In meteorology and geophysics (analogous to the term tropopause ), an interface in the lower atmosphere is referred to as a peplopause (from ancient Greek λπλος peplos , German 'coat, airy garb' and παῦσις paũsis , German 'end' ) , 5 to 3 km above sea level. It is also known as the cladding layer .
It forms the transition between the ground-based base coat or planetary boundary layer - in which the air movement heavily from the bottom friction is affected - and the overlying part of the troposphere ( free atmosphere ). It is particularly pronounced in inversion weather conditions with cold, clear nights, where the peplopause often coincides with the upper limit of the high fog . Below the air contains an above-average amount of water vapor and aerosols due to the lack of mixing , so that a noticeable layer of vapor forms.
As a mountaineer you can often see the break in the summer months, when the valleys are still in the early morning fog , but the higher mountain slopes are already in the sunshine. The updrafts caused by radiation then swirl through the air at these altitudes and lead to a local shift in the haze limit. Even pilots know these " dirty " appearing interface, particularly on hazy days over the plains lies. It is flown through a few minutes after take-off and in these moments stands out clearly from the sky blue due to its brown-gray color . The distance vision improved from this altitude averaging 1,800 meters usually significantly.
In the mountains , the peplop occasionally also represents a reversal of the local wind systems , for example when terrain levels are accompanied by different albedo of the rock or changing vegetation . By convection can below local slope, up or valley winds develop, the above are compensated by differently directed winds. Experienced glider pilots use such weather conditions to achieve particularly long flight distances (see for example triangular flight at world championships).
- Karl Schneider-Carius: Lo strato base dell'atmosfera come determinante il clima delle Alpi . In: Geofisica pura e applicata . tape 17 , no. 3 , 1950, ISSN 1420-9136 , pp. 94-103 , doi : 10.1007 / BF02018346 .
- Ernst Heyer: Weather and Climate: A General Climatology . Vieweg + Teubner Verlag, Stuttgart / Leipzig 1993, ISBN 3-322-83746-7 , p. 15-16, 53-56 ( books.google.de ).
- Heinrich Faust: The structure of the earth's atmosphere: a summary presentation including the new rocket and satellite measurement results . Springer-Verlag, Wiesbaden 2013, ISBN 978-3-322-98769-3 , p. 14, 77, 91 ( books.google.de ).