Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 17, Issue 5
Displaying 1-6 of 6 articles from this issue
  • M. Abe
    1939 Volume 17 Issue 5 Pages 163-181
    Published: May 05, 1939
    Released on J-STAGE: February 05, 2009
    For the purpose of showing the movement of cloud, I have classified the cloud forms of Mt. Fuji in three types, for convenience sake, as Moving type, Windward type and Leeward type. Here, I classify the clouds again into 20 types as follows under the necessity of dealing with many kind of cloud forms.
    Moving type, Obstacle type, Counter current type.
    Ascending type, Descending type, Stationary type, Rotary type.
    Segmental obstacle type, (S O type)
    Segmental counter current type, (S C type)
    Segmental ascending type, (S A type)
    Segmental descending type, (S D type)
    Segmental rotary type, (S R type)
    Ascending obstacle type, (A O type)
    Ascending counter current type, (A C type)
    Descending obstacle type, (D O type)
    Decending counter current type, (D C type)
    Segmental ascending obstacle type, (S A O type)
    Segmental ascending connter current type, (S A C type)
    Segmental descending obstacle type. (S D O type)
    Segmental descending counter current type, (S D C type).
    Download PDF (1140K)
  • K. Takahasi
    1939 Volume 17 Issue 5 Pages 181-191
    Published: May 05, 1939
    Released on J-STAGE: February 05, 2009
    The wind gustiness has been disregarded at the calculation of wind pressure upon the construction, however, its effect is never negligible but it is the very important part of the wind presure. In this paper, the motion of a simple pendulum exposed to the natural wind was discussed as a model of a construction and it was found that the wind pressure due to the wind gustiness was very large and was about 3 times that due to mean wind. Next, the effective wind velocity, that is to say, wind velocity of laminar flow which will deform the construction in same magnitude with the natural wind, was defined. The effiective wind velocity is the function of mean wind velocity and the nature of the construction, and it was found that it was about 2 times of wind velocity which was recorded at the meteorological observatory. Thus, the maximum wind pressure is calculated by usual wind pressure formula by replacing effective value in wind velocity. Further, the distribution of maximum wind velocity in Japan was researched, and it was cleared that the maximum wind velocity was affected greatly by the topography.
    Download PDF (641K)
  • K. Terada
    1939 Volume 17 Issue 5 Pages 191-198
    Published: May 05, 1939
    Released on J-STAGE: February 05, 2009
    In this paper the earth's crust is considered to be consisted from m's concentric shells (including non-conducting shells) each of which is of uniform nature as to the electromagnetic state. This earth's crust is enclosed by a non-conducting medium, which substantially contains our atmosphere. The shells are bounded at the radii ξ_??_α (_??_=1, 2, … m; α being the radius of the earth).
    It is assumed that the magnetic potential is expressed by spherical harmonic series as is given by (1) and (2) in the Japanese text. From the boundary conditions we obtain the relations (8), (9) and (10).
    For the numerical calculation it is very troublesome to follow the abóve expressions. Now we wish to adopt the series of rather rapid convergency. For this purpose we must discuss the expression Rm. at first. For the small value of |kr| we use the formula (13) and for large value of |kr| we use (14).
    The numerical values of |kr| for various xμ and modes of variations are tabulated in Tables 1 and 2, showing that |kr| is very large for the variation of rapid nature and for large value of xμ and vice versa.
    When |kr| is very small the corresponding variation is of very long duration which shows us the lacking of suitable data to treat such a long periodic variation, hence we will confine ourselves to the cases of large value of |kr| only.
    In the periodic variation we will adopt the relations (18) for the calculation. If we consider rather rapid variation the mathematical expression becomes very simple as we see from (22).
    At any rate at the outermost boundary we have the relation (26). If |kr| is larger than 100 or for the variation of period shorter than about 1 hour, this expression is reduced to (27). In this case the ratio of the vertical component of the magnetic force due to the internal origin to that due to the external origin becomes (28), showing that the vertical component due to the internal origin is reversed its direction to that due to the external origin and their absolute values are generally of the same magnitude. In other words, in rather rapid periodic variation the record of the vertical force does not show any appreciable variation. The similar record is frequently obtained for the so-called Dellinger effect-this point will be discussed in the future paper.
    If |kr| is not so large we must start from (26) and S1(1) is to be transformed by (30). Here γ_??_is calculated as (31). This expression shows an important conclusion:
    If there is at least a layer of sufficient thickness in the earth's crust the electromagnetic induction does not practically penetrate through this layer. This nature depends upon the period and the product of conductivity and permeability. The criterion for these quantities are expressed by the relation (32).
    On the contrary, if we consider the aperiodic variation we can not find any convenient relation for the penetration of the electromagnetic induction and hence we must follow very troublesome calculation for the practical problem of the aperiodic variation.
    Download PDF (374K)
  • N. Yamada
    1939 Volume 17 Issue 5 Pages 198-202
    Published: May 05, 1939
    Released on J-STAGE: February 05, 2009
    In the present paper the author investigated theoretically the Okada's law, concerning the relative motion of the high and low atmospheric pressure, considering that they are the combination of the vortex and the source or sink.
    Download PDF (331K)
  • K. Otubo
    1939 Volume 17 Issue 5 Pages 202-206
    Published: May 05, 1939
    Released on J-STAGE: February 05, 2009
    When a typhoon appears over sea to South of Ryukyu Islands, the change in the thunderstorm activity in Western Japan occurs. In this paper the present author studied the relationship between the thunderstorm activity in Kyusyu and typhoons which attacked Kyusyu or its neighbourhood during the period June-September in 1935-1938.
    The paths of the typhoons studied are shown in Fig 1. The results are:-
    1) When the typhoon enters into the China Eastern Sea, thunderstorm occurs in some part of Kyusyu.
    2) No thunderstorm occurs when the typhoon moves to NE-ward in the sea to East of Ryukyu Islands.
    3) When the typhoon moves through Kyusyu, thunderstorm occurs in front of the typhoon a few days before.
    Severe thunderstorm was experienced in the east quadrant of the typhoon, July 25 1937. This thunderstorm advanced to northward as the centre of the typhoon moved to the North and is considered as the warm front type.
    Download PDF (439K)
  • 1939 Volume 17 Issue 5 Pages 208
    Published: 1939
    Released on J-STAGE: February 05, 2009
    Download PDF (795K)