Exploring Thermal Regimes in Urban Heating using DUCT City-scale Modeling

This study examines the heat and stability patterns of the urban boundary layer in cities. It emphasises the impact of urbanisation and anthropogenic activities on atmospheric characteristics and provides insights into stability implications for the urban environment. Using a high-resolution, sub-kilometre scale city-wide numerical modelling framework, part of the Digital Urban Climate Twin (DUCT), examines the variability of thermal regimes within the boundary layer. The findings reveal distinct thermal regimes influenced by diurnal local circulations, urban heat island effects, and moisture availability. During the daytime, convective turbulence dominates due to strong surface heating, while at night, stable stratification may develop, but local heating sources (e.g., anthropogenic heat) disrupt stability. The study highlights that stability profiles are crucial in determining outdoor comfort and air ventilation under the influence of the transilient nature of wind and thermo-moisture fields at a city scale. These findings are essential for urban climate adaptation strategies and for improving local weather forecasting.