Which of the following cloud types is characteristically formed at very high altitudes and consists almost entirely of supercooled water droplets or ice crystals, often displaying a colorful iridescence known as nacreous clouds?

💡 Solution & Explanation

Polar stratospheric clouds, frequently called nacreous clouds, form in the extremely cold winter polar stratosphere at high altitudes of fifteen to twenty-five kilometers and consist of supercooled water or nitric acid ice crystals. They differ from low-altitude stratocumulus or mid-level lenticular clouds by displaying striking iridescent pearl-like colors due to the diffraction of sunlight. These high-altitude formations play a critical chemical role in facilitating polar ozone destruction.