motion over this continent and the resulting fair weather. Further 

 assuming that the absolute humidity of the air flowing into the continent 

 is about lOg./m.^, the total amounts of water vapour flowing into this 

 continent are — 



For January . . . . 16 x 10^ ° g-/sec. 



For April .. .. 0-86 xlO^o g. /sec. 



For July . . . . 



For October . . . . 0-64 x 10^ ° g./'sec. 



respective^. If these amounts of water vapour are wholly condensed 

 by the converging-ascending motion, the resulting average precipitations 

 over the Continent of Australia are estimated as — 



For January . . . . . . 56 mm. 



For March . . . . . . 3 mm. 



For July 



For October . . . . . , 2 mm. 



Naturally, the air-transport flowing into the continent must be compen- 

 sated by the diverging air in the upper layer over the continent. 



CLIMATIC CHANGE OBSERVED IN JAPAN 



By Takeo Yamamoto, Ube Technical College, Japan 



1. Introduction 



A. Wagner(^) showed the fact that the climate has changed with a 

 tendency for the annual variations of air temperatures to decrease in 

 Europe in the past ever since instrumental observations were established. 

 As for Japan, H. Arakawa(^, ^) pointed out that, barring seeming 

 changes due to the expansion of cities like Tokyo, Osaka, and Kyoto, 

 the mean annual temperature of any place has been practically constant 

 during the past fifty years, thereby concluding that the secular change 

 of the Japanese climate is too imperceptible to be affirmed. This is one 

 fact to be noted, but as climatic change ought to be defined in due 

 consideration of variation in the character of all factors bearing on the 

 annual weather conditions, the annual ranges of air temperatures observed 

 in Japan, for example, also requests careful study in this connection, 

 and the problems concerning the climate change in Japan are to be 

 reinvestigated. 



2. Secular Change of Annual Ranges of Air Temperature 

 Observed in Japan 



With ten-year means of the data I found that the air temperatures 

 in winter season (December, January, and February) are lowering and 

 in summer (June, July, and August) are rising up to the present indicating 

 extreme parts around 1900 a.d. in almost all the regions in Japan as 

 shown in "Fig. 1, in which the curves of secular change of winter and 

 summer temperatures are made by smoothing ten-year means by the 



formula " ^^ — -' 

 4 



I have calculated the annual range of air temperature in each year 

 taking first term of sine series expanded from yearly change of air 

 temperature by the method of harmonic analysis. As will be seen in 



109 



