The Permafrost Tunnel provides a look back in time, allowing for research into the frozen ground of interior Alaska. Credit: NASA/Kate Ramsayer
by Kate Ramsayer / FAIRBANKS, ALASKA /
“What we’re going to do is walk back in time,” said Matthew Sturm, standing in front of a doorway that led into a hillside north of Fairbanks, Alaska.
Through the doors was a tunnel that provides access to the Alaska of 40,000 years ago, when bison and mammoths foraged in grassy valleys. Now, however, the grasses and the animal bones are frozen in the ground in the Permafrost Tunnel.
The tunnel, run by the U.S. Army’s Cold Regions Research and Engineering Laboratory, was dug in the 1960s and is the site of much research into permafrost—ground that stays frozen throughout the year, for multiple years. Sturm, a professor and snow researcher at the University of Alaska, recently led a group with NASA’s Arctic Boreal Vulnerability Experiment (ABoVE) to the site. The walls of the tunnel expose the silt, ice, and carbon-rich plant and animal matter that has been frozen for tens of thousands of years.
“It’s a legacy of the Ice Age,” Sturm said. Roots of long-buried grasses hang from the ceiling, in a few places bones of Pleistocene mammals are embedded in the wall.
Matthew Sturm points to some grasses and sticks that were buried during the Ice Age and frozen in the ground and now exposed in the ceiling of the permafrost tunnel. Credit: NASA/Kate Ramsayer
What will happen to the carbon contained in permafrost in the Alaska interior and elsewhere in the northern latitudes is a major question for NASA’s ABoVE campaign, which is studying the impacts of climate change on Alaska and northwestern Canada. Temperatures are rising in the Arctic region, which means permafrost is thawing at faster rates—and when it thaws, it releases carbon dioxide or methane into the atmosphere.
One ABoVE project is taking steps to monitor the temperatures of the permafrost across Alaska to see how far below the surface it is frozen and whether the temperatures of the soil layers are changing.
“We’ll get temperature data across large territories to supplement the existing data,” said Dmitry Nicolsky, with the University of Alaska, Fairbanks. Most of the existing data is along easy-to-access roads—but there aren’t many roads in Alaska. Nicolsky and his colleagues are working with researchers at USArray, which is establishing earthquake-monitoring stations across the state. Those crews are also drilling about 20 boreholes for thermometers this year, with more planned.
Dmitry Nicolsky demonstrates how sensors are inserted into a borehole to measure the temperatures of layers of soil and permafrost at different depths. Credit: NASA/Kate Ramsayer
Nicolsky has been getting the instruments ready for deployment. Crews will install lines that have six temperature sensors at six different depths, from just below the top mossy layer to more than 6.5 feet below the surface. They’ll take readings several times a day for three to five years to help the scientists get a more complete picture of how temperatures in Arctic soil are changing.
On August 3, NASA’s DC-8 flying laboratory prepared for takeoff from Anchorage, Alaska en route to Hawaii as part of the Atmospheric Tomography (ATom) mission’s global survey of the atmosphere. Credit: Roisin Commane
by Samson Reiny
It was a week of eclectic locales last week for the Atmospheric Tomography, or ATom, mission. On Monday, August 1, NASA’s DC-8 flying laboratory took off from the high desert of NASA’s Armstrong Flight Research Center in Palmdale, Calif., and made its way to near the North Pole before touching down in Anchorage, Alaska. Two days later, the team left the cool, crisp air for balmy Hawaii, laying over for a few days in Kona, on Hawaii Island.
All the while, in flight the 23 instruments on board measured and collected air samples from a range of altitudes as part of the mission to survey the world’s atmosphere.
Upon liftoff from Palmdale, the team caught glimpses of two defining features of the summer Southern California air: haze from smog stemming from the Los Angeles Basin, and smoke and ash from a wildfire, this one from the tail end of a large blaze that charred about 65 square miles (39,000 acres) in the mountains near Santa Clarita Valley.
“More frequent wildfires in this area are expected because of climate warming,” said ATom principal investigator Steve Wofsy, noting that drier landscapes and higher temperatures up the odds of igniting a blaze.
The crew also sighted wildfires in areas near Pyramid Lake, in northwest Nevada, that had been started by dry lightning strikes a few days prior.
The ATom team flew over a streak of wildfires near Pyramid Lake in northwest Nevada. Credit: NASA/Paul Newman
But eventually the air cleared as the DC-8 soared over the dramatic vistas of the northwest United States before continuing on to the Arctic, which Wofsy called “the heartland” for climate change.
“The Arctic is changing very, very quickly, and we wanted to see how it’s changing both in terms of its climate and its atmospheric chemistry,” he said. The Arctic is warming faster than the rest of Earth. Temperatures in the region are now 2.3 degrees Fahrenheit above the long-term average, the highest since modern records began in 1900.
