Satellite data show different trends for the federal states („Bundeslaender")
The nights in the German federal states („Bundesländer") have been getting brighter and brighter - but not everywhere at the same rate and with one peculiar exemption: light emissions from Thuringia decreased between 2012 and 2017.
This is the result of a recent study by scientists Chris Kyba and Theres Küster from the GFZ German Research Centre for Geosciences together with Helga Kuechly from "Luftbild - Umwelt - Planung, Potsdam". Kyba and colleagues published the study in the International Journal of Sustainable Lighting IJSL. This week, they updated the maps by including the 2017 data from a satellite-born instrument.
The team measured the change of light emissions for every German state, studying both the lit area and total radiance. The trends in the lit area show a clear distinction between East and West. The lit area of the states of the former GDR including Berlin stayed basically the same (growth less than 1 per cent), whereas the states in the western part of Germany increased in the area that is lit in the night.
The lit area in Thuringia decreased by about 7%. With respect to the intensity of the lighting, the picture is more complex. Large areas in both East and West Germany show only marginal changes, while some states show growth rates of three to four per cent annually. Once again, Thuringia decreased in radiance.
The trend towards increasing night light emissions could be explained by a widespread change in outdoor lighting: LED lamps are replacing older technologies, and changing the ways in which light is used in both public and private lighting.
The researchers are still in the dark as to the reason why Thuringia shows a decreasing trend. In the study in IJSL which did not include the 2017 data, two other states appeared to decrease from 2012 to 2016: Saxony and Saxony-Anhalt. This trend, however, vanished after the team re-calculated the changes with the latest data from 2017.
Chris Kyba can only guess why Thuringia sticks out. "Maybe the data reflect the fact that older high pressure sodium lights are aging and decreasing in brightness," says Kyba. On the other hand, it could as well be that municipalities have already changed to LED lights, which appear darker to the satellite. The instrument that measured the changes, the Visible Infrared Imaging Radiometer Suite Day Night Band (DNB), detects light with wavelengths between 500 and 900 nanometers, corresponding to the colours green to red, and including invisible infrared.
White LED light includes a large component of blue light that the DNB instrument is not sensitive to. "So maybe Thuringia only looks darker simply because of the satellite's inability to see the blue light emitted from LEDs", says Kyba. He adds: "We definitely intend to follow up on this in the next years to understand the reasons behind lighting change in all of the states."
Original study: C. Kyba et al.: Changes in outdoor lighting in Germany from 2012-2016, in: International Journal of Sustainable Lighting IJSL (2017) http://www.
Josef Zens | EurekAlert!
Live from the ocean research vessel Atlantis
13.12.2018 | National Science Foundation
NSF-supported scientists present new research results on Earth's critical zone
13.12.2018 | National Science Foundation
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
Over the last decade, there has been much excitement about the discovery, recognised by the Nobel Prize in Physics only two years ago, that there are two types...
What if a sensor sensing a thing could be part of the thing itself? Rice University engineers believe they have a two-dimensional solution to do just that.
Rice engineers led by materials scientists Pulickel Ajayan and Jun Lou have developed a method to make atom-flat sensors that seamlessly integrate with devices...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
13.12.2018 | Life Sciences
13.12.2018 | Physics and Astronomy
13.12.2018 | Earth Sciences