lee waves

In meteorology, lee waves, are atmospheric standing waves. The most common form is mountain waves, which are atmospheric internal gravity waves, and were discovered in 1933 by German glider pilots above the Riesengebirge. They are periodic changes of Atmospheric pressure, temperature and orthometric height in a current of air caused by vertical displacement, for example orographic lift when the wind blows over a mountain or mountain range. They can also be caused by the surface wind blowing over an escarpment or plateau, or even by upper winds deflected over a thermal updraft or cloud street.
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