Recorded presentationJ24.3
Application of an integrated WRF/urban modeling system to urban environmental problems
Fei Chen, NCAR, Boulder, CO; and M. Tewari, Y. Liu, J. Dudhia, S. G. Miao, A. Martilli, S. Grossman-Clarke, J. K. Ching, and H. Kusaka
Today's mesoscale numerical weather prediction (NWP) models are routinely executed at a grid spacing of 1~4 km and their output are used to provide meteorological conditions for air quality, transport and dispersion model forecast for urban areas. It is critical for these high-resolution NWP models to capture influences of urban forcing on wind, temperature, and humidity in the atmospheric boundary layer structures, so that air dispersion and quality models will benefit from improved prediction of the urban meteorological conditions. To bridge the gaps between traditional mesoscale modeling (with 101-km grid spacing) and microscale modeling (with 101-m grid spacing), we are developing an integrated urban modeling system coupled to the Weather Research and Forecast (WRF)/Noah land surface model as a community tool to address urban environmental issues and to study urban-atmospheric interactions. This urban modeling system consists of different methods to parameterize urban land use, ranging from a simple bulk parameterization to a sophisticated multi-layer urban canopy model that directly interacts with the atmospheric boundary layer with heat, momentum, and moisture exchange. We will describe the application of this urban modeling system to various metropolitan areas (Houston, Oklahoma City, Beijing, Taipei, Salt Lake City, etc.) and its evaluation against urban-scale observations. The results demonstrated that representing the urban heat island effects is critical to correctly capture not only differential heating caused by urban surface heterogeneities, but also mesoscale wind fields modified by urban areas. Also, it is clear that high-resolution urban phenology and anthropogenic heating data are important input to the urban models. In this paper, the model sensitivity to gridded fine-scale data sets of buildings, vegetation cover, and other morphological features in metropolitan areas (such as those developed under the National Urban Database and Access Portal Tools (NUDAPT)) will be discussed.
Joint Session 24, Modeling Tools for Urban and Complex Terrain Environments
Thursday, 15 January 2009, 3:30 PM-5:00 PM, Room 124A
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