1925 Volume 3 Issue 9 Pages 233-241
There was erected a new mountain observatory on the secondary peak (880m above sea level) of Mt. Unzen Nagasaki. The author has noticed that during three seasons, excepting summer, occasional temperature and humidity anomaly took place in night hours. On these occasions temperature began to rise gradually instead to fall in the evening, average hour being 21h and attained maximum during morning hours average being 1h. At the same time humidity fell instead of rising. Such anomalies appeared generally in the early epock of shifting of the continental high pressure towards east. When it shifted too far east in the Pacific, then the phenomenon was closed. The reason lis not yet clear but the authors view is that it may be due to the descending current from dry continental air, overlying the mountain and surrounding air which forms the forerunner of the travelling high pressure. By the nocturual cooling of lower air, fall wind along the slope must occur, which may pull down the upper continental air. The author examined three other hypotheses, i. e. inversion hypothesis. föhn hypothesis and land breeze hypothesis, and proved all not to be applicable.