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Meso-NH model

Meso-NH model. A research model, jointly developped by Meteo-France and Laboratoire d’Aérologie (CNRS/UPS). 30 users laboratories. http://www.aero.obs-mip.fr/mesonh. Examples of Applications of Meso-NH. General description of Meso-NH, Grid nesting

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Meso-NH model

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  1. Meso-NH model A research model, jointly developped by Meteo-France and Laboratoire d’Aérologie (CNRS/UPS) 30 users laboratories http://www.aero.obs-mip.fr/mesonh

  2. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  3. General description of Meso-NH • Anelastic equations with the pseudo-incompressible system of Durran • Vertical coordinate following the terrain : (Gal Chen and Sommerville, 1975) • Temporal discretization : Purely explicit leap-frog scheme • Advection scheme : 2nd order and 4th order eulerian schemes • Spatial discretization : Arakawa C grid • Grid nesting : One-way/Two-way • Initial fields and LBC (radiative open) from ECMWF/ARPEGE/ALADIN. DYNAMICS • Turbulence : 1.5 order closure Cuxart-Bougeault-Redelsperger (2000) • Convection : Kain-Fritsch (1993) revised by Bechtold et al. (2001) • Microphysical scheme : Bulk schemes at 1-moment or 2-moments. Up to 7 prognostic species: vapor (rv), cloud (rc), rain (rr), pristine ice (ri), snow (rs), graupel (rg), hail (rh) • Radiation : ECMWF package • Chemical on-line scheme : Gazeous and aerosols (Presentation C.Mari, Thursday) • Externalized surface model(Presentation P.Le Moigne, this afternoon) PHYSICS

  4. Types of simulations • A broad range of resolution from synoptic scales (Dx~10km) to meso-scale (Dx~1km) to Large Eddy Simulation (Dx~10m) • Real cases (from ECMWF, ARPEGE, ALADIN analyses or forecasts) • Ideal cases  unrealistic cases • - Academic cases (validation of the dynamics) • - Basic studies (Diurnal cycle …) : Cloud Resolving Model (CRM) • - To reproduce an observed reality (via forcings) • (intercomparison : GCSS, EUROCS …) • Simulations 3D, 2D, 1D

  5. Grid nesting technics At every time step : The Coarse Model (CM) gives the lateral boundary conditions to Fine Model (FM) by interpolation One-way : the FM doesn’t influence the CM Two-way : CM fields are relaxed to the average of FM fields (all variables except TKE) A single constraint : an integer ratio between the resolutions and the time steps Same vertical grids.

  6. Vaison-la-Romaine : 22 september 1992 One-way Two-way 3 nested grids : 40/10/2.5km Instantaneous precipitations 2.5km Stein et al., 2000

  7. Vaison-la-Romaine : 22 september 1992 One-way Two-way 2.5 km Cumulated precipitations for 9h (Obs=300mm in 6h) 10km Stein et al., 2000

  8. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones, electricity • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  9. Mixed phase cloud representation with a bulk scheme Nucleation Autoconversion Ice crystals Snowflakes Graupel Hail Cloud droplets Deposition Riming Aggregation Freezing 0°C 0°C Cloud droplets Raindrops Collection Collection Sedimentation

  10. MESO-NH Explicit microphysical scheme :

  11. U Convective Stratiform W H D Density Current q A tropical squall line (P.Jabouille) : Idealized simulation according to a real case (COPT81) Lafore Moncrieff 89

  12. Cloud droplets Rain drops Graupel Pristine ice Snow Jabouille. Caniaux et al., 1994

  13. 2 km Monte Lema 3 Doppler radars ( ) S Pol Ronsard 8 km Orographic precipitation 3D (MAP) How can dynamics modify the microphysics ? ECMWF32 km 32km : 150x150 8km : 145x145 2km : 150x150 over 51 levels (Keil et Cardinali, 2003) IOP2a (F>1) IOP8 (F<1) Lascaux et Richard, 2005

