Modelling Urban Meteorology With Mm5
Air pollution can be influenced by urban as well as synoptic-scale meteorological processes. As a result of different land cover characteristics, presence of buildings and energy consumption, meteorology of urban areas can be significantly modified from that of the rural surroundings. It is important to understand these differences in order to explain the causes of air pollution events over urban and regional scales. The MM5 meteorological model has been applied to a winter and summer episode period in the urban area of London. The model performance in the urban environment was evaluated by comparison to measurements and through a detailed sensitivity study of model configuration and physics schemes for the air pollution episode period 17-23 February 2003. The present study was the first research application of MM5 to a large UK city. It was also the first MM5 evaluation based on a detailed sensitivity analysis carried out for London.
Left figure: the temperature distribution map produced by the Pleim-Xiu land surface model clearly demonstrates the ability of the model to respond to the temperature difference between the urban area of London and the surrounding areas. Right figure: surface temperature at Northolt predicted by Gayno-Seaman (GS) and GS with added anthropogenic heating. A significant improvement in the prediction of surface temperature for the urban stations of Northolt was achieved after the incorporation of anthropogenic heating.
Acknowledgements & collaborations:
This research was funded by the European Commission (FUMAPEX FP5 project). BADC and DEFRA are thanked for providing access to meteorological and air quality data respectively. The collaboration of the UK Met Office is also appreciated.
Selected references:
Kukkonen, J., M. Pohjola, R. S. Sokhi et al., 2005. Analysis and evaluation of selected PM10 air pollution episodes affecting four European cities: Helsinki, London, Milan and Oslo. Atm. Environ. 39, 2759-2774. Fragkou, E., 2005. Application of a mesoscale model to analyse the meteorology of urban air pollution episodes. Ph.D. thesis, University of Hertfordshire, UK.