Processes influencing ozone levels in Alaskan forest fire plumes during long-range transport over the

[1] A case of long-range transport of a biomass burning plume from Alaska to Europe is analyzed using a Lagrangian approach. This plume was sampled several times in the free troposphere over North America, the North Atlantic and Europe by three different aircraft during the IGAC Lagrangian 2K4 experiment which was part of the ICARTT/ ITOP measurement intensive in summer 2004. Measurements in the plume showed enhanced values of CO, VOCs and NOy, mainly in form of PAN. Observed O-3 levels increased by 17 ppbv over 5 days. A photochemical trajectory model, CiTTyCAT, was used to examine processes responsible for the chemical evolution of the plume. The model was initialized with upwind data and compared with downwind measurements. The influence of high aerosol loading on photolysis rates in the plume was investigated using in situ aerosol measurements in the plume and lidar retrievals of optical depth as input into a photolysis code (Fast-J), run in the model. Significant impacts on photochemistry are found with a decrease of 18% in O-3 production and 24% in O-3 destruction over 5 days when including aerosols. The plume is found to be chemically active with large O-3 increases attributed primarily to PAN decomposition during descent of the plume toward Europe. The predicted O-3 changes are very dependent on temperature changes during transport and also on water vapor levels in the lower troposphere which can lead to O-3 destruction. Simulation of mixing/dilution was necessary to reproduce observed pollutant levels in the plume. Mixing was simulated using background concentrations from measurements in air masses in close proximity to the plume, and mixing timescales ( averaging 6.25 days) were derived from CO changes. Observed and simulated O-3/CO correlations in the plume were also compared in order to evaluate the photochemistry in the model. Observed slopes change from negative to positive over 5 days. This change, which can be attributed largely to photochemistry, is well reproduced by multiple model runs even if slope values are slightly underestimated suggesting a small underestimation in modeled photochemical O-3 production. The possible impact of this biomass burning plume on O-3 levels in the European boundary layer was also examined by running the model for a further 5 days and comparing with data collected at surface sites, such as Jungfraujoch, which showed small O-3 increases and elevated CO levels. The model predicts significant changes in O-3 over the entire 10 day period due to photochemistry but the signal is largely lost because of the effects of dilution. However, measurements in several other BB plumes over Europe show that O-3 impact of Alaskan fires can be potentially significant over Europe.

[1]  J. Logan,et al.  Effect of rising Asian emissions on surface ozone in the United States , 1999 .

[2]  Trainer,et al.  The influence of canadian forest fires on pollutant concentrations in the united states , 2000, Science.

[3]  F. Achard,et al.  Ecology: Human role in Russian wild fires , 2006, Nature.

[4]  H. Schlager,et al.  Long‐range transport and tropospheric ozone variability in the western Mediterranean region during the Intercontinental Transport of Ozone and Precursors (ITOP‐2004) campaign , 2007 .

[5]  A. Stohl,et al.  Perturbation of the European free troposphere aerosol by North American forest fire plumes during the ICARTT-ITOP experiment in summer 2004 , 2007 .

[6]  A. Volz-Thomas,et al.  On the budget of hydroxyl radicals at Schauinsland during the Schauinsland Ozone Precursor Experiment (SLOPE96) , 2000 .

[7]  D. Jacob,et al.  Impact of new laboratory studies of N2O5 hydrolysis on global model budgets of tropospheric nitrogen oxides, ozone, and OH , 2005, Geophysical Research Letters.

[8]  Costas A. Varotsos,et al.  In situ measurements of stratospheric ozone depletion rates in the Arctic winter 1991/1992: A Lagrangian approach , 1998 .

[9]  A. Stohl,et al.  Pan-Arctic enhancement of light absorbing aerosol concentration due to North American boreal forest fires during summer 2004 , 2006 .

[10]  W. Hao,et al.  Measurements of excess O3, CO2, CO, CH4, C2H4, C2H2, HCN, NO, NH3, HCOOH, CH3COOH, HCHO, and CH3OH in 1997 Alaskan biomass burning plumes by airborne Fourier transform infrared spectroscopy (AFTIR) , 2000 .

