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At night, the NASA/NOAA Visible Infrared Imaging Radiometer Suite (VIIRS) collects visible wavelength low-light imaging data in a Day / Night Band (DNB). The DNB is designed for cloud imaging using moonlight (instead of sunlight) as the illumination source. The DNB also detects electric lighting and features like gas flares. The Earth Observation Group (EOG) generates monthly global cloud-free averages of the DNB radiance. This records spans April 2012 to the present – nearly seven years. It is possible to detect and track the spread and subsequent recovery of power grid collapses in conflict zones. A prime example of this is Syria, where large portions of the country lost electric power access in recent year. The expression of power outage in the VIIRS data is the loss or reduction in DNB radiances.
The image shows the VIIRS DNB radiances from April for three years as blue, green and red. The blue is April 2012, green is April 2015, and red is April 2018. The area where the lights have not been affected by the conflict show up as white in the lower left hand corner. Large portions of Northern Syria show up as blue, indicating lighting present in 2012 was absent in 2015 and 2018. There is a patchwork of hues in the nighttime lights of Turkey, an indication of electric power instability. There is a red linear feature in the lower right, inside of Iraq. This corresponds to settlements along the Euphrates River, which had power in 2018, but not in 2012 and 2015. There is also a narrow string of lights along Highway 10 running from Ramadi, Iraq west to Jordan.