‘Killer clouds’ photographed over Norway
In a town where the sun doesn’t rise for months, there are still spectacular sights to see in the sky. These dazzling photos from Truls Tiller of Tromsø, Norway show colorful, glowing phenomena known as polar stratospheric clouds.
“Here the sun is gone for now, but this beautiful view makes the winter and the dark months nice to be in as well,” Tiller wrote on Spaceweather.com.
“Virtually all the clouds we see occur in the troposphere, the lowest layer of the atmosphere extending up to about 12 miles above the ground,” weather.com senior meteorologist Jonathan Erdman said. “Polar stratospheric clouds form at a height of at least 70,000 feet, over double the altitude commercial airlines fly.”
These clouds are visible only in higher latitudes in the northern and southern hemispheres. The lack of sunlight in the polar regions mixed with extraordinarily cold temperatures in the stratosphere changes water vapor in the atmosphere to a supercooled liquid or ice crystals.
They’re rare, yes, but also dangerous. “They play an indirect role in the destruction of stratospheric ozone,” Erdman said. As it turns out, these clouds are the breeding grounds for chemical reactions that involve chemical compounds derived from chlorofluorocarbons (CFCs), releasing chlorine gas that kills the ozone in the atmosphere.
You can keep up with Tiller and his breathtaking photos from Norway on his Facebook page.