Swiss randomized hail suppression experiment, Grossversuch IV

Grossverusch IV is a collaborative project, coordinating under direction of the Institute for Atmopsheric Physics of ETH in Zurich, participation of universities and government agencies of France, and Switzerland. Each participating group will contribute its expertise to the following defined objective of the project: to test whether a hail suppression method similar to the one proposed by in the USSR, using their high altitude rockets, can successfully be applied in central Europe, taking into account the climatic, and logistic boundary conditions of our regions. The requirements for carrying out such an experiment are (1) a test area with no air-traffic, a high hail frequency, no valuable crops and no people’s problem; (2) a 3 cm radar with PPI and RHI for measuring the parameters needed for the seeding criterion; (3) 6 launchers for Oblako rockets to cover the area of I00’000 ha (+ 1000 km^2) with sufficient overlap; (4) a 10 cm radar with PPI to measure precipitation quantitatively and; (5) a ground network of hailpads with sufficient densityto measure kinetic energy and mass of hail in the test area. The area, which conforms to point 1, lying between Lucerne and Langnau, is reported together with the horizontal range of the Soviet rockets and boundaries of the French and Italian ground networks……