China readies artillery to avert rain at Olympics, but some think idea's all wet
Palm Beach Post Staff Writer
Monday, August 04, 2008
As opening day for the 2008 Summer Olympics draws near, thousands of Chinese villagers are in training. Loading up artillery shells and readying rocket launchers, they await a call to arms.
The villagers aren't part of some civilian security corps. They're part of China's weather modification program. Their mission: to shoot dust into threatening clouds in advance of the opening ceremony Friday in Beijing.
Rain will not be allowed to dampen this Olympic flame.
China is home to one of the oldest, largest and most costly weather modification programs in the world.
In a presentation to climate scientists in Japan, Dr. Zhanyu Yao of the Chinese Academy of Meteorological Sciences recently described the scale of his nation's weather-changing effort: China has 37,000 people, 7,000 artillery guns and 4,700 rocket launchers in place, working in tandem with provincial leaders, meteorologists and radar stations throughout the country. It spends about $63 million a year on the program and claims a benefit worth $1.71 billion a year.
The weather modifiers slake thirsty crops, ward off damaging hail and weaken lightning storms through strategic cloud seeding, spraying dry ice, liquid nitrogen or silver iodide depending on the circumstances, he said.
The technology has been studied worldwide since the 1950s, from Russia to Saudi Arabia, and despite the difficulty of proving its effectiveness, it's still employed, with some controversy, in western states such as North Dakota and California. The debate is always whether cloud seeding made the weather, or the whims of Mother Nature did. Daniel Breed, a project scientist with the National Center for Atmospheric Research, believes the technology can work in certain situations, but not with great precision.
"You can increase precipitation from one individual storm by as much as 50 percent," Breed said. It's also possible to affect the size of hailstones and break up fog banks, he said.
So why hasn't Florida used it to fill up parched Lake Okeechobee or put out forest fires?
Local meteorologists say the technology is ill-suited to Florida's warmer clouds. Plus, it's expensive and fraught with liability potential.
It works best in places where the clouds lack a necessary ingredient for rain or snow: tiny particles that water molecules can grab onto.
"You can't just go out and seed clear skies and make it rain. You have to seed specific clouds at a specific time in their life," said Geoff Shaughnessy, a senior meteorologist with the South Florida Water Management District. "Most of the places where this works, there's a lack of condensation nuclei. Here I would think there's no shortage of aerosols, just from the salt spray and dust from Africa and pollution."
For the Beijing Olympics, where villagers with mobile rocket launchers sit ready to shoot shells heavenward at a moment's notice, the goal isn't to increase rain, but to prevent it.
That has meteorologists and weather modifiers in the United States chuckling. The thought of being asked to seed clouds to prevent rain on Super Bowl Sunday, for example, makes them snort.
"Clouds, pesky critters that they are, you just can't steer them where you want," said Hans Ahlness, vice president of operations at Weather Modification Inc.
His Fargo, N.D., company is working on an $8.8 million research effort to increase Wyoming's snow pack. It's an attractive prospect for utility companies that rely on hydroelectric power.
He says his planes can help pull extra rain from a nimbus cloud, on the order of 10 percent more, but they can't make a cloud appear out of thin air, nor can they stop the rain.
Breed, at the National Center for Atmospheric Research, believes the Chinese scientists are in the unfortunate position of trying to placate their politicians.
"They are kind of stuck between a rock and a hard place," Breed said. "Their scientists privately acknowledge that there really isn't any proof that they can do this kind of stuff."
So what are the chances that it will rain in Beijing on Friday?
China's official meteorologists say there's a 50 percent chance of precipitation. The Games begin as the region's rainy season winds down.
Recalling the fate of China's former food and drug administrator, who was executed for corruption amid product safety scandals, Ahlness, at Weather Modification Inc., said his sympathies were with the Chinese scientists charged with holding the umbrella.
"I don't think I'd want to run their weather modification program," Ahlness said. "I hope they have clear weather just so they don't have to try anything."
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