Space–time Analysis of the Earth's Surface Temperature, Surface Urban Heat Island and Urban Hotspot: Relationships with Variation of the Thermal Field in Andalusia (Spain)

Understanding just how the increase in the Earth's Surface Temperature (LST) is related to alterations of the urban climate —Surface Urban Heat Island (SUHI) or Urban Hotspots (UHS)— and with the deterioration of cities´ environmental quality has become a great challenge. Societies worldwide seek actions that might break these trends and improve the quality of life of local inhabitants in the face of climate change. In this research, and with the help of Sentinel 3 satellite images (day and night), the space–time variability of the LST and the SUHI over the metropolitan areas of the capitals of Andalusia (Spain) during the year 2021 was studied to evaluate how these variables, together with the Land Use/Land Cover (LULC), may have influenced the variability of the UHS and the level of thermal comfort according to the Thermal Field Variance Index (UTFVI). As results, an important spatial variability of the LST, SUHI, UHS, and the different classes of UTFVI is reported. The diurnal UHS are found mainly in rural areas without vegetation, whereas the night UHS are distributed in urban areas with impervious surfaces.