Update on model developmentUpdate on model development

Meteo-FranceMeteo-France

Update on model developmentUpdate on model development

Meteo-FranceMeteo-France

CLOUDNET workshop - Exeter 5-6/04/2004CLOUDNET workshop - Exeter 5-6/04/2004François BouysselFrançois Bouyssel

SummarySummary

• Model outputs for CLOUDNET databaseModel outputs for CLOUDNET database

• Modifications in the cloudiness and radiation schemes Modifications in the cloudiness and radiation schemes

should become operational soon (beginning of May)should become operational soon (beginning of May)

• PerspectivesPerspectives

Model variables for CLOUDNET databaseModel variables for CLOUDNET database

• Global model : ARPEGE (stretched mesh ~ 25 km over west Europe)Global model : ARPEGE (stretched mesh ~ 25 km over west Europe)

36h forecasts based on 00h UTC produce hourly outputs for CLOUDNET 36h forecasts based on 00h UTC produce hourly outputs for CLOUDNET

sites (nearest grid point) sites (nearest grid point) fluxes, variables fluxes, variables

1) Model1) Model

2) New fields will be provided soon (May 2004)2) New fields will be provided soon (May 2004)

• T2m, q2m, U10m, V10m

• Altitude

• Dynamical and thermal roughness lengths

• Albedo

• Boundary layer height

• Downward solar and thermal fluxes

3) Currently delivered once a month 3) Currently delivered once a month real time (?) real time (?)

Changes in theChanges in the cloudiness and radiationcloudiness and radiation

schemesschemes

• Diagnostic schemes :Diagnostic schemes :

- Precipitation (stratiform, convective)- Precipitation (stratiform, convective)

- Cloud condensates (liquid and solid)- Cloud condensates (liquid and solid)

- Cloudiness- Cloudiness

IntroductionIntroduction

• Cloud condensates and cloudiness Cloud condensates and cloudiness inputs of radiation scheme inputs of radiation scheme

q_liquidq_ice

Radiation(SW, LW)

Neb Change in ARPEGEChange in ARPEGEsince 14th April 2003since 14th April 2003

Malcolm Brooks, University of Reading. – R.M.S. – Norwich, 2003

Pre April~14 April~14 onwards

Modifications in the new cloudiness schemeModifications in the new cloudiness scheme

• Too much 0/1 cloudiness fractionToo much 0/1 cloudiness fraction

Weaknesses of the current situation (Oper) :Weaknesses of the current situation (Oper) :

• Not enough q_ice contentNot enough q_ice content

• Modification in Xu & Randall cloudiness formulationModification in Xu & Randall cloudiness formulation

Modifications (Mod) :Modifications (Mod) :

• Convertion coefficient of potential water vapor excess to cloud Convertion coefficient of potential water vapor excess to cloud

condensate (condensate (ss) dependent on q_sat ) dependent on q_sat

• New tunings New tunings

Comparison of cloud condensates and cloudinessComparison of cloud condensates and cloudiness(Oper versus Mod)(Oper versus Mod)

Cloud condensatesCloud condensates CloudinessCloudiness

q_liquidq_liquid q_iceq_ice NebNeb

Mod :Mod :

Oper :Oper :

Mod :Mod :Oper :Oper :

SSMI climatology July 87-88-89SSMI climatology July 87-88-89

SSMIQ_iceQ_liquidQ_total

Oper :Oper :

Mod :Mod :

Radiation schemesRadiation schemes

• Very robust and efficient code (cost ratio with FMR around 20 !!)Very robust and efficient code (cost ratio with FMR around 20 !!)

• Called every time step : full consistency for cloud/radiation interactionsCalled every time step : full consistency for cloud/radiation interactions

• Improved in February 2003 : LW exchanges between atmosphere and surfaceImproved in February 2003 : LW exchanges between atmosphere and surface

1) Operationnel one (SW & LW) (Geleyn and Hollingsworth 1979)1) Operationnel one (SW & LW) (Geleyn and Hollingsworth 1979)

2) Fouquart (SW), Morcrette(LW), Radiation : FMR (Morcrette 1989)2) Fouquart (SW), Morcrette(LW), Radiation : FMR (Morcrette 1989)

• Full radiation part called every 3 hours (SW transmissivities, LW fluxes)Full radiation part called every 3 hours (SW transmissivities, LW fluxes)

• LW spectrum divided into 6 spectral regions LW spectrum divided into 6 spectral regions

• SW spectrum divided into 2 spectral regionsSW spectrum divided into 2 spectral regions

Comparison of LW radiation schemes with low level cloudComparison of LW radiation schemes with low level cloud(zoom near the surface)(zoom near the surface)

Impact of FMR15Impact of FMR15

Global tendency of QvGlobal tendency of Qv

Oper

Mod

Mod+FMR15

Zonal tendency of QvZonal tendency of Qv

PerspectivesPerspectives

• New physical package in development for ARPEGENew physical package in development for ARPEGE

Pronostic TKE schemePronostic TKE scheme

Pronostic microphysicsPronostic microphysics

New convection scheme (deep and shallow)New convection scheme (deep and shallow)

• 2km AROME prototyp in development2km AROME prototyp in development

• Wish to enlarge the use of CLOUDNET data :Wish to enlarge the use of CLOUDNET data :

Validation of research developmentValidation of research development

Which data could be used and associated error bars?Which data could be used and associated error bars?

Cloud fraction, LWP, IWP, Cloud base, PBL height, ...Cloud fraction, LWP, IWP, Cloud base, PBL height, ...

Is it possible to use programs to produce « quicklooks » graphics?Is it possible to use programs to produce « quicklooks » graphics?