Lenticular Iridescent Clouds Over Brasilia, Brazil

May 01, 2018


Photographer: Leonardo Caldas
Summary Authors: Leonardo Caldas; Jim Foster

Featured above is a particularly colorful set of iridescent lenticular clouds as observed in the western sky over Brasília, Brazil, just before sunset on February 27, 2018. Mid-level lenticular clouds, composed of tiny water droplets, form in the crests of lee waves, where they may remain nearly stationary for hours. The pastel colors seen when a cloud becomes iridescent result from diffraction of sunlight by cloud droplets having similar sizes. In general, the purer the color, the more uniform the drop size. Because iridescence almost always occurs in the vicinity of the Sun, make sure to protect your eyes when looking at these clouds.

Photo Details: Camera: NIKON D5300; Software: Adobe Photoshop Lightroom Classic 7.0 (Windows); Exposure Time: 0.0006s (1/1600); Aperture: ƒ/5.6; ISO equivalent: 100; Focal Length (35mm): 300.