Taking Flight
Two atmospheric professors combine piloting and research, conducting in-flight studies that span urban, Arctic and coastal environments
BY Greg Filiano
John Mak (left) and Paul Shepson (right) at Brookhaven Calabro Airport, where their research aircraft await their next mission.
John Mak and Paul Shepson are a unique tandem of university professors. Both are scientists who investigate atmospheric composition in relation to climate change. Both are pilots who use their own planes to conduct air sampling — two of the very few university scientists doing this worldwide. Both teach at Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS).
There is, however, a difference in their paths to the cockpit. As an undergraduate student in California, Mak planned a career as a Navy pilot. Those plans changed, but his passion for flying didn’t. Shepson, an outdoorsman, didn’t consider piloting until well into adulthood. While teaching at Purdue University, his office was near the airfield where student pilots trained. One day he decided to take up flight — not for research, but simply “because you can.”
Years later, Shepson — SoMAS dean and a SUNY Distinguished Professor, and Mak are colleagues at the same university, where they study the chemical composition of Earth’s atmosphere. While their core areas differ — Shepson concentrates on the remote, sparsely populated Arctic and Mak investigates air over the densely populated New York City region — they share an interest in atmospheric chlorine chemistry. Both use their planes to study these chemicals in vastly different environments.
Shepson at the controls.
Shepson has flown his own plane in two-month campaigns (2012 and 2022) over the Alaskan Arctic. He and his colleagues examine how human-induced climate change may be altering atmospheric chemistry — a process highly impacted by sea ice. His current work centers on a study called CHACHA, short for CHemistry in the Arctic — Clouds, Halogens and Aerosols.
Mak’s research has culminated in a project called GOTHAAM, or the Greater New York Oxidant Trace Gas Halogen and Aerosol Airborne Mission. As lead principal investigator, Mak heads a collaborative effort that includes Shepson and SoMAS professors Daniel Knopf and Christine Gilbert. To gather the necessary data, Mak and his team used an NSF C-130 transport airplane that was flown throughout the greater New York City region, spanning the metro area, coastal zones and the mountainous terrain of Pennsylvania.
Out of the Woods
Growing up in New York’s Finger Lakes region, Shepson enjoyed outdoor activities like fishing and skiing. He chose SUNY Cortland for his undergraduate studies in the 1970s partly for the school’s proximity to ski areas.
While Shepson was always interested in the environment, an environmental chemistry course sparked his mission to protect Mother Earth.
“I wanted to have passion like a teacher I had at the time, who taught us about the environment and how it all works together and that we were desecrating it with chemicals like DDT and other pollutants,” said Shepson. “My passion grew for this miracle that is Earth.”
Shepson and his team brave the Arctic cold as they prepare the aircraft to take readings.
Saving it quite literally became Shepson’s religion. His scholarly interest in environmental chemistry continued at Pennsylvania State University, where he earned a PhD in atmospheric chemistry in 1982. After various positions as a research chemist in industry, he launched his academic career, first at York University in Toronto and later at Purdue University in Indiana, serving from 1994 to 2018 before being named dean of SoMAS.
“I have always believed that science and fun should go together,” Shepson said. “My philosophy expressed to new faculty at Stony Brook is to pick what you would really enjoy doing, then go do it — better than anyone else.”
However, he admits that he kind of “stumbled into” using his own plane for Arctic research.
Since the late 1980s, Shepson has conducted Arctic research, making roughly 20 trips to study the changing environment and its impact on indigenous communities, including Greenland and Utqiagvik, Alaska. Until 2012, however, his work remained grounded. Those ventures were a mix of adventure, cultural learning and atmospheric study. Aviation-based research would come later.
“People don’t ski in Indiana, you are not in a coastal region, so two of the only things to do for fun are golf and aviation,” Shepson said. “Purdue has an aviation school, and my office looked right into the airfield. I would see all these kids learning to fly and [realized] I needed an avocation. I decided, why not learn?”
Mak’s new plane arrives this summer. The 1960 Beech G18S “Super 18,” a twin-engine, low-wing tailwheel aircraft, will broaden the scope of his research.
Shepson struck a deal with Purdue’s aviation department: If he bought one of their planes, they would provide flight training and, in return, he would involve them in “cool” science. The arrangement worked perfectly.
At age 39, Shepson was on his way to becoming a licensed pilot.
“It took at least a half a year to realize I could combine flying with my atmospheric research,” Shepson said. “I started working with engineers to develop instrumentation that could sample air and mirror my lab. Eventually we had a great system to do that with the flights. This began my journey to conducting atmospheric measurements that led to our discoveries in the Arctic.”
Shepson and his colleagues also developed methods to quantify the greenhouse gas emissions dramatically changing the Arctic landscape. After studying the air over Indianapolis, they expanded their work to other U.S. cities, including New York City, to compare regional climate impacts.
As Shepson deepened his fascination with Alaskan native culture — specifically the community’s heritage and reliance on the land and sea — he witnessed the loss of sea ice due to climate change. This served as a catalyst for him to get off the Arctic ice and take to the air. In 2012, NASA funded his mission to conduct atmospheric measurements along Alaska’s North Slope.
