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This is the first study that quantifies the impact of wildfires in the highly radioactive forests of Ukraine, Belarus and Russia on the human population and the environment. Since the Chernobyl accident in 1986, extreme contamination of forests in Ukraine, Belarus and Russia resulted in evacuation and lack of forest management. Currently, trees cover more than 70% of these areas, and Climate Change suggests increasing fire risks. These worrying findings call on the scientific community and the European responsible authorities to study the consequences of wildfire scenarios and quantify the health risks for humans and animals. The global aerosol model LMDZORINCA was used to predict the 4D distribution of 137Cs following the fire scenarios at a resolution of 0.66°×0.51° (zoom centered over Europe) over 19 vertical layers. The spatial deposition density of 137Cs (Bq m-2) in these forests is currently well known either from measurement or modelling and is multiplied by the burnt area (m2) read from MODIS to estimate 137Cs emissions. We estimate that up to 4.5 PBq of 137Cs can migrate over Europe, which constitutes a serious accident in the International Nuclear Events Scale (INES). A number between 20 and 240 may suffer from solid cancers in Europe, of which 10 – 170 may be fatal. This is very important if one takes into account that the global excess lifetime fatalities from the recent accident in Japan have been estimated to be between 220 to 520. Increased radiation levels have changed the animal population regime in the area since 1986. The situation near these forests will be exacerbated after a major fire, due to the Chernobyl-remaining refractory elements (such as Pu and Am), also trapped there.

Description: Global death (or mortality) risk from radiation cancer estimated after the Fukushima accident in Japan (2011). Risks were calculated by combining relative risks and functions of the Linear No-Threshold (LNT) model with the results of the LMDZORINCA simulations for the accident. Two of the most important radionuclides, that constitute the global fallout, have been examined (134Cs and 137Cs). The resolution of the model version used here is 2.5ox1.3o over 39 vertical levels. Our results showed that 360 - 850 cancer incidents are expected, of which 220 - 520 may be fatal. This is the first reported map that localizes cancer risk after Fukushima, whereas comparisons with other estimation (e.g. Ten Hoeve and Jacobson, 2012) show excellent coherence of our results.

Atmospheric emission and transport of 137Cs after the major fires of 2002 inside Chernobyl's Exlcusion Zone and Belarusian forests as seen from the LMDZORINCA model. The resolution of the present version is 0.66ox0.51o over 19 vertical levels. Animation shows the 3-D representation of the iso-surface of 137Cs for activity concentrations between 0 and 1 Bq/m3.

Simulation of the worldwide transport of 137Cs after the Fukushima Daiich Nuclear Power Plant accident in Japan as a result of the earthquake and the tsunamis' attack (March 11th, 2011). Three-dimensional representation of the iso-surface of 137Cs (0.8 mBq m-3 STP). On the left panel the simulation of 144x142 configuration over 19 levels is depicted, whereas in the right one the same simulation over 39 vertical levels. Red denotes increased activity concentrations, whereas green lower ones (range of the iso-surface 0-1.6 mBq m-3 STP). The activity concentrations are expressed in Bq per m3 STP, where m3 STP is a standard cubic meter of air at 273.15 oK temperature and 1 atm pressure.

Relative contribution (%) of aircraft (blue), shipping (yellow), and road (red) emissions to boundary layer ozone increase due to transport in Europe and in the United States in 2050 under business as usual scenario A1B (left) and the mitigation scenario B1 ACARE (right). The ozone change is integrated from the ground level to the pressure of 910 hPa (lowest three model levels). Hauglustaine and Khoffi (2012).

