The scientific aim of the proposed work is to study dynamical processes within the atmospheric boundary layer (ABL) that affect the vertical exchange of heat, momentum, water vapour and pollutants between the underlying surface and the free atmosphere. The studies will combine the analysis and interpretation of sodar measurements with the use of simple numerical models.
In detail, the following issues will be investigated:
- determination of the ABL-height and of the depth and internal structure of the entrainment zone (EZ) at the top of a convective boundary layer / realization of different algorithms for the estimation of the EZ-thickness from sodar data and comparison with results from radiosonde/tethersonde observations,
- identification of data processing procedures to derive the relevant input parameters for the coupled mixed- layer/entrainment-zone model of Batchvarova and Gryning (1994) from sodar data,
- validation of the model proposed by Gryning and Batchvarova (1994) using sodar data
- investigation of wind shear and wave processes at the convective boundary layer top and their contribution to the entrainment process. Taking into account the significance of entrainment zone processes to the vertical exchange of energy and matter between the polluted ABL and the free troposphere, the elaboration of operational methods to estimate basic mixed layer and entrainment zone parameters is considered to be of high practical relevance.