LOS ANGELES, July 3 (Xinhua) -- NASA's Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) mission has measured Earth's surface temperature from space at different times of the day, and mapped the ground temperature of four European cities during the heat wave recently.
According to a release of NASA's Jet Propulsion Laboratory (JPL) on Tuesday, ECOSTRESS measured the surface of Rome, Paris, Madrid and Milan in the mornings of June 27 and June 28.
The images, with hotter temperatures appearing in red and cooler temperatures in blue, show how the central core of each city is much hotter than the surrounding natural landscape.
It was due to the urban heat island effect, a result of urban surfaces storing and re-radiating heat throughout the day, according to JPL.
The fact that surface temperatures were as high as 25-30 degrees Celsius in early morning indicates that much of the heat from previous days was stored by surfaces with high heat capacity, such as asphalt, concrete and water bodies. It was unable to dissipate before the next day, said JPL.
The trapped heat resulted in even higher midday temperatures, in the high 40s Celsius in some places, as the heat wave continued, according to JPL.
ECOSTRESS, launched to the International Space Station (ISS) last summer, is a new NASA Earth science mission to study how effectively plants use water by measuring their temperature from space.
Although its primary objective is to monitor the health of plants, ECOSTRESS can also detect heat events such as the one much of Europe just experienced, according to JPL.
