Circumhorizontal arcs, especially when only fragments can be seen, are sometimes confused with cloud iridescence. This phenomenon also causes clouds to appear multi-coloured, but it originates from diffraction (typically by liquid water droplets or ice crystals) rather than refraction. The two phenomena can be distinguished by several features.
Circumhorizontal arcs, especially when only parts of them are visible, are sometimes mistaken for cloud iridescence. This phenomenon also causes clouds to appear multi-colored, but it is caused by diffraction (typically from liquid water droplets or ice crystals) rather than refraction. The two phenomena can be distinguished by several features.