“Fire rainbows” may not involve actual fire or even be true rainbows, but their beauty is nothing short of breathtaking. These captivating natural wonders are scientifically known as iridescent clouds, a relatively rare atmospheric phenomenon resulting from clouds made up of water droplets of nearly uniform size. According to NASA, iridescent clouds create their dazzling display by diffracting or bending light, which then separates into different wavelengths and colors.
The resemblance between iridescent clouds and rainbow-colored glories is striking. Both are born from the principle of diffraction, producing a mesmerizing array of colors that shift from blue to green, red, purple, and back to blue, creating a stunning oscillating pattern.
However, it’s important to note that while they share the rainbow’s color spectrum, the process behind their formation differs slightly. Rainbows arise through refraction and reflection, where light is bent as it passes through varying mediums with different densities, such as water or prisms. Reflected light bounces off surfaces at angles matching its point of impact. In contrast, diffraction scatters light waves into a ring-like pattern.
Much like other iridescent objects, including peacock feathers, the colors displayed by iridescent clouds vary depending on one’s relative position to the sun and the object.
Iridescent cloud occurrences are typically associated with newly formed clouds, and this recent sighting in South Florida aligns with that pattern. According to the Weather Channel, these are pileus clouds created by a rapidly growing thunderstorm that pushed air into the upper atmosphere through a layer of moisture. This process resulted in the formation of a fog-like cloud resembling a radiant dome atop the thunderstorm.
It’s essential to differentiate iridescent clouds from circumhorizontal arcs, which manifest as bands of color running parallel to the horizon.
The mesmerizing photo capturing this fascinating natural event was taken on July 31 in the skies over South Florida, providing us with a glimpse into the enchanting world of “fire rainbows.”
