[music] Narrator:
When seen from the ground holiday lights give us cheer and help us celebrate the season.
But from space, over time, they can tell us something about both culture
and energy usage. Three years ago
a new satellite called Suomi NPP began to give us brilliant new views of the Earth
by day and by night. But as stunning as it is
to see Earth all aglow, this is still just one composite image
averaging observations over a period of months. Getting the
big picture from space is always helpful, but we can learn even more
seeing that picture change over time.
A NASA-lead team of researchers has been pouring over the data from NPP
and compensating for factors like the reflection of the moon and the effect
terrain, clouds, aerosols, to produce a scientifically-valuable
measuring Earth’s lights on a daily basis.
The first thing they noticed in the data was the effect of holidays.
Román:When we started looking at the data at night over the
we were expecting to see a lot of stability in the night time lights.
And we were really surprised to see this really vibrant increase
in activity during the holidays particularly around
areas in the suburbs.You have a lot of single-family homes
with a lot of yard space to put in lights.
Narrator:Comparing the six weeks between Thanksgiving and New Years to the rest of the year,
the team noticed large areas where night lights were 20, 30, even 50 percent
brighter over the holidays, as shown here in shades of green.
Román:And so what we are seeing is this shift in location
in activity where people are staying in their homes
and they’re celebrating, or they’re traveling to the rural areas
and they’re celebrating … and they’re turning on the lights
. Whereas in the urban centers people are turning off the lights because they’re going off for the holidays.
Narrator:
Researchers actually first saw changes in holiday lighting patterns during Ramadan in the Middle East.
Román:In contrast to the western holidays of Christmas and New Years, during Ramadan
you don’t see a shift in activity in location. What you’re seeing is that communities
are staying where they are, and they’re shifting their activities
to the nighttime.
Another thing that the … measurements are telling us is that it’s capturing cultural differences even
within a single community like the Muslim community
during the month of Ramadan. We’re seeing patterns in behavior
that varies significantly from country to country,
a smaller increase in nighttime lights in Turkey, large increase of nighttime lights in
Saudi Arabia, no increase in nighttime lights in Israel
because it’s not a predominantly Muslim country. So it’s a lot of diversity seen within the data.
Narrator:Because the night light data has such good resolution,
researchers from Yale University have even been looking at
neighborhoods within cities, and correlating that data with known political and
socio-economic factors.
But from a NASA perspective, why is it important to concentrate on Earth’s lights from space?
Román:A lot of our capability focuses on
using satellites to get a global picture of where we are
with respect to the environment and with respect to the day-to-day processes
processes that drives the earth system. A big component of that is
human activity and how they are driving the different processes
that impact the earth like carbon emissions and
like the heating patterns across cities.
So by looking at the lights we can see changes in human behavior
throughout the seasons, throughout the days, and we can use
that information to then understand what are the
norms that are driving the decisions behind
energy. If you look at climate change
research right now, we know that more than 70 percent of emissions
are happening in cities. So NASA is putting a lot of emphasis
on understanding cities and understanding the dynamics
dynamics of how cities are interacting with the climate and our system as a whole.
[music]