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Chemical assimilation and forecasts with the multiscale CTM MOCAGE.
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Chemical assimilation and forecasts with themultiscale CTM MOCAGE Vincent-Henri.Peuch@meteo.fr 1, J.-L. Attié 2, J.-P. Cammas 2, A. Dufour 1, B. Josse 1, F. Karcher 1, S. Massart 3, M. Michou 1, T. Morel3, P. Nédélec 2, S. Pradier 2, P. Simon 1, H. Teyssèdre 1 and D. Cariolle 3 • Météo-France, Centre National de Recherches Météorologiques • Laboratoire d’Aérologie, CNRS-UPS, Toulouse • CERFACS • Acknowledgments to the MOZAIC and MOPITT teams
MOCAGE • growing number of real-time applications in connection with atmospheric environment : monitoring protocols (Montreal, Kyoto, CLRTAP), air quality and factors affecting health (UV, pollens,…), accidental releases, campaign planning. • These applications occur at several scales and may concern the stratosphere, troposphere as well as PBL. They share many aspects (advection, parameterizations,…). • MOCAGE (Model of atmospheric chemistry at large scale) has been developped since 1999 with the objective to complement Météo-France Numerical Weather Prediction operations in the mentioned fields. • It is now a running prototype for GMES applications, inclunding real-time forecasting and chemical data assimilation.
L47 configuration for forecasts ARPEGE 2° ARPEGE 0.5° ~ 106 gridpoints, 150 tracers (gaz, aerosol bins) ALADIN 0.1°
ENSEMBLE ex. 6 (JRC) : MOCAGE (crosshatch) vs other models Release (fictive) : Dublin, 25/06/2002 12h UTC, lasting 15h Plume tracking : 60 hours
210-Pb validationPetit-Saut, French Guyana (gray, LGGE-CNRS)
ARPEGE-ALADIN NWPM J / 3h Up to 96h MOCAGE ARPEGE-ALADIN NWPM J+1 MOCAGE Daily 96h multiscale forecasts
2003 air quality forecasts verification in France (ozone, J forecast)
Skill score on ozone (200 sites, bias in mg/m3)
Ozone hole forecasts in 2002 and 2003 (no chemical data assimilation : free forecast )
UV index forecast (w. clouds) (28/08/02) http://www.meteo.fr http://www.infosoleil.com A posteriori check of NWP cloudiness Phenomenological correct. in case of mismatch
35°N How to have an impact on global UTLS fields with only 5-10 flights per day? [Cathala, Pailleux and Peuch, Tellus, 2003] • non-local assimilation • uses a (ozone equivalent latitude, q) coordinate system, similar to (PV EL, q) [Lary et al.,1995], but avoids small scale numerical structures in PV. Idea : shapes of ozone isolines are OK, but assimilation could modify gradients • a few flights per day allow to constrain the Northern hemisphere UTLS ozone, as assessed by independent ozone sounding.
MOZAIC flight level pressure MOZAIC ozone MOCAGE MOCAGE + assimilation One year (2000) with and without assimilation
MOCAGE SONDES Assimilation of MOZAIC data allows to drive long model integration with « constant » quality in the UTLS Feb. 2000 April 2000 June 2000 MOCAGE MOCAGE + assimilation
Impact of MOZAIC assimilation Mean vertical profile for the zonal band (20°N-60°N) MOCAGE MOCAGE + assimilation
MOPITT CO assimilation NCAR Kalman-Bucy filter Relative diff. (%) MOCAGE / MOPITT 500 hPa 11-30/03/2001 Relative diff. (%) MOC. + ASSIM / MOPITT 500 hPa 11-30/03/2001
Evaluation against independent data Top : CMDL & TRACE-P flights Left : one CMDL profile (11/03/2001 21°N, 157°W)
MOCAGE & EU ASSET project
GOME ozone 3d-FGAT Before assimilation After assimilation ( KNMI GOME ozone profiles retrievals )
Overview • MOCAGE is one of the first atmospheric chemistry multiscale strat.-top. suite used for daily 96h forecasts. • Data assimilation (in situ : surface, MOZAIC profiles and flight level measurements ; space : GOME, MOPITT, ENVISAT) is now in a research mode. Main problems are now « accurate » emissions specification and NRT data access. • MOCAGE is involved in : MOZAIC-III, PRISM, ASSET, SCENIC (FM5) ; ACCENT, SCOUT (FM6) and the proposals GEMS and BACC-TO-BACC. • Operations : national air quality (Prév’Air / platform with the CHIMERE model, CNRS) ; UV forecasts ; accidental releases