ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-11-465-2011 Californian forest fire plumes over Southwestern British Columbia: lidar, sunphotometry, and mountaintop chemistry observations McKendry I. 1 Strawbridge K. 2 Karumudi M. L. 3 O'Neill N. 3 Macdonald A. M. 4 Leaitch R. 4 Jaffe D. 5 Cottle P. 1 Sharma S. 4 Sheridan P. 6 Ogren J. 6 Department of Geography, the University of British Columbia, Vancouver, British Columbia, Canada Science and Technology Branch, Environment Canada, Centre for Atmospheric Research Experiments, Egbert, Ontario, Canada Université de Sherbrooke, Sherbrooke, QC, Canada Science and Technology Branch, Environment Canada, 4905 Dufferin Street, Toronto, Ontario M3H 5T4, Canada Atmospheric and Environmental Chemistry, University of Washington-Bothell, Seattle, USA NOAA-Earth System Research Laboratory, Global Monitoring Division, Boulder, Colorado, USA 17 01 2011 11 2 465 477 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/11/465/2011/acp-11-465-2011.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/11/465/2011/acp-11-465-2011.pdf

Forest fires in Northern California and Oregon were responsible for two significant regional scale aerosol transport events observed in southern British Columbia during summer 2008. A combination of ground based (CORALNet) and satellite (CALIPSO) lidar, sunphotometry and high altitude chemistry observations permitted unprecedented characterization of forest fire plume height and mixing as well as description of optical properties and physicochemistry of the aerosol. In southwestern BC, lidar observations show the smoke to be mixed through a layer extending to 5–6 km a.g.l. where the aerosol was confined by an elevated inversion in both cases. Depolarization ratios for a trans-Pacific dust event (providing a basis for comparison) and the two smoke events were consistent with observations of dust and smoke events elsewhere and permit discrimination of aerosol events in the region. Based on sunphotometry, the Aerosol Optical Thicknesses (AOT) reached maxima of ~0.7 and ~0.4 for the two events respectively. Dubovik-retrieval values of <i>r</i><sub>eff, f</sub> during both the June/July and August events varied between about 0.13 and 0.15 μm and confirm the dominance of accumulation mode size particles in the forest fire plumes. Both Whistler Peak and Mount Bachelor Observatory data show that smoke events are accompanied by elevated CO and O<sub>3</sub> concentrations as well as elevated K<sup>+</sup>/SO<sub>4</sub> ratios. In addition to documenting the meteorology and physic-chemical characteristics of two regional scale biomass burning plumes, this study demonstrates the positive analytical synergies arising from the suite of measurements now in place in the Pacific Northwest, and complemented by satellite borne instruments.

 References Amiridis, V., Balis, D. S., Giannakaki, E., Stohl, A., Kazadzis, S., Koukouli, M. E., and Zanis, P.: Optical characteristics of biomass burning aerosols over Southeastern Europe determined from UV-Raman lidar measurements, Atmos. Chem. Phys., 9, 2431–2440, doi:10.5194/acp-9-2431-2009, 2009. Anderson, T. L. and Ogren, J.A.: Determining aerosol radiative properties using the TSI 3563 integrating nephelometer, Aerosol Sci. Tech., 29, 57–69, 1998. Bond, T. C.,~ Anderson, T. L. and Campbell, D.: Calibration and Intercomparison of Filter-Based Measurements of Visible Light Absorption by Aerosols, Aerosol Sci. Technol., 30, 582–600, 1999. Dubovik, O. and King, M. D.: A flexible inversion algorithm for retrieval of aerosol optical properties from Sun and sky radiance measurements, J. Geophys. Res., 105, 20673–20696, 2000. Duck, T. J., Firanski, B. J., Millet, D. B., Goldstein, A. H., Allan, J., Holzinger, R., Worsnop, D. R., White, A. B., Stohl, A., Dickinson, C. S., and van Donkelaar, A.: Transport of forest fire emissions from Alaska and the Yukon Territory to Nova Scotia during summer 2004, J. Geophys. Res.