The precipitation particles mostly form through the ice phase, although raindrops that form by collison and coalescence are observed in some clouds with warmer bases. The clouds typically contain high concentrations of ice in their later stages. It is likely that the Hallet-Mossop process of splintering during riming operaties in these clouds and is responsible for the high concentrations of ice that are observed. We have developed a model of this process where ice particles grow in a multi-thermal framework. We find that the rate of glaciation has the strongest dependence on the cloud liquid water content.
Rapid glaciation can occur if adiabatic cores are present.
Field Projects Great Dun Fell Cap Clouds Experiment . Meppen Fog Experiment . Socorro Doppler Radar Experiment . Socorro King Air Experiment . Honiara, Solomon Islands.