crepuscular rays (photo by Stuart Gallaway)
In this photograph a number of wide bands of blue can be seen with several narrow bands
between them. (photo by K.B. Shone, UK)
One sometimes observes dark bluish streaks which radiate from the sun across the purple
light. These streaks are the shadows of clouds at or below the horizon; becoming visible at the
antisolar point (anticrepuscular rays)
Note
- The name "crepuscular
rays" is also used, though not universally, to denote shadowed
bands cast by clouds on a layer of haze at any time of the day.