ATom scientist Roisin Commane of Harvard University noticed one of the most visible markers of that warming—the skinniness of the first-year sea ice compared to years past. “Even way up at 78 degrees north latitude, the sea ice was really, really thin,” she noted. “Twenty years ago, there would have been thick and lumpy sea ice all over.”
The ATom team flew over the Arctic Circle to collect measurements of the atmosphere for the ATom mission. Credit: NASA/Paul Newman
Another observation taken from instruments were heightened amounts of sulfur aerosols. “Normally the sea ice would keep a lot of the chemical compounds sealed in,” Commane said, “but with so much broken ice, everything can make its way out pretty easily.”
“Aerosols often have a cooling effect on the climate because they scatter sunlight and make clouds whiter and last longer,” added Christina Williamson, a post-doctoral scientist at the Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder. “In the Arctic this may not happen because snow and ice are already highly reflective, but with less and less sea ice, they could become more important.”
At high altitudes, the team picked up gases indicative of biomass burning, which scientists on board suspect came from recent wildfires in Siberia. Wherever they came from, the gases originated very far away since they were picked up in a remote area of the Arctic.
A view of the Kona coast, on Hawaii Island, before the ATom crew touched down on August 3. Credit: Roisin Commane
In fact, many gases are world travelers. On Wednesday, August 3, on the way to Kona, the DC-8 flew through a highly polluted layer of atmosphere a couple hundred miles north of the Hawaiian islands. It likely came from Asia, says Paul Newman, Chief Scientist for Earth sciences at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, and co-leader of the ATom science team. “The pollution was probably lifted to higher altitudes by convection in Asia, and then carried over the Pacific by the normal westerly winds.”
This around-the-world trip has only just begun, but it’s already proving to be interesting. “It’s exciting just seeing what comes in,” Commane says. “We’re never sure what to expect.”
It’s the morning meeting before the day’s flight on Thursday, Aug. 4. Fingers are clacking away at laptop keyboards. Starburst and Jolly Ranchers are scattered across a long table.
Almost as colorful as the candy are the weather maps projected onto the wall. They show a weather front slicing clean through Nebraska. Storms are likely later in the day. We’ll soon be chasing carbon dioxide and methane around both sides of the front in NASA’s C-130 Hercules research aircraft.
Fields of green are an ever-present sight on the August 4 science flight, which nips down into Missouri before heading back up through Nebraska and into southern South Dakota. Credit: NASA/Joe AtkinsonDan Lahrman, an electrical test engineer, pours liquid nitrogen into the Multi-function Laser Lidar before takeoff. Instrument technicians have to keep a detector in the lidar as close to absolute zero as possible. During long flights, that sometimes means waiting for a smooth stretch and refilling the liquid nitrogen in the air. Credit: NASA/Joe Atkinson
The flight is part of the Atmospheric Carbon and Transport–America, or ACT-America, campaign, which is investigating how weather systems and other atmospheric phenomena affect the movement of the two greenhouse gases in the atmosphere.
Our flight path will take us into the northwest corner of Missouri then back north through Nebraska and into South Dakota.
“We’re going after something that should be dominated by transport,” says Ken Davis, principal investigator for ACT-America from Penn State.
Looking at flight scenarios for upcoming days, ACT-America instrument scientist Josh DiGangi of NASA’s Langley Research Center in Hampton, Virginia, suggests an ambitious path that involves a spiral pattern.
“Oh, that just makes my head hurt,” Davis says.
The C-130 sits on the tarmac before takeoff. Credit: NASA/Joe AtkinsonPilots Brian Bernth, foreground, and Jeff Callaghan maneuver the C-130 to altitudes from 1,000 to 25,000 feet. Twice during the 5-hour flight, they push the aircraft into long, looping spirals that start high and end with turbulent low-altitude runs. Credit: NASA/Joe Atkinson
In the minutes before everyone heads out to the aircraft, a reporter from the Lincoln Journal Star calls. He’s hoping to find out what NASA is doing in Lincoln.
It’s a fair question. Amid the hubbub of people prepping for the flight, Davis explains to the reporter that the Midwest is a region ripe with greenhouse gas fluxes, or areas where lots of greenhouse gases are exchanged between the biosphere on land and the atmosphere.
Agriculture is a huge factor. The vast, seemingly endless fields of corn and soybean in the area gobble up a lot of carbon dioxide. Cows and other livestock produce copious amounts of methane. Coal operations in Wyoming, and oil and gas production in the Dakotas contribute to the complex atmospheric chemistry as well.
“It’s the kind of ecosystem we want to understand,” Davis tells the reporter.
Weather plays a factor, too. Big storms churn up the gases and move them around.
“This is where the storms form,” Davis says. “Many mid-latitude cyclones are born on the eastern slope of the Rockies.”
