Hyderabad residents were in for a pleasant surprise on Wednesday (June 2) when a rare sun halo was seen in the sky. Also known as the "22-degree circular Halo", it is an unusual optical solar spectacle that happens when the sun's or moon's rays get refracted/deflected through the hexagonal ice crystals in the cirrus cloud. This is also known as the Kaleidoscopic Effect. When visible around the Moon, it is called a moon ring or winter halo.
Last month, Bengaluru city witnessed this rare Sun Halo phenomenon on May 24. The rainbow-coloured halo surrounding the sun as the striking circular rainbow ring was reportedly visible from most parts of the capital of Karnataka.
According to the UK-based Atmospheric Optics, a knowledge-sharing website, the Halo phenomena happens when the light is reflected and refracted by ice crystals and may split into colours because of dispersion.
"The crystals behave like prisms and mirrors, refracting and reflecting light between their faces, sending shafts of light in particular directions. Atmospheric optical phenomena like halos were used as part of weather lore, which was an empirical means of weather forecasting before meteorology was developed. They often do indicate that rain will fall within the next 24 hours, since the cirrostratus clouds that cause them can signify an approaching frontal system," Atmospheric Optics explained.
The website stated that Halos are the collective glints of millions of crystals that happen to have the right orientation and angular position to direct their refracted light into your eye.
