Where on Earth: Foggy Peru

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What is the white material shown in this satellite image?

Produced by the Space Telescope Science Institute’s Office of Public Outreach in collaboration with the NASA Earth Observatory (https://earthobservatory.nasa.gov/).
Story adapted from Image of the Day post by Kathryn Hansen: https://earthobservatory.nasa.gov/images/89312/foggy-peruvian-valleys

  • mage of Fog-filled Peruvian valleys by the Operational Land Imager (OLI) on Landsat 8
  • Image of Loma Community, Chile by Gisela Stotz
  • Written by Katherine Porter
  • Designed by Dani Player
  • Music from Yesh Music (ASCAP)

Various square, diverse, high altitude images of Earth landscapes. Segment title-- Where on Earth? High altitude landscape of brown land veined with white. What is the white material shown in this satellite image? A, glacial ice in Iceland; B, low level clouds in Peru; C, salt crystals in Australia; D, frozen lake water in Russia. Correct answer highlighted. B, low level clouds in Peru.

Labels appear on image. Image source is operational land image or land sat eight. Central land between two veins of white is labeled, "high desert." Left vein of white is labeled, "Akari River Valley." Right vein of white is labeled, "Yauka River Valley." Thick clouds frequently fill the deep river valleys along Peru's southern coastal desert. These clouds are marine stratocumulus a type of low level clouds so close to Earth's surface that it is essentially fog.

The clouds appear bright white because they reflect most of the sunlight that strikes them. Hidden beneath the clouds in the southwestern portion of the image lies the Pacific Ocean-- the source of the moisture that makes up the clouds. Label reading, "Pacific Ocean" appears. Marine stratocumulus clouds generally develop off the coast of Chile and Peru during the winter and early spring.

They are then pushed inland, up the low river valleys, by prevailing winds. Inset image appears. Desert vegetation with fog. Caption-- Loma community, Chile. (Gisela Stotz.) Clouds like these support Lomas, or fog oases-- communities of vegetation that are watered by the fog. Inset image disappears. Main image replaced by higher altitude, image of similar landscape without clouds. Zoom out to reveal the Peruvian coastline of South America. Continue zoom out to show animation of Earth from space. Caption-- "music courtesy of Yesh Music ASCAP.