With much of the western United States burning throughout the summer, and drought conditions threatening several resort snowmaking operations, many skiers are struggling to put on a happy autumn face. However, help might come from an unlikely source: the fires themselves. While nobody is hoping for more blazes, there may be an upside to all the smoke they produce. Those millions of particles being sent skyward work as a form of natural cloud seeding-a process used by various ski resorts since the 1960s to augment natural snowfall. (Utah alone spent nearly $290,000 on cloud-seeding programs last year.)
The concept gained credibility in 1991, when Mount Pinatubo erupted in the Philippines, sending 15 million tons of ash and gas into the stratosphere and producing the largest cloud of particulate matter since Krakatoa blew in 1883. The cloud spread around the globe in less than three weeks, cooling surface temperatures in some parts of the Northern Hemisphere by as much as 30 degrees Fahrenheit and altering weather patterns worldwide.
Cloud seeding, sometimes called weather modification, involves using planes or ground-based generators to deliver particulates into clouds, usually various amounts of silver iodide. (Clouds are actually highly inefficient precipitators, often retaining more than 90 percent of their moisture.) When organic or inorganic materials are added, they attract water droplets, thus aiding in the formation of ice crystals, which then fall from the sky so we can go skiing.
"It's an interesting question, sort of like the nuclear-winter theory," says Klaus Wolter, a meteorologist and research scientist at the Climate Diagnostics Center in Boulder, Colorado. "Problem is, the first real snowfall is what generally ends the fire season. If large fires are still burning in California or Oregon in late September, then it might have an effect to the east. How big the fire would have to be, I don't know, but it would be an interesting piece of anecdotal evidence."
By early August, wildfires in the U.S. had already burned more than four million acres (over twice the average), including over 300,000 in Oregon alone. Combined with all that smoke, there is another, much bigger weather factor that should bring smiles to skiers' faces: El Niño is back. In July, the National Weather Service announced that a new El Niño is definitely forming. Though it won't be as strong as the one in 1997-98 that made for huge winters across the West, it will mean an increase in wet weather this fall, particularly in the southern half of the country.
While admitting that the effect of smoke on snowfall is negligible, and would never have the punch of an El Niño, Jackson Hole, Wyoming, meteorologist Jim Woodmancy didn't say it was impossible. "If you could just get all of those particles to hover together in one place for a while," Woodmancy said, "then Colorado might be able to charge some of the Eastern resorts for snowmaking."