There are a lot of things happening around the world. You might have heard about crown flashes looking like signals from aliens wanting to communicate with us. And now, there are these fire rainbows appearing in the sky.
That is what a fire rainbow looks like. It may look like a rainbow that did not form well. It also looks like a really colourful fire.
As weird as it may be, it’s neither fire nor a rainbow. They are just called fire rainbows because of its colours and its flame-like appearance. Technically speaking, they are called circumhorizontal arcs. It’s an ice halo which formed due to the hexagonal, plate shaped ice crystals in high altitude cirrus clouds. The halo it forms is so large that its arc appears to be parallel with the horizon – giving it the name circumhorizontal arc.
This strange phenomenon happens mostly in summer and in certain latitudes. As the sun gets really high in the sky, sunlight hits the hexagonal, plate shaped ice crystals and then splits into different colours just like a prism.
In order for a fire rainbow to form, the sun should be elevated to as much as 58° or more. High altitude cirrus clouds with plate shaped ice crystals should also be present. If that happens, sunlight should also hit the ice crystals at a specific angle. If it forms, a person who wants to see it should also be in the perfect spot. These arcs cannot be seen north of 55° N and south of 55° S.
As it’s really rare to see one, make sure you capture a photo of it when you spot one in the sky.