ENERGY BALANCE OF AN URBAN CANYON.

Abstract

This study investigates the energy exchanges occurring within an urban canyon. It considers not only the energy balances of each of the canyon component surfaces (walls and floor), but also the balance of the canyon system and of the air volume contained therein. The results are based on measurements conducted in a specially instrumented canyon during a period of fine anticyclonic summer weather in Vancouver, B. C. The timing and magnitude of the energy regime of the individual canyon surfaces are shown to be very different from each other, each being strongly affected by the influence of the canyon geometry on the radiation exchanges. These results are important for understanding the energy loading of buildings and organisms (animal and vegetative), for achieving a physical basis for the understanding of canopy layer microclimates, and for providing realistic lower boundary conditions for urban boundary layer and urban air pollution dispersion modeling.