
Katerina Russo saw this circumzenithal arc in Casore del Monte, Tuscany, Italy on August 9, 2016.
Circumzenithal arcs have been described as an “upside down rainbow” or “a grin in the sky.” But circumzenithal arcs are not really rainbows. Instead, they’re caused by ice crystals in the upper atmosphere.
Find out more and see photos here.
Thanks for sharing your photo with us Katerina!
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