The Effect of Silver Iodide Seeding on Hailstone Size Distributions


  • Jean Dessens Laboratoire d’Aérologie Université de Toulous Campistrous, France
  • Roberto Fraile Laboratorio de Física de la Atmósfera Universidad de León León, Spain


The hailpad data collected in the ANELFA operational area of southwestern France where hailstorms are extensively seeded from silver iodide ground generators show that hailstone size distributions are modified by the seeding. In the more heavily seeded hailfalls, the number of hailstones with diameters larger than 0.7 cm is decreased, while the number of small precipitation elements (melted or not) is increased; this result agrees with the physical hypothesis of the seeding process. As a consequence, the mean kinetic energy of the more seeded hailfalls is reduced by about 40%, which confirms a previous physical evaluation of the ANELFA project made with a lower number of hail seasons.




Scientific Papers