As the world continues to witness unprecedented growth in air travel, a groundbreaking study published in Communications Earth & Environment reveals alarming insights into the global repercussions of accelerating aircraft emissions on air quality and human health. This landmark research meticulously quantifies how expanding aviation activities contribute to deteriorating atmospheric conditions and exacerbate public health crises worldwide, underscoring an urgent need for global policy interventions and technological innovation.

The aviation sector, responsible for a substantial portion of anthropogenic greenhouse gas and pollutant outputs, has long been scrutinized for its environmental footprint. Yet, the intricate dynamics linking aircraft emissions to widespread air quality degradation and subsequent health implications have remained largely underexplored until now. Quadros, Nelen, Snellen, and colleagues harnessed sophisticated atmospheric modeling techniques combined with epidemiological data to elucidate these complex pathways with unprecedented precision.

Aircraft engines emit a cocktail of pollutants, including nitrogen oxides (NOx), particulate matter (PM), volatile organic compounds (VOCs), and carbon dioxide (CO2). These emissions initiate a cascade of atmospheric chemical reactions, creating secondary pollutants such as ozone and fine particulate matter, which profoundly impair air quality. The study’s simulation results reveal that aircraft emissions alone contribute significantly to elevated ground-level ozone concentrations, particularly in densely populated and heavily trafficked air corridors.

One of the study’s pivotal findings focuses on the spatial distribution of pollution burdens. Regions adjacent to major airports and common flight routes exhibit air quality dips notably beyond local vehicular and industrial contributions. The researchers found that the transboundary nature of aircraft emissions facilitates the transport of chemically reactive species across continents, linking aviation activities not only to local but also to regional and global air pollution episodes.

In terms of human health, the implications are disturbing. The researchers applied integrated exposure-response functions to estimate the morbidity and mortality attributable to aviation-induced pollution. Their assessments suggest a substantial increase in respiratory ailments, cardiovascular diseases, and premature deaths attributable to aircraft emissions. Particularly vulnerable populations, such as urban dwellers, children, elderly individuals, and those with preexisting conditions, face disproportionate risks.

Moreover, the study highlights the synergistic effects of aircraft emissions with other urban pollutants, exacerbating harmful synergistic interactions that amplify health risks. For instance, the NOx and VOCs emitted interact under sunlight to generate ozone, a potent respiratory irritant, and exacerbate asthma symptoms. The authors stress the importance of recognizing these nonlinear effects for robust public health policy formulation.

Climate feedback mechanisms linked to aviation emissions emerge as a critical concern in the report. The authors delineate how nitrogen oxides released at high altitudes not only affect surface-level ozone but also perturb the radiative balance of the atmosphere. This creates complex feedback loops that potentially accelerate climate warming, indicating that the environmental cost of aviation extends beyond conventional pollutants to include broader climatic impacts.

Technology advances and mitigation strategies receive thorough evaluation in the study. The authors discuss current emission reduction technologies such as lean-burn engines, sustainable aviation fuels (SAFs), and operational measures like optimized flight paths and altitude adjustments. Despite their promise, the research cautions that without comprehensive adoption and scaling, these technologies alone may fall short of offsetting the forecasted growth in emissions.

The aviation sector is projected to expand considerably over the coming decades, driven by economic growth and increasing globalization. The study’s projections indicate that without stringent regulatory frameworks and aggressive emission reduction commitments, the global burden of aviation-induced air pollution and related health impacts will escalate dramatically, particularly in emerging economies with rapidly growing air traffic.

Policy recommendations form a cornerstone of the researchers’ conclusions. They advocate for coordinated international efforts to tighten emission standards, mandate SAF usage, and invest in next-generation propulsion technologies such as electric and hydrogen-powered aircraft. Furthermore, integrating aviation sector goals into broader air quality management and climate policies is deemed essential to maximize health and environmental benefits.

In addition to technological and regulatory measures, the report emphasizes the role of real-time monitoring networks and data-sharing frameworks. Enhanced surveillance of aircraft emissions and their atmospheric transformations can enable dynamic policy responses, better inform public health advisories, and foster transparency and accountability among stakeholders ranging from airlines to regulators.

The health economics dimension discussed in the study reveals enormous societal costs tied to aviation-related air pollution. Hospitalizations, lost productivity, and long-term healthcare expenditures attributed to pollution-induced diseases impose substantial financial burdens on governments and communities alike, reinforcing the public health imperative for aggressive mitigation.

