URBAN4: AN Urban Canopy Layer Surface Energy Balance Climate Model

URBAN4, an urban canopy layer surface energy balance model, is developed in this research. The model is capable of simulating energy fluxes and surface temperature in irregular and complex urban settings. This is achieved with a unique hierarchial raster structure and its raster based method of deriving view factors, a new method developed in this research. After the model was established it was tested for its response to various urban geometry, surface property and seasonal (meteorological condition) changes. Part of the CBD area and a residential area in downtown Los Angeles were selected to test the model's ability to simulate realistic settings. Although the model has not validated by field observations, the results are consistent with published measurement studies.