2017 Volume 13 Pages 59-62
Heat island intensity approaches the maximum during urban Phase A period, which constitutes a few hours around sunset when radiative cooling primarily determines the temperature decrease. To evaluate the thermal inertia of urban and rural canopy layer, we suggested a local effective thermal inertia (LETI) that corresponds to a canopy layer thermal inertia, excluding advection effects caused by such as heat island circulation, and estimated the value by observing a 30-min temperature variation and radiation flux when clouds appeared during night. The urban area LETI is approximately two times higher than the rural value. LETI has a close relationship to the cooling rate in Phase A and is an important value for urban canopy layer thermal inertia.
