Numerical simulation of the anthropogenic heat effect on urban boundary layer structure

In this paper, several methods of incorporating anthropogenic heat release into the boundary layer are compared. The best scheme was one that included anthropogenic heat release in both the surface energy balance equation and the thermodynamic equations. In addition, it included diurnal variations and a distribution of heat based on building concentrations. We further investigated the influence of anthropogenic heat release on urban boundary layer structure and the urban heat island, and found that the contribution of anthropogenic heat release to the urban heat island is greatest in the evening and at night, and least at noon. The daily average contribution ratio of anthropogenic heat to urban heat island intensity in the winter is 54.5%, compared with just 43.6% in the summer. Anthropogenic heat strengthens the vertical movement of urban surface air flow, changing the urban heat island circulation. It also makes the urban boundary layer more turbulent and unstable, especially in the morning and evening. The degree of influence of anthropogenic heat release on local boundary layer structure depends on its importance to the surface energy budget.