On the comparison of urban environment effects parameterization

The impact of cities and urban surfaces on weather, climate, and air-quality, is often assessed using modeling approach. In regional scale models, an urban parameterization in land-surface interactions can be included. This is especially important when going to higher resolution, which is common trend both in operational weather prediction and regional climate modelling as well as in coupled chemistry-transport modelling. However, model description of urban canopy related meteorological effects can significantly differ especially in the underlying surface models and the urban canopy parameterizations, which results in a certain uncertainty. To assess this uncertainty is important for adaptation and mitigation measures of the urban effects, which is often applied in the big cities, especially in connection to climate change perspective, but it is important in operational prediction as well. This is one of the main task of the project OP-PPR Proof of Concept UK as well as project Urbi Pragensi, where in addition to climate effects air-quality control aspects are studied. Effects of cities on urban and rural areas are evaluated, the impact of complexity of urban parameterization on the model results improvement is discussed with regard to demands on computational resources as well.