Development and integration of a subgrid urban surface scheme in a limited area model

The subgrid model STEB (Subgrid Town Energy Budget) 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 initialized 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.