Study shows desert droughts lead to earlier annual mountain snow loss

Jun 25, 2007
Dust on Mount Sopris
A visible layer of dust coats the snow on Mount Sopris in Colorado's San Juan Mountains on May 16, 2007. Credit: Penn Newhard

A new study spearheaded by the University of Colorado at Boulder’s National Snow and Ice Data Center indicates wind-blown dust from drought-stricken and disturbed lands in the Southwest can shorten the duration of mountain snow cover hundreds of miles away in the Colorado mountains 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 by about 30 days earlier in 2006 because of heavy dust deposition from the Colorado Plateau roughly 200 miles away. The dust, which probably came from northeast Arizona and northwest New Mexico deserts, reduced the snow’s reflectivity, allowing more of the sun’s energy 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 forcings.”

While just three or four significant dust deposition events occurred annually in the San Juan Mountains between 2003 and 2005, eight occurred in 2006, according to the authors. In 2006, the sub-alpine regions of the San Juans melted out 24 to 35 days earlier than previous, relatively dust-free years, according to ground measurements and computer simulations.

A paper on the subject was published online June 23 in Geophysical Research Letters. Co-authors on the study included CU-Boulder’s Andrew Barrett, Jason Neff, Maureen Cassidy, Corey Lawrence and Lang Farmer, as well as Christopher Landry from the Center for Snow and Avalanche Studies in Silverton, Colo., and Kathleen McBride of Northern Arizona University.

The Colorado Plateau is centered in the Four Corners region of Colorado, New Mexico, Arizona and Utah and covers an area of roughly 130,000 square miles.

Prior to the widespread ecological disturbance of the Western U.S. in the late 1980s, the high mountain snow would have likely lasted several weeks longer in most regions, according to the researchers.

“Recent studies agree that with global warming, the Southwest will be warmer and drier,” said Painter. “Enhanced dust deposition is likely, further shortening snow cover duration. Ultimately, a warming climate and the dust it generates will affect river run-off and soil moisture in the mountains, not only in the Western United States but across many of the world’s mountains.”

Snowmelt provides drinking water to one-sixth of the world’s population and provides important agricultural and recreational resources for the Western United States, said Painter. The progression of climate change may alter the reliability of spring snowmelt, including its quantity, timing and duration, he said.

Source: University of Colorado at Boulder

Explore further: Synchronization of North Atlantic, North Pacific preceded abrupt warming, end of ice age

add to favorites email to friend print save as pdf

Related Stories

Tornado debris study could lead to better warnings

Mar 18, 2013

Photos and mementoes that were snatched up and blown hundreds of miles during tornados in the south of the United States two years ago are giving researchers new insight on how debris is carried by the storms ...

CSI: Milky Way

Mar 06, 2013

These days the core of the Milky Way galaxy is a pretty tame place... cosmically speaking. The galactic black hole at the center is a sleeping giant. Existing stars are peacefully circling. Although conditions ...

Signs of ancient flowing water on Mars

May 07, 2012

(Phys.org) -- ESA’s Mars Express has returned images of a region on the Red Planet that appears to have been sculpted in part by flowing liquid. This again adds to the growing evidence that Mars had large ...

Recommended for you

Fires in Central Africa During July 2014

5 hours ago

Hundreds of fires covered central Africa in mid-July 2014, as the annual fire season continues across the region. Multiple red hotspots, which indicate areas of increased temperatures, are heavily sprinkled ...

NASA's HS3 mission spotlight: The HIRAD instrument

16 hours ago

The Hurricane Imaging Radiometer, known as HIRAD, will fly aboard one of two unmanned Global Hawk aircraft during NASA's Hurricane Severe Storm Sentinel or HS3 mission from Wallops beginning August 26 through ...

Fires in the Northern Territories July 2014

Jul 23, 2014

Environment Canada has issued a high health risk warning for Yellowknife and surrounding area because of heavy smoke in the region due to forest fires. In the image taken by the Aqua satellite, the smoke ...

User comments : 0