GROWTH BY ACCRETION IN THE ICE PHASE 267 
—CU 4gm m-> 
—CU Igm m$ 
--AS 
107 io" 10° 10! 10? 0° 10* 
MASS (x. gm) 
Fic. 3—Effective collection efficiency H’ as a function of particle mass 
for spheres of densities 0.05, 0.2, and 0.9 in Altostratus and in Cumulus of 1 
and 4 gm m“$ 
77) CU 4gm m* 
1o* 
--- 00:05 ra 
02 
09 
to! od Coalescence 
GROWTH RATE (pgm sec!) 
Gl 
10° 
1o* 
MASS (pgm) 
Fic. 4—Growth rate of a spherical ice particle by sublimation and accre- 
tion, as a function of its mass, for various particle densities and in various 
clouds; the coalescence curve shows the growth rate of a liquid droplet in 
4 gm m*Cumulus; particle masses (density 0.9) at which the accretional 
equals the sublimational growth rate in the various clouds are indicated by 
the arrows 
