Sierra Nevada snowpacks have been melting faster and faster in recent years, fueled by the effects of climate change. But a new study says that forest fires are also fueling this trend.
At the site of 2015’s Washington Fire, flames charred 18,000 acres of land south of Markleeville, California.
The trees around look like bones. The East Carson River, that flows between them, is swelling with a winter’s worth of snowmelt.
Kelly Gleason studies water management. One day while skiing through a burn area, she spotted something.
“I noticed the snow in that burned area was much darker than the open areas nearby,” Gleason said.
After studying samples and modeling data across the West, Gleason and her team at the Desert Research Institute in Reno found that snow that falls on burn areas tends to melt 5 days faster than unburned land.
“So, after a fire occurs, the canopy burns away, and so more sunlight makes its way through the canopy, which hits the snowpack,” Gleason said.
When the sun shines through these bony trees and hits the darkened snow, it retains more heat, like wearing a black T-shirt directly in sunlight.
That quick melt can have some big effects. Sometimes, for up to 15 years after a fire. Early runoff affects agriculture and wildlife and can extend periods of drought.
“In earlier snowmelt years, that following summer tends to be a really big fire season,” Gleason said.
Gleason’s study shows that 11 percent of all snow zones in the West have been recently burned. The Sierra Nevada takes up a big chunk of that, especially after this past record-breaking fire year.