Snow Science
5:01 am
Mon November 25, 2013

Strange Snow Finding Suggests Fewer Trees Mean More Water

Quick quiz: In springtime, does snow melt faster out in the open or in the shade? 

You might figure it melts faster in the sunshine, and that seems to be the case for cold climates. But in places with temperate winters, like the Pacific Northwest, it might be just the opposite.

Jessica Lundquist, an associate professor of civil and environmental engineering at the University of Washington, has discovered that snow under trees melts faster than snow in clearings. The finding is based largely on research conducted in the Cascade Mountains.

That matters because western states depend on snowpack for their water, especially in early summer. In the long run, snowpack is expected to decrease due to climate change. Lundquist says the new research could help water managers manipulate the mountain forests to maximize the snow.

“They could potentially go and open gaps in the forest, which act like little cold holes or reservoirs for snow. And the snow will melt more slowly. In some ways, it can mitigate the effects of climate change,” Lundquist said.

The warming seems to come from the trees themselves, which absorb and re-emit radiation. It only happens when the climate is right; in colder places, the tree warming isn’t enough to melt the snow faster than the sun does.

Lundquist said she’s working on refining and mapping the information, so water managers could customize their tree-cutting practices to their given climate.