The Urban Social and Energy Use Data Embedded in Suomi-NPP VIIRS Nighttime Lights: Algorithm Overview and Status

Abstract:

Although urban areas contribute between 67-75% of global greenhouse gas (GHG) emissions, there is very little understanding of what drives anthropogenic emissions both locally and globally. Part of this gap in knowledge is due to a lack of reliable measurements across a range of urban scales. Where, when, and how much urban areas use energy is also a function of human activity patterns and social practices deeply embedded in culture. One apparent manifestation of energy use patterns in human settlements is in the celebration of holidays – when human activity patterns change, this affects short-term patterns in energy consumption. Using satellite-based retrievals of nighttime lighting (NTL) during three major holiday periods, (1) Christmas and New Year’s, (2) the Holy Month of Ramadan, and (3) the Chinese Spring Festival, we demonstrate that cultural variations within and between urban areas contextualize and shape the magnitude and timing of energy use. We derived NTL signatures from the Suomi-NPP satellite's (VIIRS) Day/Night Band for two years and over 1200 cities. The high-quality NTL retrievals are based on the latest science reprocessing (Collection V1.1, c. 8/2014) produced by the Land Product Evaluation and Analysis Tool Element (Land PEATE) at NASA’s Goddard Space Flight Center. After correcting for cloud and snow cover, as well as atmospheric-, terrain-, lunar BRDF-, fire-, and straylight effects, the high-resolution NTL time series were decomposed into seasonal, trend, and remainder signals—revealing strong, consistent patterns of activity changes during holiday periods. We demonstrate that patterns of holiday luminosity reveal changes in human activities important for understanding urban demographics and urban dynamics, and are strong examples of the socio-cultural and energy demand signatures embedded in satellite remote sensing imagery.