DISCUSSION 
151 
S 
3 
ra) 
IN-M 
pe) 
ALTITUDE 
500 
CLOUD 
BASE 
2-1, -10 -5 (°C) 
TEMPERATURE | 
80 90 100 (%) 110 
REL.HUM. (ICE SAT.) 
J 
Fre. 12—Formation of graupel, 16h 10m—16h 20m, Jan. 31, 1959 
upper layers is much less than in the lower layers 
where the ambient vapor density is higher. On 
Mt. Hohenpeissenberg we have observed many 
snowfalls where, during a long period, the col- 
umns dominate, falling doubtless from upper 
layers. Observations on Mt. Zugspitze (2962 m) 
prove that snow crystals of each type, from nee- 
dle and scroll to dendrite and column, occur also 
at this height. Instead of a limit of altitude it 
would be better to use a limit of temperature; for 
example, —20°C. I think the maritime climate of 
Hokkaido is decisive for the predominance of den- 
dritic forms there observed. 
Dr. Ch. Magono (communicated)—As for the 
limits in which the snow crystals of various types 
develop the description by temperature is better 
and more general than by the altitude, as you 
mention, but I would like to take —15°C instead 
om 20°C, 
tively warm temperature region. 
The The snow-crystal 
form except capped columns observed at Mt. 
when the cloudiness extends to rela- 
reason is as follows. 
Teine always seems to be affected by the meteor- 
ological conditions of the air layer warmer than 
the —15°C layer which varied from 
1000 m to 3500 m. This phenomenon appears 
elevation 
to be strange, but it will be understandable if the 
following facts are considered. 
(1) The snow-crystal form is classified by the 
shape of its branches, so the shape of the origi- 
nal small portion, in other words, the portion 
formed in upper air layers, is usually neglected 
in the determination of the classification. 
(2) Usually the vapor 
air layers is much greater than that of the higher 
density in the lower 
layers perhaps owing to the maritime climate of 
Hokkaido, as you note. 
(3) Considerable numbers of small snow crys- 
tals are produced in the lower layers (warmer 
air layers) at the orographic precipitation. 
It is true of course that the snow-crystal form 
observed at the high elevation is affected by the 
air of the upper layers. 
