Iridescent Lenticular Display Over Lethbridge, Alberta

June 17, 2014

APOD

Photographer: Patricia O. Polo
Summary Authors: Patricia O. Polo; Jim Foster

During a bitter cold, late February photo shoot on the outskirts of Lethbridge, Alberta, I was able to capture a portion of a spectacular, 30-minute display of iridescent lenticular clouds. These mid-level wave clouds are composed of fine water droplets. The metallic colors are attributed to deflection (and wave interference) of sunlight by the similarly-sized droplets. Lenticular clouds are often found on the lee side of mountain ranges, as was the case here. A mountain range's considerable relief can trigger the formation of atmospheric waves -- typically between about 2-4 mi (3-6 km) above the Earth's surface. Note, the surface air temperature was between -18 F and -22 F (-28 C to – 30 C). Photo taken on February 28, 2014.