Changes between Version 3 and Version 4 of Parameter_handling


Ignore:
Timestamp:
2020-03-31T12:13:17+02:00 (4 years ago)
Author:
luyssaert
Comment:

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  • Parameter_handling

    v3 v4  
    22= Documenting and archiving ORCHIDEE parameters = 
    33 
    4 '''Initial draft:''' Sebastiaan Luyssaert (29/03/2020) 
     4'''Initial draft:''' Sebastiaan Luyssaert (29/03/2020)[[BR]] 
    55 
    6 '''Objective:''' This pages documents the work around the documentation and handling of all ORCHIDEE parameters 
     6'''Attachment: ''' [attachment:Documenting_and_archiving_parameters.docx Document summarizing initial discussion between SL, PP and AD] [[BR]] 
     7 
     8'''Objective:''' document the work around the documentation and handling of all ORCHIDEE parameters [[BR]] 
    79  
    810=== Rational === 
     
    1517Few are the cases where observed parameter values can enter the model without any further consideration. This is due to:  (1) scaling issues between the observation (site) and the model (pixel), (2) spatial homogenization in the model which ignores the observed spatial heterogeneity, (3) the use of PFTs which cannot be correctly represented in the model unless their exact phylogenetic composition is known, (4) non-linearity of parameters making it undesirable to simply use the mean observed parameter values in the model, and (5) shortcomings in the models which are compensated for in the parameter values. The C-only versions of ORCHIDEE implicitly account for the N-cycle in their parameter values, else no observations could ever have been matched. Where some of these issues are explicitly accounted for others are still implicitly accounted for in the processing chain (Fig. 1)  
    1618 
     19[[Image(Presentation4.jpg, 1000px, align=center)]][[BR]]\\ 
     20'''Fig. 1.''' The different processing steps from the observed parameter values up to a model parameter used in a specific model version. 
     21 
    1722=== Sources of parameter values ===  
    1823Some of the main sources of parameters values are: (1) individual research papers reporting experimental or monitoring results, (2) meta-analysis reporting best-available knowledge, (3) analyses of remote sensing data, (4) existing trait and parameter data bases, and (5) observational data bases which could be used to derive parameter values.  
     
    2328 
    2429This database should enable back traceability implying that none of its entries should ever be overwritten but that sufficient labels should be present to filter out obsolete parameters (no longer used by ORCHIDEE) and obsolete values (no longer considered best-available). This criterion has implications for model development; if in ORCHIDEE we change the definition of a parameter we should also change its name. Ideally this database should be shared and maintained by several modelling groups as we all depend on the same primary sources for our initial parameter values. 
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    26   
    27 '''Fig. 1.''' The different processing steps from the observed parameter values up to a model parameter used in a specific model version. 
     30 
    2831 
    2932=== Querying the database === 
     
    4548 
    4649The quality control and quality assurance chain. Note that this is only part of the QC/QA chain. The chain continues with an svn server for ORCHIDEE, commits that are backed up by a ticket, groups of tickets that are backed up by a mile stones. Milestones that come with trusting and reference simulations, simulations that are evaluated against a set of benchmarks and all of this being properly tied together in publications (peer reviewed or wiki). 
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    49 Document by Sebastiaan summarizing initial discussion between SL, PP and AD: [attachment:Documenting_and_archiving_parameters.docx] 
    50