  14. Orographic precipitation 3D (MAP) Mean vertical distribution of hydrometeors IOP8 IOP2a Ice Snow Graupel Snow Hail Cloud Rain • IOP2a ( Strong convection) • - Deep system (unblocked unstable case, low Fr) • Large amount of hail and graupel IOP8 ( Stratiform event) - Shallow system (blocked case, high Fr) - Large amount of snow Budgets  Predominant microphysical processes Lascaux et Richard, 2005

  15. 4h-accumulated rainfall 18-22 UTC on 8 Sept. 2002 Cev. ‘95 Gard ‘02 Noc Aude ‘99 1D- q budget over the MCS (convective + stratiform). Ctrl Ctrl = with evaporative cooling Noc = without evaparative cooling Strong convective events on SE of FRANCE Impact de la convection sur la stationnarité d’un système How can mycrophysics modify the dynamics ? Nuissier et Ducrocq, 2006

  16. MESO-NH, x=2.5km m MESO-NH, x=2.5km max : 99 mm Initialisation Ducrocq et al (2000)’s max: 31 mm Quasi-stationnary MCS 13-14 Oct. 1995 MESO-NH, x=10km OBSERVATIONS m mm max : 25 mm max : 135 mm Initial conditions: ARPEGE analysis at 18UTC Cumulated precipitation 01 UTC to 06 UTC the 14th Oct. 1995 (Ducrocq et al, 2002)

  17. Cloud water mixing ratio (kg/kg) Max = 0.6 g/kg LES simulation of the diurnal cycle (Dx=50m) altitude (m) Min = 0.025 g/kg 0h 12h 0h 12h 0h Observations of the base and the top cloud layer Stratocumulus : Capped BL When the CBL is blocked by an anticyclonic subsidence FIRE 1 case of EUROCS : Forcing terms : a LS subsidence + cooling (dql/dt<0) and moistening (dqt/dt>0) under the inversion to balance the subsidence Sandu et al., 2006

  18. With cloud droplet sedimentation q rc rr FOG – 1D simulation – Temporal evolution on 18h from 18TU Without cloud droplet sedimentation rc q rr

  19. 7800 km, Dx=36km 1944 km , Dx=12km 720km , Dx=4km 3600km Simulation of cyclone : case of Dina Automatic method of Initialization : Filtering/Bogussing Barbary et al.

  20. Vertical cross-sections at Dx=4km K K m/s m/s W-E S-N Horizontal wind Barbary et al.

  21. + - + Explicite electrical scheme in Meso-NH Local separation of charges Transfert and transport of charges Microphysical and dynamical processes Electric field no E > Etrig yes Lightning parameterization Bidirectional leader (determinist) Vertical extension of the lightning Channel steps (probabiliste) Horizontal extension of the lightning Charge neutralization Barthe et al. [2005]

  22. Triggering of convection Apparaition of graupel Electrization of the cloud Apparition of electric field lightning Life cycle of electrical charges in a convective cell Simulation Méso-NH Barthe et Pinty, JGR

  23. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  24. Diagnostics • Budget (heat, momentum, microphysics species, TKE) with masks • Diagnostic fields (radar fields, comparison with airborne or ground observations) • Lagrangian trajectories (3 added prognostic fields) • Passive tracers • Tools for comparison to observations (Meso-NH tools : Presentation of I.Mallet, Wednesday 2 pm) http://www.aero.obs-mip.fr/mesonh/doc.html/#lagrangian

  25. Chaboureau and Pinty (2005) : Use of radiative transfer RTTOV to MSG Dx=30 km

  26. Radar reflectivity Observed reflectivity Simulated reflectivity (radar de Bollène le 8 sep. 2002 à 21 UTC, élévation=1,2°) Caumont, 2006

  27. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  28. EXTERNALIZED SURFACE : Exchange of data flow at each time step between the 2 models Boundary conditions for turbulence and radiative schemes Méso-NH AROME Arpège / Aladin albedo emissivity radiative temperature fluxes : Momentum, heat, water vapor, CO2, chemistry Atmosphere forcing Sun position Radiative fluxes SURFACE Lake Town Sea Nature Presentation of P.Le Moigne

  29. 3km 9km 9 UTC 85ppb <30ppb 15 UTC >90ppb >90ppb Parc Naturel Verdon Marseille Marseille Parc Naturel Verdon OZONE le 25 Juin 2001 Cousin et Tulet, 2004

