Update: Sun dog spotted over Deeside was a ‘circumzenithal arc’

This article is old - Published: Tuesday, Aug 16th, 2016

Update: Weather boffs at the BBC have said yesterday’s sighting of what we believed to be a ‘sun dog’ was, in-fact a ‘circumzenithal arc’

A few of our Weather Watchers in North East Wales spotted this lovely circumzenithal arc yesterday evening. pic.twitter.com/WPgwQMLDm6

— BBC Weather Watchers (@BBCWthrWatchers) August 17, 2016

According to Wikipedia:

The circumzenithal arc, also called the circumzenith arc, (CZA), upside-down rainbow, and the Bravais’ arc, is an optical phenomenon similar in appearance to a rainbow, but belonging to the family of halos arising from refraction of sunlight through ice crystals, generally in cirrus or cirrostratus clouds, rather than from raindrops.

The arc is located at a considerable distance (approximately 46°) above the sun and at most forms a quarter of a circle centered on the zenith.

It has been called “a smile in the sky”, its first impression being that of an upside-down rainbow. The CZA is one of the brightest and most colorful members of the halo family.

Its colors, ranging from violet on top to red at the bottom, are purer than those of a rainbow because there is much less overlap in their formation.

Jacqueline Marshall tweeted the picture of the atmospheric phenomenon.