Reading vegetation file PFTmap.nc

10. Ghattas 29mai 2015

The reading of the vegetation map has changed in the trunk ORCHIDEE revision 2718, see also ticket #107. It is now read at the first time step in a new year. In previous versions the reading was done during the last day of December to be used for the next year. Some related parameters have also been changed. See below the different behaviour and how to use different versions of ORCHIDEE.

How it works in ORCHIDEE trunk since revision 2718

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 are control parameters for the year to be read. These parameters are only needed for the special case if VEGET_UPDATE > 1Y.

How to set up a simulation

Only the parameter VEGET_UPDATE needs to be set corresponding to the simulation. MAP_PFT_FORMAT keeps it's default value.

• Case without land use change, 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 annual land use change, 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 only 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. This parameter does not exist any more so it does not matter if it is kept or removed.

How it works in ORCHIDEE trunk older revisions than 2718, tag 1.9.6 and tag 1.9.5

Related parameters :

• LAND_USE = y / n: old name for MAP_PFT_FORMAT
  • LAND_USE = y(default) : read vegetation map on PFT format.
  • LAND_USE = n read vegetation map on Olson format.
• LAND_COVER_CHANGE = y / n : Activate stomate_lcchange calculations. Only possible if VEGET_UPDATE>0Y.
• VEGET_UPDATE, VEGET_REINIT and VEGET_YEAR: same behaviour as in recent versions, see above

How to set up a simulation

• Case without land use change, set in sechiba.card (offline simulation) or orchidee.card(coupled simulation) :
  • VEGET_UPDATE=0Y in section [UserChoices]
  • LAND_COVER_CHANGE=n 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 annual land use change, set in sechiba.card (offline simulation) or orchidee.card(coupled simulation) :
  • Case 1) Simulations with PeriodLength=1Y
    • VEGET_UPDATE=1Y in section [UserChoices]
    • LAND_COVER_CHANGE=y in section [UserChoices]
    • PFTmap.nc should not be added in section [InitialStateFiles]
    • PFTmap.nc should only be set in [BoundaryFiles]/List using the variable ${year_p1} for next coming year.

      [BoundaryFiles]
      List=(${R_BC}/SRF/${config_UserChoices_TagName}/PFTmap_1850to2005_AR5_LUHa.rc2/PFTmap_IPCC_${year_p1}.nc, PFTmap.nc)
      

  • Case 2) Simulations with PeriodLength=1M
    • VEGET_UPDATE=1Y in section [UserChoices]
    • LAND_COVER_CHANGE=y in section [UserChoices]
    • PFTmap.nc is kept in section [InitialStateFiles] : this file is used for the first year if no restart files were used.
    • PFTmap.nc is also added in section Smoothfiles using the variable ${year_p1} and the syntax 12:12:. This is done to copy the files in December each year : copy the file starting the 12'th period and updating it every 12 period. For this case it is important to always start the simulation in January. For other options, set up the as for 1Y.

      [InitialStateFiles]
      List=   (${R_BC}/SRF/${config_UserChoices_TagName}/PFTmap_1850to2005_AR5_LUHa.rc2/PFTmap_IPCC_${year}.nc, PFTmap.nc)
      ...
      [SmoothFiles]
      List=(${R_BC}/SRF/${config_UserChoices_TagName}/PFTmap_1850to2005_AR5_LUHa.rc2/PFTmap_IPCC_${year_p1}.nc, PFTmap.nc, 12:12:)