[11]  Joachim Reuder,et al.  Aerosol effects on UV radiation in nonurban regions , 1999 .

[12]  Andreas Richter,et al.  Forest fire plumes over the North Atlantic: p-TOMCAT model simulations with aircraft and satellite measurements from the ITOP/ICARTT campaign , 2007 .

[13]  D. Imre,et al.  Analysis of the processing of Nashville urban emissions on July 3 and July 18, 1995 , 2000 .

[14]  P. Crutzen,et al.  Biomass Burning in the Tropics: Impact on Atmospheric Chemistry and Biogeochemical Cycles , 1990, Science.

[15]  S. Bony,et al.  SIRTA, a ground-based atmospheric observatory for cloud and aerosol research , 2005 .

[16]  D. Blake,et al.  Impacts of biomass burning in Southeast Asia on ozone and reactive nitrogen over the western Pacific in spring , 2004 .

[17]  T. Eck,et al.  A review of biomass burning emissions part III: intensive optical properties of biomass burning particles , 2004 .

[18]  D. Jacob,et al.  Photochemistry in biomass burning plumes and implications for tropospheric ozone over the tropical South Atlantic , 1998 .

[19]  Philippe Keckhut,et al.  Improved retrievals of the optical properties of cirrus clouds by a combination of lidar methods. , 2005, Applied optics.

[20]  D. Jacob,et al.  Origin of tropospheric NO x over subarctic eastern Canada in summer , 1994 .

[21]  C. Sloane.  Optical properties of aerosols of mixed composition , 1984 .

[22]  A. Stohl.  A 1-year Lagrangian ``climatology'' of airstreams in the Northern Hemisphere troposphere and lowermost stratosphere , 2001 .

[23]  L. Mearns,et al.  Climate Change and Forest Fire Potential in Russian and Canadian Boreal Forests , 1998 .

[24]  Ulla Wandinger,et al.  Transport of boreal forest fire emissions from Canada , 2001 .

[25]  G. Carmichael,et al.  Impacts of biomass burning on tropospheric CO, NOx, and O3 , 2000 .

[26]  A. Stohl,et al.  Interpolation Errors in Wind Fields as a Function of Spatial and Temporal Resolution and Their Impact on Different Types of Kinematic Trajectories , 1995 .

[27]  R. Francey,et al.  Measurements of biomass burning influences in the troposphere over southeast Australia during the SAFARI 2000 dry season campaign , 2003 .

[28]  A. Stohl,et al.  Alaskan and Canadian forest fires exacerbate ozone pollution over Houston, Texas, on 19 and 20 July 2004 , 2006 .

[29]  Stuart A. Penkett,et al.  Photochemical trajectory modeling studies of the North Atlantic region during August 1993 , 1996 .

[30]  John Methven,et al.  Establishing Lagrangian Connections between Observations within Air Masses Crossing the Atlantic during the ICARTT Experiment , 2006 .

[31]  J. Pyle,et al.  Evaluation of a Lagrangian box model using field measurements from EASE (Eastern Atlantic Summer Experiment) 1996 , 2000 .

[32]  P. Crutzen,et al.  Acetone in the atmosphere: Distribution, sources, and sinks , 1994 .

[33]  A. Lacis,et al.  Aerosol retrievals over the ocean by use of channels 1 and 2 AVHRR data: sensitivity analysis and preliminary results. , 1999, Applied optics.

[34]  Oliver Wild,et al.  Fast-J: Accurate Simulation of In- and Below-Cloud Photolysis in Tropospheric Chemical Models , 2000 .

[35]  A. Goldstein,et al.  Transport of forest fire emissions from Alaska and the Yukon Territory to Nova Scotia during summer 2004 , 2007 .

[36]  D. Jacob,et al.  Inventory of boreal fire emissions for North America in 2004 : Importance of peat burning and pyroconvective injection , 2007 .

