Impact of sea breeze on Urban Heat Island: A Case Study in a coastal city, Singapore

Rapid urbanization has exacerbated the Urban Heat Island (UHI) effect. In coastal cities, sea breeze serves as a potential mechanism to mitigate this issue. However, existing research often overlooks the interaction between sea breeze and monsoon. This study addresses this gap by investigating the cooling effect of sea breeze in Singapore, during the Northeast (NE) and Southwest (SW) monsoon. First, a novel sea breeze filter method is proposed, and two typical days in 2023 are selected, representing the NE and SW monsoons, respectively. Secondly, the Weather Research and Forecasting (WRF) model is utilized, incorporating with the Local Climate Zone (LCZ). The WRF model is validated against observational data before being used to calculate the wind and temperature distribution among Singapore. Finally, a spatial zoning analysis of Singapore is conducted based on the simulation results. The results are presented as follows: 1) Based on the numerical simulation results, the Northeast monsoon exhibits a stronger cooling effect than the Southwest monsoon; 2) Cooling capacity is higher in urban areas during the Northeast monsoon, while in the Southwest monsoon, the cooling effect is stronger in rural areas. This study can provide a scientific foundation for urban planning and sustainable development in tropical coastal cities.