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| Sun dogs |
After witnessing several awesome displays of the northern lights this year, then posting about the how and why of that phenomena, I thought I'd write about another 'wonder in the sky' called parhelia, plus a bit about some related sky effects. Parhelia is an atmospheric spectacle which occurs in cold weather and is caused by ice crystals in the air. Typically referred to as "sun dogs' and appearing as a false sun, or suns, manifesting on either side of the actual sun, I've seen this quite often in Alberta winters and it's always fascinating.
A cousin of the sun dog is the solar halo, also referred to as a nimbus, icebow or gloriole. This is a ring of refracted light which forms a circle around the sun or moon, and can even occur around artificial lights when ice crystals, referred to as "diamond dust", are floating in the air nearby. The solar or lunar halo is created by light reflecting and refracting through the ice crystals in cirrostratus clouds in the upper troposphere, at 5 km - 10 km altitude.
Another oddity is the circumzenithal arc, which is a rainbow like arc positioned above the solar halo as shown in one of the photos below.
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| The science behind parhelia |
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| Sun dogs appear in cold temperatures |
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| Circumzenithal Arc |
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| A full sun halo plus sun dogs |
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| Ethereal, to say the least |
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| Rare double halo |
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| Sun dogs, partial halo and circumzenithal arcs |
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