Stratus Clouds (St)
St Formation
St nebulosus
St fractus
St fractus pannus
St opacus


Stratus opacus Clouds

Cover.jpg: Shortly before passing the Swedish Baltic Sea coast an optically thick and massive stratus cover occurred. Since the layer is nearly impermeable for light it is named "opacus". The waves at the cloud top derive most probably from the mountains below.

Opacus 0-17.jpg: This series shows a seven-minute lasting part of the descent to Berlin. At first the aircraft travelled above a stratus cover for quite a while and then dived into it before landing. One can recognize the optical thickness from the top and the relative darkness while flying through the cloud cover. The last images display the cloud cover from below. Thereby it becomes clear that the sun radiation is effectively shielded by the clouds.

Opacus18-26.jpg: The departure of the aircraft passing two thick stratus covers on top of each other is shown in this series. In the case of Opacus23.jpg the aircraft has just passed the bottom layer and approaches the upper one. One can recognize the bottom of the upper stratus layer. From the top view (Opacus25+26.jpg) the upper one has a significantly less-structured surface than the one in the previous series (e.g. Opacus2.jpg).

S. Borrmann, flight from Stockholm to Frankfurt, 22 June 2002 from 1:00 to 3:00 p.m.

S. Borrmann, flight from Frankfurt to Berlin (Tegel), 10 October 2004, 10:58 a.m. to 11:07 a.m.

S. Borrmann, flight from Frankfurt to Berlin (Tegel), 9 July 2004, 7:11 a.m. to 7:20 a.m.