Changeset 3972

Timestamp:
2016-12-16T12:21:40+01:00 (7 years ago)
Author:
nicolas.vuichard
Message:

Update of the photosynthesis scheme.
It includes:

  • the use of a mesophyll conductance based on Yin et al. (2009)
  • flags that have been added in order to apply a water stress on Vcmax, stomatal conductance (gs), or mesophyll conductance (gm). The flags are named stress_vcmax, stress_gs and stress_gm, respectively and are PFT-variables. By default, stress_vcmax is set to 1, and the 2 others flags to 0, for all PFTs. This corresponds to the former choice of applying the stress on Vcmax. A suggested parametrization is to move the stress on gs and gm, for all PFT and to keep in addition the stress on Vcmax for C4 species. This gives:

STRESS_GS=1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.
STRESS_GM=1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.,1.
STRESS_VCMAX=0.,0.,0.,0.,0.,0.,0.,0.,0.,0.,1.,0.,1.

  • Bug correction on leaf boundary layer conductance (gb). A factor 1000 was added by error. gb is expressed here in (molH2O m-2 s-1) not in (mmolH2O m-2 s-1).
  • Correction of units for a diagnostic variable, gsmean. See ticket #312
  • Correction for avoiding division by 0 in some cases. See ticket #294
  • values of the "a1" parameter for C4 species have changed. It now corresponds to the value reported by Collatz et al. (1992, ie. this is equivalent to m=4)
  • a new optional formulation for the water stress function based on the work of Salir Meridja (suggested by Matthieu Guimberteau): https://forge.ipsl.jussieu.fr/orchidee/attachment/wiki/DevelopmentActivities/CMIP6/DevelopmentsCMIP6/hydric_stress/these_meridja_STRESS.pdf. It is activated with the flag NEW_WATSTRESS. This formulation has two parameters: the old "pcent" parameter and alpha_watstress
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