Nacreous clouds, or ice polar stratospheric clouds, are a rare type of cloud that forms in very cold conditions and at high altitudes.
Nacreous clouds are found during the winter in high-latitude areas, including the Arctic, Scotland, Scandinavia and Alaska. They sometimes form over other areas of Northern Europe but are the most common in Antarctica. Some nacreous clouds are wave clouds, which often form near mountain ranges.aurora borealis, or northern lights
Nacreous clouds are also called Type II polar stratospheric clouds , which are clouds that form in the winter polar stratosphere.
Though nacreous clouds aren't directly hazardous to humans, PSCs enhance the breakdown of Earth's ozone layer, a part of the atmosphere that protects us from the sun's ultraviolet radiation, according to The Conversation. However, some evidence suggests that Type I PSCs are more of a threat, according to. Chemicals in the ice crystals, such as chlorine and bromine, react with ozone-destroying substances in the atmosphere, thus accelerating its destruction.