Reports of technical meeting ORCHIDEE

30/09/2010

• Bug report on interpolation of a 6-hourly climate dataset (see attached file ​pdf)
  The routine 'forcing_read_interpol' in readdim2.f90 file works fine with climate datasets such as NCEP/NCAR in which:
  
  • State variables are forecasts valid 6 hours after the reference time
    
  • Flux variables are 6 hour averages starting at the reference time
    For dataset such as ERA-interim, there are different time lags for state variables and flux variables and a specific problem
    for the interpolation of SWdown. Cédric Bacour already fixed this last bug.
    To be done
  • To define different flags helping to characterize the temporal structure of a climate dataset:
    Instanteous vs Average variables, Centered vs shifted(+1 timestep) value, GMT vs local-time data
  • To auto-document any Netcdf dataset used by ORCHIDEE with these flags. This will prevent of using datasets without knowing these characteristics
  • To modify the 'forcing_read_interpol' routine in order to account for these flags
    

• Output variables
  In order to reduce the number of output variables (ie avoid 2 variables for a same physical entity), we (N. Vuichard and M. Mancip) will circulate the ALMA and CMIP5 standard and the list of output variables that are not in these 2 standards.
  Specific request :
  • to modify the standard driver for being able to specify as a list, the variables that a user wants as outputs
  • modification of the call to histdef function : loop over the outputs variables stored in a text file (like in viovy's driver)
    
• Next technical meeting : 14th October 2010 10pm
  Suggested topics :
  1. report of Didier on the externalization
  2. work on the output variables (to continue)

16/09/2010

• introduction on forge ORCHIDEE wiki : create this page
• short words from Phillipe on the organization of those meetings
  • every two weeks
  • organized by Martial, supplied by Nicolas Vuichard
  • reports are done during the meeting or just after
    and all participants have to read and perhaps correct the report
• presentation of work on externalization of parameters (see attached file ​pdf)
  • definition of readding PFTs versus Meta-Classes : discution of idea of Didier versus Sebastiaan.
    We don't keep idea that definition of PFT are in MTC sets (Sebastiaan)
    But for clearing the def file, Nicolas has proposed that we give number of MTC for each PFT per line. Accepted.
  • simplification of all parameters in code : regroup all constant modules (MTC parameters) in src_parameters and stomate_constants (all participant are agreed ).
    Discussion on initialization functions
    We have to talk to all ORCHIDEE developpers before this fusion. Two steps
    
    1. put all STOMATE constant in src_parameter
    2. fusion if needed all constant files. Some SAVE values are not parameters and lot of MTC array are SAVE and will be PARAMETER.
  • Possible flags related to the externalization
    
    1. flag CONFIG_AR5 in order to get back to the AR5 config (13 PFT with default values for all PFT parametes)
       This corresponds to only define nvm=13 and pft_to_mtc = 1 2 3 4 5 6 7 8 9 10 11 12 13
       We wont' implement the CONFIG_AR5 flag
       
    2. flag IMPOSE_PARAM : a user has developed a orchidee.def with for instance 16 PFT and has modified some parameter values
       In order to be able to use this .def file but for a run with default values (eg without removing the lines in the .def that redefined the parameter values)
       we set IMPOSE_PARAM to FALSE else we set it to TRUE.
  • All vegetation maps for variable number of PFTs will be land use like maps (result of pre-process in the right number of types).
• Spacialization of variables : Didier has asked for a list of spatialization parameters to begin change in the code.
  We decide to begin the work with vcmax_opt. Nicolas Viovy has proposed to build a map by PFTs.
  
• Next technical meeting : 30th September 2010 2pm
  Suggested topics (to be confirmed) :
  1. interpolation of 6-hourly climatology
  2. bug reported by Tea/Pierre? on water stress