Sensitivity of WRF/urban simulations to urban morphology parameters: A case study in the city of Bolzano

The recent progress in numerical weather prediction modelling, and in particular the possibility to reach increasingly finer spatial resolutions, allowed researchers to reproduce building-atmosphere interactions in a more accurate and realistic way, especially in urban areas. The present work aims at evaluating the impact of highresolution gridded datasets of urban morphology parameters on the results of numerical simulations of atmospheric processes performed with the WRF/Urban suite in the city of Bolzano (Italy), and to analyze how they affect near-ground temperature fields. A sensitivity test was carried out, combining the WRF model with the Building Effect Parameterization (BEP) scheme to simulate two typical clear-sky summer days, respectively with and without the input gridded data of urban morphology. The structure and the morphology of the city of Bolzano were carefully reproduced through several fine-scale morphometric parameters from surface and terrain models (0.5 m resolution). The results highlight that urban morphological parameters display a high spatial variability, moderately affecting the distribution of the temperature field near the ground. High-resolution meteorological fields inside urban areas can be valuable information for building energy simulations. Accordingly, a scheme of model chain coupling WRF and TRNSYS codes is proposed, in order to enhance the future assessment of urbanization effects and in the same way to provide more realistic and accurate building energy simulations.