The science of making snow
December 12, 2012
Ski resorts have been making snow since the 1970s and the equipment and technology used has evolved with resorts’ dependence on man-made snow.
Man-made snow allows ski resorts to ensure a consistent base during the season as well as to extend the season.
Snowmaking has become increasingly complex, with new computerized snow guns that are energy efficient and that can create snow as the surrounding environment allows.
Traditionally, snowmaking operations relied on having a skilled snowmaker who possessed the knowledge necessary to operate the equipment and make snow as the weather allowed.
While many of the larger resorts have made the move to the highly sophisticated and computerized equipment that does not necessarily require a seasoned, knowledgeable snowmaker, at least one resort in Colorado still relies upon a crew of experienced snowmakers to ensure that they have the snow for their guests to enjoy during the winter months.
Scott Uren is the director of mountain operations at Ski Granby Ranch and as such oversees snowmaking operations.
You could call Uren the mad scientist of snow-making. While some resorts turn on their snow-making equipment with the flick of a switch, Uren and his team of winter weather creators are much more involved with their procedures for making man-made snow fly.
Making snow, simply put, is the act of transforming water into ice crystals, or snow. However, the science of making snow is complex despite this simple definition.
Snow guns spray a mixture of water, compressed air, and a nucleating agent into the air. A nucleating agent is an organic material, such as silver iodide, that allows the droplets of water to attach to something and create snow.
The nucleating agent also allows snow to be made at higher temperatures and creates a durable snow that is highly groomable and compressible.
The compressed air as well as the spray nozzles on a gun break the water droplets into smaller droplets, allowing them to freeze quickly and at warmer temperatures.
While the equipment and additives can allow snowmakers to create snow at warmer temperatures, the ability to make snow still relies on two things: Temperature and humidity.
The relationship between temperature and humidity is called the wet-bulb temperature.
The wet-bulb temperature is the temperature the air would be if it were cooled to saturation, or 100 percent relative humidity, where rain and snow form.
At Ski Granby Ranch
While the snow making crews at Ski Granby Ranch do not have the resources to purchase the expensive and automated snow-making guns that many of the larger resorts, like Vail, have come to depend on, they do utilize energy efficient snow guns that allow them to make the same amount of snow while using less energy.
“A snowmaker’s bag is like a golf bag, you need different clubs to play the course,” Uren said. “And we have a driver, a wedge, and a putter.”
Uren’s bag of snow making machines consists of five fan guns, 12 air-water guns, and 12 low-energy guns. They also have another seven low energy guns on their way to the resort.
Uren employs these guns to create what he likes to call a “frozen reservoir.”
Uren refers to the snow he makes as a frozen reservoir because about 80 percent of the water used is returned to the watershed.
“We try to be as environmentally friendly as possible,” Uren said.
So when the end of the season rolls around and you are still sliding on snow, thank the mad scientist of snow making for creating the conditions to keep the winter sports season going.