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Melt Mystery
Despite a large and growing interest in polar regions by scientists and the public, they are remarkably mysterious and difficult places to study.
Take the Arctic sea ice, for instance. It's been in the news a lot lately because over the years it's been covering less and less of the Arctic Ocean in summertime. The sea ice is shrinking and getting thinner as well. The latest study from the National Center for Atmospheric Research estimates that the Arctic Sea will have ice-free summers by the year 2040 because of global warming.
But the exact mechanism causing the melting of the ice is still up for grabs. Some researchers think it's warmer water moving up through the Bering Strait and melting the ice from below. Other scientists suspect a combination of air temperature and a vicious cycle of dark, open waters absorbing more solar energy than ice, and therefore perpetuating more open water. Either way, the situation is expected to accelerate as the ever thinner ice simply crumbles.
Megadune Mega-Mystery
Another mystery that's a lot less worrisome but nonetheless puzzling is the megadunes of Antarctica. Unlike dunes made from snow, the Antarctic megadunes are broad, undulating waves in the surface of an ice sheet. The dunes are 6.5 to 13 feet (2 to 4 meters) high and one to three miles (two to five kilometers) apart. They were first spotted by pilots, but satellite images revealed vast areas covered by the dunes — some as large as the entire state of California. The features are too large to be seen from the ground.
Scientists have tried to explain the dunes in various ways — including some strange atmospheric processes that sound more like they belong on Mars or Pluto than Earth. But since they are pretty hard to visit and even harder to see being made, no explanation has taken hold.
Climatic Canary
What polar researchers can say for certain is that the polar regions are feeling global warming more acutely than the rest of the world. Polar animals and plants that have evolved to live on ice or permafrost already feel the heat because their lifestyles depend on one critical number: 32 degrees F (0 degrees C). Above that number their way of life is threatened or nonexistent. As the global climate heats up, there will be fewer and fewer places for cold-region creatures to hide.
