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Volume 8 (1957 - 1958･･･
- Issue 4 Pages 245-
- Issue 3 Pages 171-
- Issue 2 Pages 109-
- Issue 1 Pages 1-
Volume 8, Issue 1
Displaying 1-9 of 9 articles from this issue
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K. Gambo1957 Volume 8 Issue 1 Pages 1-24
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSIn the first part of this paper, the orders in magnitude of each term in the vorticity equation, the divergence equation and the equation of the vertical p-velocity are discussed as functions of the Rossby-number. As the first approximation of such equations, the quasi-geostrophic approximation is used. The second approximation is also discussed in connection with the balance equation.
In this case it is to be emphasized that the most important problem is how to filter out the meteorologically unimportant “ noise ” of disturbances. In the second part of this paper, the effect of topography on the height change with time in the lower atmosphere is considered from the point of view of scale-quantity. The vertical p-velocity due to the effect of topography is divided into two parts: one is the largescale pattern which contributes to the height change with time in the lower atmosphere and the other is the small-scale pattern which contributes only to the precipitation without changing the pressure pattern on the earth's surface.
In the last part of this paper, these theoretical results are compared in good agreements with the observed pressure change with time on the earth's surface.View full abstractDownload PDF (2635K) -
M. Magata1957 Volume 8 Issue 1 Pages 25-38
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSIn order to discuss the general character of the perturbations of the westerlies produced by the mountains such as the Himalayas and the Rockies, we solve the stationary vorticity equation for the equivalent-barotropic level, taking into account topographical factors. It is shown that owing to the intensity of the general current, there are critical cases in which a single jet stream or two branches of it appear and these can be regarded as characterizing the normal state at the 500-mb level in January or June respectively. Especially the persistence of a ridge over the Sea of Okhotsk in the Baiu season, is thought to be produced in connection with the Himalayas. The effect of shear of the general current and friction upon the flow pattern are also discussed.View full abstractDownload PDF (1493K) -
Akio Arakawa1957 Volume 8 Issue 1 Pages 39-54
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSAssuming that the longitudi n al phase of each wave component of disturbance takes random values, relations which hold among mean eddy transports have been found in the case of stationary mean. In the middle latitudes, where the horizontal eddy transport of heat is northward, the vertical eddy transport of heat is expected to be upward from one of these relations, causing the transformation from eddy potential energy to eddy kinetic energy. As to the vertical eddy transport of momentum, it seems to be upward not only in low latitudes but also in middle latitudes. This suggests, from the balance requirement of angular momentum, that the downward transport of angular momentum by the frictional effects, in addition to the indirect meridional circulation, cannot be so small in magnitude as hitherto been considered.
Combining these relations among eddy transports with the equations for the balance of angular momentum and thermal energy, it has been found possible to express the relation between the distributions of mean zonal flow and heat source. Detailed discussions for this expression are left for future studies, but the observed relation between them can be thus explained at least qualitatively.View full abstractDownload PDF (2342K) -
Y. Masuda1957 Volume 8 Issue 1 Pages 55-64
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSIn order to avoid the truncation errors near the typhoon center, which arise in the course of numerical computation, and to obtain the stream function in the vicinity of typhoon precisely, the balance equation is separated into two parts; the one is corresponding to the circular symmetric field and the other, to the residual field. The stream function corresponding to the circular symmetric field is easily obtained by the gradient wind equation. After the condition for existence of solutions of the balance equation corresponding to the residual field is examined, the point relaxation procedure to solve this equation is proposed. An example of this solving method, applying to the typhoon Harriet, is presented also.View full abstractDownload PDF (1336K) -
S. Kubota1957 Volume 8 Issue 1 Pages 65-80
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSWe have proposed the m e thod of integration of the vorticity equation, called the quasi-double-Fourier method, or the method of one-dimensional Fourier series with one-dimensional relaxation.
In this paper, some technical improvements made thereafter are presented namely the enlargement of forecasting area, the increase of wave numbers adopted in calculation, the employment of inverse matrices in relaxation, and the smoothing process.View full abstractDownload PDF (2145K) -
I. Imai1957 Volume 8 Issue 1 Pages 81-97
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSResults of radar observations of thunderstorms that occurred in the western Kanto district on 14 August 1956 are described. It was found that in general the isobronts preceded radar echoes by about 20 km. Detailed observations of an anvil cloud which drifted eastward from the mother thunderstorm were made with PHI scope. Ice particles or snowflakes falling from the anvil top formed trail patterns and a well-defined bright band as in the case of warm-front type precipitation. Downward protuberances or “ stalactites ”, probably caused by the evaporative cooling of snowflakes falling into dry air, were found at the base of the anvil. They extended downward across the bright band and formed streaking rain patterns under the band. Judging from the slope and the movement of rain patterns and the observed variation of raindrop size-distribution with time, the generating sources of the rain patterns may be ascribed to the stalactites. A lowering of the bright band, of about 200 to 300 m, was also found at its leading edge.View full abstractDownload PDF (7267K) -
M. Sanukii, N. Tsuda1957 Volume 8 Issue 1 Pages 98-101
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSTo visualize the velocity distribution of the flow over an anemometer tower, tank test is conducted for cylinders resting on a flat plane, thus representing the actual arrangement. It is concluded from the results that the usual installation is far from satisfactory, causing serious errors at times. A remedy is proposed and tested. It is also suitable to weather stations suffering from snow deposit on the anemometer.View full abstractDownload PDF (1580K) -
M. Kobayashi, N. Kitagawa1957 Volume 8 Issue 1 Pages 102-106
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSIn electrical study of lightning discharge, it is essential to record faithfully the field-change clue to a lightning discharge during the whole duration. Fdr this purpose the authors used simultaneously two different methods of observation, i. e. an electrostatic fluxmeter and an amplifier oscillograph. The slower field-change having longer duration than 1 m-sec up to the static field was recorded by an electrostatic fluxmeter, while the faster change having shorter duration than 1 m-sec by an amplifier oscillograph. Operating these apparatuses we can record correctly all the field-changes, whether slow or fast, due to various processes in the lightning discharge, and time of several microseconds can be resolved.View full abstractDownload PDF (1123K) -
K. Kamiyama, I. Nashimoto, H. Suda, Y. Yamaguchi, T. Kubota1957 Volume 8 Issue 1 Pages 107-108
Published: August 31, 1957
Released on J-STAGE: December 11, 2012
JOURNAL FREE ACCESSDownload PDF (272K)
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