Ken Davis, ACT-America principal investigator, stays glued to his laptop monitoring data through much of the flight, though he occasionally pokes his head up into the cockpit to snap photos. Credit: NASA/Joe AtkinsonRebecca Pauly of NASA’s Goddard Space Flight Center preps the Cloud Physics Lidar before takeoff. Credit: NASA/Joe AtkinsoJosh DiGangi, ACT-America instrument scientist from NASA Langley, monitors in situ greenhouse gas measurements in real time during the flight. Credit: NASA/Joe Atkinson
On the C-130, not long after takeoff, Davis climbs the stairs into the cockpit.
“After we get to the end of this,” he says, gesturing out at the clouds, “we’re going to spiral down, turn around and fly at about 1,000 feet.” He moves his hands up and down to simulate turbulence. “That’s usually pretty fun.”
And it is. The first time. Another bouncy low-altitude run later in the flight puts my inner ear to the test.
Other than that, though, it’s a relatively smooth, comfortable ride — even with a fair number of altitude changes. Those changes are important. They allow the science instruments to gather data in different layers of the atmosphere.
Also, as Josh DiGangi puts it: “Remote sensing instruments like to be up high; in situ instruments like to be down low.”
In fact, the remote sensing lidar instruments can be dangerous at lower altitudes. A zap from one of the lasers could do real damage to the eyes of someone looking up through a pair of binoculars. That’s why lidar instruments have to be turned off at altitudes below 6,000 feet.
As he watches real-time data from his in situ instruments scroll across a computer monitor, DiGangi occasionally reaches into a nearby storage bin and pulls out handfuls of pretzels or cheddar popcorn. He offers to share.
“But don’t eat my banana,” he says. “That’s my banana.”
He’s joking. Sort of. But snacks and drinks are relatively easy to come by on the aircraft, anyway. There’s a microwave, a little refrigerator and even a coffee maker.
Little amenities like a coffeemaker make long flights more bearable. Credit: NASA/Joe Atkinson
After five mostly nausea-free hours in the air, the C-130 lands back in Lincoln.
“[Lincoln’s] not as exciting as traveling to some exotic part of the world,” Davis joked to the newspaper reporter that morning.
He’s right. It’s not exotic. But following a vicious thunderstorm that rips through Lincoln a couple of hours after the flight touches down, a vivid double rainbow arcs over the airport. It’s visible from end to end. Yeah, it’s not tropical beaches and palm trees, but it’s a beautiful sight nonetheless.
One of the main reasons for ACT-America coming to Lincoln is agriculture. The vast cornfields are major carbon sinks, and there’s no escaping them, not even at the airport. Credit: NASA/Joe Atkinson
Flying airborne science missions requires skill, patience and adaptability.
The C-130H pilots flying now over the eastern United States measuring carbon dioxide and methane for NASA’s ACT-America field campaign are asked to fly precise routes, giving scientists an opportunity to gather very specific sets of data on sources, absorption and movement of these gases.
In the skies over Maryland on July 22, pilot Jim Lawson takes in the view during an ACT-America flight to measure atmospheric gases. Credit: NASA/Sam McDonald
Readings taken by instruments aboard the aircraft will be compared to those collected on the ground, aboard a second ACT-America aircraft, and from a satellite on orbit. Making apples-to-apples comparisons means following exact flight profiles while shepherding the airplane through weather that’s not always sunny and mild.
Pilot Jim Lawson draws on 28 years of flying as a Navy pilot and a civilian flight instructor, putting in more than 10,000 hours at the controls of 11 different types of aircraft. Last year, he flew more than 30 times for NASA’s Operation IceBridge.
Jeff Callaghan has made the C-130 his specialty. He’s been piloting that type of aircraft since getting his wings as a Marine in 1995. He has accumulated more than 3,000 hours in the C-130. In May, Callaghan flew as part of NASA’s North Atlantic Aerosols and Marine Ecosystems Study.
Penn State’s Ken Davis (left), principal investigator for ACT-America, collaborates with C-130H pilots Jeff Callaghan (center) and Jim Lawson during a pre-flight huddle at NASA’s Wallops Flight Facility. Credit: NASA/Sam McDonald
We asked Lawson and Callaghan questions about what it’s like to fly American skies in the name of science and in support of ACT-America.
What do you find the most difficult or rewarding about flying for ACT-America?
Jim Lawson: Flying for science is very challenging and interesting. We are challenged as pilots when flying NASA mission profiles and get to use the full extent of our pilot skills. The reward is knowing that the work I do benefits the advancement of science and humanity.
Flying weather-dependent missions requires flexibility. When you find you can’t fly because of adverse conditions, how do you spend your time?
JL: While on the ground, the pilots are assisting the science team in the planning of the next missions. If one flight mission cancels for any reason, we look for ways to incorporate that mission into future mission profiles. Adaptability and flexibility are key!
