Changes between Version 123 and Version 124 of DevelopmentActivities/ORCHIDEE-CNP


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Timestamp:
2016-11-07T14:42:49+01:00 (8 years ago)
Author:
dgoll
Comment:

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  • DevelopmentActivities/ORCHIDEE-CNP

    v123 v124  
    4444== 4. Re-calibration of the carbon cycle == 
    4545The calibration of ORCHIDEE-CAN of the carbon cycle in combination with the Vcmax being derived from leaf nitrogen content, leads to unrealistic C cycle (CUE, biomass stocks, biomass turnover, etc.). 
    46 Using as a guide rough ranges of observation-based estimates of aboveground biomass, LAI, CUE,  and biomass turnover, we manipulated parameters of the pipe model (TAU_SAP, KLATOSA_MIN, K_LATOSA_MAX) as well as the inversion of the rate constant for tree turnover RESIDENCE_TIME.  
     46Using as a guide rough ranges of observation-based estimates of aboveground biomass, LAI, CUE,  and biomass turnover, we manipulated parameters of the pipe model (TAU_SAP, KLATOSA_MIN, K_LATOSA_MAX) as well as the inversion of the rate constant for tree turnover RESIDENCE_TIME and the factor relating maintenance respiration to tissue N, COEFF_MAINT.  
    4747 
    48 The main issue here is, that FLUXNET GPP & energy fluxes as well as LAI estimates are poor constraints on biomass and biomass turnover when calibrating the ORCHIDEE-CAN parameter.  
    49 The range of K_LATOSA prescribed is problematic as total biomass is very sensitive to the actual values of K_LATOSA. The wider the K_LATOSA range the wider the total biomass range.  
     48The main issue with the previous calibration (Naudts et al GMD) is, that FLUXNET GPP & energy fluxes as well as LAI estimates are poor constraints on biomass and biomass turnover when calibrating the ORCHIDEE-CAN parameter. The  clear cuts in the management simulations in the GMD hide the potential biomass stocks. Even the biomass stocks estimates which exclude managed forest are smalled than the ones in ORCHIDEE. 
     49 
     50The range of K_LATOSA prescribed makes things tricky as total biomass is very sensitive to the actual values of K_LATOSA. The dynamics of K_LATOSA were several times revised and it is not clear what is going on.  
    5051 
    5152I derived a set of parameters which result in kind of okay LAI, total biomass, biomass turnover and CUE. Still some PFTs behave not really realistic, like DBF PFTs. 
    5253 
     54ISSUE with my calibration: 
    5355To facilitate the calibration I derive maintenance respiration only from leaf N and not from sapwood N too. This allows to manipulate total biomass via K_LATOSA without affecting the CUE. 
    5456It would be better to have it coupled as this adds a constraint to K_LATOSA. Best would be to include even more constraints on K_LATOSA for example hydrological constraints (like the stuff Emilie develops). 
     57 
    5558 
    5659== 5. New input files ==