Further research priorities identified in the report call for improved characterization of ultrafine particles emitted by aircraft engines, nuanced understanding of population exposure patterns near airports, and exploration of co-benefits arising from simultaneous air quality and climate interventions. Interdisciplinary collaboration combining atmospheric science, epidemiology, engineering, and policy studies is championed as the pathway to innovative solutions.

In light of this new research, the aviation industry stands at a crossroads. Balancing the undeniable economic and social advantages of air travel with its adverse environmental and health externalities necessitates transformative thinking and collaborative global action. The study’s revelations provide an indispensable scientific foundation for stakeholders to forge a sustainable aviation future.

This comprehensive investigation serves as a clarion call for urgent recognition of the aviation sector’s hidden consequences, urging policymakers, industry players, and the public to engage in proactive, science-informed strategies that safeguard air quality and human health on a planetary scale.

Subject of Research:
The study focuses on evaluating the global impact of increasing aircraft emissions on air quality and related human health outcomes, analyzing both direct and indirect effects through sophisticated atmospheric and epidemiological modeling.

Article Title:
Global air quality and human health impacts of growing aircraft emissions

Article References:
Quadros, F.D.A., Nelen, R., Snellen, M. et al. Global air quality and human health impacts of growing aircraft emissions. Commun Earth Environ (2026). https://doi.org/10.1038/s43247-026-03732-4

Image Credits: AI Generated

DOI: 10.1038/s43247-026-03732-4

Keywords:
Aircraft emissions, air quality, human health, nitrogen oxides, particulate matter, ozone formation, aviation pollution, atmospheric modeling, public health impact, sustainable aviation fuels

Residential segregation remains one of the most pressing and persistent challenges facing American cities today. It fractures economic opportunity, stifles social cohesion, and underpins many of the inequities visible across urban landscapes. Despite decades of research into the patterns and consequences of segregation, the measurement of these patterns has long grappled with a thorny methodological problem: how the artificial boundaries used to aggregate population data influence estimates of segregation. This problem, often called the modifiable areal unit problem (MAUP), arises because segregation indices depend critically on how spatial units—like Census tracts—are defined and aggregated. Until now, a comprehensive assessment of this source of variability has remained out of reach.

In a groundbreaking study published in Nature Cities, researchers have employed an innovative approach that leverages redistricting algorithms to simulate millions of alternative spatial boundary configurations. These alternative maps adhere to official Census criteria but shuffle tract boundaries within those parameters, creating an unprecedented way to probe how sensitive traditional segregation indices are to the arbitrary boundaries that political and statistical geographies impose. The results challenge established assumptions and ultimately affirm the practicality—and peculiar robustness—of Census tracts as tools for racial segregation measurement across U.S. cities.

Traditionally, segregation research relies on fixed geographic units, most commonly Census tracts, to evaluate how populations of different racial and ethnic groups are distributed across cities. But these tracts, while designed to be relatively homogeneous and stable, are shaped by administrative decisions that do not directly correspond to natural or social boundaries. Since the exact delineation of these tracts can stray substantially, estimates of segregation derived from them have always carried a hidden risk of aggregation bias. Sensitivity analyses that explore alternate aggregations have been limited in scope, relying on hypothetical adjustments or crude spatial aggregations, rather than systematically exploring the vast universe of plausible boundary alternatives.

The new study breaks this impasse by borrowing tools from political redistricting theory—where map-drawing is a highly contested and technically advanced field. The researchers developed a computational framework using redistricting software capable of generating millions of alternate Census tract configurations within each city. These alternative configurations satisfy Census Bureau guidelines on population equality and contiguity, approximating what feasible boundary revisions might realistically look like. By calculating segregation indices for each configuration, the team was able to characterize the full probabilistic distribution of segregation estimates that arise purely from boundary variability.

Their analysis covered a wide range of U.S. cities, from smaller metropolitan areas with relatively few tracts to sprawling urban agglomerations comprising thousands of tracts. The findings reveal a striking pattern: in smaller cities, the estimated levels of racial segregation can fluctuate substantially when alternative boundary maps are considered. This variability highlights the dangers of over-reliance on fixed census geographies in contexts where granularity is limited and aggregation artifacts become significant. In contrast, as city size grows and spatial units multiply, the observed segregation estimates converge; the impact of redrawing boundaries diminishes, and estimates become more stable and trustworthy.

Perhaps more surprisingly, the study found no evidence that existing Census tract-based estimates are systematically biased in either direction. The official tract boundary estimates tended to fall near the mean of the simulated distribution of alternative boundaries. This outcome challenges the often-expressed concern that Census tracts might drastically overstate or understate segregation. Instead, while individual estimates do carry inherent spatial aggregation uncertainty, the conventional measures are, on average, representative. This nuance adds an important layer of confidence to decades of segregation research relying on these geographic units.