You previously flew for the Navy and are currently in the Naval reserves. Was it hard to make the transition to NASA missions?
JL: All of the aircrew have prior military service. We have Navy, Marines and Air Force represented on the crew. The culture and work ethic are the same and we all work well together to get the mission done. The only difference is the mission and the customer. Unlike the military, where our mission would be to support combat operations and where the customer is the Department of Defense, the mission for us now is the NASA science objectives and our customer is our NASA science team.
Communication is key to achieve the NASA mission objectives, and this can be a challenge sometimes, but since we are all professionals, we learn to speak each other’s language. The aircrew become wise in the ways of science and the scientists learn the ways of aviation.
What do you like most about being a pilot?
JL: My office always has the best view.
At NASA’s Wallops Flight Facility, pilot Jim Lawson in front of the C-130H. Credit: NASA/Sam McDonald
Does flying along weather fronts present any unusual challenges?
Jeff Callaghan: Having flown the C-130 for so many years in all kinds of weather conditions, I would say that the only unusual thing would be trying to figure out where the front is, but that is why the science team comes up with our flight paths.
Do you feel like, as a pilot on this mission, you are playing a part in helping mankind better understand the planet?
JC: In some small way, yes. A lot of people can do what I do, but there are not nearly as many people who can do what the science team does.
What do you enjoy most about being a pilot?
JC: It is hard to describe. I just love flying. I especially love flying the C-130 and working closely with my crew.
Pilot Jeff Callaghan at NASA’s Wallops Flight Facility. Credit: NASA/Sam McDonald
by Samson Reiny / OVER THE EQUATORIAL PACIFIC OCEAN /
Feeling breakfast move toward my chest is the uneasy cue that NASA’s DC-8 flying laboratory is dropping altitude. We drop all right, from 35,000 feet to just 500 feet above the open ocean — the water so close the airplane’s wing starts to look like a diving board.
For the ATom mission, NASA’s DC-8 flying laboratory flies from 35,000 feet to 500 feet so that the instruments can measure and collect air samples throughout the atmosphere. Credit: NASA/Samson Reiny
Suddenly, the plane climbs hard, zooming toward the clouds. Standing, my feet are glued to the floor, the rest of my body wanting to follow. I’m dizzy, but I eventually adjust as we ascend to higher elevation.
That is, until we dive again. Seven more times, to be exact.
“I’ve never had such a nice flight,” says Donald Blake, smirking. An atmospheric scientist at the University of California, Irvine, he has flown on the DC-8 countless times over the years. “One of my students threw up 19 times during a really bad flight over Central California. I told him, ‘You’re never flying on this thing again.’ Well, I barely managed not to throw up myself.”
Donald Blake and Barbara Barletta, atmospheric scientists at the University of California, Irvine, spend much of the flight filling cans with air samples for later analysis. Credit: NASA/Samson Reiny
But in retrospect motion sickness is a small price to pay to accomplish the Atmospheric Tomography (ATom) mission’s ambitious objective: to survey the atmosphere around the world at a range of altitudes (hence the dramatic dips and ascents). The 23 instruments on board are tasked with measuring all together more than 200 gases and airborne particles in the most remote regions on Earth in order to help advance a number of scientific investigations.
On Friday, July 29, I joined 30 researchers on their first science flight: a nine-hour trek from NASA’s Armstrong Flight Research Center in Palmdale, Calif., to the equator in the Pacific Ocean and back. Next up would be a 23-day whirlwind trip, with far-flung stopovers in American Samoa in the Pacific, Ascension Island in the middle of the Atlantic, and Kangerlussuaq, Greenland, in the Arctic Circle, among others.
What is clear about being on a science flight is that instruments are the first-class passengers. These costly, often oven-sized machines are checked incessantly, the thermostat set to their liking, their bodies secured for the vicissitudes of flight. From the onset, they cause a ruckus, some more than others. At one point, a distressed passenger snatches my front row seat while I’m away. She points first to her ears then to the back of the plane. I hear a high-pitched warble that becomes more shrill the closer I move toward it.
Space can be tight on board the DC-8 during an ATom flight. Credit: NASA/Samson Reiny
“I should have told her the instrument behind me gets particularly loud,” says a regretful Roisin Commane, an Irish-born Harvard University scientist who’s assisting with the Quantum Cascade Laser, or QCLS, which uses light absorption to measure levels of carbon dioxide, methane, carbon monoxide, and nitrous oxide.
If all is well, Roisin’s instrument pretty much runs on its own, making her one of the lucky ones. Others are married to theirs. University of New Hampshire scientist Jack Dibb, a gruff, ponytailed man, is always on his feet changing out filters for his Soluble Acidic Gases and Aerosols, or SAGA, instrument as it passes through a string of altitudes and latitudes. The filters will be brought back to a lab and analyzed for pollutants such as nitric acid and for aerosols that are signatures of biomass burning, which includes wildfires.
