Fig. 2. — Sea-surface temperature in the first decade of August, 1941. This year 

 predominance of the Oya Shio \vas late. (After daily information from ships 

 to the Central JVleteorological Observatory.) 



mist or drizzle whose precipitation amounts to a not negligible quantity, 

 so that there must be upward motion of the air as a whole in order to 

 maintain the upward supply of water vapour and at the same time to 

 suspend growing fog particles in the air. But stich ascending motion 

 •of the air might not be expected by the convection theory. 



The present author has suggested a new theory in 1944, the outline 

 ■of which will be seen in the last part of this paper. This theory has 

 proved the possibility that the warm air moving over the cold water 

 might have ascending component of velocity. 



The Nature of Sea Fog of Ada^ection Type 



On the basis of the observations of the present author and many 

 other persons the nature of sea fog of advection type has been 

 summarized below : — 



(1) In June- July and sometimes in August sea fogs of advection 

 type occur frequently in the regions immediately surrounding the 

 Kuril Islands and along the Pacific coasts of Hokkaido, the densest 



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