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)
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
zH
zzHz
•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)
DYN
AM
ICS
PH
YSIC
S
Types of simulationsTypes of simulations
A 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
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, 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,
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
0°C
Autoconversion
0°C
RimingAggregation
Collection Collection
Deposition
Freezing
Nucleation
Sedimentation
Ice crystals
Snowflakes
Graupel
Hail
Cloud droplets
Cloud droplets
Raindrops
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. ‘95
Gard ‘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 FRANCE
How can mycrophysics modify the dynamics ?
max : 135 mm
max : 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 BL
When 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
alt
itu
de (
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 18TU
Without 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
TC
Lq
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
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
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
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
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 surfaceCoupling 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
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
Anthropogenic
Sea
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/simu
Simulated vertical cross section of CO2 Ocean - Marmande
Agricultural areaForest area
Vertical cross section of observed CO2 by aircraft
oceanocean forestforest croplandcroplandforestforest croplandcropland
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
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
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
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
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
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
Arome 60s
Case of Gard, initial Case of Gard, initial bogus bogus
Lame d’eau 12-22 Tu
radar 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