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Mountain Snow is Endangered
http://www.sciencedaily.com/releases/2006/05/060519102250.htm



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2 SAMPLE QUOTES : "The decline in winter snowpack means less spring
and summer runoff from snowmelt. That translates to unprecedented
pressure on people worldwide who depend on summertime melting of the
winter snowpack for irrigation and drinking water."

"Hardest hit are mountains in temperate zones where temperatures
remain freezing only at increasingly higher elevations, said Steven
J. Ghan, staff scientist at the Department of Energy's Pacific
Northwest National Laboratory and lead author of a study describing
the model in the current Journal of Climate."
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SCIENCE DAILY
MAY 19, 2006
http://www.sciencedaily.com/releases/2006/05/060519102250.htm

Source: Pacific Northwest National Laboratory

Posted: May 19, 2006

New Century Of Thirst For World's Mountains

By the century's end, the Andes in South America will have less than
half their current winter snowpack, mountain ranges in Europe and the
U.S. West will have lost nearly half of their snow-bound water, and
snow on New Zealand's picturesque snowcapped peaks will all but have
vanished.

Such is the dramatic forecast from a new, full-century model that
offers detail its authors call "an unprecedented picture of climate
change." The decline in winter snowpack means less spring and summer
runoff from snowmelt. That translates to unprecedented pressure on
people worldwide who depend on summertime melting of the winter
snowpack for irrigation and drinking water.

Hardest hit are mountains in temperate zones where temperatures
remain freezing only at increasingly higher elevations, said Steven
J. Ghan, staff scientist at the Department of Energy's Pacific
Northwest National Laboratory and lead author of a study describing
the model in the current Journal of Climate. PNNL scientist Timothy
Shippert was co-author.

Alaska in 2100 will maintain but 64 percent of its year 2000
snowpack. In Europe, the Alps will be at 61 percent and Scandinavia
56 percent. The Sierras, Cascades and southern Rockies will be at 57
percent of current levels. The Andes will drop to 45. And Mt. Cook
and its snowcapped neighbors in New Zealand will be much less scenic
at 16 percent of current.

Ghan said the model, which actually simulated years 1977 to 2100 to
use known data as calibration, differs from past attempts because it
generates snow information for small areas -- 5 kilometer grids, or
about 3-miles -- on mountains ranges over such a long period.

"Global climate models have never been run at 5 kilometers resolution
for a period covering more than a couple of months," Ghan said, "even
on the biggest computers in the world."

Ghan deployed a divide-and-conquer method to data crunching called
"physically-based global downscaling" he and colleagues had used
previously on mountains in the U.S. West. The world's mountain ranges
are chopped into 10 different "elevation classes." For each elevation
class, data such as air circulation, moisture and temperature is used
to determine snowfall to the surface. The surface snow is then
distributed across the grids according to the local surface elevation.

The entire century-plus simulation, based on the National Center for
Atmospheric Research Community Climate System Model funded by the
National Science Foundation and DOE, can be run on a modest
supercomputer over a few weeks. Ghan and Shippert used one at the
PNNL-based W.R. Wiley Environmental Molecular Sciences Laboratory.

Ghan cautioned about "significant limitations" to the model. For
example, field observations in Africa suggest the famous snows of Mt.
Kilimanjaro will be gone within decades, and on Greenland signs point
to accelerated snow and ice melt.

"This climate model doesn't show that," Ghan said. "That doesn't mean
Kilimanjaro and Greenland aren't in trouble. But our model doesn't
account for all of the snow loss that is possible. Our model neglects
downward flow of snow by avalanches and snow slides, glacial creep in
places where snowfall is heavy and the snow doesn't have time to
melt."

Editor's Note: The original news release can be found here.
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Contact: editor@sciencedaily.com

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