Exploring the heat balance characteristics in Shanghai by using the WRF model coupled with Local Climate Zone scheme

Abstract

Clarifying the characteristics of the heat balance mechanism of urban space atmosphere is crucial for developing effective countermeasures to mitigate urban heat island (UHI) effect. This study focused on Shanghai, using the Weather Research and Forecasting (WRF) model coupled with the local climate zone (LCZ) scheme to simulate the urban climate and analyze the characteristics of the sensible heat balance components—advection, turbulent diffusion, and anthropogenic heat release—within different regions of Shanghai. The key findings are: 1) the characteristics of advection components in different regions indicate that sea breezes and lake breezes both play significant roles in reducing the air temperature in Shanghai, with sea breezes being more effective; 2) the vertical gradient of wind velocity in the upper air of inland regions increases more than that of coastal regions, leading to a significantly lower net sensible turbulent diffusion component of urban space atmosphere in inland regions compared to coastal regions; 3) the distribution of sensible anthropogenic heat release (SAH) in Shanghai is generally correlated with LCZs, with the SAH is significantly higher in open high-rise and heavy industry types areas compared to other areas. Furthermore, this study determined the UHI mitigation countermeasures for different areas based on the heat balance characteristics of urban space atmosphere in different regions of Shanghai, contributing to the improvement of the urban thermal environment conditions.