Utah's Famously White Snow Is Getting Dusty

Dust blowing off the dry areas around the receding Great Salt Lake is coating the famously ski-friendly pure white snow on nearby slopes and causing early melting—a big problem with wide-ranging effects for Utah, reports Smithsonian Magazine. In a study published by Environmental Research Letters, University of Utah hydrologist McKenzie Skiles and her colleagues looked into what was going on with the dirty snow on slopes near the lake. They found that in 2022, snow coating the Wasatch Mountains was the dustiest it had been since researchers began tracking levels 14 years ago. The biggest source of the dust, about 50%, is a desertlike region west of the city, but a quarter of it came from the Great Salt Lake, the researchers found.

The dust makes the snow melt faster, which translates into a shorter ski season at popular resorts—draining away tourist dollars—and added pressure on water systems, reports Science News. The latter are made to handle steadily flowing melt water, not sudden cascades. Additionally, faster snow cover loss leads to a heightened danger of wildfire due to dry forests. Scientists found that the dirtier snow made the regional snowpack melt 17 days faster in 2022, per a release at Phys.org. "You might see 17 days and think it's no big deal, but our current snowmelt models don't account for dust," says Skiles. And the dust situation may only get worse in the years to come.

Smithsonian describes a "vicious cycle" at play: "When the snow melts earlier in the spring, that means the landscape dries out more quickly during the heat of the summer. That drier landscape, in turn, then contributes more dust to the snow, making it melt even faster." The shrinking lake worsens the problem because a smaller lake translates to a smaller snowpack in the mountains. CNN reported earlier this year that some scientists worry the shrinking lake could lead to the more widespread danger of a "toxic dust bowl." Bonnie Baxter of the Great Salt Lake Institute at Salt Lake City's Westminster College calls it "an ecological disaster that will become a human health disaster." (More Great Salt Lake stories.)