From Boing Boing:
You might recall an image release in 2012 of the Earth’s lights at night. Called Black Marble, the popular image was generated as a composite image from the best images by the taken over several months by NASA’s Suomi-NPP Visual Infrared Imaging Radiometer Suite (VIIRS). The instrument, according to NASA’s website, “detects light in a range of wavelengths from green to near-infrared and uses “smart” light sensors to observe dim signals such as city lights, auroras, wildfires, and reflected moonlight.”
Black Marble is a pretty image. It shows the light emitted by people, but it doesn’t give us a sense of how or why we are using it. So, Miguel Roman and Eleanor Stokes set about creating a dynamic understanding of human behavior at night around the globe.
They took over 3 years of Suomi-NPP VIIRS data over major urban areas in North America, the Caribbean, and the Middle East, and developed algorithms to get rid of view-obstructing clouds, correct terrain errors, correct for atmospheric effects, and to remove light contamination from the moon, fire, and stray light. Overall, they focused on daily changes in lighting at the country, city, and neighborhood scales during the holiday season as compared to the rest of the year.
The result is visually dramatic. During the holidays our activity patterns change. This in turn changes the location of demand for energy services. For instance, in big metropolitan areas, lighting increases in predominantly suburban, residential areas. This is likely because people are leaving work earlier and going home to turn on lights. Also, McMansions require more light to illuminate with festive holiday lights. Interestingly, urban centers increase only slightly when compared to the suburbs, which is probably related to the fact that urban areas are more illuminated at night generally.