Theoretical and Applied Climatology

, Volume 46, Issue 2–3, pp 123–133 | Cite as

The use of single seeding events to evaluate the effect of hail suppression

  • H. H. Schiesser
  • J. Bader
  • A. Waldvogel
Article
  • 30 Downloads

Summary

During the years 1977–82 a randomized hail suppression experiment, Grossversuch IV, was conducted in Central Switzerland, testing a Soviet seeding method, which was called the “competing embryo concept”. Due to logistical and technical difficulties there were several seeded hail cells with insufficient seeding coverage. This fact complicates a statistically proper evaluation of the experiment.

To overcome the problem of insufficient seeding, a method is demonstrated, which takes a single seeding event (in our case one rocket) as the statistical unit instead of the seeded cell. The assumption is made that each rocket, which hit the zone of hail formation, reduces the hail production and can be investigated independently from the others. 19 seed cells with 226 truly fired rockets and 18 control cells with 170 simulated rockets, representing over 90% of the total global kinetic energy of all Grossversuch IV cells, were selected. A randomization test is introduced to test the average differences of the true and simulated seeding events. A highly significant increase of kinetic energy after seeding (p-value around 1%) is observed. This result supports the statistically non-significant trend obtained in the confirmatory analysis.

Keywords

Kinetic Energy Randomization Test Seed Cell Statistical Unit Single Seeding 

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References

  1. Chalon, J. P., Fankhauser, J. C., Eccles, P. J., 1976: Structures of an evolving hailstorm, Part I: General characteristics and cellular structure.Mon. Wea. Rev. 104, 564–575.Google Scholar
  2. Federer, B., Waldvogel, A., 1978: Time-resolved hailstone analyses and radar structure of Swiss storms.Quart. J. Roy. Meteor. Soc. 104, 69–90.Google Scholar
  3. Federer, B., Waldvogel, A., Schmid, W., Hampel, F., Rosini, E., Vento, D., Admirat, P., Mezeix, J. F., 1978/79: Plan for the Swiss randomized hail suppression experiment. Design of Grossversuch IV.Pure Appl. Geophys. 117, 548–571.Google Scholar
  4. Federer, B., Waldvogel, A., Schmid, W., Schiesser, H. H., Hampel, F., Schweingruber, M., Stahel, W., Bader, J., Mezeix, J. F., Doras, N., d'Aubigny, G., DerMegreditchian, G., Vento, D., 1986: Main results of Grossversuch IV.J. Climate Appl. Meteor. 25, 917–957.Google Scholar
  5. Heymsfield, A. J., Musil, D. J., 1982: Case study of a hailstorm in Colorado. Part II: Particle growth processes at mid-levels deduced from in-situ measurements.J. Atmos. Sci. 39, 2847–2866.Google Scholar
  6. Mezeix, J. F., 1990: Further exploratory evaluations of Grossversuch IV using hailpad data: Analysis of hail pattern and stratification by storm type for seeding effect.J. Appl. Meteor. 29, 401–417.Google Scholar
  7. Schiesser, H. H., Waldvogel, A., 1985: The seeding coverage of hail cells in Grossversuch IV. 4th WMO Sci. Conf. on Weather Modification, Honolulu, 547-552.Google Scholar
  8. Schiesser, H. H., 1990: Hailfall: the relationship between radar measurements and crop damage.Atmos. Res. 25, 559–582.Google Scholar
  9. Sulakvelidze, G. K., Kiziriya, B. I., Tsykunov, V. V., 1974: Progress of hail suppression work in the USSR, Weather and Climate Modification. New York: Wiley, 410–431.Google Scholar
  10. Waldvogel, A., Schmid, W., Federer, B., 1978a: The kinetic energy of hailfalls. Part I: Hailstone spectra.J. Appl. Meteor. 17, 515–520.Google Scholar
  11. Waldvogel, A., Federer, B., Schmid, W., Mezeix, J. F., 1978b: The kinetic energy of hailfalls. Part II: Radar and hailpads.J. Appl. Meteor. 17, 1680–1693.Google Scholar
  12. Waldvogel, A., Schmid, W., 1982: The kinetic energy of hailfalls. Part III: Sampling errors inferred from radar data.J. Appl. Meteor. 21, 1228–1238.Google Scholar
  13. Waldvogel, A., Klein, L., Musil, D. J., Smith, P. L., 1987: Characteristics of radar-identified big drop zones in Swiss hailstorms.J. Climate Appl. Meteor. 26, 861–877.Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • H. H. Schiesser
    • 1
  • J. Bader
    • 1
  • A. Waldvogel
    • 1
  1. 1.Atmospheric Physics ETHZürichSwitzerland

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