Chemists and officials worked for weeks on the country's most ambitious ever attempt at weather modification, with air force technicians fanning out across the region to help teams operate complex equipment, the official Xinhua agency said.

 

The evening before the parade chemicals were fired into the hazy skies, and a light rain washed the city clean. Surrounding provinces had already been loading clouds with silver iodide and dry ice, to try and force rain to fall before it reached Beijing, the report added. "Only a handful of countries in the world could organise such large-scale, magic-like weather modification," said Cui Lianqing, a senior air force meteorologist who said the parade operation was the largest in China's history.

 

Contingency plans allowed for the teams to use one kind of chemicals to bring down rain in the parade area, and another to hold it off, he told Xinhua. China has been researching cloud seeding and other weather manipulation techniques since the 1950s