Model simulations, climatologies, and integrated products
Simulated 4D European and global climatologies of reactive gases and aerosol fields are available at (http://www.geomon.eu/science/act5/SciAct5_MOD_WP2.html). They concern both stratospheric and tropospheric contents. Two of these climatologies are obtained from model ensemble simulations (from the RETRO and AEROCOM projects). The Air Quality climatology for O3 and aerosols was provided by INERIS based on the Prev'air system combining CHIMERE model results and surface observations.
Comparisons between CARIBIC measurements and LMDz-INCA simulations of acetone concentrations are on-going. Measurements acquired onboard a commercial airplane in the framework of the CARIBIC Project (http://www.caribic-atmospheric.com/) are superimposed to simulated daily means, generated with the global CTM LMDz-INCA running at a 3.75°x2.5° horizontal resolution (http://lmdz.lmd.jussieu.fr/applications/projets/inca, http://www-lsceinca.cea.fr/) in Figure 1.
The selected flight is made from Santiago De Chile (Chile) to Frankfurt (Germany), via Sao Paulo (Brazil) on 21 March 2006. Around 15°N, the airplane crosses a plume of acetone extending from northern South America to Africa. Figure 2, based on instantaneous simulated results interpolated online to the flightracks, shows a good agreement between measurements and simulations. In particular the plume where acetone concentration reaches 700 ppt between 10 and 20°N is reproduced (Figures 2a and 2b), as well as the concentration level of around 500 ppt on eastern South America in the flight to Sao Paulo (Figure 2a), and the change of acetone concentration of more than 100 ppt over the North Atlantic Ocean (for latitude larger than 20°) during the flight back (Figure 2b).
This work will be pursued by sensitivity tests of LMDz-INCA to sources and sinks in order to improve the agreement of modelling with observation and extended to CO and CH4 comparions with the TM5 model.
contacts: T. Elias (thierry.eliaslsce.ipsl.fr) & S. Szopa (sophie.szopalsce.ipsl.fr)

Zonal mean CH3OH volume mixing ratio profiles observed by the ACE-FTS (left) and simulated with the LMDz-INCA model (right) for each season from March 2004 to August 2005. The modeled profiles used are interpolated at the measurement locations. The number of profiles averaged in each 20° latitude band is indicated on the left panels (white squares). Only averages with more than 10 profiles are displayed. A mean tropopause height is calculated based on NCEP meteorological fields for each measured methanol profile and from the model for the calculated distributions (white line).
Dufour et al., ACP, 2007

The dust forecast performed daily with the experimental INCA chemical weather forecast is compared to the Aeronet sun photometer measurements in Dakar,M'Bour,Africa (acknowledgement Didier Tanre LOA). The analysis of the initialisation day (J0) and of the forecast +2 days (J2) and +5 days (J5) is compared to the 2006 annual cycle of aerosol optical depth. Despite a degradation of the AOD forecast with increasing time forecasted the global model can reproduce the general characteristics of the dust appearance at the borders of the Sahara.

Individual contributions of the five aerosol components (SS-seasalt, DU-dust, POMparticulate organic matter, BC-black carbon, SU-sulfate) to the annual global aerosol optical thickness at 550nm (AOD) from different AeroCom models as compared to Aeronet (Ae) sun photometer and a satellite composite (S*) observations (From Kinne et al. 2006). LS represents the INCA model simulation. The models have quite a different understanding of how to derive global AOD from aerosol components. The just published AeroCom papers Kinne et al. ACP, 2006 and Textor et al. ACP, 2006 document considerable diversity in global aerosol models and the need to further improve aerosol parameterizations.

Monthly mean surface O3 changes in July 2030 (compared with July 2001) (a) at the global scale using LMDzINCA, for the "current legislation" scenario; (b)(c)(d) over Europe using the regional CTM CHIMERE forced with LMDzINCA boundary conditions, for, respectively, the "current legislation" scenario, the "maximum feasible reductions" scenario and the SRES-A2 scenario. (Sophie Szopa et al., GRL submitted in January)

A first simulation of the Antarctic ozone hole formation with the 50 level version of the coupled chemistry-climate model LMDz-INCA including the stratospheric gas phase and heterogeneous chemistry. The figure shows the onset of the polar vortex and the formation of the ozone hole for 1990 Cl and Br conditions. A maximum ozone destruction with total ozone column as low as 150-175 DU is reached in mid-october October. The dilution of the ozone hole appears in November-December. (Contact: D. Hauglustaine, LSCE).

Horizontal distribution of the annual mean in situ CO2 production rate for (left) the CO channel and (right) the radicals and ozonolysis channel. (top) Column integrated production rates (10**-9 TgC km**-2 yr**-1); (bottom) annual mean production rates at the surface (10**5 molecules cm**-3 yr**-1). Results are taken from the lowermost model level representing a layer height of approximately 140 meters. (see full description in G. Folberth, D. A. Hauglustaine, P. Ciais, and J. Lathière, On the role of atmospheric chemistry in the gloabl CO2 budget, 2005)

Annual global OH anomalies from mean inversion (solid line) compared with estimates from Prinn et al. (2001) (a) and from Krol et al. (2003) (b). Grey zone is the envelope of all 16 inversions. (see full description in P. Bousquet, D. A. Hauglustaine, P. Peylin, C. Carouge, and P. Ciais, Two decades of OH variability as inferred by an inversion of atmospheric transport and chemistry of methyl chloroform, 2005)