University of New Hampshire scientist Jack Dibb is on his feet for much of the flight replacing filters for his Soluble Acidic Gases and Aerosols instrument. The filters will be brought back to a lab and analyzed for pollutants such as nitric acid and for aerosols that are signatures of biomass burning. Credit: NASA/Samson Reiny
Donald Blake, the veteran DC-8 traveler, usually has his hands full fussing with the valves of his Whole Air Sampling machine, capturing air samples in cans to be sent to his and others’ labs for analysis of a hundred different gases and particles. Today fellow UC Irvine researcher Barbara Barletta is helping out. The duo eventually fills 166 cans.
Some instruments even require their own maneuvers. The Meteorological Measurement System records in situ pressure, wind and temperature data. To establish a reference point for the wind measurements, the DC-8 pilots conduct a few maneuvers, namely the “pitch” (quick up-and-down movements), the “yaw” (moving side to side like a crab), and the “box” (a succession of tight turns that result in a box pattern when seen from above).
Even in the cockpit, the safest spot for a sensitive stomach, these maneuvers make me squirm. “Nobody likes that guy,” Blake later says jokingly of the instrument’s scientist.
Throughout it all, many researchers are hunched over computers, transfixed by the incoming data displayed through colorful graphs and charts. Over the intercom, they share results, talking in science jargon, and communicate with the navigator and the mission director and assistant mission director, who negotiate the science team’s needs with the pilots.
NOAA’s Tom Ryerson is glued to his computer screen for much of the flight, watching data stream in from his Nitrogen Oxides and Ozone instrument. Credit: NASA/Samson Reiny
As we near the equator, when I hear Tom Ryerson, who leads a research group in the National Oceanographic and Atmospheric Administration’s Chemical Sciences Division, exclaim over the intercom, “This is lowest NOy [total reactive nitrogen] measurement I’ve ever seen, 70 ppt [parts per trillion],” I take notice.
NOy, Ryerson explains, is the sum of all nitrogen oxides, which derive from pollutants emitted from power plants, cars and trucks, and forest fires. His Nitrogen Oxides and Ozone instrument is delivering that measurement in real time. Levels of NOy are usually lower near the southern hemisphere, far away from their sources, but not this low, he says. “This was really low—about 10 times lower than in the northern hemispheric air we just sampled on our way south from Palmdale.”
NOy measurements taken during the rest of the mission will be useful for testing global models that simulate sources of NOy on the continents and how they’re mixed around between the northern and southern hemispheres and also how they’re scrubbed by clouds.
“The key thing about ATom is that we’re making these measurements in very under-measured parts of the world where the global models have very few measurements to compare against,” Ryerson says. “We’ll measure some things in some parts of the world that really haven’t been observed before.”
Moments later, he informs me that a few of the instruments picked up dust particles the team think came from Africa. Their sizes are much larger than expected and may indicate something new about how far dust can travel after being picked up by windstorms in the world’s deserts.
“Not bad at all for a first flight,” Ryerson says. “It feels like the start of a concert. The instruments are warming up, right before the symphony starts. There’s lots of anticipation of great stuff to come.”
Gathering data on atmospheric carbon dioxide and methane in the skies over the U.S. East Coast can be intense.
ACT-America researchers running instruments such as the Multi-functional Fiber Laser Lidar (MFLL) and ASCENDS CarbonHawk Experiment Simulator (ACES) are generally all business as they monitor their expensive technologies built to measure greenhouse gases.
Penn State meteorology professor Ken Davis views conditions from the cockpit of the C-130H during the ACT-America flight on July 22. Credit: NASA/Sam McDonaldAboard the C-130H, Nathan Blume (standing) and Jeremy Dobler monitor data from an instrument that uses laser light to measure atmospheric carbon dioxide. Credit: NASA/Sam McDonald
They stare intently at computer readouts telling them how instruments are functioning. They note subtle changes as their machines gather readings that will help show where carbon dioxide and methane come from and how those gases move through the air.
It’s serious work, but that doesn’t mean researchers can’t take a moment to savor the day’s accomplishments.
As soon as pilot Jim Lawson turned the C-130H homeward on July 22 after some four hours of methodical zigzagging above Maryland, Virginia, West Virginia and Pennsylvania, Yonghoon Choi decided it was time for a break.
Choi, who was in charge of the flight’s in situ (meaning “in place”) measurements, reached into a bin beside a tall rack of readouts and electronics and pulled out something tasty.
He produced a plastic bag laden with chocolate morsels, fruit chews and hard candy. Then, he hopped up from his seat and walked through the hold of the C-130H, offering his teammates something sweet.
Yonghoon Choi from NASA’s Langley Research Center prepares to share treats with his fellow researchers during the July 22 ACT-America science flight. Credit: NASA/Sam McDonald
“It’s our tradition,” Choi said, based at NASA’s Langley Research Center in Virginia. “When we’re going home, we eat candy.”
