A Numerical Study of Urban Canopy Processes Influence on Local Climate

The WRF (Weather Research and Forecasting) model system is developed by improving the urban canopy scheme and implement of an anthropogenic heat releasing model to simulate the influence of urban canopy processes on urban climate over Nanjing city in both summer and winter. The results indicate that these improvement help WRF model get better simulation results. The thermal influence on urban area is the surface temperature change caused by the urban buildings shadowing and anthropogenic heat releasing. It causes surface temperature decrease in daylight and decrease at night in summer and causes temperature increase both in daylight and at night in winter. The temperature increase in winter is greater than that in summer. The dynamical influence on local climate is the wind speed loss caused by the friction and drag of buildings. The wind speed loss in summer is greater than that in winter, and the loss in daylight is greater than that at night.