Estimation of the deposited silver-iodide in the Hail Suppression Project in Serbia

Hailstorms are considered to be among the most devastating weather manifestations. The devastation encouraged operational hail suppression activities to be undertaken in many countries (e.g. Ćurić,1990;Dessens,1998).“Hail suppression project” in Serbia uses the anti-hail rockets to inject the silver iodide agent into the hail clouds (one rocket has 400 g of mixture with 10-20% of AgI agent). The target area is between isotherms of 8°C and -12°C and radar echo contours of 25 and 45 dBZ. This project has a very dense network of stations with rocket launchers (the mean distance between sites is 5 km) in operative use continuously over forty years. The total target area is 77.498 km with 51.069 km of agricultural area. The voluntary observers reported days when hail and other precipitation types (classified in nine categories) from Cumulonimbus (Cb) clouds occurred at their stations. All hailstorms moving over target area were monitored by S-band radar detectors located at 13 radar centers presented in Fig. 1. The launching site is shown in Fig. 2. There are minor number of studies dealing with aftereffects of weather modification activities. Most of these studies investigate the persistent