Stormfury Cumulus Experiments: Preliminary Results 1965

Abstract This paper is a preliminary summary of results of a tropical cumulus seeding experiment. Individual supercooled cumuli were seeded by silver iodide pyrotechnics and studied before and after by radar, photography and multi-aircraft penetrations. The choice of “seeded” versus “control” cloud was made from sealed instructions opened on the seeding aircraft. Twenty-two cases were studied on nine days, with fifteen seeded and seven controls, largely in matched pairs. Two-thirds of the properly seeded clouds underwent marked vertical growth while six-sevenths of the controls did not. It is suggested that this and sequel experiments can delineate conditions under which seeding may have different effects upon clouds.