Reading vegetation file PFTmap.nc

10. Ghattas 29mai 2015

How it works in ORCHIDEE trunk since revision 27xx

Following parameters are related to the vegetation map and can be set in run.def:

• MAP_PFT_FORMAT = y/n : Old name for MAP_PFT_FORMAT was LAND_USE.
  • MAP_PFT_FORMAT = y(default) : The vegetation will be initialized reading a netcdf file on PFT format, PFTmap.nc. Same number of PFTs must be found in the file as used during run time. It is possible to use another file name using the parameter VEGETATION_FILE.
  • MAP_PFT_FORMAT = n : The vegetation will be initialized by reading a OLSON type vegetation file. The default netcdf file is carteveg5km.nc. The file name can be changed using the parameter VEGETATION_FILE. No change in vegetation can be done using this file format.

• VEGET_UPDATE = xY : update the vegetation every x years
  • VEGET_UPDATE = 0Y(default) : no change in vegetation. PFTmap.nc is read only if starting without restart files.
  • VEGET_UPDATE = 1Y : update the vegetation in the beginning of each year. The netcdf file PFTmap.nc corresponding to the current year of simulation must be available.
  • VEGET_UPDATE > 1Y : update only at a certain frequency

• VEGET_REINIT and VEGET_YEAR control parameters for the year to be read. These parameters are only neede for the special case if VEGET_UPDATE > 1Y.

How to set up a simulation

• Case without land use change, VEGET_UPDATE=0Y, set in sechiba.card (offline simulation) or orchidee.card(coupled simulation) :
  • VEGET_UPDATE=0Y in section [UserChoices]
  • PFTmap.nc should be set only in List in section [InitialStateFiles]

    [InitialStateFiles]
    List=   (${R_BC}/SRF/${config_UserChoices_TagName}/PFTmap_1850to2005_AR5_LUHa.rc2/PFTmap_IPCC_${year}.nc, PFTmap.nc)
    

• Case with land use change, VEGET_UPDATE=1Y, set in sechiba.card (offline simulation) or orchidee.card(coupled simulation) :
  • VEGET_UPDATE=1Y in section [UserChoices]
  • PFTmap.nc should not be added in section [InitialStateFiles]
  • PFTmap.nc should be set in [BoundaryFiles]/List using the variable $year. For simulations with PeriodLenght=1M to optimize the copy of files, section SmoothFiles can be used. But the syntax is more complex and it is not recommended.

    [BoundaryFiles]
    List=(${R_BC}/SRF/${config_UserChoices_TagName}/PFTmap_1850to2005_AR5_LUHa.rc2/PFTmap_IPCC_${year}.nc, PFTmap.nc)
    

For both cases LAND_COVER_CHANGE can be removed for [UserChoices] section.