Air Pollution Now Melting Snowpack Quicker, Study Shows

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Written by Timothy B. Hurst
Published on January 28th, 2009

A new study shows that pollution from automobiles and coal-fired power plants is contributing to the melting of mountain snowpacks up to a month early, exacerbating water shortages and polluting streams in the arid West.

We’ve all seen it. That white fluffy blanket of snow that looked so nice after it fell a couple weeks back is no longer white and fluffy. It has been capped with a layer of dark sooty particulate matter, turning it from white to gray to black. Having grown up in the Boston area, this was the reality of virtually every snowstorm I can recall from my youth. But that dark, sooty particulate matter that builds up on the stale snow is not only an aesthetically unpleasing feature of urban landscapes in the winter, it happens in the North American snowscapes of the Rockies, the Sierra Nevadas and the Cascades - with far more serious consequences.

A peer-reviewed study conducted by scientists at the Department of Energy’s Pacific Northwest National Laboratory, is the first to explore changes to snowmelt caused by soot pollution at a regional level. The study, authored by Qian, Gustafson, Leung and Ghan, is scheduled to be published next month in the Journal of Geophysical Research-Atmospheres.

The study found that particulate emissions from automobile tailpipes and industry smokestacks settles on snow-covered mountains and covers them with a dark layer that absorbs more sunlight and melts the snow faster.

more:

http://redgreenandblue.org/2009/01/28/air-pollution-now-melting-snowpack-quicker-study-shows/

[OKIsItJustMe]

1. Press Release Here

http://www.pnl.gov/news/release.asp?id=344

Release date: January 12, 2009
Contact: Mary Beckman, [phone]

Dirty snow causes early runoff in Cascades, Rockies

Part of the changing climate, earlier spring snowmelt could affect hydropower generation, agriculture

RICHLAND, Wash. – Soot from pollution causes winter snowpacks to warm, shrink and warm some more. This continuous cycle sends snowmelt streaming down mountains as much as a month early, a new study finds. How pollution affects a mountain range's natural water reservoirs is important for water resource managers in the western United States and Canada who plan for hydroelectricity generation, fisheries and farming.

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The soot-snow cycle starts when soot, a byproduct of burning fossil fuels, darkens snow it lands upon, which then absorbs more of the sun's energy than clean white snow. The resulting thinner snowpack reflects less sunlight back into the atmosphere and further warms the area, continuing the snowmelt cycle.

This study revealed regional changes to the snowpack caused by soot, whereas other studies looked at the uniform changes brought by higher air temperatures due to greenhouse gases.

Previous studies have also examined the effect of airborne or snowbound soot on global climate and temperatures. Qian and his colleagues at PNNL used a climate computer model to zoom in on the Rocky Mountain, Cascade, and other western United States mountain ranges. They modeled how soot from diesel engines, power plants and other sources affected snowpacks it landed on.

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