A top-down methodology for developing diurnal and seasonal anthropogenic heating profiles for urban areas

A generalized approach for estimating season-specific diurnal profiles of anthropogenic heating for cities is presented. Each profile consists of heat released from three components: building sector, transportation sector, and metabolism. In turn, the building sector is divided into heat released from electricity consumption and heat released from heating fuels such as natural gas and fuel oil. Each component is developed separately based on a population density formulation. The profiles are based on commonly available data resources that are mapped onto the diurnal cycle using seasonal profile functions. Representative winter and summer weekday profiles are developed and presented for six large US cities. The diurnal profiles have morning and evening peaks, with summertime maxima up to 60 W m(-2). Anthropogenic heating in winter is generally larger, with maxima up to 75 W m(-2). While these analyses were carried out at the city-scale the paper discusses how the same data sources could be applied at scales down to the individual census tract (or traffic analysis zone), resulting in high spatial resolution profiles and larger maxima corresponding to higher population densities in the urban core. Based on our analysis of San Francisco we find that the urban core region may have a daytime population density that is 5-10 times that of the city-scale value. Hence, the corresponding anthropogenic heating values in the urban core will be 5-10 times the magnitudes of the city-scale values presented in this paper. (C) 2004 Elsevier Ltd. All rights reserved.