Author(s)

S.-E. Gryning & E. Batchvarova

Abstract

Applied modelling of the mixing height over heterogeneous terrain i <2 S.-E. Gryning & E. Batchvarova 1 2 ' Ris0 National Laboratory, Roskilde, Denmark 9 National Institute of Meteorology and Hydrology, Sofia, Bulgaria Abstract The use of simple operational commonly applied models for the determination of the mixing height over non-homogeneous terrain is considered. The study is restricted to unstable boundary layers. The use of a simple slab model to predict the mixing height over non- homogeneous terrain is discussed in relation to the scales of the terrain heterogeneity. The modifications of the slab model to account for the effect of abrupt step changes in the surface conditions, i. e. coastal areas, and the formation of the (internal) boundary layer is considered. The use of Numerical Weather Prediction model output for mixing height estimation by use of bulk Richardson numbers is discussed. Slab models were found to perform well

Keywords