Computation of a "Storm Of Seeding Factor" Hail Suppression by Ground Seeding

Abstract

Cloud seeding experiments using ground generators were carried during three years (1977-1979) in the Italian province of Vicenza. These experiments used A~I generator~,which produced a~ exceptionally high output of nuclei active at -lOVC (2.3 x 10^14) nuclei/hour km ). These were mobile and were operated neath storm trajectory for the duration of the storm. Measurementsof ice nuclei concentrations in the updraftsowhich entered the storm base shows that up to 200 nuclei per litre of air at -10 C were present. The proposed Storm Seeding Factor (SSF), the ratio of artificial to natural nuclei at cloud base, is computed 100 to 500, which is the highest potential for giving positive effects for hail modification.