Asperatus Clouds Over the Canary Islands

January 08, 2018

Asperitas sobre pici viejo 26 nov 17 -1-2 (1)

Photographer: Roberto Porto
Summary Authors: Roberto Porto; Jim Foster

Shown above is fantastical sky that looks like it could have been painted by an impressionist artist. I captured this photo in Teide National Park, on the Canary Island of Tenerife (Spain), during the afternoon of November 26, 2017. Referred to as asperatus clouds, it now seems that they form in similar atmospheric conditions that result in mammatus type clouds -- air cooled by the sublimation of ice crystals punching through an existing cloud base. However, with asperatus, strong wind shear at the cloud level causes the clouds to shape into wave-like structures called undulatus. They're not often seen, but when they are, they're always captivating.