Wairarapa was treated to a meteorological phenomenon yesterday afternoon when a halo surrounded the sun.
According to witnesses, it started to be seen in the sky at about 2pm, and lasted nearly an hour.
A sun halo – also known as a 22 degrees halo – forms when sunlight is refracted through the tiny ice crystals of thin, wispy high cloud, MetService meteorologist Thapi Makgabutlane explained.
“One explanation is that because of the hexagonal shape of these ice crystals, the light is refracted as it enters one face of the crystal, then is refracted again as it exits another face. Oftentimes, the inner edge of the halo appears to have a red tinge since different colours of light refract at slightly different angles.”
“It’s like the aliens are coming”, one Masterton resident said.
Akash Patel, who was quick to take a photograph, was initially astounded.
“My first thought was, ‘What the heck is that?’ Once I’d taken the photo, my next thoughts were about connection and how everything is connected in the universe, just like people with different cultures are connected.”
According to the MetService blog, “the sun halo is just one phenomenon amongst a broad range of atmospheric optical phenomena that occur when sunlight is refracted and reflected through ice crystals, in clouds high up in the atmosphere.”
But while an impressive sight, sun halos are “not an especially rare occurrence”, Makgabutlane said.
“But that hopefully doesn’t take anything away from Akash’s awesome photograph.”
Other atmospheric optical phenomena that can occur in New Zealand skies are the more common rainbow, crepuscular rays [sometimes called God rays or Jacob’s ladder], fogbows [which are colourless], circumzenithal arcs and sun dogs.
Sun dogs are a type of sun halo usually seen when the sun is low in the sky, MetService said. “They occur in pairs, directly to the left and right of the sun, though whether or not you can see both sun dogs in the pair depends on the extent of the icy cirrus cloud. If you’re lucky, you may see a pair of sun dogs on the edge of a 22 degrees halo, level with the sun.”