Choi is a veteran of more than a dozen airborne science campaigns like ACT-America. He’s been taking in situ measurements for some 15 years and has flown on aircraft including the DC-8, DC-12, the P-3, the Falcon and the P-20.
He explained that it’s not unusual for science flights to stretch to 8-10 hours. “After that long, everybody’s tired and ready for a treat,” Choi said, smiling.
On this flight, the ACT-America team encountered mostly clear summertime weather as they flew alternating legs at 1,000 and 10,000 feet. But there were moments of bumping and bouncing. Choi and ACT-America Principal Investigator Ken Davis stayed in close contact as the C-130H crossed in and out of what atmospheric scientists call the boundary layer.
The cargo bay of the C-130H outfitted with instruments that measure atmospheric gases both directly and remotely using lasers. Credit: NASA/Sam McDonald
“That was complicated today,” Davis said to Choi as the aircraft flew back toward its home base at NASA’s Wallops Flight Facility in Maryland. There was convection in the lower atmosphere and fluctuations in the boundary layer, the region of the lower troposphere where proximity to Earth’s surface creates turbulent air.
An irregular boundary layer can make measurements more difficult to parse.
“The data collection was fine, everything was working,” said Davis, a professor at Penn State University. “What we collected represents a relatively complicated state of the atmosphere.” Sources and sinks of greenhouse gasses are in action along with forces that transport them through the air.
“It’s challenging to interpret, but it doesn’t mean it can’t be interpreted,” Davis said. “The world is complicated some days.”
This NASA airborne science experiment that started flights over the eastern United States this month resembles a classic case of “who done it?” ACT-America, the Atmospheric Carbon and Transport – America expedition, is studying the movement of two powerful greenhouse gases — carbon dioxide and methane.
It was hot and humid in the Mid-Atlantic region as the first set of science flights began in mid-July. The scene on July 18 was the hangar at NASA’s Langley Research Center in Hampton, Va. The lineup of potential suspects included gases from plants, fossil fuels, air conditioning units and electrical transformers.
Technician Jim Plant gets the ACT-America science instruments ready onboard NASA’s B-200 aircraft.
Inlets built into several sensors on the belly of NASA’s B-200 aircraft take in samples of the air and atmospheric gas with the push of a button once the flight was underway. The sensors are strategically placed to not take in any exhaust from the aircraft.
Inlets on the belly of the NASA B-200 collect samples of carbon and methane during flight.
For ACT-America’s first B-200 science flight, Colm Sweeney from the National Oceanic and Atmospheric Administration (NOAA) at Colorado State University watched from the hangar as the B-200 prepared for takeoff with NOAA’s flask package onboard. Air samples that fill the flasks are atmospheric fingerprints that provide clues about where individual chemical compounds came from.
“Plants take up lighter carbon, and emitted carbon has a different ratio,” Sweeney explained.
Gases have certain tracers, such as SF6 used in electrical transformers, and those tracers stay with them as they rise into the atmosphere as a plume.
“We’re basically getting a fingerprint on where the plumes are coming from,” Sweeney said.
Jim Plant was the lone instrument operator aboard the aircraft, accompanied by science instruments, a pilot and co-pilot to minimize the weight on board for a longer duration flight. The B-200 met up in a predetermined area or “box” along with the larger, more instrumented NASA C-130 aircraft that took off from NASA’s Wallops Flight Facility along the Virginia coast.
The B-200 meets up with the C-130 aircraft in coordinated flights over the Mid-Atlantic region this month.
The B-200 made lawnmower patterns inside the box and circled down through layers of the Mid-Atlantic atmosphere to study how carbon dioxide and methane cycle into and out of the atmosphere.
“We want to better understand what’s going on inside the box to later extrapolate what’s going on outside of the box,” said Byron Meadows, ACT-America’s aircraft instrument manager.
With the push of a button onboard, a sample of air and gas fills the flask package, which is closed off from outside exposure. Once the dozen flasks are filled, the monitor reads, “Have a nice day.”
ACT-America team members discuss final preparations before the start of the Mid-Atlantic portion of the month-long flight campaign.
After the flights, the samples are sent back to a lab at Colorado State University where they are analyzed. The final step, according to Sweeney, is to model the samples to determine if carbon and methane emissions are increasing or decreasing.
“If we plan to curb emissions, we have to be able to check the accuracy of them and inform the proper policies needed to make a difference,” Sweeney said.
In addition to the flask system that collects samples from the air, several other instruments are integrated into the B-200 to study carbon and methane. Several ground measurement sites complement and fill in gaps between the study regions
This case is far from closed. In August ACT-America continues its sky sleuthing over two other parts of the eastern U.S. with flights from Lincoln, Nebraska, and Shreveport, Louisiana. With each passing flight, the data collected provides scientists with new clues that will help improve diagnoses of the global carbon cycle for decades to come.
