On the Formulation and Implementation of Urban Boundary Conditions for Regional Models
“How can we assimilate detailed information from the urban canopy into regional models?” That is the question to be addressed in this contribution. In regional air quality models the exchange of pollutants between the surface and the atmosphere is generally represented by an emission source term and a deposition term. It is common practise that emissions generated at the surface are instantaneously diffused into the grid cells. Many of the dynamics of the urban canopy are not represented in regional models despite the fact that we have a lot of detailed information about these dynamics, e.g. on the canopy structure and roughness elements, on traffic emissions and on street canyon dynamics (Vardoulakis et al., 2003). In particular road transport emissions can be described hourly as a function of the road type, vehicle type, fuel type, traffic volume, vehicle age, trip length distribution and the actual ambient temperature (Mensink et al, 2000).
KeywordsRoad Segment Street Canyon Turbulent Eddy Urban Canopy Benzene Concentration
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