Images from space reveal hot spots in Prague

An image of Prague from June 18 2022 taken by the ECOSTRESS instrument, which is located on the International Space Station

The European Space Agency has released images capturing the recent temperature extremes in a number of European cities, including Prague. The photos, taken from the International Space Station, has revealed heat islands in the densely populated areas of the city, where temperatures reached over 45 degrees Celsius.

Image of Prague and its surroundings from June 18 taken by the ECOSTRESS instrument,  which is located on the International Space Station | Photo: NASA/JPL-Caltech

The land-surface temperature image of Prague was taken in the early afternoon in July, in the midst of one of the worst early summer heatwaves Europe has ever experienced.

The picture was taken by an instrument called ECOSTRESS, installed on board the International Space Station. It demonstrates to what extent the densely built up areas can warm up during the hot summer months and shows how hot the actual surface would feel to the touch.

Among the most affected areas in Prague, glowing bright red on the map, is the Holešovice district by the Vltava River. Michael Pondělíček is a landscape planning expert from Prague’s Institute of Planning and Development:

The ECOSTRESS instrument on the International Space Station | Photo: NASA

“This is mainly because of the old railway station with lots of iron and asphalt and very few trees, so it absorbs a lot of heat from the sun and during the summer months it doesn’t cool down even during the night.

“It is also due to its position at the bottom of the Vltava valley, which is traditionally much warmer and is poorly ventilated.”

Other parts of the city with extremely high land-surface temperature include the area surrounding the O2 Arena in the Vysočany district and the industrial zone in Štěrboholy. The image also reveals the cooling effect of parks, vegetation and water on the city:

“The main cooling corridor in Prague is the Vltava River and its surroundings, which operates day and night. It is also cooler thanks to the water released into the river from the Vranov dam, which helps to keep the temperature in the city down.

“The other significant green oasis is the Olšany cemetery with a number of fully grown trees, which create a specific microclimate. And then of course all the larger parks, such as Petřín, Stromovka, Vítkov Hill and others.”

Image of Brno and its surroundings from June 18 taken by the ECOSTRESS instrument,  which is located on the International Space Station | Photo: NASA/JPL-Caltech

According to Michael Pondělíček, the data obtained from land-surface temperature images can be used in urban planning and infrastructure improvements to mitigate the impacts of heatwaves in the future:

“The most effective measure is planting more trees in the streets and installing all sorts of water features in the city. What also helps is to coat tin roofs with white or silver material that reflects sunlight and doesn’t absorb energy. Then there are other measures, such as installing solar panels on roofs that will absorb the sun’s energy and produce electricity.”

Such solar panels have been already installed on the buildings of the Ministry of Environment, the Czech Technical Engineering Institute and on some of the apartment buildings owned by the city.