Beijing has revealed how it will control the weather during the 2008 Olympic Games - by blasting clouds out of the sky.
A battery of antiquated ack-ack anti-aircraft guns stationed around the capital will fire shells filled with chemicals to guard against foul weather. 'We are Beijing's first line of defence for the Olympics. In 2008, we'll shoot any bad weather out of the sky to keep the sun shining on the games,' said Nian Donglian, head meteorologist with the Beijing municipal weather bureau.
Up to 20 of the guns will blast shells packed with silver iodide into the sky. 'When they explode, they scatter the crystals into the clouds, where they attract water and become heavy and fall as raindrops,' said Ms Nian.
The process is better known as cloud seeding and has been used by the army in and around the dusty, parched environs of Beijing for around 33 years to produce much-needed rain for farmers and wash the layers of dust away.
But during the Games the method will be used to eliminate any threat from downpours. 'We sometimes turn a cloudy day into a dry and sunny one by shooting the clouds less intensively than when we make rain - this makes them dissolve. We can even make it snow - but that's still undergoing testing,' added Ms Nian, who says the method is 80 per cent accurate.
'It depends on the thickness and the position of the clouds. Before we fire the ack-ack gun we have to call the airport to check there are no planes in that part of the sky - the last thing we want to do is shoot one down.'
The Olympics are being lauded as China's official international unveiling, and the government wants the watching world to see the nation's capital in the best light.
Ms Nian will be co-ordinating the blitz as she pores over satellite images looking for threatening clouds. Each round costs 69 yuan, and 70 shells are needed to make it rain.
'We also use missiles which cost 1,200 yuan each. Last week we shot around 70 missiles and kept it raining from afternoon through to the night,' said Ms Nian, who has been with the bureau for 13 years.
She added: 'Most of my time is spent looking at satellite pictures of cloud patterns and co-ordinating air traffic control. I then give the signal to the municipal weather bureau and the guys who fire the cannon.'
The government has initiated a range of measures to clean up the smog-bound capital for the Games. Coal-burning factories have been moved out of the city limits, and this year 4,000 buses and 30,000 taxis were replaced with cleaner models. All construction will stop before the Games to let the dust settle.
The municipal government has also launched an etiquette drive which includes anti-spitting patrols, crash courses in politeness for hotel staff and an English guidebook for taxi drivers and police.