Temporal dynamics of the urban heat island of Singapore

TLDR

Green space extent and anthropogenic heat influence the urban heat island. The study examines the temporal variability of Singapore’s canopy‑level UHI across different time scales using one year of observations. Temperature data from commercial, CBD, high‑rise, and low‑rise areas were compared to rural reference data and analyzed relative to meteorological variables and land use, and the results were compared with UHI data from other tropical and mid‑latitude cities. Peak UHI magnitude occurs 3–4 h after sunset in commercial areas; higher intensities occur during May–August southwest monsoon with up to ~7 °C in commercial areas; seasonal precipitation variations explain some urban–rural cooling differences; no clear relationship between urban geometry and UHI intensity, with intra‑urban temperature variations influenced by green space and anthropogenic heat. © 2006 Royal Meteorological Society.

Abstract

The temporal variability of the canopy-level urban heat island (UHI) of Singapore is examined for different temporal scales on the basis of observations during a 1-year period. Temperature data obtained from different urban areas (commercial, Central Business District (CBD), high-rise and low-rise housing) are compared with ‘rural’ reference data and analysed with respect to meteorological variables and differences in land use. The results indicate that the peak UHI magnitude occurs 3–4 h (>6 h) after sunset in the commercial area, (at other urban sites). Higher UHI intensities generally occur during the southwest monsoon period of May–August, with a maximum of ∼7 °C observed in the commercial area under ideal meteorological conditions. Variations in seasonal precipitation explain some of the differences in urban–rural cooling. No clear relationship between urban geometry and UHI intensity can be seen, and intra-urban variations of temperature are also shown to be influenced by other site factors, e.g. the extent of green space and anthropogenic heat. Lastly, results from the present study are compared with UHI data from other tropical and mid-latitude cities. Copyright © 2006 Royal Meteorological Society.