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Dirty Snow May Bring Green Burst to Mountain Peaks

from Science News

Kicking up more dust in deserts may bring unnaturally synchronized spring greening to mountain peaks.

Livestock grazing, mining and other human activities in dry lands churn up extra dust that winter storms sweep away and dump on distant alpine slopes along with snow, explains Heidi Steltzer of Colorado State University in Fort Collins.

Darkening the snow speeds up the spring melt of the snowpack, but Steltzer and her colleagues now find that it won't speed up the first sprouts of spring. Premature bald spots instead stay wintry until certain signs of spring pass a threshold, the researchers report online June 29 in Proceedings of the National Academy of Sciences.