Cumulonimbus Clouds (Cb)

The flight from Frankfurt to Heraklion took place between 3 p.m. and 7:30 p.m. The cruising altitudes ranged between 10 km and 11.3 km. Here the outside temperatures were around - 44 deg C. These images contain different large Cumulus clouds. Cb_calvus.jpg shows a Cumulonimbus calvus cloud during its development to a Cumulonimbus cloud. A distinct anvil does not exist yet, but apparently the icing has already started at the front part of the cloud (near the wings).

Cb_extent.jpg displays a Cumulonimbus cloud extending horizontally at the top of an inversion. This inversion is probably not the tropopause, since the aircraft travelled at an altitude of 11.3 km. Hence the altitude of the tropopause is found to be rather at 13 km in the Mediterranean region in this season.

In the background of Cb_incus.jpg a fully developed Cumulonimbus cloud with an anvil (incus) can be recognized.

Cu_congestus.jpg contains several Cumulus clouds, including a major Cumulus congestus at the left side. The veil that seems to be growing from the wing at the right border of the picture is the extension of a cirrus shield around a Cumulonimbus incus cloud. Accordingly strong turbulences were noticed inside the aircraft.

S. Borrmann; flight from Frankfurt to Crete, 30 July 2001 joining the MINOS field campaign