On the Urban Canopy Effects in Regional Climate Simulations—An Inter-Model Comparison and Potential for Prediction

To assess the impact of cities and urban surfaces on climate, the modeling approach is often used with inclusion of urban parameterization in land-surface interactions. This is especially important when going to higher resolution, which is common trend both in operational weather prediction and regional climate modelling. Inclusion of urban related effects can differ significantly across the land-surface models and urban canopy parameterizations. For adaptation and mitigation measures applied in big cities, especially in connection to climate change perspective, it is important to assess this uncertainty as well as to analyse the effects, which can affect air quality situation within the cities. These are main tasks of the new project URBI PRAGENSI. We performed experiments to assess urban effects on climate over central Europe for the decade 2001–2010, using two regional climate models (RegCM4 and WRF) in 10 km resolution driven by ERA-Interim reanalyses, three surface schemes (BATS and CLM4.5 for RegCM4 and Noah for WRF) and five urban canopy parameterizations available: one bulk urban scheme, three single layer and a multilayer urban scheme.