Update on model developments: Meteo-France Update on model developments: Meteo-France NWP model / clouds and turbulenceNWP model / clouds and turbulenceUpdate on model developments: Meteo-France Update on model developments: Meteo-France NWP model / clouds and turbulenceNWP model / clouds and turbulence

CLOUDNET Workshop / Utrecht 21-22/10/2002

Jean-Marcel PiriouCentre National de Recherches MétéorologiquesGroupe de Modélisation pour l’Assimilation et la Prévision

PHYSICS

Global ARPEGEAquaplanet mode

SCM ARPEGE (EUROCS, GATE, TOGA,BOMEX, ARM, …)

LAM ALADIN / coupled / 10 km

Global stretched ARPEGE / 4DVAR-ass. / 20 to 200 km

Global regular ARPEGE / 4DVAR-ass. / 66 km

Present operational schemes

Under progress

Radiation Geleyn and Hollingsworth (1979), Ritter and Geleyn (1992)

More accurate infra-red exchanges between surface and layers

Grid-scale cloud scheme

Diagnostic in ql/i, all supersaturation removed, liquid/ice condensation T, melting/ freezing/ evaporation/ Kessler (1979), Clough and Franks (1991)

Prognostic ql/i, qr/s

Subgrid-scale cloud scheme (convection)

mass-flux scheme, CISK-type closure and triggering, water

vapour budget using a Kuo-type closure, downdrafts, momentum flux

Modified trigger functions (TKE, CIN)

Turbulence 1st order closure scheme after Louis (1979), Louis and al. (1981), using a flux-gradient K-theory with Ri dependency, variable roughness lengths over sea (Charnock)

PrognosticTKE scheme, mixing « Betts » conservative variables thetal and qt instead of theta and qv

Perspectives operational modelPerspectives operational model ( (GCM 20-200km GCM 20-200km

ARPEGEARPEGE + + LAMLAM 10km 10km ALADINALADIN))

• March towards new prognostic cloud and turbulence March towards new prognostic cloud and turbulence

variables: ql/i, qr/s, TKE, w_ud, w_ddvariables: ql/i, qr/s, TKE, w_ud, w_dd

• EUROCS: 3 transition cases (well posed lateral conditions EUROCS: 3 transition cases (well posed lateral conditions

to compare CRMs to GCMs or LAMs)to compare CRMs to GCMs or LAMs)

• Model to satellite, data assimilation cycleModel to satellite, data assimilation cycle

• CLOUDNET: (long time series, detailed profiles) colocated CLOUDNET: (long time series, detailed profiles) colocated

ql/i, qr/s, PBL depth, cloudiness, close TEMP data to ql/i, qr/s, PBL depth, cloudiness, close TEMP data to

provide in-situ validation of new microphysics / turbulenceprovide in-situ validation of new microphysics / turbulence

Perspectives 2: a CRM in operations around 2008!...Perspectives 2: a CRM in operations around 2008!...

• 2003: first tests of the existing CRM méso-NH2003: first tests of the existing CRM méso-NH physics in physics in

the the ALADIN-NH ALADIN-NH 2.5km2.5km dynamical core dynamical core need for need for

validations within CLOUDNET?validations within CLOUDNET?