Iridescent Clouds Over Jamestown, Colorado

June 06, 2017

Irides_unedited (4)

Photographer: Jill Bielawski
Summary Authors: Jill Bielawski; Jim Foster

Shown above are iridescent clouds as observed in an altostratus cloud deck over Jamestown, Colorado on April 10, 2017. The lovely opalescent colors are as they appeared to my eye -- unenhanced using computer software. Iridescent clouds are essentially a detached portion of a solar corona, most often forming within a few degrees of the solar disk. For this reason, always use extreme caution when looking at either coronas or iridescent clouds. Like the corona, iridescence (also referred to irisation) occurs when sunlight is scattered by the tiny water droplets that compose mid-level clouds. Note, chromatic bands such as this may be seen along certain cloud edges, perhaps because this is where droplet size varies the most in mid-level type clouds. 
Photo Details: Camera Maker: Apple; Camera Model: iPhone 6; Focal Length: 4.15mm (35mm equivalent: 58mm); Digital Zoom: 2.003x; Aperture: ƒ/2.2; Exposure Time: 0.0001 s (1/20000); ISO equiv: 40.