Project ‘climatite’

Summary

Description is made of a non-randomized experiment carried out with the aim of assessing the hail-suppressing effects of some newly-developed, giant condensation and ice-forming nuclei. A further aim consisted in testing, by those means, the practical feasibility of performing a hail-suppression operation by the use of ground-based generators alone. The operational area chosen was the Italian Province of Asti whose extensive vineyards, and regularly-recurring hailstorms, were found to meet the prerequisites of an excellent hailgauge, situated under a reliable hail generator. The project lasted for three consecutive summer periods covering the 153-day intervals between May and September 1969–1971 incl., during which 43.7 tons of nucleator material were dispersed into advancing convective cells.Continuous-historical computations indicated significant reductions of losses to the vineyards of Asti, whilemulti-control-target computations yielded a 99.9% probability of success with 99% confidence limits situated between 51% and 85% of the prospected losses. The average savings were of about 76% of vineyard values, with a corresponding benefit-to-cost ratio of 62, covering manpower, material and communications usedduring those fifteen months.