Iridescent Clouds Over Santos, Brazil

February 13, 2019

Iridescent Clouds (1)

Photographer: Meire Ruiz
Summary Authors: Meire Ruiz; Jim Foster

These eye-catching iridescent clouds or irisation were observed over SantosSão Paulo, Brazil during the late afternoon of January 8, 2019. Though iridescence more typically occurs in mid-altitude clouds (altocumulus, for example), colorfully-fringed clouds can also appear in stormy skies (pileus clouds), particularly atop columns of rapidly rising air. The pastel colors result from the process of diffraction; sunlight is diffracted about the outer edges of cloud droplets causing overlapping color orders. Always take care to protect your eyes when looking anywhere near the Sun.

Photo Details: Camera: Canon PowerShot SX60 HS; Software: Picasa; Exposure Time: 0.0005s (1/2000); Aperture: ƒ/8.0; ISO equivalent: 100; Focal Length: 27.1mm.