Dr. Susana Del Pozo has developed a research stay abroad dealing with the Urban Heat Island (UHI) effect.
During her stay at INSA, Dr. Susana Del Pozo has studied the Urban Heat Island effect (UHI) produced in Strasbourg with the collaboration of climatologists, surveyors and professionals from the Image Processing and Remote Sensing Service (SERTIT) and the French National Center for Scientific Research. She spent 2 months at INSA from October to December 2019 and the collaboration continues within the framework of a research project dealing with the mapping of the UHI effect in Strasbourg.
UHI occurs when a significant variation in temperatures between urban areas (higher temperature) and rural areas (lower temperature) is observed. The main cause is the modification of natural land surfaces such as forests, riverbanks etc. by artificial ones such as buildings, sidewalks, asphalt, etc. that trap heat during the day and release it at night. But in addition to this cause, it is the human and industrial activity. This effect becomes more evident at night and in summer and winter time.
With the aim of mapping the UHI effect produces in the metropolitan area of Strasbourg, Susana has focused on satellite image processing from the thermal spectrum. She chooses ASTER and MODIS sensors to obtain land surface temperatures since both sensors offer thermal information at night and are onboard the same satellite platform, TERRA. In this way, it is possible to compare results obtained from both since they acquire information h at the same time of the day although at different spatial and temporal resolution.
In addition, land surface temperatures from both satellites have been compared with temperatures measured at ground level in different places of the city ranging from pure artificial to vegetated areas.
This triple comparative has served not only to analyze the accuracy of satellite data but also to discover the close connection that urban geometry has with temperature behavior as well as to its representativeness. The temperature representativeness depends on the type of land cover and its 3D geometry and therefore, depending on what type of land coverage is analyzed, the temperature must be analyzed taking into account a greater or lesser area extension.
Finally, the behavior of land surface temperature was analyzed when: (1) moving from urban to outskirts, (2) when moving from one local climate zone to another and (3) for each individual meteorological site where temperatures at ground level were measured.
The research collaboration still continues during the month of December 2019 so, more news will come.