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Reindeer
Tue Dec 16, 2003
Listen in RealAudio 
Hi, I'm Bryan Yeaton, and this is The Weather Notebook's weekly segment on Global Climate
Change. A foggy Christmas Eve kept Santa's reindeer grounded, at least until Rudolph came to
the rescue.
But, when it comes to earthbound reindeer, there's a much more serious weather threat. Rain on
top of snow affects reindeer, as well as caribou, elk, and other ungulates throughout the far
north. And climate change could make things worse.
Ungulates feed in the winter by burrowing through deep snow to nibble on moss and lichen
growing atop the frozen soil. Sometimes a warm, wet air mass sweeps in and drops winter rain
on a snow pack three feet or more deep. The raindrops percolate through the snow to the soil.
As they freeze on the ground, they release heat, but that heat is trapped between the frozen
ground and the snow on top. As a result, the soil surface warms to near freezing, then gets
coated with ice that can last until spring. The ungulates can't break through the ice to get
at their food, and the humid warmth also nurtures fungi and mold that the animals avoid.
Ecologists have found mass die-offs due to rain-on-snow events across Norway, Scandinavia,
Russia, Canada, and Greenland. Now, two scientists at the University of Washington have
combined observations with a climate model extending 80 years out. Their work shows a
potential 40 percent increase in the area that gets big rain-on-snow events. By the year
2080, more than 5 million square miles could be affected each year, from Alaska to Scandinavia
to Russia. This could spell major trouble for creatures who'd rather just let it
snow.
Today's show came from Bob Henson. Our Climate Change series is supported by the New England
Science Center Collaborative. We are also supported by Subaru and The National Science
Foundation.
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