Bengaluru witnesses rare atmospheric phenomenon 'Sun Halo'

Bengaluru: India's tech hub witnessed an optical phenomenon - Sun Halo or a rainbow-coloured ring around the sun across Bengaluru on Monday, which brightened up the day with several people on social media sharing pictures and funny captions with it. Bengaluru residents were left awed by the rainbow-coloured halo surrounding the sun as the striking circular rainbow ring was reportedly visible from most parts of the capital of Karnataka.

It was first seen around 11 a.m. and lasted for over an hour, in which time Bengaluru residents flooded social media with pixtures of the rare phenomenon.

@MyGovIndia summed up the euphoria surrounding the sun and the sombre mood amidst Covid times by stating in its tweet that "Amidst such challenging times of #COVID19, this majestic optical phenomenon #SunHalo, witnessed across #Bengaluru, definitely brightened up the day!"

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 which happen to have the right orientation and angular position to direct their refracted light into your eye.

The website added that the key is still crystal orientation and only those crystals with their prism axes roughly perpendicular to the sun's rays allow light to pass through two side faces.

Halos around the sun are caused by the refraction or the splitting of sunlight by ice crystals in the atmosphere. Circular halos specifically are produced by cirrus clouds, which are thin, detached, hair like clouds. These clouds are formed very high up in the atmosphere, at a height of over 20,000 feet.

Just like a rainbow, a halo is visible when viewed from the right angle - sometimes appearing just white but often with colours of the spectrum also clearly present.

Such a halo could also occur around the moon at night, which is formed due to the same phenomenon.

Delighted Bengaluru residents took to social media to share photos of the rainbow-coloured ring. P. C. Mohan, Lok Sabha member from Bengaluru Central constituency, shared three photos of the 'stunning sun halo' on Twitter.

Another person joked on Twitter that even the sun is social distancing.

Although the phenomenon is rare, it is not unheard of. Some Twitter users dug up old photographs of sun halos, as seen before in other parts of the country.

"Such Sun or Moon halos are not so common however they have been witnessed earlier in the country in the past," tweeted senior IFS officer Ramesh Pandey.

Sun Halo, also known as '22 degree halo', is an optical phenomenon that occurs due to sunlight refracting in millions of hexagonal ice crystals suspended in the atmosphere. It takes the form of a ring with a radius of approximately 22 degrees around the sun or the moon. (IANS)