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Published August 28, 2025 | Version Published
Journal Article Open

Global Observations of Acetyl Peroxynitrate (PAN) in the Remote Troposphere

Creators

  • 1. ROR icon Georgia Institute of Technology
  • 2. NOAA Chemical Sciences Laboratory
  • 3. ROR icon California Institute of Technology
  • 4. ROR icon National Center for Atmospheric Research
  • 5. NOAA Global Monitoring Laboratory
  • 6. ROR icon Cooperative Institute for Research in Environmental Sciences
  • 7. ROR icon Goddard Space Flight Center
  • 8. ROR icon Morgan State University

Abstract

We present global airborne observations of acetyl peroxynitrate (CH3C(O)OONO2, PAN) in the remote troposphere from the Atmospheric Tomography (ATom) campaign. These observations show that biomass burning is the dominant source of PAN in the Southern Hemisphere (SH). In the Northern Hemisphere, anthropogenic emissions from Asia and Europe also contribute significantly to PAN over the Pacific and Atlantic Oceans. Model simulations underestimate PAN in the lower troposphere, in part, due to the underestimation of local production driven by acetaldehyde oxidation and βNO2 (the ratio of acetyl peroxy radicals reacting with NO2 relative to other pathways). The significant impacts of biomass burning evident in the ATom PAN observations suggest that improving model treatment of plume transport and the conversion of NOx to PAN in biomass burning plumes is a viable focus for better simulating PAN. Global observations of PAN provide a benchmark for the evaluation of satellite observations and model simulations of PAN.

Copyright and License

© 2025. The Author(s). This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Acknowledgement

The PAN observations and analysis were supported by NASA Grants NNX15AT90G and 80NSSC23K0826. This material is based upon work supported by the NSF National Center for Atmospheric Research, which is a major facility sponsored by the U.S. National Science Foundation under Cooperative Agreement No. 1852977. The GMI CTM was supported by the NASA Modeling, Analysis and Prediction (MAP) program. The NASA High-End Computing Program (HEC) provided computational resources through the NASA Center for Climate Simulation (NCCS) for the GMI CTM simulation.

Data Availability

The data used in this work is available from the ATom campaign archive at https://doi.org/10.3334/ORNLDAAC/1925 (Wofsy et al., 2021). The GMI modelling results for the ATom campaign are available at https://doi.org/10.3334/ORNLDAAC/1897 (Strode et al., 2021).

Supplemental Material

Supporting Information S1 (DOCX)

Files

Geophysical Research Letters - 2025 - Lee - Global Observations of Acetyl Peroxynitrate PAN in the Remote Troposphere.pdf

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Additional details

Related works

Is supplemented by
Supplemental Material: https://agupubs.onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1029%2F2025GL115001&file=2025GL115001-sup-0001-Supporting+Information+SI-S01.docx (URL)
Dataset: 10.3334/ORNLDAAC/1925 (DOI)
Dataset: 10.3334/ORNLDAAC/1897 (DOI)

Funding

National Aeronautics and Space Administration
NNX15AT90G
National Aeronautics and Space Administration
80NSSC23K0826
National Science Foundation
1852977

Dates

Accepted
2025-07-28
Available
2025-08-18
Version of record online
Available
2025-08-18
Issue online

Caltech Custom Metadata

Caltech groups
Division of Geological and Planetary Sciences (GPS), Division of Engineering and Applied Science (EAS)
Publication Status
Published