Dusty snow is making the western drought worse
LOVELAND PASS, COLORADOHydrologist Jeff Derry thrusts a shovel into one of the seasons last snowfields on the jagged granite flank of the Continental Divide. Hes looking for something specific: dust.
Standing thigh deep in an icy pit at 11,000 feet above sea level, Derry scrapes his square blade across the dirty snow and dumps its contents into a 1.5-gallon plastic jug. Geologists will analyze the dust to determine its mineral content and pinpoint where it came fromin this case Mexicos Chihuahuan Desert, carried by a historic blizzard a few months earlier.
Im the snow guy who finds himself talking about the desert a lot, says Derry, who directs the largest high-elevation network of dust-on-snow monitoring sites in North America, headquartered about 300 miles southwest of where he stands. There arent many things we can do to tweak the supply side of our water, but one of them is mitigating dust to keep snow around on the surface longer.
Worsening drought in the Wests deserts contributed to a heavy dust season on Colorados Loveland Pass this year, and the tea-colored snow shows it. Soil intermingled with ice crystals fell here on four occasions this spring. Subsequent storms buried each layer of dust particles under new snow. As the air warmed and the days grew longer, the snow melted and by June, the layers had combined at the surface.
https://www.nationalgeographic.com/environment/article/dusty-snow-is-making-the-western-drought-worse