A ONE-DIMENSIONAL WIND MODEL FOR DIFFUSION CALCULATIONS

A simple one dimensional wind model, designed for diffusion calculations in flat environments with obstructions, is proposed. It covers the surface layer and up to a maximum height of 500 m with three levels. The lowest level is the internal boundary layer, in which the influence of the immediate environment is manifest. The second is the surface layer in which the wind profile is characterized by the fetch conditions further upstream. The third is the spiral layer, where the wind turns with height. The actual depth of the surface layer is estimated by the model. In both the surface layer and the internal boundary layer, Monin-Obukhov theory is applied. The spiral layer is represented by a classical Ekman-Taylor solution matched at the top of the surface layer. This conceptual model is then tested with data from a meteorological mast at Garching (near Munich, Germany).