NASA’S FLYING LAB SEEKS TO UNDERSTAND ATMOSPHERE
The final leg of the four-part expedition of the ATom project will take off Friday from Palmdale
A suite of scientists are zigzagging across the globe in a flying laboratory, a DC-8 research plane retrofitted to gulp the air we breathe.
Soaring from the Arctic to Antarctica on flights crammed with valves, funnels and testing equipment, scientists from NASA Ames Research Center in Mountain View and other labs capture greenhouse gases and gather data about pollution in Earth’s atmosphere. The final leg of the four-part expedition of the Atmospheric Tomography Mission, also known as ATom, will take off Friday from Palmdale. Their mission: Give scientists important information about changes in the composition of gases in the atmosphere.
“We want to understand how much impact human beings have had on the remote parts of the atmosphere,” says the flight’s Principal Investigator Steven Wofsy, who is a professor of atmospheric and environmental science at Harvard University.
Currently, satellites monitor the skies hoping to get clues about changes in the atmosphere. But that’s simply not enough, according to the team. This satellite data only reveals the big picture.
The aircraft, he says, “is designed to provide information
“The only thing we avoid is nasty weather.”
— Michael Prather, UC Irvine professor
that allows you to understand the details that lie behind the big picture.”
Earth’s atmosphere is chiefly composed of nitrogen, at around 78 percent. Oxygen, which makes up about 21 percent of the atmosphere, is followed by argon, which can be found in light bulbs, at .9 percent. The last 2 percent of the atmosphere is composed of other trace gases — or atmospheric leftovers — like carbon dioxide, methane, helium, neon, nitrous oxides and ozone.
The researchers are particularly focused on the role of carbon dioxide, methane, and ozone. Even though they represent a small amount of the gases in the atmosphere, they play a big role in shaping Earth’s climate because of their potency. The build-up of these gases in the atmosphere creates a blanketlike layer of gases that trap heat and damage ecosystems around the world.
Valves attached to the outside of the plane slurp up these chemicals and funnel them to equipment on board. These instruments come from labs at Harvard, University of Colorado Boulder, and CalTech, and are specifically designed to detect how different gases and particles in the atmosphere interact with each other. They’re also searching for pockets of atmosphere that contain higher amounts of air pollution. By mapping these pollutants, scientists can try to identify where they are coming from.
Atmospheric Tomography Mission project manager Dave Jordan, of NASA Ames Research Center, says that a project like this — an attempt to create a global atmospheric chemical database — has never been attempted.
In order to collect samples from a broad range of atmospheric conditions, the pilots make elevation sweeps where they gently drop the plane to 500 feet and then slowly climb back up to a cruising altitude of up to 40,000 feet.
“The only thing we avoid is nasty weather,” says UC Irvine professor Michael Prather, who is deputy principal investigator of the mission.
NASA Ames Engineer Paul Bui’s instrument, which measures wind direction, requires the plane to dive, swerve, and tack sharply in order to get the most accurate readings. Not everyone is accustomed to these dramatic maneuvers, and some people suffer from motion sickness.
Then there’s the temperature. To prevent the instruments from overheating, the temperature inside the plane is nearly as cold as it is outside the plane.
“Literally, I was just freezing all the time,” Bui says. “I had full ski gear on.”
In the back of the plane, tucked away near the arctic survival gear, a small galley is equipped with the essentials — a microwave and a coffeemaker.
When they weren’t nuking ramen noodles, the team enjoyed pear empanadas from a local purveyor in Punta Arenas, Chile, who has served every deployment that’s swung through town. They indulged in fresh seafood in Terceira, a Portuguese island in the Azores, and feasted on foot-long lobsters in Bangor, Maine.
Some pockets of the atmosphere above the planet store surprising amounts of pollution.
The air over Ascension Island, a small British territory halfway between South America and Africa, is one of those places. By analyzing the chemicals collected on the Summer 2016 mission, the team was able to identify the pollutants and particulates in the air and link them to a spate of wildfires in Central Africa. They also discovered distinguishing markers for chemicals emitted from North Africa’s petrochemical industries. Landing on the smog enveloped island was evidence enough.
“If you’re flying over Los Angeles, on a bad day, you can still see the surface,” says Wofsy. “We couldn’t see the surface.”
Prather says “there’s a lot of work done near the polluted regions, like cities, but polluted regions are actually a very small portion of the globe.” And the pollution that we often associate with big cities like Beijing, Los Angeles, and Dehli isn’t limited to those metropolitan areas. Remote parts of the atmosphere over the Pacific, Atlantic, and Arctic regions, trap large amounts of pollutants too.
“If I go to remote parts of the world, I should find an atmosphere that could be called pristine,”’ says Wofsy. “Unfortunately, that’s not true.”
Wofsy describes the Arctic, in particular, as “the perfect container for storing pollution.” The freezing temperatures and weather patterns tend to trap pollutants near the North Pole. Quantitative data from the flights showed that the amount and extent of the pollution in the Arctic was high.
Researchers are currently crunching numbers from October’s flight, which will be released in June. The data from the first deployment in the Summer of 2016 is already available online, and scientists discussed their findings from the Winter 2017 deployment at January’s American Meteorological Society meeting.
With data in hand, researchers like Wofsy look to the future. He hopes that 20 years from now, scientists can use the findings collected during the ATom Mission to understand how the atmosphere has changed. But first, there’s more work to be done.
“We have one more season,” says Bui. “Then we have to sit down and look at the big picture.”