Find out about our research projects below!
Urban climate modeling
Many process-based models that simulate the physics of the urban atmosphere have not been tested against tropical data sets, while empirical models based on existing data sets are biased towards conditions found in mid-latitudes. Our group addresses this knowledge gap by evaluating a wide range of models of various sophistication using energy balance and canopy-layer air temperature data collected in tropical Singapore. The following urban land surface models have been tested:
WRF-BEP-BEM multi-layer urban scheme: 1km resolution, coupled (Sanchez et al., 2021)
CLM, SURFEX, TERRA_URB (COSMSO-CLM) and SUEWS multi-model comparison, uncoupled (Demuzere et al., 2017).
TEB/ISBA (SURFEX), uncoupled (Harshan et al., 2017)
ENVI-met Version 3.1, uncoupled (Roth and Lim, 2017)
Integrated, multi-dimensional measurements of temperature, humidity and carbon dioxide over different land uses
The overall aim of this project is to assess how land cover and built form affect climate variables important for the well-being of people living in Singapore. Climate data will be collected using a network of fixed wireless stations, and vertical sampling using an UAV at the fixed stations to provide a limited characterisation of the 3-D nature of the urban canopy layer (i.e. the lowest layer of the urban atmosphere). The observations will be integrated to demonstrate how air temperature, humidity and CO2 concentration are influenced by spatial variations of different types of land cover and utilization, and in the course of seasonal change of meteorological conditions. (Team: Minghong Yu and Matthias Roth)
Urban heat island studies
A number of urban heat island (UHI) studies have been carried out, going back to Winston Chow's work as a Masters student in 2003. That year-long study used measurements from four carefully selected urban and one ‘rural’ site to highlight the diurnal and seasonal UHI variability and provide first indications of the dependence of the UHI magnitude on the nature of the built environment and weather (Chow and Roth, 2006). Since then, the sensor network to measure the canopy-layer air temperature and humidity has expanded across the island. Analysis of six years of data from 20 measurement locations provide the basis for the possibly most extensive UHI study in a tropical city. The results detail the spatio-temporal characteristics of the UHI across local climate zones under different weather conditions (Roth et al., 2022). A number of smaller UHI projects have recently been completed with data analysis ongoing.
A good understanding and assessment of UHI development and parameters influencing its magnitude in Singapore and elsewhere has application for current and future cities. The present results can be used to support the development and evaluation of urban climate models, develop urban planning policies and improve local weather forecasts and the delivery of integrated urban services.
Direct measurement of energy balance and carbon dioxide exchange over a suburban area
Urbanization strongly affects the surface partitioning of the incoming energy delivered by the sun into radiation, heat and mass fluxes. The nature of this partitioning defines the particular microclimate of a location. Behavioural patterns of people further affect the various fluxes through adding anthropogenic heat to the energy balance and the emission of carbon dioxide from human metabolism and fuel combustion. This project quantifies the energy and carbon dioxide exchange over a suburban neighborhood applying micrometeorological methods (eddy covariance approach), in combination with models to determine the precise nature of the urban surface influencing the measurements. (Team: Matthias Roth, Erik Velasco and Christer Jansson)