Technically called a circumhorizontal arc, fire rainbows are caused by light passing through wispy, high-altitude cirrus clouds. This one was seen over South Carolina Monday for about an hour. It was photographed and uploaded to Instagram.
This phenomenon also produces a rainbow effect, but through diffraction rather than refraction. Though not traditionally seen as a sign of good luck like your average rainbow, fire rainbows are certainly a rare sight and worthy of sharing. In many Eastern cultures, they’re even viewed as a symbol of transformation.
As mentioned above, fire rainbows are rare. The source of light—the Sun (or Moon)—needs to be at least 58o above the horizon, meaning that fire rainbow is almost impossible to see in places north of 55oN or south of 55oS. Also, in places where it is spotted, its frequency of occurrence and duration varies widely.
A rainbow cloud can occur because of something called cloud iridescence. It usually happens in altocumulus, cirrocumulus, lenticular and cirrus clouds. Iridescent clouds happen because of diffraction – a phenomenon that occurs when small water droplets or small ice crystals scatter the sun’s light.
Images of the iridescent clouds went viral, but scientists say “fire rainbow” is a misnomer: the phenomenon is not a true rainbow, and it has nothing to do with fire – instead of rain or flame, the phenomenon is caused by ice.
Fire rainbows can’t be seen in places north of 55°N or south of 55°S. The best location to watch this phenomenon is mid-latitudes and close to the equator. In the US circumhorizontal arcs are quite common can appear several times a year from late March till late September.
But there is a difference. Fire Rainbow: Most common in the middle of the day (late morning to early afternoon). Often a streak of color that might appear flat and below in relation to the sun. Sun Dog: Most common later in the afternoon when the sun is lower in the sky.
How often a circumhorizontal arc is seen depends on the location and the latitude of the observer. In the United States it is a relatively common halo, seen several times each summer in any one place. In contrast, it is a rare phenomenon in northern Europe for several reasons.
In short, you can touch someone else’s rainbow, but not your own. A rainbow is light reflecting and refracting off water particles in the air, such as rain or mist. The water particles and refracted light that form the rainbow you see can be miles away and are too distant to touch.
According to NASA, circumhorizontal arcs are only visible cirrus clouds are present and the Sun is at least 58 degrees high in the sky. The circumhorizontal arc cannot be observed north of latitude 55° North and south of of latitude 55° South since the Sun is always lower than 58°.
This type of rainbow is known as a circumhorizontal arc. The physics behind how these horizontal rainbows form is quite different than that of the typical rainbow. This optical phenomenon is brought on by the way in which light passes through suspended ice crystals in the atmosphere.
Hope. After every rain, there’s the sun, and if the two occur simultaneously, there’s a hope for a rainbow or even the double rainbow. Even when people lose faith in some things happening, there’s always hope. The hope dies the last, so it’s the last resort many people opt to believe in when life gets hard.
One of the main ways a rainbow can form without any rain is called virga. The rainbow formed due to rain but the rain evaporated before it hit the ground.
They are not only rare to see — they are a puzzle to understand. The common rainbow is caused by sunlight internally reflected by the backs of falling raindrops, while also being refracted at the air/water boundary. The sunlight in this picture is coming from behind the observer, and the rainbows are in the rainstorm.
“Fire Rainbows” are actually neither fire, nor rainbows. They are called so because of their bright colors and flame like appearance. They are known as a Circumhorizontal Arc, which is an ice halo formed by hexagonal plate-shaped ice crystals located in high level cirrus clouds.
Meet ‘Firebows,’ the Flat, Rainbow-Like Stacks That Appear in Sunny Skies.
A vertical rainbow, as photographed by Janet Pierucci.
Jeanne Jackson • April 25, 2020. Janet Pierucci noticed this gorgeous site, a vertical rainbow, also called a Sun Dog or a Parhelion. A Sun Dog is a rainbow in the sky but there are no rain clouds. It is formed when light rays pass through high cirrus clouds.
A moonbow (sometimes known as a lunar rainbow) is an optical phenomenon caused when the light from the moon is refracted through water droplets in the air. The amount of light available even from the brightest full moon is far less than that produced by the sun so moonbows are incredibly faint and very rarely seen.
Rainbows form when drops of rain act as prisms, breaking sunlight into a multitude of colors. Sundogs appear when sunlight passes through a thin veil of ice crystal clouds (usually cirrus or cirrostratus) and the ice acts a prism, refracting the light.
Despite their beauty, sundogs are indicative of foul weather, just like their halo cousins. Since the clouds that cause them (cirrus and cirrostratus) can signify an approaching weather system, sundogs themselves often indicate that rain will fall within the next 24 hours. Means, Tiffany.
Sundogs are colored spots of light that develop due to the refraction of light through ice crystals. They are located approximately 22 degrees either left, right, or both, from the sun, depending on where the ice crystals are present.
According to the National Weather Service, sundogs form when sunlight refracts off ice crystals in the atmosphere and result in colored spots of light approximately 22 degrees either left, right, or both, from the sun.
(WSFA) - If you saw what looks like a rainbow on clouds Tuesday afternoon, you were looking a rare optical phenomenon called a circumhorizontal arc. Yes, that’s a very real and scientific term! You may have seen one of these before and referred to it by its other name – a “fire rainbow.”
The circumhorizontal arc occurs only when the elevation of the light source is more than 58°. When the Sun reaches an elevation of about 68°, the circumhorizontal arc reaches its maximum intensity.