Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Atmos. Chem. Phys., 11, 2951-2972, 2011
© Author(s) 2011. This work is distributed under
the Creative Commons Attribution 3.0 License.
Research article
30 Mar 2011
Sensitivity of mesoscale model urban boundary layer meteorology to the scale of urban representation
D. D. Flagg1,* and P. A. Taylor1 1York University, Toronto, Ontario, Canada
*now at: Meteorologisches Institut, Universität Hamburg, Hamburg, Germany
Abstract. Mesoscale modeling of the urban boundary layer requires careful parameterization of the surface due to its heterogeneous morphology. Model estimated meteorological quantities, including the surface energy budget and canopy layer variables, will respond accordingly to the scale of representation. This study examines the sensitivity of the surface energy balance, canopy layer and boundary layer meteorology to the scale of urban surface representation in a real urban area (Detroit-Windsor (USA-Canada)) during several dry, cloud-free summer periods. The model used is the Weather Research and Forecasting (WRF) model with its coupled single-layer urban canopy model. Some model verification is presented using measurements from the Border Air Quality and Meteorology Study (BAQS-Met) 2007 field campaign and additional sources. Case studies span from "neighborhood" (10 s ~308 m) to very coarse (120 s ~3.7 km) resolution. Small changes in scale can affect the classification of the surface, affecting both the local and grid-average meteorology. Results indicate high sensitivity in turbulent latent heat flux from the natural surface and sensible heat flux from the urban canopy. Small scale change is also shown to delay timing of a lake-breeze front passage and can affect the timing of local transition in static stability.

Citation: Flagg, D. D. and Taylor, P. A.: Sensitivity of mesoscale model urban boundary layer meteorology to the scale of urban representation, Atmos. Chem. Phys., 11, 2951-2972,, 2011.
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