If you have ever seen nacreous clouds, you will remember them for life

Around the Arctic circle unfolds an impressive outbreak of polar stratospheric or nacreous, clouds.

"This only happens once in a lifetime. Without a doubt, this is the best we have ever seen," says Chad Black, head of tourist service Lights over Lapland in Abisko, Sweden.

In the video, filmed guide Paige Ellis on December 29, the clouds are colorful, which is similar to the Aurora.

"They were so intense that many tourists thought that I was on the daily Aurora. I had to explain that actually are clouds in the stratosphere," says Black.

As a rule, in the stratosphere, contains the ozone layer, no clouds, it is dry and almost always transparent. Only when the temperature drops to -85 °C, water molecules can gather in the icy stratospheric clouds. These clouds are formed much less frequently than the Aurora.

"Locals in Abisko and Kiruna, which is more than 70 years, confirmed that never saw the pearlescent clouds of this size, scale or intensity. At some point, about 25 % of the sky was filled with clouds. In the previous winter — just 1-2%, " — said Black.

The flash lasted 30 Dec. "Today, I saw some of the brightest clouds in all my years of observations," — said Goran strand, sent a photo of the Jämtland County, Sweden.

"They were so bright that even covered the landscape", — he was surprised.

Nacreous clouds are very bright, because they consist of ice. High-altitude sunlight, penetrating through microscopic crystals with a diameter of only 10 microns, produces a bright iridescent glow that no ordinary tropospheric clouds.

Translated by «Yandex.Translator»