If you’ve been reading Strange Sounds for a long time, you had probably already seen all kind of amazing cloud formations looking like dragons, dogs and fluffy balls.
However, this time a totally crazy cloud has appeared in the sky over Caxias, Brazil on December 6, 2016. Just look at this video:
Here the original video published by Oliveira Oliver Lima on Facebook:
Such a phenomenon is known as cloud iridescence. Cloud iridescence is the occurrence of colors in a cloud similar to those seen in oil films on puddles, and is similar to irisation. It is a fairly uncommon phenomenon, most often observed in altocumulus, cirrocumulus, lenticular clouds and cirrus clouds. The colors are usually pastel, but can be very vivid.
Iridescent clouds are a diffraction phenomenon caused by small water droplets or small ice crystals individually scattering light. Larger ice crystals produce halos.
If parts of clouds have small droplets or crystals of similar size, their cumulative effect is seen as colors. The cloud must be optically thin, so that most rays encounter only a single droplet. Iridescence is therefore mostly seen at cloud edges or in semi-transparent clouds, and newly forming clouds produce the brightest and most colorful iridescence.
Just to crazy to be a natural cloud!