of comparing method of similar weather charts, while T. Yazawa and 

 others studied long-range forecasting by means of five-day mean weather 

 charts and classification cards. 



With respect to seasonal forecasting, weather stations in the Tohoku 

 district are co-operating under M. Morita, Director of the Sendai District 

 Central Meteorological Observatory since 1941, in relation to the bad 

 harvest in this district. The results obtained are published in the 

 Journal of the Connecting Society in the Tohoku Meteorological Organi- 

 zation. In these investigations, making use of periodic changes of 

 climate and the relation between climate and drift-ice, remarkable 

 progress has been made in the technics of forecasting, but with respect 

 to scientific or phj^sical basis of the method further studies are yet 

 necessary. 



Studies on lows and typhoons were made in relation to the daily 

 weather forecasting by T. Otani, H. Fuchi, S. Ooma, N. Yamada, and 

 K. Takahasi. In 1942 S. Syono treated the lows from the point of view 

 of vortex. H. Arakawa (1941) and Syono (1947) discussed the instability 

 of Siberian anticyclones. 



In connection with aeronautics, a number of investigations on the 

 upper air meteorology were made, of which special stress was laid upon 

 the improvement of observational instruments. Since 1937 researches 

 on radiosonde and radiotracking were made by D. Nukiyama, H. Yuasa, 

 Y. Shirai, and K. Isono. At present the radiosonde of wave-length 

 variation type is being used. This has been compared with the U.S. 

 radiosonde of frequency modulation type, and it was proved that the 

 accuracy is almost the same for both instruments. Radiosonde and 

 radiotracking are being utilized since 1938 and 1943 respectively. More- 

 over, various sonde instruments for cloud observation, icing observa- 

 tion, &c., are constructed experimentally since 1943. In 1944 D. 

 Nukiyama, K. Tsukamoto, and others began to establish the automatic 

 weather station. 



Concerning the aeronautics, in 1938 H. Arakawa studied the winter 

 bad weather of Japan Sea side by radiosonde observations. Later, on 

 the same subject, studies were made by aeroplane observations by the 

 Army Weather Bureau. The heavy snowfall in Japan Sea side is caused 

 by winter monsoon. Studies concerning this problem have been made 

 during the period from 1943 to 1946 by K. Sugiyama, K. Kunii, T. 

 Kawamoto, and others, and the importance of local front has been 

 found as a result. 



During the years from 1939 to 1944 a synthetic study of cumulonimbus 

 was planned by the Ninth Special Committee for the Protection of 

 Thunderbolt Damage, Japan Society for the Promotion of Scientific 

 Researches. In summer of these years S. Fujiwhara, D. Nukiyama, 

 Y. Kodaira, H. Hatakeyama, S. Syono, S. Sakuraba, and others, con- 

 cerning various branches of this study, were despatched to Maebashi 

 and executed this plan. The results obtained were made public by 

 D. Nukiyama, S. Syono, Y. Kodaira, S. Sakuraba, and others. On the 

 other hand, M. Abe studied the development of cumulonimbus by means 

 of moving pictures. At the time the direction-finder for atmospherics 

 constructed by A. Kimpara was also utilized for the study. During the 

 period 1942 through 1943 many studies were made on the weather in 

 tropical latitudes by the forecasters despatched to those districts. The 

 results obtained were reported by H. Fukuda, K. Hirasawa, S. Daidoji, 



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