Technically, the probabilistic distributions generated by the redistricting simulations provide a novel way to frame segregation statistics in an uncertainty framework. Instead of presenting segregation as a point estimate, urban researchers and policymakers can now appreciate a spectrum of plausible segregation values conditioned on boundary choices. This opens avenues for more transparent reporting that reflects the inherent spatial ambiguity in aggregate data analysis, empowering better-informed decisions on interventions aimed at mitigating segregation and its effects.

The methodology itself is noteworthy for blending urban demographics with advanced computational geography. By applying constraints like population equivalence and spatial contiguity, the simulations closely mimic the federal redistricting process and ensure that the alternative boundaries are grounded in realistic criteria rather than purely theoretical constructs. This rigor elevates the findings beyond mere sensitivity checks, framing boundary uncertainty as a quantifiable dimension of segregation research rather than a theoretical limitation.

These insights carry significant implications not only for researchers but also for policymakers and activists engaged in urban planning, housing, and civil rights advocacy. Recognizing that reported segregation metrics come with an intrinsic range of variance caused by how boundaries are drawn can lead to greater caution in interpreting city rankings or trends over time. More fundamentally, it signals the need for complementary approaches that integrate non-aggregate data sources or spatially continuous methods to further refine segregation measurement.

The study also presents a generalizable framework adaptable to other domains where spatial aggregation introduces bias and uncertainty. Fields such as public health, environmental justice, and economic geography often rely on aggregated spatial data vulnerable to the MAUP. The redistricting simulation approach offers a powerful template for diagnosing and statistically correcting aggregation error in these varied contexts, paving the way for more robust spatial analyses across disciplines.

One of the most profound contributions of this research is its nuanced vindication of the Census tract as a unit of analysis. While researchers have long critiqued the arbitrariness inherent in fixed administrative boundaries, the study’s results demonstrate that in many urban contexts at scale, these units provide a sufficiently stable foundation for measuring segregation. This balancing of skepticism with empirical validation is rare in social science and signals a promising path toward methodological refinement rather than wholesale rejection of conventional metrics.

The findings also underscore the importance of city size and spatial scale in segregation measurement. Smaller cities, where the number of spatial units is limited, experience much greater volatility in segregation estimates. This volatility arises because each tract, or aggregation unit, represents a larger proportional share of the city’s population, amplifying boundary effects. Larger cities benefit from statistical smoothing through numerous smaller units, increasing estimate robustness. This insight could deeply inform urban comparative studies and the design of equitable zoning or integration policies tailored to city scale.

Going forward, the authors advocate for broad adoption and further development of their redistricting simulation platform. Enhancing the tool’s accessibility and integrating it with standard segregation calculations could democratize this approach, allowing urban researchers everywhere to rigorously address aggregation bias. Moreover, expanding simulations to explore additional boundary constraints or to incorporate social network data could refine understanding of how human geography and administrative geography intersect to shape segregation patterns.

The study arrives at a critical moment, as U.S. cities grapple with evolving demographic realities amid ongoing debates over race, equality, and urban policy. Precise and reliable measurement tools are foundational to both academic inquiry and effective governance. By making segregation measurement more transparent and statistically nuanced, this research provides a critical step towards evidence-based urban reform that acknowledges complexity without being paralyzed by it.

In conclusion, this pioneering study reframes the measurement of racial segregation by exposing the variability introduced through spatial aggregation while reassuring researchers and policymakers of the general reliability of established Census tract definitions. By harnessing computational redistricting techniques, it both deepens and democratizes understanding of urban racial geography, offering a blueprint for more rigorous and nuanced measurement in this socially consequential domain. The framework not only enriches segregation studies but sets a new standard for spatial data analysis in the social sciences, inviting an era where measurement uncertainty is openly acknowledged and expertly managed.

Subject of Research:
City-scale racial segregation measurement and spatial aggregation bias in U.S. metropolitan areas.

Article Title:
City racial segregation statistics are robust to aggregation bias.

Article References:
Brown, J.R., Kenny, C.T. & Simko, T. City racial segregation statistics are robust to aggregation bias. Nat Cities (2026). https://doi.org/10.1038/s44284-026-00459-3

Image Credits:
AI Generated

DOI:
https://doi.org/10.1038/s44284-026-00459-3

7:05 am

3:05 pm

7:05 am3:05 pm

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CurtainToggle2-Up

Image Details

TEMPO detected high concentrations of nitrogen dioxide during the morning commute at 7:05 a.m. local time on May 18, 2026 (left), along the New York-Washington corridor.The instrument detected lower levels of the gas at 3:05 p.m. EDT (right), after chemical reactions involving nitrogen dioxide had contributed to elevated ozone concentrations in the afternoon. NASA Earth Observatory images by Michala Garrison.

