Comparison of surface heat balance in three cities in Taiwan using Terra ASTER and Formosat-2 RSI data

In order to investigate the influences of the city scale, usage, topography, and climate on surface heat balance, the authors compared the surface heat balance for three urban areas in Taiwan, namely, Kaohsiung City, Taichung City, and Tainan City, estimated using ASTER and Formosat-2 data. The net radiation was in a similar range in all three study areas because the cities are in close proximity to each other. Tainan City released 60–70% of the sensible heat flux of the other cities because of its smaller size. Taichung City, which is located in a basin, exhibited the largest sensible heat flux, due to the radiation cooling during the night before the observation. Anthropogenic heat discharge clearly decreased the storage heat flux in certain industrial areas in Kaohsiung City and Taichung City, while the small scale urban functions moderated the variation of storage heat flux in Tainan City. These results imply that the terrain around a given city as well as the scale of urban activity significantly affect the heat balance in the cities.