The efficient urban canopy dependency parametrization (SURY) v1.0 for atmospheric modelling: description and application with the COSMO-CLM model for a Belgian summer
- 1KU Leuven, Dept. Earth and Environmental Sciences, Celestijnenlaan 200E, 3001 Heverlee, Belgium
- 2Deutscher Wetterdienst, Frankfurter Straße 135, 63067 Offenbach, Germany
- 3University of Łodź, Department of Meteorology and Climatology, Narutowicza 88, 90-139 Łodź, Poland
- 4VITO, Flemish Institute for Technological Research, Boeretang 200, 2400 Mol, Belgium
- 5SCK•CEN, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol, Belgium
- 6VMM, Flemish Environmental Agency, Dokter De Moorstraat 24–26, 9300 Aalst, Belgium
Abstract. This paper presents the Semi-empirical URban canopY parametrization (SURY) v1.0, which bridges the gap between bulk urban land-surface schemes and explicit-canyon schemes. Based on detailed observational studies, modelling experiments and available parameter inventories, it offers a robust translation of urban canopy parameters – containing the three-dimensional information – into bulk parameters. As a result, it brings canopy-dependent urban physics to existing bulk urban land-surface schemes of atmospheric models. At the same time, SURY preserves a low computational cost of bulk schemes for efficient numerical weather prediction and climate modelling at the convection-permitting scales. It offers versatility and consistency for employing both urban canopy parameters from bottom-up inventories and bulk parameters from top-down estimates. SURY is tested for Belgium at 2.8 km resolution with the COSMO-CLM model (v5.0_clm6) that is extended with the bulk urban land-surface scheme TERRA_URB (v2.0). The model reproduces very well the urban heat islands observed from in situ urban-climate observations, satellite imagery and tower observations, which is in contrast to the original COSMO-CLM model without an urban land-surface scheme. As an application of SURY, the sensitivity of atmospheric modelling with the COSMO-CLM model is addressed for the urban canopy parameter ranges from the local climate zones of http://WUDAPT.org. City-scale effects are found in modelling the land-surface temperatures, air temperatures and associated urban heat islands. Recommendations are formulated for more precise urban atmospheric modelling at the convection-permitting scales. It is concluded that urban canopy parametrizations including SURY, combined with the deployment of the WUDAPT urban database platform and advancements in atmospheric modelling systems, are essential.