CFD modelling:The most useful tool for developing mesoscale urban canopy parameterizations

1 Introduction The fact that most of the world’s population lives in cities(UN-Habitat 2016)has increased interest in urban meteorology.Mesoscale models,such as the Weather Research and Forecasting(WRF)model(www.mmm.ucar.edu/weather-research-and-forecasting-model),are used to reproduce the meteorology and climatology over cities and around them,where the complex interactions between the atmosphere and urban surfaces(buildings,vegetation,urban obstacles,etc.)induce strong heterogeneity in the flow properties within the urban canopy layer(UCL)(Di Sabatino et al.2013;Lateb et al.2016;Tominaga and Stathopoulos 2016).