This summer, a team of scientists launched the Greater New York Oxidant Trace Gas Halogen and Aerosol Airborne Mission (GOTHAAM), an extensive airborne study aimed at tracking air quality above New York City. The project, funded by the National Science Foundation (NSF), is the largest campaign of its kind to measure smog precursors in the region.
Led by John Mak, professor at Stony Brook University’s School of Marine and Atmospheric Sciences (SoMAS), GOTHAAM brings together researchers from more than seven universities as well as the National Center for Atmospheric Research (NCAR). The research group included SoMAS Professor Daniel Knopf, SoMAS Dean Paul Shepson, and Christine Gilbert, assistant professor in both the School of Communication and Journalism and SoMAS.
For six weeks, the team operated out of MacArthur Airport on Long Island. They conducted over 20 research flights using the NSF/NCAR C-130 aircraft—a large flying laboratory equipped with up to 13,000 pounds of scientific instruments. This aircraft allowed scientists to collect detailed atmospheric data across diverse environments ranging from city streets to forests and coastal areas.
“GOTHAAM is an intensive New York City-centric intensive field campaign that really focuses on the unique set of circumstances in this region,” said Mak. “The population and industrial strength coupled with its location next to huge swaths of active forested areas, as well as being adjacent to the Atlantic Ocean, means you have three distinct areas all mixing together. In addition, we now have wildfire smoke to contend with regularly. This leads to a wide range of chemical processes that we don’t fully understand. We want to understand those processes and the products, and how they impact our lives. The understanding we gain from this study will be directly translatable to other metropolitan areas around the world.”
Air pollution remains a concern in New York’s metropolitan area, especially during summer months when ozone levels can exceed federal health standards at several monitoring stations. While regulatory measures have reduced fine particulate pollution over recent decades, other sources—such as vehicle emissions, industrial activity, consumer products, and vegetation—continue to contribute to smog formation. These pollutants can worsen respiratory and heart conditions and impact local ecosystems.
To analyze these issues in detail, researchers used advanced tools like mass spectrometers, particle analyzers, and laser sensors capable of detecting hundreds of chemicals in real time during flights lasting six to eight hours each. By sampling air from forests through urban centers out toward the ocean—and capturing data both day and night—the mission seeks a comprehensive view of atmospheric chemistry across environments.
A key focus is volatile organic compounds (VOCs), which are central in forming ground-level ozone and particulate matter. VOCs come from sources including vehicles, buildings, industry sites, consumer goods such as cleaning sprays or paints, and nearby forests. Emissions from wooded areas near highways or city edges may even surpass those from undisturbed forests; when these natural gases mix with urban pollutants they create more reactive chemical interactions.
Nighttime atmospheric chemistry is another major research area for GOTHAAM. Unlike daytime reactions driven by sunlight, nighttime processes involve different compounds like nitrate radicals or chlorine derived from sea salt—which can accumulate overnight before releasing pollutants after sunrise.
By flying missions during both daylight and nighttime hours throughout their campaign period, researchers hope to document these changing chemical dynamics.
“As you can imagine, it takes some time to figure out what all these data are telling us,” said Mak. “Each instrument group — and there are about a dozen different groups — is tasked with getting their specific final data set ready for analysis, which takes a few months, and then we will be using different tools to figure out what is going on. The process will take many months.”
Results from GOTHAAM are expected over the coming year; however researchers believe that this dataset will serve as an important baseline for future studies on pollutants and ozone levels in New York City’s atmosphere for years ahead. Insights gained could inform efforts aimed at improving public health not only locally but also in cities worldwide facing similar challenges.
