In 1967, the citizens of Earth were treated to a fantastical image: the first photograph ever showing Earth and its swirling white clouds with the moon in the same frame. This photograph, taken by NASA’s Application Technology Satellite I, was made possible through a collaboration with UW-Madison professor Verner E. Suomi, who became known as the “Father of Satellite Meteorology.”
Suomi’s research not only assisted NASA in taking these incredible photos, but it also acted as a springboard for NASA’s important role in climate science today. In the 1950s, Suomi led a project to measure the thermal energy levels of the entire earth from space for the first time. His measurements spearheaded the use of satellites to measure the energy flowing in and out of Earth to better understand our climate.
UW-Madison and NASA are about to add a new chapter in their decades-long collaborative efforts in climate science. In February, NASA announced its plan to fund the Polar Radiant Energy in the Far Infrared Experiment (PREFIRE) with Tristan L’Ecuyer, UW-Madison professor of atmospheric and oceanic sciences, as its principal investigator. Like Suomi, L’Ecuyer will also be using satellites to measure energy levels emitted by the earth, but for PREFIRE, he’ll be primarily collecting and analyzing data for the levels of infrared energy emitted by the Arctic.
“What we’re trying to do is use global observations — so observations from around the whole world which you can only obtain through satellites — to verify how well our climate models actually represent the climate. By improving how well we simulate today’s climate, hopefully we can predict the effects of human-induced climate change into the future a little bit more accurately.”
The Arctic’s importance lies in the role it plays as Earth’s “thermostat”, as L’Ecuyer describes it. The Arctic ice cap reflects sunlight and sends some of the energy arriving from the sun back into space. By reducing the amount of energy the earth absorbs and emitting thermal energy to space, the Arctic acts as our air conditioning unit.
However, the Arctic ice cap has been rapidly changing in recent years — its temperatures are rising four times faster than anywhere else on Earth, and its vast sea ice sheet is shrinking every year.
By measuring the infrared energy emitted by the Arctic ice sheet, L’Ecuyer hopes to provide data to help climate scientists better understand the Arctic’s role in climate change. “The amount of energy that the earth is emitting back to space to balance [the sun’s energy] is changing,” L’Ecuyer said. “We talk about it as a balance beam. On one side you have the sun’s energy coming in, and on other side you have the earth’s energy going out. If those are equal, the planet’s temperature stays the same… but if the sunlight exceeds the energy that the earth can emit, the Earth will heat up.”
About 60 percent of the Arctic’s thermal energy emissions have not been directly measured before due its difficulty to access by land or sea. Instead, PREFIRE will use CubeSats, small and inexpensive satellites that will carry instruments that can measure the variations of radiated energy from the Arctic.
“NASA has been the leader in the world in terms of developing new technologies to make [satellite] measurements capable and possible,” L’Ecuyer said. “These measurements would not have been possible even five years ago without the support of NASA to develop the CubeSat technology and figure out how to miniaturize the instruments so they can fit in these satellites.”
The PREFIRE CubeSats are tentatively scheduled to be launched at the end of 2021. In the meantime, the team will be working on manufacturing the satellites and the data collection software, and integrating the two together. L’Ecuyer is hopeful that PREFIRE will help climate scientists learn how the Arctic sea ice and the Greenland ice sheet is melting, and integrate the data into current and predictive climate models to better understand how the effectiveness of the Arctic’s thermostat is being reduced.
But there may be other surprises in store when PREFIRE starts collecting data — as L’Ecuyer says, “when you make a measurement for the very first time, there are unlimited possibilities for learning new things!”
