This spectacular, multi-hued formation of so-called lenticular clouds was observed over Rocky Mountain National Park, near Estes Park, Colo. Professional…Read More »
photographer Richard H. Hahn snapped the magnificent view soon after sunset at 5:02 p.m. MST (7:02 EST) on Jan. 5.
Lenticular clouds form when waves of moist, fast-moving air are pushed upward by winds and ascend over high mountains. At the mountain's higher altitude, the moist air's water droplets cool and expand, and the water vapor condenses. When the air moves over the mountain top and descends to uniformly humid air conditions, lenticular clouds form.
These clouds are characterized by their smooth, symmetrical oval or round shapes, and because of this, are often referred to as "flying saucer" or "UFO" clouds.
"The significance of this particular atmospheric event was the dramatic shape and color of the cloud. It really did look like the 'mother ship' UFO," Hahn told LiveScience.com. "It was ominous and breathtaking." Less «
Dark clouds gather over a campsite on the Tibetan Plateau. The photographer wrote of this photo, "Everybody was watching the monsoonal arcus cloud rolling…Read More »
over the camp. Suddenly, the weather changed. Rubbish was flying around and three men were hanging at the kitchen tent to keep it in place. This fascinating view presented itself shortly before the place turned into chaos." Less «
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Credit: Capt. Andreas M. van der Wurff
A roll cloud, associated with thunderstorm downdrafts and strange sea winds, tumbles across the sky off the coast of Brazil. Roll clouds are rare and harmless, though ominous-looking.
Swallows swoop below storm clouds, feeding on insects sucked skyward by updrafts.
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Credit: Markus Rex, Alfred Wegener Institute
These polar clouds, which are composed of frozen nitric acid and sulfuric acid, form when temperatures in the stratosphere fall below minus 108 F (minus…Read More »
78 C). This is currently the case in vast sections of the Arctic. Chemical processes on the surface of the cloud particles transform the initially harmless chemicals from chlorofluorocarbons (CFCs) into aggressive ozone-depleting substances. Less «