Space-Time Characteristics of Air Temperature Distribution and Heat Island Situation in Osaka City

Abstract

In recent years a marked "heat island" phenomenon has been noted in urban areas, but with specific local characteristics, so that specific procedures for climate moderation will be needed for each region. The characteristics of air temperature distribution in summer are different in each region and time zone. The air temperature of regions in low latitudes is not necessarily high in August. In the daytime, the temperature rise is in some cases greater in the suburbs than in the center of the city. The study of the time-space distribution of energy supply in Osaka City revealed that the electric power supply amount per unit of floor area differs considerably between central commercial and business districts and suburban residential districts. Data obtained through the Heat Island Measurement Network of Osaka City showed that the air temperature rose from the west to the east in the daytime. On the other hand, at night and in the early morning, the temperature was highest in the center of the city. The study demonstrates the relationship between these typical urban areas and the heat island phenomenon and suggests that a detailed menu that takes account of the character of each area is necessary. In order to take more effective measures, it is important to characterize each area and to bring entrepreneurs and residents to understand the need for them.