Investigation of entrainment processes at the top of the atmospheric boundary layer using innovative experimental and numerical techniques
Responsible: Siegfried Raasch, Jens Bange, Sabrina Martin, Florian Herbort
Project type: NTH research project
Duration: 2010 -

The atmospheric boundary layer (ABL) represents the part of the atmosphere, which is directly affected by the processes taking place at the Earth's surface. The depth of the ABL depends on the meteorological situation and reaches 500 to 2000 meters in mid latitudes. Thereover a thermal inversion usually exists of 10 to 100 meters thickness. This inversion hinders vertical transport from the ABL into the free atmosphere across. The interchange of energy and matter is provided by entrainment which is the input of air from the inversion into the ABL primarily caused by convective processes leading to a deepening of the ABL.
Due to the large grid space of numerical weather and climate models, entrainment processes have to be parameterized. An improvement of the knowledge of the entrainment processes benefits numerical weather prediction and climate models, that are currently often equipped with poor parameterizations of the above mentioned processes. However the entrainment region is directly connected to the drive of the large-scale weather development.
On the one hand experimental methods using meteorological instruments on mini aircrafts and on the other hand numerical simulations using PALM are expected to enlarge the knowledge of entrainment processes.

Last modified 13 years ago Last modified on Apr 27, 2011 3:22:15 PM