Approach based on improved urban roughness and fluxes

3 Approach based on improved urban roughness and fluxes 

This module includes algorithms for calculating the following urban parameters for the NWP model and steps for each model grid having urban features  

It is reasonable to use this method for relatively cheap simulations and for NWP models with a low vertical resolution (first computational vertical level higher than 20 m), when other more complex models of the urban sub-layer (e.g., BEP and SM2-U) would not much affect results or would be too expensive for operational forecasting applications. This module, with some simplifications, was implemented and tested 

It is noteworthy that the suggested improvements based on the canopy profile model and displacement height do not required to substantially modify the NWP model itself, because the first computational model level is usually above the canopy, so that the canopy parameterisation can be used only for diagnostic calculation of the wind for higher resolution UAQ modelling outside the NWP model or for diagnosis of 10 m wind in NWP. 

In general, the SEB in urban areas can be written in the following way (Piringer and Joffre, 2005)  

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