Dyinamic Climatological Consideration on the Alfernation of Winter Weather in the Far Eastern Asia

[摘要] Winter weather in the Far Eastern Asia was studied from various stand point of view and the results are summarized as follows:-(1) The alternation of winter weather in the Far Eastern Asia is quite simple, and a typical distribution of pressure continues for several weeks together. This holds also for climate, and a similar climatic state continues for a long interval during a season.(2) The air temperature as well as weather in Japan are controled by the air temperature in Asiatic continent.(3) The wind velocity of the monsoon is a function of the pressure at the center of North Pasific Low, and the relation between them can be expressed by υ=υ0√770-P, where υ0 is a constant.(4) A typical pressure distribution of winter in the Far Eastern Asis is so called Seiko-Totei (high in the west and low in the east). This is produced by the temperature difference between continent and ocean, and the height of monsoon seems to below, say, a few kilometer. This pressure distribution can be considered as a result of an out flow of cold air from Siberia, and the amount of the out flow of air, calculated assuming that some amount of the energy of monsoon is disipated by the surface friction, agrees with actual observation.(5) The transfer of thermal energy due to the advection was calculated under very simple assumptions. It is found that the temperature of air mass can be considered to be conservative during a day, and the positive correlation of air temperature between the continent and Japan is found.(6) The temperature of air mass in winter is very low, and contains only a small amount of water vapour. Accordingly the precipitation depends greatly on the amount of vapour tension, and it was shown that the increase of vapour tension is important as a precursor of the rainy weather.(7) The amount of precipitation m depends on the pressure p as well as vapour tension and the relation between them is expressed in rough approximation by m=α(770-p) where α is a constant. This relation is proved theoretically by calculating vertical current due to frictional in-flow.(8) Depression is generated often near Taiwan in winter season and it is called as Taiwanbozu. This depression is a typical one in young stage and its structure is investigated, and a mode of the alternation of weather due to this depresson is described.

[学科分类] 大气科学