Urban warming and energy consumption in Tokyo metro area

This paper reports the results of field observation and three-dimensional simulation of urban warming in Tokyo metropolitan area. The three-dimensional governing equations in an urban atmospheric boundary layer were formulated by virtue of vorticity-velocity vector potential method. Particular attention was focused on the representation of a buoyancy term in equation of motion in the vertical direction, thereby describing the crossover and stratification effects near the ground surface. The vorticity-velocity potential method is superior from the view point of numerical stability and suitable for the simulation of an urban heat island. The authors first made a survey on the energy consumption in Tokyo metropolitan area. Next, the three-dimensional simulations were carried out using these data. The simulation results were then compared with the data of field observation of the surface temperature by automobiles. Further future prediction of urban warming was performed when the energy consumption rate is increased five times as large as the present rate, which will correspond to the year 2030 if the present consumption rate were maintained until then