Tag Archives: circumhorizon arc

(…all the way)

Not quite.

Actually, an ice halo photographed over Dublin, Ohio, in 2009. To wit:

The reason here is that ice crystals in distant cirrus clouds are acting like little floating prisms. Sometimes known as a fire rainbow for its flame-like appearance, a circumhorizon arc lies parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds are present. Furthermore, the numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are quite unusual to see.

(Image:Todd Sladoje)

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