On the comparison of urban canopy effects parameterisation

Abstract

To assess the impact of cities on climate, modelling is used with inclusion of urban parameterisation which is important when applying higher resolution. It is essential to assess uncertainties of urban effect parameterisations. To estimate this we performed experiments with available settings of urban canopy models over central Europe for 2001-2010. We have used RegCM4 and WRF in 10 km resolution, three surface schemes and five urban canopy parameterisations available. Selected WRF options were tested for urbanised weather prediction in 3 km resolution to show the effect in a single extreme case study. Urban heat island was detected in all simulations, for summer night the strongest on average was a few °C. We demonstrate that for cities like Prague it can in extremes approach 5°C, for larger city such as Budapest it is 8°C. In weather prediction mode, WRF model captured these effects in a single heat wave with selected parameterisations well.