Also found in: Dictionary, Thesaurus, Legal, Financial, Wikipedia.


production of rainrain,
precipitation in liquid form. It consists of drops of water falling from clouds; if the drops are very small, they are collectively termed drizzle. Rain plays a key role in the hydrologic, or water, cycle in which moisture from the oceans evaporates, condenses into clouds,
..... Click the link for more information.
 by artificial means now generally disregarded, though it is probable that rainmaking hastens or increases rainfall from clouds suitable for natural rainfall. Interest in rainmaking has been spurred by factors including drought and the need for irrigation water. Until recent times it was thought that rain might be induced by explosions, updrafts from fires, or by giving the atmosphere a negative charge. Research during the 1930s showed that rain forms in warm clouds when larger drops of condensed water grow at the expense of smaller ones until they are big enough to fall; also that in cold clouds supercooled water below 5°F; (−15°C;) freezes into ice crystals that act as nuclei for snow. On this basis the American physical chemist Irving Langmuir and his associates carried on Project Cirrus from 1940 to 1952 to find ways to produce rain. Three methods resulted, including spraying water into warm clouds; dropping dry ice into cold clouds, where the dry ice freezes some water into ice crystals that act as natural nuclei for snow; and wafting silver iodide crystals or other similar crystals into a cold cloud from the ground or from an airplane over the cloud, with the crystals hastening the freezing of supercooled water between 27°F; (−2.8°C;) and 5°F;. Overseeding can dissipate a cloud. These techniques are only moderately successful; they cannot be relied upon in case of drought.


See Utah Water Research Laboratory, Development of Cold Cloud Seeding Technology for Use in Precipitation Management (1971); L. J. Battan, Cloud Physics and Cloud Seeding (1979).


Popular term applied to all activities designed to increase, through any artificial means, the amount of precipitation released from a cloud.
References in periodicals archive ?
Naturally, their growth largely depended on rainmaking by their owner-advisors.
this snake played a very important part of rainmaking and other ritual.
62) Moreover, Pikirayi and Chirikure add that it would have been suicidal for a chief or leader to entrust rainmaking functions to himself as it would have invited political instability or anarchy.
The substances augment the clouds' natural rainmaking processes.
It expresses the general values relating to rainmaking rather than an immediate part of an actual rainmaking process.
Minister Safar affirmed the need to benefit from cloud seeding and rainmaking in the field of agriculture and irrigation, particularly in light of the drought and climate changes affecting the region.
NEW YORK Daniel Craig and Hugh Jackman starrer "A Steady Rain" officially kicked off its rainmaking in Week 16--an early indicator of how high demand and premium ticket sales will drive up revenue, just as they did for Julia Roberts starrer "Three Days of Rain" in 2006.
The Rainmaking Presentations System was developed from the analysis of over 8,000 presentations," he explains.
London, Jan 21 (ANI): Scientists have uncovered ashes within archaeological remains in Zimbabwe, which are indicative of ancient rainmaking fires, and can help date droughts in Iron Age Africa.
Live events in the fourth quarter of 2008 included conferences on: rainmaking, negotiating and collaborative development; asbestos litigation; litigation and trial strategies; reinsurance; derivatives litigation; construction defect claims; and, bad faith litigation.
Originally introduced to fight droughts, rainmaking flights are now aimed at tackling pollution
More than a century ago, a meteorologist named Clement Wragg persuaded his local government in the state of Queensland to build rainmaking guns and fire them at passing clouds.