Iridescent Clouds Over Marietta, Georgia

February 04, 2010

20100204 – Thursday - Iridescent Clouds Over Marietta, Georgia

Photographer: David Riddle
Summary Author: David Riddle; Jim Foster

The photo above showing a splendid but short-lived display of iridescent clouds was taken over Marietta, Georgia on January 11, 2010. Iridescence is a diffraction phenomenon. In clouds comprised of microscopic water droplets, typically mid-level clouds, the small droplets act to deflect rather than simply refract sunlight. Because of the wave nature of light, the colors overlap and are more pastel in appearance than colors that result from refraction. When droplets are similar in size throughout the cloud, the colors are apt to be purer and brighter than is the case for droplets of assorted sizes.

Coordinates for Marietta, Georgia: 33.952244, -84.525244