By Xinhua
Hohhot (China) : China held a rain reduction drill here Wednesday to ensure that the opening and closing ceremonies of the Beijing Olympic Games next year may not be interrupted by possible rain.
Three planes carrying 30 technicians flew for about three hours within a 80 km radius about 8,000 metres above Hohhot, capital of north China’s Inner Mongolia Autonomous Region, spreading silver iodide and 2,800 kg of diatomite into the clouds.
Although the clouds were not as thick as expected and other weather conditions were unfavourable, the drill still collected sufficient data, said Liu Xiaolin, official with the Inner Mongolia weather control office.
The two types of catalyser help to absorb vapour in the cloud and prevent it from forming precipitation.
Apart from the commonly used silver iodide, the environment-friendly diatomite, a kind of white or grey mineral, was for the first time used in rain reduction in China, and its effect is yet to be further studied, said Liu.
Rain reduction only works in a small area, and it would fail in thick or large-scale clouds containing large amounts of water, according to Liu.
The drill, overseen by weather authorities of Beijing and Inner Mongolia, was just part of the rain reduction programme to be launched if needed next August, a month when Beijing is prone to rain.
In addition to rain blocking above the venue area, cloud seeding will be made between 15 km to 120 km away to induce rainfall before it moves to the site of the event.
Rockets would be fired to disperse clouds in case of thunderstorms and other weather conditions too risky for piloted flights.
“We have done a good job in rainmaking, while more research and practices are needed in rain reduction,” said Liu.
Beijing has set up 26 bases around the city to carry out rain reduction projects for the Summer Olympics next year.
The city has been trying to improve meteorological services to serve the event, including accurate weather forecast and air quality reports.
Liu denied suspicions that the drill would worsen the drought plaguing western and middle Inner Mongolia, saying the practice just temporarily suspends precipitation.