Artificial Rain-Making No Answer To Water Shortage

Bay of Plenty Beacon, Volume 13, Issue 71, 30 March 1949, Page 5

Artificial RainMaking No Answer To Water Shortage

The suggestion that in order to avoid power shortages during periods of drought in New Zealand an extension should be made of the exeriments in rain-making by spraying dry-ice from aircraft was referred recently to the Department of Scientific and Industrial Research.

A report was published in America at the end of last year of expensive tests made in cloud seeding technique (as this form of rainmaking is termed), and the conclusion is that dry-ice seeding will not Produce enough precipitation to be :ttseful. .American Experiments

To give these experiments a thorough test, the U.S. Weather Bureau and the U.S. Air Force set up a testing ground of 600 square miles near the Clinton Country, Air Force Base, Wilmington, Ohio. In these ■operations five aeroplanes, 55 ground weather stations, and extensive radar equipment were in use. Nearly nine months were spent on the •experiments, and the U.S. Weather Bureau scientists came to the fol.lowing conclusions:—(1) Not enough precipitation is produced to be economically significant. (2) Very little rain was produced unless there are natural rain within 30 miles. (3) No rain was produced except when there was natural rain falling within 40 to 60 miles. Natural Rain Needed The 117 experiments indicated that appreciable amounts of rain are produced only when large masses of moist air are brought into an area by systems of winds that also produce large scale cooling—that is the way nature gives rain. The cloud seeding techniques do not do this, and will provide no useful -short cuts for relieving droughts, or for fighting bush fires or for any •of the other proposals that require rainfall of economic usefulness.