Numerical study on the climatic effects of building morphology: A case study of Shanghai, China

The impact of urbanization on local climate involves two processes: changes in surface material and changes in spatial morphology. These two processes significantly alter the surface properties of urban areas. Compared to changes in surface material, the changes in urban spatial morphology have a more complex impact on the dynamic and thermal processes in urban areas. This paper examines Shanghai, using the WRF model coupled with urban morphological parameters to conduct simulations of winter and summer from 2016 to 2020. Our analysis focused on the impact of building morphology on near-surface meteorological elements, surface energy balance, boundary layer structure, and summer precipitation characteristics in Shanghai. The results indicate that building morphology affects surface energy balance by influencing urban canopy radiation processes. Buildings cause the city to absorb more radiant energy during the day, increasing both sensible heat and stored heat in the city. At night, this stored heat is released, with the release being more complete during winter. Consequently, Shanghai experiences a notable increase in near-surface air temperature and a rise in boundary layer height. Building morphology also affects summer precipitation in Shanghai, increasing both the amount of precipitation and the number of rainy days, particularly light rain days.