Vegetation and soilTownLakesSea and ocean

Summaryorganisation at M-FInterest of an externalized surfaceDescription of SURFEXThe implicit coupllingOn-going an future work at M-FHIRLAMALADIN

Some presentations CNRM (Centre national de recherches mtorologiques)GMAP (NWP) F. BouttierPROC (physical processes) F. Bouyssel, E. BazileCOOPE (scientific cooperation) D. Giard, C. Fisher, ALGO (algorithms) R. El Khatib, GMME (medium scale meteorology) J. NoilhanMC2 (surface /hydrology /carbon fluxes) P. Le Moigne, E. MartinMeso-NH (C. Lac, S. Malardel)TURBAU (turbulence/fog/town) V. MassonGMGEC (climate group)UDC (dynamic of the climate) H. DouvilleEAC (Arpege/Climat) P. Marquet

CEN (snow group avalanches)AROME : A project (F. Bouttier, G. Hello), staff from GMAP/GMME

Separate the surface schemes from the atmospheric model - difficulties for the comparison of surface model, - increased complexity of surface and atmospheric code - allows to use the same surface code for several atmospheric models or the reverse (NWP, research, climate models, off-line runs)Simulate Exchanges between surface and atmosphere (momentum, heat, water, CO2, chemical species) Litterature :Polcher et al, 1998 : A proposal for for a general interface betweeen land-surface schemes and general circulation models, Global Planetary change, 19, 263-278.Best et al, 2004 : A proposed structure for coupling tiled surfaces with the planetary boundary layer, J. of Hydrometeor.,5, 1271-1278.

The externalized surface4 surface types : the tilesSeaNatureTownLakeLakeTownSeaNatureATMOSPHERESURFACE

The Nature surface is divided in patches

Vegetation and soil : ISBA(Interface Soil Biosphere Atmosphere)Town : TEB(Town Energy Balance)Lakes :prescribed temperature, Charnock formulaSea and ocean :prescribed SST, Charnock formula

ISBA:Soil options: Force restore, 2 layers , temp, water, iceForce restore, 3 layers , temp, water, iceDiffusion, N layers , temp, water, iceVegetation options:Noilhan and Planton 89 (~Jarvis)AGS (photsynthesis and CO2 exchanges)AGS and interactive vegetationHydrology options:no subgrid processsubgrid runoff, subgrid drainageSnow options:Douville 95 (1 layer, varying albedo, varying density )Operational (Bazile, Giard)Boone and Etchevers 2000 (3 layers, albedo, density, liquid water in snow pack)TEB:Canyon approach: detailed radiation scheme (trapping shadow effect) heat storage in buildings

Initializationof PhysiographicfieldsInitializationof VariablesfieldsRunDiagnosticsThe externalized surface algorithmECOCLIMAP,FAOGTOPO30From several models,Prescribed fields 2m T and H, 10m wind, energy budget, water budgets, physiographic fields from ecoclimapFor : the whole surface (aggregated diagnostics) each type of surface (sea, lakes, vegetation, town) each patch in case of several patches in ISBA

How to use the same code in different universes? File types (MESO-Nh, netcdf, Ascii, ALADIN (soon))

- All reading (writing) orders from the surface are given by the same routineThis routine, READ_SURF, chooses the correct reading routine:

READ_SURF (file type, field)

READ_SURF for Arome file (field)READ_SURF for MesoNH file (field)READ_SURF for netcdf file (field)READ_SURF for Ascii file (field)

RunDuring run, at each timestepAlbedo, Emissivity,radiative temp.

Momentum fluxesHeat fluxWater vapor fluxCO2 fluxChemical fluxesSurfaceInitialisationBefore first time stepSurfacerunSurfacewritingOutput filesType of input fileSun positionAlbedo, Emissivity,radiative temp.Radiative fluxesSun positionAtm. ForcingRain, snow fallType of output fileAtmospheric modelsurface

What to do for the externalization Surface variables /atmospheric variable : if a physical parametrisation needs a surface variable, you need to ask the surface

In the run several mode for the surface :Enquiry : for radiation (alb, skt, emis.), or use of pseudo historical variableDiagnostic : return fluxes (for calculation of diffusion coefficientsTime-stepping : all (+temp. advance)Time stepping is implicit (mandatory for long time step) or explicit

Separation of all other parts (initialisation, diagnostic, I/O)

Development of more complete enquiry mode for analysis (soil moisture, ) not described in Best paper

Implicit coupling with the atmosphereVertical diffusionDownward sweepLower atmospheric levelSurface Ts + Fluxes on each tiles,Average fluxesUpward sweepN1Implicit coupling possible for ISBA D95

Exchanges of data (arg. of coupling_surf_atm)InputSun position, Radiative forcing, Met forcing, rain, snow, date, etcAs and BsOutputsAlbedo, Emissivity,radiative temp.

