Contrails

The contrails of Shadow1.jpg and Shadow2.jpg cast shadows into the "blanc air". The shadows are reproduced on cloud particles in the air which occur in such low number densities that the observer does not notice them as cloud anymore.

At Shadow3.jpg and Shadow4.jpg an aircraft contrail produces shadows during sunset. They fall on a Cirrus cloud layer which is located above the contrail.

Shadow5.jpg shows two contrails on which clouds of the neighbourhood cast their shadows at.

Shadow6-10.jpg display contrails above a Cirrostratus layer. At high sun level they cast their shadows onto these clouds.

Shadow11.jpg and Shadow12.jpg: The aircraft was found to be between a Cirrus cloud layer with embedded, already aged contrails and a discontinuous Altostratus cloud layer. At the time of exposure a larger gap appeared in the Altostratus layer. The contrails cast a weak shadow onto the haze below the wing.

Shadow13-20.jpg: The photographer took the images from an airplane which was located between the shading contrails and the "projection surface" consisting of a closed stratus cover here.

Shadow21-24.jpg: After sunset the contrails are already shadowed by the earth, whereas the clouds at larger altitudes (Cirrus clouds and other contrails) are still illuminated by the sun.

Contrails of aircrafts moving from east to west are worthwhile to observe at sunrise. Then extremely long contrails that are still located in the dark will be illuminated more and more from east to west when the sun rises up. Under these conditions the observer sees how the sunlight migrates along the contrail, until it has outrun the aircraft. It happens that way, since the projection of the rising sun on the stripes moves faster to the west than the subsonic aircraft. It is just a spectacular perspective. (The situation would be different with a supersonic aircraft).

Shadow1.jpg: S. Borrmann, Pulpit Rock, Carinthia, Austria, 30 December 2001, 2 p.m.

Shadow2.jpg: S. Borrmann, Ingelheim, Germany, June 2002

Shadow3+4.jpg: S. Borrmann, Ingelheim, Germany, June 2002

Shadow5.jpg: S. Borrmann, Pulpit Rock, Carinthia, Austria, January 2003

Shadow6-10.jpg: S. Borrmann, MPI for Chemistry, Mainz, Germany, 30 June 2004, 3:22 p.m.

Shadow11+12.jpg: S. Borrmann, flight LH 974 from Frankfurt to Munich, 9 September 2005, 4:27 p.m.

Shadow13-20.jpg: S. Borrmann, flight LH 4172 from Frankfurt to Lyon, 7 January 2006, 1:14 p.m. to 1:56 p.m.

Shadow21-24.jpg: S. Borrmann, Alpe d'Huez, French Alps, 8 January 2006, 5:00 p.m.