Calculation of Air Temperatures above the Urban Canopy Layer from Measurements at a Rural Operational Weather Station

Abstract

Urban canopy models (UCMs) are being used as urban-climate prediction tools for different applications including outdoor thermal comfort and building energy consumption. To take advantage of their low computational cost, UCMs are often forced offline without being coupled to mesoscale atmospheric simulations, which requires access to meteorological information above the urban canopy layer. This limits the use of UCMs by other scientific and professional communities, such as building engineers and urban planners, who are interested in urban-climate prediction but may not have access to mesoscale simulation results or experimental meteorological data. Furthermore, the conventional offline use of UCMs neglects the fact that the urban boundary layer can be affected by the surface and that the same forcing conditions may not be suitable for studying different urban scenarios. This paper presents a physically based and computationally efficient methodology to calculate forcing air temperatures for UCMs from meteorological data measured at operational weather stations. Operational weather stations are available for most cities in the world and are usually located in open areas outside the cities. The proposed methodology is satisfactorily evaluated against mesoscale atmospheric simulations and field data from Basel, Switzerland, and Toulouse, France.