Science & Technology

Mysterious Hovering Clouds Spotted Over the Transantarctic Mountains

December 29, 2020

Easy, stationary clouds are often reported by the public as sightings of “unidentified flying objects.” However these clouds are usually not as mysterious as they may first appear.

On December 29, 2020, the Operational Land Imager (OLI) on Landsat 8 acquired these photos of soft-edged clouds hovering over the Eisenhower Vary of Antarctica’s Transantarctic Mountains. The vary is bounded to the north by Priestley Glacier and to the south by Reeves Glacier, each of which feed into the Nansen Ice Shelf on Terra Nova Bay.

The clouds have the hallmarks of lenticular clouds that may kind alongside the crests of mountain waves. Mountain waves kind when fast-paced wind is disturbed by a topographic barrier—on this case, the Eisenhower Vary. Air is pressured to movement up and over the mountains, inflicting waves of rising and falling air downwind of the vary. The rising air cools and water vapor condenses into clouds. Conversely, falling air results in evaporation.

December 29, 2020. (Click on picture for wider, high-resolution view.)

Including to their mystique, this cloud sort seems to remain put—generally for hours—defying the sturdy horizontal winds. In actuality, the clouds are continuously constructing round the crest of the wave after which dissipating simply past.

In the United States, lenticular clouds are notably frequent round the Rocky Mountains. They’ve been identified to happen over Antarctic mountains, too, however there are usually not many witnesses apart from satellites. The white-on-white shade of clouds over ice make the Antarctic variations more durable to discern, even in satellite tv for pc photos. This natural-color picture has been enhanced with infrared gentle to separate the white clouds from the white snow and ice under. The clouds additionally threw rounded shadows on the panorama.

Nonetheless, a couple of folks have witnessed lenticular clouds in Antarctica firsthand. Scientists working with NASA’s Operation Icebridge shot images of the phenomenon in 2013 and in 2015.

NASA Earth Observatory photos by Joshua Stevens, utilizing Landsat knowledge from the U.S. Geological Survey. Story by Kathryn Hansen with picture interpretation by Bastiaan Van Diedenhoven (NASA GISS/Columbia) and Jan Lenaerts (CU Boulder).
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