Contrails

According to the radio weather forecast the 24 April 2004 was expected to be a "sunny spring day with brilliant blue sky". However, contrails cannot be "predicted". Hence the sky was covered with contrails more and more. They became broader until they finally resulted in a Cirrostratus layer. This layer lasted until the evening of the next day, whereby from Sky15.jpg it cannot be decided anymore, whether the clouds derived from the contrails or not. Mostly only observers can determine this watching the development over a longer period of time. The satellite images Satellite1.jpg and Satellite2.jpg clearly show that contrails covering the sky can be a meso-scale to regional phenomenon.

Since the aircrafts are only allowed to fly on vertically shifted paths due to safety reasons, the increasing covering of the sky with long-living contrails means that the humidity of a vertically larger layer in the upper troposphere is above ice saturation.

A sky which is even more covered by contrails or rather clouds which derived from them is presented in chapter Contrails Shadows (see Shadow6.jpg to Shadow10.jpg).

Sky1.jpg to Sky14.jpg (except Sky11.jpg Sky12.jpg): S. Borrmann, Ingelheim, Germany, 24 April 2004, 9:01 a.m. to 9:51 a.m.

Sky11+12.jpg: S. Borrmann, Ingelheim, Germany, 24 April 2004, 3:44 p.m. to 4:15 p.m.

Sky15.jpg: S. Borrmann, Ingelheim, Germany, 25 April 2004, 4:00:14 p.m.

Sky16.jpg: S. Borrmann, Ingelheim, Germany, 29 May 2004, 2:59 p.m.

Sky17.jpg and Contrails_Sky8.jpg: S. Borrmann, Ingelheim, Germany, 30 May 2004, 8:54 a.m.

Satellite1.jpg: Picture from the South of Germany, Austria and Switzerland made by the NOAA-12 satellite

Satellite2.jpg: Picture from Germany, Denmark, BeNeLux and the North East of France made by NOAA-12 AVHRR Satellite, 4 May 1995, 9:58 a.m.

Camera Parameters

Olympus E-1 SLR using a 14-54 mm objective. Exposure and ASA selectivity choice (100 ASA) was performed by the program automation of the camera. The images were taken in the sRGB colour range with a resolution of 2560 x 1920 pixel x 24 colours. Several images were made using a polarisation filter. More details see below.