The universities and government agencies of France, Italy, and Switzerland are participating in Grossversuch IV, a collaborative project designed to test whether a hail suppression method similar to that of the U.S.S.R. and using Soviet high-altitude rockets can successfully be applied in Central Europe (Federer 1975). area between Lucerne and Langnau has an average of 35 thunderstorm days per year with 16 being haildays. This test area was selected because it has no air traffic, no valuable crops, and no residents to be endangered by the use of rockets. Lead iodide is the seeding agent being used in the randomized experiment; radar and a ground network of hailpads are being used to identify hail clouds and to provide measurements of hailfall. Canada's Alberta Hail Project was summarized by Renick (1975). The project was initiated in 1973 to hasten the development of hail suppression technology and test it on a wide scale. The target area covers 18,500 square miles, and cloud seeding is conducted by seven aircraft either from cloud top with dropable pyrotechnic flares, or from cloud base with flares mounted on the wings. Radar data from storms will be combined with hailfall data and crop damage information for seeded and unseeded storms for evaluation of the seeding effectiveness. The primary hypothesis assumed for the experiment is the competing embryo concept. This hypothesis states that the introduction of sufficient artificial ice nuclei into the updraft of hailproducing clouds leads to the formation of more hail embryos. These will then compete for the available liquid water in the storm and form more but smaller and less damaging hailstones. Only a limited number of storm analyses have been completed and not all have shown the same result. References Changnon, S. A., Jr., 1975: The Paradox of Planned Weather Modification, Bull. Amer. Meteor. Soc., 56, 27-37. Changnon, S. A. Jr., and G. M. Morgan, Jr., 1976: Design of an Experiment to Suppress Hail in Illinois, Bulletin 61, Illinois State Water Survey, Urbana, 100-105. Colorado International Corporation, 1975: For Rainfall Augmentation in the Lualaba Watershed, 1974-75, Final Report, Colorado International Corporation, Boulder, Colo., 38 pp. Davis, R. J., 1974: Weather Modification Litigation and Statutes, published in "Weather and Climate Modification", W. N. Hess, editor, John Wiley and Sons, New York, 767-786. Davis, R. J., and P. St. Amand, 1975: Proof of Legal Causation in Weather Modification Litigation: Reinbold v. Sumner Farmers, Inc., and Irving P. Krick, Inc., J. of Weather Modification, Vol. 7, No. 1. 127-143. Dennis, A. S., J. R. Miller, Jr., D. E. Cain, and R. L. Schwaller, 1975: Evaluation by Monte Carlo Tests of Effects of Cloud Seeding on Growing Season Rainfall in North Dakota, J. Appl Meteor. 14, 959-969. Droessler, E. G., 1975: Weather Modification - Some Proposals for Farhar, B. C., 1975: Weather Modification and Public Opinion in South Dakota, Preliminary Findings, J. Weather Modification, Vol. 7, No. 1, 145-153. Federer, B., 1975: Swiss Randomized Hail Suppression Experiment, Grossversuch IV, J. Weather Modification, Vol. 7, No. 2, 177-179. Gatz, D. F., 1975: Background Silver Concentrations in Illinois Precipitation and River Water, J. Appl. Meteor., 14, 217-221. General Accounting Office, 1974: Need For A National Weather Modification Research Program, Report to the Congress B-133202, Comptroller General of the U.S. General Accounting Office, Washington, D. C. Girdzus, J., 1976: The 1975 CRMWD Weather Modification Program and Hacker, D. W., 1975: A Lawsuit Grows From Cloud Seeds, The National References Changnon, S. A., Jr., 1975: The Paradox of Planned Weather Modification, Bull. Amer. Meteor. Soc., 56, 27-37. Changnon, S. A. Jr., and G. M. Morgan, Jr., 