Urban climate effects of artificial heat sources and ground shadowing by buildings

Simulations are presented for the effects of artificial heat sources and ground shading by buildings on air temperature variations in the urban canopy layer. An idealized urban cluster composed of repeated street canyons oriented east‐west with an aspect ratio of 0.5 is used to evaluate these effects. The simulations by the cluster thermal time constant model show that a daily mean artificial heat flux of 11 Wm −2 causes an almost invariant temperature rise of 0.7 K around‐the‐clock. Conversely, increasing the shade area in the streets by means of vertical screens fitted at the building roof‐level can produce a pronounced temperature lowering at midday.