Is it all too much?

I couldn’t help but notice the recent press reports of how the weather was going to be dealt with for the 2008 Beijing Olympics.1 Having picked the wettest month of the year to hold the Olympic Games, the Chinese have developed one of the world’s largest weather modification strategies. Weather patterns over Beijing in recent decades indicate a 50% chance of rain during the Games. Clearly, this a problem that is in dire need of an Olympic-standard solution.

If a storm approaches the city, the Chinese reportedly said they would seed the clouds with silver iodide to force rainfall at a distance from the venue, thereby ensuring spectators and athletes stay dry. I gather from the reports that this is not an exact science because if too much silver iodide is added to clouds heavy with moisture, it can overwhelm their ability to condense, thereby stopping the rain or, even worse, producing hail. Scientists must make educated guesses about how much silver iodide should be dispersed, the best time for it and the best method of delivery.

Apparently this field is rich in history with devices such as ground generators or cannons that create a mist of silver iodide particles that float upward toward the clouds. Pyrotechnic rockets have also been used for more dramatic effect. More modern methods to disperse the silver iodide use seeding by airplanes. …