More than 35 million people live along the New York–Washington corridor and breathe the region’s air. While air quality has improved significantly in recent decades, outbreaks of ground-level ozone remain common, particularly in the warm summer months, when the chemical reactions that produce the pollutant accelerate and stagnant air allows ozone to accumulate.

A reminder of this seasonal phenomenon came earlier than usual in 2026, when a mid-May heat wave prompted the New York State Department of Health and the New York Department of Environmental Conservation to issue a health advisory on May 17 over concerns about ozone. The code orange advisory warned young people, older adults, and those working or exercising outdoors to limit activity due to ozone’s respiratory and cardiovascular health impacts.

As expected, ground-based air-quality sensors operated by state and federal agencies showed ozone reaching unhealthy levels for sensitive groups on May 18, something that typically happens several times per year. Meanwhile, NASA’s TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument observed the event from geostationary orbit 22,000 miles (35,000 kilometers) above the equator, a unique vantage point that allows the sensor to collect frequent observations of air pollution.

TEMPO detects nitrogen dioxide (NO₂), a gas emitted by burning fuels, particularly by motor vehicles, that contributes to ozone formation. “There’s often a clear and interesting pattern in TEMPO’s nitrogen dioxide data during ozone alert days,” said Hazem Mahmoud, an atmospheric scientist at NASA’s Atmospheric Science Data Center at Langley Research Center. “We see high concentrations of nitrogen dioxide during the early morning commute that drop off sharply in the late afternoon as ozone increases.”

The decline occurs as sunlight fuels photochemical reactions involving nitrogen dioxide, volatile organic compounds, and oxygen that lead to ozone formation. By late afternoon, these reactions deplete much of the available nitrogen dioxide, slowing ozone production until the cycle begins again the next day.

The pair of images above underscores the pattern. The image on the left was acquired at 7:05 a.m. local time when nitrogen dioxide concentrations were high during the morning commute. By 3:05 p.m. (right), most of the nitrogen dioxide had declined substantially, and surface ozone levels were elevated (below). Meanwhile, afternoon sea breezes appear to have transported the remaining nitrogen dioxide slightly to the west. Note that the data shown is provisional, and processing methods are still being refined.

Sensors on earlier polar-orbiting satellites, such as OMI (Ozone Monitoring Instrument) and TROPOMI (Tropospheric Monitoring Instrument), sampled nitrogen dioxide over New York once per day. After its launch in 2023, TEMPO began providing data every hour, allowing researchers to track the evolution and dispersion of air pollution at much finer time scales. 

“TEMPO is helping fill data gaps between ground stations and allowing us to ask new questions,” Mahmoud said. The mission provides data that can improve not only air quality forecasts during crisis situations, such as wildfires, but also the atmospheric models used to forecast the daily rhythms of urban pollution. Such models help researchers understand how natural factors such as winds, humidity levels, and air temperatures influence pollution plumes over the course of a day.

TEMPO also detects ozone directly, but determining how much of that ozone is near the surface versus higher in the atmosphere can be challenging. Most of Earth’s ozone resides in the stratosphere, well above the troposphere, where people live and breathe. At times, however, stratospheric ozone can be transported downward into the troposphere. During events known as stratospheric intrusions, it can even descend far enough to affect air quality at the surface and add to the ozone produced at ground level.

By combining TEMPO observations with other sources of information, researchers are studying the processes that influence the distribution of ozone vertically in the atmosphere. On May 18, NASA’s ground-based tropospheric lidar network (TOLNet) in New York City recorded high concentrations of ozone near the surface, indicating that TEMPO was detecting mostly surface-level ozone associated with urban emissions and not ozone aloft, said Mahmoud.

However, on May 19, the same sensor observed a layer of ozone descending from above 5 kilometers (3 miles), he added, a clue that some of the ozone TEMPO detected that day may have originated in the stratosphere. “This is the type of information that leads to better air quality forecast models and more accurate alerts,” Mahmoud said. “Alerts can affect tens of millions of people and lead to disruptions in school, sports, and other activities, so it’s essential that they be as accurate as possible.”

On June 6, New York authorities issued another health advisory for ozone. People interested in following the event can access daily near-real-time TEMPO observations of ozone, nitrogen dioxide, and other gases on NASA’s Worldview browser, on an interactive Harvard & Smithsonian Center for Astrophysics browsing tool, and on NASA’s Earthdata portal.   

