The red dust blowing to the original White Mountain snow seems to be nothing more than a curiosity, but this phenomenon is reshaping the water supply throughout the southwest. New research reveals how this dusty snowfall in the Colorado River Basin accelerates snow melting, which could worsen the region’s ongoing water crisis.
In the first comprehensive study of similar studies, Utah researchers analyzed 23 years of satellite data to track how dust affects snow melting across the source of the Colorado River. Their findings, published in a geophysical research letter, show that dust in spring significantly accelerates the snow melting rate, even in years when dust deposits are relatively low.
“It’s not just how much dust is stored in a season, it’s also how long dust is deposited,” said Patrick Naple, a PhD candidate at the University of Utah. “Dust is very effective in accelerating melting because it deposits most frequently in spring, when the day gets longer and the sun is stronger. Even an extra millimeter per hour can make the snow pile disappear for weeks without dust depositing.”
The team found that in high dust years, the dark effect can add 10 mm of extra snow melt per day, which is actually a turbocharged process. This acceleration is most intense in the alpine elevations of the central and southern Rocky Mountains, where most of the water in the Colorado River originates.
Making this finding particularly important is that current water management models cannot explain the effect of dust on melt rate. This supervision leads to the prediction that it has consistently underestimated the rate of snow melt and reaches downstream reservoirs.
“The level of darkness caused by dust is related to the error in predicting water. The water is earlier than expected, which can have real-world effects, for example, if the ground is still frozen, it’s too early for farmers,” explained McKenzie Skiles, associate professor at the university’s School of Environment. “If we can start building dust in predictive models of snow melt, that would make water management decisions more well-known.”
This study found an unexpected pattern—the pollution effect in the second half of the study period (2014-2023) was slightly lower than in the early (2001-2013). The finding surprised the researchers, who expected ongoing drought conditions to increase dust emissions.
Human activity seems to be an important factor in dust levels. “From the Sediment Core record, we know that dust deposits in the region soared after modern settlement in the West. This tells us that the levels of dust we are seeing today are directly related to human activity,” Skiles said.
The study is a critical moment for the Colorado River system, which provides water to 40 million people in seven U.S. states and Mexico. As rivers are already overweight, climate change and growing populations continue to be stressed, it becomes increasingly important to understand the factors that affect the timing of water supply.
For water managers throughout the Southwest, this new dataset provides people with more accurate predictions that can help communities better adapt to the future of every drop of this precious resource.
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