HR: 0800h
AN: A21B-0861    [Abstracts]
TI: Processes Influencing Ozone Levels in Forest Fire Plumes During Long-Range Transport Across the North Atlantic
AU: * Real, E
EM: elsa.real@aero.jussieu.fr
AF: Service d'Aeronomie/CNRS, 4, place Jussieu, Paris, 75252 France
AU: Law, K
A21B-0861 AF: Service d'Aeronomie/CNRS, 4, place Jussieu, Paris, 75252 France
AU: Ancellet, G
A21B-0861 AF: Service d'Aeronomie/CNRS, 4, place Jussieu, Paris, 75252 France
AU: Schlager, H
A21B-0861 AF: Inst. Atmos. Physics, DLR Oberpfaffenhofen, Wessling, D-82230 Germany
AU: Huntrieser, H
A21B-0861 AF: Inst. Atmos. Physics, DLR Oberpfaffenhofen, Wessling, D-82230 Germany
AU: Petzold, A
A21B-0861 AF: Inst. Atmos. Physics, DLR Oberpfaffenhofen, Wessling, D-82230 Germany
AU: Stohl, A
A21B-0861 AF: NILU, Instituttveien 18, Kjeller, N-2027 Norway
AU: Methven, J
A21B-0861 AF: Dept. Meteorology, University Reading, Reading, RG6 6BB United Kingdom
AU: Arnold, S
A21B-0861 AF: School of Earth and Environment, University of Leeds, Leeds, LS2 9JT United Kingdom
AU: Lewis, A
A21B-0861 AF: Dept. Chemistry, University of York, York, YO10 5DD United Kingdom
AU: Crawford, J
A21B-0861 AF: NASA Langley Research Center, MS-483, Hampton, VA 23681 United States
AU: Nedelec, P
A21B-0861 AF: Laboratoire d'Aerologie, 14, ave Edouard Belin, Toulouse, 31400 France
AU: Haeffelin, M
A21B-0861 AF: SIRTA, LMD/IPSL, Palaiseau, 91128 France
AB: In summer 2004, plumes from intense forest fires over Alaska and Canada were observed during the IGAC Lagrangian 2K4/ European ITOP (Intercontinental Transport of Ozone and Precursors) campaign. Lagrangian analysis using trajectory based tools showed that forest fires plumes were sampled several time by different platforms over the North Atlantic and Europe. These plumes were characterised by high levels of CO, VOC, PAN, forest fires aerosols and large increases in ozone levels between data collected over western Atlantic and Europe. A Lagrangian photochemical model CiTTyCAT was used to assess the influence of different processes on ozone levels in one of these plumes. The model was initialised with chemical data from the upwind sampled air mass, run along appropriate trajectories and then compared to chemical data downwind. The impact of forest fires aerosols on photolysis rates has been included in the model for this study. Ozone increases during transport are partly explained by large photochemical production in the plume due to the dissociation of PAN as a result of increasing the temperature during subsidence of the air masses over Europe. The analysis also shows that other processes played a key role especially mixing of the plume with other air masses. Upwind data have been used to identify and constrain air masses transported in close proximity to the plume and the effects of mixing on plume composition and chemistry was examined. Comparison of this simulation with results from a global model also helps to understand the role of mixing. Finally, possible import of pollutants from this forest fire plume into the European boundary layer has been investigated.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005