Circumhorizon Arc over Viterbo, Italy

July 26, 2021



Photographer: Marco Meniero 

Summary Authors: Marco Meniero; Jim Foster

Arguably the most colorful of all ice haloscircumhorizon arcs are only seen when the Sun is high in the sky, around the noon-time hour during the summer season in the mid latitudes. When sunlight enters one of the vertical side faces of a six-sided ice crystal and then exits through the horizontally oriented basal face, these colorful arcs may appear below the position of the Sun. This one was detected over Viterbo Airport in Rome, Italy, on June 4, 2021. A closeup view is shown below. Always protect your eyes when looking anywhere near the Sun.

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