Artificial light is a unique signature of human activity, with strong correlations to population, economic development level, and electrification rate. It is also a form of global change that remains poorly understood, with consequences for ecosystem services and loss of biodiversity. The spectral, spatial, and temporal patterns of artificial light emission of cities are examined. 

More details are available in our open access publication: http://www.mdpi.com/2072-4292/7/1/1