VARIFICATION OF SUMMER TEMPERATURE DECREASE ASSOCIATED WITH THE INSTALLATION OF COOL ROOF IN TOKYO METROPOLIS

Abstract

 In order to verify the realistic temperature reduction effect of cool roofs, we conducted a more realistic weather simulation than previous studies, using a WRF model that reflects the urban geometric parameters of a real city, and varying the reflectance and diffusion rate step by step. In the case of cool roofs installed only in the 23 wards of Tokyo, it was confirmed that the amount of temperature reduction during the summer season increased as the reflectance and diffusion rate increased, and that the effect extended beyond the installation area. When the reflectance of all roof surfaces was 85%, the daily mean temperature decreased by about 0.32°C and the daily maximum temperature decreased by about 0.38°C. The correlation between the area of the cool roof and the temperature reduction was confirmed, indicating the importance of setting detailed urban geometric parameters.