Arome SCMmini-intercomparison

Sylvie Malardel

Julien Pergaud, Valery Masson,

(Arome/Méso-NH, CNRM, Météo-France)

Pedro Soares

• Arome, SCUM …

• Shallow convection schemes

• Rico composite, L80 with KFB, EDMF, EDKF

• Rico composite, L41

LCL

Arome

Arome : the NH-dynamics from IFS/ARPEGE/Aladin and a mesoscale physics from Méso-NH

ECMWF radiation scheme

SURFEX (externalized surafec scheme from Méso-NH)

CBR turbulent scheme from Méso-NH (TKE)

explicit microphysics (1 moment, 2 liquid and 3 ice species)

+ a shallow convection parametrisation

KFB directly from Méso-NH

EDMF and EDxx

SCUM : Single Column Unified Model

A 1D testbed for intercomparison of (IFS)/ARPEGE/ALADIN/AROME/(HIRLAM)/(ALARO)

physics

An option to run ARPEGE/ALADIN/AROME in a (pseudo)-1D configuration:

everything as in the 3D model + large scale forcing on Linux PC

Which shallow convection scheme for Arome ?

Do we need one ?

KFB : « copy » of the deep convection scheme developed in Méso-NH (Bechtold et al, 1993) + statistical cloud scheme (Chaboureau and Bechtold, 2002)

Mass flux with LCL triggering and CAPE closure

EDMF : Mass flux scheme developed by P. Soares (SOARES et al, 2004) in Méso-NH with « light » technical modifications

EDKF : « modified » EDMF (Pergaud, Malardel, Masson, this summer) with

Dry updraft from Lappen and Randall, 2001

Cloudy updraft from Kain and Fritsch, 1990

EDKF updraftprototype

LCL

uM

uu

χc

χf(χ)dχMt0

1

1χc

χ)f(χ)dχ(Mt

From Kain and Fritsch,1990

(surface fluxes)SURFEX

e

w'r'rr surf

tu

t

3/1

up

v

Lw'θ'g

CM surf

ref

u

e

w'θ'θθ surf

lu

l

dn

u

L

MCE )1(

up

u

L

MCD )1(

From Lappen and Randall,2001

Rico : high resolution composite case

No shallow convection scheme

Explicit cloud under a strong inversion

Rico : high resolution composite case

KFB shallow convection scheme (Bechtold et al, 1993)with statistical cloud scheme (Chaboureau and Bechtold, 2002)

Results are identical if shallow+deep

Rico : high resolution composite case

EDMF (Soares et al, 2004)

with statistical cloud scheme

+36 h

Rico : high resolution composite case

EDKF (Pergaud, Malardel, Masson)

+36 h

Rico : high resolution composite case

EDKF (Pergaud, Malardel, Masson)

with subgrid autoconversion

Rain specific content (g/kg)

Rico : high resolution composite case

EDKF without and with subgrid autoconversion

AUCV

no AUCV

no AUCV

AUCVAUCV

AUCV AUCV

no AUCV no AUCV

no AUCV

Rico : composite case with Arome resolution (L41)

L41 L80

L80L41

L80L41

Rico : Arome resolution (L41) composite case

L80L41

L80L41

L80L41

L80L41

t=24h t=24h

23-24haverage

23-24haverage