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Subsun

Subsun subsun  or  sub-sun  is a glowing spot that can be seen within  clouds  or haze when observed from above. The subsun appears directly below the  sun , and is caused by its light reflecting off of numerous tiny  ice crystals  suspended in the atmosphere. As such the effect belongs to the family of  halos . The region of ice crystals acts as a large  mirror , creating a  virtual image  of the sun which appears below the  horizon , analogous to the sun's reflection in a body of water.  The ice crystals responsible for a subsun are typically in the shape of flat hexagonal plates. As they fall through the air, their aerodynamic properties cause them to orient themselves horizontally, i.e., with their hexagonal surfaces parallel to the  Earth's  surface. When they are disturbed by turbulence, however, the plates start to "wobble", causing their surfaces to deviate some degrees from the ideal horizontal orientation, and causing the reflection (i.e., the subsun