Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 19 , Issue 1
Showing 1-6 articles out of 6 articles from the selected issue
  • G. Yamamoto
    1941 Volume 19 Issue 1 Pages 1-5
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    This apparatus is designed to measure the polarity and the strength of the electric field in the thunderclouds. It utilizes, like Simpson and Scrase's apparatus, the point discharge current in the antenna, but the method of utilization is entirely different from their method. In our apparatus the condenser is charged by the point discharge current, and it is discharged through neon tubes. By counting the number of discharges we can know the strength of the field. To find out the sign of the electric field, we make use of one of the properties of the neon tube, that is, the polarity of the neon tube. For this purpose, neon tubes having considerable polarity (about 20-40V) is specially made. Finally the measuring circuit is introduced in the grid circuit of short wave oscillator which emits waves of about 15 MC, so that by receiving the wave we can measure the field of the thunderclouds immediately at the ground station. The weight of this oscillator is about 60g with battery, and when fully equipped with antenna, parachute, etc., it becomes about 900g.
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  • K. Maeda, T. Kohno
    1941 Volume 19 Issue 1 Pages 5-8
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    Since the reflection of electromagnetic waves from the lower atmosphere, including troposphere, has been first reported by Friend and Colwell of America in 1937, experiments were developed also in England and in Japan. This low reflecting layer is called C-layer and its height is estimated to range from about 30km to 1km.
    Recently, advanced experiments have been carried out in America, and followings can be predicted as the correlations between C-layer reflections and meteorological conditions.
    (1) When the cold front passes throgh the station observing C-layer, waves are reflected from the lower level, which can be attributed to the plane of discontinuity.
    (2) Waves are reflected from the point, where temperature inversion or marked variation of humidity takes place.
    (3) Scattered echos are reflected from gusty air.
    (4) Some correlations exist between C-layer reflections and thunder clouds.
    Echo patterns and continuous height records, obtained in Japan, are shown in figures 1 and 2.
    It is pointed out that explanation of the mechanism of reflection from C-layer is of future importance from the viewpoint of wave propagation and meteorology. It is hoped that the study of the lower atmosphere is promoted by the intimate cooperation of radio sonde, radio sounding technique and the knowledge of meteorology.
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  • M. Nakahara
    1941 Volume 19 Issue 1 Pages 9-16
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    As the insect phenology, the date of the first and last seen of butterfly (Pieris Rapae, L.) and firefly (Lampyridae), the first and last singing of cicada (Platyplenra Kaempferi F., Meimuna opali-fera Walker.) were selected from the original phenological reports issued monthly in Japanese at the Central Meteorological Observatory in Japan.
    We calculated the coefficient of correlation between above mentioned date and the monthly mean temperature, monthly mean of highest temperature and the lowest, the duration of sunshine and the amount of precipitation for each meteorological station observed more than ten years,
    Calculation was shown in Table 1, 2, 3, 4 and the following result was recognized from them.
    The most conspicuous effect was afforded by temperature in the case of the first appearences and singings, while it was not so effective as the amount of precipitation or the duration of sunshine in the last seens and last singings.
    In cicada on the drought of 1939, those was demonstrated by the fact that the date of first, singing was earlier and that of last was later than usual.
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  • S. Syono
    1941 Volume 19 Issue 1 Pages 16-22
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    §3. Relation between Vorticity, Convergence and Horizontal Pressure Field.
    In chapter 2, we discussed the fundamental equation of ψ derived from the equations of motion by cross-differentiation. But strictly speaking the above discussion is not satisfactory, because we can not take Q as a known function. In order to treat the problem satisfactorily, we must assumo both ζ and Q as unknown functions. Indeed, ζ and Q are reciprocal in the rotating earth-atmosphere.
    In the prescnt chapter, we discuss equations: which are derived from the equations of motion. To elucidate only the dynamics of nacsent cyclones, all terms which are squares and products of velocities and their derivatives are neglected. Assuming that the left hand sides of the above cquations represent those of fundamental state and known functions, we discussed relations between f1, f2 and ζ, Q. The main results are as follows:
    (1) If eddy viscosity vanishes and f1 and f2 are timely constant, ζ and Q depend only on f1 and f2 respectively.
    (2) If f1 and f2 vanish. ζ and Q osciilate and their amplitudes damp exponentially in our atmosphere.
    (3) If f1 and f2 are variable, ζ and Q depend both on f1 and f2. Further, when the variation of f1 and f2 are comparable with one day, the effects of f1 and f2 on ζ and Q are comparable. The effect of viscosity on this point is small compared with that of variablity of f1 and f2 in our atmosphere.
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  • Y. Daigo
    1941 Volume 19 Issue 1 Pages 22-27
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    The coefficients of correlation between the yield of naked barley and the weather factors (Monthly mean temperature, monthly amount of rainfall and monthly total hours of sunshine) have been calculated by the method previously reported in this magazine, for each prefecture in Japan, each month during the cultivating time.
    The correlation coefficients calculated are shown in tables 1, 2, 3.
    From the correlation coefficients we see clearly that the weather at the early stage of growth and from flowering to ripening time has most important influence upon the yield of naked barley and it is favourable for the naked barley culture when the weather is rainless, sunny at the above each time.
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  • Y. Daigo
    1941 Volume 19 Issue 1 Pages 28-33
    Published: January 05, 1941
    Released: February 05, 2009
    JOURNALS FREE ACCESS
    The coefficients of correlation between the yield of barley and the weather factors (Monthly mean temperature, monthly amount of rainfall and monthly total hours of sunshine) have been calculated by the method previously reported in this magazine, for each prefecture in Japan, in each month during the cultivating time.
    The correlating coefficients calculated are shown in table 1, 2, 3. and the main results are as follows:
    1. The correlation coefficients between the yield of barley and rainfall are mostly negative in each month during the cultivating time, and they show that the rainfall has most important influence upon the yield than the other weather factors. The most close correlation with the yield and rainfall is found at the winter time in Tohoku-and Hokuriku districts, at the early time of growth in Kinki-and Tyugoku districts and at the ear appearing time in Kanto districts. It is noteworthy in this research that the correlation at harvest time is not so close in each prefecture that we expected.
    2. The correlation between the yield of barley and sunshine is mostly positive. The cultivating time in which the yield and sunshine has most close correlation, is not similar for the prefectures.
    The close correlation between the yield and sunshine appears at an early stage of growth as well as at the time of ripening to harvest in Kanto districts, while it appears only at the time of ripening to harvest in Tokai, Sikoku and Kyusyu districts.
    3. The correlation between the yield of barley and temperature is not so close as that with the above weather factors, and the relation in the northern part of Japan differs somewhat from that in the southern districts.
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