The Mechanism of Precipitation Formation in Northeastern Colorado Cumulus II. Sailplane Measurements

Abstract

Some cloud microphysical measurements made from the sailplane The Explorer are presented. Drop sizes and concentrations and ice particle sizes, concentrations, shapes, and, in some cases, internal structures are determined from in situ photographs taken with a recently developed particle camera. The data from photographs taken in northeastern Colorado during the early stages of the development of spring and summer cumulus clouds and in their precipitation suggest that the first precipitation forms primarily by the ice process rather than by condensation?coalescence. Ice particles were frequently photographed in these clouds, but above the freezing altitude, water drops > 50 ?m radius were very rare.