STRUCTURE OF SNOWFALL AND SNOW CRYSTAL DISTRIBUTION 
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TEMPERATURE 
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REL.HUM. CICE SAT.) 
Fic. 10—Growth of snow crystals of thin hollow column type, 11h 20m— 
11h 30m, Jan. 30, 1959; shading in column shows the temperature region of 
snow crystal growth for the crystal type indicated 
hollow column and needle type crystals. As as- 
sumed, it was observed as shown in Figure 10 
that the snow crystals of hollow column grew 
moderately between Point 1000 and Point 500, 
but below Point 500 the erystal type changed 
to needle. The layer between the lower two 
points also was dry, as seen in Figure 10. Dur- 
ing daytime on the 30th, snow crystals of thin 
column or needle type were observed predomi- 
nantly; also various stellar forms occurred. This 
fact means that at a level colder than —S°C 
no snow crystals formed. This may be caused 
by the relatively dry region above the mountain 
seen in Figure 6. 
Time Section D: From about 15h00m on the 
30th, the temperature of the whole atmosphere 
fell, and rimed dendritic snow crystals were ob- 
served simultaneously with those of needle type 
(Fig. 11). Snow erystals of needle type grew to 
some extent and the dendrites began to form 
snowflakes near the level of Point 1000 where 
air temperature was about —8°C. 
Time Section E: Near the end of the observa- 
tion period, the process of the formation of 
graupel of cone-type was observed in detail as 
seen in Figure 12. It seems that the graupel of 
cone-type originates from a rimed branch sepa- 
rated from a rimed snow crystal as pointed out 
by Barkow [1908]. 
Acknowledgments—The writer wishes to thank 
sincerely the Cloud Physics Group and express 
his best thanks to the Hokkaido Broadcasting 
