The image nicely captures the visual impact of nacreous clouds. A darkling sky, intense bright electric colours, films slowly stretching and curling high above.



The 15-25 km high stratospheric clouds remain in sunshine after sunset on the ground. Their colours are from diffraction by the tiny ice crystals that compose them. These Type II polar stratospheric clouds are often embedded in less luminous and more noxious Type I PSCs of nitric and sulfuric acids. Type II cloud particles destroy stratospheric ozone by catalytic reactions on their surfaces.

