In order to determine the relative frequency of contact and deposition nucleation in AgI seeded supercooled clouds, laboratory experiments were carried out in which the supercooled cloud drops were tagged with insoluble fluorescent particles. Ice crystals resulting from seeding this cloud with AgI were examined microscopically to locate fluorescent particles. Presence of such a particle in the center of an ice crystal was interpreted as evidence that freezing of a drop through contact nucleation initiated crystal formation. Absence of a tracer particle from an ice crystal center was considered to be indicative of crystals formed by the vapor deposition mechanism. (Modified author abstract).

Performing organization : Calspan Corp. ; controlling office : U.S. Army Research Office, Durham N.C. Final report. DTIC identifiers : Cloud physics, ice formation, cloud seeding, silver iodide, nucleation, crystals. Spiral binding. AD 770 450.