Meso-NH model

Meso-NH model

30 users laboratories

http://www.aero.obs-mip.fr/mesonh

A research model, jointly developped by Meteo-France and Laboratoire d’Aérologie (CNRS/UPS)

http://www.aero.obs-mip.fr/mesonh

http://www.meteo.fr/

Examples of Applications of Examples of Applications of Meso-NHMeso-NH

• General description of Meso-NH, Grid nesting General description of Meso-NH, Grid nesting • Clouds representation (explicit) : convective Clouds representation (explicit) : convective

events, Sc, Fog, cyclonesevents, Sc, Fog, cyclones• DiagnosticsDiagnostics• Coupling with the surface Coupling with the surface • Coupling with other models (hydrology, Coupling with other models (hydrology,

dispersion)dispersion)• ClimatologyClimatology• The physics of Meso-NH in AROMEThe physics of Meso-NH in AROME• Ways of improvements of Meso-NHWays of improvements of Meso-NH

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.

S

S

zHzzHz

•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)

DYNA

MIC

SPH

YSIC

S

Types of simulationsTypes of simulationsA broad range of resolution from synoptic scales A broad range of resolution from synoptic scales

((x~10km) to meso-scale (x~10km) to meso-scale (x~1km) to Large x~1km) to Large Eddy Simulation (Eddy Simulation (x~10m) x~10m)

• Real cases (from ECMWF, ARPEGE, ALADIN Real cases (from ECMWF, ARPEGE, ALADIN analyses or forecasts)analyses or forecasts)

• Ideal cases Ideal cases unrealistic cases unrealistic cases- Academic cases (validation of the - Academic cases (validation of the

dynamics)dynamics)- Basic studies (Diurnal cycle …) : Cloud - Basic studies (Diurnal cycle …) : Cloud

Resolving Model (CRM)Resolving Model (CRM)- To reproduce an observed reality (via - To reproduce an observed reality (via

forcings)forcings)(intercomparison : GCSS, EUROCS …)(intercomparison : GCSS, EUROCS …)

Simulations 3D, 2D, 1DSimulations 3D, 2D, 1D

Grid nesting technicsAt 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 stepsSame vertical grids.

Vaison-la-Romaine : 22 september 1992

3 nested grids : 40/10/2.5km

Instantaneous precipitations 2.5km

One-way Two-way

Stein et al., 2000

Cumulated precipitations for 9h(Obs=300mm in 6h)

One-way Two-way

Stein et al., 2000

2.5 km

10km

Vaison-la-Romaine : 22 september 1992



events, Sc, Fog, cyclones, electricityevents, Sc, Fog, cyclones, electricity• DiagnosticsDiagnostics• Coupling with the surface Coupling with the surface • Coupling with other models (hydrology, Coupling with other models (hydrology,


0°C

Autoconversion

0°C

RimingAggregation

Collection Collection

Deposition

Freezing

Nucleation

Sedimentation

Ice crystals

Snowflakes

Graupel

Hail

Cloud droplets

Cloud dropletsRaindrops

Mixed phase cloud representation with a bulk scheme

MESO-NH Explicit microphysical scheme :

Lafore Moncrieff 89

Stratiform

Density Current

Convective

HD

A tropical squall line (P.Jabouille) : Idealized

simulation according to a real case (COPT81)

U

W

Cloud droplets Rain drops

Pristine iceGraupel

Snow

Jabouille. Caniaux et al., 1994

(Keil et Cardinali, 2003)32km : 150x1508km : 145x1452km : 150x150over 51 levels

IOP8 (F<1)

IOP2a(F>1)

8 km

2 km

Monte Lema

S Pol

Ronsard

ECMWF32 km

3 Dopplerradars ( )

Orographic precipitation 3D (MAP)Orographic precipitation 3D (MAP)

How can dynamics modify the microphysics ?

