Distrail, Hole Punch Cloud and Fallstreak Over Belgium

November 15, 2015


Photographer: Dirk Devlies
Summary Authors: Dirk Devlies; Jim Foster

The above photo showing a distrail (dissipation trail), hole punch cloud and fallstreak was observed from Bruges, Belgium. Distrails and hole punch clouds result when an aircraft (the path of a jet can be seen in the clouds at upper left center) passes through a thin layer of clouds, such as the altocumulus cloud deck shown above. Supercooled water droplets composing these clouds will freeze instantly when perturbed by the wings and tail of an aircraft. The resulting heat of fusion warms the air and evaporates the cloud deck, as long as the clouds aren't too thick. Also, note the faint sundog in the fallstreak at lower right center -- the Sun was off the picture to the right. Photo taken looking west about an hour before sunset on July 10, 2015.
Photo Details: Camera Model: NIKON D90; Focal Length: 150.0mm (35mm equivalent: 225mm); Aperture: ƒ/8.0; Exposure Time: 0.0010 s (1/1000); ISO equiv: 200.