ISOLATED CUMULUS CLOUD MODIFICATION PROJECT

Abstract

A randomized seeding experiment was conducted in Flagstaff, Airz, in July and Aug of 1967 wherein the heights, rainfall amounts and rainfall durations of isolated cumuli were measured. Twenty-one clouds were studied, 10 seeded and 11 not seeded, on 11 days. On 9 days there were paired seed and no-seed events. The project aims were to show distinct effects of seeding on cloud-top height, rainfall and duration; to verify and/or improve the model; and to use the model to interpret the importance of the seeding effect.