1. Troposphere Strastosphere D. H. Gas phase chemistry Scavenging processes Fossil fuel Emissions Biomass burning emissions Biogenic emissions Boundary layer mixing Solar radiation Aerosols Air-sea exchanges Long-range transport Stratosphere-Troposphere exchanges Heterogeneous Chemistry Ozone layer O3O3 NO 2 CO VOCs CH 4 SO 2 Dry deposition Aqueous phase chemistry Deep convection Erosion Aerosols

2. ORCHIDEE LMDz-INCA chemistry-climate model On-line chemistry model in LMDz Resolution: 3.75  long. x 1.9  (19-39 lev) NMHC gas phase chemistry (about 100 tracers) Different aerosol types (SO 4, BC, OC, Dust, Seasalt, Nitrates) Interactive dry deposition scheme Van-Leer (1977) advection; K. Emanuel convection; Louis (1972) boundary layer mixing (Hauglustaine et al., 2004) Dynamical global vegetation model: seasonal phenological cycle - carbon cycle, latent and sensible heat fluxes. Dynamical vegetation model (Krinner et al., 2004) Biogenic NMHC emission parameterization (LAI, PFT emissivities, temperature, PAR, leaf age, CO 2 ) (Lathière et al., 2006) NO and NH 3 soil emissions (soil temperature and moisture, precipitation pulses, fertilizers)

3. Use the LMDz-INCA model to simulate the impact of ozone precursors (NOx, NMHC) emissions on tropospheric ozone and associated radiative forcing of climate. The model has already been used in source-receptor studies in the framework of the HTAP/CLRTAP intercomparison simulations (2010). These simulations investigated the imapct of a 20% reduction in precursors emissions on ozone. These simulations will be done with the new ACCMIP/RCP emissions (for the present and if needed for the future) using a mask to investigate the impact of chinese emissions acting alone. Small perturbations of the emissions will be used and scaled up in order to avoid non- linearities in the response. The ozone perturbation fields will be used in the LMDz radiation code in order to calculate the radiatice forcing of climate.