-Atmos., 112, D10S44, doi:10.1029/2006JD007716, 2007. Eck, T. F., Holben, B. N., Hyer, E. J., Reid, J. S., Shaw, G. E., Sinyuk, A., Vande Castle, J. R., Chapin, F. S., O'Neill, N. T., Dubovik, O., Smirnov, A., Vermote, E., Schafer, J. S., Giles, Slutsker, I., Sorokine, M., and Newcomb, W.: Optical Properties of Boreal Region Biomass Burning Aerosols In Alaska and Transport of Smoke to Arctic Regions, J. Geophys. Res., 114, D11201, doi:10.1029/2008JD010870, 2009. Hacker, J. P., McKendry, I.G., and Stull, R.B.: Modeled downward transport of Asian dust over Western North America during April 1998, J. Appl. Met., 40, 1617-1628, 2001. Hoff, R.M., Torres, O., Delgado R., and Rogers, R.: Lidar validation of Calipso and OMI using ground-based sensors from Realm. Third Symposium on LIDAR atmospheric Applications, The 87th AMS Annual Meeting (San Antonio, TX) 13–18 January, 2007. Holzer, M., McKendry, I.G., and Jaffe, D. A.: Springtime Trans-Pacific atmospheric transport from East Asia: A transit-time-PDF approach, J. Geophys. Res., 108(D22), 4708, doi:10.1029/2003JD003558, 2003. Jaffe, D., McKendry, I., Anderson, T., and Price, H.: Six `New' Episodes of Trans-Pacific Transport of Air Pollutants, Atmos. Environ., 37(3), 391–404, 2003. Leaitch, W. R., Macdonald, A. M., Anlauf, K. G., Liu, P. S. K., Toom-Sauntry, D., Li, S.-M., Liggio, J., Hayden, K., Wasey, M. A., Russell, L. M., Takahama, S., Liu, S., van Donkelaar, A., Duck, T., Martin, R. V., Zhang, Q., Sun, Y., McKendry, I., Shantz, N. C., and Cubison, M.: Evidence for Asian dust effects from aerosol plume measurements during INTEX-B 2006 near Whistler, BC, Atmos. Chem. Phys., 9, 3523–3546, doi:10.5194/acp-9-3523-2009, 2009. Kahn, R. A., Chen, Y., Nelson, D. L., Leung, F-Y, Li, Q., Diner, D. J., and Logan, J.A.: Wildfire smoke injection heights: Two perspectives from space, Geophys. Res. Lett., 35, L04809, doi:10.1029/2007GL032165, 2008. Kittaka, C., Pierce, B., Schaack, T., Al-Saadi, J., Soja, A., Tripoli, G., da Silva, A., Szykman, J., Lambeth, B. and Winker, D.: Synthesis of multiple observations using a regional aerosol assimilation/forecast model (RAQMS) and assessment of biomass burning emission estimates, 16th Annual International Emission Inventory Conference Emission Inventories: "Integration, Analysis, and Communications", available at: http://www.epa.gov/ttn/chief/conference/ei16/index.html#ses-10, Raleigh, May 14–17, 2007. McKendry, I. G., Hacker, J. P., Stull, R., Sakiyama, S., Mignacca, D., and Reid, K.: Long range transport of Asian dust to the Lower Fraser Valley, British Columbia, Canada, J. Geophys. Res., 106(D16), 18361–18370, 2001. McKendry, I.G., Strawbridge, K. O'Neill, N., Macdonald, A.M., Liu, P., Leaitch, W.R., Anlauf, K., Jaegle, L., Jaffe, D., Fairlie, D., and Westphal, D.: A Case of Trans-Pacific Transport of Saharan Dust to Western North America, J. Geophys. Res. 112, D01103, doi:10.1029/2006JD007129, 2007. McKendry, I. G., Macdonald, A. M., Leaitch, W. R., van