Summary on Prague workshop

1. Summary on Prague workshop dimitri.caro@cea.fr LSCE, CNRS/CEA, Gif sur Yvette, France QUANTIFY Workshop, De Bilt, 8-9 november 2005

2. ACTIVITY 2 WP 2.1.1 Road traffic CERC, IVL, NIMH WP 2.1.2 Ship plumes (small scale) IVL, CERFACS WP 2.1.3 Ship plumes (meso scale) IVL, CUNI, NIMH WP 2.2.1 Aircraft wakes (small scale) IVL, ONERA WP 2.2.2 Aircraft wakes (meso scale) CERFACS WP 2.3 Ship measurement DLR,UYO,PSI,HA,CUNI WP 2.4 Effective emission indices CERFACS,CERC,NMA,NIMH, CUNI

3. Aircraft plumes (small and meso scales) WP 2.2.1, 2.2.2, 2.4 CERFACS: Roberto.Paoli@cerfacs.fr CERFACS: Benedicte.Cuenot@cerfacs.fr Intensive review of modeling and computational methods for Effective Emission Indices Review paper submitted before the end of the year: Paoli, Caro, Meijer and Sausen definition of chemistry and aerosol chemistry schemes for new plume simulations comparison with 10 plume measurements already available (Hans Schlager) simulations for the lowermost stratosphere with Br and Cl chemistry consideration of effect of plume processes by a modification of reaction rates (CERFACS)

4. plume NOx ambient + NOx emissions NOx(t) NOx(t=0) plume NOx ambient Parameterizations of aircraft plumes Approach of Kraabol et al. (2000, 2002) and Meijer (2001): Emission Conversion Factors 15h 0 t 18h Approach of Petry et al. (1998): Effective Emission Indices grid box NOx(t=0)+NOx(t=0) boxNOx(t) = NOx(t=0) plumeNOx(t) plume NOx ambient + NOx emissions  Plumb et al. (2003): Comparison of the two approaches ?

5. GCM results including aircraft plume processes Disagreement for O3 results between Kraabol et al. et Meijer ? Plumb et al. (2003): - similar results with the two plume parameterizations - small impact of plume processes on O3 as in Meijer (2001) Shortcomings of these results: - consideration of one plume for the total emissions of a grid box ! - no interaction of plumes  overestimation of the plume effects on NOx and O3

6. Parameters controlling the chemical conversion of aircraft emissions in a dispersing plume - : negligeable effect (<< 10%) ± : moderate effect (~ 10%) + : strong effect (>> 10%) K : Kraabol et al. (2000, 2002), M : Meijer (2001), Pe : Petry et al. (1998), Pl : Plumb et al. (2003) Dynamical variables for dispersion of plumes :  Diffusion coefficients (M -)  Wind shear (M ±,Pl ±) Composition of background atmosphere :  air masses (Pl +)  clean air vs corridor conditions (K +, Pe +)  NOx and O3 background conditions (K +, M +) Location of emissions :  Latitude (K +, M +, Pl +)  Altitude (M +, Pl +) Heterogeneous chemistry (K -, M -) Type of aircraft (K ±, M ±) Calculations of ECFs or EEIs Meteorological parameters :  T (K +, M ±)  Humidity (M +)  Photolysis (K ±, M ±) Time of year of emissions :  Months (K +, M +, Pl +)  Seasons (K +, M +, Pl +) Emission time (K +, M +, Pe +, Pl -) Plume models : single or multishell plume (K +, Pe -) A lot of parameters, a lot of uncertainties compared to a possibly small impact !  Plumb et al. (2003): importance of emission time depends on the end time of the plume  need for a precise definition of end time of the plume  relation between end time of plume and grid box resolution ?

7. Ship plumes (small and meso scales) WP 2.1.2, 2.1.3, 2.3, 2.4 CERFACS: Roberto.Paoli@cerfacs.fr DLR: hans.schlager@dlr.de • Measurement pre-campaign in July 2006 and campaign in spring 2007 • Need to define the parameter fields that should be measured for a global modelling • necessity for pre-simulations of ship plume processes with a detailed plume model to identify the essential parameters • Need for the development of ship plume simulations • importance of sea wake for initial NOx emissions through humidification of air wake (plume)

8. Modeling the chemical effects of ship exhausts Glasow et al. (2002)  Box model: plume and background reservoirs  Dilution of plume: expansion of the plume + entrainment of background air  Expansion of the single plume: Constant parameters (≠gaussian plume)  Mixing of concentrations:  Chemical lifetime of the ship plume: 2 days  Effects of emissions of several ships and plume overlap: - Calculations of an «average ship» emission and a «ship density» - Homogeneous distribution of ships and all ship routes parallel - Specific aera : 1730 x 1730 km (length of plume after 2 days)  Plume overlap if more than 40 ships  mean time lag between 2 ships  interaction between 2 plumes  Background/background+plume comparison: - Important increase in NOx and SO2 - Negligeable impact on O3  Expanding plume (EP)/instantaneous dispersion (ID) comparison: - Twice less with the EP for O3, OH, NOx, SO2 Disagreement still exists between these calculations and the measurements ! Lot of uncertainties in the estimate of ship emissions Lot of uncertainties regarding this averaging approach

9. Surface transport emission WP 2.1.1, 2.4 Stéphanie Gray (CERC): steph@cerc.co.uk • review paper on emission data from road traffic partly done (draft available from CERC) • estimation of emissions, availability of emission data, evolution of emissions in the atmosphere • modelling with IVL (for heterogeneous processes) and NIMH (for mesoscale modelling) • Required work: - investigation to understand which processes are important for the dispersion of road traffic emissions onto scale of climate models - small-scale output from ADMS-Urban (CERC) to be used as input to larger scale modelling • preliminary modelling: study of effect of modelling road traffic emissions on different scales • future work: further preliminary modelling, improvement of chemistry, selection of modelling • configurations for mesoscale models