Scientists study dust-snowmelt linkage

Boulder, Colo. -- A U.S. National Snow and Ice Data Center-led study indicated that wind-blown dust from drought-stricken deserts can affect snowmelt on distant mountains.

Center researchers at the University of Colorado-Boulder found disturbed lands in the Southwestern United States can shorten the duration of mountain snow cover hundreds of miles away by roughly a month.

Led by Tom Painter, the study found seasonal snow coverage in the sub-alpine and alpine areas of the San Juan Mountains of southwestern Colorado disappeared about 30 days earlier last year because of heavy dust deposition from the Colorado Plateau roughly 200 miles away.

The dust reduced the snow's reflectivity, allowing the sun to warm the snow pack and cause it to melt earlier.

"The connection between dust and lower snow reflectance is already established, but the amount of impact measured and modeled in this system stunned us," said Painter. "The fact that dust can reduce snow cover duration so much -- a month earlier -- transforms our understanding of mountain sensitivity to external forces."

The study that included scientists from the Center for Snow and Avalanche Studies and Northern Arizona University appears online in the journal Geophysical Research Letters.

Copyright 2007 by United Press International.