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Volume 30, Issue 10
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Seitaro Suzuki1952 Volume 30 Issue 10 Pages 305-312
Published: 1952
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESSA secondary anticylone appears invariably over a lofty mountainous district when a large continental or oceanic high stretches out towards that district, while a typhoon splits into 2 parts, when it crosses over a mountain range. In this paper, these facts are illustrated by referring to isobaric distorsions in various weather maps and they are possibly, explained by three theories, i. e. 1. static theory, 2. dynamic theory, 3. frictional theory.
However, the dynamic action is too feeble to exert any noteworthy influence upon the typhoon. And the friction is also incompetent to account for the anticyclonic emergence over high mountains, though it may explain the decline of typhoon on land.View full abstractDownload PDF (1177K) -
K. Uwai1952 Volume 30 Issue 10 Pages 313-328
Published: 1952
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESSUsing the surface autographic records and aerological data, the author analyzed synoptically an abnormaly developed cyclone over the sea south of Kamt_??_hatka in the second decade of January 1950, with reference to the mechanism of development of cyclone, the movement of cold dome, the outburst of NW monsoon in winter, the vertical structure of cyclone and deep cold trough and the manner of appearance of front or squall line on autographic records. The main results obtained are as follows:
(1) This cyclone is accompanied by a marked tropopause low independently of a deep cold trough at first, and so the existence of large downward motion can be assumed at upper layers above the cyclone center before the development of cyclone. The vertical structure of this cyclone is shown in Fig. 11 (it is the same as shown by Palmén except the uppermost layer) and we can show that the necessary conditions for development of cyclone are the large magnitude of mass divergence at middle layer and the downward motion of lower tropopause or layer aloft. But it seems that the latter condition played the main part for deepening of this cyclone.
(2) A marked animate growth of cyclone due to the amalgamation of isalobaric lows, by a deep cold trough advancing after cyclone, and the cyclone itself was performed and then discontinuous rapid deepening was done.
(3) Then the tropopause low accompanied by cyclone separated from the lower cyclone and at this time the deepening of cyclone ceased. Afterward the amalgamation of both lows was done again and then the cyclone reached its maximum development. Therefore we can know the importance of tropopause low for deepening of cyclone.
(4) The NW monsoon comes to weaken when the depth of cold dome has decreased to almost 700 mb and the change of depth has become small.
(5) The autographic records by passage of the cold front and prefrontal squall line are shown in Figs. 3, 4 and 5. The prefrontal squall line is accompanied by the pressure jump and that is the same as shown by Moris Tepper in 1950 except the temperature rise due to adiabatic compression of the layer under the inversion level by sudden pressure rise. After the passage of surface cold front, the marked stepwise change of weather elements as shown in the figures appeared. This will be due to the instantaneous downward motion in cold dome.View full abstractDownload PDF (991K) -
Yoshimitsu Ogura1952 Volume 30 Issue 10 Pages 329-342
Published: 1952
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESSThe equation, which represents the variation of wind with height in a nonadiabatic atmosphere in terms of the heat flux, Reynolds' stress and the roughness parameter, is theoretically derived under the following three assumptions: (i) energy supplied from the mean flow to the turbulence due to the wind shear is balanced both by the dissipated energy due to the molecular viscosity and by the work done against the gravity; (ii) the life time of the largest turbulent element in a non-adiabatic atmosphere is just the same as that in an adiabatic atmosphere; (iii) the vertical eddy flux of a property (momentum, heat or vapour) is independent of the height.
The theoretical results obtained here are compared with Deacon's observational ones, and they are in good accordance. Moreover, the different points of our result from other authors' theoretical ones are discussed, the important role of the energy dissipation by molecula motion being emphasized.View full abstractDownload PDF (696K) -
S. Sakuraba1952 Volume 30 Issue 10 Pages 342-344
Published: 1952
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESSDownload PDF (153K)
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