Red Rainbow at Sunrise

September 10, 2011

Photographer: Ed Groth
Summary Authors: Ed Groth; Jim Foster

The photo above showing a reddened rainbow was taken from Cortland, New York, about one minute before sunrise and with rain moving in from the west. This bow is much redder than a rainbow seen after sunup or before sundown; it's a dramatic illustration of the preferential scattering of blue light by our atmosphere. The violet, blue, green and yellow colors have been attenuated by the greater path length sunlight takes when the Sun is close to the horizon. A secondary rainbow is barely visible to the upper right. Photo taken on July 28, 2011. Compare this photo with yesterday's Earth Science Picture of the Day.

Photo Details: Camera Maker: NIKON; Camera Model: COOLPIX L24; Focal Length: 10.8mm (35mm equivalent: 61mm); Aperture: f/4.0; Exposure Time: 0.017 s (1/60); ISO equiv: 250.