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Table of Contents

Memories of the Bureau, 1946 to 1962





Chapter 1: The Warren Years, 1946 to 1950

Chapter 2: International Meteorology

Chapter 3: The Timcke Years, 1950 to 1955

Chapter 4: A Year at the Massachusetts Institute of Technology

Chapter 5: The Dwyer Years, 1955 to 1962
Leonard Joseph Dwyer—A Complex Character
Reorganising the Bureau
Public Weather Services
Forecasts for the General Public
Importance of Radio Stations
The Advent of Television
Automatic Telephone Forecast Service
Wording and Verification of Forecasts
Services for Aviation
Atomic Weapons Tests
Atomic Weapons Tests—Mosaic G1 and G2
Atomic Weapons Tests—Buffalo 1, 2, 3 and 4
Atomic Weapons Tests—Operations Antler, 2 and 3
Atomic Weapons Tests—Minor Trials
Instruments and Observations
Radar/Radio Winds and Radar Weather Watch
Automatic Weather Stations
Meteorological Satellites
Tropical Cyclones
Bureau Conference on Tropical Cyclones
International Symposium on Tropical Cyclones, Brisbane
Design of Water Storages, Etc
Flood Forecasting
Cloud Seeding
Reduction of Evaporation
Rain Seminar
Cloud Physics
Fire Weather
Research and Special Investigations
International Activities
The International Geophysical Year
The Antarctic and Southern Ocean
International Symposium on Antarctic Meteorology
International Antarctic Analysis Centre
ADP, EDP and Computers
Management Conference
Services Conference
CSIRO and the Universities
Achievements of the Dwyer Years

Chapter 6: A Springboard for the Future

Appendix 1: References

Appendix 2: Reports, Papers, Manuscripts

Appendix 3: Milestones

Appendix 4: Acknowledgements

Appendix 5: Summary by H. N. Warren of the Operation of the Meteorological Section of Allied Air Headquarters, Brisbane, 1942–45



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Cloud Seeding (continued)

I recall that during a discussion of cloud seeding at a meeting of State and Commonwealth Ministers who were members of the Water Resources Council (which I attended as a member of the Council's Standing Committee), Bill Borthwick, Minister for State Rivers and Water Supply for Victoria said "I know that Bill Gibbs has his doubts about the efficiency of cloud seeding but we think we will give it a go". Later in discussing the matter privately with me he said "look Bill, if we are having a drought I will back any remote possibility that seeding will increase rainfall as long as I know that seeding will not decrease it". I appreciated his situation as a politician besieged by drought-stricken farmers. I refrained from informing him that the CSIRO had privately declared that their seeding in the New England region may have decreased rainfall.

The essence of this whole debate has been pointed out by Gerry O'Mahony with reference to a CSIRO cloud seeding exercise in western Victoria. To obtain a reliable assessment of the effect of cloud seeding it is necessary to have a well-designed and well-instrumented experiment with a sufficient number of randomised 'seeding' and 'no seeding' occasions. Gerry believes that for such an experiment in the Western District to be meaningful, it would need to run for many years.

My judgement is that to obtain significant increases in rainfall by artificial means it is necessary to modify cloud dynamics to the extent that condensation rates are significantly increased. Although cloud seeding will modify condensation processes under certain conditions any increase in the amount of precipitation is likely to be very small.

Cloud seeding may cause small increases in precipitation in certain areas under certain conditions but the amount of increase is unlikely to be worth the expenditure necessary to finance the operation. As Gerry O'Mahony has demonstrated, and as the WMO Panel of Experts on which Jack Warner served in the early 1980s concluded, the complexity of the rain process is such that the prospect of obtaining a conclusive answer on the question of the effectiveness of cloud seeding is quite remote.

People in Bright Sparcs - Dwyer, Leonard Joseph; O'Mahony, Gerard (Gerry)

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Gibbs, W. J. 1999 'A Very Special Family: Memories of the Bureau of Meteorology 1946 to 1962', Metarch Papers, No. 13 May 1999, Bureau of Meteorology

© Online Edition Australian Science and Technology Heritage Centre and Bureau of Meteorology 2001
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