eTheses Repository - University of Birmingham

initialisation phase lasting 2-8 hours the orography grows slowly (diastrophism) until the
real heights are established.
3.2 BEP
The urban canopy model BEP (Building Energy Parameterisation) developed by Martilli et
al. (2002) to parameterise the dynamic and thermodynamic effects of the urban canopy has
been implemented into the mesoscale model METRAS. BEP is described and validated in
the following papers: Martilli et al. (2002), Martilli (2002) and Roulet et al. (2005). This
model has been applied to study air quality for the city of Athens (Martilli 2003; Martilli et
al. 2003) and has been subsequently implemented in other mesoscale models in order to
improve the representation of the urban surface, for example the MeteoSwiss operational
numerical weather prediction model aLMo (Clappier et al. 2005; Muller 2007), the high-
resolution version of the operational Danish DMI-HIRLAM model for Copenhagen
(Baklanov et al. 2005), and the Topographic Vorticity-Mode Mesoscale model TVM
(Hamdi et al. 2005). BEP has also been integrated into the mesoscale model MC2 (Benoit
et al. 1997) in order to simulate heat mitigation strategies in Toronto, Canada (Krayenhoff
et al. 2005). These validations included comparisons for 2-4 day long episodes, as well as
longer periods of up to 14 days within an operational model (Muller 2007), demonstrating
that BEP is able to simulated the UHI and momentum fluxes for longer periods.
BEP is a multi-layer model which directly interacts with the atmospheric model,
representing the impact of the vertical (walls) and horizontal (canyon floors and roofs)
urban surfaces on the momentum, heat and TKE. The impact of the urban surface is
vertically distributed in the urban canopy (with the lowest level at the physical ground).
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