The iridescent pileus cloud phenomenon, also known as a rainbow cloud, is a fascinating spectacle that captivates observers. This occurrence was notably captured in Puning City, Guangdong Province, China, where it garnered significant attention. These clouds, often described as cap clouds, are formed atop cumulus or cumulonimbus clouds. The rainbow-like effect they exhibit is a result of tiny ice crystals or water droplets in the air diffracting light. They typically form in alto-cumulus, lenticular, cirrus, and cirrocumulus clouds, and their lifespan is often brief.
Another captivating image of an iridescent pileus cloud was captured in Pu’er, China, demonstrating more evidence of this rare phenomenon. In this instance, the cloud was formed from uniformly sized water droplets that scattered different colors of sunlight, creating an arc of light above the cloud [3]. This spectacular display of nature’s beauty was captured by Jiaqi Sun and shared by APOD/NASA, highlighting the wonders of our natural world.
