International Symposium of Hail Defense 2012 Fellbach, Germany 3-4 April 2012
The symposium program:
April 3, 2012
- The basic overview of the work to suppress of hail. Johannes Fuchs, Landrat des Rems-Murr-Kreises
- Reports of the organizations carrying out Anti-hail activities, Georg Vogl, Verwaltungsamtsrat, Landratsamt Rosenheim
- Comparison of the efficiency of liquid-based and pyrotechnic systems used for cloud seeding. Shilin Alexey, Budgetary Institution Obninsk, Rußland
- The main results of the suppression of hail in the area of Stuttgart Prof. Dr. KlausDieter Beheng, Karlsruher Institut für Technologie
- The project is to suppress of hail RO-BERTA, Prof. Dr.-Ing. Peter Zentgraf, M. Sc., Hochschule Rosenheim
- The project is to suppress of hail in Steiermark Dr. Domittner, Ehrenamtlicher Konsulent, Steirische Hagelabwehr
- Hail Suppression in Eastern Switzerland, Armin Bollinger, Vize-Präsident, Hagelabwehrverband Ostschweiz
April 4, 2012
- Optimizing of hail defense generators.
- Analysis of the effects of silver iodide on the environment.
- Intellectual models ( Scientific research, MET aus Langenlois und RO-BERTA Projekt aus Rosenheim))
- Effective Public Relations
- Certification of aircraft and smoke generators
Decisions and resolutions of the symposium
- Conduct official meetings at least once a year to exchange experiences and scientific information
- Conduct joint research and exchange of information available to determine the effectiveness of measures to protect against hail
- Creating a unified system of documentation to assess situations and damage from hail.
- Because there is information on the application of different technical systems of generators, perform research the optimization of the applied technology.
- Necessary to analyze the effectiveness of hail-defense measures in order to prevent damage and minimize the situations of catastrophic hail. Identify methods of minimizing of this situations.
- All organizations, participating in the symposium agree to publish results and inform the other parties in order to conduct joint works.
- Organizations, participating in the conference agree as an important task to provide the work information to new participants and regions practicing techniques of hail-defense.
Comparison of the efficiency of liquid-based and pyrotechnic systems used for cloud seeding
Shilin A.G., Drofa A.S., Ivanov V.N., Savchenko A.V., Shilin V.A.
One of the ways to generate ice-forming aerosols in the process of clouds seeding is the use of liquid-generators the operation of which consists in burning silver iodide solutions and the iodides of alkali, alkaline earth metal or ammonium in an organic solvent. Another method of creation ice-forming aerosols is the burning of pyrotechnic compositions containing active ice-forming substances. Generators of this type can be placed on the ground or on board an aircraft. Such generators are used during the cloud seeding programs with the use of various schemes in France, Spain, Croatia, Austria, Sweden, Cuba, Brazil, Argentina, Chile and China. Generators of this type were used in 1970-80 in the efforts to increase precipitation in the territory of the Ukraine (USSR). It is characteristic that in spite of a wide range of liquid generators application the data on their activity are fairly scanty, and the most of the works performed refer to 1970 – 80s. Almost all the efforts were performed at the scientific institutions of the former USSR (Bahanova, 1990 - 1991).
The data available to us on the effectiveness of foreign liquid-generator systems are fragmentary but in a general agreement with the results of Russian researchers. Figure 1 shows the results of measurements of ice-forming particles for the liquid and pyrotechnic generators according to the literature data and results of our tests. As is shown in Figure 1, there are no liquid systems generating an aerosol with a temperature threshold of lower than minus 6оC, with an acceptable performance, this aerosol reveals its somewhat significant properties only at temperatures below minus 15оC, that does not always correspond to the aim of cloud seeding. As can be seen from the data compared in pyrotechnic compositions containing active ice-forming compounds of silver, liquid generators have the worst characteristics in this case, apart from the low activity of the aerosol at comparable costs, the operational excellence of pyrotechnic systems over liquid ones (constant readiness, sustainable results in the work, greater security, long-term storage) should be noted. As a result, liquid generators have not been used now in Russia and the countries of the former Soviet Union (by about 1990s hey were substituted by pyrotechnic systems).
At the RPA "Typhoon", there are test benches for studying ice-forming efficiencies of full-size generators of a liquid and pyrotechnic type. We conduct studies of the characteristics of generators in conditions close to real conditions in the atmosphere. The data presented in the report were inferred from the studies of different types of generators performed on the stands of the company.
Fig. 1 Comparative characteristics of generators:
ground-based pyrotechnic generator,
airborne liquid generator, joint tests of the Ukraine and RPA "Typhoon",
the model of GIP 2000 (Swedish),
the model of the Chilean generator, GIP 2000 www.smmiab.se,
generator ANELFA, France www.anelfa.asso.fr
- Bahanova P.A. , Kiselev V.I., Kuku E.I. Characteristics of the ice-forming aerosols generated by an generator in air stream. Proceedings of the Ukrainian Research Institute ,1991, № 242. P. 102-110 (in Russian).
- Bahanova P.A., Voit F.I., Lunin G.N. Experience in using the new aircraft aerosol generator "Aqua" in the works on control precipitation. Active influence on hydro meteorological processes: Proc. Reports. Russian Conf., Nalchik, 1991. P. 79–80 (in Russian).
- Bahanova P.A. , Kiselev V.I., Kuku E.I. About increasing the effectiveness of ice-forming reagents in liquid-generators. Active influence on hydrometeorological processes: Kiev, 1987. P. 493-496 (in Russian).