S^ fZ'^^9^0C^. JUNE IS,/ 94- 4- 



SKY' SACU 



-f2oa 



800 



-400 



1 r 



Fig. 6. — Example of sea fog of triple layer and its vertical structure at Nemuro. 



Double and triple layers occur mostly in the case of double inversions, 

 (see Fig. 6). 



(7) The top of the inversion observed at Nemuro generalty lies at a 

 height of from 200 to 500 m., but in a few cases it reaches a height of 

 nearly 1,000 m. 



In the case of double inversions the top of the upper inversion is 

 very high ; therefore it might be considered that a very high single in- 

 version forms through the disappearance of the lower inversion of a 

 double inversion (see Fig. 3, where a trace of the lower inversion will be 

 seen). 



(8) Frequently mist or drizzle accompanies dense fog or stratus, 

 precipitation amounting often to more than 2 mm. per hour, and the 

 average size of drops being over 0-2 mm. in diameter. 



(9) When fog or stratus is accompanied with drizzle, minute rain 

 droplets are produced in the middle portion of the fog or stratus layer 

 by the growth of fog particles, and they begin to fall from there. For the 

 first some distance of falling they grow still larger with falling, but when 

 the layer of unsaturated air is present below, falling drops diminish in 

 size and in number on account of evaporation, and sometimes the}' cannot 

 reach the surface (see Fig. 7). 



(10) Wind direction remains almost constant with height, except in 

 the first 100 metres, where wind is apt to turn westward on account of 

 the frictional efiect of the ground (see Figs. 3-5). But in some cases 

 wind changes rapidl}- westward above the top of fog or stratus la3-er. 



74 



