Clouds Lit From Below

February 09, 2017

DaveL_PacificSunset

Sunlit_diagram_Lit%20from%20below%20diagram

Photographer: Dave Lynch
Summary Author: Dave Lynch

Most of the time clouds are lit from above. But sometimes sunlight can shine on them from below. The photo at top shows such a case. Looking southwest over the Pacific Ocean (not seen here because it's blocked from view by the mountain range) off southern California, a distinctly orange glow can be seen in the distance and on the underside of the clouds. These mid-level clouds are lit from below because sunlight is being reflected from the ocean. Waves on the ocean reflect the light over a broad range of angles so much of the underside of the clouds takes on an orange hue.

When the clouds are illuminated from above (very top of the picture) their colors are gray and white with little color. But because sunlight reflecting off the ocean passes through so much more atmosphere, absorption by atmospheric water vapor and aerosols renders it much redder. See the Earth Science Picture of the Day for December 6, 2016.

Photo Details: Camera Maker: NIKON; Camera Model: COOLPIX AW100; Focal Length: 12.8mm (35mm equivalent: 71mm); Aperture: ƒ/4.3; Exposure Time: 0.0010 s (1/1000); ISO equiv: 125; Software: COOLPIX AW100V1.0.