1976: Design of an Experiment to Suppress Hail in Illinois, Bulletin 61, Illinois State Water Survey, Urbana, 100-105. Colorado International Corporation, 1975: For Rainfall Augmentation in the Lualaba Watershed, 1974-75, Final Report, Colorado International Corporation, Boulder, Colo., 38 pp. Davis, R. J., 1974: Weather Modification Litigation and Statutes, published in "Weather and Climate Modification", W. N. Hess, editor, John Wiley and Sons, New York, 767–786. Davis, R. J., and P. St. Amand, 1975: Proof of Legal Causation in Weather Modification Litigation: Reinbold v. Sumner Farmers, Inc., and Irving P. Krick, Inc., J. of Weather Modification, Vol. 7, No. 1. 127-143. Dennis, A. S., J. R. Miller, Jr., D. E. Cain, and R. L. Schwaller, 1975: Evaluation by Monte Carlo Tests of Effects of Cloud Seeding on Growing Season Rainfall in North Dakota, J. Appl Meteor. 14, 959-969. Droessler, E. G., 1975: Weather Modification - Some Proposals for Farhar, B. C., 1975: Weather Modification and Public Opinion in South Dakota, Preliminary Findings, J. Weather Modification, Vol. 7, No. 1, 145-153. Federer, B., 1975: Swiss Randomized Hail Suppression Experiment, Grossversuch IV, J. Weather Modification, Vol. 7, No. 2, 177-179. Gatz, D. F., 1975: Background Silver Concentrations in Illinois Precipitation and River Water, J. Appl. Meteor., 14, 217-221. General Accounting Office, 1974: Need For A National Weather Modification Research Program, Report to the Congress B-133202, Comptroller General of the U.S. General Accounting Office, Washington, D. C. Hacker, D. W., 1975: A Lawsuit Grows From Cloud Seeds, The National Henderson, T. J., 1975a: Operations Sites in the A Visit to Various Weather Modification spherics Incorporated, Fresno, California, 56 pp. Henderson, T. J., 1975b: The Kenya Hail Suppression Program, J. Heng, T. H., and H. T. Yuen, 1975: An Experimental Study of Flood Control by Cloud Seeding Technique in Malaysia, Proc. of WMO Technical Conference on Typhoon Modification, October 1974, WMO-408, World Meteorological Organization, Geneva, Switzerland, 101-108. Interdepartmental Committee for Atmospheric Sciences, 1976: National Atmospheric Sciences Program, Fiscal Year 1977, Report 20, National Science Foundation, Washington, D. C. Isaac, G. A., J. I. MacPherson, and L. B. MacHattie, 1975: Forest Jones, E. B., C. F. Leaf, and W. H. Fischer, 1975: Generalized Criteria for Verification of Water Developed Through Weather Modification, M. W. Bittinger and Associates, Inc., Fort Collins, Colo., 154 PP. Journal of Weather Modification, 1975: Vol. 7, No. 2, Weather Modification Association, P.0. Box 8116, Fresno, Calif., 93727, 179 pp. Kellogg, W. W., D. Atlas, D. S. Johnson, R. J. Reed, and K. C. Spengler, 1974: Visit to the People's Republic of China: A Report From the AMS Delegation, Bull. Amer. Meteor. Soc., 55, 1291-1330. McNaughton, D. L., 1975: Seeding Single Clouds Using Pyrotechnic Cartridges, 1973-74, J. of Weather Modification, Vol. 7, No. 1, 4-16. Mordy, W. A., 1975: Weather-Climate Modification, Reviews of Geophysics and Space Physics, Vol. 13, No. 3, American Geophysical Union, Washington, D. C. 746-752, 841-846. Murty, A. S. Ramachandra, A. M. Selvam, and Bh. V. Ramana Murty, 1975: Dynamic Effect of Salt Seeding in Warm Cumulus Clouds, J. of Weather Modification, Vol. 7, No. 1, 31-43. A Report National Advisory Committee for Oceans and Atmosphere, 1975: to the President and Congress, 4th Annual Report, National Advisory Committee on Oceans and Atmosphere, Washington, D.C., 48 pp. National Center for Atmospheric Research, 1975: Symposium and Workshop on Hail and Its Suppression - Working Group Reports, National Hail Research Experiment Technical Report NCAR 7100-75-2, National Center for Atmospheric Research, Boulder, Colo., 130 pp. |