Momentum fluxesHeat fluxWater vapor fluxCO2 fluxChemical fluxes

In case of explicit coupling, A=0, B=T,q,u,vHCOUPLING ! type of coupling, 'E' : explicit,'I' : implicitKYEAR ! current year (UTC)KMONTH ! current month (UTC)KDAY ! current day (UTC)PTIME ! current time since midnight (UTC, s)KI ! number of pointsKSV ! number of scalarsKSW ! number of short-wave spectral bandsPTSUN ! solar time (s from midnight)PTSTEP ! atmospheric time-step (s)PZREF ! height of T,q forcing (m)PUREF ! height of wind forcing (m)!PTA ! air temperature forcing (K)PQA ! air humidity forcing (kg/m3)PRHOA ! air density (kg/m3)PSV ! scalar variables(chemistry:first char. in HSV:'#'(molecule/m3))! !HSV ! name of all scalar variablesPU ! zonal wind (m/s)PV ! meridian wind (m/s)PDIR_SW ! direct solar radiation (on horizontal surf.) (W/m2)PSCA_SW ! diffuse solar radiation (on horizontal surf.) (W/m2)PSW_BANDS ! mean wavelength of each shortwave band (m)PZENITH ! zenithal angle (radian from the vertical)PAZIM ! azimuthal angle (radian from North, clockwise)PLW ! longwave radiation (on horizontal surf.) (W/m2)PPS ! pressure at atmospheric model surface (Pa)PPA ! pressure at forcing level (Pa)PZS ! atmospheric model orography (m)PCO2 ! CO2 concentration in the air (kg/m3)PSNOW ! snow precipitation (kg/m2/s)PRAIN ! liquid precipitation (kg/m2/s)!PSFTH ! flux of heat (W/m2)PSFTQ ! flux of water vapor (kg/m2/s)PSFU ! zonal momentum flux (Pa)PSFV ! meridian momentum flux (Pa)PSFCO2 ! flux of CO2 (kg/m2/s)PSFTS ! flux of scalar var. (kg/m2/s)!PTRAD ! radiative temperature (K)PDIR_ALB! direct albedo for each spectral band (-)PSCA_ALB! diffuse albedo for each spectral band (-)PEMIS ! emissivity (-)!PPEW_A_COEF, PPEW_B_COEF, PPET_A_COEF, PPEQ_A_COEF, PPET_B_COEF, PPEQ_B_COEF

Main changes ARPEGE/ALADINInit. : MASTER > SUINIT > > SUNIT_SX > > STEPORun (APLPAR)Before : the ISBA subroutines are called by APLPARThe new surface temperature is solved inside the vertical diffusion routine (ACDIFUS)After : ACDIFUS is splitted : ACDIFV1, ACDIFV2, SURFEX is called between the 2ARPEGE/ALADIN : ACSURFEX > coupling_sur_atmMeso-Nh GROUNDF > coupling_sur_atmUse of pseudo historical variables (for the moment)

Present situation and short term plans for ALADINSURFEX is developed and used in Meso-NH and the AROME prototype (early 2005), explicit modeTest of implicit coupling within the 1D ARPEGE code (almost finished)Phasing the modifications of ARPEGE (APLPAR+ init+diag) (begins in october 2005 ?) finalize all interface points + some other points (e.g. antifibrilation)Develop I/O for ARP/ALADIN filesDevelop I/O in parallel computation (loop NPROMA) development of the enquiry mode (run(?) and assimilation) (temporary solution : keep the same coefficient for turb. fluxes formulation in surfex than in the old version).Many little work to do to insure conversion from old version to SURFEX / Much more for assimilationTo be tested in ALADIN mid 2006.

HIRLAM ALADINAgreement on the Best interface. Write a detailed paper on the several mode of surface callRun : more or less OKEnquiry, diagnostic, to be discussed (not yet discussed for us), also for the assimilation mode.

First objective : have the same interface for SURFEX and HIRLAM externalized surface (not necessary to have an implicit coupling coded, limitation for long time step?)

Further points : see paper ...