The sub-grid model, sub-grid town energy budget (STEB), is developed in order to reproduce the surface energy budget over large urban areas. The STEB evaluates the energy budget of each building belonging to a built area by employing an accurate description of the canyon geometry. The STEB is coupled with the limited area model RAMS to simulate the urban heat island over the city of Rome, Italy. The model is initialised with a suitable urban digital elevation model, accounting for nearly 360,000 buildings. The results show that the coupled system RAMS-STEB reproduces adequately the behaviour of the main meteorological quantities.
Keywords: building, street canyon, urban heat island, town energy budget, TEB, surface energy balance, sky view factor, SVF, meso-scale models, urban canopy, boundary layer, climate