 6 Pages 348-354
    Published: December 28, 1963
    Released: October 19, 2007
    Applying the equation of turbulent transfer to the heat loss from a human body, an equation is obtained which describes that the heat loss is proportional to the gradient of total heat (enthalpy) . But for practical purposes the heat loss is assumed to be proportional to the difference of total heat, and a transfer coefficient is introduced instead of eddy diffusion coefficient. When it is comfortable, i. e. in spring or autumn, the heat loss is considered to be the normal. An index (=comfort index) Ic is defined as a ratio (heat loss)/(normal heat loss), and also another index (discomfort index) ID is efined as ID=1-Ic. Thus ID will denote the rate of disturbance for the development of normal heat loss. ID will also be used as a climatic index ; thus adopting reasonable values for the total heat, it is found that
    (i) ID>30% corresponds to the climate : without clothes, (ii) 30%>ID>10% : summer clothes,
    (iii) 10%>ID>-10%: spring clothes, (iv) -10%>ID>-30%: winter clothes, (v) -30%>ID: protecting outfit against cold.
    The effect of wind on the index is readily taken into account by assuming the square root law of wind velocity for the coefficient, and it is shown explicitly that the effect is larger in the cooler climate than in the warmer. The difference in the indices due to clothing is also discussed and the relation is proved to be linear. Finally two charts are given, one (Fig. 1 in the text) denoting relations between (dry-bulb) temperature, relative umidity, wet-bulb temperature, enthalpy, discomfort index, and wind velocity, and the other (Fig. 2 in the text) denoting the relation between our index ID and hitherto used index ID'.
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  • Y. Sasyo, H. Tokuue, K. Tsukada
    1963 Volume 41 Issue 6 Pages 355-360
    Published: December 28, 1963
    Released: October 19, 2007
    In order to consider the effect of random walking on the process of coalescence, the blotting paper fragment (2×2cm2) coated with soluble blue is dropped through the rain from about 9 meter height above ground.
    The number of rain droplets collected by the paper fragment increases proportionally to the falling duration of the paper fragment and the spacial concentration of rain droplets, but this number has no relation to the size of rain droplets or the relative velocity of paper fragment with respect to rain droplets.
    The rate of collision is about twice the expected value, which is calculated under the assumption that the paper fragment falls vertically with constant cross-section and average speed.
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