Here in Southern Oregon, travel delays at our local airport are not uncommon at this time of year. Snow and ice usually aren’t the culprits, though. Instead, cold-weather inversions can clamp a lid on our valley, sealing us under a layer of fog that can last for days. The problem led to the inauguration of cloud seeding here with dry ice pellets ‘way back in the 1950s. Late in 2009, however, that practice was halted due to new FAA regulations which made piloted-plane seeding too risky (I realize that may not make sense, but it’s complicated).

Airport Director Ben Case and his staff got creative in an effort to stave off costly landing and take-off delays and came up with CASPER — Cable Attached System Providing Effective Release. A $7,500, 18-foot helium balloon combined with a 12-volt battery, a remote control device from a local hobby store, a dispersal device based on a lawn-feeder mechanism, 700 feet of one-quarter-inch-thick line and crushed dry ice make up the effective piece of equipment which, on its first day of use, dispersed the fog in only about 20 minutes. The balloon floats above the inversion layer and disperses the ice into the air, where it freezes the water molecules in the fog, making them fall to the ground like snow. Voilà! Visibility improves so that planes may land.

In the past, a single “fog event” might cost $2,000–3,000, but Director Case estimates CASPER costs less than $500 per use now. Additionally, reloading takes only 5 to 10 minutes as opposed to 45 minutes or more for a second run with a plane. There is no need to maintain an on-call contract with a pilot, since the balloon may be launched by airport personnel with the aid of a maintenance truck. The monetary savings and the effectiveness of CASPER have already got other airports which regularly suffer delays due to fog sitting up and taking notice. The Rogue Valley International-Medford Airport staff have been fielding lots of calls and answering questions about how the system works.

I think this is a great story. It’s a perfect example of finding an open window when a door has been shut . . . or, in this case, finding a hole in the cloud cover when the fog rolls in!

— Patty Vanikiotis, associate editor/copy editor