東亞温帯低氣壓の構造(I)

Abstract

Analysing the autographic records of the pressure, temperature, humidity, wind-velocity, winddirection and rain-fall, during 5th to 8th, June 1933, at all stations available, frontal and air mass analyses in the horizontal and vertical sections were made. The principal features of the results may be briefly summarized.(A) The Horizontal Structure.(1) The three air masses such as (see Fig. 2 and 3)(i) Tropical Maritime Air Masses. (TM)……moist, warmest, conditionally unstable and convectively unstable(ii) Transitional Sub-tropical Asiatic Continental Air Masses (JTA)……dry, warm, and conditionally unstable(iii) Transitional Sub-tropical Pacific Air Masses (JTP)…………moist, cold, and conditionally unstable in which J means a transitional air mass, blow out from three high pressure sources and encounter at the center of the yellow sea (Scherhag's Dreimasseneck), and the cyclone rapidly regenerate or develop. Chart 2 shows a typical tropical front cyclone, having three marked fronts in which the tropical warm front is most remarkable. The association of the heavy rain with the fronts is very clearly seen (see Chart 2 and Fig. 15).(2) The cold front moving with the cyclonic center forms a wave like shape by the topographic effect. (Fig. 7)(3) The warm sector are secluded by the topographic effect and a new low pressure area with the residual warm sector are regenerated in the sea to south of Japan proper, The new cyclone are gradually strengthened by acquiring a fresh warm sector and vanished in the Bering Sea with the life of about ten days. (Chart 4, 5, 6, 7 and 8)(4) The part of seclusion and back bent occlusion of the main cyclone are entirely occluded and disappeared in the western part of Okhotsk sea. (Chart 6, 7 and 8)(B) The Vertical Structure(1) The slope of the warm front is 1/190 and the slope of the cold front is 1/50. The characteristic properties of the tropical maritime air masses (TM), which in very clearly distinguished from others, is most conservative because the direction of blowing from southwest is almost unchangeable. (see Fig. 8 and 11)(2) The vertical distributions of the air masses are shown in Fig. 10.