edu.ucar.opensky::articles:24963 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T22:56:16.647602 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d75h7ksv https://doi.org/10.5281/zenodo.5752566 https Related Software #1 AirChem/F0AM: v4.2.1 with Zenodo DOI Formaldehyde evolution in US wildfire plumes during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ) 2021-12-17T00:00:00Z publication https://n2t.org/ark:/85065/d75h7ksv https://doi.org/10.5194/acp-21-18319-2021 Liao, J. author Wolfe, G. M. author Hannun, R. A. author St. Clair, J. M. author Hanisco, T. F. author Gilman, J. B. author Lamplugh, A. author Selimovic, V. author Diskin, G. S. author Nowak, J. B. author Halliday, H. S. author DiGangi, J. P. author Hall, Samuel R. author Ullmann, Kirk author Holmes, C. D. author Fite, C. H. author Agastra, A. author Ryerson, T. B. author Peischl, J. author Bourgeois, I. author Warneke, C. author Coggon, M. M. author Gkatzelis, G. I. author Sekimoto, K. author Fried, A. author Richter, D. author Weibring, P. author Apel, Eric C. author Hornbrook, Rebecca author Brown, S. S. author Womack, C. C. author Robinson, M. A. author Washenfelder, R. A. author Veres, P. R. author Neuman, J. A. author UCAR/NCAR - Library publisher Formaldehyde (HCHO) is one of the most abundant non-methane volatile organic compounds (VOCs) emitted by fires. HCHO also undergoes chemical production and loss as a fire plume ages, and it can be an important oxidant precursor. In this study, we disentangle the processes controlling HCHO by examining its evolution in wildfire plumes sampled by the NASA DC-8 during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ) field campaign. In 9 of the 12 analyzed plumes, dilution-normalized HCHO increases with physical age (range 1-6 h). The balance of HCHO loss (mainly via photolysis) and production (via OH-initiated VOC oxidation) seems to control the sign and magnitude of this trend. Plume-average OH concentrations, calculated from VOC decays, range from -0.5 (+/- 0.5) x 10(6) to 5.3 (+/- 0.7) x 10(6) cm(-3). The production and loss rates of dilution-normalized HCHO seem to decrease with plume age. Plume-to-plume variability in dilution-normalized secondary HCHO production correlates with OH abundance rather than normalized OH reactivity, suggesting that OH is the main driver of fire-to-fire variability in HCHO secondary production. Analysis suggests an effective HCHO yield of 0.33 (+/- 0.05) per VOC molecule oxidized for the 12 wildfire plumes. This finding can help connect space-based HCHO observations to the oxidizing capacity of the atmosphere and to VOC emissions. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. None eng geoscientificInformation