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List of Abstracts 219and particulate matter in the area. This analysis has been carried out by a combination of back-trajectorycalculations and observations of correlations among trace gases as well as chemical and elementalcomponents of aerosol. Among the findings are that SO2 concentrations generally show a geographicaldistribution similar to that of tracers of heavy fuel combustion, typical of ship ship emissions. High ozoneconcentrations are found to be strongly related to breeze circulation and subsiding air masses.P-Observations 2.102 ID:4547 10:30A comparison of wind tunnel measurements and CFD model simulations for pollutant dispersion froma tunnel portal for different wind directionsSeyed Mohammad Taghavi 1 , Bertrand Carissimo 1 , Fredrique Gourdol 2 , Patrick Mejean 2 , LionelSoulhac 2 , Cyrille Bernagaud 3 , Jean Francois Burkhart 31 Centre d’Enseignement et de Recherche sur l’Environnement Atmosphérique (CEREA), Paris, France2 Ecole Central de Lyon, Lyon, France3 Ministère de l'Ecologie, de l'Energie, du Développement Durable et de la Mer, Centre d'Etudes des TuContact: taghavi@cerea.enpc.frThe exhausts from tunnel heads in urban area may be considered as important local air pollutant emissionsource due to the concentrated release of polluted air, which can affect air quality in its vicinity. Hence, it isimportant to have suitable tools to assess the dispersion from roadway tunnels for planning purposes.Mercure_Saturne, a three-dimensional computational fluid dynamics (CFD) model developed at CEREA andnow part of the open source software (www.code-saturne.org), was applied to simulate pollutants dispersionof an experimental study which had been performed on a model tunnel in the atmospheric boundary layerwind tunnel of the Laboratoire de Mécanique des Fluides et d’Acoustique (LMFA), France. The k-epsturbulence closure was applied. A total of 28 configurations for 7 wind directions relative to the tunnel axis(0, 30, 60, 90, 120, 150, 180°) and 4 different velocity ratio between the tunnel exit velocity and the windvelocity (0.25, 1, 2 and 4) were simulated. Only one grid with the tunnel geometry was generated and thewind direction is varied on the boundaries. Measurements of wind, turbulence and concentration are used forthe comparison. First we have performed detailed comparison of the profiles, especially for concentrationsbut also for wind and turbulence which help in the interpretation of the results. Sensitivity analyses areperformed for the turbulence conditions at the tunnel head due to incomplete measurements (no epsilon). Inaddition to these point wise comparisons we have also computed statistical parameters to characterize thedifferences between measurements and simulations by following the Model validation kit procedures. Wediscuss these different statistics for all the cases simulated and for the different tunnel exit conditions usedfor the sensitivity analysis.P-Observations 2.103 ID:4344 10:30Observed and Modeled Variations of Tropospheric Molecular Hydrogen over JapanHisashi Yashiro 1 , Masayuki Takigawa 1 , Kengo Sudo 2 , Satoshi Sugawara 3 , Shuji Aoki 4 , TakakiyoNakazawa 41 Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology2 Graduate School of Environmental Studies, Nagoya University3 Institute of Earth Science, Miyagi University of Education4 Center for Atmospheric and Oceanic Studies, Graduate School of Science, Tohoku UniversityContact: h.yashiro@jamstec.go.jpTo elucidate temporal and spatial variations of tropospheric molecular hydrogen (H2), air samples weresystematically collected once per month using a chartered light aircraft (0~4km) and commercial jet airliners(4~11km). Their H2 concentrations were determined against our gravimetrically prepared standard gasesiCACGP-IGAC 2010 14 July, 2010