Multi-model comparison of urban heat island modelling approaches

Autor: J. Karlický, P. Huszár, T. Halenka, M. Belda, M. Žák, P. Pišoft, J. Mikšovský
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Atmospheric Chemistry and Physics, Vol 18, Pp 10655-10674 (2018)
Druh dokumentu: article
ISSN: 1680-7316
1680-7324
DOI: 10.5194/acp-18-10655-2018
Popis: Cities are characterized by different physical properties of surface compared to their rural counterparts, resulting in a specific regime of the meteorological phenomenon. Our study aims to evaluate the impact of typical urban surfaces on the central European urban climate in several model simulations, performed with the Weather Research and Forecasting (WRF) model and Regional Climate Model (RegCM). The specific processes occurring in the typical urban environment are described in the models by various types of urban parameterizations, greatly differing in complexity. Our results show that all models and urban parameterizations are able to reproduce the most typical urban effect, the summer evening and nocturnal urban heat island, with the average magnitude of 2–3 °C. The impact of cities on the wind is clearly dependent on the urban parameterization employed, with more simple ones unable to fully capture the wind speed reduction induced by the city. In the summer, a significant difference in the boundary-layer height (about 25 %) between models is detected. The urban-induced changes of temperature and wind speed are propagated into higher altitudes up to 2 km, with a decreasing tendency of their magnitudes. With the exception of the daytime in the summer, the urban environment improves the weather conditions a little with regard to the pollutant dispersion, which could lead to the partly decreased concentration of the primary pollutants.
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