1. Aude Lemonsu, S. Bélair, J. Mailhot

2. Urban canopy models are physically-based models parameterizing radiative, energetic and turbulent exchanges between urban canopy and atmosphere Town Energy Balance, TEB (Masson, BLM, 2000)  Simplified 3D geometry of urban canopy (idealized canyon according to Oke, 1987)  Radiation trapping inside the street  Heat storage  Mean urban microclimate inside the street  Water and snow on roads and roofs  Anthropogenic forcing of heat and humidity

3. - Mexico city center (Masson et al., JAM, 2002) - Light-industrial site in Vancouver (Masson et al., JAM, 2002) - French old city core (Marseille) (Lemonsu et al., JAM, 2004) - French suburban catchment (Lemonsu et al., HP, 2006) Marseille Mexico Vancouver Rezé, Nantes TEB off-line evaluation

4. Q*QHQH QEQE ΔQSΔQS W m -2 Surface energy balance Average on 21 days of simulation Time (hr) Model Obs TEB off-line evaluation Marseille city center (ESCOMPTE-CLU, summer 2001)

5. Urban canopy models are coupled to atmospheric mesoscale models in order to simulate the impact of built-up covers on atmospheric boundary layer and local meteorology The coupling of TEB with GEM and MC2 models requires:  To implement a new type of surface in the physics package to include built-up covers  To provide new input databases  Urban land-use land-cover databases  Anthropogenic sources of heat and humidity Coupling with atmospheric models Sea ice Soil Vegetation Glaciers Water Urban

6. Coupling with atmospheric models Atmospheric model z atm Vegetated canopy Urban canopy Water body TEB

7. 6 4 2 0 m s -1 Meso-NH, included TEB, has been run for French cities  Urban heat island  Specific structure of the urban boundary layer  Urban breeze and urban plume Atmospheric modeling including TEB Paris Lemonsu and Masson, BLM, 2002

8. TEB is now included in the physics package of GEM and MC2 The system is currently evaluated for North-American cities  Oklahoma City (Joint Urban 2003) under warm and dry conditions - North-American city centers - Large residential irrigated districts  Montreal (MUSE) during wintertime - Evaluation of the snow scheme New Canadian urban modeling system Oklahoma City Montreal (MUSE 2005)