Donkelaar, A., Zhang, Q., Duck, T., and Martin, R. V.: Trans-Pacific dust events observed at Whistler, British Columbia during INTEX-B, Atmos. Chem. Phys., 8, 6297–6307, doi:10.5194/acp-8-6297-2008, 2008. Murayama, T., Müller, D., Wada, K., Shimizu, A., Sekiguchi M., and Tsukamoto, T.: Characterisation of Asian dust and Siberian smoke with multi-wavelength Raman lidar over Tokyo, Japan in spring 2003, Geophys. Res. Lett., 31, L23103, doi:10.29/2004GL021105, 2004. O'Neill, N. T., Eck, T. F., Smirnov, A., Holben, B. N., and Thulasiraman, S.: Spectral discrimination of coarse and fine mode optical depth, J. Geophys. Res., 108(D17), 4559–4573, doi:10.1029/2002JD002975, 2003. O'Neill, N. T., Thulasiraman, S., Eck, T. F., and Reid, J. S.: Robust optical features of fine mode size distributions; application to the Québec smoke event of 2002, J. Geophys. Res., 110(D11), D11207, doi:10.1029/2004JD005414, 2005. O'Neill, N. T., Pancrati, O., Baibakov, K., Eloranta, E., Batchelor, R. L., Freemantle, J., McArthur, L. J. B., Strong, K., and Lindenmaier, R.: Occurrence of weak, sub-micron, tropospheric aerosol events at high Arctic latitudes, Geophys. Res. Lett., 35, L14814, doi:10.1029/2008GL033733, 2008. Pahlow, M., Kleissl, J., Parlange, M. B., Ondov, J. O., and Harrison, D.: Atmospheric boundary-layer structure observed during a haze event due to forest-fire smoke, Bound.-Lay. Meteorol., 114, 53–70, 2005. Reid, J. S., Eck, T. F., Christopher, S. A., Koppmann, R., Dubovik, O., Eleuterio, D. P., Holben, B. N., Reid, E. A., and Zhang, J.: A review of biomass burning emissions part III: intensive optical properties of biomass burning particles, Atmos. Chem. Phys., 5, 827–849, doi:10.5194/acp-5-827-2005, 2005a. Reid, J. S., Koppmann, R., Eck, T. F., and Eleuterio, D. P.: A review of biomass burning emissions part II: intensive physical properties of biomass burning particles, Atmos. Chem. Phys., 5, 799–825, doi:10.5194/acp-5-799-2005, 2005b. Sakai, T., Nagai, T., Nakazato, M., Mano, Y., and Matsumura, T.: Ice Clouds and Asian Dust Studied with Lidar Measurements of Particle Extinction-to-Backscatter Ratio, Particle Depolarization, and Water-Vapor Mixing Ratio over Tsukuba, Appl. Optics, 42, 7103–7116, 2003. Sassen, K.: Lidar Backscatter Depolarization Technique for Cloud and Aerosol Research, in: "Light Scattering by Nonspherical Particles: Theory, Measurements, and Geophysical Applications", edited by: Mishchenko, M. L., Hovenier, J. W., and Travis, L. D., Academic Press, ISBN0-12-498660-9, 393–416, 2000. Thulasiraman, S., O'Neill, N. T., Royer, A., Holben, B. N., Westphal, D. L., and McArthur, L. J. B.: Sunphotometric observations of the 2001 Asian dust storm over Canada and the US, Geophys. Res. Lett., 29(8), 1255–1258, doi:10.1029/2001GL014188, 2002. Vaughan, M. A., Powell, K. A., Winker, D. M., Hostetler, C. A., Kuehn, R. E., Hunt, W. H., Getzewich, B. J., Young, S. A., Liu, Z., and McGill, M. J.: Fully Automated Detection of Cloud and Aerosol Layers in the CALIPSO Lidar Measurements, J. Atmos. Ocean. Technol., 26(10), 2034–2050, 2009. Weiss-Penzias, P., Jaffe, D., Swartzendruber, P. Hafner, W., Chand, D., and Prestbo, E.: Quantifying atmospheric mercury emissions from biomass burning and East Asian industrial regions based on ratios with carbon monoxide in pollution plumes at the Mount Bachelor Observatory, Atmos. Environ., 41, 4366-4379, doi:10.1016/j.atmosenv.2007.1001.1058, 2007.