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

Timestamp:

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

Author:

dgoll

Comment:

--

DevelopmentActivities/ORCHIDEE-CNP

@@ -44 +44 @@
 == 4. Re-calibration of the carbon cycle ==
 The 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.).
-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. 
+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 and the factor relating maintenance respiration to tissue N, COEFF_MAINT. 
 
-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. 
-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. 
+The 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.
+
+The 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. 
 
 I 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.
 
+ISSUE with my calibration:
 To 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.
 It 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).
+
 
 == 5. New input files ==