Lenticular Cloud Over Sardinia

November 15, 2013

SardiniaLenticularepod (4)

Photographer: Francesco De Comite
Summary Authors: Francesco De Comite; Jim Foster

The photo above showing a multi-layered lenticular cloud was observed near sunset from Cagliari, Sardinia, Italy. Lenticular clouds (Altocumulus lenticularis) are stationary wave clouds that typically form when air is forced to rise after encountering a mountain range or other elevated terrain. These lens shaped clouds appear at intervals closely related to the wavelength of the airstream (wave layer). Water vapor within the wave layer condenses at the highest point of the wave (crest) once the air is sufficiently cooled. At the bottom of the wave (trough), where the air is slightly drier, the cloud evaporates due to adiabatic heating. Note the faint anticrepuscular rays below the cloud -- the camera was facing east. Photo taken on September 17, 2013.

Photo details: Camera Maker: FUJIFILM; Camera Model: FinePix SL1000; Focal Length: 13.7mm; Aperture: f/4.8; Exposure Time: 0.0048 s (1/210); ISO equiv: 100; Software: GIMP 2.6.11.