NASA Earth Observatory images by Michala Garrison, using TEMPO data from NASA Earthdata. Story by Adam Voiland.

Downloads

Nitrogen Dioxide – May 18, 2026 7:05 AM EDT

JPEG (2.52 MB)

Nitrogen Dioxide – May 18, 2026 3:05 PM EDT

JPEG (2.25 MB)

Ozone – May 18, 2026 5:05 PM EDT

JPEG (2.10 MB)

References & Resources

• Acker, S., et al. (2025) Satellite detection of NO₂ distributions using TROPOMI and TEMPO and comparison with ground-based concentration measurements. Atmospheric Chemistry and Physics, 25(14), 8271-8288.
• City of New York (2024) Community Air Survey Report: 2008-2024. Accessed June 9, 2026.
• Energy Education, Ozone. Accessed June 10, 2026.     
• Environmental Protection Agency (2026, May 13) What is Ozone? Accessed June 9, 2026.
• Environmental Protection Agency (2025, July 10) Basic Information about NO₂. Accessed June 9, 2026.
• Holloway, T., et al. (2025) Satellite data to support air quality assessment and management. Journal of the Air & Waste Management Association, 75(6), 429-463.  
• Lee, J., et al. (2024) The Evolutions and Large-Scale Mechanisms of Summer Stratospheric Ozone Intrusion Across Global Hotspots. JGR Atmospheres, 129(4),e2023JD039877.
• NASA (2026) TOLNet. Accessed June 9, 2026.
• NASA Air Quality (AQ) Monitoring from Space by NASA using TEMPO. Accessed June 9, 2026
• NASA Air Quality (2026) Nitrogen Dioxide. Accessed June 9, 2026.
• NASA Air Quality (2026) Nitrogen Dioxide Trends for US Cities. Accessed June 9, 2026.
• NASA Earthdata (2024, May 3) TEMPO Mission Releases Beta Level 1, 2, and 3 Version 03 Data Products. Accessed June 9, 2026.
• New York State Department of Environmental Conservation (2026, May 18) Air Quality Health Advisory Extended for New York City Metro Region. Accessed June 9, 2026.
• Zhang, J., et al. (2026) Revealing the Formation and Control of NYC Downwind Coastal High Ozone via New TEMPO Observations. Geophysical Research Letters, 53(2),e2025GL117523.

You may also be interested in:

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The post Air Pollution’s Daily Pulse Over the Northeast appeared first on NASA Science.

7:05 am

3:05 pm

7:05 am3:05 pm

7:05 am

3:05 pm

CurtainToggle2-Up

Image Details

TEMPO detected high concentrations of nitrogen dioxide during the morning commute at 7:05 a.m. local time on May 18, 2026 (left), along the New York-Washington corridor.The instrument detected lower levels of the gas at 3:05 p.m. EDT (right), after chemical reactions involving nitrogen dioxide had contributed to elevated ozone concentrations in the afternoon. NASA Earth Observatory images by Michala Garrison.

More than 35 million people live along the New York–Washington corridor and breathe the region’s air. While air quality has improved significantly in recent decades, outbreaks of ground-level ozone remain common, particularly in the warm summer months, when the chemical reactions that produce the pollutant accelerate and stagnant air allows ozone to accumulate.

A reminder of this seasonal phenomenon came earlier than usual in 2026, when a mid-May heat wave prompted the New York State Department of Health and the New York Department of Environmental Conservation to issue a health advisory on May 17 over concerns about ozone. The code orange advisory warned young people, older adults, and those working or exercising outdoors to limit activity due to ozone’s respiratory and cardiovascular health impacts.

As expected, ground-based air-quality sensors operated by state and federal agencies showed ozone reaching unhealthy levels for sensitive groups on May 18, something that typically happens several times per year. Meanwhile, NASA’s TEMPO (Tropospheric Emissions: Monitoring of Pollution) instrument observed the event from geostationary orbit 22,000 miles (35,000 kilometers) above the equator, a unique vantage point that allows the sensor to collect frequent observations of air pollution.

TEMPO detects nitrogen dioxide (NO₂), a gas emitted by burning fuels, particularly by motor vehicles, that contributes to ozone formation. “There’s often a clear and interesting pattern in TEMPO’s nitrogen dioxide data during ozone alert days,” said Hazem Mahmoud, an atmospheric scientist at NASA’s Atmospheric Science Data Center at Langley Research Center. “We see high concentrations of nitrogen dioxide during the early morning commute that drop off sharply in the late afternoon as ozone increases.”

