New satellite observations reveal that changes in human behavior during holiday seasons — including bright Christmas light displays in the U.S. and a shift in activities during the holy month of Ramadan — are visible from space.
The study conducted by NASA and the National Oceanic and Atmospheric Administration
(NOAA), and co-led by Eleanor Stokes
, a Ph.D. candidate at the Yale School of Forestry & Environmental Studies, shows that light intensity increases by as much as 50 percent in some U.S. regions during the Christmas season.
In an analysis of light output from 70 cities during 2012 and 2013, they found that light intensity increased 30 to 50 percent between Thanksgiving and New Year’s Day in most suburbs and major city outskirts. Central urban areas were 20 to 30 percent brighter.
The researchers observed similar trends in Middle Eastern cities during the holy month of Ramadan, when people tend to push back social gatherings and meals until after daytime fasting. Those observations, however, varied from place to place depending on cultural and social dynamics of communities.
“The peaks that we observed are really ubiquitous and occur during the holidays,” said Stokes, a NASA Jenkins Graduate Fellow and Ph.D. candidate at F&ES. “[But] in the Middle East, we found a lot of variation between cities, with these lighting patterns tracking cultural variations.”
In some locations, including the Saudi Arabian cities of Riyadh and Jeddah, light usage increased by as much as 100 percent throughout the month. But in other regions there was little or no increase.