IPCC carbon variables (c3PftFrac +contfrac)

[dsolyga]

The calculation of the IPCC variable c3PftFrac includes only grass and crops but does not include trees. The flag is_c3 is not very consistent because it means actually "c3grass & c3crop" (misunderstanding from my part). So in the code (since 1.9.6), even we calculate c3PftFrac by :

       vartmp(:)=zero
       DO j=2,nvm
          IF(is_c3(j)) THEN
             vartmp(:) = vartmp(:) + veget_max(:,j)*contfrac*100
          ENDIF
       ENDDO

It was inherited from the AR5 version :

       vartmp(:)=(veget_max(:,10)+veget_max(:,12))*contfrac*100

Moreover, the IPCC variables should not be multiplied by contfrac according Patricia. For instance, cProduct is the only IPCC variable not multiplied by contfrac. Is there a particular reason not to delete contfrac in the calculations ?

Correction

• To correct the CMIP5 post-treatment, c3PftFrac should be calculated as follow :

     c3PftFrac + treeFracPrimDec + treeFracPrimEver
  

• In the code, it is needed to change the default values of is_c3_mtc (set .TRUE. for tree meta-classes). This implies to modify the others loops using is_c3 (in routing and diffuco which use the wrong definition for this parameter).

[dsolyga]

Commit done to correct c3PftFrac : see [1091]. About the contfrac problem, it should be discussed later.

[jgipsl]

The "contfrac problem", done in trunk rev [4319], with correction in [4320].

[jgipsl]

Still to be done : adapt monitoring in coupled configurations for nbp.

[jgipsl]

Monitoring adapted in coupled configurations : ​https://forge.ipsl.jussieu.fr/igcmg/changeset/3288