Polar Stratospheric Clouds are composed of:
Nitric acid and water
Methane and oxygen
Carbon dioxide and nitrogen
Hydrogen and helium
Polar Stratospheric Clouds, also known as nacreous clouds, are composed of nitric acid and water. These clouds are found in the stratosphere, approximately 15 to 25 kilometers above the Earth's surface, in the polar regions. Nitric acid trihydrate crystals form in the clouds due to extremely cold temperatures, and when the sun rises, the clouds can appear to be iridescent.