Abstract
Data gathered during consecutive traverses through summer clouds in southern Missouri have been interpreted to indicate that: (1) the glaciating characteristics of commonly occurring small cumulonimbus clouds in this region are dependent upon the size distribution of the liquid phase prior to the inception of glaciation; (2) clouds having large liquid-water drops rapidly form high concentrations of ice particles regardless of the concentrations of foreign ice-forming nuclei; (3) the ice phase within the clouds does not begin anew; it builds upon the size distribution that has been achieved by the liquid phase and consequently a continuous modification of the particle size distribution within the cloud occurs; and (4) coalescence continues to be a dominant growth mechanism and growth by sublimation essentially is by-passed. The data appear to he compatible with a chain reaction process propagated by the formation of satellite ice particles during the solidification of water drops. Abstract Data gathered during consecutive traverses through summer clouds in southern Missouri have been interpreted to indicate that: (1) the glaciating characteristics of commonly occurring small cumulonimbus clouds in this region are dependent upon the size distribution of the liquid phase prior to the inception of glaciation; (2) clouds having large liquid-water drops rapidly form high concentrations of ice particles regardless of the concentrations of foreign ice-forming nuclei; (3) the ice phase within the clouds does not begin anew; it builds upon the size distribution that has been achieved by the liquid phase and consequently a continuous modification of the particle size distribution within the cloud occurs; and (4) coalescence continues to be a dominant growth mechanism and growth by sublimation essentially is by-passed. The data appear to he compatible with a chain reaction process propagated by the formation of satellite ice particles during the solidification of water drops.