THE STUDY OF URBAN CANOPY PARAMETERIZATION SCHEME FOR MM5^*

Based on some advanced urban parameterization schemes for mesoscale model,a new urban canopy parameterization (UCP) for MM5 is developed.The UCP takes into account the impacts of urban infrastructure and anthropogenic activity on the dynamic,thermal structures of urban surface layer and the urban surface energy budget in a more rational way according to conformation of MMS.The UCP is implemented in MM5 and validated by IOP data in 2001 winter BECAPEX and automatic meteorological station data in Beijing area.The results illustrate that UCP versus traditional urban parameterization in MM5,it can make MM5 reproduce main characteristics of winter UBL in Beijing,which include urban heat island and its diurnal evolvement,nocturnal elavated inversion in downtown area,and some dynamic stuctures such as TKE peak at the top of urban canopy,lower wind speed in urban surface layer and so on.