How do you keep a cold city cool during the summer? Mongolia's capital city — , its average temperature at the peak of summer is 72 degrees Fahrenheit — has an idea that sounds adventurous.
During the cold months, the city of Ulan Bator wants to create artificial glaciers that will then melt slowly during summer, absorbing some of the heat and helping to keep the temperatures down. Here's how Wired explains the process in their piece today:
"The aim is to build artificial ice shields — or "naleds" — that occur naturally in far northern climates and can grow to be more than seven meters thick. They grow when river water pushes through cracks in the surface of the ice during the day and then freezes to add an extra layer of ice when night falls.
"Engineering consortium EMI-ECOS will try to replicate this process by creating holes in the ice that is forming over the Tuul river. This will be repeated over and over again until the ice is much thicker than it would be if left alone."
The Guardian, which first reported the story, yesterday, says the city also expects for this process to regulate drinking water. The Guardian adds:
The qualities of naleds (also known as Aufeis, German for "ice on top")have been known for hundreds of years. The North Korean military used them to build river crossings for tanks during the winter and Russia has used them as drilling platforms. But engineers usually see them in negative terms as a threat to railways and bridges.
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"Everyone is panicking about melting glaciers and icecaps, but nobody has yet found a cheap, environmentally friendly alternative," said Robin Grayson, a Mongolian-based geologist. "If you know how to manipulate them, naled ice shields can repair permafrost and building cool parks in cities." He said the process will work in cities where the summer is intolerably hot and winters have at least a couple of months with temperatures of -5C to -20C.
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