Sea surface temperature impacts on tropical urban environment: A WRF modelling investigation

In recent times urban planners in dense cities have realized the negative impact of the urban heat island (UHI) phenomenon and its strong relation with climate change. Sea Surface Temperature (SST) significantly impacts the coastal urban environment, and a systematic error may adversely impact an urban thermal assessment. This study examines the role of SST during representative months in Singapore. It is found that the reanalysis SST synthesized with satellite SST indicates an improvement in RMSE up to 0.9 °C across representative seasons at station locations within the urban canopy. The systematic SST error leads to a variation in estimated UHI intensity by up to 0.3 °C, demonstrating its non-negligible impact. The highest spatial mean UHI intensity (2.9 °C) occurs at midnight in October while the lowest UHI (1.4 °C) occurs in February. The influence of sea breezes (under weak synoptic patterns in the Inter-Monsoon seasons) is analyzed to show relevant impact in the area close to the coastline. The results provide insights into the potential future impact of global warming and rising SST on Singapore's thermal environment. Adequate urban planning can promote ventilation paths starting in the coastline to further remove urban heat in inland locations.