December 22, 2020 - Fog in California

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   Fog in California
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   Wintertime in California’s Central Valley means snow in the high Sierra
   Nevada and a blanket of tule fog hanging low over the Valley floor. The
   Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA’s
   Terra satellite acquired a true-color image of Central Valley fog on
   December 20, 2020. This relatively narrow bank stretches about 325
   miles (523 km) from north to south.

   Tule fog is an exceptionally dense fog that forms in the Central Valley
   each winter after the ground has become damp from a recent rain. During
   the day, the warmth of the Sun causes the moisture to evaporate into
   the air. After sunset, air temperature slowly drops. Because cool air
   can hold less moisture than warm air the many tiny moisture droplets
   suspended in the air during the day combine into large droplets,
   creating “low cloud”, or fog. Tule fog tends to form—often rapidly—
   after sunset, become thickest just before dawn, then slowly thins as
   the air warms in the morning.

   Image Facts
   Satellite:  Terra
   Date Acquired: 12/20/2020
   Resolutions:  1km (97.7 KB),  500m (338.8 KB),  250m (1010.8
   KB)
   Bands Used: 1,4,3
   Image Credit: MODIS Land Rapid Response Team, NASA GSFC



https://modis.gsfc.nasa.gov/gallery/individual.php?db_date=2020-12-22
 
