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When San Diego Hired a Rainmaker a Century Ago, It Poured | JSTOR Daily
"Critics claimed Hatfield was a huckster who merely benefited from coincidence. As Spence pointed out, many so-called rainmakers “were little more than gamblers, betting their time and what reputation they may have had that rain would fall while or after they commenced their machinations.” By working only in the midst of dry spells, Hatfield could improve his odds of timing an impending rainfall. Indeed, Hatfield likely profited from his keen knowledge of meteorology and close examination of weather records. Knowing when storm fronts were imminent, he could target cities in advance of the rain and claim success when moisture fell from the skies.

Others saw Hatfield as a forerunner of modern-day cloud-seeding, in which chemicals such as dry ice and silver iodide—perhaps among those used by Hatfield—are introduced into cloud banks to foster the formation of ice crystals and raindrops. These chemicals provide particles around which water vapor can condense and eventually fall as rain once the droplets reach a sufficient size. The condensation process generates its own heat, which causes air to rise and fosters the growth of additional rain clouds.

While Hatfield relied on the ascension of chemical vapors into the skies, rainmaking went airborne with the advent of the aircraft. The U.S. Army Air Service began experiments to determine if rain could be produced from electrified sand in 1921; however, the modern science of rainmaking truly began in 1947 with Project Cirrus, a joint venture of General Electric and the U.S. military under the direction of Nobel laureate Irving Langmuir that seeded clouds with dry ice. “The results of Project Cirrus gave scientific credence to the mystic works of such pioneer rainmakers as California’s now famous Charles Hatfield,” wrote Donald D. Stark in the California Law Review.

A century after Hatfield’s exploits, the science of rainmaking and the effectiveness of cloud-seeding remain points of contention, as Virginia Simms wrote in a 2010 article in The International Lawyer. Even so, cloud-seeding is on the rise. A 2014 report from the World Meteorological Organization found that 52 countries had active cloud-seeding programs, up from 47 the previous year, and 39 weather-modification programs were in place west of the Mississippi River.

Even after its experience in 1915, San Diego continued to be seduced by the hope offered by rainmakers. Incredibly, in 1961, the city council considered hiring Edmond Jeffery, who promised he could make it rain 40 inches in 40 days for a fee of $8,000. This time, with memories of “Hatfield’s Flood” still echoing in their minds, San Diego’s councilors refused the offer."
sandiego  california  drought  history  charleshatfield  rain  water  via:vruba  1915  1961  edmondjeffery  cloudseeding 
december 2015 by robertogreco
Planes and snowfall: Planes may increase snowfall at times - latimes.com
Some jets and propeller planes flying through certain kinds of clouds can seed ice crystals and create additional snowfall, scientists find.
Summer  2011  July  snow  jets  CloudSeeding 
july 2011 by ahasteve
Planes and snowfall: Planes may increase snowfall at times - latimes.com
Some jets and propeller planes flying through certain kinds of clouds can seed ice crystals and create additional snowfall, scientists find.
Summer  2011  July  snow  jets  CloudSeeding 
july 2011 by ahasteve

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