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| -Signs, Portents, and the Weather- |
| Alaska Solves Warming Problems |
| 2009-12-08 |
| While the world debates the causes of climate change and what, if anything, to do about it, Alaskans are busy dealing with its consequences. Can the left blame Sarah? Permafrost, the frozen ground that lies just beneath the surface in most of the state, has become less stable in many areas, thanks in part to higher average air temperatures. It has begun to thaw in the warmer months and refreeze in the winter, causing shifts that wreak havoc on the structural integrity of the pipelines, railways, roads and buildings that sit on top of it. This is not the first time I've read about this problem. Alaska Paul? "If we're going to build on frozen ground, we want to keep it frozen," says Dan White, director of the Institute of Northern Engineering at the University of Alaska Fairbanks. That's where thermosiphons come in. The device essentially is a tube filled with gas that can't escape. Part of the tube is buried in the ground, with the top exposed in the air. As temperatures plunge in the winter, the gas condenses into a liquid and falls to the bottom of the tube. The relative warmth of the ground then causes the liquid to evaporate back into gas that rises to the top of the tube, where the heat it carries is dissipated into the air. The cycle keeps repeating itself, with no need for any kind of power source or any intervention other than maintenance. Scientists say the process cools the ground around a tube so much during the winter that it stays frozen even in summer. Thermosiphons have been around in the Arctic for about 50 years. For most of that time they weren't used much outside of large infrastructure projects like the Trans-Alaska Pipeline, which is outfitted with about 120,000 of them. |
| Posted by:Bobby |
| #1 Excellent local solution, or as Al Franken's alter ego, Stuart Smalley, would say "It's easier to put on slippers than to carpet the entire world." |
| Posted by: tipper 2009-12-08 10:59 |