Increasing dust speeds melting of mountain snow

Throughout memory the warmth of spring has begun the mountain snowmelt, bringing life-giving water to greening plants so they can blossom and renew their species.

But now, scientists say, the timing is being thrown off by desert dust stirred as global warming dries larger areas and human activity increases in those regions.

This dust darkens the surface of winter snows, which warms it by absorbing sunlight that the white surface would have reflected. That causes the snow to melt earlier than in the past and to run off before the air has warmed enough to spur plant growth, researchers report in Tuesday's edition of Proceedings of the National Academy of Sciences.

“It is striking how different the landscape looks as result of this desert-mountain interaction,” Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, Colorado, and a co-author of the report, said in a statement.

The researchers established test plots in the San Juan Mountains in southern Colorado. Some plots were left alone to collect snow and dust naturally; others had extra dust added and a third group had naturally arriving dust removed.

On average, according to the study, cleaning away the naturally arriving dust delayed snowmelt by 11 days compared to the plots that were left alone. Adding dust sped up the melt by 7 to 13 days.

Subscribe to The China Post and save 25%. Click here

SharePrintEmail

Write a Comment

Terms

Enter your comments - 3000 characters max

Type in image code

Submit

 Receive China Post promos
 Respond to this email