Research School for Socio-Economic and
Natural Sciences of the Environment
Research School for Socio-Economic and
Natural Sciences of the Environment
Agenda

Joël Schröter

Date: 05 June 2018
Time: 16:00 - 17:30
Location: Aula, building 362, Gen. Foulkesweg 1, Wageningen

Dissertation title: 

Sheared convective boundary layers: turbulence kinetic energy and entrainment dynamics

Group: Wageningen University, Meteorology and Air Quality
Promotor: Prof.dr. A.A.M. Holtslag
Copromotor: Dr.ir. A.F. Moene

Extra information:

Abstract:

In my thesis I investigated the entrainment and growth dynamics of atmospheric boundary layers that are driven by both shear and a positive buoyancy surface flux. Using a series of large eddy simulations, I showed that over the whole stability range from purely convective to purely neutral conditions, entrainment scales with a linear combination of integral buoyance production and shear production of turbulence kinetic energy. Previously, such ideal behaviour had been assumed but never actually demonstrated, due to inappropriate assumptions about the flow structure. However, in certain conditions I also observed systematic deviations from the ideal behaviour. These are caused by local instationarity and the previously ignored formation of gravity waves at the upper boundary-layer interface. I show that these interfacial effects can be well represented using local scales. As final result I obtain a boundary layer model that is both very simple and much more precise than previous ones.