Urban Heat Island Phenomena and their Causing Factors : A Case Study of Tokyo Metropolis

Urban heat island phenomena, which are known as high temperature occurrences in the central part of a city, would be estimated to become much greater in a large city as Tokyo. There have been many studies on urban heat island phenomena in the field of meteorology, climatology, architecture and city planning. Thus overall feature of urban heat island phenomena including their mechanisms became clear from observational and numerical studies. However, the detailed characteristics of urban heat islands such as the long term warming trends of urban temperatures and the seasonal/diurnal variations in local scale temperature distribution are not fully discussed. This paper aims at clarifying the spatial and temporal structure of urban heat island phenomena in Tokyo metropolitan area as a case study in connection with anthropogenic energy consumption and diurnal wind fields based on the high density meteorological observational system in Tokyo Metropolis.