Rapid development of high ice particle concentrations in small polar maritime cumuliform clouds

Abstract

Extremely high ice particle concentrations developed rapidly in the ascending tops of maritime cumulus congestus clouds after drizzle drops had already formed below this level by the collision-coalescence mechanism. In one building cloud with a top temperature no colder than -8°C, the ice particle concentrations increased from 0 to >350 L-1 within 9 min. In another cloud with a top temperature no colder than -13°C, the ice particle concentrations increased from ≤1 to ~1100 L-1 within 12 min. Subsequently, the ice particle concentrations in these clouds decreased, even though the cloud top temperature of one of the clouds continued to decrease to -23.5°C. -from Authors