The amount of precipitation is examined in relation to the upper wind field and temperature field in the pre-summer rainy season in Japan, June and July, for the years 1950 and 1951. It may be well explained as a result of vertical motions of baroclinic unstable waves in the westerlies. In the atmospheric structure during this season, there can be found a similarity to the structure of baroclinic unstable wave. It is found from the data of 1946, 1950 and 1951 that the horizontal distribution of the mean zonal velocity also has some relations with the mechanism of precipitation, which suggests that a more complete, three-dimensional theory of baroclinic instability is needed. Some brief remarkes are given on the relations between the basic flow and the disturbances.
The amount of atmospheric ozone was measured at Tokyo during the period from January 1951 to September 1952, using a chromium photo-electric tube and glass filters (R. Stair's method). According to the results of observation, the amount of atmospheric ozone shows a marked seasonal variation having the maximum value in late spring (about 0.28cm) and the minimum value in fall (about 0.22cm). This agrees fairly well with the results obtained by other observers in similar latitudes. Relations between the deviation of the ozone amount and the surface high and low pressure systems are studied. The positive ozone deviation is found near and in front of a surface migratory anticyclonic center and the negative one is generally found near the center of surface low pressure. An example illustrating the changes of ozone deviation during the passage of a migratory anticyclone (April 24_??_27, 1951) is presented here. By the above observation, the maximum deviation of ozone amount is observed on the day preceding the passage of the anticyclonic center. The large variation in the ozone deviation during the said period can be explained more clearly by considering the change of the air temperature or potential temperature in the lower stratosphere rather than by considering the change of the height of tropopause. A close correlation seems to exist between the wind direction (observed at a single station) in the lower stratosphere and the ozone deviation. In general, as to the vertical motion in the atmosphere, there are upward or downward motions of air in front of or at the rear of a trough at 500 millibar level, and reversed motions are assumed to exist in the lower stratosphere. Using the above mentioned result, the authors studied the relation between the ozone deviation and the vertical motion in the lower stratosphere. According as the observing station is situated in front of or at the rear of a trough on the 500 millibar weather map, the ozone deviation seems to become positive or negative, respectively.
An electrochemical apparatus for the measurement of atmospheric ozone which was originally developed by A. Ehmert was constructed, and practical observation with it were carried out three times a day at the summit of Mt. Fuji from 13th to 18th of August 1953. According to the results of observation, the ozone concentration increases anomalously before the occurrence of St. Elmo's Fire. An notable decrease which is presumably related with the passage of frontal zone was also observed. Ehmert's method of determination of atmospheric ozone is criticized from the viewpoint of meteorological observation.