The decline occurs as sunlight fuels photochemical reactions involving nitrogen dioxide, volatile organic compounds, and oxygen that lead to ozone formation. By late afternoon, these reactions deplete much of the available nitrogen dioxide, slowing ozone production until the cycle begins again the next day.

The pair of images above underscores the pattern. The image on the left was acquired at 7:05 a.m. local time when nitrogen dioxide concentrations were high during the morning commute. By 3:05 p.m. (right), most of the nitrogen dioxide had declined substantially, and surface ozone levels were elevated (below). Meanwhile, afternoon sea breezes appear to have transported the remaining nitrogen dioxide slightly to the west. Note that the data shown is provisional, and processing methods are still being refined.

Sensors on earlier polar-orbiting satellites, such as OMI (Ozone Monitoring Instrument) and TROPOMI (Tropospheric Monitoring Instrument), sampled nitrogen dioxide over New York once per day. After its launch in 2023, TEMPO began providing data every hour, allowing researchers to track the evolution and dispersion of air pollution at much finer time scales. 

“TEMPO is helping fill data gaps between ground stations and allowing us to ask new questions,” Mahmoud said. The mission provides data that can improve not only air quality forecasts during crisis situations, such as wildfires, but also the atmospheric models used to forecast the daily rhythms of urban pollution. Such models help researchers understand how natural factors such as winds, humidity levels, and air temperatures influence pollution plumes over the course of a day.

TEMPO also detects ozone directly, but determining how much of that ozone is near the surface versus higher in the atmosphere can be challenging. Most of Earth’s ozone resides in the stratosphere, well above the troposphere, where people live and breathe. At times, however, stratospheric ozone can be transported downward into the troposphere. During events known as stratospheric intrusions, it can even descend far enough to affect air quality at the surface and add to the ozone produced at ground level.

By combining TEMPO observations with other sources of information, researchers are studying the processes that influence the distribution of ozone vertically in the atmosphere. On May 18, NASA’s ground-based tropospheric lidar network (TOLNet) in New York City recorded high concentrations of ozone near the surface, indicating that TEMPO was detecting mostly surface-level ozone associated with urban emissions and not ozone aloft, said Mahmoud.

However, on May 19, the same sensor observed a layer of ozone descending from above 5 kilometers (3 miles), he added, a clue that some of the ozone TEMPO detected that day may have originated in the stratosphere. “This is the type of information that leads to better air quality forecast models and more accurate alerts,” Mahmoud said. “Alerts can affect tens of millions of people and lead to disruptions in school, sports, and other activities, so it’s essential that they be as accurate as possible.”

On June 6, New York authorities issued another health advisory for ozone. People interested in following the event can access daily near-real-time TEMPO observations of ozone, nitrogen dioxide, and other gases on NASA’s Worldview browser, on an interactive Harvard & Smithsonian Center for Astrophysics browsing tool, and on NASA’s Earthdata portal.   

NASA Earth Observatory images by Michala Garrison, using TEMPO data from NASA Earthdata. Story by Adam Voiland.

Downloads

Nitrogen Dioxide – May 18, 2026 7:05 AM EDT

JPEG (2.52 MB)

Nitrogen Dioxide – May 18, 2026 3:05 PM EDT

JPEG (2.25 MB)

Ozone – May 18, 2026 5:05 PM EDT

JPEG (2.10 MB)

References & Resources

• Acker, S., et al. (2025) Satellite detection of NO₂ distributions using TROPOMI and TEMPO and comparison with ground-based concentration measurements. Atmospheric Chemistry and Physics, 25(14), 8271-8288.
• City of New York (2024) Community Air Survey Report: 2008-2024. Accessed June 9, 2026.
• Energy Education, Ozone. Accessed June 10, 2026.     
• Environmental Protection Agency (2026, May 13) What is Ozone? Accessed June 9, 2026.
• Environmental Protection Agency (2025, July 10) Basic Information about NO₂. Accessed June 9, 2026.
• Holloway, T., et al. (2025) Satellite data to support air quality assessment and management. Journal of the Air & Waste Management Association, 75(6), 429-463.  
• Lee, J., et al. (2024) The Evolutions and Large-Scale Mechanisms of Summer Stratospheric Ozone Intrusion Across Global Hotspots. JGR Atmospheres, 129(4),e2023JD039877.
• NASA (2026) TOLNet. Accessed June 9, 2026.
• NASA Air Quality (AQ) Monitoring from Space by NASA using TEMPO. Accessed June 9, 2026
• NASA Air Quality (2026) Nitrogen Dioxide. Accessed June 9, 2026.
• NASA Air Quality (2026) Nitrogen Dioxide Trends for US Cities. Accessed June 9, 2026.
• NASA Earthdata (2024, May 3) TEMPO Mission Releases Beta Level 1, 2, and 3 Version 03 Data Products. Accessed June 9, 2026.
• New York State Department of Environmental Conservation (2026, May 18) Air Quality Health Advisory Extended for New York City Metro Region. Accessed June 9, 2026.
• Zhang, J., et al. (2026) Revealing the Formation and Control of NYC Downwind Coastal High Ozone via New TEMPO Observations. Geophysical Research Letters, 53(2),e2025GL117523.

