October 29, 2020 - Cloud Vortices and Dust off Canary Islands

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   Cloud Vortices and Dust off Canary Islands
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   Swirling patterns in the cloud cover behind the Canary Islands greeted
   NASA’s Aqua satellite as it passed overhead in late October 2020. The
   Moderate Resolution Imaging Spectroradiometer (MODIS) on board that
   satellite acquired a true-color image of the scene on October 26.

   The swirls are caused by wind rushing past the tall volcanic peaks on
   the Canary Islands. These spiral eddies are known as von Kármán
   vortices and are a pattern that can form nearly anywhere fluid flow is
   disturbed by an object. In this case, as winds from the northeast
   strike the towering mountains, the winds are diverted around these
   peaks, and the disturbance in the flow of wind propagates downstream in
   the form of vortices that alternate their direction of rotation. When
   clouds are present, the movement of the air will be shown in the
   clouds.

   On this particular day, the wind was strong enough to create some
   eddies, but only for a short distance. Dust from the Sahara Desert is
   entrained in the clouds that lie nearest the coast of Africa.

   Image Facts
   Satellite:  Aqua
   Date Acquired: 10/26/2020
   Resolutions:  1km (203.5 KB),  500m (652.7 KB),  250m (1.8 MB)
   Bands Used: 1,4,3
   Image Credit: MODIS Land Rapid Response Team, NASA GSFC



https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2020-10-29
 
