lastlid
18th July 2012, 07:05
"With the British weather threatening to put a dampener on the Olympic games, why doesn't the government just make the sun shine?
At the risk of sounding like a mad scientist unveiling a doomsday device, it can be done. In theory at least.
The Chinese government seeded clouds ahead of the 2008 Olympics opening ceremony to create a downpour elsewhere and keep the stadium dry.
This involved firing rockets packed with silver iodide crystals into rain clouds over the suburbs of Beijing.
The technique is regularly used to boost rainfall in drought-stricken areas of China, although it has proved controversial with allegations of "rain-theft" levelled at provinces which deploy precipitation shock troops too zealously.
It is also possible to "over nucleate" clouds with many particles so that they hold in their moisture until they have passed over the target area, experts say.
Rockets filled with silver iodide crystals or dry ice are fired into rain clouds from light aircraft or the ground
The icy particles freeze water droplets so that they continue growing in size and eventually fall out of the cloud as snow which turns to rain before it reaches the ground
The method only works on small or medium-sized clouds
Cloud-seeding has no impact on large storm systems
it is also expensive - and there are also environmental concerns about using silver iodide
But it can speed up, delay or change the place where rain will fall
Cloud-seeding is used around the world to prevent fog at airports, stop hail damage in cities or to boost snowfall at ski resorts.
The UK has had a chequered history with the technique. Thirty-five deaths in the 1952 Lynmouth flood disaster came days after RAF rain-making experiments over souther
"
http://www.bbc.co.uk/news/uk-politics-18817945
At the risk of sounding like a mad scientist unveiling a doomsday device, it can be done. In theory at least.
The Chinese government seeded clouds ahead of the 2008 Olympics opening ceremony to create a downpour elsewhere and keep the stadium dry.
This involved firing rockets packed with silver iodide crystals into rain clouds over the suburbs of Beijing.
The technique is regularly used to boost rainfall in drought-stricken areas of China, although it has proved controversial with allegations of "rain-theft" levelled at provinces which deploy precipitation shock troops too zealously.
It is also possible to "over nucleate" clouds with many particles so that they hold in their moisture until they have passed over the target area, experts say.
Rockets filled with silver iodide crystals or dry ice are fired into rain clouds from light aircraft or the ground
The icy particles freeze water droplets so that they continue growing in size and eventually fall out of the cloud as snow which turns to rain before it reaches the ground
The method only works on small or medium-sized clouds
Cloud-seeding has no impact on large storm systems
it is also expensive - and there are also environmental concerns about using silver iodide
But it can speed up, delay or change the place where rain will fall
Cloud-seeding is used around the world to prevent fog at airports, stop hail damage in cities or to boost snowfall at ski resorts.
The UK has had a chequered history with the technique. Thirty-five deaths in the 1952 Lynmouth flood disaster came days after RAF rain-making experiments over souther
"
http://www.bbc.co.uk/news/uk-politics-18817945