A mysterious cloud appeared in China

'Pileus cloud', also known as a ‘cap cloud and ’scarf cloud'. According to The Weather Network, a pileus is formed when the rapidly rising air in the updraft of a towering cumulus cloud (also called a cumulonimbus) pushes against the cooler air above it. This causes condensation of the moisture right along the top of the updraft, leading to the formation of the Pileus.

When the sunlight is at the right angle, diffraction of light takes place between the droplets and ice crystals in the cloud, giving the Pileus its colours, which resemble those in a rainbow.

However, such clouds generally have a very short life. This is because these get ‘eaten up' by the cloud on top of which they appear; the lower cloud rises up through convection to absorb Pileus.