|Harald Sodemann (04/2002-09/2002)|
Evaluation of a Parameterisation for Turbulent Fluxes of Momentum and Heat in Stable Stratified Surface Layers
|Support: Thomas Foken|
|The stratification of the atmospheric boundary
layer strongly influences fluxes of mass and energy between the earth surface
and the atmosphere. Modelling these fluxes, e.g. in General Circulation
Models, is performed using parametrisations based on a range of simplifying
assumptions. For neutral and unstable stratification, these parametrisations
perform reasonably well. Under stable stratification however, the current
parametrisations lack theoretical consistency and contradict evidence from
new experimental findings (Zilitinkevich et al. 2001).
My Diploma Thesis aims to identify the influences of different turbulence regimes and other parameters on mass and energy fluxes in the stably stratified boundary layer, using data from the 1994 FINTUREX experiment in Antarctica. Quantifying the different influencing parameters is expected to lead towards deriving a new parametrisation scheme for turbulent mass and energy exchange under stable conditions. The results yield the potential for improving a range of modelling applications, such as footprint models or flux modelling.