Stratospheric nacreous clouds in the sky over Norway

The stratosphere over the Arctic circle will be cold... very cold. This is the only way to explain these colored clouds that formed over the island of Kvaloya in Norway 20 Dec.

For the formation of polar stratospheric clouds, also called mother-of-pearl, requires a temperature of -85 ºC.

"This morning met with residents of the city of Tromso in Northern Norway thick rain clouds and strong winds. But suddenly the gray clouds parted, and they seemed fantastic stratospheric clouds. Rarely have I seen them so colorful as today," said photographer Fredrik Broms.

The stratosphere is extremely dry, which hampers the formation of clouds of any type. Only when the air becomes very cold, the water molecules join to form the ice crystals that make up the stratospheric clouds. High-altitude sunlight, piercing the ice particles, creating the characteristic bright iridescent colors.

Translated by «Yandex.Translator»