Taking off from the Wiley Post-Will Rogers Memorial Airport provides a view of Barrow and the neighboring Chukchi Sea, at 71° N latitude. Credit: NASA/Kate Ramsayer
by Kate Ramsayer / BARROW, ALASKA /
A cloudy day in the middle of Operation IceBridge’s summer campaign in Barrow, Alaska, meant no flights that day, so instead several members of the campaign showed local kids how to build and fly NASA-quality paper airplanes.
“This is what an engineer does, see what works and what doesn’t,” pilot Rick Yasky told one elementary-age summer camper.
Pilot Taylor Thorson, of NASA’s Langley Research Center in Virginia, shows Barrow kids how to design different kinds of paper airplanes. “There’s no right or wrong way to do it, we’ll just try to make it fly” he said. Credit: NASA/Kate Ramsayer
The campaign, which measured melting sea ice in the Arctic, was the first IceBridge mission out of Barrow, so while in town the 11 scientists, pilots and flight crew explored the local science, culture and community.
One of the flight crew was walking along the beach when he came across fishermen pulling in a line of salmon—he helped, and walked back to the hotel with enough fish to eat for the rest of the campaign. Another chatted with local women who were removing reindeer tendons, which would dry out until the fall when the women would braid them together to use in sewing.
And in the middle of the campaign, they helped at a summer camp by making birdhouses, holding a paper airplane contest and showing the campers the NASA Falcon jet out of Langley Research Center in Virginia.
John Woods, Operation IceBridge project manager with NASA’s Goddard Space Flight Center in Greenbelt, Maryland, explains the rules of a paper airplane contest to day campers at a Barrow summer program. There were two categories: farthest distance and longest aloft. Credit: NASA/Kate RamsayerBarrow day campers check out NASA’s Falcon jet, which IceBridge flew for its summer sea ice campaign. Credit: NASA/Kate Ramsayer
“When anyone comes up, we like to have them visit with the kids,” said Chris Battle, Barrow recreation director and deputy mayor. “We’re isolated so it’s good to let them have exposure to these things.”
John Woods, IceBridge project manager, also gave a library talk on how NASA measures sea ice and Arctic health, speaking to whaling captains, scientists, locals and three kids in astronaut suits. Woods and others also talked with local researchers working on the tundra with carbon monitoring stations, weather instruments and more.
Karl Newyear, chief scientist with the Ukpeagvik Inupiat Corporation in Barrow, leads a tour of the Barrow Environmental Observatory, where researchers come to study the tundra. Credit: NASA/Kate Ramsayer
This is the first time that IceBridge has been based in Barrow—the farthest north town in the United States. And the mission hopes to use it as a base to fly out again, Woods said.
“It’s an ideal location, between the Beaufort and Chukchi seas,” he said, referring to two of IceBridge’s research destinations. “We couldn’t have gotten better support from the City of Barrow and the local community. They’ve been terrific, and we’d love to see our relationship with them grow.”
The C-130 Hercules from Wallops Flight Facility is being used for Atmosphereic Carbon and Transport-America, a muilti-year airborne campaign that will measure concentrations of two powerful greehouse gases, carbon dioxide and methane, in relation to weather systems in the eastern United States.
by Mark Kaufman and MaryAnn Jackson / Hampton, Va. /
Atmospheric Carbon and Transport – America, or ACT-America, kicked off July 18. Here are ten things we think you should know about this aiborne field campaign:
The ACT-America study will last 5 years. Each airborne campaign will last six weeks and fly during every season: fall, winter, spring and twice during the summer over the eastern United States.
Other than studying the transport, sources and sinks of carbon dioxide, ACT-America seeks to better understand the sources of methane release into the atmosphere. Methane is an especially potent greenhouse gas—“pound for pound,” a methane emission has 25 times the warming effect of carbon dioxide. (Source: https://www3.epa.gov/climatechange/ghgemissions/gases/ch4.html)
In the United States, the Environmental Protection Agency estimates that the digestive processes of domestic livestock, like cattle and sheep, produce 22 percent of the country’s methane emissions. Globally, however, these animals are believed to be the primary contributors to methane emissions.
Both ACT-America planes, the C-130 and B-200, are fitted with instruments that actively take in bits of the atmosphere as they fly over the rural and urban areas of the United States.
The larger of the two ACT-America planes, the C-130, can stay aloft in eastern American skies for up to 8 hours, cutting “lawnmower” patterns through the atmosphere.
During the growing season, forests serve as effective carbon sinks, taking carbon dioxide from the air and turning it into leaves and other plant matter. During winter, however, when leaves drop and plants decay, these same forests become sources. But are these forests net sinks or net sources of carbon dioxide? ACT-America intends to find out.