Lascaux et Richard, 2005

SnowGraupel

Hail

Cloud Rain

IceIOP2a

IOP2a ( Strong convection)- Deep system (unblocked unstable case, low Fr)- Large amount of hail and graupel

Mean vertical distribution of hydrometeors

IOP8 ( Stratiform event)- Shallow system (blocked case, high Fr)- Large amount of snow

IOP8

Snow

Lascaux et Richard, 2005

Orographic precipitation 3D (MAP)Orographic precipitation 3D (MAP)

Budgets Predominant microphysical processes

Impact de la convection sur la stationnarité d’un système

Ctrl

Noc

4h-accumulated rainfall 18-22 UTC on 8 Sept. 2002

Noc = without evaparative cooling

Ctrl = with evaporative cooling

Cev. ‘95Gard ‘02

Aude ‘99

1D- budget over the MCS (convective + stratiform).

Nuissier et Ducrocq, 2006

Strong convective events on SE of FRANCEStrong convective events on SE of FRANCEHow can mycrophysics modify the dynamics ?

max : 135 mmmax : 25 mm

m mm

Quasi-stationnary MCS 13-14 Oct. 1995

Cumulated precipitation 01 UTC to 06 UTC the 14th Oct. 1995

MESO-NH, x=10km

max: 31 mm

MESO-NH, x=2.5kmOBSERVATIONS

(Ducrocq et al, 2002)

Initial conditions: ARPEGE analysis at 18UTC

mMESO-NH, x=2.5km

Initialisation Ducrocq et al

(2000)’s

max : 99 mm

Stratocumulus : Capped BLWhen the CBL is blocked by an anticyclonic subsidence

FIRE 1 case of EUROCS : Forcing terms : a LS subsidence + cooling (dl/dt<0) and moistening (dqt/dt>0) under the inversion to balance the subsidence

alti

tude

(m

)

Cloud water mixing ratio (kg/kg)

Min = 0.025 g/kg

Max = 0.6 g/kg

0h 12h 0h 12h 0h

LES simulation of the diurnal cycle (x=50m)

Observations of the base and the top cloud layer Sandu et al., 2006

rc

FOG – 1D simulation – Temporal evolution on 18h from 18TUWithout cloud droplet sedimentation

rr

rc rr With cloud droplet sedimentation

Simulation of cyclone : case of Dina7800 km, x=36km

1944 km , x=12km

720 km , x=4km

3600 km

Automatic method of Initialization : Filtering/Bogussing

Barbary et al.

Vertical cross-sections at x=4km

K

m/s

K

m/s

TCLq

EPe.

Horizontal wind

S-N W-E

Barbary et al.

Barthe et al. [2005]

+

+-

Explicite electrical scheme in Meso-NH

Local separation of charges

Transfert and transport of chargesMicrophysical and dynamical processes

Electric field

Lightning parameterizationBidirectional leader (determinist)

Vertical extension of the lightningChannel steps (probabiliste)

Horizontal extension of the lightning

Charge neutralization

E > Etrig

yes

no

Life cycle of electrical charges in a convective cell

Barthe et Pinty, JGR

Apparaition of graupel

Electrization of the cloud

Apparition of electric fieldlightning

Triggering of convectionSimulation Méso-NH





DiagnosticsDiagnostics

• Budget (heat, momentum, microphysics species, Budget (heat, momentum, microphysics species, TKE) with masksTKE) with masks

• Diagnostic fields (radar fields, comparison with Diagnostic fields (radar fields, comparison with airborne or ground observations) airborne or ground observations)

• Lagrangian trajectories Lagrangian trajectories (3 added prognostic fields) (3 added prognostic fields)

• Passive tracersPassive tracers• Tools for comparison to observations Tools for comparison to observations (Meso-NH tools : (Meso-NH tools :

Presentation of I.Mallet, Wednesday 2 pm)Presentation of I.Mallet, Wednesday 2 pm)

http://www.aero.obs-mip.fr/mesonh/doc.html/#lagrangian

http://www.aero.obs-mip.fr/mesonh/doc.html/#lagrangian

Chaboureau and Pinty (2005) : Use of radiative transfer RTTOV to MSG

x=30 km

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

Caumont, 2006

Radar reflectivityRadar reflectivity



events, Sc, Fog, cyclonesevents, Sc, Fog, cyclones• DiagnosticsDiagnostics• Coupling with the surfaceCoupling with the surface • Coupling with other models (hydrology, Coupling with other models (hydrology,


