Changes between Version 17 and Version 18 of DevelopmentActivities/ORCHIDEE-CN/CERA20C

Timestamp:

2017-07-26T16:36:03+02:00 (7 years ago)

Author:

pmessina

Comment:

--

DevelopmentActivities/ORCHIDEE-CN/CERA20C

@@ -109 +109 @@
 
 == 5) How the low precipitation bias in the Amazon area are fixed in ORCHIDEE  ==
+ 
 
 
+The low precipitation biases in Amazon area kill a big part of the vegetation there. The resulting vegetation distribution is not realistic at all. //
+To overcome this problem avoiding the bias correction of the precipitation field, we can set '''ALWAYS_INIT = TRUE''' in the run.def. Activating this flag we impose to vegetation to always start growing at the beginning of the growing season. By default this flag can be activated only for deciduous plants. // 
+To impose the ALWAYS_INIT to all plants we change few lines in stomate_phenology.f90: 
+
+{{{
+   !
+    !! 4. Leaf growth and biomass allocation when leaf biomass is low.
+    !!   Leaves start to grow if biometeorological conditions are favourable (::begin_leaves == TRUE) and if
+    !!   leaf growth is allowed (::allow_initpheno == TRUE).
+    !!   PFTs and then grid cells are looped over.
+    !
+
+    DO j = 2,nvm ! Loop over # PFTs
+
+       age_reset(:) = .FALSE.
+
+       DO i = 1, npts
+
+          !! Added the case((pheno_model(j) == "none") .AND. (biomass(i,j,ileaf,icarbon).LT. min_sechiba)) condition
+          !! to deal with extreme cases when the evergreen leaf biomass reaches zero 
+          IF ( (veget_max(i,j) .GT. min_sechiba) .AND. (always_init .AND. (pheno_model(j) == "none") .AND. (biomass(i,j,ileaf,icarbon) .LT. min_sechiba) ) )  THEN
+             lm_min(i) = lai_initmin(j) / sla(j)
+             biomass(i,j,ileaf,icarbon) = biomass(i,j,ileaf,icarbon) + lm_min(i)
+             biomass(i,j,iroot,icarbon) = biomass(i,j,iroot,icarbon) + lm_min(i)
+             co2_to_bm(i,j) = co2_to_bm(i,j) + ( lm_min(i) * 2 ) / dt
+          ENDIF
+
+}}}
+
+