Johannesburg sun halo explained
2010-11-01 11:21
Duncan Alfreds, News24
Cape Town - Residents of Johannesburg are transfixed by a halo which appears to be circling the sun.
"Could you possibly explain the bright circle/line around the sun right now?" said News24 user Charmaine.
"There's a very weird dark circle with a sort of rainbow around the sun in Jhb at the moment???" said another user.
These halos are caused when light from the sun refracts through ice crystals high in the atmosphere. Depending on the size of the crystals, the colour of the halo differs and they can also form around the moon.
"It has no implications for weather at all, I don't know about the folklore, but for us, nothing," Arno Dyason, weather forecaster at the SA Weather Service told News24.
Uncommon
He said that cirrus clouds drifting in from Botswana had contributed to the phenomenon and that it was quite uncommon in Gauteng.
"It's very uncommon here in Gauteng. I've spoken to some people on the phone and they say it's the first time they've seen it in a life time. It's more common in the Cape," he said.
"Sun halos are related to other phenomenon like sun pillars. If you see the sun setting and the ice falls, you see a pillar of light," Dr Enrico Olivier, astronomer at the South African Astronomical Observatory told News24.
"With a sun dog, you see three suns when its setting," he added.
Olivier said that they had 15 phone calls on Monday about the halo around the sun.
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