LakeTownSeaNature

Méso-NH AROME Arpège / Aladin

SURFACE

EXTERNALIZED SURFACE : Exchange of data flow at each time step between the 2

models

Atmosphere forcing Sun position Radiative fluxes

albedo emissivity radiative temperature

fluxes : Momentum, heat, water vapor, CO2, chemistry

Boundary conditions for turbulence and radiative schemes

Presentation of P.Le MoignePresentation of P.Le Moigne

OZONE le 25 Juin 2001

9 UTC

9km 3km

<30ppb

Parc Naturel VerdonMarseille

85ppb

Marseille Parc Naturel Verdon

>90ppb15 UTC >90ppb

Cousin et Tulet, 2004

Atmospheric COAtmospheric CO22 modelling : modelling :the Meso-NH modelthe 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

ISBA-A-gs

Meteorological Model LE, H, Rn, W, Ts…

Atmospheric [CO2] concentrations

AnthropogenicSea

Meso-NHMeso-NHSurfaceSurface

Lafore et al., 98

Noilhan et al. 89, 96, Calvet et al., 98

CO2 Fluxes

Atmospheric COAtmospheric CO22 modelling : May – 27 modelling : May – 27 2005 Boundary layer heterogeneity2005 Boundary layer heterogeneity

OCEAN FORESTAREA

AGRICUL.AREA

Simulated vertical cross section of the mixing ratio at 14UTC

Zi = 900m

Zi = 1600m

Atmospheric COAtmospheric CO22 modelling modellingMay – 27 2005 : comparisons May – 27 2005 : comparisons

obs/simuobs/simuSimulated vertical cross section of CO2

Ocean - Marmande

Agricultural areaForest area

Vertical cross section of observed CO2 by aircraft

oceanocean forestforest croplandcroplandforestforest croplandcropland





VidourleVidourle

GardGard

CèzeCèze

ArdècheArdèche• 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

HYDROLOGY : Development of the coupling Meso-NH-ISBA-TOPMODEL

K.Chancibault et al., CNRM/GMME/MICADO

SPRAY• Lagrangian particle model•At least 10000 particles released •Advection+Turbulence+random• Applied to the 2 Meso-NH grids

PERLEPERLE (PProgramme d’EEvaluation des RRejets L Locaux d’EEffluents)

Dispersion

Meso-NH • 2 grids (Regional x=8km, L=240km/ Local x=2km, L=60km)• 36 levels until 16km• ALADIN initialization and coupling

Meso-scale meteorology

Will be exported to AROME

Modelling system for environmental emergency





Vosges, Forêt Noire : 1.2 km

Alpes du Nord 2 km

Alpes du Sud 2 km

Pourtour méditerranéen 3 km

Auvergne 2 km

Sud-Ouest 3 km

Geographical area with Meso-NH wind climatology

Limousin 1km

Bourgogne 2 km

Quiberon 1 km

Roses Aladin 3 ansMéso-NH 95 dates Measurements

North Alps





AROME : Application of Researh to Operations at MEsoscale

Future non-hydrostatic model 2.5km resolutionDynamics 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

Arome 60s

Case of Gard, initial Case of Gard, initial bogus bogus Lame d’eau 12-22

Turadar de Nîmes

> 300 mm

Couplage : Aladin 3h Forecasts

MésoNH 4s

304 mm 274 mm

• MésoNH t= 4s , CPU = 24h20

• AROME t =60s, CPU = 2h30

Main current works of improvement for Meso-NH

1. DYNAMICS : Meso-NH computationaly too expensive (small t) – Handicap especially for chemistry simulation (a lot of species) : eulerian advection scheme, explicit temporal scheme. New eulerian advection scheme (PPM)

2. 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

Documents

Meso-NH model