Gravity waves in the sky are usually invisible, but satellite images captured recently show a rare glimpse of the phenomenon off the coast of northwestern Australia.
The images show the air moving away from the land and ocean as a kind of rows of curved white lines. These thin white bands are clouds forming on the ridges of atmospheric gravity waves. Andrew Miskelly @andrewmiskelly A longer animation highlighting the atmospheric gravity waves. Waves cause the air to rise and sink, cooling and warming its water vapour and making upper water vapour temperature an effective means of visualisation. In some cases, cloud forms on the crests. //t.co/af6kfO2U9Q 2:54 AM - Oct 22, 2019 239 105
Gravity waves appear after atmospheric disturbances. In this case, they were triggered by storms in the area, which produced cold air, which is denser than warm air above the earth. The interaction between the cold and warm air stirred up the atmosphere, and the ripples formed were gravity's way of restoring that lost balance.
Unlike gravitational waves, which are theoretical ripples in space-time proposed by Einstein's theory of general relativity, gravitational waves are a physical phenomenon. For example, imagine ocean waves or the ripples that form in a lake after you throw a pebble into the water. Although we can't usually see gravity waves in the atmosphere, they do behavethe same way liquids do when they are disturbed, according to the National Oceanic and Atmospheric Administration (NOAA).
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Atmospheric gravity waves take shape from the push and pull between gravity and buoyancy; when the air is disturbed, gravity pulls the air down and the buoyancy of the air pushes it back. In some cases, when there is plenty of moisture in the air, water condensation creates white vapor contours along the crests of the oscillating air waves; the white lines becomedissipate when the air sinks into valleys.
When this happens, the rippling lines of the waves are visible to satellites, as was the case with Japan's Himawari-8 geostationary weather satellite, which captured the images.
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A large cloud of brown dust carried from the ocean along the Australian coast was also observed, making the waves even easier to detect, the Australian Broadcasting Corp. (ABC) reported.
SOURCE / Live Science