3D evaluation of Urban Canopy Parameters (UCP) on Turin, Italy, with COSMO 6.0

The recent implementation of TERRA URB (TU) in COSMO represented an important step towards an improved and more realistic parameterization of urban processes in NWP models. In fact, the new external parameters introduced by TU and derived from the Local Climate Zones classification system, such as the anthropogenic heat flux, the impervious surface area fraction and several urban canopy parameters (UCP), yield to an accurate modelling of the complex interplay between the urban environment and the atmosphere. In previous works, e.g. at ICCARUS 2021, we showed that this new parameterization is able to capture the Urban Heat Island effect at the ground-level. The aim of the present study is to further explore its features on a three-dimensional level over the city of Turin (Italy), by analysing the vertical profiles simulated by the latest release of COSMO (6.0) at 1km resolution. We perform a sensitivity analysis on one week-case study, where the default values of the UCP are changed from lower to higher settings in order to understand their potential impact on the overlying atmosphere. The simulation results are compared with data observed by three radiometers, one located in the city centre and the others in the rural surroundings. Indeed, our results show the relevance of analysing the urban parameterization also from the poorly investigated 3D point of view, at least up to 1000m of elevation reached by the radiometers.