One of the unusual, fantastically beautiful and at the same time extremely rare natural phenomena is considered a fire rainbow. So scientists christened the atmospheric phenomenon - a near-horizontal (or round-horizontal) arc that appears against the background of light high-altitude clouds consisting of ice crystals. This atmospheric radiance occurs spontaneously - unlike a normal rainbow, it does not rain before a fiery one.
Factors of the appearance of a fiery rainbow in the sky
Rare lucky people on Earth manage to observe this unique natural phenomenon. How is a fire rainbow formed and what serves as its harbinger? One of the main factors in the occurrence of a circular horizontal arc is the geographical location - latitudes of the northern and southern hemispheres, located no further than 55 degrees from the equator. Another important condition, scientists call the presence of cirrus clouds - whiskers of snow-white inhabitants of the upper layers of the troposphere, freely transmitting sunlight. Ice crystals, from which cirrus clouds form, should take a horizontal position with respect to the ground. The daylight is usually located high in the sky, at a distance of 6, 000 km and above.
Sophisticated Fantasy of Mother Nature
The magic of the appearance of amazing color flicker in the sky is surprisingly simple. In summer, the bright glow of cirrus clouds is caused by the refraction of sunlight. In order for a fiery rainbow to occur, the rays of the sun must be oriented at an angle of 58 degrees relative to the horizon. They penetrate the side wall of each ice crystal of a hexagonal shape and continue their path through its lower face. In chains consisting of frozen hexahedrons, the sun's rays “run through” all the facets of the natural structure, to the last ice, and “carve out” the fire. The peak of brightness of this unusual natural phenomenon, according to meteorologists, can be observed when the sun shines on cirrus clouds at an angle of 68-69 degrees. This optical effect allows you to divide the light into spectral colors and visually obtain such an amazing phenomenon as a fiery rainbow. It can stretch for hundreds of square kilometers! Its halo is so large that the arc seems to be parallel to the horizon.
