Cloud Particle Replication in Stormfury Tropical Cumulus

Abstract

An aircraft instrument which provides continuous replication of water droplets and ice particles as an aircraft traverses a cloud is described. The instrument makes use of a continuously moving 16-mm film on which a Formvar varnish is applied just before exposure to the cloud particles at a sampling port. The film then passes through an appropriate drying process, thus producing replicas of the cloud particles in the hardened Formvar coating. The considerations which enter into the interpretation of the replicas are discussed. Two of the problems which greatly limit the amount of quantitative data which can be obtained are 1) shattering of cloud particles (ice or water) either at the film or at the edges of the entry port, and 2) coalescence of water droplets after impaction of the film. Examples are shown of the kind of replicas which were obtained in field use of the instrument.