@science_explanation.14 on Instagram: "Polar stratospheric clouds (PSCs), also known as nacreous clouds, form in the winter polar stratosphere at altitudes of 15 to 25 kilometers. They occur at extremely low temperatures, around -78°C or colder. Unlike typical clouds, PSCs are composed of ice crystals and supercooled droplets of nitric acid and water. These clouds play a critical role in the depletion of the ozone layer by providing a surface for chemical reactions that release chlorine and brom