From the Weather Center
by John Simon
August 2021
Rainbows
Rainbows are caused by the reflection, refraction, and dispersion of light in water droplets, resulting in a spectrum of light appearing in the sky.
The resulting spectrum takes the form of a multi-colored circular arc.
Rainbows caused by sunlight always appear in the section of the sky directly opposite the sun. Rainbows can be full circles, however, the observer normally sees only an arc formed by the illuminated droplets above the ground, and centered on a line from the sun to the observer’s eye.
Rainbows can be double rainbows, twinned rainbows, full-circle rainbows, or so on.
Rainbows can sometimes form in the moonlight at night, and there occasionally can be fogbows or sleetbows, as well.
Also, we don’t know why, but there are so many songs about rainbows and what’s on the other side.