At times, the C-130 aircraft will fly underneath, or “under-fly,” a NASA satellite called the Orbiting Carbon Observatory – 2 (OCO-2). Like ACT-America, OCO-2 measures the carbon dioxide in the atmosphere in order to characterize its sources and sinks. ACT-America’s measurements will help to evaluate the accuracy of the satellite’s observations.
Terrestrial ecosystems, like farms and forests, remove one-fourth of anthropogenic carbon dioxide emissions from the atmosphere. ACT-America wants to better understand where this is happening and how these sinks might evolve in the future.
ACT-America is flying over the eastern United States—regions east of the Rockies—because they provide ideal environments to study the transport, release and absorption of carbon: lively and dynamic weather systems, abundant forests and farms, cities, and productive industries.
Understanding how weather moves carbon around the atmosphere will benefit our understanding of an uncertain climatic future. In five years, says Principal Investigator Ken Davis, “we should be able to better manage and predict the future climate.”
From 1500 feet above the Chukchi Sea, Operation Icebridge sees melt ponds, ridges and other topography on ice floes. Credit: NASA/Kate Ramsayer
by Kate Ramsayer / BARROW, ALASKA /
In July the Chukchi Sea, 300 miles north of Barrow, Alaska, is as varied as any land terrain.
Sheets of floating ice called floes are cracked into pieces like pottery shards and are dotted with ponds of melted snow. The deepest blue ponds, whose dark colors signify melting that’s occurring in thicker ice, connect to neighbors with winding black rivers that empty into the open sea. Giant chunks of ice form rough ridges where ocean currents and winds have slammed the ice floes into each other.
It’s summertime in the Arctic, and the ice is in flux.
“I’ve flown in the spring lots of times, and then the Arctic ice cover is just a flat expanse, it just goes out forever,” said Nathan Kurtz, Operation IceBridge project scientist from NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Now, in the summer, it’s just so variable. You see places where the floes are a lot more broken up, you see a mixture of places where the snow has melted and you see bare ice, and various depths of melt ponds … you see these patches all over of ice in different stages of melt.”
Melt ponds in the summer could be an indicator of this year’s Arctic sea ice extent at the September minimum. Credit: NASA/Kate Ramsayer
Operation IceBridge made two flights out of Barrow on Tuesday, July 19, as part of the campaign’s first effort to take airborne measurements of melting summer sea ice. Flying 1,500 feet above the ice floes were three instruments: a laser altimeter that measures the heights of the water, snow and ice; an infrared imager that provides temperature readings to help differentiate between water and ice; and a downward-facing mapping camera.
“We’ve never mapped melt ponds so extensively like this,” Kurtz said. And there were many melt ponds to map, as stretches of open water dotted with ice alternated with stretches of ice dotted with ponds and open water.
On the first flight, fog in Barrow and cloudy skies for the first couple hundred miles cleared up just as the agency’s Falcon jet, out of NASA’s Langley Research Center, reached the line the scientists wanted to measure. The goal? Take readings along the path that the European Space Agency’s CryoSat-2 would fly over shortly after 3 pm, local time. That would provide ways to compare the satellite and airborne data and see if scientists could use the summer satellite data.
Instruments on NASA’s Falcon jet monitor the sea ice in the Chukchi Sea below. Credit: NASA/Kate Ramsayer
Then, early Tuesday evening, the team took off on another flight to the northeast. This flight was designed to see the patterns and topography of sea ice in the Beaufort Sea along a path dubbed the Linkswiler line, after Matt Linkswiler, operator of the laser altimeter.
Kurtz and his colleagues are investigating whether a combination of measurements can help estimate sea ice thickness. It’s a tricky piece of information to get, but one that could provide clues to how fast the summer ice will melt, or whether it could stick around for another year.
They’re studying how well the laser altimeter can measure the depths of the melt ponds—another possible indication of the year’s overall melt season. It’s one of several ways the IceBridge campaign is preparing for the Ice, Cloud and land Elevation Satellite-2, or ICESat-2, scheduled to launch by 2018. How IceBridge can measure summer ice melt could help ICESat-2 scientists develop programs to analyze the satellite’s summer data.
Sea ice melts off the beach of Barrow, Alaska, where Operation IceBridge is based for its Summer 2016 campaign. Credit: NASA/Kate Ramsayer
For Kurtz, the sheer variety of the summer ice is surprising and was especially noticeable on the Tuesday afternoon flight. Different shades of white gave hints to whether it was just ice or snow on top of the ice, while in some areas the ice was brown, possibly due to embedded algae, Kurtz noted.
After Tuesday’s two flights, Icebridge had completed five of its six planned flights for the Barrow summer campaign. With its clear skies, Tuesday afternoon’s expedition was the best yet.
“That was an excellent flight,” Kurtz said over the plane’s intercom system. “I don’t think we lost anything to clouds.”
