1. Mick West

    How Rare (or Common) are Haloes, Sun Dogs, etc? A Review of the Literature

    The above image is one of the earliest representations of a solar halo and two sun dogs (also called parhelia, or "mock suns"). It's dated 1520 and is from the 1552 The Book of Miracles, the German 16th-century manuscript of supernatural phenomena, and looks like it was painted from memory, or...
  2. I

    Dark arc associated with cirrus ice cloud

    The halo (photographed in Bangkok) is probably a circumscribed halo (at 22 degrees) that is due to a predominance of longer hexagonal crystals that are falling horizontally. The feature that I do not understand is the dark concentric circular arc at four-five o'clock at about 31 degrees. It...