[quote]China seeders train sights on soggy skies

China seeders train sights on soggy skies
From:Reuters
Thursday, 22 July, 2004
By John Ruwitch

BEIJING (Reuters) - The anti-aircraft battery and rocket launcher at Xiangshan aim straight into a flight path that cuts over the northwestern corner of the Chinese capital.

As Li Ruqing proudly shows off the weaponry, he casts an eye across the courtyard guarded by dogs at a padlocked shed where chemical-tipped shells and missiles are stacked at the ready.

"There is a 30 percent chance we use them tonight," he says.

Li, finger on the trigger, is no madman. Nor does he run some suburban gunnery range for China's air defences. He's a "weather modifier", his weapons disperse chemicals into the sky and his targets are waterlogged clouds.

Cloud seeding, as Li's work is termed, is increasingly common in China, where a chronic drought grips the north and hailstones ruin countless hectares (acres) of crops nationwide every year.

"Our main job," he says with the focus of a seasoned field commander, "is the prevention of hail ... If there is hail heading for Beijing, this is the last line of defence."

Li commands three installations like Xiangshan, or Fragant Hills, in northwestern Beijing where, when the clouds are thick and when he's sure there are no planes overhead, he opens fire on the sky with special rockets and 37-mm Triple-A to make it rain.

In the past, Chinese emperors sacrificed oxen and sheep to draw rains from the heavens. Today, Chinese statistics show that cloud seeding, which can also be done by aircraft, may be somewhat more effective.

This year, some city planners are talking about training their rain guns on another enemy -- the energy shortage that is hobbling China as its electricity-producing capacity struggles to keep up with the booming economy.

The idea: make it rain during the dog days of summer to bring down the temperature and hopefully lower electricity consumption. Shanghai plans to give it a try, and the idea has been broached in Beijing but not yet pursued.

The technique was tried last year in the southern province of Jiangxi, but the results were not publicised, said Chen Zhiyu, head of the national weather modification office.

"They say rainfall was really increased and the results were not bad," Chen said.

CLEAR BENEFITS

Even without precise statistics, the fact that cloud seeding is being talked about as a way to ease the electricity shortage is a testament to the high appraisal of the technique in China.

Seeding has been used for decades, but it has grown quickly since the 1990s. China suffered its worst drought in more than a decade in 2001.

From 1995 to 2003, China spent 2.2 billion yuan on cloud seeding nationwide and now there are 35,275 people in the business of making it rain, China Meteorological Administration statistics show.

Years of drought in northern China have even sparked reports that some towns were complaining of others stealing their rain by seeding clouds as they passed. Li laughed off the idea, saying clouds held more than enough rain to go around.

In 2003 alone, the state spent about 413 million yuan to attack clouds, using 30 planes, 3,800 rockets and 6,900 artillery shells, statistics showed.

The administration says cloud seeding added more than 210 billion cu m (7.4 trillion cu ft) of precipitation from 1995 to 2003.

Zhang Qiang, deputy director general of the Beijing Weather Modification Office, said cloud seeding had increased rainfall by about 12.5 percent in China's capital.

In Beijing, in drought for the sixth year running, weather modification officials have started using rain-making techniques to try to fill up dwindling reservoirs.

The new interest in using cloud seeding to help cool cities also illustrates just how bad the energy shortage is. Officials expect a shortfall of 40,000 megawatts this year, enough to power 40 million households.

Officials in power-short Shanghai say the city will start cloud seeding, perhaps as early as next week. Li, who has about 25 years of experience making clouds rain, said it just might work.

"I would think it is useful, but I've never seen anyone directly do the statistics," he said. "For sure, when the amount of rain increases, the temperature on the ground could go down."

But there were some things even a veteran cloud shooter could not control.

"Man-made rain cannot reduce the amount of sunshine," he said. "And sunshine guarantees that the ground temperature goes up."