ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-10-9739-2010 Nitrogen oxides and PAN in plumes from boreal fires during ARCTAS-B and their impact on ozone: an integrated analysis of aircraft and satellite observations Alvarado M. J. 1 2 Logan J. A. 1 Mao J. 1 Apel E. 3 Riemer D. 4 Blake D. 5 Cohen R. C. 6 Min K.-E. 6 Perring A. E. 6 Browne E. C. 6 Wooldridge P. J. 6 Diskin G. S. 7 Sachse G. W. 7 Fuelberg H. 8 Sessions W. R. 8 Harrigan D. L. 8 Huey G. 9 Liao J. 9 Case-Hanks A. 9 Jimenez J. L. 10 Cubison M. J. 10 Vay S. A. 7 Weinheimer A. J. 3 Knapp D. J. 3 Montzka D. D. 3 Flocke F. M. 3 Pollack I. B. 3 Wennberg P. O. 11 Kurten A. 11 Crounse J. 11 Clair J. M. St. 11 Wisthaler A. 12 Mikoviny T. 12 Yantosca R. M. 1 Carouge C. C. 1 Le Sager P. 1 School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts, USA Now at Atmospheric and Environmental Research, Inc., Lexington, Massachusetts, USA Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, Colorado, USA Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA School of Physical Sciences, University of California, Irvine, California, USA Chemistry Department, University of California, Berkeley, California, USA NASA Langley Research Center, Hampton, Virginia, USA Department of Meteorology, Florida State University, Tallahassee, Florida, USA School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA. Department of Chemistry and Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, USA California Institute of Technology, Pasadena, California, USA Institut für Ionenphysik & Angewandte Physik, University of Innsbruck, Innsbruck, Austria 18 10 2010 10 20 9739 9760 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/10/9739/2010/acp-10-9739-2010.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/10/9739/2010/acp-10-9739-2010.pdf

We determine enhancement ratios for NO<sub>x</sub>, PAN, and other NO<sub>y</sub> species from boreal biomass burning using aircraft data obtained during the ARCTAS-B campaign and examine the impact of these emissions on tropospheric ozone in the Arctic. We find an initial emission factor for NO<sub>x</sub> of 1.06 g NO per kg dry matter (DM) burned, much lower than previous observations of boreal plumes, and also one third the value recommended for extratropical fires. Our analysis provides the first observational confirmation of rapid PAN formation in a boreal smoke plume, with 40% of the initial NO<sub>x</sub> emissions being converted to PAN in the first few hours after emission. We find little clear evidence for ozone formation in the boreal smoke plumes during ARCTAS-B in either aircraft or satellite observations, or in model simulations. Only a third of the smoke plumes observed by the NASA DC8 showed a correlation between ozone and CO, and ozone was depleted in the plumes as often as it was enhanced. Special observations from the Tropospheric Emission Spectrometer (TES) also show little evidence for enhanced ozone in boreal smoke plumes between 15 June and 15 July 2008. Of the 22 plumes observed by TES, only 4 showed ozone increasing within the smoke plumes, and even in those cases it was unclear that the increase was caused by fire emissions. Using the GEOS-Chem atmospheric chemistry model, we show that boreal fires during ARCTAS-B had little impact on the median ozone profile measured over Canada, and had little impact on ozone within the smoke plumes observed by TES.

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