Journal of the Meteorological Society of Japan. Ser. II
Online ISSN : 2186-9057
Print ISSN : 0026-1165
ISSN-L : 0026-1165
Volume 20, Issue 7
Displaying 1-4 of 4 articles from this issue
• S. Syono
1942 Volume 20 Issue 7 Pages 215-226
Published: 1942
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
Chapter 1. Polytropic potential temperature.
We introduce a new quantity e.g. polytropic potential temperature, _??_, defined by the following formula:
When an air-parcel ascends in polytropic atmosphere of class k and then the class of polytropic change of state is k', the rate of decreasing temperature of the air-parcel is equal or not with the lapse-rate of the atmosphere according as k', is equal or not with k'. The difference of temperature of the atmosphere and the ascending air parcel at 10km amounts to 8°C and is no more negligible. In our atmosphere the lapserate of temperature is about-0.5°C/100m and this correspond to that of polytropic atmosphere of class . about 7/6. But, this fact does not mean that the. change of state in the atmosphere is polytropic change of class 7/6, therefore, generally, we can not use the polytropic constant 7/6 as that of change of state. However, we may use the constant of change of state in ascending region.
Chapter 2. Relation between lapserates of temperature and potential temperature.
We gave a remark on the relation between two lapse-rates of temperature and potential temperature and a numerical table.
Chapter 3. Vertical motion and pseudo-polytropic constant.
When an air-parcel ascends in the atmosphere, its volume expands necessarily and does work to the atmosphere. In this case, if heat-excharge of amount Kin unit time takes place, the pseudopolytropic constant k is given by where cp and cv are specific heats at constant pressure and constant volume respectively. R, g, υ denotes gas-constant, gravity constant and velocity respectively.
Chapter 4. Horizontal motion and pseudo-adiabatic constant.
When an air-parcel moves horizontally under the same condition as in chapter 3, the pseudopolytropic constant is given by where Vn and V3 denotes velocity components perpendicular and parallel to the isobar and υ is viscosity-coefficient.
• Y. Kawabata, T. Ayuda
1942 Volume 20 Issue 7 Pages 226-238
Published: 1942
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
In the first part of this paper, some geodesic reductions were made upon the deflections of the vertical which were observed in Japan, and then, in the second part, the. corrections due to the topography were applied, assuming that the mountain or the sea exert as an excess or defect of mass respectively.
The result of this calculation show that the plumb lines are generally attracted toward the Pacific Ocean (the arows in Fig. 3 are drawn in the opposite sence of the attraction). This fact show that the theory of Isostasy holds for Japan also, because the Pacific Ocean is relatively deeper compared with that of Japan sea. Lastly, the depth of isostatic compensation was calculated by the method of, trial and error assuming the various depth of compensation, and it was determined to be about 120km. below the mean sea level (see Fig. 5).
• M. Hanazima
1942 Volume 20 Issue 7 Pages 238-251
Published: 1942
Released on J-STAGE: February 05, 2009
JOURNAL FREE ACCESS
The more comprehensive classification of plane type crystal of snow is proposed and the external conditions favourable for the development of each of the types are studied. The experiments were carried out, as the previous work, with the room temperature ranging between -20°C and -30°C in the cold chamber of the Low Temperature Laboratory. The results are given In Ta-Tw diagram and it was found that, besides the rate of supply of water vapour, the temperature of the air where the crystal is made has a strong influence on the mode of cr stat development.