  30. Atmospheric CO2 modelling :the Meso-NH model Online coupling with the surface scheme ISBA-A-gs :  CO2 surface fluxes : - assimilation (<0) CO2 absorption by vegetation - respiration (>0) CO2 emissions from ecosyst. depends on temperature - anthropogenic emissions (>0) and ocean fluxes (<0 in our latitude) Feedback : CO2 concentrations variations from the atmosphere to the surface Meso-NH Surface Meteorological Model LE, H, Rn, W, Ts… ISBA-A-gs CO2 Fluxes Atmospheric [CO2]concentrations Anthropogenic Sea Noilhan et al. 89, 96, Calvet et al., 98 Lafore et al., 98

  31. Simulated vertical cross section of the mixing ratio at 14UTC Zi = 1600m Zi = 900m OCEAN FOREST AREA AGRICUL. AREA Atmospheric CO2 modelling : May – 27 2005 Boundary layer heterogeneity

  32. Vertical cross section of observed CO2 by aircraft Forest area Agricultural area Atmospheric CO2 modellingMay – 27 2005 : comparisons obs/simu Simulated vertical cross section of CO2 Ocean - Marmande ocean forest cropland forest cropland

  33. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  34. Ardèche Cèze Gard Vidourle HYDROLOGY : Development of the coupling Meso-NH-ISBA-TOPMODEL K.Chancibault et al., CNRM/GMME/MICADO • TOPMODEL (Beven and Kirkby, 1979) distributed hydrologic model with one model by basin : 9 basins (200-2200 km²) • Objectives : - Flow and rapide flood forecasts - Retroaction of the hydrology on the atmosphere - Available for AROME

  35. Modelling system for environmental emergency Meso-scale meteorology Meso-NH • 2 grids (Regional Dx=8km, L=240km/ Local Dx=2km, L=60km) • 36 levels until 16km • ALADIN initialization and coupling • Lagrangian particle model • At least 10000 particles released • Advection+Turbulence+random • Applied to the 2 Meso-NH grids SPRAY • PERLE(Programmed’Evaluationdes Rejets Locauxd’Effluents) Dispersion Will be exported to AROME

  36. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  37. Geographical area with Meso-NH wind climatology Bourgogne 2 km Auvergne 2 km Vosges, Forêt Noire : 1.2 km Quiberon 1 km Limousin 1km Alpes du Nord 2 km Sud-Ouest 3 km Alpes du Sud 2 km Pourtour méditerranéen 3 km

  38. Measurements Roses Aladin 3 ans Méso-NH 95 dates North Alps

  39. Examples of Applications of Meso-NH • General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective events, Sc, Fog, cyclones • Diagnostics • Coupling with the surface • Coupling with other models (hydrology, dispersion) • Climatology • The physics of Meso-NH in AROME • Ways of improvements of Meso-NH

  40. AROME : Application of Researh to Operations at MEsoscale Future non-hydrostatic model 2.5km resolution Dynamics based on ALADIN-NH (semi-implicite, semi-lagrangian) Data assimilation ALADIN 3D-VAR Physics based on Méso-NH : microphysics ICE3, Turbulence 1D, shallow convection, externalised surface http://www.cnrm.meteo.fr/aladin/aladin2/traceMP/AROMErunMP.html

  41. Case of Gard, initial bogus Lame d’eau 12-22 Tu radar de Nîmes MésoNH 4s Arome 60s 304 mm 274 mm > 300 mm Couplage : Aladin 3h Forecasts • MésoNH • Dt= 4s , CPU = 24h20 • AROME • Dt =60s, CPU = 2h30

  42. Main current works of improvement for Meso-NH • DYNAMICS : Meso-NH computationaly too expensive (small Dt) – Handicap especially for chemistry simulation (a lot of species) : eulerian advection scheme, explicit temporal scheme.  New eulerian advection scheme (PPM) • PHYSICS: • Boundary layer clouds (Cu, Sc) at meso-scale (2km): interaction between shallow convection scheme, turbulence and cloud scheme • Radiation : revised, for overlapping cloud layers • Microphysics : Bulk 2 moment schemes for LES • Improvement of sedimentation advection

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