Yield Questionable Results : Attempts at Changing Weather Get Cloudy
There are those who talk about the weather and there are those who do something about it.
Vincent Schaffer did something about it. The General Electric scientist dropped dry ice from a plane over the Berkshire mountains on a cloudy day during World War II and watched as snow formed and fell to the ground below.
Ever since Schaffer’s early experiment with cloud seeding, scientists have been attempting to modify the weather to suit the needs of humans below.
‘Bizarre Plans’
“I’ve heard of some pretty bizarre plans,” said Ronald L. Lavoie, a weather modification researcher at the National Weather Service.
Those plans have included painting the polar ice caps black so they would melt and warm temperatures worldwide, sending a power station in orbit that would collect solar heat and send it to Earth in concentrated beams, and spreading a layer of carbon dust in the atmosphere that would create warmth, clouds and gentle rain.
“The energies expended in weather modification are immense considering the results are usually marginal at best,” Lavoie said, adding that forays into weather-modification programs have brought mixed results.
Cloud seeding, popular in the 1950s, is rarely done anymore in the United States, he said. The process involves dropping ash or dust into an existing cloud that is not yet ready to emit rain. Water molecules in the cloud cling to the dust particles, form into raindrops and fall to Earth.
Legal Questions Raised
“Clouds go through life cycles; they grow and decay,” said Lavoie. “Seeding interrupts that cycle and produces only a small amount of precipitation.”
Seeding also brought up legal questions between states, he said. If you seed a cloud over Oklahoma, are you stealing rain that would have fallen in Texas?
The same questions arose over plans to alter the course of hurricanes, he said. What if the hurricane was successfully deflected from Florida but hit Cuba instead?
Lavoie said the U.S. government tried several experiments to lessen the power of hurricanes in the last decade by cooling clouds with ice near the eye of the storms. The cooled air was supposed to slow the inward pull of wind, but Lavoie said the efforts were minuscule compared to the forces working against them.
Tried Defusing Lightning
In other projects, lightning in Colorado has been defused by buckets of small plastic needles dropped into the atmosphere by airplanes.
“The electrical current would bleed off slowly rather than build up into a lightning bolt,” he said. “It worked in a number of cases, but there’s been a lack of interest in pursuing it.”
In the Soviet Union, hail is defused by seeding rain clouds with fine dust sprayed from rockets, Lavoie said. The numerous dust particles prevent water vapor from forming into dangerous clumps.
“They supposedly do this over a very large area,” he said.
Fog banks over airports in Northern regions are often seeded until they melt away, said Lavoie, and ski operators frequently seed clouds over slopes to enhance the snow cover.
“These are small scale,” he said. “We are turning more to influencing the weather rather than changing it completely.”
