Double Rainbow Sunrise

Rainbows Over Lake Michigan by James Eye View Photography

Atmospheric Optics is the go-to for information about rainbows and other marvelous sights in sky. They explain the science behing double rainbows:

Light can be reflected more than once inside a raindrop. Rays escaping after two reflections make a secondary bow.

The secondary has a radius of 51º and lies some 9º outside the primary bow. It is broader, 1.8X the width of the primary, and its colours are reversed so that the reds of the two bows always face one another. The secondary has 43% of the total brightness of the primary but its surface brightness is lower than that because its light is spread over its greater angular extent. The primary and secondary are are concentric, sharing the antisolar point for a center.

James got some great shots of a double rainbow at sunrise over Lake Michigan in Empire yesterday morning. See more by clicking the pic. and view & purchase his work on his website.