Have you ever seen a rainbow in the sky that is so vivid and colorful that it looks like it was on fire? If you have, then you may have seen a phenomenon known as a fire rainbow. Fire rainbows are not actually rainbows, nor do they contain any fire. They are instead an optical phenomenon caused by refraction of light from ice crystals in the atmosphere.
Fire rainbows get their name from their appearance, which is strikingly similar to that of a real rainbow. The clouds appear to be on fire with vibrant and intense colors radiating throughout the sky. The spectrum of colors can range from oranges, reds and yellows to blues, violets and greens. Fire rainbows can also appear as a full 360 degree arch in the sky with some parts appearing brighter than others.
The scientific explanation behind this phenomenon is qite complex but essentially what happens is sunlight reflecting off of plate-shaped ice crystals refracts the light into its constituent colors creating the rainbow effect at certain angles. In order for a fire rainbow to form, these two conditions must be met: cirrus clouds containing hexagonal ice crystals must be present and the sun must be relatively high in the sky (58° or more). As such, fire rainbows are most likely to occur during mid-latitude summer months when the sun is at its highest point in the sky.
Unfortunately, due to their rarity and specific location requirements you won’t get to see them very often; they usually only appear several times each year at most locations in the United States and even less often elsewhere throughout the world. If you do happen to witness this incredible sight make sure to take a picture or video because it will surely take your breath away!
How Uncommon Is a Fire Rainbow?
A fire rainbow, also known as a circumhorizontal arc, is considered to be a very rare atmospheric phenomenon. It is caused by the light of the sun reflecting and refracting off of high level ice crystals in cirrus clouds. It is only visible when the sun is very high in the sky (higher than 58° above the horizon) and when there are the right types of ice crystals present at an altitude between 20,000 – 25,000 feet. These conditions only occur dring certain times of the year in certain areas, making sightings of a fire rainbow relatively uncommon. Additionally, due to its relatively faint appearance compared to other halos, it can be difficult to detect even when conditions are favorable.
Source: cloudatlas.wmo.int
Formation of a Fire Rainbow
A fire rainbow is a unique phenomenon that occurs when the sun’s light is refracted off of plate-shaped ice crystals in cirrus clouds. To form a fire rainbow, the sun must be at leat 58 degrees above the horizon and the cirrus clouds must contain hexagonal ice crystals. As the sun’s light passes through these ice crystals, it is refracted and split into its component colors, resulting in an arc of vibrant colors across the sky resembling a rainbow. Depending on the angle of sunlight, this arc may appear as an entire semicircle or even as an entire circle. The order of colors seen in a fire rainbow are typically red on the outside and blue on the inside, though other colors may also be visible depending on atmospheric conditions. Fire rainbows are very rare and can only be seen for a few minutes at most before disappearing.
The Meaning of a Fire Rainbow
When you see a fire rainbow, it means that you have likely witnessed the rare phenomenon of iridescent clouds. This phenomenon is caused by sunlight reflecting off of plate-shaped ice crystals in high-level clouds, such as cirrus clouds, to create a colorful arc. The colors seen in the arc range from pink and red to blue and purple, but they tend to appear more vibrant than a traditional rainbow. While these iridescent clouds are commonly referred to as fire rainbows, they are not technically true rainbows as they are not caused by rain or fire.
Frequency of Fire Rainbows
Fire rainbows, also known as circumhorizontal arcs, are most common in mid-latitudes and near the equator. They can be seen from late March to late September, making them a seasonal phenomenon. In the United States they tend to appear several times a year in regions between 40°N and 40°S latitude. Fire rainbows are not seen in places north of 55°N or south of 55°S.
In addition to apearing in mid-latitudes and near the equator, fire rainbows can be seen more frequently in mountainous regions with high altitudes that have plenty of ice particles suspended in the atmosphere. The higher altitude means more ice particles, which creates the perfect conditions for a fire rainbow to form.
If you’re looking to see a fire rainbow, it’s important to pay attention to weather forecasts for your area and look out for conditions such as high humidity and cirrus clouds (made up of ice crystals). If all these conditions align, you may just get lucky enough to witness a stunning fire rainbow!
Source: commons.wikimedia.org
Can Fire Rainbows Be Seen at Night?
No, fire rainbows cannot be seen at night since they require sunlight to be present in order to form. Because they are created by the refraction of light from ice crystals in the atmosphere, these ice crystals need direct sunlight to cause the rainbow-like effect. Therefore, fire rainbows can only be seen during the day when the Sun is at least 58o above the horizon.
Viewing a Fire Rainbow
A fire rainbow, also known as a circumhorizontal arc, is an incredibly rare and beautiful phenomenon that can be seen in certain types of clouds at high altitudes. Specifically, this phenomenon can be seen in cirrus or cirrostratus clouds. These wispy, thin clouds occur between 16,500 feet and 45,000 feet for cirrus clouds, and 18,000 and 21,000 feet for cirrostratus clouds.
The fire rainbow occurs when the sun is high enough in the sky to cause light to refract off of ice crystals in the atmosphere. This causes a beautiful spectrum of colors to appear in the sky. It is most often seen around midday when the sun is highest in the sky and can last up to several hours. Unfortunately, this phenomenon is quite rare due to its infrequent occurrence undr specific conditions.
Source: flickr.com
Conclusion
In conclusion, fire rainbows, or circumhorizontal arcs, are an amazing natural phenomenon that can be seen in certain locations around the world. They are created by the refraction of sunlight through hexagonal ice crystals in cirrus clouds, and can apear several times a year from late March to late September in mid-latitudes and close to the equator. Fire rainbows are not true rainbows and have nothing to do with fire; instead they are iridescent clouds that create a spectacular show of color in the sky. Although they are quite common in the US, they are a rare sight in northern Europe due to more stringent weather conditions. All in all, fire rainbows offer an incredible spectacle of nature’s beauty that should be appreciated.
