Website
https://yceo.yale.edu/research/global-surface-uhi-explorer
Description
The urban heat island (UHI) effect - the phenomenon of higher temperatures in urban environments - is one of the most well-known consequences of urbanization on local climate. We develop the simplified urban-extent (SUE) algorithm, a new algorithm to estimate the urban heat island (UHI) intensity at a global scale. This algorithm is implemented on the Google Earth Engine platform and uses satellite-derived images to calculate the surface UHI intensity for over 9500 urban clusters covering 15 years, making this the most comprehensive global UHI database. The data are validated against previous multi-city studies and then used to estimate the diurnal, monthly, and long-term variability in the surface UHI in different climate zones. The global mean surface UHI intensity is 0.85 °C during daytime and 0.55 °C at night. Cities in arid climate zone, in particular, show unique diurnal and seasonal patterns, with higher nighttime surface UHI intensity and two peaks throughout the year. The diurnal variability in surface UHI is highest for the equatorial climate zone (0.88 °C) and lowest for the arid climate zone (0.53 °C). The inter-seasonal range is highest in the snow climate zone and lowest in equatorial climate zone. We also investigate the long-term change in the UHI intensity over 15 years and find an increase in the daytime UHI intensity at the rate of 0.03 °C per decade.
We make our new database easily accessible by designing an interactive web portal for the data. The application is built on the Google Earth Engine platform and allows users to query the UHI data of urban areas using a simple interface. Users can generate charts showing the seasonal and long-term trend for individual urban clusters and can then download the data from the web portal. The link to the application and further information about it can be found at: https://yceo.yale.edu/research/global-surface-uhi-explorer
Included in
A Global Database of Surface Urban Heat Island Intensity
The urban heat island (UHI) effect - the phenomenon of higher temperatures in urban environments - is one of the most well-known consequences of urbanization on local climate. We develop the simplified urban-extent (SUE) algorithm, a new algorithm to estimate the urban heat island (UHI) intensity at a global scale. This algorithm is implemented on the Google Earth Engine platform and uses satellite-derived images to calculate the surface UHI intensity for over 9500 urban clusters covering 15 years, making this the most comprehensive global UHI database. The data are validated against previous multi-city studies and then used to estimate the diurnal, monthly, and long-term variability in the surface UHI in different climate zones. The global mean surface UHI intensity is 0.85 °C during daytime and 0.55 °C at night. Cities in arid climate zone, in particular, show unique diurnal and seasonal patterns, with higher nighttime surface UHI intensity and two peaks throughout the year. The diurnal variability in surface UHI is highest for the equatorial climate zone (0.88 °C) and lowest for the arid climate zone (0.53 °C). The inter-seasonal range is highest in the snow climate zone and lowest in equatorial climate zone. We also investigate the long-term change in the UHI intensity over 15 years and find an increase in the daytime UHI intensity at the rate of 0.03 °C per decade.
We make our new database easily accessible by designing an interactive web portal for the data. The application is built on the Google Earth Engine platform and allows users to query the UHI data of urban areas using a simple interface. Users can generate charts showing the seasonal and long-term trend for individual urban clusters and can then download the data from the web portal. The link to the application and further information about it can be found at: https://yceo.yale.edu/research/global-surface-uhi-explorer
https://elischolar.library.yale.edu/dayofdata/2018/posters/14