Opened 9 years ago

Closed 3 years ago

#95 closed enhancement (fixed)

problem for grass growing in dynamic mortality mode

Reported by: nicolasviovy Owned by: nicolasviovy
Priority: major Milestone: ORCHIDEE 3.0
Component: Biogeochemical processes Version: trunc
Keywords: dynamic mortality in static mode Cc:

Description

with LPJ_CONST_MORTALITY false the grass cannot grow from scratch.
It comes from lpj_gap because mortality is set to 1 when npp_longterm is less than 10 which is obviously the case at the beginning of simulation. Then herb are killed and reintroduced at each stomate time step but then cannot growth.
For me it as no sense as in static mode, if condition are not favorable the vegetation is autmonatically killed by emptying the biomass when npp_longterm is null !! So I think that we should remove
the following lines:

!! 2. Grasses mortality

! For grasses, if last year's NPP is very small (less than 10 gCm{-2}year{-1})
! the grasses completely die
IF ( .NOT.control%ok_dgvm .AND. .NOT.lpj_gap_const_mort) THEN

WHERE ( PFTpresent(:,j) .AND. ( npp_longterm(:,j) .LE. npp_longterm_init ) )

mortality(:,j) = un

ENDWHERE

! Update biomass and litter pools
DO k = 1, nparts

WHERE ( PFTpresent(:,j) )

dmortality(:) = mortality(:,j) * biomass(:,j,k)


bm_to_litter(:,j,k) = bm_to_litter(:,j,k) + dmortality(:)


biomass(:,j,k) = biomass(:,j,k) - dmortality(:)

ENDWHERE

ENDDO


ENDIF

all this as been added when we merged the corrections of Sönke of the DGVM done in OCN with ORCHIDEE... But likewise I am not convinced at all by the way the static mode is treated in lpj_establish with dynamic mortality because, like in DGVM mode, new individuals are created each time (where cover is not closed) and then new biomass from sapling is added (i.e CO2_TAKEN is not null) what as no sense for me. So I would like to have you advice (in particular from Nicolas and Sebastiaan) about that ?

Change History (4)

comment:1 Changed 9 years ago by peylin

  • Owner changed from somebody to nicolasviovy
  • Status changed from new to assigned

comment:2 Changed 9 years ago by nicolasviovy

  • Status changed from assigned to accepted

comment:3 Changed 5 years ago by jgipsl

  • Milestone changed from orchidee_1_9_6 to ORCHIDEE 3.0
  • Type changed from defect to enhancement
  • Version changed from orchidee_1_9_6 to trunc

As decided during the ORCHIDEE Day 8 Sept 2017, a stop in the model has been added for the case ok_dgvm=F and LPJ_GAP_CONST_MORT=F. Done in the trunk rev [4622]

Change milestone for the ticket.

comment:4 Changed 3 years ago by nicolasviovy

  • Resolution set to fixed
  • Status changed from accepted to closed

see last comment, this problem is no more relevant so ticket is closed

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