[37]  D. Blake,et al.  Influence of plumes from biomass burning on atmospheric chemistry over the equatorial and tropical South Atlantic during CITE 3 , 1994 .

[38]  Gerhard Wotawa,et al.  Ozone production from Canadian wildfires during June and July of 1995 , 2002 .

[39]  D. Jacob,et al.  Biomass‐burning emissions and associated haze layers over Amazonia , 1988 .

[40]  P. Pilewskie,et al.  Evolution of gases and particles from a savanna fire in South Africa , 2003 .

[41]  P. Hyde,et al.  Modeling of trace gases from the 1998 North Central Mexico forest fire smoke plume, as measured over Phoenix , 2006 .

[42]  G. Carmichael,et al.  Influences of biomass burning during the Transport and Chemical Evolution Over the Pacific (TRACE‐P) experiment identified by the regional chemical transport model , 2003 .

[43]  Mian Chin,et al.  Indonesian wildfires of 1997: Impact on tropospheric chemistry , 2003 .

[44]  P. Crutzen,et al.  Biomass burning as a source of atmospheric gases , 1979 .

[45]  Thomas Trautmann,et al.  Simulation of a biomass-burning plume: Comparison of model results with observations , 2002 .

[46]  Mike Fromm,et al.  A case study of pyro-convection using transport model and remote sensing data , 2006 .

[47]  D. Imre,et al.  Analysis of O3 formation during a stagnation episode in central Tennessee in summer 1995 , 2000 .

[48]  A. Stohl.  Computation, accuracy and applications of trajectories—A review and bibliography , 1998 .

[49]  M. Andreae,et al.  Chemical processes in a young biomass-burning plume , 2003 .

[50]  M. Wendisch,et al.  Optical closure for an aerosol column: Method, accuracy, and inferable properties applied to a biomass‐burning aerosol and its radiative forcing , 2002 .

[51]  M. Val Martin,et al.  Significant enhancements of nitrogen oxides, black carbon, and ozone in the North Atlantic lower free troposphere resulting from North American boreal wildfires , 2006 .

[52]  A. Stohl,et al.  Extreme CO concentrations in the upper troposphere over northeast Asia in June 2003 from the in situ MOZAIC aircraft data , 2005 .

[53]  A. Stohl,et al.  Pan‐Arctic enhancements of light absorbing aerosol concentrations due to North American boreal forest fires during summer 2004 , 2006 .

[54]  J. Levine.  Impact of Biomass Burning on Tropospheric CO and OH: A Two-Dimensional Study , 1991 .

[55]  P. Crutzen,et al.  Biomass burning as a source of atmospheric gases CO, H2, N2O, NO, CH3Cl and COS , 1979, Nature.

[56]  Paul B. Kebabian,et al.  The Arctic Boundary Layer Expedition (ABLE 3A): July–August 1988 , 1992 .

[57]  J. Lamarque,et al.  Quantifying CO emissions from the 2004 Alaskan wildfires using MOPITT CO data , 2005 .

[58]  J. Stith,et al.  Particle emissions and the production of ozone and nitrogen oxides from the burning of forest slash , 1981 .

[59]  Louisa Emmons,et al.  Ozone production from the 2004 North American boreal fires , 2006 .

[60]  Philip B. Russell,et al.  International Consortium for Atmospheric Research on Transport and Transformation (ICARTT): North America to Europe—Overview of the 2004 summer field study , 2006 .

[61]  Kathy S. Law,et al.  Establishing Lagrangian connections between observations within air masses crossing the Atlantic during the International Consortium for Atmospheric Research on Transport and Transformation experiment , 2006 .

[62]  M. Chipperfield,et al.  Statistical inference of OH concentrations and air mass dilution rates from successive observations of nonmethane hydrocarbons in single air masses , 2007 .

[63]  Hajime Akimoto,et al.  Intercontinental transport of ozone and its precursors in a three-dimensional global CTM , 2001 .