Wed October 8, 2008
Earth Notes - Dust & Snow
Flagstaff, AZ – Earth Notes: Dust and Snow
For those living in the American southwest, dust is as much a part of the environment as dryness and sunshine. Tiny particles seem to get into everything.
While dust can be annoying, scientists believe it plays a vital role in the region's ecology. It appears to provide essential minerals and chemical compounds to high mountain ecosystems, just as sea faring salmon bring ocean nutrients high up into freshwater streams.
But how much dust arrives in the mountains makes a big difference. Ongoing research suggests that increased levels of dust on area snowpacks are dramatically accelerating rates of snowmelt. That's according to Colorado's National Snow and Ice Data Center, and the Center for Snow and Avalanche Studies.
When more dust settles on a snowpack, it becomes darker, absorbs more heat, and melts more quickly. This means moisture runs off faster and less of it is absorbed by underlying soil. The speed-up can play havoc on the storage and release patterns of southwest rivers and reservoirs. Instead of trickling from snowpacks over time, water disappears in a hurry. That results in shortages for plants, animals and people.
Drought is only one source of increased airborne dust. Levels are rising as more land is eroded by off-road vehicles, livestock and housing developments. On desert grasslands that are left alone, winds pick up hardly any dust.
Keeping dust to a manageable level may be essential in assuring that southwestern mountains provide enough water to go around.