Numerical experiments to explore the optimal scheme of hail suppression with seeding

The IAP Three-Dimensional Convective Storm Model is used to simulate the cell hail cloud occurred on 5 June 2016 in Sanmenxia City, Henan province. Seeding method, time, area, and dose are dynamically combined into 81 schemes. We can more efficiently and subtly explore the ranges of seeding operation indicators that produce significant hail suppression effect, and the optimal combination scheme. Results show that:(1) Seeding method, time, area and dose with significant hail suppression effect are neither fixed nor unique. Hail suppression with seeding should be conducted the sooner the better. Significant effect of suppression with seeding depends on appropriate combination schemes of indicators. The scheme of seeding vertically, at the early hailstorm, in center of the hail supercooled water content, and with maximum dose in reasonable range, can produce the most significant effect of hail suppression. (2) The decrease of hail converts to the increase of rainfall, and the total precipitation is increased. (3) The total amount of hail is reduced by the decrease of graupel into frozen drop and the collision of hail and cold cloud water. (4) The maximum of hail water content is decreased by 80% compared to no-seeding scheme.