We've already realized that nature is incredible and can show us extraordinary and beautiful phenomena and events. In this case, we're talking about a phenomenon that occurs in the atmosphere known as a fire rainbow . Although this name is somewhat misleading, it's a relatively common phenomenon in the skies that creates quite spectacular mosaics. It's also known as circumhorizontal arcs, a name that's more accurate than it actually is. The mosaics they form are incredibly colorful. However, the question many people ask is, how do they form, and why?
Well, in this article we are going to unravel all the secrets of the rainbow of fire. We will explain how it is formed and for what reason.
Key features
Although it resembles a common rainbow, it's not similar in its formation or origin. You may have seen it more than once in your life. These are spectacular bands of different but similar colors to those of a conventional rainbow . These colors are projected by the light transmitted through cirrus clouds . This creates a kind of projection of colors around a chromatic amalgam that filters through the clouds.
If you ever manage to observe this phenomenon directly and photograph it, you'll probably get better pictures than with a traditional rainbow. Although it doesn't form in the same way as a true rainbow and doesn't resemble one, it's called a fire rainbow because it occurs on very dry days. It does share some similarities in its color composition and its occurrence on drier days. The only difference is that it doesn't need rain to appear. Its effect and appearance are that of an incandescent flame seen through the prism of transparent clouds.
Cause of the rainbow of fire
We're going to explain step by step the reasons and causes of the formation of fire rainbows. These circumhorizontal arcs originate from cirrus clouds. Halos are common in our daily lives and create beautiful scenes in our skies. They are illuminated circles, sometimes of different colors, that surround the sun or moon in some latitudes. On these occasions, they can be seen with a visual corona whose interior is darker than the surrounding sky. These halos are formed by different plays of light within the natural phenomena.
Well, when we add the colors of the rainbow to a conventional halo and subtract the blinding effect of the sun or moon, we can obtain a circumhorizontal arc, also known as a fire rainbow. This phenomenon can be easily observed at any time since the sun isn't there to block direct view. We know that looking at the sun or its surroundings for extended periods can be harmful to our retinas. There are cases of people who have gone completely blind from staring at the sun for too long.
This multicolored band forms at high altitudes, and we need some absolutely essential conditions. First, the sun must be about 58 degrees above the horizon. We also need a good amount of cirrus clouds in the sky to scatter the light. These clouds are found at about 8 km altitude and spread out in long, narrow lines. Thanks to these clouds, landscapes of white streaks against the deep blue background are created. If we add the colors of the rainbow to this beautiful landscape, we have something truly incredible.
Nature of cirrus clouds
To explain the difference between a conventional rainbow and a fire rainbow, the nature of cirrus clouds is fundamental. While the former results from the reflection of sunlight off raindrops still suspended in the atmosphere, circumhorizontal rainbows require dry weather. This dry weather is necessary because tiny hexagonal ice particles, hidden within the cirrus clouds, are required. Therefore, understanding the shape and nature of these clouds is crucial.
It is thanks to the shape of these tiny ice crystals that sunlight can reflect and spread through cirrus clouds, forming long arcs of color. Sometimes, these arcs are so long that they can extend across the entire field of vision from our position. The formation is quite strange and unique for the following reason. In addition to everything we've already mentioned, there's one more factor: the ice particles must be in an almost horizontal position relative to the sun's rays. Otherwise, there would be no way for this light to extend through the cirrus clouds.
This means that, the vast majority of times we see a rainbow of fire, its duration is very short. These demanding conditions only exist for a time. The sun continues to set and the angle with the ice crystals is no longer the same as to reflect it.
Where can you see rainbows of fire
Now that we have analyzed the training and the reason for it, we are going to explain in which areas of the world and at what time they tend to be more frequent. To see it you need a place with a dry climate and where the sun is 58 degrees or below. If you go to the Nordic countries, you will rarely get to see one of these in full splendor.
One of the best cities to see this is Mexico City or Houston . In Spain, we have bad news: we're too far north to see them.
I hope this information serves to learn more about the rainbow of fire.
