edu.ucar.opensky::articles:24062 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-25T06:36:23.396570 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7g44tmc Emissions of reactive nitrogen from Western U.S. wildfires during summer 2018 2021-01-27T00:00:00Z publication https://n2t.org/ark:/85065/d7g44tmc https://doi.org/10.1029/2020JD032657 Lindaas, J. author Pollack, I. B. author Garofalo, L. A. author Pothier, M. A. author Farmer, D. K. author Kreidenweis, S. M. author Campos, Teresa author Flocke, Frank M. author Weinheimer, Andrew author Montzka, Denise D. author Tyndall, Geoffrey S. author Palm, B. B. author Peng, Q. author Thornton, J. A. author Permar, W. author Wielgasz, C. author Hu, L. author Ottmar, R. D. author Restaino, J. C. author Hudak, A. T. author Ku, I. author Zhou, Y. author Sive, B. C. author Sullivan, A. author Collett, J. L. author Fischer, E. V. author UCAR/NCAR - Library publisher Reactive nitrogen (N-r) within smoke plumes plays important roles in the production of ozone, the formation of secondary aerosols, and deposition of fixed N to ecosystems. The Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) field campaign sampled smoke from 23 wildfires throughout the western U.S. during summer 2018 using the NSF/NCAR C-130 research aircraft. We empirically estimate N-r normalized excess mixing ratios and emission factors from fires sampled within 80 min of estimated emission and explore variability in the dominant forms of N-r between these fires. We find that reduced N compounds comprise a majority (39%-80%; median = 66%) of total measured reactive nitrogen (Sigma N-r) emissions. The smoke plumes sampled during WE-CAN feature rapid chemical transformations after emission. As a result, within minutes after emission total measured oxidized nitrogen (Sigma NOy) and measured total Sigma NHx (NH3 + pNH(4)) are more robustly correlated with modified combustion efficiency (MCE) than NOx and NH3 by themselves. The ratio of Sigma NHx/Sigma NOy displays a negative relationship with MCE, consistent with previous studies. A positive relationship with total measured Sigma N-r suggests that both burn conditions and fuel N content/volatilization differences contribute to the observed variability in the distribution of reduced and oxidized N-r. Additionally, we compare our in situ field estimates of N-r EFs to previous lab and field studies. For similar fuel types, we find Sigma NHx EFs are of the same magnitude or larger than lab-based NH3 EF estimates, and Sigma NOy EFs are smaller than lab NOx EFs. 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 2021 American Geophysical Union. None eng geoscientificInformation