Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 19, Issue 11
Displaying 1-4 of 4 articles from this issue
• S. Syõno
1941 Volume 19 Issue 11 Pages 401-418
Published: November 05, 1941
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
Chapter 8. Discussion about coordinates systems to be used.
In the previous investigation, we have used local Cartesian coordinates for the sake of convenience. But for investigation of very large cyclones or anti-cyclones whose radii are not negligibly small compared with the radius of the earth and which travel over a large distance, spherical polar coordinates are more appropriate than local Cartesian coordinates.
In the present chapter, we discusse l the difference between two sets of the fundamental equations expressed in both coordinates-systems. One of the equations in the Cartesian coordinates has one term 2ωw/a sinθ more than compared with that in the polar coordinates. Since ω is usually of the order of a few tenths of u or v, this term is negligibly small compared with the other one, e. g. 2ωu/a cosθ. It vanishes when w vanishes. Hence when w vanishes or is very small, two equations in the two coordinates-systems are equivalent in physical sense.
Chapter 9. Structure of stationary cyclone.
In the present chapter, we discussed the inclination of the isobaric surface in a revolving storm. One of results obtained is that for the case Vθ=10m/sec, r=100km and φ=30°, the height-difference for 100km horizontal distance is 17m. Further, we obtained a formula that gives the pressure at a point in the vortex embedded in the polytropic atmosphere; i.e.
where P0, T0, γ and K denote pressure and temperature on the earth surface in the polytropic atmosphere, lapse rate in the vortex, respectively. Next, we discussed the relation between the temperature distribution and the wind, and obtained a relation, Further, we discussed the inclination of the surface of constant potential temperature, and obtained following relation:- where θθ and θp are angles of inclination of surface of constant potential temperature and isobaric surface.
Chapter 10. Penetrative horizontal stability in a cyclone.
In the present chapter, we obtained a criterion about horizontal stability in a revolving symmetric storm. The criterion may divided into two parts, i.e. one is statical and thermal one and the other is dynamical one. When the centrifugal accerelation K is constant with respect to r, the horizontalstructure is stable if where _??_ denotes common adiabatic lapse rate in vertical direction, and rice versa. This result is obtained by comparison with the equation of motion in vertical and horizontal directions.
But K is not constant in general. We rediscussed the stability of a air-parcel about virtual horizontal displacement, and obtained fallowing result: Next we give two numerical examples in order to elucidate the criterion:
(i) For the case Vθ=30m/sec, r=100km, _??_=30°, §=9λ,
The above case is that of very strong dynamical stability, so that the temperature increase of 1 degree per 100m is allowed.
(ii) For the case Vθ=20m/sec, r=200km, _??_=45°, ξ=λ,
• Y. Takahasi
1941 Volume 19 Issue 11 Pages 418-425
Published: November 05, 1941
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
The method of the graphical calculation in the case of the one-dimensional conduction of heat in solid was applied to the problem of the two-dimensional conduction of heat in the semiinfinite solid with a cave of rectangular crosssection, the wall of which are insulated, the temperature of the solid being initially zero, and the surface being kept at temperature unity. The calculations are carried out in supposing that the linear flow of heat takes place alternatively in the directions of x and y.
• K. Yakame, T. Hoshino
1941 Volume 19 Issue 11 Pages 425-436
Published: November 05, 1941
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
Four patterns of cup anemometers, the standard type and the others, and three patterns of the pressure tube anemometers were compared in the 1.5m wind tunnel of the Aeronautical Research Institute, Tokyo. And we compared them exposing to natural wind. From these comparisons we confirmed that the indications of the standard cup anemometer and the preassure tube anemometer are pretty good, and found an important point for designing new standard type anemometers which will have better sensitivity and proportionality existing between the indications of the anemometers and the velocity of natural wind.