-

Ice initiation in clouds, a most important field of meteorological
research during the last 50 years, has been of special interest to cloud
modification scientists. However, despite many success in this field there remains numerous ambiguities in the ice nucleation process.
One of the most important source of ice production within clouds is Hallett-Mossop (H-M) ice multiplication process. In this research
work, The H-M process was analyzed at a relatively constant rime surface temperature (Ts =: -5°C) and liquid water content (L we =: 0.93 gm-3) over a high range of updraught velocities than before (from 1.5 to 12 ms-l) with a rotating rod appratus with radii of either
15 or 25 em.
Experiment detected a local maximum of about 35 to 40 splinters per mg of rime close to 3 ms-l. In addition, for the first time it was detected that there is a maximum rate of 60 to 70 splinters per mg of rime at updraught velocity of 6 ms-I, Possibly due to a combination of
rime texture change from feathery to kernel and the ice shell-fracture process. It was found that the radial acceleration at constant updraught velocity did not have significant effects on splinter
production.