You may also be interested in:

Stay up-to-date with the latest content from NASA as we explore the universe and discover more about our home planet.

Smoke Shrouds Northern Thailand

3 min read

Seasonal fires have darkened skies over Southeast Asia.

Article

Winter’s End Is Written in the Clouds

3 min read

As winter turned to spring, the skies over the Gulf of Alaska displayed textbook examples of numerous cloud formations.

Article

Extreme January Cold

3 min read

Following a significant winter storm, frigid temperatures lingered in late January 2026 across a vast swath of the U.S.

Article

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By Erica McNamee of NASA’s Goddard Space Flight Center in Greenbelt, MD 

As a kid, you were always taught to hold tight to balloons—tie them around your wrist, even, to keep them close. This week, a group of a dozen undergraduate students participating in NASA’s 2026 Student Airborne Research Program (SARP), unlearned old balloon-wrangling habits—and let go. 

Their purpose:  to collect data about the atmosphere with the help of a weather balloon. For this fieldwork day, in a windy area on the Texas Gulf Coast, the group released an ozonesonde, a small instrument attached to a weather balloon that measures ozone concentrations as it rises through the atmosphere.   

“I’ve never done any atmospheric fieldwork outside like this, so this has been an awesome new opportunity for me,” said Marin Stevens, SARP intern and chemistry student from the University of Colorado at Colorado Springs.  

With the support of program mentors and faculty, and aboard the University of Houston’s Mobile Air Quality Laboratory (MAQL), the SARP interns participated in every step of the process.  

Let’s set the scene: About 45 minutes away from this year’s SARP home base at the Lone Star Flight Museum in Houston, the MAQL drove down the Texas City Dike, a long strip of land jutting into the Texas Gulf Coast—an open space perfect for releasing the weather balloon. Among the 45 total students in the program, this group was assigned to meet the mobile lab at the balloon release location at  8 a.m. Central Time, just after a rainstorm rolled through. 

Inside the lab, the students prepared ozonesondes for takeoff, completing the final steps that include measuring and pipetting cathode and anode solutions into the instrument cells attached to the sensor and testing each instrument’s response and baseline. 

Outside the mobile laboratory, gusts of wind made it difficult to keep the balloon still while it was being filled with helium. Four students donned leather gloves to minimize oils from their fingers touching the balloon, which can make it pop faster after deployment. They wrangled the balloon while faculty advisor Travis Griggs, instructional assistant professor of atmospheric science from the University of Houston, filled it.  

Five students worked together to keep the balloon from flying away as they strung it to the ozonesonde, protected in a small foam container. 

After confirming the launch location, time, and expected flight path with the Federal Aviation Administration (just a phone call away), it was time to set the weather instrument free.   

“It was like a fight to stay on the ground, with the balloon whipping around in the wind,” said Zayna Haider, SARP intern and atmospheric and climate science student from the University of Washington. “It just flew away as soon as we let it go.” 

But the work had only just begun. The students huddled back inside the MAQL, monitoring data as long as the balloon kept sending it—until it popped or landed, whichever came first. Throughout the day, they repeated this process with two other balloons.  

This day gave many SARP participants, just starting their science careers, their first glimpse at hands-on fieldwork that reached the edges of the atmosphere. Next, they would use this data and what they learned from the experience for their end-of-internship research presentation.  

“This is beyond what I ever thought it could be,” Stevens said. “I’m super excited for the next seven weeks.” 

The post Up, Up, and Away With Weather Balloons  appeared first on NASA Science.

Seven men die by suicide in Australia every day. Last month, the peak body for men's health decided to address this by teaching boys about gender equity. But men are not dying for lack of feminism, says Bettina Arndt.

The post Suicidal Men Don’t Need More Feminism appeared first on The Daily Sceptic.

5 Min Read

NASA-Funded Study Shows Wildfire Smoke’s Hidden Ozone Toll

Wildfire smoke is stoking a new challenge for cleaner air. A NASA-supported study published Thursday found that, over the last decade, wildfires have worsened ground-level ozone pollution across much of the contiguous United States, creating unhealthy air far from active flames.