Shepson retrofitted his plane for extreme cold and completed his first Arctic research campaign in 2012. The work was a success, and the mission revealed how snow and ice dictate atmospheric composition in the Arctic. This success led to a National Science Foundation (NSF) grant to start CHACHA. Between February and April 2022, Shepson flew approximately 40 missions out of Utqiagvik, using specialized instrumentation to collect vast amounts of atmospheric data.
A life-changing event occurred en route to Alaska in northern British Columbia, where he encountered an unpredicted snowstorm. Flying through that was an intense experience, and Shepson described the flight, which was diverted to safety at a small airfield, as “pretty hairy” and dangerous. After landing safely, Shepson — a commercial pilot — vowed never to face such a situation again.
All the intended flights for the project were successfully completed and Shepson and his colleagues are now analyzing all the data collected from the mission. He said the danger of flying in sub-zero conditions is another reason he decided the 2022 mission would be his last flight in the Arctic. But he has been doing other aviation-based scientific missions with his airplane, around the northeast coast. “It is much safer flying around Long Island!” Shepson said.
The plane used for CHACHA was sent back to Indiana earlier this year, and Shepson is hoping it will land in a science museum.
A Career Takes Off
Shepson and Mak before taking a ride around Long Island earlier this year. It was the first time Mak was Shepson’s passenger.
Unlike Shepson, Mak had been interested in flying since his teens in California. As a senior at the University of California, Irvine, he was set to graduate and enter the Navy as a pilot.
“At that time, my interests had grown, and I was torn between going to law school, continuing with my interests in atmospheric chemistry or flying for the military,” Mak said. “I was accepted into the U.S. Navy’s Aviation Officer Candidate School in Florida, but at the very last minute before deciding, I got word that the Scripps Institution for Oceanography at UC San Diego would give me a free ride to go to graduate school. To learn more about science and conduct research for free while living near the beach and my hometown looked pretty good to me.”
Mak chose graduate school to focus on marine and atmospheric research, though he kept his eye on flying. During his free time, he rode his motorcycle toward Miramar to observe military aircraft take off from the naval base in San Diego.
Throughout the 1990s, Mak delved further into atmospheric research. Opportunities arose that required flights to collect air samples. He spent time working and living in New Zealand and Colorado — first as a doctoral student at Scripps and later as a full-time scientist.
Mak’s current experimental plane, which has flown thousands of miles in the pursuit of data.
“I learned a lot about flying, the scientific equipment on board and what needs to be done for atmospheric sampling during those flights,” Mak said. “Our scientists completed atmospheric testing that had not really been done before and are used today. We measured things like radiocarbon and carbon monoxide and estimated how long these gases might stick around in the atmosphere — all key aspects to understanding what controls the fate of everything that is released into the air.”
Mak continued his atmospheric science research into the 2000s, having accepted an academic appointment to Stony Brook, joining the faculty of SoMAS’ Institute for Terrestrial and Planetary Atmospheres in 1995. In 2007, while serving at Stony Brook under a special NSF program to direct atmospheric science research, Mak attended a presentation by an NSF geologist in the Washington, D.C., area. He said the talk gave him a jolt, signaling where his own research and career should head next.
“This geologist showed incredible photographs explaining his work on land, photos from the sky and taken from his own plane,” Mak said. “It was a big ‘aha’ moment for me.”
It immediately struck Mak that he could combine his love for flying with his atmospheric work, conducting research directly from his own plane.
Mak quickly moved to recertify for specific flight training categories. By 2010, he was using his own planes for research, with his first few scientific missions conducted in Colorado and Alabama.
He enjoyed flying so much that he considered leaving academia to become a commercial pilot for international NGOs. Ultimately, however, Mak decided that combining his love for atmospheric science with his passion for flying and teaching remained his best career choice.
“The real path to what we are doing now began there. I have found that my flying is like my scientific work — it is always evolving, I learn new things and look for new ways to expand what can be done,” Mak said.
Flights of Discovery
The NSF-supported GOTHAAM project began in the early 2020s, with Mak and his team completing 21 research flights in the summer of 2025 alone. They are now analyzing air samples to determine how chemical reactions and emissions affect air quality. Mak expects the results will lead to new insights into how forests, oceans and urban areas affect air quality across the New York metropolitan region and its surroundings.
In 2013, Mak, here with engineering students, took to the skies over Talladega National Forest near Brent, Alabama, to examine emissions from trees from above the canopy to see how they impact aerosol formation.
New research in the Caribbean is on the horizon, supported by a specialized airplane Mak recently purchased from a private owner. He said the new plane will elevate their ability to use flight to better understand the atmosphere, taking their research to a whole new level.
“This is an amazingly durable and cool-looking aircraft that is an iconic plane built in 1960. It can run slow, which helps us with our research, is spacious and has room for all kinds of equipment and instrumentation we need for our pending flights,” he said.
The project centers on the island of Barbados, where scientists are investigating why methane appears to be removed from the atmosphere naturally and efficiently. Typically, methane degradation is a much slower process.
Mak said that this phenomenon is unusual and potentially significant. Upcoming flights over Barbados and the Caribbean may reveal why this occurs and whether it happens in other regions globally. While the team has tested other areas, they have yet to observe this phenomenon anywhere else.
The next research mission to the Caribbean is scheduled for January 2027.
These ongoing questions and mysteries — such as the Caribbean methane phenomenon —drive Mak and Shepson to continue their research in the search for answers, one flight at time.
Below, shots from Shepson from past trips to the Arctic.
