Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 18, Issue 4
Displaying 1-6 of 6 articles from this issue
1940 Volume 18 Issue 4 Pages 117-125
Published: 1940
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
Zur Russschreibung, des Galitzin-Seismometers versuchten wir eine neue Methode, sogenannte “Flüssigkeitsresistant-Potentiometrische Methode”, in Verbindung mit einem Zweistufenverstärker. Als Regis trierinstrument dient ein selbstschreibendes Galvanometer, dessen Empfind_??_ichkeit etwa 10-5 Amp/mm ist. Die Vergrösserung dieses neu_??_n Seismometers ist 500-1000 fach, und die Eigenperiode im Dauerbetrieb ist innerhalb der Grenzen von 155-205 eingestellt. Die zwei Seismogramme, die mit denen von Wiechert-Seismometer vergleicht wurden, zeigten tatsächlich, dass dieses neue Seismometer als ein Fernbebenmesser sehr vorzüglich ist.
• K. Takahasi
1940 Volume 18 Issue 4 Pages 125-130
Published: 1940
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
The distribution of various meteorological elements in a typhoon was investigated, assuming that the typhoon is symmetric about its center. The results obtained are summarized as follows.
1) The distribution of precipitation per unit time is given by the following empirical formula where m0 and rm are constants of the typhoon and r is the distance from the center.
2) The intensity of precipitation depends on that of typhoon, and m0 in the above equation increases linearly with the increase of the depth of typhoon. If the depth of a typhoon is 730mm, m0 is of the order of magnitude 100mm/day.
3) If φ(ξ) is the total amount of precipitation at a point, ξ being the smallest distance from the center during the traveling of typhoon, the distribution of precipitation is calculated by where the velocity of typhoon is v.
4) The distribution of relative humidity H is given by the following empirical formula where rn is a constant which is about 200km.
5) The mixing ratio of water vapour is almost constant within the area of typhoon and increases with the increase of the intensity of typhoon.
6) The potential temperature is constant within the area of typhoon by my first approximation.
7) The maximum of wind velocity in the area of typhoon is a function of the intensity of typhoon, and the following empirical formula holds good approximately: Vmax(m/sec)=5.1√ΔP0
8) The diameter of the largest closed isobar of typhoon is given by D(111km unit)=0.33ΔP0
9) The radius of the cloud area of typhoon is given approximately by rc(km)=18×ΔP0
10) The radius of the rain area of typhoon depends on the intensity of typhoon and it is given approximately by rp(km)=8×ΔP0
11) From the above results it is concluded that the adiabatic change holds, at least by my first approximation, within the area of typhoon.
• S. Todyo
1940 Volume 18 Issue 4 Pages 130-137
Published: 1940
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
At present there are two dominant theories for the mechanism of falling rain. One is the polar front theory set forth by the Norwegian school, which considers the rain to occur along a front. In this theory the area of precipitation extends with the movement of the front, and so it may be concluded that the lower circulation of the atmosphere is primarily important for the mechanism of falling rain. The other is the “Steuerung” theory developed by H. v. Ficker and followed by the Central-European school, in which the area of rainfall is mostly influenced by upper air circulations.
The present paper investigates these two typical examples of rainfall in the Far East. According to the report of the Shanghai Observatory, the first example of rainfall was observed on the afternoon of November 8, 1939 in the interior of a modified Tm air mass. This rain area started from somewhere near Formosa and extended towards the NE-direction, guided by upper air currents, as it was seen from the estimated 3000m isobars. The center of isallobaric low (the time interval was put as 24 hours) accompanying this rainfall also took the same direction. After some more detailed examinations, the essential cause of this rainfall may be reduced to the vertical instability of the air mass itself. Thus the “Steuerung” theory is important for this rainfall.
The second example of rainfall occurred in the midnight of the same day, which was caused by the conspicuous cold front due to the outbreak of a modified Pc air mass from the Siberian High. The cold front moved towards the SE-direction across the 3000m isobars. Thus the second rainfall is well explained by the polar front theory, as is ordinarily the case in the Far East.
• Studies on the Relations between the Yield of lmportant Crops and the Weather Factors in Japan. No.1
Y. Daigo
1940 Volume 18 Issue 4 Pages 137-144
Published: 1940
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
In this paper the coefficients of correlation between the yield of aquatic ricecrop and the weather factors (monthly mean of air temperature, monthly amount of rainfall, and monthly total hours of sunshine) during the period from 1902 to 1937 were computed by the following formula for each prefecture in Japan, each from April to October: where DY represents departure of the yield of ricecrop from the moving mean by the 5 years, and DW that of the weather factors.
The correlation coefficients of the temperature and of the sunshine with the yield are almost positive, while that of the rainfall is mostly negative as shown in Tables 1, 2, 3.
From the above results we see undoubtedly that warm, dry and sunny weather in Japan is favourable for rice-crop. Relations between the yield and the weather factors in the northern districts of Japan are slightly different from those in the southern districts.
In the northern districts the correlations between the yield and the weather factors are generally highest during the ear-appearing period. This indicates that the summer air temperature in the northern districts has direct influence upon the yield of rice-crop as a limiting factor.
In the southern districts, the correlations between the yield and the weather factors are lower than in the northern districts and the yield of rice-crop is largely dependent on the temperature during the transplanting period and on the sunshine during the period from flowering to fruiting, and then the rainfall has not so much influence as we have expected.