Wildfires have become an increasingly important contributor to ground-level ozone, or smog, across much of the United States, researchers report June 4 in the journal Science. Nationally, fires offset nearly four years’ worth of ozone-control gains, with larger setbacks in the West and Midwest.

Smoke often is associated with the soot, ash, and other fine particles that make the air look hazy. But wildfires also emit gases such as carbon monoxide, which can help form surface ozone in sunlight when other pollutants are present. Surface ozone is an invisible pollutant harmful to human health, plants, and crops. As smoke plumes travel and mix with other pollution, those reactions can drive ozone increases hundreds or even thousands of miles from active fires.

“NASA Earth observations, along with ground monitoring networks, help reveal air quality risks from wildfires that can cross state lines, giving air quality managers better decision-making information as wildfire smoke affects more communities,” said John Haynes, manager of NASA Earth Action’s Health and Air Quality program at the agency’s Headquarters in Washington. “This is a strong example of NASA science serving communities here in the U.S.”

Building a clearer ozone picture

High in the atmosphere, ozone shields Earth from harmful ultraviolet radiation. Near the ground, however, ozone can irritate lungs, worsen asthma and other respiratory diseases, and increase health risks for children, older adults, outdoor workers, and people with existing health conditions.

To track surface ozone changes, researchers turned to deep learning, a form of artificial intelligence that finds patterns across large datasets. They used it to build a first-of-its-kind dataset estimating daily surface ozone from 2003 to 2024 on a kilometer-by-kilometer grid — about 0.6 miles on each side — across the contiguous U.S. The work received support from NASA’s Health and Air Quality program and other NASA grants.

The scientists combined data from about 1,000 ground-based air quality stations with atmospheric model data, weather information, wildfire pollution data, and satellite-derived information, including products from the Visible Infrared Imaging Radiometer Suite (VIIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments.

Their analysis revealed two distinct periods. From 2003 to 2015, U.S. ground-level ozone generally declined as emissions of ozone-forming pollutants decreased. After 2015, however, those gains slowed or reversed in many places. By comparing estimated ozone levels with scenarios that removed wildfire influence, the researchers found that pollution from wildfires was a main factor in that shift.

Without the wildfire contribution, ground-level ozone in the Midwest, for example, would likely have continued to decline. Instead, wildfires erased about 5.3 years’ worth of ozone-control progress since 2015.

“People in the Midwest may think fires burning far away will not affect them,” said the study’s corresponding author Jun Wang, an atmospheric scientist at the University of Iowa in Iowa City. “But once wildfire pollution is in the air, it can move across regions. Pollution from one place can affect air quality in another.”

Measuring the health toll

The study also found that wildfire-driven ozone increased exposure to unhealthy air and likely contributed to premature deaths. Premature deaths associated with long-term wildfire-related ozone exposure in the U.S. increased by an estimated 318 deaths per year after 2013, with the post-2013 average 46% higher than in the previous decade. The researchers calculated premature deaths using average lifespan, ozone exposure estimates, and population density.

The 2023 Canadian wildfires showed how widely those risks can spread, with smoke-driven ozone increases stretching across the Midwest and into parts of the Northeast and South. Overall, from 2022 to 2024, wildfires exposed an additional 43 million people in the U.S. to conditions that did not meet current federal air quality standards for ozone, the researchers estimated.

Capturing that national picture is difficult from ground monitors alone. Ground monitors remain the backbone of U.S. air quality tracking, but they do not cover every community. NASA’s scientifically validated satellite observations and models help researchers and agencies see air quality patterns across states, regions, and fire seasons.

That broader air quality work includes newer missions such as TEMPO (Tropospheric Emissions: Monitoring of Pollution). Launched in 2023, TEMPO is NASA’s first mission to use a space-based spectrometer to provide hourly daytime measurements of air quality over North America. Its view is sharp enough to distinguish pollution patterns, including surface ozone, across areas only a few square miles wide, a major improvement over earlier satellites.

Together, these capabilities help researchers and agencies see smoke-related ozone patterns that might otherwise be harder to detect, especially in rural and remote areas.

The work also points toward a practical use of NASA science during fire season. Wang’s team has used NASA support to develop FireAQ, a decision-support system that brings satellite observations, model forecasts, and fire and aerosol products into weekly briefings with state and local air quality officials. The goal is to help officials see where smoke-related pollution may move next and give communities better information.

About the Author

Emily DeMarco

Writer/Editor (IV), Earth Science Division

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