Changes between Version 20 and Version 21 of Documentation/TrunkFunctionality4

Timestamp:

2020-03-09T14:52:53+01:00 (4 years ago)

Author:

luyssaert

Comment:

--

Documentation/TrunkFunctionality4

@@ -188 +188 @@
 In terms of grassland phenology ORCHIDEE trunk 4 follows ORCHIDEE 3.0 as closely as possible. For the moment ORCHIDEE trunk 4 is also using Nicolas's patch that enforces senescence if too many of the leaves are in the oldest leaf age class.  This patch is controlled by the LNVGRASSPATCH flag, and is set to T in the standard run.def.
 
-Part of the turnover goes into the harvest pool (harvest_fraction is now hard coded to 0.5 in stomate_turnover.f90 - see ticket #687). This simple parameter should be replaced by a grassland management module but for the moment 50% of the turnover goes into the harvest_pool (just like wood) and its decomposition is accounted for in the fluxes from the product use pool.
+Part of the turnover goes into the harvest pool (harvest_fraction is now hard coded to 0.5 for sapwood and leaves and 0 for roots in stomate_turnover.f90 - see ticket #687). This simple parameter should be replaced by a grassland management module but for the moment 50% of the turnover goes into the harvest_pool (just like wood) and its decomposition is accounted for in the fluxes from the product use pool.
 
 
@@ -196 +196 @@
 
 === Leaf area index map (r6614) ===
-Four flags have been identified that control the model behavior in terms of lai: '''ok_stomate''', '''ok_pheno''', '''impose_veg''' and '''read_lai'''. There is a 5th implicit flag which is whether restart files are used or not. If a restart file is used, the lai values will come from the sechiba restart file which is read at t=48. Given that each flag can take two values, we have 32 configurations in total. Out of these 32 configurations 10 are defined of which about 5 to 7 seem to be intended (for more details see '''Start and restart - Table 1'''). Many of the remaining 22 settings are inconsistent (i.e. running stomate to calculate a lai and reading an lai_map to prescribe lai), duplicate other settings, or would require further developments to work properly. Furthermore, the current code does not stop or warn when inconsistent settings are selected. The table (see Start and restart) proposes a scheme with 2 flags which can run with our without restart files, thus resulting in 8 different ways to control the lai in sechiba or the initial lai in stomate. The remaining 2 combinations are inconsistent and will stop the model.
+Four flags have been identified that control the model behavior in terms of lai: '''ok_stomate''', '''ok_pheno''', '''impveg''' and '''read_lai'''. There is a 5th implicit flag which is whether restart files are used or not. If a restart file is used, the lai values will come from the sechiba restart file which is read at t=48. Given that each flag can take two values, we have 32 configurations in total. Out of these 32 configurations 10 are defined of which about 5 to 7 seem to be intended (for more details see '''Start and restart - Table 1'''). Many of the remaining 22 settings are inconsistent (i.e. running stomate to calculate a lai and reading an lai_map to prescribe lai), duplicate other settings, or would require further developments to work properly. Furthermore, the current code does not stop or warn when inconsistent settings are selected. The table (see Start and restart) proposes a scheme with 2 flags which can run with our without restart files, thus resulting in 8 different ways to control the lai in sechiba or the initial lai in stomate. The remaining 2 combinations are inconsistent and will stop the model.
 
 In previous ORCHIDEE trunks, canopy structure is prescribed by a single variable called lai and the assumption of a turbid medium (Lambert-Beer). Consequently reading an lai value suffice to prescribe the entire canopy. In ORCHIDEE trunk 4, however, canopy structure has become a 3D property that can be calculated from the leaf biomass, stem biomass, the number of individuals and the assumptions that the trees follow a Poisson distribution in the horizontal plain, that the crowns are spherical and that the leaf biomass is uniformly distributed within the crowns. 
 
-The functionality to simply prescribe an lai value (either through impose or by reading a map) will need to be replaced by functionality that prescribes or reads the biomass, leaf age, and number of individuals. Given that the current lai map is based on a previous ORCHIDEE run, the same approach could be used to generate a spatially explicit canopy map that contains biomass, individuals and leaf age distribution. Nevertheless, reading an observed lai, i.e., from MODIS, and using it to force ORCHIDEE trunk 4 would require a substantial number of assumptions to turn an aggregated 1D lai value into a disaggregated 3D canopy at the PFT level.
+The functionality to simply prescribe an lai value (either through impose or by reading a map) will need to be replaced by functionality that prescribes or reads the biomass, leaf age, and number of individuals. Given that the current lai map is based on a previous ORCHIDEE run, the same approach could be used to generate a spatially explicit canopy map that contains biomass, individuals and leaf age distribution. Nevertheless, reading an observed lai, i.e., from MODIS, and using it to force ORCHIDEE trunk 4 would require a substantial number of assumptions to turn an aggregated 1D lai value into a disaggregated 3D canopy at the PFT level. For the moment the code (slowproc.f90) contains a simplified place holder that only works with NCIRC=3 and it doesn’t read leaf_age.
+
 
 ++++ CONTINUE CHECKING +++++