It's the time of the year when homes and business establishments turn up the lights for the holiday season and this distinct mark of people using more electricity than they normally would the rest of the year is evident even from space.
Data from the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite show the changes in the patterns of nighttime light during the year's major holidays. Suomi NPP, a collaborative mission of NASA and the National Oceanic and Atmospheric Administration (NOAA), carries VIIRS an instrument that can observe and detect the global glow of lights.
Using VIIRS data and an advanced algorithm that isolate airborne particles and moonlight clouds, scientists can see how and when people from across the globe light up the night. Miguel Román, who is part of the Suomi NPP Land Discipline Team, and colleagues first looked at the daily light output in 70 cities in the U.S. from 2012 to 2013 to see the patterns of energy use in urban areas.
The data revealed that night time lights in some parts of the U.S. shine up to 50 percent brighter during the country's major holiday, Christmas and New Year's, compared with their light output for the rest of the year.
The researcher's observations revealed that in the U.S., lights start to get brighter starting on Black Friday, the day after Thanksgiving marked by shopping frenzies, and this continues until New Year's day.
Most suburban areas and outskirts of major U.S. cities, where there are notably more yard spaces and single family homes as well as dark areas perfect for the holiday lights, increased their light intensity between 30 to 50 percent. Light intensities at the center of urban areas increased moderately by 20 to 30 percent.
The satellite data also showed that in some cities in the Middle East, nighttime light is more than 50 percent bright during in the month of Ramadan than the rest of the year. During this period, Muslims fast during the day so meals, social gathering and other transactions are pushed to nighttime.
The researchers said that the data does more than illustrate holiday light. These also show energy usage as well as cultural and social identities.
"By looking at the lights, we can see changes in human behavior," Roman said. "We can use that information to then understand what are the norms that are driving the decision behind energy."
